摘要
桩与土的空间作用效应,使长短桩复合地基承载性能与单桩承载性能之间存在显著差异。通过现场静载试验和三维数值计算,对长短桩复合地基承载性能进行了研究分析。结果表明:长短桩复合地基静载试验中,3.5 m管桩的桩土应力比在2到3之间,而5.5 m管桩的桩土应力比在6到8之间;随着桩数的增加,四桩复合地基变形沉降值要大于等同条件下单桩复合地基的变形沉降值;长短桩群桩效应系数为0.616,长短桩复合地基可以弱化群桩效应;随着桩数和桩长的增加,桩土应力比随之增大。受刚性基础下的影响,复合地基中长桩的桩土应力比相对较大,降低了桩间土体受到的荷载值,从而使复合地基整体变形沉降值较小。研究成果可以为相关工程技术人员提供参考。
The spatial effect of pile and soil makes the difference between the bearing capacity of long and short pile composite foundation and the bearing capacity of single pile. In this paper,the bearing capacity of long and short pile composite foundation is studied and analyzed by field static loading test and three-dimensional numerical calculation. The results show that the length of the pile composite foundation static load test,pile soil stress ratio of 3. 5 m pile in between 2 to 3,and the pile-soil stress ratio of 5. 5 m pile in between 6 to 8; with the increase of the number of piles,four piles composite foundation settlement value is greater than the equivalent single pile composite foundation deformation sedimentation value; length of the pile group effect coefficient is 0. 616,long short pile composite foundation can weaken the effect of pile group; with the number of piles and pile length increases,pile-soil stress ratio increases. Under the influence of the rigid foundation,the pile-soil stress ratio of the long pile in the composite foundation is relatively large,and the load value of the soil between the piles is reduced,so that the settlement of the composite foundation is smaller. The research results can provide reference for relevant engineers and technicians.
出处
《公路工程》
北大核心
2018年第1期114-117,共4页
Highway Engineering
基金
国家自然科学基金项目(51278218)
关键词
长短桩
复合地基
沉降
应力比
试验研究
数值模拟
long and short piles
composite foundation
settlement
stress ratio
experimental study
numerical simulation
