34.ms for earthwork excavation

LARSEN & TOUBRO LIMITEDECC DIVISION

of 5EARTH WORK EXCAVATION

VISAKHAPATNAM LPG STORAGE CAVERN PROJECT 10th Dec 2004

METHOD STATEMENT FOR EARTHWORK EXCAVATION

Prepared & checked by (L&T) Reviewed by (L&T) Approved by (SALPG)

QA TL / AG TL PROJECT MANAGER

Document No: 033/MS/04 – 032 Rev 03 Method statements\033-AG\Earth.excavn.doc



VISAKHAPATNAM LPG STORAGE CAVERN PROJECT 10h Dec 2004

Table of contentsPage No.

1.0 Objective 03

2.0 Scope 03

3.0 Codes and Specification 03

4.0 Construction Equipments and Instruments 03

5.0 Procedure 03

6.0 Formats/Attachments 04

7.0 Safety 05

Document No: 033/MS/04 – 032 Rev 03 Method statements\033-AG/Earth.exavn.doc




1.0 Objective

Objective of this method statement is to execute the excavation works for All buildings and structures of SALPG.

2.0 Scope

The scope of this method statement is give guidelines for doing the excavation works.

3.0 Codes and Specification

IS 1200 (part 1) method of measurement IS 2720 method of test of soils SP - CIV - 202

4.0 Construction Equipment and Instruments

Earth Excavator, Tipper. 5 T Vibratory Roller & Plate compactor

5.0 Procedures

Set out footing locations taking reference from grid markers. Excavate to required depth manually or mechanically and check the formation condition by consultant or designer, if required. For mechanical excavation, excavate approximately 150 mm above required depth. Balance 150 mm by manually to avoid over excavation and for deep excavation provide shuttering & shoring. The same shall be designed to suit the site condition. Keep the excavated pit free from water, Use dewatering pumps if required. Complete excavation, trim to required level, check level & dimension, approve for PCC. Tolerances + 20 mm. After the excavation the surface shall be compacted with5 passes of a 5000 kg per meter width vibrating roller.

For excavation works in unstable areas, slopes shall be stabilized moreover. Gradient slopes shall be as per the approved working drawings. In case of earthworks in the presence of underground water, the water should be dewatered by pumps or other approved methods. All the hard elements found at excavation pit bottom such as rocks, foundation remains, etc shall be removed and the pockets that are of a softer nature than the rest of the excavation pit bottom shall be purged and replaced by materials that are comparable to rest of the soil at that level. Materials from excavation shall be put in provisional deposits and may be re-used for filling –in or evacuated to the permanent deposit if they are considered unsuitable for re-use. Existing structures are being protected while doing


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excavation near by such that soil shall not move that may result in damage to existing structures.

Hard Rock Excavation:

At all stages of excavation, precaution to be taken to preserve the rock below And beyond the lines specified for the excavation, soundest possible condition. Storage facilities for the explosives to be made as per the rules of local, state and central government authorities and statuary bodies / regulation and procedures for storage to be followed as described in technical specification for hard rock blasting.

Blasting to be carried out during the fixed hours of the day (after sunrise and before the sunset) as approved by the client in written. Notification to be given to all companies and public utility companies having service or enable them to protect their property from injury. Required holes as specified to be made by the supervisor (c/c of hole shall not exceed 2.0 m). Wooden tamping rod with a flat end shall be used to push cartridges in the hole firmly. After insertion of explosives to the required depth in the hole, the balance hole shall be stemmed, consisting of sand or stone dust. The blast area to be covered with one layer of sand bags, above the sand bags (60bags / Sqm) MS plate of minimum 6mm thick to be placed. One row of sand bags to be placed on the steel plate. Precaution to be taken to ensure the blasting circuit is adequately taped to avoid contact with MS plate. The detonation of the explosives to be done electrically.

Misfire:

01.Sufficient time shall be allowed to account for the delayed blast. 02.Inspection to be done in all the charges and determine the missed

one. 03.The explosive materials to be removed with the help of air compressor

by blowing air through that hole or it may be flooded with water.

6.0Formats / Attachments

QSF/EAR/F01





7.0 Safety

Obtain work permit before starting blasting work.

Provide proper slope as per the soil condition.

Any pit exceeds 1.2 m depth must have barrication.

Ladder to be provided for safety access to the pit exceeds 1.2 m depth.

The entire blasting site shall be covered with wire mesh or net, which can suppress the fly fragments.

The charge concentration per hole shall be restricted to 0.5 kg per hole and the cumulative charge concentration per delay in any round blast at one time shall not exceed 2.00 kg per delay.

The safe distance may be maintained up to 100m radius, we call it as danger zone.

Sufficient warning to be given through siren before blasting.


34.ms for earthwork excavation

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