地震作用下软基加筋土路堤变形破坏模式研究  

Deformation and Failure Mode Study of Reinforced Subgrade with Soft Foundation under Earthquake

作　　者：蒋楚生[1] 丁子豪 邹川 赵晓彦[3] JIANG Chusheng;DING Zihao;ZOU Chuan;ZHAO Xiaoyan(China Railway Eryuan Engineering Group Co.Ltd,Chengdu,Sichuan 610031,China;China Railway First Survey and Design Institute Group Co.Ltd,Xi'an,Shaanxi 710043,China;Southwest Jiaotong University,Chengdu,Sichuan 610031,China)

机构地区：[1]中铁二院工程集团有限责任公司,成都610031 [2]中铁第一勘察设计院集团有限公司,西安710043 [3]西南交通大学,成都610031

出　　处：《铁道工程学报》2021年第6期37-41,共5页Journal of Railway Engineering Society

基　　金：国家自然科学基金项目(41672295)。

摘　　要：研究目的:孟加拉达卡铁路沿线广泛分布三角洲相及冲积相软黏土,软土层深厚且土体力学性质较差。根据孟加拉地震资料,达卡铁路部分区段处于设计地震加速度0.15g的较高地震烈度区域。针对软土基础在地震作用下的力学响应,当前研究多集中于山间土石坝和浅海低矮路堤,对地震作用下深厚软基加筋土铁路路堤的变形破坏模式进行研究有其必要性。研究结论:(1)基于国际通用有限元软件Plaxis对地震作用下深厚软基加筋土铁路路堤的稳定性及变形破坏模式进行数值模拟研究,结果表明在当前地震加速度下,采用过高强度的土工布将产生浮托效应,使路堤本体发生整体滑动;(2)受浮托效应影响,土工布不能有效发挥其抗拉强度,软基路堤稳定性主要由力学性质较差的地基软土承担;(3)本研究成果可为高地震烈度区的深厚软基铁路路基处理提供参考。Research purposes: Delta and alluvial soft clays are widely distributed along Dhaka railway in Bangladesh, with deep layer and poor mechanical properties. According to the seismic data of Bangladesh, some sections of Dhaka railway are located in the high seismic intensity area with the design seismic acceleration of 0.15g. In view of the mechanical response of soft soil foundation under earthquake, the current research results mainly focus on mountain earth rock dam and low embankment in shallow sea. It is necessary to study the deformation and failure mode of reinforced subgrade with deep soft foundation under earthquake. Research conclusions:(1) Based on the finite element software Plaxis, the stability and deformation failure mode of reinforced subgrade with deep soft foundation reinforced soil under earthquake are studied by numerical simulation. The results show that under the current earthquake acceleration, the use of high strength geotextile will produce buoyancy effect and make the embankment slide as a whole.(2) Due to the buoyancy effect, the geotextile is not able to effectively exert its tensile strength, and the stability of embankment on soft foundation is mainly borne by the foundation soft soil with poor mechanical properties.(3) The research results can provide reference for the treatment of railway subgrade with deep soft foundation in high seismic intensity area.

关 键 词：地震 软土地基 加筋土路堤 变形破坏模式 数值模拟 

分 类 号：TU447[建筑科学—岩土工程]