非线性被动土压力

Nonlinear passive earth pressure

用双曲线数学模型描述被动土压力变化和挡土结构位移变化的关系。基于Mindlin弹性解,推导了土体某深度矩形区域作用均布水平荷载时该矩形区域内任意点水平位移的表达式,并用该表达式确定双曲线模型初始刚度。应用对数螺旋线被动土压力理论求解被动土压力,把该法求解的做图过程转化为数学迭代过程。算例表明,这样的被动土压力理论概念明确,结果准确。

The nonlinear relationship between the passive earth pressures and retaining wall deflection is approximated using the general form of a hyperbolic equation. Based on the Mindlin elastic solution, an equation is integrated for the horizontal displacement of any point of a vertical plane when a rectangular area with the plane is subjected to uniform normal loading. The equation can compute the initial stiffness of hyperbola. The Log Spiral theory is employed in computing the ultimate passive earth pressure which is one of the parameter of hyperbola. The predicted results from the hyperbola match well the measured passive earth pressures.