EARTH WORK

2. EARTH WORK

2.1 Scope of Work
Earth work consists of excavation, back filling and disposal of surplus Material. Work of this section includes all measures and materials required to
complete the design supply, support, use, construction, removal of earth work.
2.2 Excavation
The ground shall be excavated to the lengths, widths and exact depths required for the construction of the works. The contractor shall examine any unsuitable or weak ground material, standards of which are given below and shall report the situation in writing to the Engineer before executing concrete or any other Works.
if the surface of a subgrade is found to be unstable or to include any type of refuse subject to removal in the opinion of the Engineer, the contractor shall excavate and remove such unsuitable Material to the width and depth required by the Engineer. Any excavation to a level lower than that indicated on the drawings shall be compensated for filling with concrete mix (1:4:8)
or with other material as directed by the Engineer at the contractor's expense.
Due weather to negligence or error on the part of the contractor or at the request of the Engineer owing to an unstable sub grade, the contract price shall be deemed to cover the whole cost of all excavation, inclusive of replacement with suitable Material, necessary in what so ever typo of earth or ground conditions encountered, e.g. earth With boulders, hard pan , rock, old concrete foundation, roadways, paved areas, etc.
All excavation works shall be kept dry and clean in order that work may not be affected or interfered with by water entering the excavation. The contractor shall pump out all water which may occur or be brought into the excavation employing such equipment as engines, pumps pipe work, chutes and other necessary devices to keep the water level below the bottom of the permanent works during the period required by the Engineer, Raised water shall be conveyed away in such manner as not to cause any nuisance or injury to the occupants of adjacent properties or sites. If pumping is required f it shall be carried out continuously and my not be stopped without the permission of the Engineer .
Excavated material, approved by the Engineer for re-use for filling shall be selected, loaded and hauled to the specified location for temporary stockpiling. Excavation materials containing brushy roots or other vegetable materials shall be classified as unsuitable for fill.
The sides of excavation shall be supported as necessary to Maintain a vertical face and to prevent fall or slip of any nature at any - time during the duration of excavation and back filling works. The contractor shall be responsible for the design, supply, fixing and removal of the shoring, sheet piling or any works required to support the side of the excavation.
It is also the contractors responsibility to protect existing structures and utilities from damage or interruption of services due to excavation work .

2.3 Disposal of Surplus
The contractor shall be responsible for all surplus soil of excavated material not suitable for re-use . The Engineer my require the contractor to transport such surplus to a disposal area and /or my instruct the contractor to dispose of the surplus to a disposal area to be procured by the contractor himself - This shall all be carried out by the contractor at no extra expense to the employer.

2. 4 Filling
2. 4. 1 Backfilling
Excavation shall not be backfilled until such structures and properties as drainage, insulation pipes, construction details, and water tightness have been inspected, tested and approved by the Engineer .
All available precaution shall be taken during back filling to ensure that the pipes, insulation and construction details are not damaged. All backfill material shall be approved and free from vegetable or organic material, mud, refuse, boulders, rock , stones of over 15 cm and other materials which, in the opinion of the Engineer, are unsuitable.
Filling shall be carried out in such away and to such a generous depth as to ensure that the final surfaces after settlement and compaction conform to the levels indicated in the Drawings and specifications .
2. 4. 2 Compaction

Compaction of fill (under ground pipes and those buildings or structures where concrete fill is not c quir required).
All soil fill material used shall be thoroughly compacted by mechanical means until the specified degree of compaction is obtained. The filling Material shall be approved by the Engineer and placed in even layers of a depth not greater than 30cm . A power driven roller of least 10 tons shall make at least 10 trips for each layer unless otherwise specified.
Every effort shall be made to compact the fill material at its optimum moisture content for compaction. In any case, the dry density of compacted soil shall not be less than 95% of the value obtained in a standard laboratory test. When spade will not permit the use of rollers, other types of approved equipment shall be used to achieve the same degree of degree of compaction specified. Filling and compacting around pipes, cables and conduits shall be done by hand using selected Materials to depth of the least 50cm above such pipes, cables and conduit .

2. 5 Hard Core
Where indicated on the drawings or directed by the Engineer, broken brick, hard stone or gravel free from vegetable matter and lump of clay shall be laid on the compacted subgrade to a thickness of 80mm.
2.6 Protection Against Termites
Selected appropriate anti-termite method approved by the Engineer shall be executed in accordance with the local procedures and Manufacturers instruction on the excavation bottom surface and the materials used for filling or backfilling and to the sores.