Abstract: Both the shear strength indices and the stressstrain characteristic of the expansive soil and rock materials in Chengdu Wangjiangjinyuan are studied by the in-situ pressure-shear tests and horizontal shear test. The test results show that, under the same normal stress, the soil samples from deeper depths which has less influence by the precipitation has a higher shear strength and much larger shear strength indices than samples from the shallower depth. The shear strength values have strong correlations with the water content of the soil samples. It is concluded that the importance of control the water content during the construction.

Key words: Expansive Soils, Shear Strength, In-situ Shear Test, Water Content