垂直挡墙上土压力计算方法的拓展

结合莫尔圆将基于Rankine理论的经典土压力计算公式推广至更为普遍的形式,通过极限平衡理论在数学形式上对其进行了验证,并分析了土中含水率的变化对土压力的影响。结果表明,在Rankine理论基本假设的前提下,其主动土压力方向平行于填土表面的假定是合理的,当填土表面水平时,能够回归到Rankine理论的经典公式,表明了其正确性。挡土墙实际作用土体大都处于非饱和状态,其基质吸力随土体含水率的增加而减小,含水率为零时,主动土压力最小,被动土压力则最大;含水率增大至饱和状态时,主动土压力最大,被动土压力最小,因此,含水率变化引起的土体体积变化对挡土墙上土压力有很大影响。

Extension of Calculation Method of the Earth Pressure on Retaining Wall

A more general style of the formula about classical earth pressure on the retaining walls based on Rankine theory is proposed through Mohr circle and tested in mathematic form through limit equilibrium theory and the influence of water content variation on the earth pressure is analyzed.It is concluded that,rationality about the direction of active earth pressure is indicated when the basic assume is followed as in Rankine's theory and correctness of the suggested method is shown by successful regression to the classical form of Rankine theory.The soil acted on the wall is basically in non-saturated state and the suction of the soil decreases as the water content increases.The active earth pressure is minimum while the passive is maximum when water content is zero and the former get maximum in the saturated soil while the latter minimum.The volume change of the soil due to water content change has great influence on the earth pressure of the retaining walls.