地震作用下挡土墙主动土压力分布  

Seismic active earth pressure of retaining wall

作　　者：张永兴[1] 陈林[2] 

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]德国斯图加特大学岩土工程研究所,德国斯图加特70569

出　　处：《深圳大学学报（理工版）》2012年第1期31-37,共7页Journal of Shenzhen University(Science and Engineering)

基　　金：国家自然科学基金资助项目(50878218);国家杰出青年科学基金资助项目(50625824)~~

摘　　要：在滑动楔体上沿竖向取水平薄层作为微分单元体,通过作用在单元体上的水平力、竖向力及地震力,建立挡土墙主动土压力基本方程,结合滑楔体力矩平衡条件,得到对应不同地震系数的侧压力系数,将其用于水平微分单元法,得到了地震荷载作用下挡土墙主动土压力理论公式.分析地震系数对土侧压力系数和土压力的影响,结果表明,土侧压力系数随水平地震系数增加而增大;当竖向地震系数小于零时,土侧压力系数随竖向地震系数增大而减小,当竖向地震系数大于零时,土侧压力系数随竖向地震系数增大而增大;随着竖向地震系数的增大,水平土压力强度最大值逐渐减小,随着水平地震系数的增大,水平土压力强度最大值先递减后增大;随着竖向及水平地震系数的增大,水平土压力最大值位置向墙顶方向移动,靠近墙底处土压力强度相对减小,靠近墙顶处土压力强度相对增大.The basic analysis equations were set up by considering the equilibrium of the forces on a thin-layer element of the wedge. By using the equilibrium equation of the moments on the whole wedge, the lateral coefficient of earth pressure, and the earth pressure distribution along the wall were obtained. The effects of seismic coefficient on the lateral coefficient of earth pressure and the distribution of earth pressures were investigated. The results show that the lateral earth pressure coefficient increases as the horizontal seismic coefficient increases. The effect of the vertical seismic coefficient is more complicated. If the vertical seismic coefficient is less than zero, the lateral earth pressure coefficient decreases as the vertical seismic coefficient increases; If the vertical seismic coefficient is greater than zero, the lateral earth pressure coefficient increases as the vertical seismic coefficient increases; the maximum earth pressure gradually decreases as the vertical seismic coefficient increases. The maximum earth pressure first decreases and then increases as the horizontal seismic coefficient increases; as the increase of the vertical and horizontal seismic coefficient increases, the position of the maximum lateral seismic earth pressure moves gradually to the top of the wall, but near the bottom of the wall, the relative value of the earth pressure decreases, and near the top of the wall, the relative value of the earth pressure increases. Theproposed method was verified agree well with the experiment earth pressure was investigated by some experiment data. The calculated resultant and maximum earth pressure results~ The effect of seismic coefficient on the points of application of the resultant earth pressure was investigated. The proposed method was compared with the Mononobe-Okabe＇s theory. The resuhs indicate that it is dangerous for the overturning stability of retaining walls with the translational movement mode if the~ are designed according to the Mononobe-Okabe＇s theory.

关 键 词：岩土工程 主动土压力 侧压力系数 刚性挡土墙 合力作用点 倾覆力矩 

分 类 号：TU432[建筑科学—岩土工程]