微型桩-加筋土挡墙应力变形特性的多因素分析  

Multivariate analysis of stress and deformation behavior of micropile-MSE wall

作　　者：张智超[1] 陈育民[2] 刘汉龙[3] 柳侃[1] 叶龙珍[1] ZHANG Zhi-chao CHEN Yu-min LIU Han-long LIU Kan YE Long-zhen(Key Laboratory of Geohazard Prevention of Hilly Mountains, Ministry of Land and Resources of China, Fujian Geological Engineering Survey Institute, Fuzhou, Fujian 350002, China College of Civil ＆ Transportation Engineering, Hohai University, Nanjing, Jiangsu 210098, China Key Laboratory of New Technology for Construction of Cities in Mountain Area, Chongqing University, Chongqing 400045, China)

机构地区：[1]福建省地质工程勘察院国土资源部丘陵山地地质灾害防治重点实验室,福建福州350002 [2]河海大学土木与交通学院,江苏南京210098 [3]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045

出　　处：《岩土力学》2017年第7期1911-1918,1958,共9页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51609040);福建省自然科学基金(No.2016J05112);福建省科技创新平台建设(No.2014Y2007)~~

摘　　要：山区斜坡地带加筋土挡墙的破坏模式为回填土区域沿着边坡产生整体下滑,且回填土强度的降低会更显著地增加挡土墙的变形。针对这种破坏模式,开发了微型桩加固方法,建立了加固前、后的斜坡土挡墙有限元模型,并通过对静载模型试验的数值模拟,对有限元模型的可靠性进行了验证。在此基础上,就自然边坡状况和回填土强度这两个重要因素对微型桩-加筋土挡墙的应力变形特性开展分析。结果表明:微型桩的加固能够有效抑制回填土区域的下滑,根据自然边坡状况的不同,挡土墙位移可较加固前减小6.25%~46.9%,且坡面摩擦角越低,加固前、后的差别越显著;根据回填土强度的不同,挡土墙位移可减小6%~56.1%,且回填土强度越低,减小的比例越大;同时,侧向土压力和回填土的变形也显著降低。其结果可为微型桩-加筋土挡墙在山区公路工程中的实际应用提供指导。Failure mode of mechanically stabilized earth （MSE） wall in slope areas exhibits as the integral sliding of the backfill region along the slope. Particularly, the reduction of backfill strength obviously exacerbates the deformation of the wall. In this study, a novel micropile reinforcement scheme was proposed to investigate this failure mode. Finite element models of MSE wall of the slope before and after reinforcement were established and further validated by scaled model tests. Based on different natural conditions of the slope and the backfll strength, multivariate analysis was performed numerically to compare the stress and deformation behavior of MSE wall before and after micropile reinforcement. The results indicate that the reinforcement of micropiles can effectively prevent the sliding of backfill region along the slope. The displacements of the wall were decreased by 6.25% to 46.9%, according to different natural conditions of backslope. Moreover, the more obvious decrement was found when the backslope friction angle was lower. Based on different backfill strengths, the displacements were reduced by 6% to 56.1%, and the reduction was greater when the backfill strength was lower. In addition, the earth pressure and deformation of backfill soil declined greatly as well. Therefore, the results can provide an important guidance for the application of micropile-MSE wall in the practical engineering of road construction in mountainous areas.

关 键 词：加筋土挡墙 数值模拟 应力变形特性 微型桩 模型试验 

分 类 号：TU476.4[建筑科学—结构工程]