黄土地基微型桩水平承载力及群桩效应研究

Horizontal bearing capacity and pile group effect of micro-pile on loess ground

为了明确黄土地基微型桩水平承载力对上部结构安全性能的影响,本研究基于黄土地基微型桩现场静载试验,研究了桩长、桩径、桩身弹性模量及桩间距对微型桩水平承载力的影响;分析了沿基础深度的桩身水平位移和弯矩变化规律。并结合有限元分析了桩间距对群桩水平承载力的影响。研究结果表明:黄土地基微型桩基础弯矩较大的位置距桩顶4d~5d;桩径对微型桩水平承载力的影响较大,而桩长超过33d~35d后对其水平承载力的影响较小;当桩间距达到8d时,可以不考虑群桩效应对群桩水平承载力的影响。上述研究成果为微型桩在黄土地基中的应用提供了参考。

In order to clarify the influence of horizontal bearing capacity of micro-piles on superstructure safety performance,the effects of pile length,pile diameter,pile elastic modulus and pile spacing on horizontal bearing capacity of micro-pile on loess foundation are studied based on in-situ static load test.The variation of pile displacement and bending moment along the foundation depth under different horizontal loads are analyzed.And the influence of pile spacing on the horizontal bearing capacity of pile groups is analyzed with the aid of the verified finite element model.The results show that the position of the greater bending moment of micro-pile foundation on loess soil is about 4d-5d from pile top.The pile diameter has a greater impact on the horizontal bearing capacity of the micro-pile,but the influence is relatively small when the pile length exceeds the optimal pile length(33d-35d).When the pile spacing reaches 8d,the influence of the pile group effect on the horizontal bearing capacity of the pile group can be ignored.The above research results provide some reference for the application of micro-pile on loess foundation.