填方高度对明洞衬砌运营安全的影响研究  

Research on the Influence of Fill Height on the Operation Safety of Open-cut Tunnel Lining

作　　者：余大龙[1] 舒东利[1] 廖余[1] 华阳 YU Dalong;SHU Dongli;LIAO Yu;HUA Yang(China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu,Sichuan 610031,China)

机构地区：[1]中铁二院工程集团有限责任公司,四川成都610031

出　　处：《施工技术（中英文）》2022年第10期50-53,共4页Construction Technology

基　　金：四川省科技计划项目(2019YFG0460);中铁二院工程集团有限责任公司科技开发课题(KYY2019046(19-21))。

摘　　要：为解决高填方明洞衬砌开裂后运营安全性问题,以广通—大理铁路云驿高填方明洞工程为依托,采用理论分析与工程实践相结合的方法,对高填方明洞开裂后原填土高度和清方减载方案衬砌安全性进行计算分析。通过对裂缝进行观测,D1K122+730—D1K123+020段隧道拱顶中心线两侧2.5m范围内,裂缝呈线性分布;采取清方减载后,裂缝最大宽度仅发展0.01mm,其余位置裂缝宽度和深度均没有继续发展。通过数值模拟计算,在原设计填方高度15m的回填土石压力及结构自重作用下,明洞衬砌最小安全系数为3.66;明洞上方回填土石高度降低至5m后,明洞衬砌最小安全系数为10.93,衬砌所受荷载减小。结合现场观测和数值计算,发现二者得到的裂缝发展规律一致,对明洞衬砌上方填土进行清方减载有利于结构安全。In order to solve the problem of operation safety after cracking of high fill open-cut tunnel lining,Yunyi high fill open-cut tunnel of Guangtong to Dali Railway are taken as the engineering background example.Combining theory analysis with engineering practice,the lining safety of original fill height and the clearing and load reduction scheme after the cracking of the high fill open-cut tunnel are calculated and analyzed.Through the observation of cracks,the cracks are distributed linearly within 2.5 m on both sides of the center line of the tunnel vault in D1 K122+730—D1 K123+020,and adopting clearing and load reduction scheme,the maximum crack width only increased by 0.01 mm,and the crack width and depth did not continue to develop in other positions.Through numerical simulation calculation,under the action of the backfill soil and rock pressure with the original design filling height of 15 m and the self-weight of the structure,the minimum safety factor of the open-cut tunnel lining is 3.66.After the height of the backfill soil and rock above the open-cut tunnel is reduced to 5 m,the minimum safety factor of the open-cut tunnel lining is 10.93,and the load on the lining is reduced.Combined with field observation and numerical calculation,it is found that the crack development law obtained by the two is consistent,and the clearing and load reduction of the fill above the open-cut tunnel lining is beneficial to the structural safety.

关 键 词：隧道工程 高填方 明洞 开裂 安全性 

分 类 号：U455[建筑科学—桥梁与隧道工程] U459.1[交通运输工程—道路与铁道工程]