40 t无砟重载铁路隧底结构设计参数研究  

Study on design parameters of tunnel bottom structure of 40 t ballastless heavy haul railway

作　　者：苗德海[1] 王克金[1] 高建国[1] 余俊[2] 周涛[2] MIAO De-hai;WANG Ke-jin;GAO Jian-guo;YU Jun;ZHOU Tao(China Railway Siyuan Survey and Design Group Co.,LTD,Wuhan 430063,China;School of Civil Engineering,Central South University,Changsha 410075,China)

机构地区：[1]中铁第四勘察设计院集团有限公司,湖北武汉430063 [2]中南大学土木工程学院,湖南长沙410075

出　　处：《交通科学与工程》2020年第2期104-110,共7页Journal of Transport Science and Engineering

摘　　要：针对隧底围岩损伤的数值模拟,因采用理想状态下的弹塑性模型仅对强度参数进行折减,而循环荷载作用下围岩的累积损伤及隧底积水的反复冲刷作用均未考虑在内,使得计算结果与现场实测值相差较大的问题。本研究基于隧底围岩的累积损伤机理与隧底混凝土结构的损伤塑性特性,利用ABAQUS有限元软件建立隧道-围岩耦合二维计算模型,对重载列车荷载作用下,单线无砟隧道隧底衬砌结构的主要设计参数进行分析。研究结果表明:随着列车轴重的增加,隧道底部围岩逐渐出现损伤,当轴重为40 t时,隧底结构出现明显的损伤效果;改变矢跨比对仰拱竖向位移影响不大,当矢跨比大于1:7,仰拱结构拉应力增大趋势变缓;改变填充厚度对仰拱竖向位移影响不大,当填充层厚度大于1.1 m时,这种减小的趋势逐渐变缓。At present,the strength reduction method for the numerical simulation of tunnel surrounding rock damage only reduces the strength parameters using the ideal elastoplastic model.The cumulative damage of surrounding rock under cyclic loading and the water erode at the bottom of the tunnel is always ignored,so the calculation results are often quite different from the actual value.Based on the cumulative damage mechanism of tunnel surrounding rock and the damage plasticity of tunnel concrete structure,the large-scale finite element software ABAQUS was used to establish a two-dimensional model of tunnel surrounding rock.The main design parameters of lining structure of tunnel bottom were studied.The results show that the surrounding rock of the tunnel is damaged gradually with the increase of the axle weight of the train.Especially,the tunnel bottom structure is easily damaged by the 40 t axle load.The vertical displacement of the inverting arch is slightly impacted by the span ratio and the thickness of the filling layer.When the sagittal ratio reaches 1:7,the tensile stress of the invert arch structure increases slowly.When the thickness of the filling layer is greater than 1.1 m,the tendency of the reduction is gradually slowed down.

关 键 词：重载铁路 40 t轴重 隧底结构 动响应 关键参数 

分 类 号：U212.334[交通运输工程—道路与铁道工程]