多级重力式挡土墙土压力分布试验研究

对某高填方路基挡土墙的现场实测水平土压力数据进行了分析,研究表明:该挡墙墙后土压力呈曲线分布,类似字母"R",土压力最大值出现在挡墙底部,而下部的值略小于底部值,最小值出现在挡墙中部。在本级挡墙施工时,墙后第1、2层土压力值接近静止土压力值,大于主动土压力值,第3、4层土压力值小于主动土压力值;在其上若干级挡墙或边坡施工时墙后各点土压力值均小于主动土压力值,即随着填土深度的变化挡墙后各点的土压力系数是在不断变动着的,土压力系数与土压力数值大小的变化规律一致。同时,土压力作用点介于(0.4～0.5)H,且随填土深度增加作用点位置上移;每级挡土墙之间的平台宽度越小,上级挡土墙对下级挡土墙的影响就越大,土压力作用点就越高。研究结论对高填方多级挡土墙的设计具有理论指导意义。

Experimental study of earth pressure distribution of multistage gravity retaining walls

By analyzing the actual earth pressure of certain multistage gravity retaining walls, the horizontal earth pressure distributed situation can be described as “R”; the lower earth pressure is less than the bottom value, the bottom value is maximal and the middle is minimum. When the shelf-wall construction the actual earth pressure at the first and second layer is close to the resting earth pressure and more than the active earth pressure; while the third and forth layers is less than the active earth pressure; on the other hand, the pressure at all layers are less than the active earth pressure while the upper wall(s) and slope constructed. The coefficient of earth pressure changes with the filled increased, which is accordantly with the value of the earth pressure. Simultaneity, the position of the action point of the earth pressure is from 0.4H to 0.5H; and it is upper shift along with the earth fill depth; the smaller the platform width between each single wall, the bigger the upper wall influence on the subordinate wall; the higher earth pressure action point. This conclusion has good theoretical guiding sense to the multistage retaining wall designs.