SOIL INVESTIGATION

 

 Soil investigation

1.1 Scope

This work shall consist of obtaining soil samples and performing in-situ field tests at various depths below ground level and laboratory testing on selected soil samples.

1.2 EQUIPMENTS

·         Rotary drilling rigs.

·         Tungsten drag bit/ core bit.

·         Casing pipe of 100m for bore hole.

·         Water tank.

·         Pulley

·         Pump

·         Hose

 

1.3  Methodology.

• Proposed bore hole location shall be marked based on proposed co-ordinates from the approved drawing.
• The marked locations shall be verified and adjusted accordingly to avoid any site obstructions such as existing drains, sumps and traffic lights, etc.
• Boring machine shall be set properly so as no obstructions shall commence during drilling and sampling.
• During of bore hole shall be carried out using drilling rigs with water as the flushing medium.
• Borehole shall be washed out completely before collecting the samples.
• Nominal diameter of 100mm pipe shall be used for bore hole casing to support unstable borehole wall from collapsing.
• SPT N- values and type of soil shall be noted in a field observation for uniform thickness as specified by the engineer.
• Undisturbed samples shall be performed at every change of stratum or at specified depth by the engineer.
• Disturbed samples shall be placed in durable plastic containers of least 50cm3 and labeled immediately in all respects for each sampling.
• Undisturbed samples shall be trimmed to about 25mm at the bottom and sealed with molten paraffin wax at both ends to make them air-tight.
• Generally, soil investigation work will be carried out up to 1.5 times the least lateral dimension of the foundation.