松散体滑坡抗滑桩加固的土拱效应分析  

Soil Arching Effect Analysis of Anti-slide Piles in Loose Media Landslide

作　　者：詹永祥[1] 姚海林[1] 董启朋[1] 王家强[2] 贺东平[3] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,武汉430071 [2]江苏交通科学研究院股份有限公司,南京210017 [3]中国水电顾问集团昆明勘测设计研究院勘察分院,昆明650041

出　　处：《上海交通大学学报》2013年第9期1372-1376,1389,共6页Journal of Shanghai Jiaotong University

基　　金：国家重点基础研究发展规划(973)项目(2013CB036405);交通运输部建设科技项目(2011318775680);中国科学院重点部署项目(KZZD-EW-05)资助

摘　　要：基于颗粒流理论,采用PFC^(2D)程序对抗滑桩加固的松散体滑坡成桩后的土拱形成、发展及破坏过程进行研究,分析细观因素(摩擦系数和孔隙率)对抗滑桩土拱效应的影响.结果表明:抗滑桩第1次产生的土拱效应承担极限承载力;土拱破坏后,后续产生的土拱效应承担残余承载力,残余承载力虽有波动但变化不大;桩间土拱的极限承载力、残余承载力和桩体最大荷载分担比随着抗滑桩的桩间净距离增大而减小,随着桩宽增加而增大,但其变化关系并非简单的线性关系;在一定范围内,摩擦系数对抗滑桩土拱效应的影响较大,土体摩擦系数越大,土拱效应越明显,土拱极限承载力越大,且桩体最大荷载分担比呈增长趋势;颗粒集合体的孔隙率对抗滑桩成拱的影响显著,密实度低的松散体的土拱极限承载力相当于密实度高的松散体的残余承载力.Based on particle flow theory, the process of formation, development, destruction and re-forma- tion of the soil arching in loose media landslide were systematically studied by using PFC2D program to ana- lyze the effect of meso-mechanical parameters such as friction coefficient and porosity on pile-soil interac tion characteristics. The results show that the soil arching produced by the anti-slide pile for the first time bears the ultimate bearing capacity~ after the destruction of the soil arching, subsequent formation of the soil arching effect bears the residual capacity~ the value of residual capacity fluctuates, but within a certain limit~ the ultimate bearing capacity, the residual capacity and the maximum pile load distribution ratio de- crease with the increase of pile clear spacing, and increase with the increase of pile width, yet the relation is not a linear one the soil arching effect is greatly affected by the friction coefficient within a certain limit, and as the friction coefficient increases, the effect is more significant, the ultimate bearing capacity of soil arching is larger, and the maximum pile load distribution ratio tends to increase; soil arching effect is sig- nificantly affected by the porosity of particle aggregate, and the soil arch ultimate bearing capacity of low density loose landslide is equivalent to the residual capacity of high density loose landslide.

关 键 词：松散体滑坡 抗滑桩 土拱效应 颗粒流 细观 

分 类 号：TU473.1[建筑科学—结构工程]