基于自钻式旁压试验的黏性土孔压变化研究

土孔隙水压力的准确测量有助于清楚地认识加压过程中孔隙水压力的变化规律，对工程实践具有重要的指导意义。剑桥自钻式旁压仪是英国Cambridge Insitu公司生产的一种先进的原位测试仪器，能够在加压过程中准确测量土的孔隙水压力。通过对两类土性相差较大黏性土的自钻式旁压试验及孔隙水压力的数据分析，认为：在加荷过程中，软黏性土的有效应力呈单调增大趋势，产生的孔隙水压力先增大，后减小；硬黏性土中产生的孔隙水压力变化幅度明显小于软黏性土，但其孔隙水压力的绝对值要比后者大得多。上述分析结果表明土的强度和刚度是影响孔隙水压力变化的重要因素。

Study on Changes in Pore-water Pressure of Clays Based on Self-boring Pressuremeter Test

During the loading, a high precision measurement of pore water pressure is helpful to understand explicitly the rule of changes of pore water pressure in clays, and plays an important role in instructing the engineering practices. The Cambridge self-boring expansion pressuremeter manufactured by Cambridge Insitu Companly in British is an advanced site investigation device. By means of tests, the instrument provides accurate information about pore water pressures during pressing. Two different types of clays are tested with the self-boring pressuremeter, and in situ data about pore water pressure are analyzed. The test results show that during the loading phase, an effective stress in clays increases monotonically, while pore water pressure generated in creases at the starting, and then decreases. Beside that, the amplitude of pore water pressure accumulated in a stiff clay is lower than at in a soft clay; however, the absolute value of pore water pressure of former is further higher than that of the latter, which indicates that the strength and stiffness of clays are important influence factors to the changes of pore water pressure.