Rein Earth Manual - LargePanel

8/12/2019 Rein Earth Manual - LargePanel

1/21

CONSTRUCTION AND QUALITY CONTROLPROCEDURES MANUAL FORREINFORCED EARTH STRUCTURES

CONCRETE FACING - Rectangular Large Panels

The Reinforced Earth Company


2/21

CONSTRUCTION AND QUALITY CONTROL PROCEDURES MANUAL

CONSTRUCTION ANDQUALITY CONTROL

PROCEDURES MANUAL

ContentsI. Preface .........................................................................................................1

II. Non-Disclosure and Disclaimer.....................................................................2

III. Introduction ...................................................................................................3 A. Purpose ........................................................................................3B. Responsibilities.............................................................................3C. Plans, Specifications, Layout ........................................................3D. Components .................................................................................4E. Materials and Services Provided by

The Reinforced Earth Company ...................................................4F. Equipment, Materials, Tools

and Work Supplied by Contractor ................................................. 4

IV. Handling Reinforced Earth Materials ............................................................6 A. Concrete Facing Panels ...............................................................6B. Reinforcing Strips, Fasteners and Joint Materials .........................7

V. Construction Procedures ..............................................................................8Erection Tolerances .........................................................................10

A. Foundation Preparation ..............................................................10B. Erecting the Initial Panel Course................................................. 10C. Joint Materials.............................................................................12D. Backfilling....................................................................................13E. Reinforcing Strips .......................................................................14F. Constructing Second and Subsequent Courses .........................15G. Completion of Wall......................................................................17

VI. Condition-Cause Relationships .....................................................................18

VII. Safety Tips for Unloading Reinforced Earth Products ..................................19


3/21

CONSTRUCTION AND QUALITY CONTROL PROCEDURES MANUAL Page 1

I. PREFACE

This Construction and Quality Control Procedures Manual has been prepared as a guidein building Reinforced Earth structures.

Its contents should be thoroughly reviewed by the Contractor and the superintendentresponsible for construction prior to the delivery of Reinforced Earth materials to the job site.

The Reinforced Earth Company will provide construction advisors to assist the Contractor in the implementation of correct construction procedures. However, in the event of any conflictbetween the Plans, Specifications or Contract Documents and this Manual, the former willprevail. If there is any doubt with regard to any aspect of Reinforced Earth construction,contact The Reinforced Earth Company before commencing or continuing work.

Compliance with the guidelines in this Manual does not relieve the Contractor of theresponsibility to adhere to the project Plans, Specifications and Contract Documents, or for complying with all safety standards and procedures, including fall protection, at the job site.

2000 The Reinforced Earth Company. The information contained in this Construction and Quality Control Procedures Manual is provided as aguideline for the construction of Reinforced Earth structures comprised of certain materials supplied by The Reinforced Earth Company. This Manual isnot to be used for any other purpose. Reproduction of the contents of this document in whole or part without the written consent of The Reinforced EarthCompany is expressly prohibited. All rights reserved.

Reinforced Earth, the cruciform shape of panels and the Reinforced Earth logo are registered trademarks of The Reinforced Earth Company.


4/21

CONSTRUCTION AND QUALITY CONTROL PROCEDURES MANUALPage 2

II. NON-DISCLOSURE NOTICEAND DISCLAIMER

1. This Document is the property of The Reinforced Earth Company (RECO) and containsinformation which is proprietary to The Reinforced Earth Company, including the patentedprocess and techniques relating to mechanically stabilized earth (MSE) structures known as"Reinforced Earth" structures.

2. This Document is being made available solely for use in connection with your interest or participation in the proposed Reinforced Earth project, and for no other purpose.

3. Except as specified in paragraph 2 above you must not, without the prior express written consentof The Reinforced Earth Company, use any of the information contained in the Documentwhether to construct, design, manufacture, fabricate, assemble, produce or install, or otherwiseutilize - or cause the same or any of them to be done - any elements of Reinforced Earth(whether or not patented), or special forms of equipment unique to the production, manufacture,fabrication, assembly, installation, or utilization of Reinforced Earth, or for any other purpose.

4 This Document and the information contained herein must not be copied or disclosed in anymanner or form, in whole or in part, to any third party without the prior express written consent of The Reinforced Earth Company.

5. Receipt of Document gives no entitlement to any property right in the Document or in theinformation contained therein by virtue of the temporary supply of the Document in accordanceherewith.

6. Reinforced Earth structures designed by The Reinforced Earth Company comprise or are basedsolely upon:

(a) the internal stability of the Reinforced Earth structure based upon the design assumptions noted on all RECO drawings relating to the structure and the external loads,

surcharges and site geometries supplied by or on behalf of the Owner;

(b) the layout and geometry of the structure based upon survey details, plans and drawings supplied by or on behalf of the Owner; and

(c) the Job Specifications.

The design does not include a check of the overall stability of the foundation soils below andbehind the structure, nor a check of any potential failure planes external to the structure, nor acheck of the stability of any permanent or temporary slopes above or below the wall or temporaryexcavations. Based on the completeness and accuracy of the above information used or reliedupon in designing the structure, The Reinforced Earth Company warrants the internal stability of the structure only.

7. Upon demand, the Document and all copies thereof must be immediately surrendered andreturned to The Reinforced Earth Company.


5/21


III. INTRODUCTION

Reinforced Earth is a composite material formed by theassociation of a frictional soil and reinforcing strips. Inconcept, it is like reinforced concrete; that is, ReinforcedEarth is an economical means of improving themechanical properties of a basic material, earth, byreinforcing it with another, steel.

Stresses produced within the soil mass are resisted bythe strips; stresses are transferred to the strips byfriction.

A Reinforced Earth structure constructed using thismaterial is shown as the "reinforced volume" in Figure 1.Concrete panels are used at the face of the reinforcedvolume to prevent erosion of the backfill and to providean attractive, finished appearance.

Figure 1

A. PURPOSE

This document is intended to provide the Owner,Contractor, Engineer and the inspection staff - thosewho are responsible for overall quality control andinspection during construction - with the criterianecessary to monitor the erection of Reinforced Earthstructures for compliance with the Plans, Specifications,and Contract Documents.

B. RESPONSIBILITIES

It is the Contractor's responsibility to completeconstruction in strict accordance with the Plans,Specifications, and Contract Documents. To assist theContractor in this regard, The Reinforced EarthCompany provides recommended erection proceduresin this Procedures Manual. Nothing in this document isintended to relieve the Contractor of the responsibility of complying with all safety standards and procedures,including fall protection, at the job site.

The Contractor and Owner should verify that theErecting Contractor's on-site personnel are inpossession of and are familiar with therecommendations of this Procedures Manual.

Technical Advisors from The Reinforced EarthCompany may assist the Contractor with materialscheduling and coordination, and provide advice on therecommended construction procedures for ReinforcedEarth structures as set out in this Manual. Technical

Advisors are available on-site during initial constructionand thereafter on a request basis.

Technical Advisors are not available on-site on afull-time basis, and are not provided with theintent of replacing the Owner's and Contractor'sdesignated quality control and/or inspection staff.

Only the Engineer can enforce the requirements of the Plans, Specifications, and ContractDocuments.

C. PLANS, SPECIFICATIONS, LAYOUT

1. Prior to commencing any site work, the Contractor should verify that the latest issue of the Plans,Specifications, and Contract Documents - approved

for construction - are being used to build the Work.

2. The Contractor should also confirm that the Work isbeing constructed at the proper location by verifyingline, grade, offset, and other location criteria.


6/21


D. COMPONENTS

Reinforced Earth structures consist of the following:

Concrete Leveling Pad - A cast-in-place unreinforcedconcrete leveling pad serves as a smooth, level surfacefor placing panels. Refer to the Plans and Specificationsfor dimensions and requirements.

Precast Concrete Facing Panels

Full-size-or A n panels are used for the majority of the structure. The subscript "n" in panel designationsindicates the number of reinforcing strip (tie strip)connections on each panel.

Alternating full and half height panels of varyingheights are typically required in the initial course.

Top-course panels may have a flat top and vary in

height to provide a stepped transition at the top of the structure.

Specially cut, bent, or sloping panels as required bythe geometry of the structure.

Facing Panel Joint Materials

Rubber Bearing Bloks of standard thickness areplaced in the horizontal joints throughout thestructure to prevent concrete-to-concrete contact.Rubber shims are used as needed to adjust for

minor variations in panel height. Filter cloth is applied with adhesive to the backfill

side of the horizontal and vertical joints.

Reinforcing Strips - Ribbed strips are typically suppliedin a 50-mm (2.0 in.) width and varying lengths asrequired by the design of the structure. They are either galvanized for permanent applications or black steel for temporary applications.

Fasteners - During construction, reinforcing strips arefastened to tie strip connections embedded in the backof each facing panel using in. diameter bolts, washersand nuts made of structural galvanized steel.

Select Granular Backfill - Backfill conforming toContract Specifications must be used within thereinforced volume.

E. MATERIALS AND SERVICES PROVIDEDBY THE REINFORCED EARTH COMPANY

Engineering and design of the Reinforced Earthstructure.

Precast concrete facing panels. Horizontal and vertical joint materials and shims. Reinforcing strips.

Structural bolts, washers and nuts. One set of facing panel lifting devices. Delivery of Reinforced Earth Company-furnished

materials to the site (F.O.B.), with two hours of timeallowed for unloading.

Sublicense to build the structure. Initial on-site technical assistance.

Reinforcing strips, bolt sets, filter fabric, adhesive,Bearing Bloks, and other special items provided by TheReinforced Earth Company are bundled and packed tominimize damage in unloading and handling.

Materials should be thoroughly inspected upondelivery to the job site. Any damaged item shouldbe set aside and The Reinforced Earth Companynotified immediately. Materials should behandled and stored to prevent damage or theft.Filter fabric must be stored in a shelteredlocation and protected from sunlight.

Certificates of compliance with project specifications for all materials are furnished by The Reinforced EarthCompany. However, it is the Contractor's responsibilityto verify that all materials received at the job site are in

accordance with shipping documents and projectrequirements. Any discrepancies should be reportedimmediately to The Reinforced Earth Company.

To prevent construction delays, the Contractor should continuously monitor the quantity of materials on hand to ensure an adequate supplyconsistent with the Plans, Specifications, andContract Documents.

F. EQUIPMENT, MATERIALS, TOOLS ANDWORK SUPPLIED BY CONTRACTOR

Equipment

Panel lifting - A small hydraulic crane, boom truck or similar equipment is required. A standard 5 -in.thick A n facing panel weighs 3400 lbs.; the largest 5-in. thick panel weighs 5300 lbs. Panels witharchitectural finishes may be heavier.


7/21


Backfilling - Dump trucks, scrapers, dozers, graders,front-end loaders, water trucks, etc. are used for hauling, dumping and spreading backfill (Specificequipment selection will depend on backfill, liftthickness, compaction specifications, etc.).

Compaction - Large smooth-drum vibratory rollersare used for mass compaction of most backfills.

Fine uniform sands are compacted using a smooth-drum static roller.

Small walk-behind vibrating rollers or flat-platecompactors are needed for compaction within 3 ft.of the facing panels.

Figure 2

Materials and Tools Supplied by the Contractor

Clamps, one per vertical joint for the length of structure under construction. Additional clamps willbe needed for bracing the initial course of panels(Figure 2).

Wooden wedges in a quantity at least sufficient toprovide 4 to 6 wedges per vertical joint for the

length of structure under construction (Figure 2). wooden spacer between panels on initial course(Figure 2).

Nylon slings for unloading panels. Lumber for bracing the initial course of panels

(Figures 18 and 19). Crowbars (pinch bars). A four-ft. carpenter level. Wrenches or socket sets (7/8 in.). Claw hammers and nails. A sledge hammer. A chalk line. Brooms or brushes. A plumb bob. Equal length cables with shackles to connect to

panel lifting devices. Survey equipment. Shims for Clamps (Figure 21).

Summary of Work Performed by Contractor

Site preparation including excavation andinstallation of drainage systems as required.

Forming and pouring concrete leveling pad(s).

Construction of the Reinforced Earth structureconsisting of the erection and positioning of facingpanels, installation of joint materials, connection of reinforcing strips, and placement and compaction of Select Granular Backfill.

Placement of any concrete coping, traffic barrier, or other C.I.P. concrete as required.


8/21


IV. HANDLING REINFORCEDEARTH MATERIALS

A. CONCRETE FACING PANELS

Panel delivery. Prior to the start of construction, theContractor should establish a panel delivery schedulewhich will allow The Reinforced Earth Company'sprecast operations group to match its panelmanufacturing/delivery output to the Contractor'sconstruction schedule.

Panels are usually delivered on flatbed trailers in stacksof four or five. The delivery point is made as close to thestructure as a truck can be driven under its own power (Figure 3).

Unloading panels. Under normal conditions, a two hour period is allowed per delivery for panel unloading. In thistime, panels may be placed directly into the structureduring construction or temporarily stacked followingeither of these methods:

1) by using lifting devices to lift and handle individualpanels (Figures 4 and 5), or 2) by using slings to lift and handle individual panels or stacks of panels.

Care must be taken to protect facing panels fromdamage during handling and storage.

Unloading or handling panels with a forklift isnot recommended.

Panels can be stored at the job site by re-stacking.Select a location with firm, level ground for both stabilityand to protect panels from staining. Carefully lift andplace each panel face down on the nylon pads of thedunnage. Stacks should be no more than five panelshigh with dunnage used between each panel asillustrated in Figure 6.

Never re-stack panels without dunnage. Never place panels face down directly on the ground.Never stand panels up on end.

Note: All dunnage remains the property of The Rein-forced Earth Company. It should be stacked and madeavailable for pick-up as soon as it is no longer neededfor storage.

Figure 3

Figure 4

Figure 5

Panels. Should be securely set and blocked on firm,level ground to prevent damage and staining duringstorage.


9/21


Figure 6

B. REINFORCING STRIPS, FASTENERSAND JOINT MATERIALS

Figure 7

Reinforcing strips and fasteners. Strips may be up to36 ft. long and are delivered to the site in bundles of 25each. Each bundle weighs approximately 30 lbs. per linear ft. Storage in the open is acceptable but bundlesshould not be placed directly on the ground. Sets of 500bolts, washers and nuts are packed in containers, eachweighing 125 lbs. (Figures 7 and 8).

Figure 8

Bearing Bloks. Rubber Bearing Bloks are packed incartons each weighing 50 to 75 lbs.

Figure 9

Filter Cloth, Adhesive, Foam. Filter cloth is supplied in18 in. wide rolls. Adhesive for filter cloth is supplied in

appropriate containers (Figure 9). Adhesive containersmust be kept dry. Foam strips (if required) are suppliedin plastic bags, each containing up to 100 of the 2 in.square, 7 to 9 foot strips. In addition to normal security,foam must be stored in a sheltered location, protectedfrom sunlight.


10/21


V. CONSTRUCTIONPROCEDURES

The basic erection sequence for a Reinforced Earthstructure can be summarized in these steps:

Prepare the site including excavation and

installation of drainage systems if required.

Form and pour leveling pad (see tolerances Step A-3).

Set and brace the initial course of facing panelswhich consists of alternating half- and full-heightpanels.

Spread and compact backfill in lifts up to lowestlevel of panel tie strips.

Connect reinforcing strips to panel tie strips.

Spread and compact backfill in lifts to the top of thehalf panels.

Set second course of full panels.

Repeat cycle of backfilling and compacting in lifts,connecting strips, setting panels until design heightis reached.

As each course is completed, remove the woodenwedges from the panels in the course three levelsbelow.

Set top panels, connect strips, complete backfillingand compaction.

Remove all wedges and clamps.

Install concrete coping, traffic barriers, or any C.I.P.concrete as required.

Figure 10

The finished appearance of a Reinforced Earth structuredepends to a large extent on the care taken in erectingand positioning facing panels. For this reason, particular attention must be paid to the initial course of facingpanels and to backfill placement. Close attention todetail and accuracy at this point will help ensure trouble-free and rapid construction of the remainder of thestructure.

The following panel position and alignment proceduresshould be reviewed prior to the start of construction.

Lifting, placing and spacing panels. Panels can belifted from the horizontal, or stacked position, directly toa vertical position by attaching a lifting device to each of the two cast-in-place lifting inserts at the top edge of thepanel (Figure 10). Use dunnage as blocking to preventdamage as each panel rotates from horizontal tovertical.

Figure 11

When placing the initial course of panels, insert a spacer between each panel at the base of the front faceof the wall (Figure 11). Note: A minimum of one spacer should remain in place until the next panel joint (in thedirection of panel placement) has been established by aspacer. Subsequent courses of panels will be placed bycentering the panel in its respective slot (Figure 29).


11/21


Figure 12

Figure 13

Check alignment. Visually check the alignment of eachpanel in relation to either the control line on the leveling

pad for the initial course of panels or to the panel belowin subsequent courses. Make adjustments with acrowbar on the fill side of the panel (Figure 13) so thatthe surfaces of successive panel courses are aligned.Do not attempt to adjust the panel by using the crowbar on the front side - this can result in unacceptablechipping or spalling.

Check horizontal level. The horizontal level of eachpanel should be checked and adjusted in order to assurea uniform appearance and even joints throughout thestructure.

Figure 14

Use a 4-ft. level to verify that the new panel is level.Then sight back along the tops of the panels to ensurethat the new panel is at the elevation of the others in itscourse (Figure 14).

Correct any variations by lifting the panel slightly andinserting rubber shims in the horizontal joint below.Recheck the horizontal spacing after any suchadjustment.

Figure 15

Set batter. Panels must be given a slight batter, or tilt,toward the backfill in order to compensate for asubsequent outward movement which occurs duringbackfill placement and compaction. This movement willtend to push the panel to a true vertical position.Measure batter using a 4-ft. level (Figure 15).

Set the batter by adjusting the panel using a crowbar from the fill side (Figure 13). A combination of bracing,shimmed clamps, and wedges are used to maintain thebatter (Figures 19, 20, and 21).

Note that wooden wedges should remain in placeduring the erection of three subsequent coursesbut then must be promptly removed. If wedges areleft in place for more than three courses, removalwill be difficult and spalling can occur.

Care should be taken to assure that the panelremains centered and properly located until it hasbeen aligned, battered and clamped.


12/21


The amount of batter varies and depends on the type of backfill, moisture content of the backfill, requiredcompaction, type of compaction equipment, and lengthof the reinforcing strips. A batter of in 4 ft. isgenerally used as a starting point. Coarse backfills, suchas crushed stone, may require less batter, while finebackfills, such as sand, may require more.

Monitor the actual movement of panels during theplacement and compaction of each lift of backfill; adjustthe amount of batter according to field conditions.

Vertical Alignment Check. During construction, check the overall verticality of the structure daily using a plumbbob. By adjusting shims, bracing, and wedges, makeany changes in batter necessary to assure that finalverticality is within tolerances (see Specifications).

ERECTION TOLERANCES

The overall vertical alignment tolerance, or plumbness, from top to bottom of the structure,should not exceed in. per 10 ft. of height.

Vertical and horizontal alignment tolerance, or plumbness, should not exceed in. when measuredwith a 10 ft. straight edge on a selected wall section.

Vertical and horizontal alignment should bechecked at every course throughout the erectionprocess.

The maximum allowable offset between any twopanels should not exceed one inch.

Horizontal and vertical joints should be uniform inappearance.

Corrective action should be taken immediately whenany of the above tolerances are exceeded.

A. FOUNDATION PREPARATION

STEP A-1, Excavation : Excavate the site to the depthand width specified on the Plans for the length of thesection to be built. Remove all unsuitable material andreplace it, as necessary, with compacted fill as directedby the Engineer.

If required by the Specifications and as directed by theEngineer, proof-roll the foundation to a density suitablefor the bearing pressure shown on the Plans. In theevent of an over-excavation of the sub-grade, thegradation, placement, and compaction of replacementmaterial must be approved by the Engineer.

Evaluation and approval of foundation suitability isthe responsibility of the Engineer. Any foundationsoils found to be unsuitable shall be removed andreplaced with material approved by the Engineer.The material shall then be compacted, as directedby the Engineer, to a density suitable for the appliedbearing pressure as shown on the Plans,Specifications, and Contract Documents.

Foundation evaluation and control are critical; thebehavior and performance of a Reinforced Earthstructure is largely dependent upon the foundationon which the reinforced volume is placed.

STEP A-2, Drainag e Syst em(s): Install drainagesystems as required by the Plans and Specifications or as directed by the Engineer.

STEP A-3, Level ing pad: An unreinforced, smoothfinish concrete leveling pad is formed and cast at each

foundation elevation. Leveling pads have nominaldimensions of 6 in. thick by 1 ft. wide and are cast usinga minimum 2,000 psi, 28-day compressive-strengthconcrete. Pads should cure for a minimum of 12 hoursbefore the setting of panels.

Leveling pads must be cast to the design elevations asshown on the Plans. The allowable elevation tolerancesare +0.01 ft. (1/8 in.) and -0.02 ft. (1/4 in.) at designelevation.

An improperly placed leveling pad can result insubsequent panel misalignment and decreased wall

construction productivity.

If the Plans call for the structure to have a step-up inelevation, pour the higher leveling pad as indicated onthe Plans. Leave a 9-in. gap between the higher padand the centerline of the joint of the last panel of thelower course (Figure 16).

STEP A-4, Wall Line: Snap a chalk line on the levelingpad to establish a control line for the face of thestructure.

B. ERECTING THE INITIAL PANEL COURSE

STEP B-1, Panel Placement: Panel layout usuallybegins at the lowest leveling pad (Figure 17). Place thefirst panel [1] on the leveling pad. This may be a full or half height panel. Check the horizontal level of the paneland shim as necessary. Align the face of the panelalong the chalk line; and, using bracing and woodenwedges, set the batter of the panel.


13/21


Begin bracing the initial course of panels by securelyattaching two adequate lumber braces to each full paneland to any panel in excess of 3 ft. in height. A singlebrace may be used on panels 3 ft. in height or less(Figures 18 and 19). Bracing should be used onsubsequent courses when possible.

Figure 16

Figure 17

Throughout construction it is of utmost importancethat the panel type and number of tie strips of eachpanel match the requirements as shown on theapproved Plans.

Figure 18

Figure 19

Horizontal joint filler materials (i.e. Bearing Bloks) arenot used under the first course of panels on the levelingpad, unless specifically shown on the Plans or separately authorized in writing by The Reinforced EarthCompany. If needed, rubber shims may be used to shimbetween the leveling pad and first course of panels.Permanent wood shims are not permitted at any locationin the structure.

Panels must be braced as shown in Figures 18 and19 prior to releasing the crane from the panel.Bracing must remain in place until all braced panelshave had reinforcing strips attached and have beenbackfilled and compacted up to the top of thebraced panels.


14/21


Panels should be free of any surface defects that mayoccur in transportation, unloading, or storage at theconstruction site, including:

Cracked or broken corners. Permanent stains on exposed face. Cracks in a panel's surface.

Any repairs to panels must be completed to thesatisfaction of the Engineer.

STEP B-2: Place the second panel [2] on the levelingpad and place a spacer between it and panel [1](Figure 11). These spacers should remain in place untilthe wall is backfilled to the height of the half size panels.

Spacers must be used during panel erection.Spacers are supplied by the Contractor and may befabricated from any available material.

Figure 20

Figure 21

STEP B-3: Set the panel's batter as before. Clamp thepanel to panel [1] as shown in Figure 20. Tighten clampssufficiently to hold the panel in position withoutmovement.

Wooden wedges may be used at the base of the panelsto temporarily set batter in the initial course of panels.These wedges must be removed during subsequentconstruction.

STEP B-4: Place a third panel [3], aligning the panelwith the control line and using a spacer to ensurespacing. Check the horizontal level of the panel andshim as necessary. Set the panel's batter.

STEP B-5: Continue setting panels in this manner andsite back along the tops of the full height panels toassure that each new panel is at the elevation of theothers in that course .

STEP B-6: After ten panels have been set, recheck thewall's alignment by sighting along the wall face. Adjustpanels if needed to obtain a true line.

C. JOINT MATERIALS

STEP C-1: Joint materials prevent the loss of finebackfill particles while allowing the wall facing to be freedraining. Bearing Bloks prevent concrete-to-concretecontact between the facing elements.

Joint materials are installed only from the backfill side of the structure (Figure 22).

Figure 22

Filter cloth (if required) is affixed using several dabs of acontact adhesive to the backfill side of both the verticaland the horizontal panel joints.


15/21


The placement of horizontal joint material (BearingBloks), with regard to thickness and/or quantity atvarious levels within the structure, must be in strictaccordance with the Plans.

D. BACKFILLING

The constructibility and performance of a ReinforcedEarth structure are directly related to the quality of theSelect Granular Backfill and to the manner in which it isinstalled.

Prior to placing the Select Granular Backfill, theContractor shall certify to the Engineer that the materialconforms to the requirements stated in the Plans,Specifications, and Contract Documents for ReinforcedEarth structures.

Select Granular Backfill material to be used in thereinforced volume must strictly conform to theSpecifications. Material which does not conform

cannot be used as Select Granular Backfill.

STEP D-1: Place and compact initial lifts of SelectGranular Backfill up to bottom row of panel tie strips(Figure 23). Note that the uniform loose thicknessplacement of each lift of backfill material must notexceed 10 inches. The level of the compacted backfillshould be 2 in. above the tie strips and sloped asshown in Figure 24. Note that in order to avoid pushingthe braced panels out of alignment, initial lifts of backfillare neither placed nor compacted against the back of the panels.

Only after the first layer of reinforcing strips has beenconnected to the panel tie strips as detailed in Section E- and a lift of backfill placed and compacted over thestrips - can backfill then be placed and compactedagainst the back of the panels as illustrated in Figure 25.

Compact each backfill lift using a large smooth-drumvibratory roller except within a 3 ft. zone directly behindthe panels where a small hand-operated vibratorycompactor must be used to avoid undue panelmovement. Check wall alignment visually and with alevel; adjust panels as necessary.

The gradation of the Select Granular Backfill should betested periodically during construction to assurecompliance with the Specifications. This gradationtesting should be performed at least once for every2,000 cubic yards of material placed and/or whenever the appearance or behavior of the material noticeablychanges.

Figure 23

Figure 24

Figure 25

Immediate gradation and moisture testing isrequired if either excessive panel movement or backfill pumping occurs during construction.

STEP D-2, Compact ion : Large smooth-drum vibratoryrollers are used to accomplish mass compaction of Select Granular Backfill materials, except for fineuniform sands.

Sheepsfoot Rollers are never to be used for


16/21


compaction of Select Granular Backfill.

Within a 3 ft. zone from the back of the panels, smallsingle- or double-drum walk-behind vibratory rollers, or walk-behind vibrating plate compactors, must be used toprevent misalignment of the panels.

Compaction within 3 feet of the back face of panels

shall be achieved by at least three passes using alightweight mechanical tamper, roller or vibratorycompactor. Testing compaction in this zone is notrequired.

Fine uniform sands which contain more than 60 percentpassing a No.40 sieve used for Select Granular Backfillmust be compacted using a smooth-drum static roller.

Vibratory compaction equipment should not beused to compact fine uniform sands.

At a minimum, Select Granular Backfill material must becompacted to 95% of maximum density, per AASHTOT-99, methods C or D (with oversize correction asoutlined in Note 7).

Placement moisture content of Select Granular Backfillmaterial should be less than the optimum moisturecontent.

If 30% of the Select Granular Backfill material isgreater than 3/4 in. in size, AASHTO T-99 is notapplicable. For such material, the acceptancecriterion for compaction is either a minimum of 70%

of the Relative Density of the material as determinedby ASTM D-4253 and D-4254, or a MethodSpecification based on a test compaction sectionwhich defines the type of equipment, lift thickness,number of passes of the specified equipment andplacement moisture content.

The minimum frequency of compaction testing shallbe one test per lift of Select Granular Backfillmaterial placed. Test locations are determined bythe Engineer.

STEP D-3, Grading: At the end of each day's work,backfill must be graded to slope away from the back of the panels in order to divert water runoff from thestructure area.

Failure to properly grade the backfill can result inexcessive water in the Select Granular Backfill andcause subsequent movement of the panels beyondalignment tolerances.

E. REINFORCING STRIPS

STEP E-1: Place reinforcing strips on the compactedbackfill. Position strips perpendicular to the facingpanels, unless shown otherwise on the Plans.Reinforcing strips are supplied in lengths as shown onplans, with a tolerance in length from 0" to +8".

Connect each reinforcing strip to the embedded paneltie strips by inserting the end of the reinforcing strip intothe gap between the two exposed ends of the tie strip(match the three holes), pushing a bolt through the holesfrom below, placing a washer on top, threading on a nut(Figure 26), and tightening. Bolts must fit up throughboth tie strip flanges, perpendicular to the steelsurfaces, and have full bearing of the bolt head andwasher/nut against the tie strip flanges. Use a crescentor socket-head ratchet wrench to securely hand tightenthe nut.

Figure 26

Reinforcing strips should be placed perpendicular to theback of facing panels. In specific, limited situations itmay be necessary to skew a reinforcing strip from itsdesign location (perpendicular to the facing panel) ineither the horizontal or vertical plane.

Design of the Reinforced Earth structure is basedon the perpendicular placement and connection of reinforcing strips and on installation of the correctdensity and length of strips to each panel, unlessotherwise detailed on the Plans.

The placement of any reinforcing strip in a skewedmanner, unless shown on the Plans,Specifications, and Contract Documents, must beauthorized in writing by The Reinforced EarthCompany prior to placement in the field.

STEP E-2: Place backfill to the full height of the half panels (Figure 25). Dump backfill onto the reinforcingstrips so that the toe of the backfill pile is 3-4 ft. from the


17/21


panels. Spread backfill by pushing the pile parallel to thepanels and windrowing it toward the panels and towardthe free ends of the strips (Figure 27). If strips are long,a second load may be required to backfill to the ends of the strips. If so, dump and spread this load only after spreading the first.

Metal tracks of earthmoving equipment must never

come in contact with the reinforcing strips.Rubber-tired vehicles, however, can operatedirectly on the exposed strips if backfill conditionspermit and care is exercised.

Figure 27

STEP E-3, Step-up: If required, make a step-up inelevation at this point, using the following procedure.

Snap a chalk line on the upper leveling pad to establisha wall-face control line. Place a panel on the controlline, using a spacer to establish the proper distance fromthe last panel of the lower course. Set the panel's batter (Figure 28).

Continue construction of the upper course using theprocedure used on the lower course.

F. CONSTRUCTING SECONDAND SUBSEQUENT COURSES

STEP F-1: Only after backfill has reached the top of thehalf panels can construction of the second course begin.Throughout construction, panels should only be set after backfilling and compaction to grade have beencompleted.

Figure 28

Removing the clamps from a panel, or placing any

panel atop a panel, which has not been completelybackfilled, can create an unstable situation, lead tomisalignment of panels, and is strictly prohibited.

Begin the second and subsequent courses of panels atthe end of the wall where construction began(Figure 29).

Figure 29

STEP F-2: Remove the clamp holding the full heightpanels [1] and [3] to the half height panel [2]. (As eachcourse proceeds, remove only two clamps at a time toallow for setting of each new panel. Clamps should not be removed prior to complete backfilling of the affected

panels .) To prevent concrete-to-concrete contact athorizontal joints, set four Bearing Bloks onto the topedge of panel [2].

STEP F-3: Set the full height panel [101] onto the half height panel [2] (Figure 29), centering the panel toensure equal vertical joints and matching the panel'sfront face to that of panel [2]. Set the batter of the panelas for the panels of the first course and clamp the fullheight panel [101] to the initial course panels [1] and [3].

STEP F-4: Remove the next pair of clamps; place


18/21


horizontal joint material onto the half panel [4]; and setthe full height panel [102] onto it. Center the panel toassure equal vertical joints . Match the face of the panel

just placed to that of the panel below, and set its batter.Clamp the panel [102] to adjacent panels [3] and [5].

Continue to set full height panels in the same sequence. As work proceeds, check the wall's alignment frequently.Install joint material as in Step C-1.

STEP F-5: When the course of panels is complete andafter vertical joint material has been installed, placebackfill in lifts according to the Plans, Specifications,and Contract Documents up to the tie strip level. Figure30 illustrates the sequence for backfilling the secondand subsequent courses.

STEP F-6: After backfilling, recheck the batter andalignment of the wall, then place and connect the nextlayer of reinforcing strips as in Step E-1.

STEP F-7: Backfill up to the top of the full height panelsof the initial course. Bracing of the initial course can nowbe removed.

If after backfilling to the top of the full height panels,panels of the initial course did not become almostvertical, or if panels have gone beyond the vertical,adjust the amount of batter in the second course so thatthe second row will become vertical after backfilling.

At this point, placement and compaction of part or all of a berm or an embedment at the lower front surface of the structure can begin. Removal of the spacers at the base of the wall must be complete prior to placing this material (Figure 31).

Reinforced Earth structures with a leveling pad at or above existing grade require placement of an earthberm as toe protection along the face. Structures with aleveling pad below existing grade require the placementof an embedment in front of the wall.

The height of the berm or the depth of the embedmentis shown on the Plans.

The berm or embedment must be placed immediately toprevent erosion and before the wall reaches 50% of its

height.

STEP F-8: When backfill reaches the top of the initialcourse of full panels (which is halfway up the secondcourse), begin placing the next course of full panels.

Repeat Steps F-1 through F-5 for panel installation,backfill placement and compaction, reinforcing stripinstallation, and placement of horizontal/vertical jointmaterials. Follow these same procedures for the secondand subsequent panel courses until the structure isready to be topped off. Bracing should be used on all

subsequent courses, if practical, to assist withmaintaining batter and wall alignment as well asproviding additional stability to the structure during theconstruction process.

Figure 30


19/21


Figure 31

After the erection of each course of panels, the woodenwedges of that course and the two courses below itshould be checked to ensure that they are securelyseated.

Panel batter should be checked after backfilling eachcourse with necessary adjustments made to ensureplumbness.

At least two, but no more than three rows of panelwedges should remain in place at all times duringerection. When construction is complete, allwedges must be removed.

Quality control requirements for Select Granular

Backfill, including density and placement moisturecontent, are the same for the second and subsequentcourses as for the first course, unless otherwiseindicated in the Plans Specifications.

G. COMPLETION OF WALL

STEP G-1: In placing the top course of panels, theconstruction sequence continues as previously outlined.However, top course panels may have either a flat or asloping top edge and may be supplied in varying heightsto meet finished-elevation requirements.

Refer to the Plans and Specifications for the location of specific top panels.

STEP G-2: After backfilling is complete, remove allclamps and wooden wedges from the structure.

STEP G-3: Install top of wall treatment, if required.Several types are commonly used:

Cast-in-place. Necessary attachment details,frequently including a barrier, coping, parapet, or pavedditch, will be shown on the Plans. If required, rebar for connection will protrude from the top panels.

Precast Coping. If required, precast coping will besupplied. Attachment details will be shown in the Plans.


20/21


VI. CONDITION-CAUSE RELATIONSHIPSReinforced Earth structures are to be erected in strict compliance with the structural and aesthetic requirements of thePlans, Specifications, and Contract Documents. The desired results can be achieved through the use of quality materials,correct construction procedures, and proper inspection. However, considering the nature of construction work, there maybe occasions when dimensional tolerances and/or aesthetic limits are exceeded. Corrective measures must be takenimmediately to return the structure to acceptable tolerances.

Below are several examples of these condition-cause relationships.

CONDITION

1. Distortion in wall:

(a) Differential settlement or low spot in wall. (b) Overall wall leaning. (c) Panel contact, resulting in spalling/chipping.

2. (a) First course difficult to set and/or maintain level. (b) Panel-to-panel contact resulting in spalling and/or chipping.

3. Wall leaning out.

4. Wall leaning in.

5. Wall out of horizontal alignment tolerance, or bulging.

6. (a) Panels do not fit properly in their intended locations. (b) Subsequent panels are spalling or chipping.

CAUSE

1. Foundation (subgrade) material too weak or wet for proper bearing. If fill material, poor quality or improper compaction.

2. Leveling pad not within tolerance.

3. (a) Panels not battered sufficiently. (b) Large backfill placing and/or compaction equipment working within 3 ft. zone of back of wall. (c) Backfill material placed wet of optimum moisture content. (d) Backfill contains excessive fines materials (beyond the Specifications for percent of materials passing a No.200 sieve). (e) Backfill material pushed against back of wall before being compacted on strips. (f) Excessive or vibratory compaction on uniform

fine sand (more than 60 percent passing a No.40 sieve). (g) Backfill material dumped close to free end of reinforcing strips, then spread towards back of wall, causing bulge in strips and pushing panel out. (h) Wedges not seated securely. (i) Clamps not tight. (j) Excessive compactive effort. (k) Excessive lift thickness. (I) Plasticity index of backfill material in excess of specification limits.

4. (a) Excessive batter set in panels for Select

Granular Backfill material being used. (b) Inadequate compaction of backfill.

5. (a) See causes 3c, 3d, 3e, 3f, 3g, 3l. (b) Backfill saturated (heavy rain or improper grading of backfill after each day's operations).

6. (a) Panels are not level. (b) Differential settlement (see Condition 1). (c) Failure to use spacers between panels.

(d) Leveling pad incorrect.


21/21

VI. SAFETY TIPS UNLOADINGREINFORCED EARTH PRODUCTS

1. Upon arrival of truck, examine the load for any shifting or unstable conditions prior to removing tie downs.

2. The truck should be on level ground when unloading. Unloading on unlevel ground could result in shifting of panels or possibly panels falling from trailer.

3. Lifting equipment (straps, cables, ring clutches, etc.) should be checked for excessive wear or cracking prior to unloading truck.

4. Do not move the tractor while product is not tied down.

5. If drivers are required to remove chains or binders next to lane of moving traffic, cones and flagmen shouldbe used to direct traffic away from the trailer and driver.

6. Drivers are not trained as riggers or swampers and should stay in cab or clear away from unloadingoperations. The drivers are acting in a delivery capacity only.

7. Personal protective equipment required by the general contractor on site should also be required of deliverydrivers.

8. Personnel should not be allowed under a suspended load.

9. Once removed from the trailer, panels not placed directly in the wall should be stacked or secured on flatground to prevent tipping or falling.

10. Areas between the truck and crane should be restricted to personnel required to unload trailer.

11. If any unsafe situations exist while loading or unloading RECo products, contact The Reinforced EarthCompany immediately to eliminate any hazards or exposure to illness or injury.

The Reinforced Earth Company OfficesThe Reinforced Earth Company maintains full-service regional offices throughout the United States.

Contact the office serving your area for technical assistance.

Atlanta (770) 242-9415 Dallas (817) 283-5503 Seattle (425) 391-0111

Boston (978) 664-2830 Lake Forest (949) 587-3060 Vienna, VA (703) 821-1175

Chicago (630) 898-3334 Orlando (407) 240-3257

Corporate HeadquartersThe Reinforced Earth Company

8614 Westwood Center Drive, Suite 1100Vienna, Virginia 22182-2233

Telephone: (703) 821-1175 (800) 446-5700Telefax: (703) 821-1815 http://www.reinforcedearth.com
http://www.reinforcedearth.com/http://www.reinforcedearth.com/