Due to the particularity of surrounding rock properties and stress environment of squee-zing surrounding rock tunnel,the characteristic curve of surrounding rock is obviously different from that of conventional tunnel.In order to study the interaction relationship between surrounding rock and support in squeezing surrounding rock tunnel,the characteristic curve of surrounding rock was modified by considering the support effect.The influence of different deformation grades on the modified charac-teristic curve of surrounding rock was studied,and the primary support of double-track railway tunnel with squeezing surrounding rock was optimized.The results show that the arch foot and the wall foot are safe control positions due to the influence of stress concentration under the condition of a rough tun-nel.With the increase of deformation grade and lateral pressure coefficient,the support characteristic curve and the modified surrounding rock characteristic curve no longer intersect.The deformation of grade Ⅰ and grade Ⅱ can meet the safety requirements by using single-layer support.The anchors only need to be arranged in the arch and side wall positions,and the deformation anchors of grade Ⅱ and above need to be arranged in the whole ring.Grade Ⅳ deformation needs to consider measures such as improving the shape of the tunnel and advanced reinforcement while adopting double-layer support.
关键词
挤压性围岩隧道/变形等级/应力释放法/修正围岩特征曲线/支护特征曲线
Key words
squeezing surrounding rock tunnel/deformation grade/stress release method/modified surrounding rock characteristic curve/supporting characteristic curve
维普
万方数据