多层交通荷载下非对称一体化地下结构的动力响应

Dynamic response of asymmetric integrated underground structures under multilayer traffic loads

地下结构在交通荷载作用下的动力响应对其运营期的安全稳定有重要影响。为了探究大断面非对称一体化地下结构在多层交通荷载作用下的动力响应特征,依据工程典型断面建立有限元模型,模拟施加路表、市政、轨道三层交通荷载,分析了非对称一体化地下结构的振动响应和应力分布特征,探究了多层交通荷载共同作用产生的结构动力响应叠加规律。结果表明:非对称一体化结构的振动响应在市政交通层的左幅顶板中部最大,达0.5~0.7 m/s^(2),动应力在轨道交通层底角处最大,达0.08~0.10 MPa;地铁列车荷载是结构动应力的主要影响源,但土钉支护与桩基支撑能够有效降低动应力的影响;作用于地面的车辆荷载会对一体化结构的振动响应产生较显著影响,运营期应重点关注位于地面车辆行驶密集路段的结构。研究结果可为地下非对称一体化结构的优化设计、运营期养护提供参考。

The dynamic response of underground structures under traffic loads has significant impact on their safety and stability during operation.In order to investigate the dynamic response characteristics of the asymmetric integrated underground structure with large cross-section under the action of multi-layer traffic loads,a finite element model was established based on a typical cross-section of a project,The application of traffic loads on road surface,municipal layer,and railway layer was simulated,the vibration response and stress distribution characteristics of the asymmetric integrated underground structures was analyzed,the superposition law of structural dynamic response generated by the joint action of multi-layer traffic loads was explored.Results show that the vibration response of the asymmetric integrated structure is the highest in the middle of the left top plate of the municipal transportation layer,reaching 0.5~0.7 m/s^(2),and the dynamic stress is the highest at the bottom corner of the rail transportation layer,reaching 0.08~0.10 MPa.The subway train load is the main source of the dynamic stress of the structure,but the soil nail support and pile foundation support can effectively reduce the effect of the dynamic stress.The vibration response of the integrated structure is significantly affected by the vehicle load on the ground.During the operation period,special attention should be paid to structures located in densely populated road sections with ground vehicles.The results can provide reference for optimization design and maintenance of underground asymmetric integrated structures during operation.