层状地基中隔振沟对移动列车荷载隔振研究-2.5维IBEM方法  

Reduction of train-induced vibrations by using a trench in a layered foundation

作　　者：巴振宁[1,2] 王靖雅[1] 梁建文[1,2] 

机构地区：[1]天津大学土木系,天津300072 [2]滨海土木工程结构与新材料教育部重点实验室,天津300072

出　　处：《振动工程学报》2016年第5期860-873,共14页Journal of Vibration Engineering

基　　金：天津市应用基础与前沿技术研究计划(自然科学基金)青年项目(12JCQNJC04700);国家自然科学基金资助项目(51578373))

摘　　要：建立层状地基-轨道-隔振沟耦合动力系统,采用2.5维间接边界元方法 (IBEM)研究了层状地基中隔振沟对移动列车荷载下地基振动的隔振问题。采用子结构方法,将系统分解为含隔振沟的层状地基和轨道子结构,采用2.5维IBEM方法求得含隔振沟层状地基在移动均布荷载作用下的层状地基柔度,然后通过地基表面轨道中心点的竖向位移与轨道竖向位移相等将轨道和层状地基耦合。通过与已有结果的比较验证了方法的正确性,并对不同地基、隔振沟参数下的模型进行了算例分析。研究表明:不同地基模型下隔振沟有不同的隔振效果,且隔振沟深度及其与轨道距离均对隔振效果有不同程度的影响。通过对瑞典X2000高速列车在实际软土地基上的隔振计算发现,隔振沟的隔振效果随着沟深的增加而增大,且相对低频区域而言,隔振沟对高频区域的隔振效果更好。An analysis model of a coupled layered foundation-track-trench system is developed to investigate the isolation effect of a trench on reducing vibration generated by a moving train in a layered foundation. The system is decomposed into a track and a layered foundation including a trench through a substructure method. The 2. 5D indirect boundary element method is firstly proposed to obtain the compliance of the layered foundation including a trench. Then the track and the layered foundation are coupled via making the vertical displacement of the center point of the track equal the vertical displacement of the track. The method is validated by comparing its results with published ones. Then numerical analyses are performed for different models with different parameters of the trench under various soil conditions. The results show that the isolation effects of the trench are different for different soil conditions and different geometric parameters, such as the depth and location of the trench. The analysis result of the Swedish high-speed train X-2000 which runs on soft soil at Ledsgard shows that the isolation effect improves as the trench depth increases. In addition, the isolation effect of the trench for the high frequencies is better than those for the low frequencies.

关 键 词：层状地基 列车移动荷载 2.5维间接边界元 隔振沟 轨道 

分 类 号：TU435[建筑科学—岩土工程] U260.17[建筑科学—土工工程]