客运专线涵—涵过渡段动力特性试验研究及仿真分析

【作者】 张协崇；

【导师】 王永和；

【作者基本信息】 中南大学 ， 岩土工程， 2009， 硕士

【摘要】 高速铁路的发展必须以安全、可靠、舒适等为前提,这些取决于铁路系统各方面的高品质和高可靠性。过渡段问题是高速铁路必须解决的关键技术之一。本文在广泛查阅国内外相关研究成果的基础上,以武广客运专线涵-涵过渡段为工程背景,以国家自然科学基金项目为依托,采用数值摸拟和现场试验相结合的方法,研究动车荷载作用下不同条件的涵-涵过渡段的动力响应特性,获得了许多具有重要的实际工程参考价值的测试数据和研究结论。主要的研究工作和结论如下:(1)针对武广客运专线DK1252+679～+731涵-涵过渡段工点详细制定了动力特性研究方案:获取参数试验方案设计、现场实施及数据处理分析;ANSYS建立仿真分析有限元模型并进行仿真计算研究分析过渡段的动力特性;进行过渡段现场动测试验,并对比分析研究仿真与实测结果。(2)现场波速测试试验得到:级配碎石,A、B填料,粘土层的平均E_d分别为1716MPa,793MPa,596MPa;平均G_d分别为659MPa,295MPa,219MPa。(3)利用ANSYS软件建立涵-涵过渡段有限元仿真计算模型,并进行仿真研究过渡段的结构动力特性:①行车速度在350km/h下,涵-涵过渡段结构的动力作用:动位移在纵向上成“M”形分布;竖向上各动响应值均是随深度增加而减小,其中动位移减小的速率较小,其它三者近似双曲线或指数曲线减小;②行车速度的影响:行车速度从150km/h～350km/h增长时,路基的动响应值随速度增大而缓慢增大;当行车速度从350km/h～400km/h增长时,在路基本体为A、B填料的普通路基上,动位移、加速度和速度三个动响应值皆迅速上升;这说明了如果要继续提速则必需改善普通路基的结构,或提高路基本体A、B填料的工程特性。③基床表层厚度增加可适当改善过渡段中普通路基段的动响应,尤其是改善轨下正下方路基本体的动响应。当行车速度继续增加,这种改善作用会更加突出。④涵-涵中心距变化主要对动位移的影响比较大,对动应力、加速度、速度的影响很小。涵-涵中心距为43.2m时,过渡段的动位移值最大,比其它涵间距要大出12%。(4)现场动测数据分析研究,统计分析结果表明实测数据基本符合正态分布,将实测与仿真结果对比偏差较小,总体变化趋势比较吻合:动响应值皆随着行车速度的增大而增大;加速度在基床表层以下,沿竖向向下呈指数趋势或双曲线趋势减小;动应力在两涵洞处的最大,中间部分路基的较小;涵-涵间路基面的动位移沿纵向的分布呈“M”型。(5)通过对涵-涵相邻过渡段的动响应实测和仿真分析,了解了在不同速度运行的动车荷载作用下的动应力、动位移、加速度等动响应值的大小及其分布规律,为相邻过渡段的设计、施工提供了重要的参考。更多还原

【Abstract】 The precondition of the development of high-speed railway is safety, reliability and ride comfort that are decided by the high quality and high reliability of all aspect of the railway system. The transition section is one of the must key technologies. The thesis which is combined with the state natural science fund item has studied the dynamic response characteristics of the different conditions’ culvert-culvert transition sections under the train load influence. It has adopted the combination of numerical modeling and field test, on the ground of the Wu-Guang passenger railline and on the basis of lots of relevant research at home and abroad. It has gained a number of the test datas and research findings which is valuable for the actual construction. The main research work of this dissertation gained can be summarized as below.(1) Research precept about the dynamic response of culvert-culvert transition section on the WuGuang passenger line DK1252+679～+731 has been instituted: precept design、on-site implementation、data processing and analysis of parameter obtainment test; the finite element simulation model’s built by ANSYS、research and analysis of the dynamic response characteristics of transition section on the model; field dynamic test、comparative analysis between simulation and field test.(2) It has been gained on parameter obtainment tests that the average E_d of grading macadam, A、B fillers, clay layers were 1716MPa、793MPa、596MPa and the average G_d of grading macadam, A、B fillers, clay layers were 659MPa、295MPa、219MPa.(3) Built the finite element simulation model of culvert-culvert transition sections by ANSYS and simulation analyse the dynamic response characteristics of transition sections on the model. The main results of simulation analysis include:①Under the 350km/h speed of train, the dynamic response characteristics of culvert-culvert transition sections can be described as follows. Dynamic displacement distributes into "M"-shaped in the longitudinal direction. Each dynamic response decreases with increaseing depth, among which dynamic displacement decreases slowly and the others three decrease as hyperbolic or exponential curve.②The impact of the train speed can be described as follows. When train speed increases from 150 km/h to 350 km/h, the dynamic responses of transition sections imcrease slowly. When train speed increases from 350 km/h to 400 km/h, dynamic displacement、acceleration and vibration velocity increase quickly on the ordinary subgrade of A、B fillers. Thus only if the structure of the ordinary subgrade or the engineering performance of A、B fillers is improved, the train speed could increase.③Increase of subgrade surface layer’s thickness can improve dynamic responses of ordinary subgrade, especially under the rail. When train speed increases, the improvement becomes more.④The distance between two culverts’ centers has a great influence on dynamic displacement but little on the other three. When the distance is 43.2m, dynamic displacement is maximum and 12% more than the other distances.(4) It indicates that test data almost accord with gaussian distribution to analyse field dynamic test data. With comparative analysis between simulation and field test, the difference is a little and main transformation is similar as follow. Train speed increases and dynamic responses increase. Under subgrade surface layer, acceleration decreases as hyperbolic or exponential curve. In the longitudinal direction , dynamic stress is large on the culverts and small in the middle. Dynamic displacement on the subgrade surface distributes into "M"-shaped in the longitudinal direction.(5) It is indicated the value and distribution of dynamic displacement、dynamic stress、acceleration and vibration velocity with a variety of conditions by dynamic test and simulation analysis, which would provide an important reference for the design and construction of adjacent transition sections.更多还原