加筋土挡墙土压力计算方法

Earth pressure computation method of reinforced earth retaining wall

为了合理计算加筋土挡墙的土压力,分析了加筋土挡墙施工过程中墙后填料的填筑和碾压次序与填料的压实度,通过建立墙面板内侧一定范围内填料变形体微单元的静力平衡方程,导出了墙面板土压力表达式。结果发现当墙后反滤层为砂砾料时,土压力随着墙高的增大而逐渐变大,但最终趋于一个确定值,计算的土压力值比朗金主动土压力值小,随着反滤层厚度的加大,土压力值变大,越接近于朗金主动土压力值;反滤层为砂砾料并混有一定的粘性土时,随着反滤层厚度的变小,土压力为负值的范围变大,说明墙面板相当多的部分仅起构造作用,当反滤层厚度增大到某一值时,墙后填土才表现为压应力,这与实际测量土压力趋势一致,说明此方法可行。

In order to reasonably compute the earth pressure, the order of filling and compacting earth behind reinforced earth retaining wall was analyzed, the compacting factors and deformations of backfills behind the wall were studied, the static equilibrium equation of differential earth unit in definite width was set up, and a formula of earth pressure acting on the surface of the wall was gained. When inverted filter is made of sandy gravel, the earth pressure gets bigger gradually along the wall from top to bottom, and finally tends to stable value, it is smaller than Rankine earth pressure. When inverted filter is made of sandy gravel mixed with clayey soil, the thinner inverted filter is, the smaller earth pressure is, when it reaches to a certain thickness, the earth pressure becomes negative, which indicates that some of wall faces be not forced, they possess structural function. The results show that the varying trend of earth pressure accords with the real measure result, the mothed is feasible.