深厚换填砂土地基强夯有效加固深度的影响因素

Influencing factors of effective reinforcement depth by dynamic compaction on deep replacement of sand soil foundation

为研究不同因素对强夯有效加固深度的影响,结合某地基处理项目的现场重型动力触探(DPT)检测试验,应用ABAQUS软件建立深厚换填砂土地基强夯法施工的数值计算模型,模拟分析了施工参数与土体参数对强夯有效加固深度的影响。结果表明:换填砂土地基强夯有效加固深度受夯击能、锤径、夯击次数及夯击能组合形式的影响较大,且随夯击能、夯击次数的增大而增大,随锤径(D≥2.0 m)的增大而减小;在夯击能不变的条件下,应优先选取重锤低落施工方案。强夯有效加固深度随土体内摩擦角、密度、泊松比、弹性模量的增大而线性减小,且泊松比与密度对有效加固深度的影响较大,内摩擦角与弹性模量对有效加固深度影响较小。

This paper aims to study the influence of different factors on the effective reinforcement depth by dynamic compaction.The study is accomplished by combing with the field heavy dynamic penetration test(DPT)of a foundation treatment project;establishing a numerical calculation model of dynamic compaction construction of deep replacement of sand foundation by using ABAQUS software,simulating and analyzing the influence of construction parameters and soil parameters on the effective reinforcement depth of dynamic compaction.The results show that the effective reinforcement depth of dynamic compaction of sand foundation replacement is greatly affected by the combination forms of tamping energy,hammer diameter,tamping times and tamping energy,and increases with the increase of tamping energy and tamping times,and decreases with the increase of hammer diameter(D≥2.0 m).Under the condition of constant tamping energy,the low dropping construction scheme of heavy hammer should be preferentially selected.The effective reinforcement depth of dynamic compaction decreases linearly with the increase of internal friction angle,density,Poisson′s ratio and elastic modulus of soil,and Poisson′s ratio and density have a great influence on the effective reinforcement depth,while internal friction angle and elastic modulus have little influence on the effective reinforcement depth.