考虑接缝影响的地下综合管廊振动台模型试验

Shaking table model test on seismic responses of utility tunnel with joint

地下综合管廊属于浅埋狭长型结构,变形缝存在较为普遍,而在地震荷载作用下,其会对地下结构的振动响应产生一定影响,但是目前针对该问题的研究却十分有限。基于振动台模型试验并考虑接缝的影响,开展了不同波形、不同峰值加速度地震波激励下的综合管廊地震响应特征研究,对场地加速度、动土压力以及管廊结构加速度、位移、动应变和弯矩等响应进行了测试和分析。试验结果表明:管廊振动主要受周边土体影响,接缝截面边墙在地震过程中与土体发生脱离,但管廊结构整体性保持良好;管廊接缝在强震下位移较小,不会发生大变形破坏;强震作用下动土压力分布呈非线性特征;接缝截面在地震中受到的弯矩作用小于中部截面,对抗震性能有利。

Deformation joints are universal in underground utility tunnels that belong to the shallow-buried and slender structure.Under seismic loads,the vibration response of the underground structure with a joint will be affected to a great extent.However,the studies on this problem are limited.In this paper,based on the shaking table model test that considers the influence of joints,the seismic response characteristics of the underground utility tunnel under seismic excitation with different waveforms and different peak accelerations were studied.The acceleration,soil pressure,displacement,strain,and bending moment were measured and analysed.The results indicated that the vibration of the tunnel was mainly affected by the surrounding soil and the sidewall of the joint section separated from soil during earthquake excitation,while the tunnel structure displayed a good integrity.The displacement of the tunnel joint was relatively small under the strong earthquake,which did not result in large-scale deformation failure.The distribution of seismic soil pressure under the strong earthquake was nonlinear.The moment on the joint section was less than that in the middle section in the earthquake,which was beneficial to seismic performance.