回填土夯实效果与挡墙高度对加固边坡失效概率的影响

Influence of Backfill Compaction Effect and Height of Retaining Walls on Failure Probability of Reinforced Slopes

为了评估加固边坡的稳定程度并优化挡墙高度,提出通过改变夯填粗颗粒土内摩擦角的变异系数间接考虑施工质量不确定性的方法;采用Geo-Studio软件建立加固边坡模型,并应用Morgenstern-Price法计算边坡的安全系数,基于Win-Batch TM语言实现蒙特卡罗抽样,计算不同变异系数时加固边坡的失效概率;结合光滑粒子流体动力学方法,研究挡墙高度对加固边坡失效概率的影响;将所提出的方法在哈佳铁路加固边坡中进行应用。结果表明:在施工中提高施工质量以减小夯填土的参数变异性可以有效降低加固边坡的失效概率;增加挡墙高度可以有效阻隔滑动土体滑落至铁路线,显著降低边坡失效概率;当变异系数为0.4并且未加高挡墙时,失效概率为27.2%;当挡墙高度增加1 m时,失效概率降为2.58%;在变异系数小于0.4的条件下,挡墙高度增加1 m时加固边坡失效概率的降低程度更明显。

To evaluate stability of reinforced slopes and optimize height of retaining walls,a method indirectly considering uncertainty of construction quality through changing coefficients of variation of internal friction angles of compacted coarse-grained soil was proposed.Geo-Studio software was used to establish a reinforced slope model,and Morgenstern-Price method was used to calculate slope safety factors.Monte Carlo sampling was implemented based on Win-Batch TM language,and failure probability of reinforced slopes with different coefficients of variation was calculated.Influence of height of retaining walls on failure probability of reinforced slopes was researched by using smoothed particle hydrodynamics method.The proposed method was applied in slope reinforcement of Harbin-Jiamusi railway.The results show that improving construction quality to reduce coefficients of variation of soil parameters can effectively reduce failure probability of reinforced slopes during construction.Increasing height of retaining walls can effectively prevent sliding soil from sliding to the railway line,thus significantly reduce failure probability of slopes.When the coefficient of variation is 0.4 and the retaining wall is not heightened,the failure probability is 27.2%.The failure probability reduces to 2.58%if the height of retaining walls is increased by 1 m.When the coefficient of variation is less than 0.4,the reduction degree of slope failure probability caused by increasing height of retaining walls by 1 m is more obvious.