列车振动荷载作用下隧道周边软黏土长期沉降分析  

Analysis of long-term settlement of soft clay under train vibration

作　　者：葛世平[1,2,3] 姚湘静[1,2,3] 叶斌[1,2] 蒲黍絛 刘学增[4] GE Shiping YAO Xiangjing YE Bin PU Shutao LIU Xuezeng(Department of Geoteehnical Engineering, Tong/i University, Shanghai 200092, China Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092, China Shanghai Shentong Metro Group Co., Ltd., Shanghai 201102, China Civil Engineering Information Technology Research Center of Ministry of Education, Tongji University, Shanghai200092, China)

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092 [3]上海申通地铁集团有限公司,上海201102 [4]同济大学土木信息技术教育部工程研究中心,上海200092

出　　处：《岩石力学与工程学报》2016年第11期2359-2368,共10页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点基础研究发展计划(973)项目(2015CB057806);国家自然科学基金资助项目(51278377)~~

摘　　要：以上海地铁9号线三期工程为背景,对隧道周边1.5倍隧道外径范围内土体长期沉降进行现场监测。为分析上海软黏土在列车长期循环动荷载下的变形特征,通过引进考虑长期循环荷载作用效应的控制参数对现有动力循环加载弹塑性本构模型进行改进;采用改进的本构模型分析列车振动、工后固结2种工况下软黏土沉降发展规律。结果表明:通车850 d后,隧道拱底相对于地面的沉降实测值为4.7 mm,计算值为4.6 mm,其中由列车振动引起的沉降为3.1 mm,误差为2.0%,表明改进后的本构模型能够较好地模拟软黏土在列车振动荷载下的累积变形特征;振动荷载下隧道长期沉降符合指数型增长规律;在隧道埋深13.2 m情况下,列车振动引起的隧道拱底相对于地面的沉降经过约8 a趋于稳定,稳定后相对沉降量为4.2 mm。The long-term soil settlement was monitored around a tunnel within the range of 1.5 times of the outer diameter of the tunnel of Metro line 9 in Shanghai. A parameter was introduced into an existing dynamic elasto-plastic constitutive model to take into account the effect of long-term cyclic loading. The development of soft clay settlement caused by the train vibration and post-construction consolidation was calculated using the improved constitutive model. The measured settlement of the tunnel invert relative to the ground is 4.7 mm after 850 days of tunnel operation. The calculated settlement is 4.6 mm with the vibration-induced settlement to be 3.1 mm. The difference of measured and calculated settlements is 2%,indicating that the improved constitutive model shows a satisfactory performance on simulating the accumulated deformation characteristics of soft soil under the vibration load. The long-term settlement of the tunnel is in accordance with the exponential growth law with time. In the case of tunnel depth at 13.2 m,the relative settlement of arch bottom tends to be stable after about 8 years,and the relative settlement is 4.2 mm after stability.

关 键 词：土力学 软黏土 列车振动 本构模型 长期沉降 

分 类 号：TU43[建筑科学—岩土工程]