Volume 30, Issue 2 (March 2007)
Simulation of Pressuremeter Shearing Mode by True Triaxial Apparatus
Pressuremeters are commonly used for determining the modulus of soil in the field. The shearing plane of the pressuremeter differs from those in the conventional laboratory strength tests; therefore the moduli obtained from these tests may be different. This paper describes the method of using the true triaxial apparatus to simulate the shearing mode of the pressuremeter. The true triaxial tests were performed by shearing the soil sample in the plane similar to that of the pressuremeter tests at the same depths on Bangkok clay.A pore water pressure probe was introduced to the true triaxial, enabling the pore water pressure at the middle of the sample to be measured. To compare the results of pressuremeter and true triaxial tests, the stress-strain relationship of the true triaxial test was used as the input in the finite element _FE_ analysis, and a predicted pressurevolume expansion curve was generated from the FE analysis. The prediction was compared directly with the results of the pressuremeter tests, indicating relatively good agreement in the pressure-volume expansion curves from elastic to plastic range.