【摘要】 考虑剪胀对隧道围岩稳定性的影响,对浅埋圆形盾构隧道、浅埋两车道公路隧道和浅埋双线铁路隧道在围岩发生塑性流动时进行力学特征分析。分析圆形盾构隧道围岩的位移,塑性区分布和最大剪切应变率;计算圆形断面、双线铁路隧道、双车道公路隧道等3种不同断面形状隧道的稳定性系数,分析剪胀角对围岩稳定性系数的影响。研究结果表明:剪胀角对围岩位移的影响存在一个临界值;在围岩发生塑性流动时,塑性区随着剪胀角的增大而逐渐增加;剪胀角对围岩剪切破坏带和围岩稳定性系数都有较大影响;随着剪胀角的变化,隧道临界稳定系数也发生变化。更多还原

【Abstract】 Considering the influence of shear dilation on the stability of surrounding rock,mechanical performance using finite differential code was conducted for circular shallow tunnels,two-lane highway shallow tunnels and double-track railway shallow tunnels when plastic flow occurred in the surrounding rock.Under the given conditions,the displacement,plastic zone and maximum shear strain rate of circular tunnel were emphatically simulated and analyzed.The stability factor of three tunnels was computed,and the influence of dilation angle on the stability factor was analyzed.The results show that there is a critical dilation angle which impacts the displacement of surrounding rock,that the plastic zone increases with the increase of the dilation angle,that the dilation angle has important effect on the shear bond and stability factors,and that the critical stability factors change along with the change of dilation angle when the shear dilation of surrounding rock is considered.更多还原