公路隧道沥青路面结构的力学性能研究

Research on Mechanical Properties of Asphalt Pavement in Highway Tunnel

应用三维有限元方法,对双轮垂直荷载和由于车辆加减速引起的水平荷载共同作用下沥青层应力响应进行分析,并对不同双轮重、不同沥青层和基层的模量厚度以及各结构层间不同接触状态下沥青层应力曲线响应进行了探讨分析。结果表明,荷载轮底下沥青层内部基本处于受压状态,荷载轮隙中间表面存在较大的拉应力,并在荷载接触面边缘有较大的剪应力。确定出合理的沥青层厚度为14 cm,加强结构层之间的粘结可以有效地控制沥青层底面的裂缝。根据不同的基岩强度设置相应的基层类型和基层厚度以及改善沥青混凝土质量也是公路隧道沥青路面结构设计时应考虑的问题。

A linear full three-dimensional finite element method was performed to present the key design parameters of highway tunnel asphalt pavement under double-wheel load on rectangular loaded area considering horizontal contact stress induced by the acceleration/deceleration of vehicles. The influencing factors such as double-wheel weight, asphalt layer thickness, base course stiffness modulus and thickness, and the contact conditions among the structure layers on these key design parameters were also examined separately to propose construction procedures of highway tunnel asphalt pavement. The result show that （1） the interior of asphalt layer directly under the load is compressed; （2） there exist large horizontal tensile stresses at the tyre interval surface and large shear stresses acting in the contact area edge.The desirable asphalt layer thickness is 14 cm. Strengthening the bond among structure layers can effectively control cracking at the bottom of the asphalt layer. Setting corresponding base type and thickness according to different rock modulus and refining the quality of asphalt concrete should be considered in the design of asphalt pavement in highway tunnel.