Method Statement for Excavation

METHOD STATEMENT CONSTRUCTION OF COMMERCIAL AND SPRINKLE TANK Work Activities Excavation Work Pre-start checks: checks:

The pre-start checks must cover prior to commence the excavation works:1

Avail Availabi abilit lity y of plan plantt and and equip equipmen mentt to be be used used - 2 nos of PC 200 Excavators - 2 nos of dumpers truck

2

Gro Ground Con Conditio ition ns - The information for client, The excavation area is backfilled and no contaminated. - No overhaed and undergound services at the excavation area. - Pile group at excavation area.

Planning and co-ordination

1

Planning Planning and and co-ordinat co-ordination ion between between those those involves involves in the excavtio excavtion n activities activities is essential essential to ensure ensure the safety of all members.

2. Site plans plans and drawin drawing g is refer, the depth depth of excavati excavation on is less than 6m.The 6m.The dimens dimension ion of the excavat excavation ion at the top is planned. This information need to pass to site foreman and machine operator. Figure 1 shown the planned excavation area.

3. Planning Planning the the excavation excavation work work before before work starts starts to ensure it can be carried carried out out safely. safely. Planning Planning involves as below:a

Exca Excava vati tion on Meth Method od - Ope Open n Cut Cut

b

Stati Staticc and dynami dynamicc loads loads near near the the exca excavat vation ion area. area.

c

Safe afe work work met metho hod d stat statem emen ents ts

e f

Proced Procedure uress to to deal deal with with emerge emergenci ncies. es. Dewatering System

Functional Flowchart  A c tivit y requir ing the move ment of s oi l or ground or the ins ertion of obj ects i nt o the ground

Do es t he ac tivit y involve any of the following ?

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

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Y es

S pec if ic manufac turer i ns truc ti ons or operati ona l gu ides of pl ant used (if appli cable ) is to be fol lowed as we ll as any s ign age lo c at ed i n the area

dig gi ng or mov ement of a k now n material stockpile , or  diggi ng of rais ed ga rden be ds w i th a k now n absence of underground services , or  diggi ng or cl eari ng of mat eria l / soi l bu ild up wit hi n culv erts , drains or simil ar loc at ions wi th a known absence of underground services . No

The dept h of  the exca vati on , diggi ng or i ns erti on of objec t i s <150 mm

Y es

S pec if ic manufac turer i ns truc ti ons or operati ona l gu ides of pl ant used (if appli cable ), s ignage , etc to be foll owed as wel l as any ge neral requir ements of this Co rpo rate S tan dard

No

Compl et e an Excavation & Digging Contr ol Guide  as part of pre -wo rk planning

Undert ak e an und ergroun d servi ces inv es ti gati on as per the Cont rol Gu ide req ui rements

Ident ify collap se and entry c ontrol s as r el ev ant to t he excavati on an d ac ti vi ty req ui red

Ident ify ad di tional wo rk s pec ifi c c ontr ol s rele van t t o the excavati on an d ac ti vi ty req ui red

Figure 2 : Planning Flowchart for Excavation

Imple ment c ontrol me as ures as ident ifi ed wi thin the Co nt rol Guide

3.1 Mechanical Excavation - Open cut a The area of excavated will be clearly marked on the ground serface using cements or sand

b

The machine operators was informed the dimension of the excavation at the top and the final depth of the excavation.

c

The material from the exacavtion will be loaded into the dump truck and tipped away from the working area so it does not apply a surcharge to the side of the excavation.

d

The trained supervisor to assit in the safe operation of the plant and to observe the area being excavated and to ensure there are no hit or damp to the piling for the foundation.

e

The 300mm high earth berm at the top of the slope to avoid surface run off to the excavated area after heavy rain.

f

As the excavation increases in depth the side of slope should be battered and cover with canvas to prevent collapse.

g

Care needs to be taken to avoid over excavation. Frequent levelling is necessary to check the depth of cut. Workers entering the excavated area to trim of the excavation is often required.

h

Safety supervisor and the groundwork supervisor to check the safety of the excavation. The stability on the surface have to checked when plants adjacent to an excavation area. Cut Slope cover with plastic sheet

300mm earth berm

1 1

Timber Frame Barricade ( Horizontal & Vertical )

Cut Slope cover with plastic sheet

1000mm working space

300mm earth berm

Pile cap excavation should allow approximately 1m ( Surrounding) working space

Timber Frame Barricade ( Horizontal & Vertical )

Figure 3 : Mechanical Excavation - Open Cut ( Benching & Battering )

3.2 Static and dynamic loads near the excavation area. a The stability on the surface have to checked when plants and machineries adjacent to an excavation area.

b

Precaution on the heavy load such as large equipment, heavy materials or large spoil pile can be too heavy for the sol support, resulting in a cave-in. The large spoil pile may hide the tension crack that would otherwise signal that a sliding soil failure occur.

3.3 Safe work method statements a All workers should wear the proper Personal Protective Equipment (P.P.E. ) such as safety boots whilst working, safety helmet, high visibility during night work.

b

All workers should attended a special Site Induction/ Tool Box Talk and knowledge of work safe practice before access to the work area.

c

Access/ egress for the workers entering an excavated area usually be a ladder or scaffolding stairway The scaffolding stairway constructed and extend 1 meter above top of the excavation.

d

All excavations will be a rigid barricade ( Timber frame ) and putting signage to protect the workers from the hazard during the work hours and off hours.

e

The slope have to inspected daily, it is important to watch for unsafe situations especially after heavy rain.

3.4 Procedures to deal with emergencies.

FILL UP & SUBMIT INCIDENT/ACCIDENT NOTIFICATION FORM

ACCIDENT OCCURRED (Witness / Supervisor Incharge To Inform)

KC CONTRACT Person In Charge MR.C.W LAM - H/P 012-7848832 OPERATION MR.CH'NG KHENG HOCK H/P 016-405 4001

NAB's SR PROJECT MANAGER MR.WONG SEE POH H/P: 012-474 2878 SAFETY OFFICER NAVIN TROY - H/P 016-735 4407

LOGISTIC CORDINATOR MR.LOW CHIEW KONG H/P : 012-432 8385

ACCIDENT CLASSIFICATION

MINOR (First Aid)

MAJOR (Lost Time Injury / Dangerous Occurrence)

Send Victim To Clinic / Hospital

FATALITY / SERIOUS BODILY INJURY

FIRE

UTILITIES AFFECTED

Hospital Sultanah Aminah Tel : 07 - 223 1666 / 999 KLINIK KESIHATAN TMN U TEL: 07-521 6800

Bomba Tmn U Tel : 07- 5203129 Emergency : 994

Tenaga Nasional

Send Victim To Hospital Send Body / Victim To Hospital For Post Mortem

Send Victim To Clinic  / Hospital (if any)

SET UP INVESTIGATION TEAM COMPRISING OF a) Project Director  b) SR.Project Manager  c) Construction Manager  d) Consultants e) Safety Officer 

To Review & Investigate The Accident and Identify The Cause(s) Of The Accident & Corrective Action(s) To Be Taken

REPORT WILL BE DISTRIBUTED TO a) Managing Director  b) Related Government Bodies c) Project Director / Manager  d) Head Of Department / Sub Contractor Concerned

Figure 4 : Emergencies Plan

     R      O      J      A      M

Telekom Malaysia (Tel : 100)

Syarikat Air Johor  (Tel : 072224222)

     R      O      N      I      M

3.5 Dewatering System

a

During construction, the water may accumulate from a number of sources such as high ground water table seeping into the excavation area and surface run off after heavy rain.

b

The well point or sump is constructed and the submersible pump is located to the pump sump and well piont pipes are connected by piping or hose to the adjacent drainage.

Figure 5 : Dewatering System - Pump Sump

Tanks Construction

1

The Commercial & Sprinkle Tanks is contruct according to C & S Construction Drawing No : BP 1226/17/WT/1-2 and BP 1226/17/WT/2.

2

The R.C. Works Method Statement is refer to our Letter Ref : NAB/SCTEX/KC/S6/L05 dated on 15 March 2013.

3

The R.C. Works Method Statement is refer to our Letter Ref : NAB/SCTEX/KC/S6/L05 dated on

1

Waterproofing of the Tanks Prevent water leakage on the construction joint, the 200mm wide supercast PVC waterstop is installed.

2

The waterstop is located and fixed at centre of the all round of the tanks wall while the concrete is being placed. The waterstop will prevent loss of the water from within the tnak and will prevent ingress of the groundwater whenthe tank is drained down.

Figure 6 : 200mm wide Supercast PVC Waterstop.

3

Concrete must be fully compacted or vibrated around the waterstops to ensure that no voids or porous areas remain.

4

300mm high of Concrete Wall Kicker must be construct in order the waterstops are securely held in their correct position.

200mm wide Supercast Waterstops

300mm

Figure 7 : 300mm high concrete kicker and waterstops

5

After the construction of the tanks was completed, apply 3 coats of the Shell Flintkote 3 Bituminous Waterproofing System to passive surface of tanks wall.

6

The Waterproofing System Method Statement is refer to our Letter Ref : NAB/SCTEX/KC/S6/L23 dated on 19 April 2013.

7

Cover with the plastic sheets immediately when the waterproofing system completed. This is to protect damaged to the waterproofing system.

8

Cementitious Waterproofing system is apply to internal wall prior to construct of the top concrete slab. Protection of internal waterproofing by cover a layer of plastic sheet.

9

Water Ponding Test was carry on to ensure is watertight. If any leaking after apply waterproofing then remedial work is necessary such as P.U Grouting.

1

Backfilling Works After the construction of the pilecap was completed, backfilling to fill the gap of working space by using River Sand.

2

Backfill the excavation after placement of the permanent structure such as Reinforced Concrete Tank and the 3 days cube results reach the required strength.

3

Backfill area free from stone large enough to interface with compactionand construction debris such as wood and other extraneous materials.

4

The backfill material was haul from the stock pile area by using dumper trucks.

5

Compact each layer ( 600mm per layer ) to meet the density requirements by the 1 ton roller compactor.

6

Avoid wedging sction of backfill against structures, the precaution must be taken such as place backfilling uniformly around the structures.