微型木桩的群桩效应研究  

Study on pile group effect of micro timber piles in soil

作　　者：刘润[1] 彭佳俊 梁超[1] 李成凤[1] LIU Run;PENG Jia-jun;LIANG Chao;LI Cheng-feng(State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学水利工程智能建设与运维全国重点实验室,天津300072

出　　处：《地基处理》2024年第1期23-30,共8页Journal of Ground Improvement

基　　金：国家重点研发计划(2019YFD1101004)。

摘　　要：木材广泛存在于我国村镇中,其取材加工方便,价格低廉,用作村镇住宅的基础结构,可有效减少村镇住宅的能源消耗,符合绿色建筑理念。本文以微型木桩为研究对象,通过离心机模型试验和有限元数值分析,研究了微型木桩在砂土和粉质黏土土层条件下的群桩承载力和群桩效应系数。结果表明,微型木桩的群桩效应系数η在砂土中大于1,在黏土中小于1,受桩土刚度比的影响较小;桩径减小改变了群桩最优桩间距,砂土中微型木桩η随着桩的距径比Sa/D的增大逐渐增大,在Sa/D=6时出现峰值,常规桩在Sa/D=3时达到最大,微型木桩最优桩间距大于常规桩;黏土中,微型木桩η峰值对应的Sa/D=4小于常规桩η峰值对应的Sa/D=6,微型木桩最优桩间距小于常规桩;微型木桩群桩效应系数随内摩擦角和不排水抗剪强度的增大而减小,随距径比的增大先增加后减小,随桩数的增加而增大。Wood is widely used in villages and towns in China.It is convenient for materials processing and cheap.And it can be used as the basic structure of villages and towns housing,which can effectively reduce the energy consumption.The pile group bearing capacity and pile group effect coefficient of micro timber pile group in sand and clay were studied by centrifuge model tests and finite element numerical analysis.The results show that the pile group effect coefficient of micro timber piles is greater than 1 in sand soil and less than 1 in clay soil.The influence of pile-soil stiffness ratio is small and the reduction of pile diameter changes the optimal pile spacing of pile group.In sand and clay,pile group effect coefficient reaches its maximum value when the ratio of distance-to-diameter is 6 and 4,respectively,which is different from the corresponding 3 and 6 in conventional piles.The pile group effect coefficient decreases with the increase of internal friction angle and undrained shear strength.It increases first and then decreases with the increase of distance-to-diameter ratio;and increases with the increase of pile number.

关 键 词：微型桩 木桩 离心机模型试验 群桩效应 数值模拟 

分 类 号：TU473.1[建筑科学—结构工程]