湿喷桩施工中饱和粉土的触变性研究

Thixotropy of saturated silty soils due to construction of DCM columns

针对某高速公路软基处理中出现的湿喷桩下沉现象,通过埋设孔隙水压力传感器和土压力传感器,比较湿喷桩施工桩周土的水平向土压力和超孔隙水压力的大小关系,提出湿喷桩下沉的判别方法。根据现场静力触探试验、取土样和室内土力学试验结果,分析湿喷桩施工扰动下饱和粉土的触变性,粉土强度随时间延长而增加。

Sinking of DCM columns at their tops occurs in some highways. In order to explain the reason of the sinking of DCM columns, pore water pressure cells and earth pressure cells are installed in the soils among DCM columns at different depths. A method to predict the sinking of columns is presented according to the difference between the earth pressure and the excess pore water pressure. The thixotropy of saturated silty soils due to the construction of DCM columns is studied using the results of static cone penetration tests and in-situ and laboratory results of soil mechanics. The strength of saturated silty soils increases with time aiter the construction of DCM columns.