RT模式下地震非极限主动土压力的拟动力分析

Pseudo-dynamic analysis of seismic non-limit active earth pressure in RT mode

为考虑挡墙位移效应对地震土压力的影响,依据前人试验研究的结论,将摩擦角表示为与挡墙位移量和位置高度相关的函数,然后基于拟动力法和水平层分析法,推导得出RT位移模式下的地震非极限主动土压力和合力作用点的计算表达式。计算模型可描述摩擦角沿着墙高逐渐发展的不同非极限位移状态工况,并建立了挡墙位移、地震动荷载和土压力之间的相互联系。参数分析讨论了振动时间、挡土墙位移状态、地震加速度参数和土体摩擦角对地震主动土压力分布、合力大小以及合力作用点高度的影响。相比于传统的极限状态地震土压力理论,所提方法更合理地描述了地震土压力随挡墙位移的发展过程,对发展非极限土压力理论和改进边坡工程中的抗震计算方法具有一定的参考意义。

In order to consider the influence of the displacement effect of the retaining wall on the seismic earth pressure,according to the conclusions of previous experimental research,the friction angle is expressed as a function related to the displacement and the position height of retaining wall.Then based on the pseudo-dynamic method and the horizontal layer analysis method,the calculation expressions of the seismic non-limit active earth pressure and resultant force point of the wall in the RT mode are derived.The calculation model can describe different non-limit displacement state conditions in which the friction angle gradually develops along the wall height.And the relationship between the displacement of the retaining wall,the seismic load,and the earth pressure is established.The parameter analysis discusses the effects of vibration time,the displacement state of retaining wall,the seismic acceleration parameters and the soil friction angle on the seismic active earth pressure distribution,the resultant force and the height of the resultant action point.Compared with the traditional limit state seismic earth pressure theory,the proposed method describes the development process of seismic earth pressure with retaining wall displacement more reasonably.It has certain reference significance for the development of non-limit earth pressure theory and the improvement of seismic calculation methods in slope engineering.