多排微型抗滑桩极限抗滑力的数值模拟研究  

Numerical study of ultimate anti-sliding force of multi-row micro anti-slide piles

作　　者：吴泽雄 雷国平 张院生 苏栋[4,5] 杨伟鸿 马华 程马遥 WU Zexiong;LEI Guoping;ZHANG Yuansheng;SU Dong;YANG Weihong;MA Hua;CHENG Mayao(School of Civil Engineering,Sun Yat-Sen University,Zhuhai 519082,Guangdong,China;School of Civil Engineering and Transportation,Foshan University,Foshan 528225,Guangdong,China;China Academy of Railway Sciences(Shenzhen)Research and Design Institute Co.,Ltd.,Shenzhen 518060,Guangdong,China;College of Civil and Transportation Engineering,Shenzhen University,Shenzhen 518052,Guangdong,China;Underground Polis Academy,Shenzhen University,Shenzhen 518052,Guangdong,China)

机构地区：[1]中山大学土木工程学院,广东珠海519082 [2]佛山大学土木与交通学院,广东佛山528225 [3]铁科院(深圳)研究设计院有限公司,广东深圳518060 [4]深圳大学土木与交通工程学院,广东深圳518052 [5]深圳大学未来地下城市研究院,广东深圳518052

出　　处：《建筑科学与工程学报》2024年第6期171-181,共11页Journal of Architecture and Civil Engineering

基　　金：中国铁道科学研究院集团有限公司基金项目(2019YJ180);深圳市自然科学基金项目(JCYJ20210324094607020);国家自然科学基金项目(51878416);广东省自然科学基金项目(2023A1515011772);佛山市教育局高校教师创新项目(2021XJZZ10)。

摘　　要：对多排微型桩群在土体水平位移作用下的响应开展数值模拟研究,微型桩的建模充分考虑了其塑性变形的特性,并通过对已有的桩抗弯试验建立精细化有限元模型获得了桩体参数。在分析微型抗滑桩响应的基础上,推导了适用于微型抗滑桩的简化极限抗滑力计算公式,研究了微型桩排距和滑动面摩擦因数的影响。结果表明:多排桩能调动相对单排桩更大深度范围的桩土相互作用,结构整体刚度更高,但同时群桩效应降低了桩土相互作用力,多排桩中单桩抗滑力仅为单排桩情况下的50%~70%;滑动面摩擦因数对多排桩的影响大于单排桩,增加该系数明显降低了桩土相互作用力,提高了桩的影响深度范围,导致抗滑力降低;增大排距可整体上提高多排微型桩的抗滑力,当排距小于7倍桩径时,增大排距主要降低了桩的影响深度范围,而当排距大于7倍桩径时,则主要是通过改变桩土相互作用力的分布来增加抗滑力;所提出的桩抗滑承载力计算公式较好地反映了微型桩的受力特征,具有进一步研究和推广的价值。A numerical simulation study was carried out on the response of a multi-row micro-pile group subjected to soil lateral displacement.The plastic deformation characteristics of micro-pile was considered in the numerical model,and the pile parameters were obtained by performing a refined finite element model against some published pile bending tests.Based on the analysis of the micro anti-slide pile response,a simplified formula for calculating the ultimate anti-sliding force was deduced.The influence of the row spacing and the friction coefficient of slip surface were studied.The results show that in the multi-row case,the pile-soil interaction is mobilized in a larger depth range than the case of a single row of piles,and the overall stiffness of structure is higher.However,the pile group effect reduces the pile-soil interaction force.As a result,the anti-sliding force of a single pile in the multi-row structure is only 50%-70%of that of the case of a single-row.The influence of the slip surface friction coefficient is greater on multi-row piles than on single-row piles.Increasing friction coefficient significantly reduces the pile-soil interaction force and increases the pile influencing depth range,which result in the reduction of anti-sliding force of pile.Increasing the row spacing can improve the overall resistance of the multi-row micro-pile structure.When the row spacing is less than 7 times of pile diameter,increasing the row spacing mainly reduces the pile influencing depth range.While the sliding resistance is mainly increased by the variation of the pile-soil interaction force distribution when the row spacing is greater than 7 times of pile diameter.The proposed calculation formula of the bearing capacity of anti-sliding pile can well reflect the force characteristics of the micro-pile,which is worth to be further researched and promoted.

关 键 词：微型抗滑桩 多排桩 弯曲破坏 极限抗滑力 桩排距 

分 类 号：TU473[建筑科学—结构工程]