小断面水工隧道成洞质量影响的数值研究

Numerical Study on the Effect of Small Cross-section Hydraulic Tunnel on the Quality of the Cavity

近年来,随着隧道的大量建设,在建隧道坍塌事故频发,尤其在围岩岩性较差地段。因此,基于某实例水工隧道施工过程,采用有限元分析方法建立隧道数值模型,研究分析在不同的强弱参数条件下,扰动层围岩和隧道衬砌的沉降变形位移和有效应力变化特征。结果表明:随着扰动层的围岩强度参数增加,扰动层的隆起值不断减小;反之,隧道围岩的扰动层强度参数减小后,隧道围岩位移沉降值不断增大;随着隧道围岩扰动层强度参数的增大,围岩和隧道衬砌结构的有效应力不断减小;反之,隧道围岩强度参数弱化使围岩和隧道衬砌的有效应力增大并出现应力集中现象。结果可为类似施工工程提供指导,具有一定的工程意义。

In recent years,with the large-scale construction of tunnels,tunnel collapse accidents frequently occur,especially in areas with poor surrounding rock lithology.Therefore,based on the construction process of an example hydraulic tunnel,the finite element analysis method is used to establish the numerical model of the tunnel,and the characteristics of the settlement,deformation,displacement and effective stress of the surrounding rock and tunnel lining of the disturbed layer under different strong and weak parameters are studied and analyzed.The results show that with the increase of the surrounding rock strength parameters of the disturbed layer,the uplift value of the disturbed layer decreases continuously.On the contrary,when the strength parameter of the disturbed layer of the surrounding rock of the tunnel decreases,the displacement and settlement value of the surrounding rock of the tunnel increases continuously.With the increase of the strength parameters of the disturbed layer of the surrounding rock,the effective stress of the surrounding rock and the tunnel lining structure decreases continuously.On the contrary,the weakening of the tunnel surrounding rock strength parameters increases the effective stress of the surrounding rock and the tunnel lining and causes stress concentration.The results can provide guidance for similar construction projects and have certain engineering significance.