METHOD STATEMENT FOR UNDERGROUND DRAINAGE PIPING

METHOD STATEMENT FOR UNDERGROUND DRAINAGE PIPING

TABLE OF CONTENTS

1. INTRODUCTION 2
2. INTERFACES & CONSTRAINT 2
   2.1 INTERFACE 2
   2.2 CONSTRAINTS 2
3. REFERENCE DOCUMENTS & DRAWINGS 3
   3.1 CONTRACT DRAWINGS 3
   3.2 SUBMITTALS, TECHNICAL REPORTS & QA\QC PROCEDURES 3
   3.3 BOJV DRAWINGS 4
4. HEALTH, SAFETY- ACCESS & EMERGENCY PROCEDURES 4
   4.1. HEALTH & SAFETY 4
   4.2. ACCESS 4
   4.3. EMERGENCY PROCEDURES 5
5. QUALITY 6
6. EQUIPMENT & TOOLS 7
7. MATERIALS 5
8. PERSONNEL 8
9. SEQUENCE OF WORKS 8
10. DESCRIPTION OF WORKS/METHODOLOGY 8
    10.1. Preparation & Pre-installation Work 8
    10.2. Co-ordination with Other Trades 8
    10.3. Installation Work 8
11. ATTACHMENTS 10
12. INTRODUCTION

1.1. The objective of this method statement is to establish the necessary guidelines for the installation of underground drainage in accordance with the contract requirements. This method Statement shall ensure that the installation of underground drainage is executed safely and in accordance with the contract requirements. This Method Statements aims to ensure that work quality assurance and quality control activities are conducted in a systematic manner, works are inspected and conformance is verified and documented.
1.2. This method statement relates to the installation of underground drainage in all areas.

2. Interfaces & Constraint

2.1. Interface
The following interfaces have been identified which affect the works:
 Waterproofing;
 Permanent reinforcement.
 Chairs and other temporary reinforcement or item used such as the formworks at construction joints.
 Concreting.

2.2. Constraints
Safety constraints:
 Before to start any work, brief all operatives about the risks involved in the work and what PPE must be used.
 When any circumstances differ from this method statement; please inform the Construction and Technical Manager immediately.
 The emergency procedure has to be discussed and understood prior to the start of the work.
 Make a safe access and egress for the operatives before to start work.
 A reasonable safe distance (to be advised by construction manager depending on type of works and situation) need to be kept for other works on the platform like lifting works.
 Installation of pipes from in between the bottom and top reinforcement of the raft.

3. REFERENCE DOCUMENTS & DRAWINGS

3.1. Contract Drawings

001-SCG-P-520-01-M07-4001/2 Draining Works – Level 01 – Zone M07
001-SCG-P-520-01-M08-4001/2 Draining Works – Level 01 – Zone M08
001-SCG-P-520-01-M10-4001/2 Draining Works – Level 01 – Zone M10
001-SCG-P-520-01-M10-6021/5/6 Draining Works – Toilets Level 01 – Zone M10
001-SCG-P-520-01-M11-4001/2 Draining Works – Level 01 – Zone M11

3.2. Submittals, Technical Reports & QA/QC Procedures

MOE-XXX-XX-XX-BO-HSP-XX-997001 Health and Safety Plan
MOE-XX-XX-XX-BO-PRO-XX-998001 Project Quality Plan
TBC ITP Piping Installation

3.3 BOJV Drawings

MOE-MA-ME-DR-BO-DWG-01-710001 till 710026 Shopping Center /Drainage Works-Underground /Level 01/M07-M08-M10-M11-L02

4. Health, safety and Emergency Procedures

4.1. Health & Safety
The Works Engineer is responsible to brief and organize the training for the workers with support and in coordination with the Safety Team, the Construction Manager and the Supervisor Concrete Works.
A toolbox needs to be held once per week with different subject and 5 minute pre task trainings before every start of the works. All trainings need to be documented. Forms are available with the safety team.

A 5 minute pre task briefing must be held by the Works Engineer with the workers every time before to start the work and the following questions need to be asked and action to be taken:
 Tell men tasks in steps.
 Who does what?
 What are the hazards and risks?
 Which measures to take?
 Which PPE to wear and does everybody have the suitable PPE.
 Does everyone understand his job?
 What went wrong yesterday what can be improved today?
 Plastic caps shall be installed on all protruding bars such as the pile starter bars.
 In addition to the mandatory site PPE, PPE shall be adapted considering the protection against product used such as glue for all workers in contact with these products.
 For installation of pipe inside of reinforcement (between bottom and top layer of the raft), special care has to be taken for evacuation and accessibility. One member of the team has always to be present outside of the reinforcement “cage” for control and contact with the surrounding environment and persons.
4.2. Access
 General access for vehicles to the working area is the existing site roads within the construction area and temporary access ramps;
 Pedestrian access area is not an issue as there is sufficient space at the working area;
 The site needs to arrange sufficient space for manoeuvring of excavators, trucks …etc.

4.3. Emergency Procedures
In any emergency, the following will be applied:
 A supervisor will establish the nature of the emergency.
 A message will be conveyed to the site office outlining the details.
 Site safety team and the doctor will be notified.
 A specific procedure is established and issued for dealing with fire on site. This forms part of the Safety Plan.
 If a medical emergency occurs, then the qualified First Aiders on site should attempt to deal with the casualty.
 All emergency duty personnel will be adequately trained to fill the emergency response role. Emergency procedures form part of the induction training so that all concerned are clear as to the action required of them in an emergency.
 Emergency Assembly Points will be established and updated as per site requirements.

5. QUALITY

 In process works shall be monitored for quality of workmanship and installation against approved construction drawings by the relevant Supervisor and Construction Manager
 All works shall be inspected for quality of workmanship and conformance to specification prior to offering for inspection
 Test piping systems in the presence of the Engineer in accordance with requirements of National Standard Plumbing Code and as specified
 Apply hydraulic leakage test for gravity drainage pipes both in its entirety and in sections after rough piping installation
 When applied to entire system, close tightly openings in the piping except highest opening and fill the system with water to point of overflow
 Sanitary drainage and vent piping: cap end or plug as required and fill with water to produce at least 3 meters head at highest point of section tested. Let stand with no loss of level for a period of four hours. After water pressure test, fill traps with water and conduct smoke test
 In testing successive sections, test at least the upper 3 meters of the next to preceding section

All works are carried out in accordance with the general QA Plan and the Inspection Test Plan.

6. EQUIPMENT & TOOLS

The following equipment & tools are required:

• Cutting saw
• Welding machine for HDPE

1. MATERIALS

 Materials shall be approved prior to procurement.
 Incoming materials shall be inspected for conformance by the Project QC. The Engineer shall be invited to inspect materials for conformance prior installation
 Relevant certificates of conformance shall be presented at the time of inspection with the Engineer.
 All materials inspections shall be recorded on the MIR (Materials Inspection Request). All major items shall be inspected for each delivery.
 Consumables and accessories need not be offered for inspection except where this is a direct requirement of the contract or specification

8. PERSONNEL

 Responsibility for the implementation of this method statement rests with the Project Director. Site supervision shall be delegated to the Construction Managers and Project Supervisors.

9. SEQUENCE OF WORKS

Two typical installation sequences are considered according to the location of installation:
o Where pipe embedded into structure concrete elements:
Pipe and required box out will be installed, secured and tested after reinforcement installation and prior concrete pouring.

o Where pipe buried into ground:
Pipe will be installed\placed into position and tested during the final earth works operation and prior blinding concrete.

Please refer to typical section & details in Attachment no. (2)

10. DESCRIPTION OF WORKS/METHODOLOGY

10.1. Preparation & Pre-installation Work:
 Works shall not proceed until an approved construction drawing or detail is issued
 Safe access to work areas shall be provided prior to commencement of works
 Materials shall be moved to the work area in a safe manner and shall not block access/ egress from the site. Suitable mechanical aids shall be used where heavy loads are to be moved or lifted into position. Such equipment shall be planned for in advance of works.

10.2. Co-ordination with Other Trades:
Co-ordinated drawings shall be developed to ensure that opening for MEP services are in accordance with approved drawing and / or site requirements.

10.3. Installation Work:
10.3.1 Preparation
 Check access is available to the area where installation is to be carried out.
 Check Materials to be used have been approved by the Engineer and are available on site.
 Check work area is clean and safe.

10.3.2 Installation:
A. General

1. Install pipes and pipe fittings as indicated in the plans and elsewhere in the specifications, in accordance with recognized industry practices which will achieve permanently leak-proof piping systems, capable of performing each indicated service without piping failure.
   Install each run with minimum joints and couplings, but with adequate and accessible unions for disassembly and maintenance/replacement of valves and equipment. Align piping accurately at connections, within 1/400mm misalignment tolerance.
2. Coordinate as necessary to interface installation of piping, fittings, and jointing with other work.
3. Locate piping runs except as otherwise indicated, vertically and horizontally (pitched to drain) and avoid diagonal run where ever possible. Orient horizontal runs parallel with walls and column lines. Locate runs as shown or described by diagrams, details and notations or, if not otherwise indicated. Run piping in shortest route which does not obstruct usable space or block access for servicing building and its equipment. Hold piping close to walls, overhead construction, columns and other structural and permanent- enclosure elements of buildings.
4. Clean exterior surfaces of installed piping system of superfluous materials and prepare for application of specified coatings (if any). During construction, properly cap all lines and equipment’s nozzles so as to prevent the entrance of sand, dirt, etc. Each system of piping to be flushed prior to testing for the purpose of removing grit, dirt, sand, etc. from the piping for as long as time as is required to thoroughly clean the system.
   B. HDPE Pipe Welding process:
    Do wear safety gloves as a protection against burning.
    A stop-watch should be available for recording the actual times for the heating and cooling.
    In the same way a table should be available from which the parameters for the pipe dimensions to be- welded prescribed by the welding prescriptions may be taken from.

 The heating element surfaces are to be clean and, above all, free from grease. Therefore they are to be cleaned with non-fraying paper and detergent (e.g. technical cleaned spirit) before every welding or if they are dirty.
The anti-adhesive coating of the heating element has to remain undamaged in the working area.

 Switch on the heating element and adjust the required welding temperature at the
Adjusting screw
The adjusted temperature is obtained when the control light is blinking.

 Screw in the reduction inserts according to the outside diameter of the pipes to be welded.
 Put the work pieces into the clamping tools, tighten the clamping nuts tightly and align the work pieces with respect to one another.

 Close the slide, thereby reading the movement pressure on the manometer,
The movement pressure is displayed exactly when the slide with the clamped-pipe passes over into its movement.
Subsequently, open slide again such that the planer fits there between.

 Swivel the planer between the pipe ends, allow handle to lock with the security micro switch and switch on.
There is the danger that the planer pulls in clothes
In case planer is switched on it will run immediately when the security micro switch has been pressed
Do not hold the planer on its front sides in any case

 Move the pipe ends towards one another by means of the valve lever and plane same with a planning pressure between 1 and 15 bar above the movement pressure.
Planning must be carried out until a revolving cutting has been formed on both sides

 Open the slide again by means of the valve lever, switch off planer motor, remove planer and put it into the neat protective box.
Remove the produced cuttings without, contacting the worked surfaces

 Close slide
 Check pipe mismatch and gap on the joining pipe ends. the mismatch on the pipe outer side
Must not exceed 0.1 x pipe wall thickness, the admissible gap must not exceed 0.5 mm.
The mismatch compensation is carried out via -further lightening or releasing of the
Clamping nuts,
In case of mismatch compensation, planing must be carried out again afterwards.

 The adjustment pressure for the pipe dimension to be welded can be gathered from the table, add the movement pressure.
Set the resulting pressure value at the pressure limiter valve and check by actuating the valve lever.

 Open slide again slightly,
 Take heating up time, maximum change-over time, cooling down time and bead height for the pipe dimension to be welded from the table.

 Move the heating element, which has been cleaned and brought to nominal temperature, by means of the handle upwards between the pipes; if necessary wait until the control lamp on the heating element flashes in regular intervals.
 Close slide smoothly to the set adjustment pressure.
When the prescribed revolving bead height has been reached, reduce pressure. For this purpose, move the valve lever to the position “pressure-less” until the desired heating up pressure has built up (heating up pressure = Approx. 10% of the adjustment pressure).
 The heating up time starts now. Press the stop watch and compare the actual time with the nominal time taken from the table.
 After expiration of the heating up time, open the slide, remove the heating elements as quickly as possible, put it into the heat protective box and close the slide smoothly.
The maximum time frame for this process is predetermined by the value for the change over time taken from the table.
 When the welding pressure has been built up, press the stop-watch and keep the control lever for approximately 10s on the position “pressure” so that the hydraulic accumulator can be filled, during the cooling down period re-adjust pressure, if necessary (the pressure for cooling down is the same as the set adjustment pressure).

 After expiration of the cooling down period release pressure, remove the welded parts and open the slide.

11. ATTACHMENTS

Attachment 1: Risk Assessment
Attachment 2: Typical Detail for Drainage Pipe in Foundation.