Introduction
The borrow excavation shall consists the operations such as site clearing, stripping of the overburden and stockpiling. Excavation would only be proceeded where those sites have been approved as borrow sites to be used in the construction work.
Abreviation
QAE – Quality Assurance Engineer
SE – Site Engineer
TO – Technical Officer
QAS – Quality Assurance System
ME – Materials Engineer (Contractor)
TS – Technical Specification
Resource Allocation
Man power
• 1 No Supervisor.
• Un skilled labors
• Operators
Equipments
• Track Back-hoe loaders
• Dump trucks
Quality Control Procedures
Sampling and testing
Samples of soil would be taken from the borrow location and those samples would be placed in a polythene bag providing identification tag. All required tests would be carried out in the materials testing laboratory to confirm that those materials are in which category. After testing and with the satisfying results, excavation would be preceded and those materials would be stock piled at the site.
Even the materials are properly stock piled at the site the materials in the stock pile would be tested before issuing for the construction purpose. No materials would be allowed to execute in the construction work until the required tests are completed and satisfied.
Inspection Check list
To ensure that the all activities being performed with the expected quality, an inspection check list would be filled by the person in charge for the borrow excavation in case of preconstruction, during construction. The inspection check list shall include the specific requirements, safety and environmental measures. See Inspection Check List
Dimension control
In case of the excavation of borrow materials, it is essential to have the designated limits of the borrow site to maximize the quality of the borrow materials. When the excavation is beyond the designated limit, it tends to mix with unsuitable materials.
Methodology
Clearing of the borrow site
1 The location and dimensions of the borrow pits would be identified as instructed by the Engineer.
2 All ordinary jungles, stumps and roots would be removed by a manual mean or using any other suitable equipment within the approved borrow area.
3 All removed matters would be collected to a place and then they would be disposed to a suitable disposal location or burned at the site with the judgment of the Engineer.
Stripping of the overburden
1 The overburden would be removed up to the required depth by using suitable mechanical devise and those materials would not be allowed to mix with other materials classified as suitable for filling.
2 The all unsuitable materials would be disposed to a suitable disposal location by means of tipper trucks.
See Flow Chart of Borrow Excavation
Excavation
1 Borrow excavation would be carried out using a Back-hoe loader and would be properly stock piled with well-drain facilities. The material from the borrow pits would be blasted, ripped and excavated in a manner that will ensure the effective breaking down of the material in the borrow pit before it is loaded.
2 Rippable material which tends to break into large blocks would be cross ripped. Borrow materials would be confirmed to the requirement before the application. Dump trucks would be applied for the transportation of borrow material.