Constructability Report drainage 26 02 13-ak (3) DB-r1 (Final) · PDF fileLusaka Water Supply, Sanitation and Drainage (LWSSD) Project Detailed Engineering Design and Tender Documents

THE REPUBLIC OF ZAMBIA MINISTRY OF LOCAL GOVERNMENT AND HOUSING

LUSAKA CITY COUNCIL

In Financial Cooperation with

Lusaka Water Supply, Sanitation and Drainage (LWSSD) Project Detailed Engineering Design and Tender Documents for Drainage Projects

CONSTRUCTABILITY REPORT

February, 2013

Lusaka Water Supply, Sanitation and Drainage (LWSSD) Project

Detailed Engineering Design and Tender Documents for Drainage Projects

Submitted to:

USACE Europe District

Millennium Challenge Corporation

H.P. GAUFF INGENIEURE GmbH & Co. KG

Passauer Strasse 7

90480, Nuernberg, Germany

26 February 2013

USACE Europe District

ATTN: Wayne Uhl

Konrad-Adenauer Ring 39

65187 Wiesbaden, Germany

Millennium Challenge Corporation

ATTN: Himesh Dunghel

875 Fifteenth St. NW

Washington, DC 20005-2221

Re: Lusaka Water Supply, Sanitation and Drainage (LWSSD) Project

Detailed Engineering Design and Tender Documents for Drainage Projects

Constructability Report

Dear Mr Uhl and Mr Dunghel:

We are pleased to submit the above referenced report under Task Order W912GB-12-D-0019-0011. This report details the constructability issues and the construction schedules as per the scope of the Task Order.

Please do not hesitate to contact us if any clarifications or additional information are required.

Yours faithfully

Stefan Dörner

Program Manager


Detailed Engineering Design and Tender Documents for Drainage Projects Constructability Report

Gauff Ingenieure Page I

LUSAKA WATER SUPPLY, SANITATION

AND DRAINAGE (LWSSD) PROJECT

DETAILED ENGINEERING DESIGN AND TENDER DOCUMENTS,

FOR DRAINAGE PROJECTS

CONSTRUCTABILITY REPORT

Table of Contents

1. BACKGROUND ................................................................................................................. 1-1

1.1 Scope of this Report ........................................................................................................... 1-1

1.2 Aims and Objectives of the Constructability Report ........................................................... 1-2

1.3 Organisation of the Report ................................................................................................. 1-3

2. DESCRIPTION OF THE DRAINAGE SYSTEM AND WORKS ......................................... 2-1

2.1 Description of the Bombay Drainage System ..................................................................... 2-1

2.2 The Main Features of the Existing Drains .......................................................................... 2-3

3. RECOMMENDED PACKAGING OF CONSTRUCTION CONTRACTS ............................ 3-4

3.1 Packaging Rationale .......................................................................................................... 3-4

3.2 Contract Package 1 – LD 1 : Improvement of Bombay Drainage System (north) .............. 3-4

3.3 Contract Package 2 – LD 2 : Improvement of Bombay Drainage System (south) ............. 3-5

3.4 Drain Lengths ..................................................................................................................... 3-5

3.5 Culverts .............................................................................................................................. 3-6

3.6 Rectangular and Covered Drains ....................................................................................... 3-7

3.7 Safety Fencing ................................................................................................................... 3-7

3.8 The Main Components of the Works .................................................................................. 3-8 3.8.1 Construction Works for Drains ......................................................................................... 3-12 3.8.2 Minimum Space requirement for Construction ................................................................. 3-13

3.9 Summary of Value of Components .................................................................................. 3-18

4. SUMMARY OF CONSTRUCTABILITY CHECKLISTS ..................................................... 4-1

5. PROJECT CONSTRUCTION SCHEDULE ........................................................................ 5-1

5.1 Contract Package LD1- Improvement of Bombay Drainage System (north) ...................... 5-1

5.2 Contract Package LD 2 – Improvement of Bombay Drainage System (south) .................. 5-1



Gauff Ingenieure Page II

Index of Tables

Table 2-1: Description of Bombay Drains ...................................................................................... 2-1 Table 2-2: Main Works ................................................................................................................... 2-3 Table 3-1: Lengths of the Drains .................................................................................................... 3-6 Table 3-2: Summary of Culverts .................................................................................................... 3-6 Table 3-3: Summary of Rectangular and Covered Drains ............................................................. 3-7 Table 3-4: Installation of Safety Fencing ........................................................................................ 3-8 Table 3-5: Summary of the Main Components of the Works ......................................................... 3-8 Table 3-6: Effect on Businesses or Property ............................................................................... 3-18 Table 3-7: Value Bracket Cost Ranges ........................................................................................ 3-19 Table 3-8: Value Bracket of Design Packages ............................................................................ 3-19 Table 4-1: Constructability Checklist Summary Table ................................................................... 4-1

Index of Figures

Figure 2-1: Alignments of the Bombay Drainage System .............................................................. 2-2 Figure 3-1: Boundary between the Proposed Contract Packages ................................................. 3-5 Figure 3-2: Map Showing Main Works: Package LD1 ................................................................. 3-10 Figure 3-3: Map Showing Main Works: Package LD2 ................................................................. 3-11 Figure 3-4: Work in Open Spaces ................................................................................................ 3-14 Figure 3-5: Work along Existing Roads ....................................................................................... 3-15 Figure 3-6: Works in Constricted Areas ....................................................................................... 3-16 Figure 3-7: Compact Skid Steer Excavator .................................................................................. 3-17 Figure 3-8: Compact Skid Steer Dumper ..................................................................................... 3-17



Gauff Ingenieure Page III

Annexes

Annex I Constructability Check List

Annex II Work Programmes

Annex II-1 LD1

Annex II-2 LD 2



Gauff Ingenieure Page IV

Acronyms and Abbreviations

AE Architect-Engineer (the Consultant: HP Gauff Ingenieure GmbH)

BoQ Bill of Quantities

BS British Standard

CBD Central Business District

ESIA Environmental and Social Impact Assessment

ESMP Environmental and Social Management Plan

GRZ Government of the Republic of Zambia

LCC Lusaka City Council

LCC-WMU Lusaka City Council Waste Management Unit

LSKA Lusaka Karstic Aquifer

RAP Resettlement Action Plan

RCOI Resettlement Corridor of Impact

USACE United States Army Corps of Engineers

USD United States Dollar

ZESCO Zambia Electricity Supply Corporation



Gauff Ingenieure 1-1

1. BACKGROUND

The Government of the Republic of Zambia (GRZ) has identified access to clean and safe water supply and adequate sanitation, drainage system and solid waste management in the Capital City of Lusaka as key priorities and have worked with the Millennium Challenge Corporation (MCC) to develop priority projects to be funded by MCC. The priority sub-projects were identified in the “Investment Master Plans” for water supply, sanitation and drainage financed by the MCC.

MCC and GRZ have agreed and signed a Compact program that focuses on the improvement of drainage infrastructure in order to reduce the adverse effects of flooding in parts of the Capital City of Lusaka.

The Lusaka Water Supply, Sanitation and Drainage (LWSSD) project covers the engineering design and tender documentation to source contracts for the drainage projects.

1.1 Scope of this Report

The scope of this report, as required by the Statement of work, is as follows:

The AE shall prepare and submit a Constructability Report that includes the following elements:

Packaging of Construction Tender Documents

The AE shall investigate and report the potential to combine or split sub-projects into manageable tender packages to achieve the following goals:

Minimize impacts to the local population to the extent possible, including minimizing disruptions to existing utility services, combining water and sewer projects in concurrent locations so that road excavation only occurs once; and,

Completion of all construction projects within the Compact timeline.

Sub-projects should be split or combined into manageable tender sizes that maximize the number of concurrent contractors to allow for multiple parallel projects, and focusing each contractor’s efforts on a particular geography.

Mitigation Strategy for Difficult Construction Conditions

AE shall identify strategies to develop specific language for consideration and inclusion in the tender documents to protect MCC and MCA-Zambia from cost escalation and construction overruns due to rainy season construction and drainage, flooding, and unsuitable conditions in the project areas. Include a section on rock construction, dewatering and blasting methodology or specialized equipment required to construct the works.

The SoW further states that:

The Constructability Report details the interactions of the sub-projects, defines overlapping project areas and presents a construction schedule demonstrating that the work designated can be reasonably accomplished within the Compact timeline. This document shall be presented prior to the draft tender documents.




1.2 Aims and Objectives of the Constructability Report

The aims of the constructability review process are to:

1. Enhance Early Planning

2. Minimize Scope Changes

3. Reduce Design Related Change Orders

4. Improve Contractors Productivity

5. Develop Construction-Friendly Specifications

6. Enhance Quality

7. Reduce Delays/Meet Schedules

8. Improve Public Image

9. Reduce damage to other utilities

10. Promote Construction Safety

11. Reduce Conflicts/Disputes

12. Reduce resettlement costs

13. Decrease Construction/Maintenance Costs

The constructability review process should assure that:

The project, as detailed in the plans and specifications, can be constructed using standard construction methods, materials and techniques

The plans and specifications provide the contractor with clear, concise information that can be utilized to prepare a competitive, cost-effective bid

The work when constructed in accordance with the plans and specifications will result in a project that can be maintained in a cost-effective manner by LCC over the life of the project




1.3 Organisation of the Report

This chapter introduces the broad project ‐ its background and objectives.

Chapter 1: Introduction

This chapter describes the works contained in the two design packages that are envisaged to be most appropriate for the current assignment. The purpose is to summarise the works included in each so that similarities in works and geographical location can be easily identified.

Chapter 2: Description of the Works

This chapter uses the information in Chapter 2 to make recommendations for merging and breaking up the works contained in the design package into logical construction contract packages.

Chapter 3: Recommended packaging of Construction Contracts

This Chapter contains the summary of constructability review of the design package. This is a checklist based review with summary tables of the major issues affecting each component of the project.

Chapter 4: Summary of Constructability Checklists

This chapter gathers the information on construction packaging and constructability issues and utilises it to recommend contract time scales for each construction package. Constraints on scheduling for each package are highlighted and a construction programme of work is presented for each contract package.

Chapter 5: Project Construction Schedule




2. DESCRIPTION OF THE DRAINAGE SYSTEM AND WORKS

2.1 Description of the Bombay Drainage System

The Bombay drainage system consists of the drains shown in the table below:

Table 2-1: Description of Bombay Drains

Item Nr

Item Description Chainage (Approx)

Features

1 Bombay Main 11.6 km The southern parts are mostly man-made while the north consists of the natural Ngwerere Stream

2 Bombay, Segment 2 5.2 km Most of this segment is man-made, is unlined and comprises road-side drains

3 Bombay, Segment 3 2.2 km Although the southern part of this segment is man-made, in its northern part especially it has thick vegetation growth. The point at which it is joined by the ZESCO link drain was originally the source of the Ngwerere Stream

4 Bombay, Segment 4 2.6 km A natural contributory stream that runs along the railway lines from west or south to east

5 Bombay, Segment 5 2.1 km A natural contributory stream that runs northwards along the railway line

6 Lumumba Drain North 6.3 km Man-made, lined runs towards the north and north east and joints Bombay Main.

6 Lumumba Drain South 3.2 km Man-made, lined runs in a southern direction. The flow is linked to the ZESCO Drain together with the flow coming from the south..

7 ZESCO Drain 0.91 km Man-made lined and covered runs towards the east and joins the southern part of Lumumba Drain to Bombay Main Drain

Note: The above chainages are approximate horizontal distances.

The Bombay Main drain flows from the south towards the north and then takes a north easterly direction to the outfall. En route, the Bombay Main Drain is joined by the 4 segments indicated above.

The Lumumba drain flows from two high points towards the south and towards the north. This drain runs along Lumumba Road and is in two separate parts – it is not joined between the two high points. The ZESCO Link Drain runs towards the east and joins the southern part of Lumumba Drain to Bombay Main Drain

The routes of the drains are shown in the Figure below.




Figure 2-1: Alignments of the Bombay Drainage System




2.2 The Main Features of the Existing Drains

The main objective of the works is to improve the drainage system in order to reduce the adverse effects of flooding in parts of Lusaka.

The description of the main works to improve the performance of the drains is given in the table below. The works will include excavations, filling and compaction, improvement of gradients, concrete lining of the drains, replacement of box culverts, installation of safety rails, covering of some drains, etc. The main works are stated in the table below:

Table 2-2: Main Works

Item

Nr

Item Description Chainage

(Approx)

Main Works

1 Bombay Main 11.6 km Substantial clearance of vegetation in the natural Ngwerere Stream part of the drain. Mostly trapezoidal sectioned drains with about 2.5 km of rectangular drains and about 706 m covered. Major road culverts – 16 nr, railway culvert – 1 nr.

2 Bombay, Segment 2 5.2 km Mostly trapezoidal sectioned drained a small section

of about 311 m of uncovered rectangular drains.

Large number of culverts (23 nr) of sizes from 2x1.5

m single to 7 nr 2.4x2.4 m double and 1 nr 3x1.8 m

3 Bombay, Segment 3 2.2 km This segment is also largely trapezoidal with about

340 m of open rectangular drains and 4 box culverts,

the largest being 3x2.4 m single, 1 nr

4 Bombay, Segment 4 1.8 km Natural stream runs along the railway line from south

west to south east direction. This will require

substantial vegetation clearance. Will require 4

culverts, the largest being 2x1.5 m single, and two

railway culverts.

5 Bombay, Segment 5 2.9 km Natural stream runs along the railway line towards

the north. This will require vegetation clearance.

There will be only 4 culverts, the largest being 2x 1.5

m, double.

6 Lumumba Drain

(North and South)

9.5 km Parts of this drain are heavily populated by traders.

About 3.0 km will be rectangular with about 1.0 km

covered. There will be 24 nr road culverts from 6 nr

2x1.5 m single, 5 nr 2.4x2.4 m double to 1 nr 3x1.8 m

and 1 nr. railway culvert.

7 ZESCO Drain 0.91 km This drain will be rehabilitated with repairs to the

manholes and internal structural repairs.

It is recommended that the packing be organised by dividing the project into two packages arranged geographically.

This packaging strategy is discussed below.




3. RECOMMENDED PACKAGING OF CONSTRUCTION CONTRACTS

This section of the report is intended to take the various design sub-projects above split them into two works contract packages of approximately equal duration of construction.

3.1 Packaging Rationale

The rationale used in selecting the works to go into each contract package is broadly as follows:

1. Where possible all works in one geographical area should be carried out by the same contractor. This minimises the amount of interaction and overlap between contractors and reduces the chance of them interfering with each other’s work progress.

2. Where possible all works that are co-dependent are included in a single contract. In this way the possibility of claims arising from a contractor due to the failure to perform by another contractor is minimised.

3. Works of a dissimilar nature, or size are generally kept in separate contracts unless they represent a small part of the contract and can be easily subcontracted.

With regard to these drainage works, the logical packaging is by dividing geographically. Two packages are recommended to enable one contractor to work on the larger works in the north and the other on the smaller works in the south and west.

Each contract will have all the works which are co-dependent apart from the point where the works of one contract will end and that of the other commence. It will be important for the supervising engineer to provide the two contractors the levels and other relevant information for such locations.

The recommended packages are discussed further below.

3.2 Contract Package 1 – LD 1: Improvement of Bombay Drainage System (north)

Contract package LD1 will include all of the works for the improvement of the drains in the north east as shown in Figure 3.1.This will include:

Bombay Main: From the culvert under the Great East Road northwards to and including the Trash Trap and the downstream footbridge;

Lumumba North: From the culvert under the Great North Road eastwards to the junction with Bombay Main;

Bombay Segment 3: the section north of the Great East Road;

Bombay Segment 4;

Bombay Segment 5;

Trash trap.

These works will also include the manufacture and installation of the trash trap components. Substantial earthworks will be required for the works in this package. Ground water and leakages from the interceptor sewer that runs adjacent to the natural watercourse along the southern edge of Mutambe and north of Chaisa, west of the Garden Pondswill require diversions.




3.3 Contract Package 2 – LD 2 : Improvement of Bombay Drainage System (south)

Contract package DLLD2 will include all of the works for the improvement of the drains in the north-west and towards the south, i.e.:

Bombay Main: south of the culvert under the Great East Road;

Lumumba Drain: west of the culvert on the Great North Road;

ZESCO Link Drain;

Bombay Segment 3: the section south of Great East Road;

Bombay Segment 2.

There will be limited disruption from ground water except possibly towards the end of a rainy season. Moderate amounts of rock excavation will be required.

The boundaries of the two packages and the areas covered are shown in the Figure below.

Figure 3-1: Boundary between the Proposed Contract Packages LD1 and LD2

3.4 Drain Lengths

The approximate lengths covered by each package are shown in the table below.




Table 3-1: Lengths of the Drains

Item

Nr

Item Description Package LD1 Package LD2

1 Bombay Main 6.6 km 5 km

2 Bombay Segment 2 0.0 km 5.2 km




6 Lumumba 1.5 km 8.0 km

7 ZESCO Link Drain 0.0 km 0.9 km

8 Total 14.1 km 20.3 km

Only rehabilitation works will be done on the ZESCO link drain.

3.5 Culverts

All the culverts were found to be under-sized and these will be required to be replaced both on the roads and major highways and four railway crossings. These culverts need to be S-Class portals in accordance with the current National Specification, except possibly for the four railway culverts that may have to be of the SAR-class to take the expected future rail loads. A summary of the culverts is provided below.

Table 3-2: Summary of Culverts

Item

Nr

Item Description Package

LD1

Package LD2

1a Bombay Main Road Culverts 8 nr 8 nr

1b Bombay Main Railway Culverts 0 nr 1 nr

2 Bombay Segment 2 Road Culverts n/a 23 nr

3 Bombay Segment 3 Road Culverts 2 nr 2 nr

4a Bombay Segment 4 Road Culverts 4 nr n/a

4b Bombay Segment 4 Railway Culverts 2 nr 0 nr

5 Bombay Segment 5 Road Culverts 4 nr n/a

6a Lumumba Road Culverts 2 nr 22 nr

6b Lumumba Railway Culverts 1 nr 0 nr

7 ZESCO Link Drain 0 nr 0 nr

8 Trash Trap 1 nr n/a

8 Total 1 – S Class Road Culverts 20 nr 55 nr

9 Total 2 – SAR Class Railway Culverts 3 1




A total of 75 nr S-Class road portals and 4, possibly SAR-class railway culverts will be required. The box culvert sizes vary from 1.5x1.5 m single barrel units up to 3.0x3.0 m triple barrel units on Bombay Main. The latter is under the Katima Mulilo Road. Most of the culverts on Lumumba Drain vary from 2.0x1.5 m single and 2.4x2.4 m double barrel, which are mostly in the northern section. Before the trash trap, 1 nr 3x3 m, triple barrel road culvert is envisaged under Kasangula Road.

In addition, approximately 380 C-Class portals or slabs for driveways and slabs for walkways will be required.

Although the total lengths and the number of culverts are greater for Package LD2, the investments will be about the same since Package LD1 includes the installation of the trash trap and also the earthworks in the north are more than in the south.

3.6 Rectangular and Covered Drains

Due to lack of space and in locations where there are public safety issues, covered rectangular drains are proposed. A summary of the total rectangular drains and the lengths of the covered drains is provided in the table below.

Table 3-3: Summary of Rectangular and Covered Drains

Item

Nr Item Description

Package LD1 Package LD2

Rectangular Covered Rectangular Covered

1 Bombay Main 1,051 m 0 m 1,456 m 749 m

2 Bombay Segment 2 n/a n/a 311 m 0 m

3 Bombay Segment 3 965 m 0 m 340 m 0 m

4 Bombay Segment 4 36 m 0 m n/a n/a

5 Bombay Segment 5 0 m 0 m n/a n/a

6 Lumumba 780 m 780 m 2,248 m 1,094 m

7 ZESCO Link Drain n/a n/a 910 m* 910 m*

8 Total 2,832 m 780 4,355 1,843

*’ Existing covered drain, not included in the total.

The lengths provided under the ‘Rectangular’ includes the covered drains, the lengths of the latter are shown separately.

3.7 Safety Fencing

Safety concrete post and rail fencing will be provided in areas of public accessibility where hazardous conditions will be present due either to the depth of the drains and/or where high velocities of flood water may be encountered.

The details are provided in the table below:




Table 3-4: Installation of Safety Fencing

Drain Location Package LD1

Drain Length

(m)

Package LD2

Drain Length

(m)

Bombay Main Kamwala Mkt n/a 736

Bombay Main Evelyn Hone College n/a 620

Bombay Segment 2 Evelyn Hone College n/a 104

Lumumba North nr Soweto Mkt n/a 1095

Lumumba North Timber Mkt 140 n/a

Lumumba North Section just north of Vubu Road 695 n/a

Lumumba North Mandevu Mkt 245 n/a

Bombay Main Garden South Compound 1330* n/a

Bombay Main Garden North Compound 2170* n/a

Bombay Main At and north of Kasangula Road 400 n/a

Total 4980 2555

Required on both sides of the drain

3.8 The Main Components of the Works

A summary of the main components of the works is presented in the table below where:

BM: Bombay Main Drain

BS: Bombay Segments (Segment 3. 4. & 5 for LD1 and 2 & 3 for LD2)

LM: Lumumba Drain

ZL: ZESCO Link Drain

Is a major component of the work

Is a minor component of the work

Is not included in the work

Table 3-5: Summary of the Main Components of the Works

Works Package Package LD1 Package LD2

Drains BM BS LM BM BS LM ZL

Work Item

Procurement

Foreign Procurement

Local Procurement

Dry Weather Diversion of Water

Attention to Other Utilities

Excavations

Class I Material

Class II Material

Class III Material





Drains BM BS LM BM BS LM ZL

Work Item

Filling and Compaction

Replacement of Box Culverts

Small Section

Medium Section

Large Section

Trash Trap

Drain Cross-Sections

Trapezoidal

Rectangular

Access Chambers

Safety Fences

Resettlement Issues

Land acquisition

Clearing of wayleaves

Compensation

Environmental

Hazardous Wastes

The Figures below show the locations of some of the more important works for Package LD1.




Figure 3-2: Map Showing Main Works: Package LD1

The Figures below show the more important locations of some of the works for Package LD2.




Figure 3-3: Map Showing Main Works: Package LD2




3.8.1 Construction Works for Drains

Drains

Almost all the drains exist in some rudimentary form although some realignment is necessary in the unimproved sections of the Bombay Main Drain north of its junction with segment 5, in segment 3 north of the Great East Road and the latter parts of the Lumumba North Drain, especially east of the Great North Road The improvement of the existing drains will entail the following works.

Drain Improvements

Diversion of dry weather flow via temporary gravity or pumped conduits. Where necessary use of temporary cofferdams and dewatering to provide dry work areas;

Confirmation of levels to ensure the required gradients;

Earthworks consisting of excavation of rock, reshaping and improvement of the gradients where required;

Attention to other utilities crossing the drains: raising, lowering or re-location if required;

Base of drains:

o Blinding layer to the base;

o Laying of the notched pre-fabricated base slabs;

Drain sides:

o Side trimming;

o Polythene sheeting for in-situ concreting of drain side walls;

o Free-draining material for drain side walls;

o In-situ concreting of the sides and incorporation of weep holes;

Most of the drains will be of trapezoidal section but rectangular drains will be constructed where limited space is available and also where covering is required.

Perennial dry-weather flow is predominant in the northern parts of the drainage system

Covers for Drains (3 m x 1.2 m)

Where covered drains are required, these will all be pre-cast and transported to site by a truck-complete with offloading crane.

Access Structures

Access structures will be provided to all covered drains at approximately 100 m centres to allow LCC to carryout periodic removal of solid waste

Safety Fencing

Along roadsides, concrete post and rail fencing will be provided on the side away from the road in areas where either drain depth or peak flow velocity is considered to warrant it. Through the Garden Compounds such fencing will be provided on both sides of the drain




while at and north of Kasangula Road, safety fencing will be provided on the western side of the drain as far as the trash trap.

3.8.2 Minimum Space requirement for Construction

Work in Open Spaces and Along Roads

The space required for construction, will vary depending on the width and type of drain,. Where space is available an additional 5 m is needed on one side of the drain for the movement of construction plant and 3.0 m on the opposite side for lay down, stockpile and general construction space. Therefore the working corridor required is 5.0 m + top width of drain + 3.0 m. In such open spaces, adequate room is required to allow trucks and plant to turn.

In open spaces and where the drains run parallel to existing roads, part of or up to one carriageway of the road may be used to provide the 5.0 m corridor for plant. Normal town roads are 6.0 m width plus shoulder. The 3.0 m on the opposite bank may still be required. These scenarios are illustrated in the Figures below for a typical trapezoidal drain of 3.0 m bottom width.

In open spaces and along roads the work can be done from the side of the drain. For this the following will apply:

Minimum width required as stated above;

Safety cones and barriers to cordon off the work area;

Excavation with a backhoe and truck for haulage;

Use of non-explosive blasting/jack hammer for rock excavation;

In-situ concreting by using concrete mix tanker, 8.0 m3;

Laying of pre-cast base slabs with a truck-mounted crane;

Spoil stock-piled within the 3 m width on opposite bank from plant;

To avoid double-handling, spoil should be preferably loaded to trucks, 8 t trucks.

Trucks and plant working along existing roads have the possibility to manoeuvre and, therefore, the width of a normal road (6 m) would be adequate.

For the main culverts on highways, pre-cast box culverts to S standard will be required. For this work, cranes of 5 t capacity will be required.

Work in open unrestricted spaces is illustrated in the Figure below.




Figure 3-4: Work in Open Spaces

The sketch below shows the recommended strategy for working along existing roads for a typical drain.




Figure 3-5: Work along Existing Roads on a Typical Drain

Work in Areas with Constricted Access

A different approach is required in areas where access is constricted due to the close proximity of boundary walls, buildings, and other structures. The RAP consultant will identify these locations. In many places it will be possible to work in constricted areas without removal of the constricting structures using the following methodology and equipment:

Work within the drain;

Safety cones or barriers to warn the public;

Excavation with a compact bobcat type of excavator. A typical excavator shown below has a width of 1.6 m width;

Such an excavator weighs less than ½ t and may be lowered into a drain by:

o A mobile crane if an access point is available before the constricted space or;

o By erecting a temporary overhead beam supported on 3 shear legs, one on each side of the drain and using a chain block for lifting and lowering;

In-situ concreting by using a dumper, 0.3 m3;

Laying of pre-cast base slabs with a manual mobile crane lowered into the drain as stated above;




The spoil may be removed either by:

o Load and carry away within the drain in dumpers to the open space for stock-piling and loading to the trucks;

o Stock-piled on the drain edge and carried out to the open space in wheel barrows or mini dumpers.

This procedure should considerably reduce resettlement costs.

The walls and structures encountered along the drains are of variable standard and many will have shallow and potentially unstable foundations. The works may damage these structures and make them unsafe. This needs to be considered on a case by case basis.

Constricted areas will be confirmed by the RAP Consultant and accurately marked in GIS, for the AE to inspect further to determine engineering integrity of the surrounding structures and confirm that contractors would be able to conduct operations efficiently in the constricted space, without damaging the structures

Works in constricted access areas are illustrated in the Figure below.

Works in constrained areas for a typical trapezoidal drain with a 3 m bottom width are illustrated in the Figure below.

Figure 3-6: Works in Constricted Areas on a Typical Drain

A typical compact excavator which can work in the drain in constrained areas is shown in the Figure below:




A Length with Bucket 3.2 m E Ground Clearance 0.20 m

B Width over Tyres 1.6 m F Length without Bucket 2.5 m

C Height to Top of Cab 1.9 m G Max Lift and Dump 2.2 m

D Wheel Base 1.0 m H Reach at max Dump 0.51 m

Figure 3-7: Compact Skid Steer Excavator

A typical mini dumper is shown in the Figure below. Such a dumper with a 0.3 m3 bucket may be used for removing the spoil and for carrying in-situ concrete for short lengths of drains in constricted areas. The width over the tracks for such a dumper is only 0.690 m. Other dimensions are provided below. The dumper and the excavator above weigh less than ½ t and may be lowered in to a drain as explained above.

A Length (Bucket Raised) 1.70 m E Skip Height 0.80 m

B Undercarriage Length 0.87 m F Overall Height 1.1 m

C Maximum Height 2.7 m I Maximum Width 0.69 m

D Ground Clearance 1.0 m Machine weight 475 kg Figure 3-8: Compact Skid Steer Dumper




Despite the above possibility, some areas where property or businesses may be affected are shown in the table below. The approximate drain lengths of the affected area are shown.

Table 3-6: Effect on Businesses or Property

Item

Nr Item Description Likely Affect

Package LD1

Drain Length (m)

Package LD2

Drain Length (m)

1 Bombay Main: Kamala Market: (A)

700 m

2 Bombay Main Between Church

Rd and Great East Roads

(B)

900 m

3 Bombay Main: Trash Trap Site (C)

50

4 Bombay Segment 2: Corner

between Chilimbulu and

Manshya Roads

(D)

100

5 Lumumba: nr Soweto Market (E)

1,100

6 Lumumba: Between Vubu and

Lumumba Roads

(F)

500

7 Lumumba: East of Great North

Road

(G)

250

8 Total

800 2,800

(A): Mainly temporary disruption of business activities

(B): Minor disruption to private property. Constrained area work;

(C): Compound walls in the flood plain to be demolished;

(D): Total Petrol Station. The forefront built on top of the drain. To be excavated and reinstated after the works to increase the drain cross-section

(E): Traders either on top of the drain or besides the drain. Traders will have to be relocated at least till the works are complete

(F): A number of driveway access slabs will have to be removed during the works and reinstated

(G): Mandevu market. Moderate disruption to businesses.

3.9 Summary of Value of Components

The client has expressed a preference that actual values not be included in reports for general circulation. Therefore the various packages have been assigned into value brackets as follows:




Table 3-7: Value Bracket Cost Ranges

Value Bracket Value Range

Medium

Large

Very Large

Using these brackets the design packages listed above can be categorised as follows:

Table 3-8: Value Bracket of Design Packages

Design Package Value Bracket

LD1 Very Large

LD 2 Very Large




4. SUMMARY OF CONSTRUCTABILITY CHECKLISTS

Annex I-1 contains a constructability checklist for both the proposed drainage construction packages. At this stage of the design process the works have not been sub-divided into construction Contract Packages so the Constructability checklist has been carried out on the total design package. The table below summarise key points from the checklists, where

BM: Bombay Main Drain

BS: Bombay Segments (Segment 3. 4. & 5 for LD1 and 2 & 3 for LD2)

LM: Lumumba Drain

ZL: ZESCO Link Drain

Works largely unaffected by issue

Works moderately affected by issue

Works significantly impacted by issue

Table 4-1: Constructability Checklist Summary Table


BM BS LM BM BS LM ZL

Issues

Long Procurement Lead Times

Location of Existing Utilities

Access to Working Areas

Weather Disruption (rains)

Dewatering and flow diversion

Geotechnical

Undefined geotechnical risk

Known rock occurrence (2 -3m)

Groundwater in excavations

Traffic Accommodation

Public road traffic

Public access disruption

Resettlement

Land Acquisition Required

Compensation for damage

Compensation for disruption







5. PROJECT CONSTRUCTION SCHEDULE

Time schedules have been developed for the two proposed contract packages. Key considerations and constraints in the scheduling of each component are given below. In addition to the specific programming requirements shown below the following general requirements have been applied:

1. The updated EAIAs and ESMPs will be submitted in May, 2013 and the final tender documents shall be delivered in August, 2013.

2. Contracts are, therefore, proposed to start by 1st February, 2014 to allow adequate time for bid invitations, bidding, evaluation and award. Also, in February the 2013-2014 rainy season can be expected to be coming towards its end.

3. Areas where resettlement and land acquisition compensation is to occur, construction will not be permitted until RAP implementation has been concluded in the area concerned.

4. At the commencement of the construction phase there are time allowances for mobilisation and procurement of materials. These have been applied as follows:

a. Local supply materials – the majority of the materials are available in Zambia and these will be procured as and when required

b. Foreign supply materials – the main materials that may have to be imported are S-Class road, and possibly SAR-class railway Culvert Portals, which are available in Zimbabwe but not yet in Zambia

5. It is assumed that the contractor will mobilise during the first 2 months of the contract and that there will be limited filed activity during this time.

6. The approximate periods of construction are provided below.

5.1 Contract Package LD1- Improvement of Bombay Drainage System (north)

On average 25 m of drains can be constructed per day. The total required months will be 25.6 dry months. With 8 dry months per year, a total of about 3.2 years will be required.

The installation of the trash trap could be done in parallel with the other works.

Pre-casting works can be carried on during each rainy season.

5.2 Contract Package LD 2 – Improvement of Bombay Drainage System (south)

The works in the south will require less earthworks and it is estimated that an average of 30 m per day of drain construction can be achieved. The total dry months required will be 29.4 and as shown above, with 8 dry months per year, a total of about 3.6 years will be required.

The work programmes envisaged are shown under Annex II-1 and Annex II-2


Preparation of Detailed Engineering Designs and Tender Documents for Drainage Projects, Lusaka, Zambia


Gauff Ingenieure

ANNEX I

Constructability Check List

Page 1

Drainage ‐ Constructability Checklist

Checklist Item Drainage Constructability Comments

1. GENERAL

1.1. Are areas available for:

1.1.1. Contractor’s camp and offices The drainage project extends over an area of about 8.5 km N‐S and 3 km W‐E.with 2 contracts proposed, one north and one south, Suitable commercial rental properties are available.

1.1.2. Materials stockpiles As above

1.1.3. Disposal of waste materials Non soil waste to be disposed in Council designated waste dump at Chunga, which is situated off Chitanda Road, about 5 km by road, north west of the trash trap site.

Topsoil and unsuitable materials that cannot be disposed of onsite shall be disposed of in gravel material borrow pits, subject to ZEMA approval.

1.2. Are the necessary skilled personnel available in the local market and where necessary will the contractor be able to bring in staff from outside the country?

Required trades are available within Zambia. Immigration rules allow for management staff and staff with specialist skills to be brought from outside the country

1.3. Do the works require the importation of any high value items of specialist nature? If so have alternatives that eliminate this need been considered?

If by the start of the contracts, Infraset in Zambia have still not started a new compliant production line for the pre‐cast S Class portal culverts these will come from Zimbabwe unless the contractor opts to pre‐cast his own.

Page 2


1.4. Will double handling of materials be involved?

Pre‐cast concrete units (if imported) would have to be delivered to the contractor’s storage areas. If from Infraset then they can in most cases be delivered directly to a specific works site. Alternatively, a Contractor may opt to pre‐cast his own units, possibly to occupy his skilled works personnel during the rainy season.

Steel reinforcement would be stockpiled at the contractor’s storage areas.

Any other special materials e.g. for the trash trap would probably be delivered first to the contractor’s storage area. Similarly for steel sections to fabricate the footbridges.

Mass concrete shall be mixed at contractor’s batching plant and transferred to the work sites for in‐situ construction

Earthworks materials and special bedding materials may be delivered directly to the point of use.

1.5. Is there space for stockpiling of materials?

Away from roads, space exists along the drain alignment for temporary storage of excavated material and dumping of special bedding materials

Along road sides excavated material should be transferred directly into haulage lorries and carted away.

Page 3


1.6. Are utility locations accurately defined?

Visible utilities (LWSC, ZESCO and ZAMTEL) have been accurately surveyed and utility crossing detail sheets produced for each to aid identification and a decision on relocation where necessary.

Locations of existing underground cables, pipes and sewers have been obtained from the relevant utility providers but are subject to confirmation by the Utility concerned.

1.7. Has the need for utility relocation been identified and have the costs been defined with the appropriate utility?

Some existing water pipelines will need to be realigned (raised or lowered).

Where sewers impede the drain section, the drain is to be widened locally to maintain the flow cross‐section.

Other non‐LWSC utilities are still subject to confirmation.

The estimated costs of realignment to be included in BoQs

To be agreed with the relevant Utility organisation

1.8. Access consideration

1.8.1. Are personnel work areas easily accessible?

All structures and work areas are readily accessible.

However in some areas away from roads temporary access tracks will have to be established especially in flood plains

1.8.2. Is there access for excavation plant?

Some sections are accessible only along or off the main roads. Several other streets are narrow because of market stalls constructed within the way‐leaves. These have left limited space for the drains.

Will be addressed under the RAP consultancy

1.8.3. Is there access for haulage trucks to all areas they need to dump?

No access constraints.

1.8.4. Are there traffic restrictions or congestion issues affecting site access?

Yes, especially in the City Centre where movement of materials to/from the sites will have to join the general traffic congestion.

Page 4


1.8.5. Are there measures available such as opening up temporary access routes that would considerably improve constructability?

Demolition of structures hindering access and severely constraining or preventing constructability has been provided for.

Providing temporary tracks from the nearest road within the flood plains

1.9. Will weather become a factor for the successful completion of the job?

All site operations become an issue in the heavy rainfall months of November to February.

In the lower, northern reaches, channel flow is perennial and provision for a dwf central channel within the drain bed and coffer damming and pumping or flexible tunular containment from up to downstream around the coffer dammed area during construction of the section concerned will be necessary.

Make allowances for reduced to nil productivity in these months in the project timescale in the Contract Document

1.10. Efficiency of construction

1.10.1. Are there non‐standard or complex methods of construction and could any of these be simplified?

Standard construction methods used in areas

with there is unrestricted wayleave.

In areas where wayleave width is limited due to

the presence of property boundary walls on

both sides, it will either be necessary to

demolish and after construction rebuild the wall

or use a non‐standard construction method

where the drain floor becomes the means of

accessing light plant, materials and workers in

order to construct in‐situ side walls.

1.10.2. Has construction sequencing been considered in the design?

Yes. Work will progress in an upstream direction along any drain section.

1.11. Construction efficiency in specification

Page 5


1.11.1. Are specifications adequate to meet functional requirements without being unnecessarily onerous which may introduce construction difficulties?

In general yes; however in some areas progressive site hand over to a Contractor will be necessary and he will be required to complete and hand back within a limited time period to allow commercial enterprises affected during construction to be subjected to minimum disruption.

Further review of specification at 90% design.

1.11.2. Have new items been introduced in the specifications/ method of measurement where standard items might suffice?

Method of Measurement, no. Specifications, yes, but only as far as necessary due to specific site related constraints.

1.11.3. Do the specifications contain any restrictive clauses regarding source of material or equipment or manufacturing standard which may reduce options for competitive pricing?

All materials etc. are specified in terms of functional requirements and appropriate Standards.

Where manufacturer’s names are used in the specifications or drawings, these are always suffixed with ‘or equivalent, or better’ to remove restriction whilst placing the emphasis on the contractor to demonstrate equality.

1.12. Are pay items in the bid tabulation apparent in the specifications and in the drawings?

A standard specification and method of measurement is used (CESMM) and new items only introduced where the work items are not covered by the standard.

Drawings will contain cross references to pay items where necessary.

Add cross references to drawings

Divide certain pay items in the BoQ such as concrete, earthworks etc. to indicate the location of the work

1.13. Are materials purchasing requirements simple to accurately extract from the Bill of Quantities?

CESMM bills use separate ‘supply’ and ‘install’ items for some elements.

Ensure ‘supply’ and ‘install’ quantities are consistent

Ensure drawings contain sufficient labelling and callouts to reference with items in the BoQ

2. EARTHWORKS

Page 6


2.1. Has the design been earthworks balanced to reduce the need for imported materials?

Where practicable, yes, although in general excavated material is considered unsuitable to be used as a well drained backfill due to its silt and clay content. However, in rocky areas and where the present natural drain section is larger than the final lined section, imported material for backfilling will be necessary.

2.2. Where imported materials are required is the specification appropriate to the requirement?

Yes. Details of quality of material for imported backfill are provided for in the specifications.

3. Drain Construction

3.1. Have the materials through which trenches are to be excavated been properly categorised?

Geotechnical investigations have characterised the materials along all proposed drain lines.

3.2. Have any potential areas of ‘hard’ or intermediate excavation been identified and have sufficient quantities of such excavation been allowed for in the BoQ?

Extra‐over excavation for areas with rock has been provided for in the BoQs.

Extent and depth of intermediate excavation material to be marked on profile drawings and cross referenced to geotechnical investigations

3.3. Are trenches stable to the required digging depths or is shoring required. Do the specifications and drawings indicate the areas where shoring is required?

Excavation for drains in deep sections will be trapezoidal in section as will the drain to be constructed. Shoring up of some boundary and building walls during construction in areas with limited wayleave width will however be necessary. Geotechnical investigations show reasonable stability throughout the areas, subject to the above noted provison.

3.4. Is groundwater likely to be encountered in any excavations?

Yes, especially in central and northern areas where the drain will largely follow natural stream beds where there is perennial dry weather flow.

Page 7


3.5. Is specialist equipment required and if so have alternatives been considered to eliminate the need for it?

Dewatering pumps may be needed in areas with perennial flow and together with sewer stoppers for the old, life expired Interceptor Sewer section adjacent to the last section of the Lumumba drain that is leaking and prone to burst.

3.6. Is rock likely to be encountered and has provision been made in the designs?

Yes. Extra‐over excavation for areas with rock has been provided for in the BoQs.

3.7. Is rock blasting possible or are alternative measures for rock removal required?

Non‐explosive rock blasting is recommended where rock is encountered.

Specifications will clearly state where non‐explosive rock blasting is required and what type is acceptable (e.g. fractac, gas system, etc.)

4. STRUCTURES

4.1. Are founding conditions suited to the structure foundation design?

Yes. The ground conditions are suitable for the construction of the works, although in some flood plan areas it may be necessary to import granular backfill material to place below the structure.

4.2. Is sufficient working space available for structural works?

An existing boundary wall, illegally constructed within the flood plain will need to be demolished for the trash trap. Illegal structures such as walls are known to have been constructed across drains in a few areas.

Will be addressed under the RAP consultancy

5. MECHANICAL

5.1. Is mechanical equipment specified ‘standard’ and well supported with spares and technical knowledge?

Not applicable

5.2. Is any long manufacturing lead time mechanical equipment specified and could this be replaced by more standard ‘off the shelf’ equipment?

Not applicable

Page 8


5.3. Is all mechanical equipment accessible for installation, maintenance and replacement?

Not applicable

5.4. Are the functional requirements of all mechanical equipment clearly indicated in the drawings or bills of quantities?

Not applicable

6. ELECTRICAL

6.1. Are electrical standards used in design appropriate to local practice?

Not applicable

6.2. Is electrical equipment specified ‘standard’ and well supported with spares and technical knowledge?

Not applicable

6.3. Is any long manufacturing lead time electrical equipment specified and could this be replaced by more standard ‘off the shelf’ equipment?

Not applicable

6.4. Are electrical designs appropriate for tropical installation and have resilience to lightning strikes and power fluctuations been considered?

Not applicable

7. BUILDINGS

7.1. Are building materials specified readily available?

Most are local stock items. The only exception may be pre‐cast culverts if the local manufacturer has not upgraded his factory to meet the requirements of the current design standard issued in 2006.

Page 9


7.2. Are founding conditions suited to the building foundation design?

Geotechnical investigations have confirmed acceptable founding conditions in most areas. However, where drain straightening means the new drain will deviate from the present natural irregular course in the flood plain, it will be necessary to over excavate and import suitable backfill material where the new drain invert is higher than the previous natural channel bed that largely defines the interface level between sound material and flood plain sedimentary deposits. This will include the trash trap area that will require some limited over‐excavation and backfill.

8. TRAFFIC ACCOMMODATION

8.1. Is public access disrupted? Yes there will be considerable disruption along roads where the new culverts are to be installed. This will be kept to a minimum by maximising on the use of pre‐cast concrete culvert sections and bases.

Ensure that dealing with access disruption is included in the specifications

8.2. Has access disruption to local businesses been considered?

Yes. Temporary removal of market stalls and informal shops along the drain routes will be addressed in the RAP.

Ensure inclusion in RAP

8.3. Has provision been made to ensure local people have access to their properties?

The specifications provide for temporary provision of access to people’s properties during construction.

Ensure provision of temporary access during construction is included in the specifications

8.4. Is there provision for a traffic management plan?

Provision of ensuring control of traffic e.g. through placement of adequate signs, and temporary barriers is included in the specifications.

Ensure provision of traffic management system is included in the specifications

Page 10


9. SHUTDOWNS

9.1. Will provision of water/ sanitation services be disrupted?

Yes. Shut‐downs will be necessary to allow for the installation of new pipeline sections to existing pipelines where raising or lowering is necessary. These shall be done by manually operating the sluice/gate valves that are nearest to the pipe sections concerned.

Specifications to indicate maximum periods of disruption of water supply

Specification/BoQ to include item for advertisement/ announcement of water supply disruption in local newspaper and on radio.

9.2. Is there provision for a shutdown management plan?

This will need to be agreed to with LWSC to minimise disruptions and coordinate between various work components.

Specification to include requirements for shutdown management plan.

10. RESETTLEMENT

10.1. Is sufficient survey data available to identify resettlement need?

The detailed topographical survey has picked up all walls and buildings near to drain lines.

Acquisition of a narrow strip of land on the right bank at the trash trap site will be necessary notwithstanding the fact that the boundary wall was illegally constructed within the flood plain.

10.2. Has a resettlement corridor of impact been identified and constraints arising from it indicated in the drawings

The RCOI is to be defined and some buildings and market stalls along the drain routes shall need to be temporarily removed to allow for the construction of the drains.

10.3. Where the need for resettlement has been identified have design change options been considered to eliminate or reduce resettlement needs?

Insofar as this is possible for an open gravity drainage system, yes. The selected drain routes have considered the best options where limited alignment change is practicable and permanent resettlement shall either be minimal or none.

10.4. Is sufficient space available for working without disruption to buildings and walls?

No, some areas shall require some boundary walls to be demolished to allow for the construction of the drain.

Ensure inclusion in RAP.

11. ENVIRONMENTAL

Page 11


11.1. Have construction waste materials been identified and disposal methods specified?

Major arisings will be earth, rock, crushed concrete, wall rubble and road tarmacadam. All such materials needs to be disposed of in an environmentally acceptable way

Minor arisings will be steel which can be recycled in Lusaka and timber which must be disposed of at landfill sites.

Water arising from the temporary closure of a drain section under construction will be pumped or otherwise conveyed around the section concerned.

Sewage arising from the temporary stoppering of the sewer concerned at adjacent manholes will be pumped to the next downstream manhole.

Specification to include landfill requirements. BoQ item to be provided for Council landfill disposal costs.

Specification to include for all necessary coffer‐damming, sewer stoppering and pumping.

11.2. Are any hazardous wastes expected and are safe disposal methods/ procedures specified?

Road tarmacadam to be properly disposed of to the satisfaction of ZEMA if recycling is not practicable.

Specification to indicate.

12. HEALTH AND SAFETY

12.1. As designed, do the construction methods have any intrinsic safety issues? Have these been addressed in the specification?

Deep drain sections and those where high flow velocities will occur are a safety hazard and will either be covered or properly fenced off and closed as part of the construction or as soon as possible afterwards.

Excavations are generally shallow and geotechnical investigations indicate stable trenching conditions except in some flood plain areas.

The specifications need to contain detailed requirements for health and safety regarding trenches, dust, etc.

Page 12


12.2. Are National Health and Safety regulations sufficiently rigorous when compared to international best practice or should additional HS clauses be included?

Final ESIA will cover health and safety and will propose additional specification clauses.




Gauff Ingenieure

ANNEX II-1

Work Programme LD1

ID Task Name Duration

1 Contract Package LD1 1191 days

2 Commencement date 0 days

3 Mobilisation 1 mon

4 Pre-contract Activities 0 days

5 Completion of RAP implementation 0 mons

6 Procurement Activities 847 days

7 Local Procurement 18 mons

8 Foreign Procurements (mainly for S Classs portals, if required) 6 mons

9 Preliminary Work 175 days

10 Confirm location of existing service 2.5 mons

11 Confirmation of wayleave 8.75 mons

12 Drainage Works 858 days

13 Drainage Works (14.9 km of trapezoidal drains 27 mons

14 Drainage Works (4.4 km of rectangular drains, 1.8 m covered 21 mons

15 Safety Rails (2.6 km 24.55 mons

16 Precasting of concrete members 24 mons

17 Installation of box culverts (20 nr) 12 mons

18 Walkways and Driveways 15 mons

19 Commissioning and Hand-Over 1001 days

20 Partial Commissioning and Hand-Over 1 0 mons


22 Final Commissioning and Hand-Over 0 mons

23 Defects Liability Period 1 12 mons



1/2

12/9

12/9

9/1

9/1

8/1

F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J Af 1, 2013 Half 2, 2013 Half 1, 2014 Half 2, 2014 Half 1, 2015 Half 2, 2015 Half 1, 2016 Half 2, 2016 Half 1, 2017 Half 2, 2017 Half 1, 2018 Half 2, 2

Task

Split

Milestone

Summary

Project Summary

External Tasks

External Milestone

Inactive Task

Inactive Milestone

Inactive Summary

Manual Task

Duration-only

Manual Summary Rollup

Manual Summary

Start-only

Finish-only

Progress

Deadline

LD2: Improvement of Bombay Drainage System (south

Page 1

Project: LD1Date: Tue 2/26/13




Gauff Ingenieure

ANNEX II-2

Work Programme LD2

ID Task Name Duration

1 Contract Package LD2 1367 days

2 Commencement date 0 days

3 Mobilisation 1 mon

4 Pre-contract Activities 0 days

5 Completion of RAP implementation 0 mons

6 Procurement Activities 847 days

7 Local Procurement 18 mons

8 Foreign Procurements (mainly for S Classs portals, if required) 6 mons

9 Preliminary Work 175 days

10 Confirm location of existing service 2.5 mons

11 Confirmation of wayleave 8.75 mons

12 Drainage Works 1037 days

13 Drainage Works (14.9 km of trapezoidal drains 30 mons

14 Drainage Works (4.4 km of rectangular drains, 1.8 m covered 25 mons

15 Safety Rails (2.6 km 24.55 mons

16 Precasting of concrete members 24 mons

17 Installation of box culverts (20 nr) 12 mons

18 Walkways and Driveways 15 mons

19 Commissioning and Hand-Over 937 days



22 Final Commissioning and Hand-Over 0 mons

23 Defects Liability Periods 1176 days




1/2

12/9

12/9

9/1

9/1

4/3

F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A Mf 1, 2013 Half 2, 2013 Half 1, 2014 Half 2, 2014 Half 1, 2015 Half 2, 2015 Half 1, 2016 Half 2, 2016 Half 1, 2017 Half 2, 2017 Half 1, 2018 Half 2, 2018 Half 1, 2019

Task

Split

Milestone

Summary

Project Summary

External Tasks

External Milestone

Inactive Task

Inactive Milestone

Inactive Summary

Manual Task

Duration-only

Manual Summary Rollup

Manual Summary

Start-only

Finish-only

Progress

Deadline

LD2: Improvement of Bombay Drainage System (south

Page 1

Project: LD2Date: Tue 2/26/13