General requirements

023134 Limits of Pit & Trench Excavation

Pit and trench excavation shall be measured by adding 250mm to each side of the dimension giving the surface area of the volume to be excavated.

The volume of excavation for masonry works buried in ground and requiring no foundation bedding shall be measured by the net volume of buried masonry & without allowing for any working space.
023135 Rock excavation

This section covers the excavation of soft and hard rocks and boulders.

"Soft Rock" shall mean weathered material, which can be excavated using excavators, tractor drawn tines, for breaking up the material.
"Hard Rock" shall mean material requiring the use of wedges, prismatic tools, blasting to enable the excavation work to be carried out.
"Boulder" shall mean isolated volume of hard rock in ordinary soil and soft rock or above ground less than 1/2 cubic meter in volume.
Rock excavation shall be classified into soft & hard rock and boulders. The excavation for rock shall be measured in successive stages of 1500mm. Excavation shall be classified into Bulk, Pit and Trench excavation.
In the instance of the use of explosive for blasting rock, the contractor shall fully comply with the requirement of the relevant Civil code and Condition of Contract applicable to the work being considered.
Explosives shall be used in the quantities and manner recommended by the Manufacturer.
Explosives shall be stored with separate compartments provided for detonators and shall be handled exclusively by experienced and authorized personnel only.
Permanent and temporary structure damaged by explosives shall be replaced at the cost of the Contractor.
The excavated hard rock is the property of the Investor and requires the approval of the owner and payment by the Contractor for its use.

Excavated hard rock shall be stock piled in a manner enabling measurement of the volume of rock for the purpose of payment for use by the Contractor.

The methods of measurement and working space allowance for “Ordinary Soil" shall be equally applicable to excavation in rock.