地铁振动荷载作用下的地裂缝场地土体振动规律研究

发布时间：2018-02-06 06:43

本文关键词： 地裂缝动力响应列车荷载振动响应　出处：《长安大学》2017年硕士论文　论文类型：学位论文

【摘要】：作为“一带一路”的桥头堡—西安正在大力发展地铁轨道交通事业,为实现经济跨越式发展打下坚实基础。但是,西安地铁在建设过程中,遇到了穿越地裂缝这一难题,由于这一问题在此前从未遇到,因此,如何保证穿越地裂缝带地铁行车安全,以及减轻地铁穿越地裂缝时振动荷载对周边人居环境的影响,成为西安地铁建设中必须正视的重要课题。本文依托国家自然科学基金项目“地铁动荷载作用下的地层—地裂缝—隧道相互作用研究”,以穿越地裂缝的西安地铁2号线工程为背景,建立大型缩尺动力物理模型试验,结合数值模拟方法开展了地铁振动荷载作用下的地裂缝场地土体振动研究,主要的研究成果如下:(1)开展了有、无地裂缝时的隧道—围岩动力相互作用模型试验,并对两种工况下的试验结果进行了对比分析,从时域、频域和振级评价等多角度分析土体的振动响应,得到了振动传播和衰减规律,揭示了地裂缝对振动传播的阻碍效应;同时也分析了不同列车车速、不同列车激振频率下的围岩振动特性。(2)建立完整的“列车—隧道—围岩—地裂缝”三维有限元模型,采用“平台移动法”施加列车荷载,分析了列车高速行驶状态下的地裂缝场区围岩动力响应特性,研究了地裂缝带两侧土体的振动响应的突变效应。(3)参考地铁地表振动预测的相关文献资料,结合西安地铁工程实际情况,确定了影响西安地铁振动预测的五项振动修正因子,推导了西安地铁地表振动预测公式,并对跨地裂缝带地铁设计提出了防振减振措施建议。
[Abstract]:As a "Belt and Road" bridgehead-Xi'an is vigorously developing subway rail transit, for the realization of economic leaps and bounds to lay a solid foundation. However, Xi'an subway in the process of construction. Has encountered this difficult problem through the ground crack, because this problem has never encountered before, therefore, how to ensure the subway traffic safety through the ground crack belt. And to reduce the impact of vibration load on the surrounding human settlements when the subway passes through the ground fissure. Xi'an subway construction must face up to the important subject. This paper relies on the National Natural Science Foundation project "Strata-ground fissure-tunnel interaction study under the dynamic load of subway". Based on the project of Xi'an Metro Line 2 through ground fissures, a large scale dynamic physical model test was established, and the soil vibration of ground fissures was studied by numerical simulation method. The main research results are as follows: (1) the model test of tunnel-surrounding rock dynamic interaction without ground fissure is carried out, and the experimental results under two conditions are compared and analyzed from time domain. The vibration response of soil is analyzed from frequency domain and vibration level evaluation, and the laws of vibration propagation and attenuation are obtained, and the hindrance effect of ground crack on vibration propagation is revealed. At the same time, the vibration characteristics of surrounding rock under different train speed and different train exciting frequency are analyzed. 2) A complete three-dimensional finite element model of "Train-tunnel-surrounding rock fissure" is established. In this paper, the dynamic response of surrounding rock in the ground fissure field is analyzed by means of "platform moving method", which is applied to train load at high speed. The catastrophe effect of the vibration response of soil on both sides of the ground fissure zone is studied. (3) referring to the relevant literature data of the ground vibration prediction of the subway, combined with the actual situation of Xi'an subway project. Five vibration correction factors affecting the vibration prediction of Xi'an subway are determined, the prediction formula of surface vibration of Xi'an subway is deduced, and the measures to prevent vibration and reduce vibration are put forward for the subway design of cross-ground crack zone.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U211.3;TU435

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