Method Statement - Bored Cast-In-Place Piles

OBJECTIVE

1. To outline the instruction by which the piling works for bored cast-in-place piles are carried out.

MATERIALS

1. Concrete grade 30
2. Reinforcement as specified

PLANT, MACHINERY AND EQUIPMEN

1. Rotary auger, Tremie attached with hopper, Hydraulic ram or Jaw.

 PREPARATORY WORKS

1. Obtain approved construction drawings from the client / client’s representatives.
2. Setting out shall be carried out from reference lines and points shown in the drawings. Immediately before installation of the pile, the pile position shall be marked with suitable identifiable pins or markers. The maximum permitted deviation of the finished pile from the center point shown on the setting out drawing shall be 75mm in any direction. The permitted deviation of the finished pile from the vertical is 1 in 75.

 WORK METHODOLOGY

1. Boring through soil shall be by rotary auger only. Boring                                                through rock shall be by use of approved rock drilling equipment. Boring shall be carried out to depths instructed by the S.O Standard penetration tests shall be carried out in pile borings to the requirements of test 19 BS 1377;1975.
2. During the process of boring a pile through weak strata, drilling fluid materials bentonite shall be used to maintain the stability of the bore. The level of drilling fluid in the excavation shall be maintained so that internal fluid pressure exceeds the external ground water pressure.
3. A permanent casing will be installed up to a stable stratum (SPT value=50). Then continue boring operation to founding level. Rock tools or chiselling shall be used for boring through rock where auger can not be used.
4. If the soil below casing toe level is still found unstable then extend length of permanent casing by welding and push the casing further down to a stable stratum.
5. On completion of boring and where inspection of a dry pile bore indicates the necessity, loose, disturbed or softened soil shall be removed from the bore.
6. Each pile boring shall be inspected prior to the placing of concrete in it and cage then placed. Steel reinforcement shall be provided for the whole length of piles and shall be fixed in the form of a cage with lateral ties.
7. Cast concrete to the required level. If the bore hole is dry, concrete will be discharged through a hopper with a short guide trunk. If the bore hole is filled with water, concreting will be done through a tremie pipe with an attached hopper. The pipe shall rest on the base of the boring at the commencement of the concrete pouring and it shall at all times penetrate into the concrete which has previously been poured. The concrete mix shall be such that a continuous compacted concrete shaft is formed. For piles with permanent casing, vibrators may be used when required, poke or immersion type vibrators shall only be used from the bottom of pile upwards.
8. Drawings as specified for recording “as built” location of works shall be prepared and approved by S.O.
9. Comprehensive records of all strata penetrate or bored shall be kept together with boring samples. The record shall include the following information: -

a)      Contract section

b)      Reduced level of pile position

c)      Pile reference number

d)      Nominal diameter of the bore hole

e)      Length of the bore hole

f)       Nominal diameter of the under ream

g)      Standing ground water level

h)     Date bored

i)       Date completed

j)       Depth from working level to pile toe

k)      Depth from working level to specified cut off level

l)       Length of temporary casing used

m)    Length of permanent casing used

n)    Soil samples taken and in-situ tests carried out inclusive of the interpretation and description of soils

o)      Length and details of reinforcement cage used

p)      Concrete mix used

i)     Water cement ratio

ii)    Slumps

q)      Concrete test cube results

r)       Volume of concrete supplied to pile

s)      Time spent in overcoming obstruction, delays and other interruption to the sequence of the works

t)       Weather report

Inspection Check List - General Earthwork Excavation and Backfill

Inspection Check List - General Earthwork Excavation and Backfill

No	Items have been checked :
1.	Check of setting out the works (including existing ground level, ground condition, excavated level, sub-structures and services). Excavation drawing submitted by Contractor prior to commencement.
2.	Excavation and disposal of unsuitable material to designated dumping point.
3.	Excavation executed according to drawings and specifications.
4.	Check of ground water level.
5.	Backfill material as specified.
6.	Field compaction as specified.
7.	Soil test as specified: i) Moisture content
	ii) Particle size distribution
	iii) Organic matter content
	iv) Dry density / moisture content relationship
	v) California Bearing test
	vi) Relative Density of Cohesion less soil
8	Sheet piling
9.	Safety precaution fulfilled
10.	Slopes according to drawings and specification
11.	Compaction thickness of each backfilled layer

Inspection Check List - Structural Work (Reinforcement / Concrete)

 Inspection Check List - Structural Work (Reinforcement / Concrete)

No	Items have been checked :
1.	Formwork setting out / dimensions
2.	Formwork verticality
3.	Formwork thickness / stability / prop
4.	Fixing to structures
5.	Main bars
6.	Secondary bars
7.	Links / stirrups
8.	BRC
9.	Starter bars / lapping / anchorage
10.	Covers
11.	Levels / drops
12.	Protection
13.	Water proofing membrane
14.	Conduits / services / opening / piping
15.	Cleanliness
16.	Slump / cube mould
17.	Preparation on wet weather & curing

Inspection Check list - Piling Work

Inspection Check list - Piling Work 

No	Items have been checked :
1.	Pile point setting out
2.	Pre-augering depth recorded
3.	Pile verticality before start
4.	Pile dimension
5.	Hammer drop
6.	Final set taken
7.	Pile penetration

Method Statement - Non Suspended Slab

Method Statement For Construction Of Non Suspended Slab

STAGE 1

1. Casting the ground beam 25mm lower from original depth
2. Leveling and well-compacted sub-grade and crusher run

STAGE 2

1. Placing damp proof polythene sheet and followed by B.R.C. layer 
2. Casting the ground slab to required level as specified in the construction drawing

STAGE 3

1. Leveling the slab with gradient to fall as specified in the construction drawing
2. Applying floor hardener finisher

STAGE 4

1. Forming a groove line by diamond cutter at both end of ground beam

*The illustration and information is for guidance only. Please refer to your engineer or consultant for further advise.

Method Statement For Pile Driving

SCOPE

This procedure refers only to the installation of the piles indicated. It does not include bored piles and jacked-in piles.

TYPE OF PILE

600mm Diameter Spun Pile

Working Load = xxxT          

EQUIPMENT

The following types of Hydraulic shall be used:

600mm Diameter                    -                       9 Ton Hydraulic Hammer

PILE SET CALCULATION

For this calculation, Hiley Formula will be used to compute the estimated SET for each type of pile:

Hiley formula :

SET = Awh / fL x (W+Pe²) / (W+P) – C/2

Hammer Efficiency                                         A

Mass of Hammer                                             W

Drop of Hammer                                             h

Safety Factor                                                  f

Pile Working Load                                          L

Total Mass                                                       P

Coefficient of Restitution                               e

Temporary Compression                                 C

Summary of Sets is to be attached. Set Calculation detailed with respect to hammer, drop and estimated penetration need to be provided.

The actual SET values will be recomputed at site based on the variable parameters of actual pile length installed and the actual temporary compression recorded.

SITE PREPARATION

Piling platform will be leveled prior to piling activities

SETTING OUT

Boundary survey shall be carried upon possession of site based on the pre-computation plan available. Setting out plan shall be submitted for checking and approval.

HANDLING, PITCHING, DRIVING AND EXTENSION

All handling and lifting will be at the designed lifting points and support points.

Boundary survey shall be carried upon possession of site based on the pre-computation plan available. Setting out plan shall be submitted for checking and approval.

During pitching and driving, the vertically of the pile will be continuously monitored and plumbed to ensure the pile is centrally in line with the pile axis to receive the hammer to prevent pile whip, twist or rotation.

Each pile shall be clearly marked with red ink at 300mm intervals along its length to enable the driving blows to be recorded at every 300mm depth of pile penetration.

The pile will be extended by butt-welding the steel plates on the pile heads. On completion of welding, the slag will be chipped off and wire brushed to receive red-oxide paint.

Each pile shall be driven continuously until the specified set and / or depth has been reached. A detail record of the driving resistance over the full length of each pile should be kept.

Method Statement - Concreting Work

CONCRETING WORK

OBJECTIVE
Method on how the concreting works are carried out

MATERIALS
Ready mixed concrete

PLANT, MACHINERY AND EQUIPMENT
Tower crane / Mobile Crane, Concrete Pumps, Concreting Buckets, Vibrators, Wheelbarrows, etc. as applicable

PREPARATORY WORKS
1. Request for design mix based on the concrete grades specified on structural drawings from the Ready Mixed Concrete Supplier(s).
2. Submit the proposed design mix to client / client’s representative for approval.
3. Submit request for inspection of structural members with client / client’s representative prior to concreting works using Structural Work (Reinforcement / Concrete) Inspection Checklist and Inspection and Test Plan.
4. Carry out receiving inspection of ready mixed concrete as per Material Receiving Inspection Checklist.
5. File completed Material Receiving Inspection Checklist as per Project Filing Index.

WORK METHODOLOGY
1. Take concrete cube samples for quantity specified in the contract document.
2. Mark the location of pour for concrete received on the delivery docket and checklist as reference and identification.
3. Provide adequate equipment, machinery and manpower to carry out the concreting works.
4. Place concrete on designated locations using concrete pumps and / or crane assisted concrete buckets.
5. Start concreting from a fresh location or a predetermined construction joint and continue uninterrupted up to the next predetermined construction joint or to completion.
6. If concreting is to commence from a construction joint, roughen the joint before placing the concrete when wire mesh is not available.
7. Place concrete from the lowest point to the final concrete level in one operation in horizontal layers.
8. Compact concrete by mechanical vibrators. Ensure that concrete is worked into the corners of the structural members.
9. After the concrete has set, carry out curing works by applying curing compound.

Method Statement - Placing Formwork

PLACING FORMWORK

OBJECTIVE
The method statement for placing of formwork

MATERIALS
Steel Form, Timber, Plywood, nails, scaffolding, frame / accessories

PLANT, MACHINERY AND EQUIPMENT
Crane, Lorry and Backhoe

PREPARATORY WORKS
1. Obtain relevant approved construction drawings from client / client’s representatives.
2. Set out the locations, centre lines and levels for formwork along with reference lines.
3. Prepare necessary formwork panels to the required dimensions and sizes.
4. Coat formwork surface evenly and thinly with release agent like form oil etc.

WORK METHODOLOGY
1. Erect the formwork by providing sufficient props and struts including necessary bracing.
2. Use scaffolding and staging arrangements, where necessary.
3. Seal gaps in formwork to avoid leakage of grout.
4. Ensure checking for the required shape and dimensions as per drawings.
5. Submit Request for Inspection Form for joint inspection with client / client’s representative using Structural Work (Reinforcement / Concrete) Inspection Checklist.
6. On completion of joint inspection, request client/client’s representative to sign on the checklist and file as per Project Filing Index.

Method Statement - Excavation And Backfill

EXCAVATION AND BACKFILL

The method statement by which the excavation and backfill with suitable fill is carried out.

PLANT, MACHINERY AND EQUIPMENT

-Excavator, Dump Truck, Dozer, Compactor and Back pusher.

PREPARATORY WORKS

1. Obtain relevant approved construction drawing from client / client’s representatives.

2. Set out the location and limits of work.

3. Carry out survey to obtain original ground level, excavation level and final backfilled level.

WORK METHODOLOGY

1. Prepare access to the working area and plan for the dump truck and plant movements.

2. Excavate to the required depth as indicated on construction drawing and dispose off at dump site.

3. Transport, fill and spread suitable material and compact as required.

4. Repeat step 3 until the required level is achieved.

5. Submit Request for Inspection Form for joint inspection using General Earthworks Excavation And Backfill Inspection Check-list.

6. On completion of joint inspection, request client / client’s representative to sign on the checklist and file as per Project Filling Index

Method Statement For Construction Work

Hi..

When I Start my work as a graduate Engineer, It's hard for me to find a Standard Work Method Statement. Thus, for those who are generally fresh engineer and have no idea about method statement,

I'll try my best to update on the method statement that are normally use in construction. For those senior Engineer, professional Engineer, Please do not hesitate to leave a comment or feedback on the method statement. I can't guarantee this method is right and suit to your work condition. You'll still need to justify or get your senior views before using or comply on any materials given here. 

Oh, I'll be glad if any reader would like to share their method statement here so that we can exchange knowledge with the other reader.

Thank You.