炭质板岩地层公路隧道结构受力特征及优化

Pressure Characteristics and Optimization of Highway Tunnel Structure in Carbonaceous Slate Stratum

在炭质板岩地层中进行隧道施工会面临软弱围岩大变形、掌子面易失稳等问题,合理的支护结构体系是隧道施工安全和经济的保障。为此,依托峨汉高速豹狸岗隧道工程,通过对Ⅳ级围岩段隧道施工过程中围岩压力、围岩-结构间接触压力、支护结构内力等进行监测分析,获得Ⅳ级围岩形变荷载分布规律及结构受力特征,研究表明:初期支护和二次衬砌的安全度较高,但支护材料强度没有得到充分发挥。因此基于支护结构受力有限元分析,对二次衬砌的支护参数进行优化,提出的支护优化方案整体可行,可为类似的工程提供一定的参考价值。

Tunnel construction in carbonaceous slate always confronts such problems as large deformation of soft surrounding rocks and easy instability of the tunnel face.Reasonable support structure system provides a guarantee for the safety and cost in tunnel construction.For this reason,monitoring,measurement,and analysis were conducted on the surrounding rock pressure,the contact pressure between the surrounding rock and the support structure,and the internal force in the support structure during the tunnel construction process in Grade IV of Baoligang Tunnel Project on E-Han highway.And thus the deformation load and structure pressure on the surrounding rocks in Grade IV were determined and recorded.The analysis shows that in terms of safety,the primary support and secondary lining can strongly meet the requirements,but the strength of the supporting materials is not fully utilized.Based on the finite element analysis of the support structure,this article optimizes the support parameters of the secondary lining.The proposed support optimization scheme is feasible on the whole and referentially valuable to other similar civil engineering projects.