Reliability Analysis and Evaluation of the Design of Bifurcation Tunnel Diverting and Merging Areas

With the increasing demand for road construction and limited land use on the ground, the bifurcation tunnel interchange project will become a common engineering form for future tight road networks. The safety of the branching and merging areas in tunnels should be given attention due to the influence of tunnel structures. By analyzing the driving characteristics of vehicles in the branching tunnel merging area, based on the visual distance requirements and vehicle driving characteristics of the merging area, the merging area and design reliability requirements of the branching tunnel were proposed. A reliability judgment model for the splitting impact based on the secondary deceleration theory was constructed, and reliability judgment standards for the length design of parallel deceleration lanes and direct deceleration lanes in the branching tunnel were proposed. This provides some reference and guidance for the design engineering practice and research of the branching tunnel merging area in the future.