微型钢管桩计算方法优化分析及应用研究

Optimization analysis and application research on calculation methods for micro steel pipe piles

微型钢管桩在滑坡、基坑等领域应用越来越广泛。结合贵州习水某滑坡应急治理项目,利用现有设计计算理论按沿滑面的抗剪计算桩的排数、桩身内力以及嵌固深度,选择合适的桩径及壁厚,结合桩水平承载力特征值计算公式进行验算,最终完成该项目支护设计工作。现有计算理论未考虑桩砂浆体抗剪强度,偏于保守,本次设计将砂浆体抗剪考虑在内,优化了设计并减少了工程量,并提出采用由位移控制性的水平承载力特征值进行验算。通过对桩顶位移进行长期监测,证明钢管桩支护设计工作达到了阻滑的目的,滑坡在支护后处于稳定状态。

Micro steel pipe piles are increasingly widely used in fields such as landslides and foundation pits.Some practical method and theory for calculation on micro steel pipe piles are proposed but not yet formed a uniform cognition.The number of pile rows and internal force and embedded depth are calculated by the shear resistance along the sliding surface through the design calculation theory and the appropriate pile diameter and steel pipe wall thickness are selected,calculation of characteristic values of horizontal bearing capacity of piles is checked,eventually completed design work.The existing calculation theory does not consider the shear strength of the pile mortar body,which is conservative.In this design,the shear strength of the mortar body is taken into account,and the design is optimized and the engineering quantity is reduced.It is proposed to use displacement controlled horizontal bearing capacity characteristic values for verification.By long-term monitoring of pile top displacement,the steel pipe pile support design has achieved the goal of preventing sliding and the landslide was in stable state after treating.