Masonry Wall BOR11999 VIC Manual Bk4

Masonry Design Guide

www.boral.com.au/masonry Updated July 2005

BORAL MASONRY

Build something great™

SEGMENTAL BLOCK RETAINING WALLS VICTORIA BOOK 4

A2 July 2005 | BORAL MASONRY DESIGN GUIDE

Victoria Book 4 A

A Introduction

Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A2

Fast Find Product & Application Guide . . . . . . . . . . . . . . . . . A3

Products @ a Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A4

About This Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A6

B Planning & Design

C Gardenwall®

Gardenwall Product Information . . . . . . . . . . . . . . . . . . . . . . C2

Selection & Construction Guidelines . . . . . . . . . . . . . . . . . . . C3

Curved Walls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C4

D Heathstone®

HeathstoneProduct Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D2

Gravel-Fill Construction Guidelines . . . . . . . . . . . . . . . . . . . . D3

Curved Wall Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . D4

Step Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D4

Step Tread and Cap Unit Installation . . . . . . . . . . . . . . . . . . . D5

Corner Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D6

No-Fines Concrete Wall Construction . . . . . . . . . . . . . . . . . . D7

E Keystone® & Pyrmont®

Keystone Product Information . . . . . . . . . . . . . . . . . . . . . . . . E4

Pyrmont Product Information. . . . . . . . . . . . . . . . . . . . . . . . . E5

Gravel-Fill Wall Selection &Construction Guidelines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . E6

Typical Installation Detail . . . . . . . . . . . . . . . . . . . . . . . . . . . . E8

No-Fines Concrete Wall Construction Guidelines . . . . . . . . . . . . . . . . . . . . . . . . E11

Geogrid Soil-Reinforced Wall Construction Guidelines. . . . . . . . . . . . . . . . . . . . . . . . E13

Typical Specification for Keystone/Pyrmont Retaining Walls . . . . . . . . . . . . . . . . . . . E15

F Custom Engineered Walls

Engineered Retaining Walls . . . . . . . . . . . . . . . . . . . . . . . . . . F2

Keysteel Product Information. . . . . . . . . . . . . . . . . . . . . . . . . F4

Typical Soil-Anchor Application. . . . . . . . . . . . . . . . . . . . . . . . F6

Typical Rock-Anchor Application . . . . . . . . . . . . . . . . . . . . . . . F7

Typical Seawall Application. . . . . . . . . . . . . . . . . . . . . . . . . . . F8

Typical Terraced Wall Application . . . . . . . . . . . . . . . . . . . . . . F9

Typical Fencing Application. . . . . . . . . . . . . . . . . . . . . . . . . . F10

Typical Railing & Barrier Application . . . . . . . . . . . . . . . . . . . F11

The information presented herein is supplied in good faith and to the best of our knowledge was accurate at the time of preparation. No responsibility can be accepted byBoral or its staff for any errors or omissions. Users are advised to make their own determination as to the suitability of this information in relation to their particular purposeand specific circumstances. Since the information contained in this document may be applied under conditions beyond our control, no responsibility can be accepted by usfor any loss or damage caused by any person acting or refraining from action as a result of this information.

An Introduction to Segmental Block Retaining Walls . . . . . . . . . . . . . . . . . . . . . B2

Site Investigation – Preliminary Design . . . . . . . . . . . . . . . . . B6

PAG

E

PAG

E

A3BORAL MASONRY DESIGN GUIDE | July 2005

Victoria Book 4 A

For technical support and sales office details please refer to the outside back cover

The quickest way to find a Boral Masonry Segmental Block Retaining Wall Solution.

Simply follow the FAST FIND guide on the right hand side of the table.

Vertical

Surcharge

Loading

Nil

≤ 5kPa

≤ 5kPa

or

≤ 1:4

Sloped

Backfill

≤ 25kPa

> 25kPa

Wall Height

(mm)

≤ 1125

≤ 1600

≤ 3000

> 3000

> 6000

Wall

Type

Set Back

Vertical

Set Back

Property

Boundary

Not

Boundary

Vertical

Set Back

Vertical

Set Back

Gar

denw

all

Hea

thst

one

Pyrm

ont

Key

stone

Key

stee

l

Core

Fill

ed B

lock

D E E ✱

C E

D✤ E✤ E✤ ✱

E✤

✱

E★ E★ ✱

E★E★

E★

F

F

Select your application criteria from the left hand columns

Go straight to the book section indicated by the letter at the intersection of application rows and product columns (e.g. Section E in this example)

Please refer to Book 1, Boral Masonry Design Guide and Book 2, Boral Masonry Blocks & Bricks Guide

Requires ‘No-fines Concrete Backfill ’ or ‘Geogrid’ systems

Requiring ‘Geogrid’ systems

✱

✤

★

BORAL

MASONRY

SEGMENTAL

BLOCK

RETAINING

WALLS PRODUCT

Fast Find

a Boral

Solution1

2

Max. wall heights disclaimer:

The gravity wall heights are maximum heights calculated in accordance with CMAA MA-53 Appendix D guidelines and a qualified engineer should confirm the suitability of the productfor each intended application. As such, due consideration must be given to but not limited to:

• Cohesion,

• Dry backfill: no ingress of any water into the soil behind the retaining wall,

• All retaining walls are designed for zero surcharge unless noted otherwise.

These walls are intended for structure Classification A walls only as defined in AS4678 Earth Retaining Structures as being where failure would result in minimal damage and/or loss of access.


Victoria Book 4 AAA AAAA4 Ak 4 ookkoookBBooBBia rriiaaaatorrcttoViiiiccVV

Landscape

Retaining Wall Systemsfor low-height domestic and commercial

garden beds and retaining wall applications

• Gardenwall®

Boral Gardenwall is ideal for gravity wall installationsof less than 1.125m wall height. The blocks are laidwith a slight set-back, and are located by a lug alongthe back edge. Gardenwall can also be used for curvedwall applications.

• Heathstone® & Heathstone® Grand

Boral Heathstone retaining wall systems combine theattractive impression of natural hewn stone, the eleganceof a vertical wall and the simplicity of mortarlessinstallation. Various installation formats cater for wallsup to 0.97m height. Heathstone Grand double-lengthblocks are particularly effective in larger installations.

A5BORAL MASONRY DESIGN GUIDE | July 2005

Victoria Book 4 AA A4 k 4 ok BooBo Bia oriatorictVicV

Engineered

Retaining Wall Systemsfor domestic and commercial landscaping, roadside

and custom engineered retaining wall applications

• Pyrmont®

Boral Pyrmont retaining walls are a modern-day link toour pioneer heritage. Pyrmont combines modernengineering versatility with the elegance of a verticalwall and the style of hand-finished natural stone.Pyrmont gravity or soil reinforced retaining wall systemscan be engineered for applications up to 6m heightand can accommodate gentle curves and stepinstallations.

• Keysteel™ Custom Engineered Retaining

Wall Systems

Boral Keysteel is a high performance engineeredretaining wall system for applications requiring wallheights in excess of 6m and/or where critical surchargeloadings are present. Boral Keysteel is an internationallyproven system that integrates the superior strengthand durability of Keysteel blocks with steel-ladder soil-reinforcement to provide engineered solutions for themost demanding retaining structures.

• Keystone®

Boral Keystone walls have been proven time-and-time-again, by engineers, architects, councils, roadauthorities and landscapers throughout Australia.Keystone walls can cater for a wide range ofapplications from low height gravity walls to geogridsoil reinforced applications up to 12m wall height.Keystone walls can be constructed as near verticalwith curves as tight as 1m radius, or set-back. Blocksare available in a wide selection of colours and insplitface or flushface formats.


Victoria Book 4 A

A Guided Tour of a Typical Product Information Page

Product pages are laid out in a consistent manner to assist with easy selection and specification

of Boral Masonry products.

Product Range, Book andPage Identification

Product Name and otheridentifying features

Product informationrelating to features,applications, andaccessories

ProductSpecifications

Product Iconswith dimensionsfor productsavailable in yourregion/state

Colour andAvailabilityinformationfor productsdistributedin yourregion/state

Boral Masonry Product Range

Boral Masonry offers a comprehensive range of proven

products and systems including Segmental Block Retaining

Wall Systems, Segmental Paving Products, Masonry Blocks,

Masonry Bricks, Masonry Fire and Acoustic Wall Systems.

What’s in this Guide

The Boral Masonry Segmental Block Retaining WallsGuide, (this book), details a comprehensive selection of

retaining wall options ranging from low height gravity

landscaping walls to critically loaded reinforced-soil retaining

structures.

This guide has been prepared as a comprehensive Boral

Product Reference Guide. It does not attempt to cover all the

requirements of the Codes and Standards which apply to

retaining wall construction. All structural detailing should

be checked and approved by a structural engineer before

construction. Boral reserves the right to change the contents

of this guide without notice.

Please note that this guide is based on products available at

the time of publication from Boral Masonry Victorian sales

region. Different products and specifications may apply to

Boral products sourced from other regions.

Additional Assistance & Information

• Contact Details: Please refer to the outside back cover of

this publication for Boral Masonry contact details.

• Colour and Texture Variation: The supply of raw

materials can vary over time. In addition, variation can

occur between product types and production batches. Also

please recognise that the printed colours in this brochure

are only a guide. Please, always ask to see a sample of

your colour/texture choice before specifying or ordering.

• Terms and Conditions of Sale: For a full set of Terms

and Conditions of Sale please contact your nearest Boral

Masonry sales office.

E4 July 2005 | BORAL MASONRY DESIGN GUIDE

Victoria Book 4 E

INTRODUCTION

Boral Keystone is an advanced,

highly versatile and thoroughly

proven high performance segmental

block retaining wall system which

can be used as a gravity structure

or it can incorporate geogrid soil-

reinforcement to cater for greater

heights and surcharge loading

situations.

DESIGN CONSIDERATIONS

• Suitable for straight and curved

wall installations with a minimum

convex curve radius of 1800mm

without trimming the tail width,

or 970mm radius by trimming the

tail to 300mm width.

• Can be installed as near vertical,

or for straightwalls without curves

or corners it can be installed with

a 1-in-8 setback.

COLOURS

Keystone is offered in a range of

colours to suit decorative and

engineering applications. Please

refer to colour swatch information

for an indication of current colours.

To reduce the possibility of staining

and to enable easier cleaning, a

masonry sealer can be applied to all

visible surfaces after installation.

Keystone®

Retaining Wall Systems

305

200

455

Standard Straight Sided Cap

275

100

455Flushface Straight Sided Cap

275

100

455

PinsLifting Bars

Description Wt kg Nº/m2

Standard Unit 35 11

Standard Straight Sided Cap 25 2.2/lin mtr

Flushface Unit 38 11

Flushface Straight Sided Cap 26.3 2.2/lin mtr

Pins 2 pins per full unit

(high strength pultruded fibreglass)

Lifting Bars (Keystone units should be lifted by

two people using the Keystone lifting bars)

Specifications

Standard Unit

305

200

455

Flushface Unit

Availability & Colours• No minimum order quantities apply.

• Lead time 0-4 weeks.

Bluestone Brown

Sunset Terracotta

Natural Parchment

Charcoal


B PLANNING AND DESIGN

Masonry Design Guide

4B44BORAL MASONRY


B2

Victoria Book 4 B

July 2005 | BORAL MASONRY DESIGN GUIDE

An Introduction to Segmental

Block Retaining Walls

Background

For many years cantilever retaining walls have been

constructed with reinforced concrete masonry stems (steel

reinforcement grouted into hollow concrete block work) and

reinforced concrete footings. (Refer to Fig B1).

Segmental block gravity retaining structures, consisting of

dry-stacked concrete units which resist overturning byvirtue

of their own weight and setback,were introduced into Australia

in the early 1990’s, and rapidly became popular. This system

provides an attractive and cost effective solution, but its

stability is limited by the geometry of the units and wall

heights. (Refer to Fig B2).

In order to achieve greater heights, reinforced-soil walls (such

as Boral Keystone) were introduced. These walls typically

consist of geosynthetic materials, which are placed in

horizontal layers in the compacted backfill and mechanically

connected to the blocks. Such systems can be constructed

several metres high, and accommodate significant loads.

A further development of this system is the Boral Keysteel

system which utilises steel-ladder reinforcement. Here the

steel-ladder reinforcement is placed in horizontal layers in the

compacted backfill and mechanically connected to the blocks.

These systems are individually engineer designed, and are

suitable for walls in excess of 6m high and for critical

surcharge loadings. (Refer to Fig B3).

Steel reinforced and concrete grout filled hollow concrete block wall

Reinforced concrete footings

Fig B1 – Typical Reinforced Concrete MasonryCantilever Retaining Wall

Segmental block gravity retaining structure, dry-stacked against a soil slope

Fig B2 – Typical Segmental Block Gravity Retaining Wall

Segmental concrete gravity retaining structure, with reinforced soil

Fig B3 – Typical Reinforced-Soil Segmental Block Retaining Wall

B3

Victoria Book 4 B

BORAL MASONRY DESIGN GUIDE | July 2005

Behaviour of Segmental Block

Reinforced-Soil Retaining Walls

If unrestrained, a soil embankment will slump to its angle

of repose. Some soils, such as clays, have cohesion that enables

vertical and near-vertical faces to remain partially intact, but

even these may slump under the softening influence of ground

water. When an earth retaining structure is constructed, it

restricts this slumping. The soil exerts an active pressure on

the structure, which deflects a little and is then restrained

by the friction and adhesion between the base and soil

beneath, passive soil pressures in front of the structure and

bearing capacity of the soil beneath the toe of the structure.

If water is trapped behind the retaining structure, it exerts

an additional hydraulic pressure. This ground water also

reduces the adhesion and bearing resistance.

If massive rock formations are present immediately behind

the structure, these will restrict the volume of soil which can

be mobilised and thus reduce the pressure.

Reinforced-soil systems consist of a series of horizontal

geogrids that have been positioned and pulled tight within

a compacted soil mass, thus strengthening it and restricting

its slump. The geogrids are strategically placed to intersect

potential failure planes that are inclined from near the base

of the wall, up at an angle (depending on the soil properties),

to the top of the fill. The function of the geogrids is to

‘strengthen’ the soil mass and they are ‘anchored’ by compacted

backfill beyond the potential failure planes.

Local collapse and erosion of the front face is eliminated by

fixing concrete segmental facing units to the exposed ends

of the geogrids. However, the segmental concrete facing is

not designed to ‘retain’ the strengthened soil mass, which

should be able to stand independently of the facing except

for local effects. The connection spacing (and the geogrid

spacing) must account for the local stability of the facing,

including bulging and rotation above the top geogrid. The

top capping course is normally bonded to the course below

using a concrete to concrete adhesive.

A surface sealing layer and surface drainage system minimise

the quantity of rainwater entering the soil mass. A sub-surface

drainage system behind the segmental concrete facing and

(sometimes) beneath the wall reduce pore water pressures

and thus reduce the tendency for local or global slip.

Thus, the essential features of a properly designed and

constructed segmental block reinforced soil retaining wall are:

• Geogrids with adequate length and strength;

• Adequate connection to the facing to provide local stability;

• A drainage system that will relieve hydro static pressures

for the life of the structure.

Importance of a Geotechnical Report

The design of a reinforced soil retaining wall includes two

essential parts:

• Analysis of the proposed reinforced soil structure and the

adjacent ground for global slip, settlement, drainage and

similar global considerations; and

• Analysis and design of the reinforced soil structure itself.

These analyses must be based on an accurate and complete

knowledge of the soil properties, slope stability, potential slip

problems and ground water.

Except in the case of simple structures, a geotechnical report

by a qualified and experienced geotechnical engineer should

be obtained.

Such a report must address the following considerations, as

well as any other pertinent points not listed.

• Soil properties;

• Extent and quality of any rock, including floaters and

bedrock;

• Global slip and other stability problems;

• Bedding plane slope, particularly if they slope towards

the cut;

• Effect of prolonged wet weather and the consequence of

the excavation remaining open for extended periods;

• Effect of ground water;

• Steep back slopes and the effect of terracing;

• Effect of any structures founded within zone of influence.

Safety and Protection of Existing

Structures

Whenever soil is excavated or embankments are constructed,

there is a danger of collapse. This may occur through

movement of the soil and any associated structures by:

• Rotation around an external failure plane that encompasses

the structure;

• Slipping down an inclined plane;

• Sliding forward, or

• Local bearing failure or settlement.

B4

Victoria Book 4 B


These problems may be exacerbated by the intrusion of surface

water or disruption of the water table, which increase pore

water pressures and thus diminish the soil’s ability to stand

without collapse.

The safety of workers and protection of existing structures

during construction must be of prime concern and should

be considered by both designers and installers. All excavations

should be carried out in a safe manner and in accordance

with the relevant regulations, to prevent collapse that may

endanger life or property. Adjacent structures must be founded

either beyond or below the zone of influence of the excavation.

Where there is risk of global slip, for example around a slip

plane encompassing the proposed retaining wall or other

structures, or where there is risk of inundation by ground

water or surface water, construction should not proceed until

the advice of a qualified and experienced Geotechnical

Engineer has been obtained and remedial action has been

carried out.

Global slip failure

Soil retaining structures must be checked for global slip

failure around all potential slip surfaces or circles.

Designers often reduce the heights of retaining walls by

splitting a single wall into two (or more) walls, thus terracing

the site. Whilst this may assist in the design of the individual

walls, it will not necessarily reduce the tendency for global

slip failure around surfaces encompassing all or some of the

retaining walls.

Analysis for global slip is not included in this guide, but it is

recommended that designers carry out a separate check using

commercially available software.

Differential Settlement

The Concrete Masonry Association of Australia (CMAA)

recommends that for dry stacked mortarless retaining walls

employing masonry units (i.e. units with an area less than

0.2m2) on an aggregate levelling pad, the differential

settlement should be limited to 1% of the length. Whilst it is

permissible for the retaining wall to undergo differential

settlement up to 1% of the length, it may be preferable to limit

settlement to a lower figure giving consideration to aesthetics

(i.e. keeping the bedding planes level), in addition to the

structural considerations.

Techniques to reduce or control the effects of differential

settlement include:

• Articulation of the wall (in discontinuing the normal

stretcher bond) at convenient intervals along the length,

or

• Excavating, replacing and compacting areas of soft soil,

• Limiting the stepping of the foundation and bottom course

to a maximum of 200mm.

Unit Cracking/Gapping – Settlement

Keystone modular retaining wall structures can tolerate a

certain amount of settlement due to the flexible nature of the

system and small individual unit size.

Observation of a number of completed structures that have

undergone settlement indicates that the wall’s tolerance for

settlement without cracking is inversely proportional to the

wall height. Lower height walls (H<5m) appear to have

considerably more facial flexibility than taller walls (H>5m).

This increased flexibility is due to lower confining forces and

load transfer taking place on each block,which permits small

individual movements to occur, accommodating the settlement

experienced without facial distress. Taller walls place the

lower wall units under considerable confining pressure,

restricting unit movement and permitting shear and flexural

stresses to build up to the point where a block cracks as a

means of stress relief.

Low wall settlement problems are typically observed in

residential projects where soils adjacent to houses are

uncompacted and the walls settle differentially over a short

distance. Usually gapping or offset joints are visually noted

and the settlement is obvious.

Gapping and offset joints

Downward movement

Fig B4 – Typical Low WallSettlement

B5

Victoria Book 4 B


Tall wall settlement is not as obvious but occasional facial

cracks can be observed in areas of f lexural stress

concentration, typically in small groupings in the bottom 1/3

of the wall. Settlement induced cracks are usually not

structurally significant and are just a means of facial stress

relief for the unreinforced dry-stack facing system. However,

cracked units can be a symptom of other types of problems,

so a review by an engineer is always recommended.

Importance of Drainage

This guide assumes that a properly functioning drainage

system is effective in removing hydraulic pressure. If this is

not the case, the designer will be required to design for an

appropriate hydraulic load.

Based on an effective drainage system, it is common to use

drained soil properties. For other situations, the designer

must determine whether drained or undrained properties are

appropriate. In particular, seawalls that may be subject to

rapid drawdown (not covered in this guide) require design

using undrained soil properties.

High confining pressure

Flexural stress

Facial cracks

Downward movement

Fig B5 – Typical Tall WallSettlement

B6

Victoria Book 4 B


B B4 k 4 ok ookBo Ba oriatorctoVicV

Site Investigation: Preliminary Design

Date: ____________________

Report prepared by: ____________________

Client: ______________________________________________________________________

Project: ______________________________________________________________________

Location: ____________________________________________________________________

Use for which retaining wall is intended: __________________________________________

Proximity of other structures to the face of the retaining wall:

Structure or load Distance (m)

Distance of live loads from top of wall (Dqi) ____________________

Distance of dead loads from top of wall (Dqd) ____________________

Distance of point loads from top of wall (Di) ____________________

Distance of other structures from base of wall (Ds) ____________________

Structure classification: __________________________________________________

For guidance refer AS4678, Table 1.1

Structure Classification Examples

2. Where failure would result in significant damage or risk to life

3. Where failure would result in moderate damage and loss of services

4. Where failure would result in minimal damage and loss of access

Required design life:______________________________________________________

For guidance refer AS4678, Table 3.1

Type of Structure Design life (years) Type of Structure Design life (years)

Temporary site works 5 Residential dwellings 60

Mine structures 10 Minor public works 90

Industrial structures 30 Major public works 120

River and marine structures 60

Wall geometry:

Wall height above GL (H’) __________ m

Embedment depth (Hemb)

H/20 or 200mm __________ m

Wall slope (�) __________ °

Angle of backfill slope (�) __________ °

Height of backfill (h) __________ m

Foundation material:

Allowable bearing pressure

Under reinforced soil block __________ kPa

Water profile:

Water table depth within wall fill __________m

Retained soil data:

Soil density (�r) __________ kN/m3

Internal friction angle (�r) peak __________ °

Cohesion (C*i) __________ kPa

Loading data:

Dead load surcharge (qd) __________kPa

Live load surcharge (ql) __________kPa

Horizontal line load (F) __________kN/m

Vertical line load (P) __________ m

Width of bearing (b) __________ m


C GARDENWALL®

4C44Masonry Design Guide

BORAL MASONRY


C2

Victoria Book 4 C


INTRODUCTION

Boral Gardenwall is ideal for low

landscaping walls and edgings in

garden and communal areas.

Gardenwall’s rockface texture, multi-

faceted face and setback construction

produces an aesthetically pleasing

feature for landscaped areas.

Gardenwall is often used for garden

edges and raised beds, terraces and

to create decorative features such

as around pools.


Depending on the foundation and

retained soil characteristics,

Gardenwall is effective as a gravity

retaining wall structure up to

1125mm (maximum 9 courses).

Never install where loads (e.g.

buildings, driveways) will be located

within 1125mm of the wall. For

engineered walls (to AS4678) higher

than 1125mm, orwhere a surcharge

is present, Boral Keystone or

Pyrmontwalls should be considered.

ADVANTAGES

• Gardenwall does not require

concrete foundations.

• Easy installation of straight walls

and curved walls.

• Durable, low maintenance, long-

term landscaping.

• Solid units – eliminates the need

for capping and corner units.

COLOURS

Gardenwall is offered in a range of

colours to suit traditional and

contemporary settings. Please refer

to colour swatch information for an

indication of current colours.





Product Description Finish HxLxDmm Approx Wt kg Nº/m2

Standard Unit Rockfaced 125x305x228 16.5 26.3 units/m2

Specifications

Gardenwall®

Retaining Wall System

228

125

305



Standard Unit

Portstone

TerrainLight Sands

Kota Green

Hawkesbury YellowPaperbark

C3

Victoria Book 4 C


IMPORTANT: Please consult with the regulating council for

local design requirements prior to the design and construction

of a retaining wall. Councils in general require that retaining

walls be designed and certified by a suitably qualified engineer

where the wall is over 0.5m in height and/or where there is

surcharge loading such as a roadway, house, or other structure

near the wall.

• Boral Gardenwall is only suitable for walls up to 1125mm

in height and where no loads or surcharge exists within

1125mm behind the wall.

Installation

• Remove the retaining lug on the base of the unit on those

Gardenwall blocks being used on the base course only

(this makes levelling the first course much easier).

To remove the lip, place at an angle on the ground and strike

the lug firmly with a hammer (safety glasses should

be worn).

• As a safety precaution to avoid lifting or movement of the

top units, it is recommended that the top course units are

secured using a construction adhesive. This is also

recommended in areas of possible vandalism.

• Standard units can also be used to construct convex curves.

Gardenwall Unit

1 in 5 set-back

150mm width of 12-20mmØ free draining granular material eg. blue metal

Backfill placed and compacted in 250mm layers

Compacted road base levelling pad on undisturbed inorganic soil

First course to be buried below final ground level (to engineer's specification - 100mm min.)

Drainage pipe (if required)

350mmmin.

100mm min.

Native soil

Dish drain to direct surface run-off (if required)

H

No loads to be located within 1125mm behind wall

Backfill should be no higher than the top of the wall

Fig C1 – Typical Gravity Wall Construction Detail – Gardenwall

Selection & Construction Guidelines

Note: Refer to max. wall heights disclaimer on page A3 of this guide.

The gravity wall heights are maximum heights calculated in accordance with CMAA MA-53 Appendix D guidelines and a qualified engineer should confirm

the suitability of the product for each intended application.

C4

Victoria Book 4 C


for 1st course

Radius = 1000mm

Minimum

Fig C2 – Construction of Curved Walls

• When designing Gardenwall for convex curves to the

maximum height of 8 courses, it is necessary to begin

with a minimum radius of 1000mm. It may also be

necessary to remove the outer portions of the retaining lug

from each unit to maintain a consistent setback. It is

important that the entire lug is not removed.

• When building curves, some blocks may also require

trimming of the length to maintain a half bond pattern.

Curved Walls


D HEATHSTONE®

4D44Masonry Design Guide

BORAL MASONRY


D2

Victoria Book 4 D


INTRODUCTION

Boral Heathstone is ideal for low,

vertical landscaping walls in garden

and communal areas. The rockface

texture and bevelled edges add a

formal and elegant element to a

landscaped area. Heathstone is often

used to separate and highlight

entertaining areas, BBQ areas, paths,

garden beds, hedges, or to create and

differentiate levels. Heathstone is

also suitable for constructing steps,

planter boxes and for curved walls.


Depending on the foundation and

retained soil characteristics,

Heathstone is effective as a gravity

structure up to 972mm, or up to

1600mm when installed with no-

fines concrete backfill. Heathstone

should not be used where the base

soil or backfill is not firm, or is of

expansive clay. Never install where

loads (e.g. buildings, driveways) will

be located within 1000mm of the

wall. For walls higher than this, or

where a surcharge is present, Boral

Keystone or Pyrmont walls should

be considered.

The range of Heathstone components

is designed to optimise space, and

includes a ready-to-install corner

unit and a series of caps to

accommodate single or double sided

applications and curved installations.

Convex curves as tight as 900mm

radius can be constructed using the

standard unit. The Curved Cap can

be used to form curves of 1800mm

outside radius and 1500mm inside

radius.

COLOURS

Heathstone is offered in colours

which emulate natural hewn stone,

and which contrast beautifully with

soil, mulch, shrubbery and grassed

areas. Please refer to colour swatch

information for an indication of

current colours.





Product Description Finish HxLxDmm Approx Wt kg Nº/m2

Standard Unit Rockfaced 162x220x280 11.0 28.1 units/m2

Standard Corner Unit Rockfaced x 2 Faces 162x380x270 15.6 1/course/corner

Grand Unit Rockfaced 162x440x280 26.3 14.05 units/m2

Grand Corner Unit Rockfaced x 2 Faces 162x380x160 10.5 1/course/corner

Splitface Cap Rockfaced x 1 Edge (225mm) 60x225x340 11.3 4.5/linear metre

Double Sided Rockface Cap Rockfaced x 2 Long Edges 50x600x300 22.0 1.6/linear metre

Rockface Corner Cap Rockfaced x 2 Adjacent Edges 50x300x300 10.7 1/corner

Double Sided Rockface Rockfaced x 2 Long Edges 50x392/470x300 15.6 24 per Full Circle (15° each)

Curved Cap 6 per Quarter Circle

Heathstone®

Retaining Wall System

280

162

220

Grand Unit

280

162

440

Grand Corner Unit

380

162

160

380

162

270

300

50

300

RockfaceCorner Cap

1800radius

392

300

470

50

Double Sided RockfaceCurved Cap

Specifications



Hawkesbury Yellow

Charcoal

Portstone

340

60

225

Splitface Cap

Standard Unit Standard Corner Unit

300

50

600

Double Sided Rockface Cap

Note: Refer to max. wall heights disclaimer on page A3 of this guide.

D3

Victoria Book 4 D


Maximum Courses Maximum Courses

For walls without gravel fills For walls with gravel fills

to all voids and cores to all voids and cores

Poor soils – including sands, gravelly

clays, sandy clays and silt clays 2 (324mm) 4 (648mm)

Average soils – including well graded

sands and gravelly sands 3 (486mm) 5 (810mm)

Good soils – including gravels, sandy

gravels and crushed sandstone 4 (648mm) 5 (810mm)

NOTES: Backfill retained by a retaining wall should be no higher than the top of the retaining wall.

For engineered retaining walls to AS4678, refer to the Heathstone No-Fines Concrete Wall Guidelines.

Refer to max. wall heights disclaimer on page A3 of this guide.

The gravity wall heights are maximum heights calculated in accordance with CMAA MA-53 Appendix D guidelines

and a qualified engineer should confirm the suitability of the product for each intended application.

Blocks to be embedded a minimum of 100mm

Native soil

No loads to be located within 1.0m of the wall

150mm min. of 12-20mmØ free draining granular material eg. blue metal

Dish drain to direct surface water or filter fabric to stop silt filling drainage layer

Voids in and around Heathstone blocks to be filled (if required) with 12-20mmØ free draining granular material eg. blue metal

Backfill (eg. excavated soil) to be placed and compacted as each course of blocks is laid

Agricultural drainage line 100mmØ

100mm min.

350mm min.

Refer to Heathstone Gravel-Fill Selection Table for maximum number of courses

Compacted roadbase

Fig D1 – Typical Construction Detail – Heathstone Gravel-Fill

IMPORTANT: Please consult with the

regulating council for local design

requirements prior to the design and

construction of a retaining wall. Councils

in general require that retaining walls be

designed and certified by a suitably

qualified engineer where the wall is over

0.5m in height and/or where there is

surcharge loading such as a roadway,

house, or other structure near the wall.

Heathstone® Gravel-Fill Construction

Table D1 - Maximum Wall Height – Heathstone Gravel-Fill

D4

Victoria Book 4 D


Curved Wall Construction

Curves as small as 900mm in radius can be constructed

with Heathstone Standard Units.

NOTE: Double Sided Rockface Curved Cap radius is 1500mm

to the inside face and 1800mm to the outside face.

Bolster back of blocks to form convex curves

NOTE: Premium Curved Caps have an outside radius of 1800mm

Fig D3 – Forming Convex Curve

1800mm

1500mm Heathstone Curved Cap

Fig D2 – Heathstone Curved Cap Radius

Concave (Internal) Curves

• For concave curves use Standard Units spaced evenly to

a scribed arc in conjunction with Double Sided Rockface

Curved Caps butted together to form a 1500mm radius

wall face.

Concave Curve Radius

Heathstone Standard Unit

NOTE: Premium Curved Caps have an inside radius of 1500mm

Fig D4 – Forming Concave Curve

1:10 Cement : Sand

Native soil

255

162

45

25

Heathstone Units

Remove locating lugs before laying

Fix cap units with construction adhesive

Double Sided Rockface Cap

Fig D5 – Construction of Heathstone Steps

Note: For alternative step detail, see page E10.

Convex (External) Curves

• For convex curves, the tails of the blocks must be trimmed

to suit the desired radius. Use a hammer and bolster on

the back, top and bottom of the tail. Use light hammer

blows first to trace the area to be removed, then a heavier

blow on top. Repeat the tracing and final blow if necessary.

Step Construction

D5

Victoria Book 4 D


Step Treads and Cap Unit Installation

• Splitface Cap (225mm long) has a recess in the underside

to allow for the lug on the Heathstone Unit. Removal of the

lug is not required in this case

• To allow for installation of the Double-sided Rockface Cap

units and step treads, it is necessary to bolster locating

lugs from the blocks.

• Push the Heathstone split-face into sand for support. Trace

along the back of the lug with a bolster and hammer,

increasing the force of hammer blows until the lug splits

off. All blows must be from the back of the block, with the

bolster blade nearly parallel to the top of the Heathstone

unit. Refer to the illustration. Any remaining high spots

should be removed with a scutch hammer or an old

screwdriver and hammer.

Fig D6 – Bolstering Lug from Heathstone Units

D6

Victoria Book 4 D


Corner UnitCorner Unit

Fig D7 – Heathstone External Corner (270°)

Corner Unit

Standard Unit

Corner Unit

110mm

Fig D8 – Heathstone Internal Corner (90°)

Grand Corner Unit

Grand Unit

Grand UnitBolster lug to fit next course

Fig D9 – Heathstone Grand External Corner (270°)

Grand Unit

Grand Unit

Bolster lug tofit next course

Bolster lug tofit next course

220mm

NOTE: Internal 90º corners using Grand Units do not require corner units

Fig D10 – Heathstone Grand Internal Corner (90°)

Corner Construction

Constructing Internal and External Corners

• Corners are constructed using Corner Units and Standard

Units or Grand Units and Grand Corner Units.

• Lay the Corner Units’ largest splitface in alternate directions

in adjacent courses (see illustrations).

• Continue this step until the desired height of the wall is

achieved.

• Use a construction adhesive to secure corner blocks and

caps.

D7

Victoria Book 4 D


No-Fines Concrete shall consist of cement, water and coarse

aggregate. Cement will complywith the definitions for cement

per AS3972-1991 – ‘Portland and Blended Cements’. The

quantity of cement is specified as 210kg/m3 with a total

water/cement ratio of between 0.45 and 0.55.

The particle size distribution of the aggregate shall comply

with the limitations for the nominal single sized 20mm

aggregate specified in AS2758.1.

NOTES:

• Table D2 is based on AS4678 : 2002, Earth Retaining

Structures. The code assumes a surcharge of 5kPa is

Wall Height Retained Soil Retained Soil Retained Soil

‘H’ (mm) CLAY � = 26° (POOR) SAND � = 30° (AVERAGE) GRAVEL � = 34° (GOOD)

‘T’ (mm) ‘T’ (mm) ‘T’ (mm)

972 670 570 570

1296 730 770 670

1620 1170 970 770

� Denotes the internal angle of friction of the retained material

H (Refer to Heathstone

No-Fines ConcreteSelection Table)

Blocks to be embedded to engineer‘s detail (1 course min.)

Retained soil

No loads above 5kPa to be located within 1.0m of the wall

T

25MPa concrete footing on 150kPa allowable bearing capacity material

15MPa ‘No Fines’ concrete.All voids within and around units to be completely filled.

Filter fabric or dish drain

Cap unit

Pour no-fines concrete directly onto prepared foundation material

Sub-soil drain connected to stormwater system or flood pit. Place loose aggregate around subsoil drain before pouring no-fines concrete.

150mm min.

600mm min.

Fig D10 – Typical Construction Detail – Heathstone No-Fines Concrete Wall

Heathstone® No-Fines Concrete Wall Construction

Table D2 – Heathstone Maximum Wall Heights – No-Fines Concrete Construction

applied to all retaining wall structures.

• Global stability and all design considerations should be

checked by an engineer in poor clay conditions.

• Design assumes a dry excavation (i.e. water table is below

bottom of footing level). If ground water exists in the

excavation the wall is to be re-designed by a suitably

qualified engineer.

• These tables are supplied free of charge and do not form

any part of any contract with the user.

• 15MPa No-Fines concrete with a 6:1 ratio (Gravel : Cement).

D8

Victoria Book 4 D


• The density of this product will vary with the density of

the aggregate used. The density range may be from

1650kg/m3 to 2100kg/m3.

• The void ratio of the mix is expected to be between 20%

and 30% and should be free draining.

• The compressive strength should generally exceed 15MPa

for design purposes.

• This product has no slump and exerts similar pressures

on the soil and formwork, as does loosely poured aggregate.

No-Fines Construction Steps

Special purpose construction such as waterside walls, post

fixing, earthquake zones, and terraces will require additional

engineer’s design.

STEP 1: Excavation/Preparation of Levelling Pad

Excavate a trench 600mm wide and sufficiently deep to allow

a 150mm levelling base plus 1 course below ground.

STEP 2: Installing the First Course

Lay the first course of Heathstone units side by side over the

prepared base. Bolster off the tails so that ‘No-Fines’ concrete

connects backfill to core-fill areas.

STEP 3:No-Fines Concrete Backfill

Backfill the first 21⁄2 courses of the wall with ‘No Fines’ concrete.

All voids inside and between the units must also be filled. The

vertical height of any pour of ‘No Fines’ concrete is limited

to 400mm. For walls greater in height, each pour must be

allowed to harden prior to pouring the next lift. Alternatively

the wall may be propped to support the lateral load from the

wet concrete.

STEP 4:

Installing Capping Units

Install capping units and fix with construction adhesive.


E KEYSTONE® AND PYRMONT®

4E44Masonry Design Guide

BORAL MASONRY



Victoria Book 4 E

Keystone® & Pyrmont Retaining Wall Systems

The Keystone Retaining Wall System is a world-widesuccess story, and since its introduction by Boral intoAustralia in 1992, hundreds of thousands of square metreshave been installed along our highways, roads andtransport corridors, and around our sports facilities,buildings, foreshores and open spaces.

Boral Keystone retaining wall systems combine provenengineering capabilities with design versatility, costeffectiveness, lasting durability and an attractive dynamicappearance to provide total solutions for retained earthstructures.

Keystone®

Boral Keystone systems provide infinite flexibility fordesign variation and individuality. The range of componentsand installation methods cater for straight, curved andterraced walls, level or stepped foundations and capping,

and a near vertical or set-back face. Then there is a choiceof standard or flushface, and a selection of popularstandard colours or custom colours can be ordered forlarger projects.

Pyrmont®

Boral Pyrmont retaining wall system retains all of theengineering characteristics of the Keystone system andcombines them with a more traditional appeal of abevelled-edge splitface block, and vertical constructionto emulate walls built during Australia’s pioneering era.

The range of components and installation methods caterfor straight and gently curved walls as well as crisp90º corners, while the rock-faced caps provide a finishingtouch that completes the transformation into amasterpiece from the colonial era.

E3BORAL MASONRY DESIGN GUIDE | July 2005

Victoria Book 4 E

Ease of Construction

Boral Keystone and Pyrmont systems are designed toreduce construction time and cater for all locations. Themodular blocks can be moved and installed without theneed for heavy lifting machinery, and the dry stacked,mortarless installation provides less complex, more rapidconstruction.

Proven Engineering

Various installation methods cater for simple gravity wallsthrough to geogrid soil-reinforced retaining structures. BoralKeystone and Pyrmont systems can also cater for criticalsurcharge loads, enabling the construction of buildings orroadways close to the wall to optimise land usage.

For high performance retaining walls, please refer to thesection on Boral Keysteel Custom Engineered RetainingWall Systems later in this guide.

Durability

Boral Keystone and Pyrmont systems combine thedurability of concrete units and interlocking fibreglasspins to produce maintenance free walls with lifeexpectancies of up to 120 years.


Victoria Book 4 E

INTRODUCTION

Boral Keystone is an advanced,

highly versatile and thoroughly

proven high performance segmental

block retaining wall system which

can be used as a gravity structure

or it can incorporate geogrid soil-

reinforcement to cater for greater

heights and surcharge loading

situations.


• Suitable for straight and curved

wall installations with a minimum

convex curve radius of 1800mm

without trimming the tail width,

or 970mm radius by trimming the

tail to 300mm width.

• Can be installed as near vertical,

or for straightwalls without curves

or corners it can be installed with

a 1-in-8 setback.

COLOURS

Keystone is offered in a range of

colours to suit decorative and

engineering applications. Please

refer to colour swatch information

for an indication of current colours.





Keystone®


305

200

455


275

100

455Flushface Straight Sided Cap

275

100

455

PinsLifting Bars


Standard Unit 35 11






Lifting Bars (Keystone units should be lifted by


Specifications

Standard Unit

305

200

455

Flushface Unit



Bluestone Brown

Sunset Terracotta

Natural Parchment

Charcoal


Victoria Book 4 E

Lifting Bars

INTRODUCTION

Boral Pyrmont retaining wall

systems integrate the engineering

capabilities of the Keystone system

with the versatility and pleasing

aesthetics of a vertical wall. The

Pyrmont unit is a split-face block

with four chamfered edges,

emulating the care, skill and

determination of stone masons from

Australia’s early settler period.

Boral Pyrmont retaining wall system

is also suitable for constructing

steps, planter boxes, gently curved

walls and crisp 90° corners.


Suitable for curved wall installations

with a suggested minimum convex

curve radius of 5m (resulting in

a 5mm lip).

COLOURS

Please refer to colour swatch


current colours.





222 222

200

450 450

Premium Cap Rockfaced(Hawkesbury Yellow only)

355

65

455

Premium Corner CapRockfaced(Hawkesbury Yellow only)

355

65

355


Standard Unit 37.3 11

Standard Cap (Rockfaced 1 side) 11.3 4.44/lin mtr

Premium Cap (Rockfaced 1 side) 24 2.2/lin mtr

Premium Corner Cap (Rockfaced 2 sides) 18.8 1/90° corner

90° Corner Unit (Right or Left Hand) 31 5/vertical metre



Lifting Bars (Pyrmont units should be lifted by


Specifications

Pyrmont®

Vertical Retaining Wall System

305

200

455

Standard Unit

340

60

225

Standard Cap



Hawkesbury YellowPortstone

Charcoal

90° Corner UnitRight or Left Hand

Pins


Victoria Book 4 E

226mm pin cts 226mm pin cts

Fig E1 – Installation of Pins

IMPORTANT: Please consultwith the regulating council forlocal

design requirements prior to the design and construction of a

retaining wall. Councils in general require that retaining walls be

designed and certified by a suitably qualified engineerwhere the

wall is over0.5m in heightand/orwhere there is surcharge loading

such as a roadway, house, or other structure near the wall.

Refer to Keystone and Pyrmont ‘No-Fines Concrete’ Guidelines

for engineered retaining walls to AS4678.

• Two sets of pin holes are provided in Keystone units.

• For near vertical construction, install pins in the front

holes, and maintain a distance of 226mm between pin

hole centres of adjacent units.

• For 1 in 8 setback construction, install pins in the back

holes, and maintain a distance of 226mm between pin

hole centres of adjacent units.

• Near vertical installation must be used when designing

walls with curves or corners.

Wall Height H (mm)

Surcharge LoadingBackfill

Near 1 in 8Type

Vertical Setback

SETBACK Poor 800 900

Average 900 1000

Good 1000 1200

Poor 600 900

Average 700 900

Good 800 1100

Poor 400 500

Average 500 600

Good 600 800

No

Su

rch

arge

Lo

adin

g15

°S

lop

ed B

ackf

illD

rivew

ay/C

arpa

rk L

oadi

ng (5

kPa)

Table E1 – Maximum Wall Height for Gravel-Fill WallsGravel-Fill Wall Selection

Gravel-Fill Wall Construction Guidelines

For low, non-critical walls, (i.e. walls covered in the adjacent

table) the Keystone and Pyrmont Retaining Wall Systems are

effective as a gravity wall structure, utilising their weight

and interaction of the units to resist earth pressures.

Retained Soil Descriptions

Poor Soils Include fine sands, gravelly

clays, sandy clays, silty sands.

Angle of internal friction ≥ 25°

Average Soils Include well graded sands,

gravelly sands.


Good Soils Include gravels, sandy gravels,

crushed sandstone


NOTES: Pyrmont walls can only be constructed in near

vertical format, and must be selected on the basis of data in

the near vertical column from Table E1.

Table E1: Refer to max. wall heights disclaimer on page A3 ofthis guide. The gravity wall heights are maximum heights

calculated in accordance with CMAA MA-53 Appendix D

guidelines and a qualified engineer should confirm the

suitability of the product for each intended application.


Victoria Book 4 E

• For curved installations, maintain 226mm between pin

hole centres of adjacent units. This will leave a small gap

between units for convex curves, and will require a small

overlap of adjacent units with concave curves. Refer to

curve installation details on Page E9 of this guide.

• If backfill is required behind the drainage zone, place and

compact existing site soils in 200mm maximum lifts.

Heavy clays and organic soils are not recommended due

to water holding problems.

• Provide a filter fabric between drainage layer and backfill

if the type of backfill is likely to wash into drainage layer

and clog it.

• Use only walk-behind compaction equipment within

1000mm of the wall face to prevent movement of the

Keystone units.

• In areas of possible vandalism, it is recommended that

capping units be secured using a masonry adhesive.

Fig E2 – Typical Installation Detail – Keystone Gravity Wall

Native soilCompacted footing

Free draining granular material

Drainage pipe

Compacted backfill soil (if required)

Cap Unit

Keystone or Pyrmont units

Optional 1:8 wall setback with Keystone units

12-20mm free draining granular material, fill all voids in and around units

Compacted roadbase, crushed stone or gravel levelling pad

First course to be buried below final ground level (to engineer's specification - 100mm min.)

Drainage pipe (if required)

300mm

Granular material for drainage

600mm min.

150mm min

H

Backfill

Fig E3 – Typical Construction Detail – Keystone Gravity Wall


Victoria Book 4 E

FIRST COURSE SECOND COURSE

Align centre of unit with face of adjoining wall

No pin in overlapping unit

No pin in overlapping unit

Align face of unit with thecentre line of adjacent unit


Align face of unit with thecentre line of adjacent unit

Omit one pin only

Cut to suit on site

Omit one pin only

Cut to suit on site

Fig E4 – 90° Internal Corner – Standard Keystone Units

Fig E5 – 90° Internal Corner – Flushface Keystone/Pyrmont Units

455mm305mm

77mm

455mm

455mm

455mm

90˚ corner unit cut from face of Flushface unit and fixed in place with epoxy adhesive

Use Flushface unit and bolster face to suit


Omit one pin only

Fig E6 – 90° External Corner with Standard Keystone Units

Typical Installation Details


Victoria Book 4 E

Use front pin holes for curves. Maintain a centre-to-centre distance of 226mm between pins in adjacent units (small overlaps between units will be required)

226mm centres

Fig E8 – Concave Curve

Pyrmont corner unit

Pyrmont corner unit

455mm450mm

222mm

455mm

455mm

455mm


Fig E7 – 90° External CornerPyrmont Units

Rad

ius

‘r’

226mm

3 unit 90 corner : r = 900mm





Use front pin holes for curves. Maintain a centre-to-centre distance of 226mm between pins in adjacent units (small gaps between units will be required)

Bolster backs as required

Fig E9 – Convex Curve


Victoria Book 4 E

Keystone cap unit

Keystone unit

Bedding sand –compact before laying treads

Compacted bedding sand

Sand : cement = 6 : 1

40mm Boral Pavers

10mm mortar joint

Keystone Flushface Caps

Tread approx. 290mm for 40mm pavers (30˚)

10mm

10mm100mm

40mm

160mm riser

Fig E12 – Keystone section through steps

Fig E10 – Stepped Capping Units

290mm Treads

Bolster backs as required

Fig E11 – Plan view of step through Keystone


Victoria Book 4 E

H

Blocks embedded to engineer's detail (100mm min)

Retained soil

T

25MPa concrete footing on 150kPa allowable bearing capacity material (see note below Table E2)

15MPa ‘No-Fines’ concrete.All voids within and around units to be completely filled.

Filter Fabric

Cap unit

Keystone or Pyrmont unit

Pour no-fines concrete directly onto prepared foundation material

Sub-soil drain connected to stormwater system or flood pit

150mm min

600mm min.

Fig E13 – Typical Construction Detail – Keystone No-Fines Concrete Mass Gravity Wall

‘No-Fines Concrete’ Wall Construction Guidelines

Wall Height Retained Soil Retained Soil Retained Soil

CLAY � = 26° (POOR) SAND � = 30° (AVERAGE) GRAVEL � = 34° (GOOD)

‘H’ (mm) ‘T’ (mm) ‘T’ (mm) ‘T’ (mm)

1000 550 500 450

1400 750 700 650

1800 NA 1000 850

2200 NA 1250 1000

2600 NA 1350 1200

� Denotes the internal angle of friction of the retained material

Non-shaded Area = Compacted Roadbase Footing Shaded Area = Concrete Footing as per Fig E13

If material below no-fines concrete is of poor quality, then the material must be replaced with a 150mm thick layer of crushed sandstone

The ‘No-Fines Concrete’ backfill system increases the mass

of Keystone/Pyrmont allowing the maximum heights in Table

E1 to be exceeded without using geogrids.

This is ideal for boundary walls where the geogrids would

otherwise cross the boundary line.

No-Fines Concrete shall consist of cement, water and coarse

aggregate. Cement will complywith the definitions for cement

per AS3972 : 1991 – ‘Portland and Blended Cements’. The

quantity of cement is specified as 210kg/m3 with a total

water/cement ratio of between 0.45 and 0.55.

The particle size distribution of the aggregate shall comply

with the limitations for the nominal single sized 20mm

aggregate specified in AS2758.1.

NOTES:

• 15MPa No-Fines concrete with a 6:1 ratio (Gravel : Cement).

• The density of this product will varywith the density of the

aggregate used. The density range may be from 1650kg/m3

to 2100kg/m3. (Table based on density of 2100 kg/m3.)

• The void ratio of the mix is expected to be between 20%

and 30% and should be free draining.

Table E2 – Maximum Wall Heights for No-Fines Concrete Wall Construction


Victoria Book 4 E

• The compressive strength should generally exceed 15MPa

for design purposes.

• This product has no slump and exerts similar pressures

on the soil and formwork, as does loosely poured aggregate.

Table E2 is prepared as per AS4678 : 2002, and is based

on a 5kPa surcharge loading at the top of the wall. This

table is supplied as a guide, and does not form any part

of any contract with the user.

• The maximum slope of the backfill behind the wall is to

be 5% (1 vertical to 20 horizontal).

• The vertical height of any pour of ‘No Fines’ concrete is

limited to 600mm. Each pour must be allowed to harden

prior to pouring the next lift. Alternatively the wall may

be propped to support the lateral load from the wet concrete.

• For higherwalls orwalls with a greater surcharge loading,

Geogrid soil reinforced construction is required.

• For walls founded on clay with a height greater than 2.0m,

Geogrid reinforcement is required.

• Global stability considerations should be checked by an

engineer in poor clay conditions.

• Design assumes a dry excavation (i.e. water table is below

bottom of footing level). If ground water appears in the

excavation, the wall is to be re-designed by a suitably

qualified engineer.

Construction Steps

Special purpose construction such as waterside walls, post

fixing, earthquake zones, and terraces will require additional

engineer’s design.

STEP 1:Excavation/Preparation of Levelling Pad

For walls less than 900mm high, excavate a trench 600mm

wide and sufficiently deep to allow a levelling base of 150mm

+25mm height for each course. Spread coarse sand or 12-

20mm gravel for the levelling base and compact.

For higher walls or in poor foundation material, a footing as

shown in Fig E13 may be necessary. Refer to Table E2.

STEP 2:Installing the First Course

Lay the first course of units side to side over the prepared

base, with the 12mm pinholes on top and kidney holes on

the underside. Maintain the required distance between pinhole

centres of adjacent units. In straight walls, units will touch.

In concave or convex curves, the units will overlap or require

spacing to maintain the 226mm pin distance. Refer to Figs

E8 and E9 for curve installation details.

STEP 3:Installing the Pins

Place the high strength fibreglass connecting pins into each

unit. Use the front holes for a near vertical setback (corners

and curved walls). Use the rear holes for a 1 in 8 setback (i.e.

for every course the wall will set back 25mm). For straight

walls only.

STEP 4:Additional Courses

Sweep the top of the previous course of units clean of any

loose gravel. Place the next course of units so that the kidney

holes fit over the pins of the two units below. Pull the unit

towards the face of the wall until it locks with the pins on

both sides. Repeat steps 3 and 4.

STEP 5: No-Fines Concrete Backfill

Backfill the wall with ‘No Fines’ concrete. All voids inside

and between the units must also be filled. The vertical height

of any pour of ‘No Fines’ concrete is limited to 600mm. Each

pour must be allowed to harden prior to pouring the next lift.

Alternatively the wall may be propped.

STEP 6:Installing Capping Units

Lay capping units, backfill and compact to required grade.

In areas accessible to public vandalism, it is recommended

that the capping units be secured using masonry construction

adhesive or epoxy cement.


Victoria Book 4 E

Surcharge Wall Geogrid Geogrid Height Above Geogrid Length

Height Layers Levelling Pad L (m)

H (m) Layers Soil Type (phi)

1 2 3 4 5 6 7 25 30 35

15 Degree 1.1 2 0.2 0.8 – – – – – 2.2 2.0 2.0

Backfill Slope 1.5 3 0.2 0.6 1.2 – – – – 2.5 2.0 2.0

1.9 4 0.2 0.6 1.0 1.6 – – – 2.4 2.0 2.0

2.3 5 0.2 0.6 1.0 1.4 2.0 – – 2.8 2.4 2.0

2.7 6 0.2 0.6 1.0 1.4 1.8 2.4 – 3.6 2.7 2.4

3.1 7 0.2 0.6 1.0 1.4 1.8 2.2 2.8 4.3 3.0 2.7

5kPa 1.1 2 0.2 0.8 – – – – – 2.4 2.0 2.0

Driveway 1.5 3 0.2 0.6 1.2 – – – – 2.7 2.1 2.0

1.9 4 0.2 0.6 1.0 1.6 – – – 3.0 2.4 2.0

2.3 4 0.2 0.8 1.4 2.0 – – – 3.3 2.7 2.3

2.7 5 0.2 0.6 1.2 1.8 2.4 – – 3.6 3.0 2.5

3.1 6 0.2 0.6 1.0 1.6 2.2 2.6 – 4.0 3.3 2.8

Geogrid Soil-Reinforced Wall Construction Guidelines

Table E3 – Maximum Wall Heights for Geogrid Soil-Reinforced Walls

For taller, more critical walls, the combination of Keystone units

with geogrid soil reinforcement allows walls to be built to heights

of12m and greater,withoutcostlystructural footings. When placed

between layers of compacted soil,geogrids create a reinforced soil

mass, which essentially acts as a larger gravity wall structure.

Geogrids can be used with most existing site-soils and are not

affected by water, micro organisms, alkali or acidic soils. Consult

your engineer for design requirements of Keystone walls using

geogrid soil reinforcement.

NOTES:

• Table E3 is prepared as per AS4678 : 2002. Suitability of

the information contained in the table must be referred to

a qualified professional engineer. These tables are supplied

as a guide, and do not form any part of any contract with

the user.

• Table E3 is based on foundation material with minimum

200kPa bearing capacity.

• Where site conditions and loadings vary from those in the

table, professional engineering advice should be obtained.

• The minimum embedment of wall below ground level is

assumed to be H/20 or 100mm, whichever is greater.

• The length of the 15° backfill slope is assumed to be equal

to the height of wall, H.

*Geogrid with Tul=55kN/m2


Victoria Book 4 E

Cap Unit

Keystone or Pyrmont unit

12-20mm free draining granular material, fill all voids in and around units

Geogrid soil reinforcement to engineer's specification

Compacted backfill material

Compacted roadbase or concrete footing

First course to be embedded below final ground level to engineer's detail (100mm min.)

Drainage pipe (as required)

Reinforced Soil Zone

300mm

Granularmaterial

600mm min.

150mm min.

H

L

Fig E15 – Typical Construction Detail – Keystone/Pyrmont Geogrid Reinforced-Soil Wall

Native soil

Native soil

Geogrid sections are located over pins at the front, pulled taught and staked at the back

Compacted roadbase footing

Free draining granular material

Drainage pipe

Compacted backfill soil

Fig E14 – Typical Installation Detail – Keystone/Pyrmont Geogrid Reinforced-Soil Wall


Victoria Book 4 E

Typical Specification for

Keystone or Pyrmont

Retaining Walls

1. Scope of Work

1.1 Extent

This specification covers the works for construction of

segmental, reinforced-soil retaining structures. The works

include footing excavation, foundation preparation, drainage,

backfill and compaction and related items necessary to

complete the work indicated on drawings and as further

specified.

All retaining wall construction is to be carried out in

accordance with the levels, distances and details as shown

on the drawings and in accordance with this specification.

The Keystone reinforced retaining wall system shall also be

constructed in accordance with the manufacturers installation

guidelines by a suitably qualified and experienced contractor.

1.2 Responsibilities

The Contractor shall be responsible for carrying out the

installation of all retaining walls in accordance with this

specification and the associated contract documents.

2. Standard Specification

Wherever reference is made to Standards Association of

Australia (SAA) the requirements of the editions and

amendments, shall apply to the relevant materials or operations

and be deemed to be incorporated in this specification.

In the case of a conflict between the referenced standard

specification and code and this specification, the more

stringent provisions shall apply.

The following is a summary of standard specifications

applicable to this subsection of the work:

AS1012 Methods of Testing Concrete

AS4456 Concrete Masonry Units

AS3600 Concrete Structures

AS4456.4 Masonry Units – Compressive Strength

AS4678 Earth Retaining Structures

AS1289 Methods of Testing Soils

Materials or operations not covered by the above standard

codes shall conform to the appropriate Australian Standard.

3. General Requirements

3.1 General

Terms used in this specification shall have the meanings

assigned to them as follows:

‘Approved’ shall mean approved in writing by the Engineer.

‘Or equal approved’ shall mean equivalent in performance,

quality and price to that specified and approved by the

Engineer.

Where limits to the properties of soils are defined elsewhere

herein these properties shall be determined by the methods

laid down in AS1289.

The term ‘construction area’ in this Part shall be defined as

an area to be excavated or an area to be cleared and filled.

3.2 Regulations

The Contractor shall complywith all relevantActs, Regulations

and By-Laws in respect of all work specified herein, including

temporary timbering, strutting, guard rails and all safety

measures to be adopted.

3.3 Certification

The Contractor’s Geotechnical Engineer shall certify that the

bearing capacity of the foundation is as per the foundation

requirements specified on the drawings. The Geotechnical

Engineer shall also inspect and certify that the Reinforced

Soil Block material is as specified on drawings with regard

to friction angle, and bulk density.

4. Materials

4.1 Masonry Units

The retaining wall units shall be manufactured in accordance

with AS4456 Concrete Masonry Units. Block types and sizes

for Keystone retaining walls shall be as shown on the drawings

or specified herein.

4.1.1 Tolerance

Permissible tolerance in the manufacture of retaining wall

units shall comply with AS4456.3 - 1997. In the case of

Keystone units, the tolerance of ± 2mm shall not apply to

profiled or textured faces. Non conforming concave distortions

shall be rejected.


Victoria Book 4 E

4.1.2 Strength

Retaining wall units shall be manufactured with a minimum

compressive strength of 10MPa. A minimum of ten (10)

samples must be tested to obtain a mean compressive

strength, tested to failure as per AS4456.4 – 1997 under

normal compressive and laboratory conditions.

4.1.3 Colour

The colour and texture of masonry units shall be as specified

and shall remain consistent with the ‘sample range’ approved

by the project Superintendent

4.1.4 Handling/Storage/Delivery

Keystone units shall be delivered on pallets to minimise

damage during transportation. The Contractor shall store and

handle units so as to prevent units from damage, which may

affect the aesthetic quality or structural integrity of the finished

wall.

4.2 Connecting Pins

High strength pultruded fibreglass pins shall be used to

interlock and align all Keystone units in a running bond

pattern. Pins shall also provide an integral connection between

the Keystone units and the geogrid.

4.3 Geogrids

The reinforcing elements for the reinforced soil structure

shall be as shown on the drawings.

If required, each consignment of geogrids delivered to site

shall be accompanied by a Quality Control Tensile Test

Certificate from the manufacturer.

4.4 Approved Reinforced Soil Block Backfill

Material for backfilling between geogrids for the Keystone

retaining wall shall be ‘Approved Backfill’ defined as sand,

crushed sandstone or broken rock obtained from excavations

or approved borrow areas. Such material shall be

• Free of rock fragments greater than 75mm in size.

• Free of clay lumps retained on a 75mm sieve.

• Free of organic matter.

• Within the following grading requirements;

Sieve Size % Passing by Weight

75mm 100

26.5mm 50 - 100

4.75mm 25 - 75

0.425mm 10 - 50

0.075mm 0 - 20

• Non-plastic in that the fraction passing 0.425mm has a

Plasticity Index of not greater than 15.

• Capable of being brought to a moisture content suitable

for compaction as specified elsewhere herein, under the

weather conditions prevailing on site.

The ‘Approved Backfill’ shall be stockpiled on site, and

inspected and approved by the Geotechnical Engineer that

the material satisfies the specification above the design friction

angle and dry densityvalues as specified on drawings. Testing

for dry density and friction angle shall be in accordance with

section 6 herein.

4.5 Drainage

All retaining walls are to contain drainage systems that

prevent the build up of hydrostatic pressure behind walls. This

is to include a 12-20mm free draining clean hard aggregate,

used to fill all voids within the retaining wall units and to

extend 300mm behind the units.

Drainage is to be installed as per the drawings and as per

the manufacturers recommendations.

4.6 Concrete Works

All concrete for use in footings for retaining walls shall have

a compressive strength after 28 days of 25MPa unless specified

otherwise.

The supply, placement, finishing and curing of reinforcement

and insitu concrete shall comply in every respectwith AS3600.

4.7 Hold and Witness Points

The following shall be deemed a Hold Point:

• Submission of test results and samples of all retaining

wall components.

The following shall be deemed a Witness Point:

• On-site slump and strength testing of concrete.


Victoria Book 4 E

5. Construction of Keystone/Pyrmont

Retaining Walls

5.1 Foundations

Excavation is to be to the lines and grades shown on the

drawings. The reinforced soil block foundation size shall be

constructed as per drawings unless alterations are made by

the Geotechnical Engineer,who may require tests on the sub-

grade material, to be carried out by a registered N.A.T.A.

Testing Laboratory.

The reinforced soil block foundation subgrade shall be proof

rolled with a heavy steel drum roller (minimum applied

intensity of 4t/m width of drum with at least 8 passes) without

vibration. Any material which is soft,visibly deformed, unstable

or deemed unsuitable by the Contractor’s geotechnical

consultant shall be excavated and replaced with approved

fill and compacted to achieve dry densities of between 98%

and 103% of Standard Maximum Dry Density at moisture

content of ±2% of Standard Optimum Moisture Content.

The foundation shall be inspected and approved by the

Geotechnical Engineer, who shall verify that the foundation

bearing capacity exceeds the required bearing capacity as

specified on drawings. The approval of the reinforced soil

block foundation shall be deemed a HOLD POINT.

Detailed excavation for the mass concrete footing shall proceed

following acceptance of the foundation. The footing subgrade

shall be inspected by the Contractor’s Geotechnical Engineer

and any areas deemed soft, unstable or unsuitable by the

Geotechnical Engineer shall be excavated and replaced as

described above.

The footing shall be constructed as shown on the drawings.

It could be shown as compacted roadbase or concrete. For

concrete, the footing shall be poured to the correct level using

formwork edge boards, or other methods which ensure the

correct level of the footing. The concrete footing shall be

screeded flat. The level of the footing or first course of blocks

shall be verified by survey methods, and approved by the

Contractors QA representative. This shall be deemed a

WITNESS POINT.

5.2 Unit Installation

Foundations and all courses are laid level. Batters are achieved

by inserting the fibreglass connecting pins into the appropriate

holes. The Keystone retaining walls shall be constructed with

batters as shown on the drawings.

First course of units shall be placed side by side on the base

levelling pad. Units shall be levelled side to side and front to

back and checked for alignment. The accurate placement of

the first course is most important, to ensure acceptable

horizontal and vertical tolerances. Two fibreglass connecting

pins shall be inserted into the appropriate holes to interlock

and align units.

The front set of pin holes shall be used for near vertical

setback.

The rear pair of holes shall be used for 25mm (1:8) setback.

All voids in units and between units shall be filled with

drainage fill as specified in section 4.5. Drainage fill shall

extend to 300mm behind units.

Units shall be placed in a running bond pattern. Top of units

shall be swept clean of excess material. Kidney holes of units

above shall be positioned over pins in units below. Units shall

be pulled toward the face of the wall to interlock the pins

with units on either side. Levels and alignment of each course

shall be checked. Each course shall be filled, backfilled and

compacted prior to placement of the next course. The Keystone

wall shall be surveyed for vertical level tolerance every 3

courses. This shall be deemed a HOLD POINT.

5.3 Drainage Installation

The drainage measures shall be installed as shown on

drawings. 100mm diameter agricultural pipe shall be used

for subsoil drainage behind the first course of Keystone units.

The subsoil drain shall be placed with a minimum 1% fall as

shown on drawings.

‘T’ piece connection fittings shall be used at all outflow points

to connect the subsoil drainage to a 100mm diameter pipe

stub which extends 300mm past the face of the Keystone

wall. The pipe stub material shall be UPVC or HDPE and shall

be approved by the project Superintendent.

The outflow points shall be at a maximum of 60m centres.

The locations of the outflow points shall be determined by

the Superintendent. The outflow pipe stub shall be supported

on the concrete footing, and shall pass between two Keystone

units with 60mm of the facing removed by sawcutting. The

gap above the pipe in the first course shall be neatly patched

with cement mortar.

The drainage measures shall be inspected by the QA

representative after the installation of the first and second

course is complete. Inspection and approval of the drainage

installation shall be deemed a HOLD POINT.


Victoria Book 4 E

5.4 Placement of Geogrid

The Geogrid shall be placed between Keystone units as

specified on the drawings. Geogrids shall be cut to the

required length. Geogrids may be longer than required, but

shall not be shorter than the specified length shown on the

drawings.

The Geogrids shall be placed with the roll direction

perpendicular to the face of the Keystone wall. Correct

orientation of the geogrids shall be verified by the Contractor.

After compaction, the layer of select backfill below each geogrid,

shall be raked to a depth of 25mm to ensure good interlock

between the geogrid and the select backfill. The Geogrid shall

be laid horizontally on compacted backfill and connected to

the Keystone units by hooking geogrid over the fibreglass

pins. The geogrid shall be pulled taut against pins to eliminate

slack from connections and loose folds. The back edge shall

be staked or secured prior to backfilling to maintain tension

in the geogrid. Each block shall be checked for level accuracy,

as out of position transverse bars will lead to sloping blocks.

If the course above a layer of geogrid is found to be not level,

then the blocks shall be removed, and the geogrid repositioned

to ensure levelness.

For a straight length of wall, the geogrids shall be laid side

by side without joints or overlaps. Where the wall is convex,

the geogrids shall not be cut, but shall be overlapped with a

minimum of 75mm of compacted fill between them. For a

concave wall the position of the layers of grid shall be

alternated between consecutive geogrid layers to cover the

triangular gaps between strips of geogrid. Refer to Fig 5.4.

The QA Representative shall inspect and keep records of the

position of grid and the type of grid placed for each layer of

geogrid. The number of courses between each successive

layer of geogrid shall be noted. The QA Representative shall

also check this. This shall be deemed a WITNESS POINT.

5.5 Placement of Reinforced Soil Backfill

Prior to placement of ‘Approved Backfill’ in the reinforced soil

block, the Geotechnical Engineer shall approve the material

and confirm that the friction angle and dry density of the

material is in accordance with the drawings for that particular

section of the project. This shall be deemed a HOLD POINT.

All backfill imported or otherwise shall be as specified on

the drawings. Backfill shall be spread in a maximum of

200mm layers, in such a manner that minimises the voids

directly underneath the geogrid. Fill should be deposited

using suitable plantwhich causes fill to cascade onto geogrids.

Placement of fill on top of the geogrids shall start from the

wall face and work back from the wall face in order to minimise

slack or loss of pretension from the grid. Care should be taken

to not mix the reinforced soil block backfill material with the

drainage material. If backfill material mixes with the drainage

material, then the drainage material is to be removed and

replaced with clean material.

Compaction shall be to 98% of Standard Maximum Dry

Density. Compaction shall start at the wall face and work

back from the wall face. Compaction testing shall be in

accordance with section 6 specified herein. Compaction testing

shall be deemed a WITNESS POINT.

Tracked construction equipment shall not be operated directly

on the geogrid. A minimum thickness of 150mm of backfill

material shall be placed prior to the operation of tracked

construction equipment. Rubber tyred equipment may pass

over the geogrids at very slow speeds. Sudden braking or

sharp turning shall be avoided to prevent displacement of

geogrids.

Construction plant and all other vehicles having a mass

exceeding 1000kg shall be kept at least 1m from the back of

the Keystone units. Compaction of the 1m zone behind the

Keystone units shall be restricted to:

• Vibrating rollers with a mass < 1000kg

• Vibrating plate compacters with a mass < 1000kg

• Vibro tampers having a mass < 75kgWall Face

Geogrid

Fig 5.4 – Typical Geogrid Layout


Victoria Book 4 E

Surface drainage during and after construction of the wall

shall be provided to minimise water infiltration in the

reinforced soil zone.

5.6 Hold and Witness Points

The following shall be deemed a HOLD POINT:

• Approval of foundation material by the Geotechnical

Engineer.

• Inspection and approval of ‘Approved Backfill’ for use in

reinforced soil block by the Geotechnical Engineer.

• Survey of the Keystone Wall every 3 courses.

• Inspection and approval of the drainage installation by the

QA Representative.

The following shall be deemed a WITNESS POINT:

• Survey verification that the first course is installed at the

correct level, and inspection and approval of footing by

the QA Representative.

• Inspection of level and type of geogrid at each layer by the

QA Representative.

• Compaction Testing by the Geotechnical Engineer.

6. Material Testing

6.1 Testing of ‘Approved Backfill’

Each source of ‘Approved Backfill’ shall be pretreated by 5

cycles of repeated compaction, and then tested for dry density

and friction angle. Material for use as ‘approved backfill’ shall

be inspected and approved for use by the Geotechnical

Engineer. A stockpile at least equivalent to 5 days reinforced

soil wall construction shall be maintained on site at all times.

This will allow time for friction angle testing of the approved

backfill should visual inspection of the material when it is

received on site indicate that testing is required.

Notwithstanding the above the following minimum testing

shall be carried out:

• Dry Density shall be tested at a frequency of 1 test per

400m3 of approved backfill.

• Friction angle shall be tested at a frequency of 1 test per

2000m3 of approved backfill.

If the dry density results are not within ±5% of the specified

design value, then the Engineer shall be notified, and the

material not approved for use until the design has been

verified.

6.2 Testing for Compaction

Compaction will be checked by standard maximum dry density

test and field density test for materials other than sand or by

the density index and field density tests for sands as specified

on drawings and herein.

Tests will be carried out in groups of at least three, and

compaction of the layer concerned will be considered to be

satisfactory if no single result falls outside the specified

density range. Should the results not reach this standard the

Sub-Contractor shall again roll the area, if necessary after

scarifying, adding water, blading to reduce the moisture

content and/or removing and replacing excessively moist fill

as may be required.

Should the Geotechnical Engineer consider that the depth of

insufficiently compacted material is greater than can be

effectively compacted from the surface, material shall be

removed to a depth at which compaction is satisfactory and

replaced and compacted in 200mm maximum layers.

The standard maximum dry density referred to herein for

materials other than sand shall be maximum standard dry

density as determined in accordance with AS1289 - Test

numbers 5.1.1.

The modified maximum dry density referred to herein for

materials other than sand shall be the maximum modified

dry density as determined in accordance with AS1289 - Test

5.2.1.

The field density referred to herein for all materials shall be

the dry density of the material in place as determined in

accordance with AS1289 - Test 5.3.1

The percentage of the standard maximum dry density (Dry

Density Ratio) elsewhere herein for materials other than sand

shall be calculated from the formula given in AS1289.5.4.1.

The maximum and minimum densities of cohesionless

materials shall be determined in accordance with AS1289 -

Test E5.1

The Density Index specified elsewhere herein for sands shall

be calculated from the formula given in AS1289.E6.1.

6.3 Frequency of Testing

The following testing frequencies relate to acceptance on a

‘not-one-to-fail’ basis. The testing should be carried out in

essentially randomly chosen locations and at the frequencies

as given below. However, it may be appropriate to undertake

testing in specific locations, based on visual appearance or

past experience.


Victoria Book 4 E

Where a test or group of tests is carried out on an area which

has been subjected to essentially the same preparation and

compaction procedures, the whole of this area is considered

to be represented by this test or group of tests. The uniform

area is generally known as a work lot. On this basis, if one

or more tests indicate compliance with the specification has

not been achieved, the whole of the area which has been

submitted for testing is deemed not to comply, unless it can

be demonstrated that the area in which the non-complying

test result(s) can reasonably be separated from the whole. It

should not be assumed a test result applies only to the area

immediately surrounding it.

Required frequency of testing, is not less than 1 test per layer

of 200 mm thickness per material type per 400m3 which is

1 test per layer per 100 linear metres of wall construction. If

different sources of ‘approved backfill’ are used within the

100 linear metre work lot, then 1 test per type of material is

required. If the work is staged in sections of less than 100

linear metres, then 1 test per section is required.

The testing frequency may be re-assessed to the approval of

the Engineer, if a high degree of uniformity becomes evident

during construction.


F CUSTOM ENGINEERED WALLS

444F44Masonry Design Guide

BORAL MASONRY


F2 July 2005 | BORAL MASONRY DESIGN GUIDE

Victoria Book 4 F

Engineered

Retaining Wall Systemsfor domestic and commercial landscaping, roadside

and custom engineered retaining wall applications

Boral Keystone, Pyrmont and Keysteel Retaining WallSystems provide a proven and versatile platform for thedevelopment of custom engineered high performanceretained earth structures.

Boral has developed alliances with a number of suitablyexperienced engineering companies that can provideprofessional assistance with the custom design andinstallation of Keystone, Pyrmont and Keysteel retainingstructures.

Please contact Boral Masonry in your region for assistancewith your high performance, engineered retaining wallprojects.

F3BORAL MASONRY DESIGN GUIDE | July 2005

Victoria Book 4 F

Keysteel Custom Engineered


• Keysteel™ Custom Engineered Retaining

Wall Systems

Boral Keysteel is a high performance engineeredretaining wall system for applications requiring wallheights in excess of 6m and/or where critical surchargeloadings are present. Boral Keysteel is an internationallyproven system that integrates the superior strengthand durability of Keysteel blocks with steel-ladder soil-reinforcement to provide engineered solutions for themost demanding retaining structures.

• Gravity Retaining Walls

• Mass Gravity Retaining Walls

• Geogrid Reinforced-Soil Retaining Walls

• Steel-Ladder Reinforced-Soil Retaining Structures

• Bridge Abutments

• Stream or Drainage Channels

• Erosion Prevention

• Tunnel Access Walls

• Wing Walls

• Embankment Stabilisation

• Terraced Walls

• Seawall Applications

• Soil-Anchor & Rock-Anchor Walls

• Fencing, Railings & Barriers


Victoria Book 4 F

INTRODUCTION

Boral Keysteel is an internationally

proven, high performance retaining

wall system that integrates the

superior strength of Keysteel blocks

with steel-ladder soil-reinforcement,

and is ideally suited to retaining

structures in excess of 6m high and

for critical surcharge loadings.


Boral Keysteel installations are

individually engineered to match the

application criteria.

Boral has developed alliances with

a number of suitably experienced

engineering companies which can

provide professional assistance with

the design and installation of

Keysteel retaining structures.

Please contact Boral Masonry

Technical Services in your region for

assistance with Keysteel projects.

COLOURS

Boral Keysteel is made-to-order in

the same range of colours as

Keystone, allowing integration of the

two products within the one project.

Please refer to colour swatch


current colours.

Keysteel®

High Performance EngineeredRetaining Wall Systems


275

100

455

Flushface Straight Sided Cap

275

100

455

Steel Pins(hot-dip galvanised)

Lifting Bars


Standard Unit 36 11




Pins (steel) 2 pins per full unit

hot-dip galvanised steel

Lifting Bars (Keysteel units should be lifted by

two people using the Keysteel lifting bars)

Specifications

305

200

455

Standard Unit

305

200

455

Flushface Unit

Availability & Colours• All Keysteel products are made-to-order.

• Lead times apply Please consult with the Boral Masonry

sales office in your region.

Bluestone Brown

Sunset Terracotta

Natural Parchment

Charcoal


Victoria Book 4 F

Typical Keysteel® Application Layout

Keystone unit

Pylon

Cut ladder around pylon Where piles prevent installation of ladders refer to engineers detail.

Keysteel unit

Keysteel unit

Soil reinforcementladder

Wall face

Keysteel unit Soil reinforcingladder

Fig F1 – Typical Construction Detail – Keysteel wall

Fig F2 – Typical Curved Wall Detail – Keysteel Fig F3 – Typical Straight Wall Detail – Keysteel


Victoria Book 4 F

Finished grade Threaded pipe coupling

Footing step (optional)

Galvanised pipe

Top of wall stepped (optional)

Keystone unit

Granular backfillGeogrid (if required)

Stiff firm soil

Galvanised steel pipe

Soil anchors

Galvanised pipe loop connector

Galvanised pipe,loop connector and soil anchors (staggered installation)

1200mm cts nominal

TYPICAL PLAN VIEW

TYPICAL WALL ELEVATION

Keystone unit

Geogrid

Galvanised steel pipe

Loop connector

Granular fill

Soil anchor todesign details

TYPICAL CONNECTION DETAIL

Cap unit

Keystone units

Soil anchors to site specific design

Soil failure plane

5˚

Stiff firm soil

Finished grade

Leveling pad to engineer's detail

Drainage pipe

See connection detail

300mmnominal

TYPICAL SIDE ELEVATION

1

8

Typical Soil-Anchor Application

Fig F4 – Typical Soil-Anchor Detail


Victoria Book 4 F

Temporary face support and drainage system

Finished grade Footing step

Reinforcing barto design details

Geogrid Soil Anchor todesign details

Top of wall stepped (optional)

Keystone unit

Reinforcing bar to project specifications Geogrid to project

specifications Concrete backfillDrainage net

Rock anchors

Expansion joint materialto design details TYPICAL PLAN VIEW

TYPICAL WALL ELEVATION

Keystone cap

Keystone unit

Horizontal reinforcing bar to design details

Vertical reinforcing bar to design details

Concrete backfill to design detail

Geogrid at 600mm vertical centres extended to wall face between reinforcing barRock anchor

system to design details

Granular material wrapped in geotextile

Temporary concrete and mesh facing support system with drainage to design details

Drainage netto design details

Finished grade

Levelling pad

Drainage pipe

1

8

See anchorage detail

1500mmtypical

300mmnominal

TYPICAL SIDE ELEVATION

Keystone unit

Geogrid

Reinforcing barto design detail

Thread bar todesign details

Steel plate and securing nuts to design detail

Concrete backfill

Rock anchorto design detail

TYPICAL ANCHORAGE DETAIL

Typical Rock-Anchor Application Layout

Fig F5 – Typical Rock-Anchor Detail


Victoria Book 4 F

Engineering

All water application projects should be designed by a suitably

qualified engineer. The Keystone Retaining Wall System has

been used in numerous international projects where the

blocks are subjected to high velocity flood water, wave action

and tidal action.

Spacing of Geogrid

As with all geogrid soil reinforced Keystone walls, the spacing

of the geogrid should not exceed 600mm, to prevent bulging

between the grid layers.

Suitability of Keystone Blocks in a SeawallApplication

It is recommended that if the Keystone units are submerged

in salt water, then marine grade Keystone units should be

used. Minimum order quantities apply to these units.

NOTE: Product colours will be different due to the use of

marine grade cement.

Typical1900mm

Keystone Cap Unit

Filter Fabric

Keystone block

Nonwoven filter fabric

Geogrid as per design

Water level

Free draining granular material (less than 10% passing the #200 sieve, no organic material)

10-20mm crushed rock, fill cores and voids of Keystone units

Native soil

Impermeable soil layer 300mm

Compacted aggregate or crushed rock

150mm min.

600mm min.

150 - 200mmrip-rap

Fig F6 – Typical Construction Detail – Keystone Seawall Application

Undermining of Foundation Wall

Greater embedment of units, concrete footings (piered or

otherwise), Keystone units keyed to a concrete foundation

are all means of preventing undermining of the wall

foundation. Rip-Rap in front of the wall will also help to prevent

erosion.

Loss of Material through Wall Face

Filter fabric used behind the 300mm drainage layer will

prevent loss of retained soils during fluctuation in water level.

Differential Water Pressures

Fluctuations in water levels and rapid draw down may induce

differential water pressures across the face of the wall and

need to be addressed.

Test Reports

Tests have been carried out on the high velocity flow effects,

wave action and sudden draw down and Manning’s ‘n’

determination. These test results are available on request.

Typical Seawall Application Layout


Victoria Book 4 F

When terracing walls, they are effectively being split into

sections. This is done for a number of reasons. For example,

to level off a sloping front or backyard, to increase the aesthetic

appeal of the garden and in some instances to reduce the

single wall heights where by they still act as gravitywalls and

thus minimise the need for geogrid. In such instances,

however, the upper terrace wall can put pressure on the lower

terrace if the walls are too close together. Multiple terrace

walls in close proximity to each other, can have structural

stability issues related to the lower walls not having the

capacity to carry the loads developed by the upper walls.

Question:

How far apart do the terrace walls have to be to perform as

individual gravity walls?

Answer:

As a rule of thumb, the minimum distance between the wall

terraces must be at least 1.5 times the height of the lower

wall.

Example:

Cap unit

Keystone or Pyrmont wall

Keystone or Pyrmont wall

L = 1.5 x (H1)

L = minimum distance between terraces

H 2

H 1

Fig F7 – Typical Construction Detail – Terraced Wall Application

If the lower gravity wall is 1.2m tall, then the minimum

recommended spacing between terraces is 1.8m. This rule

also applies to walls with more than two terraces. The distance

between any two terraces must be at least twice the height

of the lower adjacent terrace wall for multiple terraces.

NOTE: This simple rule of thumb does not address global

stability issues where walls are built on steep slopes or over

poor soils of low friction strength. If these conditions exist,

then contact your engineer.

Question:

What if there isn’t enough room to space the terraces

according to this rule (1.5 x H1 minimum)?

Answer:

The wall can still be built, but the effect of the upper terrace

on the lower terrace and overall stability must be taken

into account when designing the walls. When the terraces

are close together, the design analysis may model the

structure as a single taller wall to account for the added

load from the upper terrace wall on the lower walls.

Typical Terraced Wall Application Layout


Victoria Book 4 F

Fences can be incorporated into the Keystone Retaining Wall

System by placing fence posts into the Keystone cores or

behind the wall.

NOTE: The following recommendations are suitablefor fences with no wind loadings.

Fence posts should be embedded through a minimum of

three courses (600mm minimum) and then core filled with

concrete. Only those units with the fence posts need to be

core filled with concrete, the remaining filled with drainage

material.

Fence posts positioned behind the wall should be embedded

700mm minimum and encased in concrete.

When constructing a soil reinforced wall, the Geogrid may

be cut to allow for placement of fence posts as per the Geogrid

manufacturer specifications.

It is important that these walls be designed to accommodate

any additional wind loads from fencing (eg. extra embedment).

700mm

900mm

1824mm max.

Fig F8 – Typical Fencing Detail

Typical Fencing Application Layout


Victoria Book 4 F

Railing, guard rail, and traffic barrier requirements for

retaining walls are not clearly defined in design codes nor

are they properly addressed in many site plans. Many times

railings and barriers are added as an afterthought which can

become a costly and logistical issue when no provisions are

made in the original retaining wall layout and site design.

Guards and barriers require a common sense approach by

the site designer considering the proximity of a wall structure

to people and traffic. Sufficient space must be reserved for

such installations.

It is important that these walls be designed to accomodate

any additional loading these guards and barriers may impose

on the Keystone wall.

Typical 800mm

Guardrail Traffic Barrier

Load

1000mm min.

Load

Typical 900mm

150mm

Typical 900mm

Railing – offset Railing – offset

Load Load

900mm min.

Additional Geogrid layer turned upwards and wrapped around void former at 400mm below ground level

Fig F9 – Railing & Barrier Details

Typical Railing & Barrier Application Layout

July 2005

Other Regional Sales Offices

NSW Clunies Ross Street, Prospect, 2148 T: (02) 9840 2333

F: (02) 9840 2344

ACT 16 Whyalla Street, Fyshwick, 2609 T: (02) 6239 1029

F: (02) 6280 6262

South Australia Main North Road, Pooraka, 5095 T: (08) 8262 3529

F: (08) 8260 3011

Queensland 62 Industrial Ave, Wacol, 4076 T: (07) 3271 9292

F: (07) 3271 1581

North Queensland:

Cairns 8 Palmer Street, Portsmith, 4870 T: (07) 4035 1888

F: (07) 4035 1208

Townsville 360 Bayswater Road, Garbutt, 4814 T: (07) 4725 6285

F: (07) 4725 6043

Mackay David Muir Street, Slade Point, 4740 T: (07) 4955 1155

F: (07) 4955 4130

Customer Support Victoria

1. Stock colours Colours other than stock colours are made to order. Not all colours displayed in this brochure are available in all states.

(Contact your nearest Boral Masonry office for your area’s stock colours.) A surcharge applies to orders less than the set minimum

quantity.

2. Brochure colours The printed colours in this Masonry Design Guide are only a guide. Please ask to see a sample of your colour/texture

before specifying or ordering.

3. Colour and texture variation The supply of raw materials can vary over time. In addition, variation can occur between product types and

production batches.

4. We reserve the right to change the details in this publication without notice.

5. For a full set of Terms and Conditions of Sale please contact your nearest Boral Masonry sales office.

6. Important notice Please consult with your local council for design regulations prior to the construction of your wall. Councils in general

require those walls over 1m in height and/or where there is loading such as a car or house near the wall be designed and certified by a

suitably qualified engineer.

Orders, Product Samples and Sales Enquires

Victoria Level 1 Port IT, 63-85 Turner Street, Port Melbourne, 3207 T: (03) 9363 1944

F: (03) 9363 6008

Technical Enquires

Specifier Line 1300 360 255

Internet www.boral.com.au/masonry

® Heathstone and Pyrmont are registered trademarks of Boral Masonry Limited.

® Keystone and Gardenwall are each registered trademarks of Keystone Retaining Wall Systems, Inc.

under licence by Boral Masonry Limited. ABN 13 000 223 718

© Boral Masonry - all rights reserved 2004.

Documents

Masonry Wall BOR11999 VIC Manual Bk4