细粒含量对冻土-桩界面剪切特性影响研究  

Study on the Shear Characteristics of Permafrost⁃Pile Interface Influenced by Fine Grain Content

作　　者：胡峻晖 崔宏环 王跃庚 李续靖 HU Junhui;CUI Honghuan;WANG Yuegeng;LI Xujing(Hebei University of Architecture and Engineering,Zhangjiakou 075000,Hebei,China;Hebei Key Laboratory of Civil Engineering Diagnosis,Retrofitting and Disaster Resistance,Zhangjiakou 075000,Hebei,China;Hebei Technological Innovation Center for Assembled Buildings and Underground Engineering,Zhangjiakou 075000,Hebei,China)

机构地区：[1]河北建筑工程学院土木工程学院,河北张家口075000 [2]河北省土木工程诊断、改造与抗灾重点实验室,河北张家口075000 [3]河北省装配式建筑与地下工程技术创新中心,河北张家口075000

出　　处：《力学季刊》2024年第3期842-854,共13页Chinese Quarterly of Mechanics

基　　金：张家口市重点研发计划项目(2322012B);河北省教育厅科学研究项目(CXY2024002)。

摘　　要：针对华北北部地区桩土界面的稳定性开展研究,采用往复直剪仪,在不同法向压力下进行常规直剪试验和往复直剪试验,重点探究了在负温条件下6种细粒含量(0%、10%、20%、30%、40%、50%)对冻土-混凝土界面冻结强度和剪切刚度的影响规律.结果表明:随着细粒含量的增大,常规直剪条件下界面的峰值强度变大,冰胶结强度占比随之提高,且割线模量也不断变大;在往复剪切作用下,界面剪切刚度随剪切循环次数的增加不断衰减,30%细粒含量时界面的剪切刚度衰减幅度最大;虽然细粒的加入会增大界面的剪切刚度,提高界面抵抗变形的能力,但在往复剪切作用下细粒会使界面剪切刚度衰减幅度变大,不利于结构的稳定性.通过层次分析法得出往复剪切次数、细粒含量、环境负温对界面剪切刚度的影响权重分别为58.52%、25.40%、16.08%;该分析结果可为相关工程实践提供参考依据.In order to study the stability of the pile-soil interface in the northern region of North China,a reciprocating straight shear apparatus was used to carry out conventional straight shear tests and reciprocating straight shear tests under different normal pressures,focusing on the changing law of the influence of six kinds of fine-grained contents(0%,10%,20%,30%,40%and 50%)on the frozen strength and shear stiffness of the permafrost-concrete interface under negative temperature conditions.The results show that,with the increase of fine-grained content,the peak strength of the interface under the conventional straight shear condition becomes larger,the proportion of ice cement strength increases and the secant modulus also becomes larger.Under the reciprocal shear,the shear stiffness of the interface at 30%fine content exhibits the largest attenuation.Compared with no fines,the addition of fines makes the shear stiffness of the interface increase.However,under the action of reciprocating shear,fine particles will cause an increase in the attenuation of the interface shear stiffness,which is not conducive to the stability of the structure.Through the analytic hierarchy process,it is concluded that the influential weights of reciprocating shear times,fine grain content,negative environmental temperature on the interface shear stiffness are 58.52%,25.40%,16.08%,respectively.The results of this work can provide scientific basis for the design and construction of the relevant projects.

关 键 词：冻土-结构接触面 往复剪切 剪切刚度 细粒含量 层次分析法 

分 类 号：TU443[建筑科学—岩土工程]