基于离心模型试验的软基路堤基底压力和垫层筋带拉力分析

Analysis of tensile force in reinforced cushion and pressure at bottom of soft soil foundation embankment based on centrifugal model tests

为掌握垫层结构性能对基底压力和垫层筋带拉力的影响,设计了3种不同垫层结构的软土地基路堤离心模型试验,测试了在路堤荷载作用下的基底压力和垫层筋带拉力等数据。试验数据及分析表明,(1)随垫层结构性增强,路堤中心处的基底压力逐渐减小,路基面范围的基底压力分布由"中大边小"的凸型曲线逐渐变为"中小边大"的凹型曲线;(2)随垫层结构性的降低垫层筋带拉力减小,路堤土体也由静止稳定状态变为主动极限状态;(3)随路堤荷载增加,地基土体状态由弹性进入弹塑性直至塑性屈服,垫层筋带拉力的分布也逐渐由双峰的马鞍型向单峰的抛物线型转变。

Three groups of soft soil foundation embankment centrifugal model tests,separately with different types of cushion were designed to master the effect of reinforced cushion on the pressure at the bottom of embankment and the tensile force in reinforced cushion.Test results show as follows.（1） With the enhancement of reinforced cushion＇s structural performance,the pressure at the center of embankment bottom decreases gradually and the distribution of the pressure at the bottom of embankment changes from convex curve which is large in the middle section but small at the two ends to concave curve which is small in the middle section and large at the two ends.（2） With the reduce of reinforced cushion＇s structural performance,embankment changes from quiescent stable state to active limit state.（3） With the increase of embankment load,foundation changes from elastic state to elastoplastic state and up to plastic state.the distribution of tensile force in reinforced cushion changes from the shape of saddle with two peak to the shape of parabola with one peak.