甘青隧道初始地应力场分析及岩爆预测  

Analysis of initial ground stress field and prediction of rockurst in Ganqing Tunnel

作　　者：李启弟 梁庆国[1] 周仁 杨家伟 蔡遵乐 LI Qidi;LIANG Qingguo;ZHOU Ren;YANG Jiawei;CAI Zunle(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,Gansu,China;China Railway No.2 Engineering Group Co.,Ltd.,Chengdu 610031,Sichuan,China)

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070 [2]中铁二局集团有限公司,四川成都610031

出　　处：《隧道与地下工程灾害防治》2024年第4期50-60,共11页Hazard Control in Tunnelling and Underground Engineering

基　　金：国家自然科学基金资助项目(51968041);中国博士后科学基金资助项目(2021M693843);兰州交通大学“百名青年优秀人才培养计划”资助项目(2017150)

摘　　要：为探明西成铁路甘青隧道工程区初始地应力场分布规律并准确预测岩爆,采用多元线性回归原理,基于隧道工程区实测地应力数据、地形地貌、地层岩性、地质构造和试验研究成果等,利用FLAC3D数值模拟分析软件进行反演分析工程区初始地应力场。分析隧道开挖卸荷后的应力重分布和局部应力集中情况,并结合修正的“谷-陶岩爆判据”对隧道高地应力区段可能发生岩爆的具体部位及其强度进行预测。研究结果表明:甘青隧道处于地质构造复杂、应力高度集中以及大埋深的高地应力环境,燕山期闪长岩和三叠系板岩岩体坚硬、完整性良好,存在岩爆风险;甘青隧道工程区最大主应力为2.3~25.2 MPa,最小主应力为1.0~15.8 MPa,三向主应力在埋深小于300 m时关系为SH>Sh>SV(SH为大主应力,Sh为小主应力,SV为垂直主应力),在埋深为300~700 m时关系为SH>SV>Sh,且地应力特征以水平构造应力为主;甘青隧道整体呈现弱-中等岩爆状态,甘青隧道DK394+700—DK398+500具备发生高岩爆活动的条件,DK384+500—DK394+700、DK398+500—402+200具备发生中等岩爆活动的条件。In order to explore the distribution law of the initial ground stress field in the Ganqing Tunnel engineering ar⁃ea of Xicheng Railway and accurately predict the rockburst,the principle of multiple linear regression was adopted.Based on the measured stress data,landform,stratum&lithology,geologic structure and experimental research results,etc.,the FLAC3D numerical simulation analysis software was used to invert and analyze the initial stress field of the pro⁃ject area.The research analyzed the stress redistribution and local stress concentration after unloading during tunnel exca⁃vation,and predicted the specific location and strength of rock burst that may occur in the high stress section of the tun⁃nel based on the modified"Gu⁃Tao rockburst criterion".The research results indicated that the Ganqing Tunnel is loca⁃ted in a high stress environment with complex geological structures,high stress concentration,and large burial depth.The Yanshanian diorite and Triassic slate rock masses were hard and intact,and there is a risk of rockburst;The maxi⁃mum principal stress in the Ganqing Tunnel project area was 2.3⁃25.2 MPa,and the minimum principal stress was 1.0⁃15.8 MPa.The relationship between the triaxial principal stress was SH>Sh>SV when the burial depth was less than 300 m,and SH>SV>Sh when the burial depth was 300⁃700 m.The stress characteristics were mainly horizontal structural stress;The Ganqing Tunnel as a whole presented a weak to moderate rockburst state.The Ganqing Tunnel DK394+700—DK398+500 had the conditions for high rockburst activity,while DK384+500—DK394+700 and DK398+500—402+200 had the conditions for moderate rockburst activity.

关 键 词：铁路隧道 初始地应力场 地应力场反演 岩爆预测 数值模拟 

分 类 号：U45[建筑科学—桥梁与隧道工程]