【作者】 孙晓静；

【导师】 刘维宁；

【作者基本信息】 北京交通大学 ， 桥梁与隧道工程， 2008， 博士

【摘要】 随着城市轨道交通的快速发展和地面结构物的大量修建,地铁线临近精密仪器使用单位的情况时有发生,便捷的轨道交通与精密仪器的正常工作形成无法回避的矛盾,需要进行专门的研究。本文以北京地铁4号线成府路站及南北区间工程为背景,研究了地铁列车运行对北京大学理科试验基地内精密仪器的振动影响。采用现场测试、数值模拟、试验室试验和理论分析等多种手段,从地铁列车振源特性、地表振动响应规律、钢弹簧浮置板轨道减振性能、振动对环境的影响预测等方面进行了比较系统全面的研究。主要的工作和研究成果如下:1、全面系统地总结了北京市地铁线路的减振设计及应用现状,分析了北京市新建线路中采用较高及特殊减振措施的技术参数,包括线路长度比例、投资比例、钢弹簧浮置板轨道的设计使用比例等。2、分别在北大物理楼内和楼外、地铁1号线东单—建国门区间、地铁5号线东单—灯市口区间进行了振动测试,对北大物理楼内和楼外、地铁既有线地表背景振动进行了评价,比较了路面车流和地铁列车单独作用及共同作用引起的地表振动响应特性,获得了普通轨道及钢弹簧浮置板轨道的振动响应频率特性,并依此得到了实测模拟列车荷载。3、研究了地层、隧道结构、隧道—土层各系统的振动特性,分析了离散数值模型与连续介质的波动特性差异、阻尼特性的处理及积分步长的确定、人工边界的选取等问题,根据实测结果得到了可用于计算的列车荷载。在此基础上,对东单—建国门测试区间进行数值分析,并利用实测数据对计算模型进行修正,验证了模型参数、边界处理和列车荷载等的合理性。4、在北京交通大学地下轨道减振工程试验室内,对钢弹簧浮置板轨道及普通轨道两种轨道型式进行了1∶1的原型振动试验,分析了钢弹簧浮置板轨道的工作频率、减振频率特征及振动响应衰减特性,得到了5～15Hz频段内的传递系数以及传播路径中关键位置的减振量。5、对地铁4号线运营阶段北大段的环境振动进行预测,研究了轨道及隧道质量对地表振动响应的影响,分析了钢弹簧浮置板轨道的减振效果,对北大段隧道型式和轨道结构的选择提出建议,并结合现有减振产品提出了综合减振措施建议。更多还原

【Abstract】 With the rapid development of the urban rail transit system and the constructing of buildings, it is of common occurrence that metro lines are near the buildings where installed sensitive instruments. Accordingly, it is unable to avoid the vibration effects on sensitive instruments induced by metro trains, which needs special researches.Based on Beijing Metro Line 4 passing through under the Peking University science tests, the characteristics of vibration resource, ground-surface vibration propagation regular, performance of SSFST, and vibration prediction have been researched roundly in this paper. The research methods include in situ measurement, numerical simulation, model test, theoretical analysis etc. The conclusions are universal, which can supply references to the related researches. The main work and the achievement are as follows:The present states of vibration mitigation design and application in Beijing metro line were summarized roundly, and the technical parameters of mitigation measures for more and the most sensitive areas of new metro lines in Beijing were obtained, including length ratios, investment ratios, the application of SSFST and so on.The in situ measurements were carried out inside and outside the Physical Laboratory, on the ground surface and in the running tunnel between Dongdan station and Jianguomen station, and in the running tunnel between Dongdan station and Dengshikou station. According to the measured data, the background vibrations of the Physical Laboratory and the existing metro line were evaluated; the ground-surface vibration response characteristics induced by metro trains, by road traffic and by their combined action were analyzed; and the vibration resource characteristics of the unisolated track and SSFST were obtained, with which the train loads were simulated.The vibration characteristics of the stratum, the tunnel structure and the tunnel-soil system were researched, and some issues were analyzed in detail, including the differences of vibration performance between the discrete numerical model and the continuous media, the damping treatment, the integral step determination and the choice of artificial boundary. Besides, the simulated train loads were transformed for using in the finite element model. Finally, a dynamic finite element model corrected by the measured data was established to simulate the ground-surface vibration induced by metro trains between Dongdan station and Jianguomen station, and the compared results between the calculated and measured data proved that the treatment of relative parameters, the boundary and the train load were credible.The 1:1 scale model vibration tests were carried out for the case of the unisolated and the isolated track in the UTEL of Beijing Jiaotong University. Based on the test data, some major parameters of SSFST were analyzed, such as the working frequency, the frequency characteristic of vibration mitigation, and the attenuation regular. Besides, the transfer coefficient and the vibration decrement of key point in the transmission path were given, which were in the range of 5Hz and 15Hz.On the assumption that Line 4 were operating, the environment vibrations of the Peking University were predicted for the case of the unisolated and the isolated track. By analyzing the mass effects on the ground-surface vibration of the track and the tunnel, the comprehensive proposal for the metro tunnel north of Chengfulu station were presented, including type of the running tunnel and the track, and other mitigation technologies.更多还原