About 50g of undisturbed sample will be needed to carry out this test. Because "free swell" is defined as the change in volume of the dry soil expressed as a percentage of its original volume, it can be calculated from the equation:
free swell = V - 10 x 100%
10
where;
V = volume of settled solids
Direct Shear Test (BS 1377: Part 7: 1990: Clause 4)
The direct shear test apparatus for performing single shear is essentially a rectangular or circular box having separated lower and upper halves. For this research, a rectangular shearbox will be used.
In the standard type of apparatus, the box is 60 mm x 60 mm. Both disturbed and undisturbed sample will be used in this test. Three different loads will be applied as the vertical load. They are 1.25 kg, 2.5 kg and 3.75 kg with 7 different samples for each load. The straight-line equation for the limiting shear stress that suggested by Coulumb in 1776 is given below:
τ = c + σn tan Ø
Where;
c = apparent cohesion (assumed to be constant)
σn = normal stress or slip surface
Ø = angle of friction (or angle of shearing resistance)
Vane shear test
The vane shear test consists of inserting a vane into the clay soil and then rotating it by applying a torque [14]. The torque is measured and for a known-size vane, is easily related to the shearing strength of the clay soil. The equation for the applied torque is given by:
T = cu πhd x d + 2π d2 x d
2 4 3
where;
T = applied torque
cu = undisturbed undrained strength
h = height of blade
d = width of blade
Hence cu = T
(1/2) πd2 [h + (1/3)d]
This research basically study on the shear strength of clay soil with certain water content. It includes of swelling analysis, shear strength analysis and water content analysis. The purpose of shear strength analysis is to ascertain the suitable water contain needed for clay soil in RECESS KUiTTHO to perform optimum shear strength.
Shear Strength of Clay Soil in Recess kuittho
At the end of the study, the highest shear strength that clay soil in RECESS KUiTTHO is able to produce can be determined according to the percentage of water content that had been applied in the range of 15% until 65%. Meanwhile, the percentage of optimum moisture content can also be identify in producing the highest shear strength clay soil for the purpose of load supporting such as building structure and so on. As conclusion, the objectives of this research will improve the original shear strength of clay soil in RECESS KUiTTHO.
