软土深基坑被动区裙边加固方案优化研究

Research on optimization scheme of skirt reinforcement in passive area for soft soil deep foundation pit

为探究软土深基坑工程中合理的被动区裙边加固方案,本文基于某软土深基坑工程变形实测数据分析,并结合有限元数值模拟方法,系统地分析了被动区裙边加固方案对基坑围护桩变形及深层土体位移场的影响规律。结果表明:1)受加固效果影响最大的是围护桩侧向变形;2)裙边加固体存在有效加固深度和宽度,且当加固宽度设计不足时,仅通过增加加固深度来控制围护结构变形效果不显著;3)裙边加固方案对坑外土体位移场变化影响表现在可有效控制1.0~1.5倍基坑深度范围内土体竖向位移的变化趋势。本文研究成果可为软土地区类似深基坑裙边加固工程提供一定参考。

In order to explore a reasonable reinforcement scheme in passive area skirt for soft soil deep foundation pit engineering,based on the analysis of the measured data of engineering deformation for soft soil deep foundation pit,combined with the method of finite element numerical simulation,the influence of the skirt reinforcement scheme in the passive area on the deformation of the foundation pit enclosure pile and the displacement field of the deep soil is analyzed systematically.The results show that:1)The lateral deformation of the enclosure pile is most affected by the reinforcement effect;2)There is an effective reinforcement depth and width of the skirt reinforcement,and when the reinforcement width design is insufficient,the deformation effect of the enclosure structure is not significant only by increasing the reinforcement depth.3)The influence of the skirt reinforcement scheme on the change of soil displacement field outside the pit is reflected in the effective control of the vertical displacement trend of the soil within the depth of 1.0 to 1.5 times of the foundation pit.The results can provide certain references for similar skirt reinforcement projects for deep foundation pits in soft soil areas.