临河基坑有限成层土体主动土压力计算

Calculation of Active Earth Pressure of Limited Layered Soil of Foundation Pit Near River

为探究临河基坑有限成层土体主动土压力的大小,以开挖基坑与河流之间的有限土体为研究对象,通过研究有限土体滑裂面的不同情况,得出了不同情形下的主动土压力表达式。通过算例分析,验证了公式的准确性。结果表明:均布荷载并不会对有限成层土体主动土压力的变化趋势产生影响,改变的只是数量的大小;开挖基坑临河距离对于较浅的开挖基坑影响较小,而随着基坑深度的增加,不同临河距离对应的有限土体主动土压力合力之间的差距逐渐加大,但最终趋于稳定;分层土条件下的主动土压力合力与嵌固深度呈正比例关系,同增同减。同时,随着基坑开挖深度的增加,嵌固深度对于主动土压力合力的影响也越来越显著,在开挖基坑较浅时,嵌固深度对于主动土压力合力的影响相对较小。

In order to explore the active earth pressure of the limited layered soil of the foundation pit near the river,the limited soil between the excavated foundation pit and the river was taken as the research object.By studying the different situations of the finite soil slip surface,the active earth pressure expressions under different situations were obtained.Through the analysis of numerical examples,the accuracy of the formula was verified.The results show that the uniform load will not affect the change trend of the active earth pressure of the finite layered soil,but only the quantity.The distance between the excavated foundation pit and the river has little effect on the shallower excavated foundation pit.As the depth of the foundation pit increases,the gap between the active earth pressure results of the finite soil mass corresponding to different riverside distances is gradually increasing,but it tends to stabilize at last.The resultant active earth pressure and the embedded depth of the layered soil are positive proportional relationship and they have the same increase and decrease.Meantime,with increasing depth of excavation,the impact of the embedded depth on the resultant active earth pressure becomes more and more conspicuous.When the excavation of the foundation pit is shallow,the impact of the embedded depth on the resultant active earth pressure is relatively small.