异常温度作用对粉质黏土抗剪性能的影响

异常气候对粉质黏土抗剪性能有重要影响,通过对重庆市典型粉质黏土进行异常温度下力学性能研究,分析了异常温度作用下土体抗剪性能的变化规律。结果表明,高温及其持续作用可增强土体的抗剪强度,黏聚力对抗剪性能的影响大于内摩擦角,当高温作用达到一定时间后,内摩擦角则呈现出弱化抗剪性能的作用;黏聚力在各温度作用下,随作用时间的增加而增大,当作用时间超过48 h后,在10～50 ℃温度范围内,温度的变化对土体黏聚力的影响不显著,超过50 ℃以后,黏聚力随温度的增加而增大,当作用时间超过7 d后黏聚力则增加明显;内摩擦角随温度作用时间的增加而增大,当作用时间超过12 h后,在10～40 ℃范围内,温度影响不显著,超过40 ℃后,内摩擦角随温度增加有小幅减小。

Shear Properties Changes of Silty Clay due to Unusual Temperature Action

Unusual climate has an important effect on the shear performance of silty clay. Studies for unusual temperature action on silty clay in Chongqing area were carried out, and the variations of shear performance of soil acted by unusual temperature were analyzed. The results show that high temperature and its duration can enhance the shear strength of silty clay. The cohesion has greater effect on shear strength than the internal friction angle, and the internal friction angle presents a weakening the effects of shear strength after the time of temperature action reaches a certain limit. In various environment temperature, the cohesion increases with increasing of temperature action time. When the time persist beyond 48 h, the temperature can seldom influence the cohesive strength of silty clay in the 10～50 ℃, and after 50 ℃ or more the cohesion increases with the increase of temperature. When the action time of temperature last longer than 7 days, the cohesion increases markedly. The internal friction angle increases with increasing of temperature action time. When time persists beyond 12 h, the temperature can seldom influence the internal friction angle of silty clay in the 10～40 ℃, and after 40 ℃ or more the internal friction angle of silty clay slightly reduced with increasing of temperature action time.