基于模型不确定的挡墙土压力计算

发布时间：2018-07-02 23:26

本文选题：刚性挡土墙 + 土压力　；参考：《岩土工程学报》2017年04期

【摘要】：基于模型不确定性土压力问题,从滑动土体整体静力平衡方程出发,推导了一般情况下土压力泛函极值等周模型,包含了主动和被动极限状态两种情况。通过引入坐标变换对土压力变分问题进行求解,得到了滑裂面函数和沿滑裂面分布的法向应力函数,将土压力的求解进一步转化为以两个拉格朗日常数为未知量的函数的极值问题。在函数Ф随作用点位置系数ξ的变化曲线中,可以找到一段Ф=0的水平直线段,此直线段即为合理作用点位置系数范围,由此可以确定对应的土压力范围。通过算例对主动和被动两种情况予以说明。计算表明,作用点位置系数存在上下界限值,且分别对应土压力最大值和最小值及对应的滑裂面。土压力的大小和作用点位置依赖于挡墙变位模式,作用点位置系数上下限处所对应的土压力构成的数值范围,包含了各种挡墙变位模式下的土压力。通过本文提出的方法可以得到挡墙不同变位模式下,土压力大小和作用点位置的区间估计,以便为工程设计人员选用。
[Abstract]:Based on the model uncertainty of soil pressure problem, based on the static equilibrium equation of the sliding soil, the extreme value equivalent cycle model of the soil pressure functional is derived, which includes two cases of active and passive limit state. By introducing the coordinate transformation to solve the soil pressure variation problem, the slip surface function and the distribution along the sliding surface are obtained. In the normal stress function, the solution of the earth pressure is further converted to the extreme value problem of a function with two Lagrange constants as the unknown quantity. In the change curve of the position coefficient of the function point, the horizontal line segment of the =0 can be found. This line section is a reasonable point position coefficient range, thus the correspondence can be determined. Two cases of active and passive conditions are illustrated by an example. The calculation shows that the position coefficient of the action point has the upper and lower boundary values and corresponding to the maximum and minimum values of earth pressure and the corresponding sliding surface. The size of the earth pressure and the position of the action point depend on the retaining wall displacement mode and the upper and lower limit of the position coefficient of the action point. The numerical range of the corresponding soil pressure consists of the earth pressure under various retaining walls. The method proposed in this paper can be used to estimate the size of the earth pressure and the location of the point of action in different displacement modes of the retaining wall, so as to be selected for the engineering designers.
【作者单位】：重庆大学土木工程学院;山地城镇建设与新技术教育部重点实验室(重庆大学);
【基金】：国家自然科学基金项目(51478065)
【分类号】：TU476.4

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