侧部岩溶隧道围岩稳定性数值分析与研究

NUMERICAL ANALYSIS AND RESEARCH ON SURROUNDING ROCK STABILITY OF LATERAL KARST CAVE TUNNEL

结合忠垫高速公路岩溶隧道施工过程,利用有限差分软件FLAC3D对侧部含有溶洞的隧道围岩稳定性进行数值模拟研究,并将数值计算结果与现场监测结果进行比较分析。结果表明:隧道开挖后,围岩分别向溶洞内和隧道内变形,溶洞与隧道之间的围岩向2个相反的方向变形,是较危险区域。围岩塑性区主要集中在隧道的周围和溶洞的左右侧部,溶洞的顶部和底部处塑性区较少。隧道与溶洞之间的围岩由于应力集中可能使围岩产生过大的变形和岩体破坏,对其稳定性要给予特别重视。所得结论可为同类隧道的设计、施工和研究提供有益的借鉴和参考。

In combination with the construction process of karst cave tunnel of Zhongdian Highway,by using the finite difference software FLAC^3D,the surrounding rock stability of karst cave beside the tunnel is simulated,and the numerical calculation results and field monitoring results are compared.The results indicate that after the tunnel is excavated,the surrounding rock is converged toward the karst cave and the tunnel.The surrounding rock between the karst cave and the tunnel is converged in opposite direction and is also the more dangerous zone.The plastic zone of the surrounding rock mainly concentrates around the tunnel and the two sides of karst cave while the top and the bottom of karst cave have little plastic zone.The surrounding rock between tunnel and karst cave possibly brings large deformation and rock mass failure because of stress concentration,and its stability is focused seriously.The conclusion can be used for reference for the design,construction and research of similar tunnels.