中文摘要：

为获得扰动黏土静置后强度变化规律,针对天津滨海软黏土开展十字板剪切试验研究。研究结果表明,软黏土强度变化呈正触变性。静置100 min后强度增长3.0 k Pa,继续静置1 a增长1.8 k Pa,剪切强度完全恢复至少需要4 a时间。影响土体触变性的因素中：静电力作用遵循能量最低原理;氧化铁胶体是天津黏土胶体的重要构成部分;颗粒剥落不可逆;良好的排水条件可促进强度的增长。通过直剪试验发现,随着法向压力增加,强度增量不断增大,触变比增量不断减小;而含水率对触变比变化影响较小。

英文摘要：

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 k Pa after 100 minutes,then increased 1.8 k Pa 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.