外水压力作用下深埋公路隧道衬砌受力特性与安全性研究

Study on Mechanical Characteristics and Safety of Deep-buried Highway Tunnel Lining under External Water Pressure

随着环保要求的日益提高,针对富水隧道工程提出了"以堵为主、限量排放"的治水理念,因此在设计时应充分考虑山岭富水地段隧道衬砌结构的抗水压能力。文章以春天门隧道为工程实例,采用"荷载-结构"模型对全断面承压情况下的抗水压衬砌结构进行了分析,得到了隧道抗水压衬砌结构的受力特征。结果表明,采用近圆形衬砌结构形式,能够较好地承受外水压荷载;衬砌结构全截面受压,拱脚小半径连接处隧道衬砌结构轴力和弯矩最大,相应的安全系数较小,为结构的最薄弱处。

With increase of requirements for environmental protection in recent years,the concept of "preferred blocking and limited drainage"has been put forward for the water-rich tunnels,and it's necessary to fully consider the capability of water pressure resistance of the lining structure of water-rich mountain tunnels.Based on the Chuntianmen tunnel,it analyzes the structure of water-resistant lining under bearing of full water pressure by a "loadstructure"model,and its mechanical characteristics were obtained.The results show that the quasi-round lining structure can bear the load of external water pressure very well;the safety factor is relatively small due to full-section of lining structure being under compression,and the maximum axial force and bending moment occur at the arch spring junction with small radius,so it's also the weakest point of the structure.