长江隧道大纵坡路面结构数值模型与分析

Numerical Analysis of Asphalt Pavement on Large Longitudinal Slope of Yangtze River Tunnel

长大跨江海隧道主体部分离地面较深,路面设计坡度高于一般隧道路面,由于隧道内行车视线差,出入隧道车辆将频繁的加、减速或刹车制动,这大大增加了大纵坡路面结构破坏的不利因素。本文的研究对象武汉长江隧道,匝道出入口路段坡度达到了4.35%-6.00%,隧道内的最大坡度也达到4%以上,形成了典型的大纵坡路面结构特点。文章结合现有路面结构组合层次和坡度条件,建立大纵坡路面结构三维有限元模型,分析在垂直荷载和水平荷载综合作用下的隧道大纵坡路面层间剪应力和沥青表面拉应力分布状况及规律,进行大纵坡路面结构受力性能研究,为武汉长江隧道和其他大型跨江海公路隧道大纵坡路面结构设计与施工提供参考。

Sea-River crossing tunnel is further away from the ground, its design gradient above the general one especially with the poor vision. The drivers have to frequently speed up or slacken up, or even jam on the brakes to adapt to the changed environment; all the negative factors will accelerate destruction of the road. In this paper, taken Wuhan Yangtze River Tunnel as study object, which longitudinal slope of the ramp entrance has reached 4.35%～6.00%, and the largest slope in tunnel is more than 4 percent too, that formed typical characteristics of pavement on large longitudinal slope. Combined the existing structural composition with gradient conditions, this article establishes a three-dimensional finite element model about pavement on large longitudinal slope of Wuhan Yangtze River Tunnel. To analyze the structural stress and displacement, the law of layer shear stress and the rule of tensile stress distribution on asphalt surface is summarized, when the comprehensive role of vertical load and level load be on it. All the results provide references in design and construction of large longitudinal slope pavement for Wuhan Yangtze River Tunnel and other large-scale Sea-River crossing tunnel.