Abstract: It is practically important to characterize the strength and deformation of various disturbed soils. The state of the practice of studying the properties of disturbed soils are laboratory testing. However, laboratory tests have very limited repetitiveness. Some conventional insitu tests, such as, cone penetration tests (CPT) and vane shear tests (VST), can only obtain the strength parameters of disturbed soils and the deformation characteristics of these soils are not available. This paper presents the disturbed strength and deformation properties of the fourth, fifth and sixth layers of typical Shanghai cohesive soils by using prebored pressuremeters. The test results indicate that, an obvious strength decrease could be found in the disturbed soils in the initial pressure, the plastic pressure, as well as the pressuremeter modulus. In addition, the disturbance on the deformation property is also significant. The pressuremeter curves have significant different before and after the soil disturbance. The limit strain after soil disturbance reduces significantly.

Key words: Pressuremeter Tests, Disturbed Soils, Stress-Strain Relations, In-Situ Tests