Earthwork specification part 2

2. Excavations

2.1. Excavation Method Statement
The Contractor shall prepare a method statement of his proposal for earthworks operation for each particular part of the Works to be constructed at any one time, detailing the location, programme of excavation, temporary supports and the placing and handling of the spoil.
The Contractor shall submit of the Engineer’s approval his proposed method statement at least twenty eight days before his intended date to commence earthworks on each particular part of the Works.


2.2. Trial holes
The Contractor shall excavate any trial holes he may require to determine the position of underground services, sub-soil drains or for any other reason. The Contractor shall arrange for the refilling and reinstatement of trial holes to be carried out immediately the required information is obtained. The reinstatement of the surfaces of trial holes shall be carried out to the approval of the Engineer.

2.3. Extent of Excavations
Earthworks shall comply with BS 6031.
The extent of excavations shall be the minimum necessary or practicable in the opinion of the Engineer for the construction of the Works.
The construction of open trenches shall, at any one time, be limited to lengths previously approved by the Engineer. Work on each approved length shall be completed to the satisfaction of the Engineer before work on any new length is commenced.
Trench widths shall be as shown on the drawings.
No excavations with battered sides will be permitted in public highways, private gardens or within 3 meters of any building or other structure.


2.4. Stripping of topsoil
Topsoil shall be stripped from the whole or part of the Site to a depth of 250 millimeters and set aside for re-use as a separate operation prior to any further excavation, which may be required.
Topsoil shall include any surface material capable of supporting vegetation and suitable for use in soiling areas to be grassed or cultivated.
The Contractor shall not dispose of surplus topsoil without the permission of the Engineer.

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Earthwork specification part 1

1.General

1.1 Notice of Commencement
The Contractor shall give at least seven days written notice of his intention to commence earthworks on any part of the site ans shall furnish the Engineer with all ground levels and other particulars he may require for the purpose of carrying out measurements.
Earthworks shall not be commenced until written approval has been received by the Contractor from the Engineer.

1.2. Soil Investigation Reports
The Employer has carried out soil investigations in each town. Soil investigation reports are available for inspection during the Bidding period in the offices of the Employer. The Contractor shall take all such additional steps that he considers necessary to familiarise himself with the surface and subsurface conditions at the site.
Soil investigation data is furnished for information only and it shall be expressly understood the Employer will not be held responsible for any interpretations or conclutions drawn therefrom by the Contractor. If during construction the soil conditions prove to deviate from those set out in the soil investigation data so that an effect may or will be experienced on the work, the Contractor shall immediately inform the Engineer.

1.3. Earthworks to lines and levels
The whole of the earthworks for the Works shall be carried out to the required dimension and levels.
For the purpose of the Specification, the term "ground level" shall refer to the ground surface before the start of earthwork operation, but after the operations of site clearance. The expression “formation level” where used in the Specification shall mean the excavated foundation level of the structure concerned including the level at the top of blinding concrete.

1.4. Borrow area
It is the Contractor’s responsibility to locate the borrow areas for all kind of materials and obtaining, transporting and placing them when needed for the execution of the Works. The Contractor shall obtain the approval of the Engineer for the areas as well as for the materials he proposes to use.
Fill material for incorporation in the Works shall be obtained from approved borrow areas after the completion of any tests to confirm the suitability of the material.
On completion of excavation, the Contractor shall trim, grade and leave the borrow area in a tidy condition and shall carry out any further earthworks necessary to prevent accumulation of water in the area.

1.5. Disposal of surplus excavated material
The Contractor shall be responsible for negotiating and securing suitable areas for disposal of surplus excavated materials and shall pay any fees or other payments associated with such disposal.
In connection with the disposal of excess spoils, the Contractor shall be responsible for the following during the Contract period:
a)Upgrading the strength and the quality of the existing access road(s) and maintaining the same in good order and final reinstatement.
b)Keeping vehicles clean when leaving the tipping area(s) and to ensure they do not contaminate public roads.

1.6. Samples and testing
Materials proposed for use during construction shall be tested on site in accordance with the procedures as prescribed in BS 1377 to determine its characteristics and suitability. The Contractor shall perform the following material tests and obtain the Engineer’s approval prior to the use of materials:
a)Determination of field compaction of excavated or imported fill, and determination of optimum dry density.
b)Grading tests for granular and other fill.
The Contractor shall submit to the Engineer for approval samples of each types of filling to be used in the works.

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