Analysis and experimental study on thixotropy of Tianjin soft clay
HUO Haifeng1，QI Lin1，LEI Huayang2，YU Ge3
(1. School of Airport Engineering，Civil Aviation University of China，Tianjin 300300，China；2. School of Civil
Engineering，Tianjin University，Tianjin 300072，China；3. School of Sino-European Aviation Engineering，
Civil Aviation University of China，Tianjin 300300，China)
Abstract：Vane shear tests on Tianjin soft clay were performed to obtain the strength of disturbed clay. The test results indicated that the strength change exhibited the positive thixotropy. The strength had a gain of 3.0 kPa after 100 minutes，then increased 1.8 kPa after 1 year. It would take 4 years at least for the disturbed clay to recover completely. The electrostatic force abiding the minimum-energy principle， the existence of the iron oxide (a significant component of cementing material) in Tianjin clay，the non-reversible grain cracking and the good drainage condition were found to promote the strength increasing. The direct shear tests showed that，as the normal pressure rised，the strength increment increased while the increment of thixotropic ratio decreased. The water content had little influence on thixotropic ratio.