上覆压力存在条件下防渗墙刺入土体变形的模型试验研究

Experimental study on soil deformation due to penetration of impervious wall considering overburden pressure

采用在三轴压力室上改造的物理模型实验室,针对防渗墙墙端与土相互作用的特点,进行了不同上覆压力存在条件下模型墙与土的刺入物理模型试验研究。研究结果表明:不同上覆压力下,墙端阻力随刺入变形呈现较大的差别;相同刺入量情况下,墙端阻力随上覆压力的增大而增加;在一定的上覆压力下,墙端阻力随刺入变形的增加而增大,但存在一个极限值;墙端阻力对墙周围土体影响范围较小,墙端阻力及刺入变形增加土体竖向变形,墙端土体主要表现为竖向压缩变形,墙端平面以上的土体有斜向下运动的趋势。在此基础上提出了描述墙端阻力-刺入变形曲线的数学表达式。

A new experimental apparatus is professionally developed to investigate the behaviors of the interface between diaphragm wall end and soil considering overburden pressure.The results indicate that:(1) the wall end resistance with penetration-induced deformation appears large difference under different overburden pressures;(2) the wall end resistance increases with the increasing overburden pressure under the same penetration-induced soil deformation;(3) the wall end resistance increases with the increasing penetration-induced soil deformation under the certain overburden pressure,but it has a limit value;(4) the wall end resistance has a small influence on the surrounding soil.The wall end resistance and the penetration-induced soil deformation increase the vertical deformation of soil.The soil below the wall end appears vertical compressive deformation,and the soil above the level of wall end has downward movement trend.On the basis of the tests,mathematical expressions for the wall end resistance and the penetration-induced soil deformation considering overburden pressure are proposed.