【摘要】 研究目的:地铁车辆动荷载的长期作用会使隧道产生不同程度的沉降,对其运营稳定性产生不利的影响,对于饱和软土地层条件,隧道的沉降更为明显。开展动荷载作用下地铁隧道下卧土体的动力稳定性研究,有助于正确认识地铁运营荷载对周围土体的影响,并为隧道周围土体的加固提供依据。研究结论:通过分析盾构隧道的运营受力特征,设计了物理模拟试验系统,对地铁盾构隧道下卧粉质黏土的动力特性进行了研究,分析了不同荷载幅值、不同频率条件下隧道下卧粉质黏土的动力响应特性,并对动荷载作用下隧道的沉降特征进行了分析。试验结果表明,盾构隧道下卧粉质黏土在动荷载的作用下,土体的动力响应随距离的增加而衰减,且距离隧道越近衰减趋势越明显。动荷载峰值越大,隧道沉降越大;荷载峰值相同、振动次数一定时,荷载振动频率越低,隧道的竖向沉降越大。更多还原

【Abstract】 Research purposes: The settlement of subway tunnel in different level will be caused under the long-time vehicle dynamic load and it brings unfavorable effects on the stability of subway operation.The settlement is clearer especially in the saturated soft clay.It will help us to correctly understand the subway operation load of the surrounding soil by carrying out soil dynamic stability research under subway tunnel and provide the basis for soil around tunnel reinforcement. Research conclusions: Based on the analysis of stress characteristic during subway operation,a simulated experimental system is researched and built up.This paper investigated the dynamic stability of underlying silty clay of shield tunnel by model test.The dynamic characteristic in different amplitude and frequency of dynamic load was researched,also we analyzed the settlement of the subway tunnel.The test results shows that,the dynamic response of underlying silty clay presented attenuation trend with the increasing of space,the attenuation was more obvious when the distance was smaller,and the larger the value of dynamic load peak,the greater the tunnel settlement.The lower frequency,the greater the vertical settlement when the dynamic load has the same value and the vibration frequency is constant.更多还原