7. Thin wall tube sampler ∅ 3” and 2 1/4" , 0.5 m. long , for undisturbed sample in soft clay and stiff
clay first layer, respectively.
8. Drag bit ∅ 4"
9. HW casing 1.5, 1.0 m. long.
10. HW casing shoe.
11. HW casing plug.
12. Circulation tank
13. Glass jar bottles
14. etc. such as container box, label, plastic tape, wax
2.1.2 Soil Boring Procedure
The boreholes shall be carried out by skid mounted rotary type drilling rigs with hydraulic feed head
and adjustable speed. The boring shall be advanced initially by power auger for the first few meters and then
following with wash boring or rotary drilling method till the end of boring. The steel casing and bentonite slurry
shall be used for stabilizing the hole in soft clay and sandy material, respectively.
Undisturbed samples shall be taken in the soft to medium stiff clay using statically pushed thin
wall tube sampler ∅ 2 ¼ - 3 inches in diameter at the depth every 1.5 m intervals.
The disturbed samples shall be collected in the stiff clay and sandy soil using standard split
spoon sampler during the performance of the standard penetration test at the depth every 1.5 m intervals
until the end of the borehole.
The undisturbed and disturbed soil samplings shall be performed in accordance with ASTM D
1587 and ASTM 1586, respectively.
In a standard penetration test, a 2 inches O.D. split barrel sampler shall be driven into the soil stratum
with a 140 lbs safety hammer falling through a distance of 30 inches successively until a total penetration of 18
inches shall be achieved. The number of blows in the last 12 inches penetration shall be counted as the
standard penetration resistance SPT N VALUE.
Pocket penetrometer shall be used to find undrained shear strength on all cohesive soil samples in the
field. The ground water level shall be also measured one day after the completion of boring operation.
Undisturbed samples in thin wall tube shall be sealed with wax. Disturbed Samples shall be
collected in glass jar bottles and sealed with plastic cap & tape.
All samples shall be transported to laboratory later.