大直径公路隧道横通道设置与否以及如何设置问题一直存在较大争议，而横通道结构的力学行为规律研究对评估和控制其设置风险具有重要意义。为深入探究横通道变形缝在不均匀变形和抗震性能影响下的力学行为规律，确定其最佳设置位置，以钱江隧道工程的设计方案为基础计算模型，基于钱江隧道工程地质环境特点，提出4种相对变形模式，建立钱江场地人工波，分别从不均匀变形和抗震性2个角度，建立有限元分析模型，研究不同变形缝设置工况下主隧道及横通道的力学行为规律，进而寻找变形缝最佳设置位置，并确定其容许差异变形量。通过研究分析得出，综合考虑不均匀变形和抗震性的影响，钱江隧道横通道变形缝的最佳设置位置为距离相邻主隧道边缘1.2 m处，变形缝容许差异变形不宜小于6 cm。

There has been a great controversy over the setting of the cross passage in a large diameter highway tunnel and how to set up, while the mechanical behavior of the cross passage structure is of great significance for evaluating and controlling its risk. In order to explore the mechanical behavior of cross passage deformation joint under the influence of uneven deformation and seismic performance and determine the best setting position, the design scheme of Qianjiang River Tunnel project is taken as a basic calculation model for the analysis. Based on the characteristics of Qianjiang River Tunnel engineering geological environment, four relative deformation models are proposed; artificial site seismic wave of Qianjiang River are established; finite element analysis model is built to study the mechanical behavior of the tunnel and the cross passage respectively from two aspects of inhomogeneous deformation and aseismatic performance. Based on analysis, the optimal setting location and allowable deformation of cross passage deformation joint are determined. It is concluded that integrated taking into account the effects of inhomogeneous deformation and aseismatic behavior, the optimal setting location of deformation joint of cross passage of Qianjiang River Tunnel is 1.2 m away from the edges of tunnel; and the optimal allowable deformation is greater than or equal to 6 cm.