深部黏土高压K_0固结试验及微观结构研究

High Pressure K_0 Consolidation Test of Deep Clay and Study on Microstructure

静止土压力系数K_0值是岩土工程中十分重要的参数,是确定水平场地中土体应力状态的基础。在高固结应力下,由于土的流变性使土发生次固结,K_0值亦发生变化。采用深部黏土重塑土样,利用SKA-1型固结仪,分别进行了固结应力为6、8、10、12、14、16 MPa,固结时间为1、3、7、14、28 d条件下的K_0固结正交试验,进而分析了固结应力和固结时间对K_0值的影响规律。同时,对不同固结时间的土样进行了扫描电镜观测,通过微观结构研究,结果表明随着固结时间的增加,试验的面孔隙度逐渐降低,定向度有逐渐增加的趋势。

The coefficient of soil pressure at-rest K0is a very important parameter in geotechnical engineering,which is the base of determining the stress state of soil underground.Due to the rheology of the soil,the soil has been secondary consolidation under high-pressure,the value of K0also changed.Deep remoulded clay sample was used by the SKA-1consolidation apparatus,then made orthogonal experiments under different consolidation stress(6、8、10、12、14、16MPa)and under different consolidation time(1、3、7、14、28d)of deep clay,then analyzed the value of K0under the influence of consolidation stress and consolidation time.The soil samples of different consolidation time were observed by scanning electron microscope,on the study of microstructure,it showed that with the increase of the time of consolidation,the surface porosity was gradually decreased and degree of orientation was gradually increasing.