节理裂隙岩体中不同埋深无支护暗挖隧洞稳定性的离散元法数值分析

针对一高速公路隧道工程，应用离散单元法对节理裂隙岩体中不同埋深无支护暗挖隧洞的稳定性及其机理进行了数值分析。分析结果表明，当节理的赋存条件不利于隧洞稳定时，浅埋隧洞（如埋深只有5m）的稳定性不如埋深较大隧洞（如埋深50m）的稳定性好；反之，当节理的赋存条件有利于隧洞稳定时，则浅埋隧洞的稳定性比深埋隧洞的稳定性好。分析结果还表明，“压力拱”效应在浅埋隧洞节理裂隙围岩稳定性中起着重要作用。

DEM ANALYSIS ON STABILITY OF UNSUPPORTED TUNNELS IN JOINTED ROCK MASSES AT DIFFERENT DEPTHS

The stability of unsupported tunnels in jointed rock masses at different depths is analyzed using the distinct element method. The analysis of an autobahn tunnel shows that the unsupported shallow tunnels (for example,at a 5 m depth) are not as stable as those at a larger depth (for example,at 50 m) if the joints are steep and there exist more joint sets,and vice versa. The pressure-arch effect on the stability of jointed rock mass surrounding a shallow tunnel proves to be important.