特长深埋隧道岩爆倾向性预测与影响因素研究  

Prediction of Rockburst Tendency and Study of Influencing Factors in Extra-Long Deep-Buried Tunnels

作　　者：陈贤丰 李德武[2] 刘金松[1] CHEN Xianfeng;LI Dewu;LIU Jinsong(China Railway Eryuan Engineering Group Co.Ltd.,Chengdu 610031,China;School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,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 [2]兰州交通大学土木工程学院,甘肃兰州730070

出　　处：《防灾减灾工程学报》2024年第5期1184-1192,共9页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金项目(51868038);中国铁路兰州局集团有限公司科技研究开发计划(2020-41)资助。

摘　　要：岩爆倾向性预测是深埋硬岩隧道工程施工的难点,以往研究多以隧道施工中现场监测数据为预测基础,但预测结果存在时效性和局限性。从西南地区某特长深埋隧道工程区地应力现场实测数据出发,对区域地应力场进行三维数值反演分析,获取隧道轴向地应力特征,从而对隧道施工中岩爆倾向性等级进行预测,并利用数值模拟手段对岩爆影响因素进行对比分析,其结果可为类似特长深埋隧道工程提供参考。研究结果表明:①实测点附近三向主应力总体趋势为:σ_(H)>σ_(v)>σ_(h),其中最大水平主应力σ_(H)值为10.96~17.07 MPa,方向N9°W~N7°E;②隧道轴向最大水平主应力σ_(H)最大值为23.88 MPa,最小水平主应力σ_(h)较恒定;竖向主应力σ_(v)最大值为46.70 MPa,其量值变化和隧道埋深呈正相关。该隧道具备岩爆发生的基本条件,施工中存在中等、强烈岩爆风险;③侧压系数为0.8时,墙角处岩爆倾向性较大,其他各部位倾向性相同;埋深越大,岩爆倾向性越大,且各部位岩爆倾向性受埋深的影响程度基本一致;围岩弹性模量为40 GPa时,岩爆倾向性最大;围岩内摩擦角大于40°时,隧道断面各部位岩爆倾向性趋于平稳。Rockburst tendency prediction is a challenge in the construction of deep-buried hard rock tunnels.Previous studies have mainly relied on on-site monitoring data from tunnel construction,but these predictions are limited by their timeliness and scope.Based on the field-measured data of geostress from an extra-long deep-buried tunnel engineering area in Southwest China,a three-dimensional numerical inversion analysis of the regional stress field was conducted to obtain the axial stress characteristics of the tunnel.This enabled the prediction of rockburst tendency levels during tunnel construction.Numerical simulation methods were used to compare and analyze the influencing factors of rockburst.The results can serve as a reference for similar extra-long deep-buried tunnel projects.The research results showed that:(1)The overall trend of the three-direction principal stress near the measurement point wasσ_(H)>σ_(v)>σ_(h),with the maximum horizontal principal stressσH ranging from 10.96~17.07 MPa,oriented at N9°W~N7°E.(2)The maximum horizontal principal stressσH in the tunnel was 23.88 MPa,while the minimum horizontal principal stressσh was relatively constant.The vertical principal stressσv reached 46.70 MPa,and its variation was positively correlated with the tunnel's burial depth.The tunnel met the basic conditions for rockburst occurrence,with moderate to strong rockburst risk during construction.(3)When the lateral pressure coefficient was 0.8,the rockburst tendency was higher at the wall corners,while other locations exhibited similar tendencies.The greater the burial depth,the higher the rockburst tendency,and the impact of burial depth on rockburst tendency was generally consistent across different locations.When the elastic modulus of the surrounding rock was 40 GPa,the rockburst tendency was the largest.When the internal friction angle of the surrounding rock exceeded 40°,the rockburst tendency across the tunnel section became stable.

关 键 词：深埋隧道 岩爆预测 地应力场反演 影响因素 

分 类 号：TU456.3[建筑科学—岩土工程]