浅埋暗挖地铁车站衬砌结构应力分析

Analysis of Lining Structure Stress of Shallow-Buried and Hidden Excavated Metro Tunnel

浅埋暗挖地铁车站施工期衬砌结构的安全性对施工安全有着重要的影响。本文采用数值模拟方法,对大连地铁某中洞法施工的车站初衬和二次衬砌的应力状态进行了分析,依据数值模拟的结果对它们是否满足承载要求进行了研究。研究表明:车站拱顶初衬受压区混凝土强度接近极限强度,须配置合适的钢筋才能满足承载要求。拱顶初衬受拉区配筋后也能满足要求。拱顶二衬能满足支护承载力要求。最大弯矩处的初衬配筋为超筋,该设计需要进行优化。结构底板的内力状态为弯矩较大,而轴力较小,底板能满足承载要求。文中的应力分析方法也可以作为类似暗挖隧道的衬砌结构安全性评价的参考。

Safety of linings of shallow-buried and hidden excavated metro tunnel under the construction has the important effect on the safety of engineering construction.Authors analyse the stress state of initial linnings and secondary linings in one station of Dalian metro which in central-drift construction method by using numerical simulation.Judge whether they satisfy bearing requirements or not by the numerical simulation results.The results show that the concrete strength of initial linings which are in pressure area of vaults are near ultimate strength.So they should be configurated enough steels to satisfy bearing requirements.The initial linings which are in tensile areas of vaults can satisfy bearing requirements.The secondary linings which are in tensile areas of vaults can satisfy bearing requirements.The initial linings which are maximal bending moment areas are overreinforced.So the design should be optimizated.There are bigger bending moment and smaller axial forces in bottom plates.The bottom plates can satisfy bearing requirements.Stress analysis method in this paper provides a good model for safety of linings judgement in other similar engineerings.