热力耦合作用下拉林铁路桑珠岭隧道岩爆预测

热力耦合作用是高温高地应力隧道岩爆预测中一个新的问题.在新建拉林铁路桑珠岭隧道开挖过程中，利用现场温度测试数据反演并得到隧道不同埋深时的地温，通过热力耦合数值模拟计算得到隧道开挖过程中的洞周应力变化规律，利用卢森、陶振宇、王元汉、樊建平4种岩爆判据对隧道不同温区、不同洞周应力释放率的岩爆发生烈度和岩爆范围进行预测，最后将预测结果与现场岩爆进行了比较分析.研究结果表明:桑珠岭隧道地温梯度为5.5℃/100 m，隧道埋深越大地温越高；在以自重应力场为主的深埋段，最大压应力集中在拱顶和拱脚部位；在45~85℃地温区间，洞周最大切向应力和最大主应力随应力释放率增大而线性增长，当洞周应力释放率为100%时，其增加量分别为84~96 MPa、93~96 MPa，同时岩爆烈度等级也相应增加；判据预测与现场实测的比对表明，高温热力耦合作用在应力释放过程中加速了岩爆发生，在应力释放率前期，陶振宇判据对中等及以上岩爆的发生更加敏感，而在应力释放中后期王元汉判据与实测结果的相似度更为一致. 

Prediction of Rock Bursts for Sangzhuling Tunnel Located on Lhasa-Nyingchi Railway Under Coupled Thermo-Mechanical Effects

Coupled thermo-mechanical effects on the prediction of rock bursts for tunnels with special geostress and high geotemperatures is a new problem that needs to be solved. During the excavation of the newly built Sangzhuling tunnel in the Lhasa-Nyingchi railway project, the geotemperature at different buried depths was obtained by field temperature test data inversion. The gradually changing hole stress during the excavation process was clarified by coupled thermo-mechanical numerical simulation. The range and intensity of rock bursts throughout the entire calculation scope of a typical section under various stress-relieving coefficients and geotemperature conditions, combined with different of rock burst criteria, such as Russense, TAO Zhenyu, WANG Yuanhan, and FAN Jianping criteria, were predicted. Finally, the prediction results were compared with the field measurements. The results show that the geothermal gradient of Sangzhuling tunnel is 5.5℃/100 m. As the buried depth of the tunnel increases, so does the geotemperature. The maximum compressive stress is concentrated in the vault and the arch springing in the deep-buried tunnel section with the gravity stress field. At 45-85℃, the maximum tangential and principal stresses increase linearly with an increase in the stress-relieving coefficient, and the maximum tangential and principal stresses increase by 84-96 MPa and 93-96 MPa, respectively, when the stress-relieving coefficient reaches 100%; the intensity of rock bursts will increase under these conditions. The analysis using the four methods for predicting rock bursts compared with rock burst data from results in field tests shows that the occurrence of rock bursts will be accelerated during stress release by coupled thermo-mechanical effects. The prediction of middle level and greater intensity rock bursts using the TAO Zhenyu criterion shows great sensitivity for the earlier stages of stress release. In the mid-late periods of stress release, the rock bursts prediction results using the WANG Yuanhan criterion are in accordance with the measured results.