基于破坏接近度的机械化施工隧道安全步距研究  

Study on the safety step distance of mechanized construction tunnel based on failure approach index

作　　者：王毅 Wang Yi(Sichuan Transportation Construction Group Co.,Ltd.,Chengdu Sichuan 610000,China)

机构地区：[1]四川省交通建设集团有限责任公司,四川成都610000

出　　处：《山西建筑》2024年第17期164-168,共5页Shanxi Architecture

基　　金：四川交建集团企业课题:穿越富水沟谷浅埋段隧道施工关键技术研究(SCJJKY-2023-46)。

摘　　要：为了提升机械施工效率,探究机械化施工最大安全步距,以泸石高速得妥隧道为工程背景,采用有限元差分方案,结合破坏接近度理念,研究了步距对隧道围岩与结构稳定性影响。主要结论如下:随着安全步距的增大,隧道应力释放比例增大,沉降变形增大,但是幅度逐渐减小;安全步距的增大提高了初期支护的围岩压力分担比例,造成围岩拉压应力的提升,以拉应力提升为主。安全步距增大使围岩开挖损伤区范围增大,以仰拱端头至掌子面距离90 m为界,超过90 m围岩损伤区扩展显著,建议仰拱端头至掌子面距离不超过90 m。In order to improve the efficiency of mechanical construction and explore the maximum safety step of mechanized construction,this paper takes Detuo Tunnel of Lushi Expressway as the engineering background,adopts the finite element difference scheme,and combines the concept of failure approach index to study the influence of step distance on the stability of tunnel surrounding rock and structure.The main conclusions are as follows:With the increase of safety step,the proportion of tunnel stress release increases,and the settlement deformation increases,but the amplitude decreases gradually.The increase of the safety step distance increases the proportion of surrounding rock pressure sharing in the initial support,resulting in the increase of the tensile and compressive stress of the surrounding rock,mainly the tensile stress.The range of surrounding rock excavation damage zone increases with the increase of safety step distance.The damage zone of surrounding rock expands significantly when the distance between inverted arch end and tunnel face is more than 90 m.It is suggested that the distance between inverted arch end and tunnel face should not exceed 90 m.

关 键 词：隧道工程 机械化施工 安全步距 破坏接近度 

分 类 号：TU997[建筑科学—市政工程] U455[建筑科学—桥梁与隧道工程]