公路隧道出入口平面线形一致性检验研究

由于地形、地物等条件的限制，项目选线中隧道洞口段位于回旋曲线上，考虑到洞口段行车的安全，规范对隧道出入口的平面线形一致性有专门的要求，但在实际操作过程中存在一定的困难和分歧。以JTG D20--2006公路路线设计规范中不设缓和曲线的圆曲线最小半径以及回旋曲线最小长度计算出的临界内移值P，提出了一个隧道出入口平面线形一致性检验的定量化判据，即行车道中心线上距洞口3s设计速度行程终点与驾驶员继续按设计时速行驶3s后的位置偏差△D≤临界内移值P，否则就认为不满足一致性要求。

Study on Planimetric Alignment Consistency of Portal Sections of Highway Tunnels

Limited by the topography, planimetric features and other conditions, it is common that the portal sections of tunnels are located on swing curves. For the safety of the driving, in relevant specifications there are special requirements on the planimetrie alignment consistency of the portal sections of tunnels. However, it is difficult to fulfill these requirements. In this paper, a quantitative criteria to check the planimetric alignment consistency of the portal sections of tunnels is proposed on basis of the critical inside movement value ＂p＂, which is calculated according to the minimum radius of the circular curve without the transition curve and the minimum length of the swing curve specified in Design Specification for Highway Alignment （JTG D20--2006）. The quantitative criteria proposed is as follows： the deviation between the end point of 3s driving at the design speed from the tunnel portal and the position reached by the driver following 3s driving at the design speed should be less than the critical inside movement value ＂p＂ , otherwise, it is considered that the consistency requirements have not been met.