考虑沉降控制条件的群桩可靠度分析  

Reliability analysis of pile groups considering settlement control requirements

作　　者：边晓亚[1] 郑俊杰[1] 徐志军[2] 章荣军[1] 

机构地区：[1]华中科技大学土木工程与力学学院,武汉430074 [2]河南工业大学土木建筑学院,郑州450052

出　　处：《东南大学学报（自然科学版）》2015年第4期782-786,共5页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51278216;51478201);湖北省自然科学基金面上资助项目(2013CFB180);河南工业大学高层次人才基金资助项目(2013BS010)

摘　　要：考虑群桩效应和系统效应的影响,利用定义的正常使用极限状态模型因子,给出反映沉降控制条件影响的群桩承载力综合偏差系数,并结合单桩承载力可靠度方法提出考虑沉降控制条件的群桩可靠度综合分析方法.利用已有资料,研究了土体性质、桩型、承台、系统效应和容许沉降对群桩可靠度分析结果的影响.结果表明:无黏性土、低承台条件下群桩的可靠度指标比黏性土、高承台条件下群桩的可靠度指标大;群桩可靠度指标随系统效应系数的增大呈现出明显增加的趋势;群桩可靠度指标随沉降控制条件的放宽逐渐增大,但增大幅度逐渐降低.Considering pile group effect and system effect and utilizing the model factor defined for serviceability limit state （ SLS）, a synthetic bias factor of bearing capacity of pile groups is proposed considering the settlement control requirements. According to the reliability analysis method of bear- ing capacity of single piles, a synthetic reliability analysis method of pile groups with consideration of settlement control requirements is presented. Based on the obtained data sources, the impacts of soil properties, pile types, pile cap types, system effect, and limiting tolerable settlement on reliabil- ity of pile groups are studied. The results indicate that the reliability indices of pile groups with ground contact caps in cohesionless soils are greater than those with freestanding caps in cohesive soils; the reliability index of pile groups significantly increases with the system effect factor; the reli- ability index of pile groups increases with the softening of settlement control requirements, however the increase rate ~raduallv diminishes.

关 键 词：群桩 可靠度 沉降控制条件 群桩效应 系统效应 

分 类 号：U414[交通运输工程—道路与铁道工程]