为分析新建公路隧道近接上跨施工对既有隧道的影响，依托重庆红岩村大断面公路隧道0.33 m小净距上跨既有轨道环线隧道工程建立三维有限元模型，通过计算分析得到轨道环线隧道二次衬砌应力、变形的分布与变化规律。结果表明： 红岩村隧道台阶法施工时，上、中台阶开挖对轨道环线隧道影响最大，而下台阶开挖影响较小；轨道环线隧道二次衬砌以竖直向上变形为主，极值位于红岩村隧道正下方4个交叉断面处，且在4个断面附近，轨道环线隧道二次衬砌环向拉应力较大，存在拉裂的可能。轨道环线的受力变形情况依据红岩村隧道开挖过程可划分为3个阶段，并由此得到红岩村隧道开挖核心控制区长度约58 m，以此划分施工控制范围并采用秒雷管控制爆破及机械开挖等不同的施工方案，实现红岩村隧道的顺利上跨施工。

In order to analyze the influence of adjacent overcrossing construction of a newlybuilt tunnel on existing tunnel, a 3D FEM model is established to simulate the large crosssection Hongyancun Highway Tunnel (HHT) crossing above the existing Rail Transit Loop Line Tunnel (RTLLT) in Chongqing with the minimum vertical clear spacing of 0.33 m. And the distribution and variation laws of stress and deformation of the secondary lining of RTLLT are obtained and analyzed. The results show that: (1) When the bench method is used for HHT, the influence of excavation of top heading and middle bench on the RTLLT is the largest, while that of the excavation of lower bench is the smallest. (2) The deformation of RTLLT is characterized by vertical deformation, and the maximum values locate at the four crossing sections of the RTLLT right below the HTT, where cracks might appear in the secondary linings due to the large tensile stress. In addition, the stress and deformation variation of RTLLT can be divided into three stages with the excavation of HHT, and the 58meterlong core excavation control region for HHT can be determined. Accordingly, the construction control area is divided and different construction methods such as controlled blasting with second delay detonators and mechanical excavation are used to ensure the successful overcrossing construction of HTT.