曲率半径对小净距超大断面隧道地震响应的影响

为揭示不同曲率半径对小净距超大断面隧道地震响应特征的影响，以长乐龙门隧道为研究对象，分别建立曲率半径为400、 600、 800、 1 000和∞m的模型.结果表明，在横向和纵向地震的作用下，曲率对小净距超大断面隧道地震响应有较大影响.受曲率半径的影响，隧道左右洞凸侧(右侧)的内力均大于凹侧(左侧),且随着曲率半径的减小，右侧内力与左侧内力的差距增大.此外，曲线隧道拱顶和仰拱处的弯矩、剪力均随着曲率半径的减小而增大，而拱脚处的弯矩、剪力、轴力则均随着曲率半径的减小而减小.位移受曲率半径影响较小，变化幅度不超过1%.因此，隧道抗震设计时应考虑隧道曲率半径的影响.

Influence of curvature radius on seismic response of tunnels with small clear distance and super large cross-section

In order to reveal the influence of different curvature radii on the seismic response characteristics of the tunnel with small clear distance and large cross-section, the Changlelongmen Tunnel was taken as the research object to establish linear models with radii of 400m, 600m, 800m and 1000m, respectively. The results show that the curvature has a great influence on the seismic response of the tunnel with small clear distance and large section under transverse and longitudinal earthquakes. The internal forces on the convex side (right side) of the tunnel are greater than those on the concave side (left side) under the influence of the curvature radius, and the gap between the internal forces on the convex side and the concave side is greater with the reduction of the curvature radius. In addition, the bending moment and shear force at the arch and inverted arch increase with the decrease of the curvature radius, while the bending moment, shear force and axial force at the arch foot decrease with the decrease of the curvature radius. The displacement is less affected by the radius of curvature, and the variation range is less than 1%. Therefore, the influence of tunnel curvature radius should be considered in seismic design.