地震条件下倾斜挡土墙被动土压力研究

挡土墙的抗震设计是减小地震灾害的一项重要措施。在Mononobe-Okabe平面滑裂面假设的基础上,将随机出现的地震力按最不利工况下的静力考虑,利用水平层分析法得到了地震加速度沿墙高均匀分布时不同挡土墙倾角、填土摩擦角、墙背摩擦角下的地震被动土压力系数、被动土压力强度、被动土压力合力和被动土压力合力作用点的理论公式。分析了地震加速度系数、挡土墙倾角、填土内摩擦角对被动土压力系数和土压力分布的影响,结果表明,地震被动土压力合力与Mononobe-Okabe理论相同,地震土压力强度为非线性分布。在最不利工况下,地震力的出现大大减小了被动土压力,减小的程度随地震加速度的增加而增加。

Passive earth pressure of inclined retaining walls under seismic condition

Earthquake-resistant design of the rigid retaining walls is a very important measure to minimize the devastating effect of earthquake hazards.Based on the planar rupture surfaces hypothesis of Mononobe-Okabe theory,a method of horizontal slices is suggested to obtain the seismic passive earth pressure coefficient,the intensity of earth pressure,the resultant force of earth pressure and the application point of the resultant for various wall batter angles,soil friction angles and wall friction angles by considering the random occurrence seismic forces as a pseudo-static manner under the most unfavorable conditions.The effects of seismic acceleration coefficients,batter angles and the soil internal frictional angles on the passive earth pressure coefficient and distribution of passive earth pressure are investigated.The results show that the resultant seismic earth pressure is the same as that obtained by the Mononobe-Okabe approach and the distribution of seismic earth pressure is non-linear.The presence of seismic forces induces a considerable reduction in the passive earth resistance under the most unfavorable conditions.The reduction increases with the increase of the magnitude of the earthquake acceleration.