渐进平移法在高速公路小半径曲线隧道中的应用

Application of Gradual Parallel Mobile in Small Radius Curved Tunnel of Expressway

潼南至荣昌高速公路采用时速100 km的双向四车道标准建设,因路线定测中对两座分离式隧道平曲线设置了+4%超高,需考虑隧道建筑限界布置和停车视距是否满足要求、隧道曲线外侧的单洞断面是否需要加大、隧道断面的工程经济性如何等。基于此,本文对小半径曲线隧道所遇上述问题进行逐项分析,运用渐进平移法解决了横坡超高Δh≤+3%和Δh=+4%的内轮廓大小相同而位置不同的二次衬砌过渡问题,从而有效运用隧道空间,满足隧道建筑限界的空间布置,最大限度改善了停车视距可用宽度。

The expressway from Tongnan to Rongchang adopts the standard construction of two-way four-lane at a speed of100 km/h.In the route measurement,the horizontal curves of two separate tunnels are set with a+4%high height.This puts forward the following requirements for the tunnel design:whether the layout of building limits and stopping sight distance in the tunnel contour meet the requirements;whether the single hole section outside the tunnel curve needs to be enlarged;how about the engineering economy of tunnel section.Therefore,this article analyzes the above problems of small radius curved tunnel item by item,and uses the method of gradual parallel mobile to solve the cross slope as ultra-highΔh≤+3%andΔh=+4%within the outline of the same size but different location of the secondary lining transition problems,thus the tunnel space is used effectively to meet the space arrangement of tunnel building boundary,and the available width of stopping sight distance is improved to the maximum.