【作者】 夏超逸；

【导师】 雷俊卿；

【作者基本信息】 北京交通大学 ， 桥梁与隧道工程， 2012， 博士

【摘要】 随着科学技术的发展和新型材料的应用,铁路桥梁跨度不断增大,列车速度不断提高,桥梁的振动问题日趋突出。与此同时,随着水运、铁路、公路交通的日益繁忙,船舶、流冰、车辆撞击桥梁结构的事故也越发频繁。本文在国家自然科学基金项目“撞击荷载作用下车桥系统的动力响应及列车运行安全控制研究(51178025)”和“河冰物理力学性能及其对桥梁撞击作用机理的研究(50878020)”的资助下,针对撞击荷载引起的桥梁结构振动以及由此引发的桥上高速列车的运行安全问题,展开了较深入的研究。主要研究内容和创新点包括：(1)对国内外桥梁遭受船舶、汽车和流冰等撞击而引发重大事故的情况和相关的研究现状进行了综述,阐述了研究撞击荷载引起的桥梁振动和列车运行安全问题的必要性,总结了一般车桥动力相互作用问题的研究内容及主要研究方法,说明了论文的选题意义和立项依据。(2)结合国内外铁路、公路设计规范和相关研究成果,总结了船舶、车辆和流冰撞击荷载的设计方法以及理论分析、数值模拟和试验结果。分析了各种撞击荷载的持时、最大幅值、作用位置等特点,为确定列车-桥梁系统动力分析模型中的撞击荷载取值方法提供了依据。(3)在佳木斯松花江公路大桥、通河松花江公路大桥等地进行了河冰温度场及流冰撞击荷载现场试验。通过河冰温度场试验,得到了流冰期气温、水温与河冰温度的相关关系。通过流冰撞击荷载试验,得到了流冰撞击桥墩的撞击力时程曲线,为撞击荷载作用下的车桥耦合振动分析提供了实测撞击力数据。采用快速傅立叶变换对实测流冰撞击力时程进行了频谱分析,获得了撞击力的离散频谱并对其特性进行了分析。(4)建立了撞击荷载作用下的车桥耦合系统动力分析模型,编制了相关的计算程序,其中车辆模型采用多刚体动力学方法建立,桥梁模型采用振型叠加法建立,轮轨垂向作用力按照轮轨密贴假定定义,轮轨横向作用力按照简化的Kalker蠕滑理论定义,撞击力作用时程以节点动荷载模拟。提出了一种适用于车桥动力耦合系统时程积分的全过程迭代法,通过算例说明了其计算效率。(5)利用所建立的计算模型和自编程序,以九江长江大桥为实例,按照我国普通旅客列车和美国五级谱轨道不平顺条件,通过模拟计算,考虑有无船舶撞击两种情况,对桥梁墩顶和跨中的横向位移和加速度响应以及列车的脱轨系数等运行安全指标进行了时程分析,并将桥梁位移响应的计算结果与2007年现场实测的一些数据进行了比较,部分地验证了本文方法。在此基础上,按照德国ICE3高速列车和秦沈客运专线轨道不平顺条件进行了计算,并与普通列车的计算结果进行了综合分析比较,结果表明荷载撞击桥梁对高速列车的影响比普通列车大。(6)以哈大高速铁路(32+48+32)m预应力混凝土连续箱梁桥为分析对象,考虑佳木斯流冰、通河流冰、船舶三种类型的撞击荷载,对桥梁墩顶、主跨跨中的位移和加速度响应以及ICE3高速列车的脱轨系数、轮重减载率和轮轨横向力等运行安全指标进行了时程分析。在此基础上,通过进一步的参数分析,系统地研究了撞击荷载类型、撞击强度、列车速度、列车类型等对桥上列车运行安全指标的影响规律。(7)对撞击荷载作用下高速铁路桥梁上列车的运行安全控制方法进行了初步的探讨,提出了撞击荷载作用下保障桥上列车运行安全的撞击强度-列车速度阈值曲线的确定方法。通过系统的模拟计算分析,得到了高速铁路(32+48+32)m预应力混凝土连续箱梁桥在佳木斯流冰(多次连续脉冲)、通河流冰(单次窄脉冲)、船舶(单次宽脉冲)三种类型撞击荷载作用下,德国ICE3、日本E500、国产CRH2三种列车在桥上安全运行的撞击强度-列车速度阈值曲线。更多还原

【Abstract】 With the development of science and technology and application of new materials, the bridge span becomes longer and the train speed becomes faster. Meanwhile, as the water, railway and highway traffics become increasingly busy, collisions of vessels, vehicles and ice-floes on bridges crossing rivers and roadways also become more serious. In this dissertation, the bridge vibration induced by collision loads and the related running safety problem of high-speed train on bridge subjected to collision are studied, which is funded by the National Natural Science Foundations "Dynamic responses of railway bridges subjected to collision loads and running safety control of vehicles (Grant No.51178025)" and "Research on mechanism of physical and mechanical properties of river ice action and its effects on railway bridges (Grant No.50878020)". The detailed contents and highlights of the study include:(1) The serious accidents of bridges subjected to collision of vessels, vehicles and ice-floes and the related research situation in China and abroad are reviewed, and the necessity of research toward running safety of high-speed train on bridge subjected to collision load is elaborated. The research contents and general analysis methods of train-bridge dynamic interaction problem are summarized, and the significance and research basis of this doctoral dissertation are introduced.(2) The design methods, numerical simulation and experimental results of collision loads induced by vessels, vehicles and ice-floes are summarized, by referencing the highway and railway bridge design codes and the related researches in China and abroad. The characteristics of collision loads, such as duration time, maximum values and loading positions are analyzed, which provides an important basis to determine the collision loads for dynamic analysis of train-bridge interaction system.(3) The field experiments were carried out to measure temperature fields and ice-floe collision forces at the Jiamusi Songhuajiang Highway Bridge, the Tonghe Songhuajiang Highway Bridge, and several other sites. The relationships between air, water and ice temperature were obtained from the river ice temperature field measurement. The collision loads of ice-floe on bridge piers were obtained from the collision force measurement, which provides experimental data for the dynamic analysis of coupled train-bridge system. The frequency spectrum analysis is done with the FFT method on the measured ice-floe collision data, and then the features of discrete frequency spectra are analyzed.(4) The analysis model of train-bridge interaction system subjected to collision loads is established, and the computer code is written, where the vehicle submodel is established with multi-rigid-body dynamics, the bridge submodel is established with modal superposition method, the vertical wheel-rail force is defined with the wheel-rail close contact assumption, the lateral wheel-rail force is defined with the Kaller’s Creep Theory, and the collision force is simulated as nodal dynamic load. Moreover, a new iterative method of whole process is proposed, which is suitable to the time history integral of train-bridge interaction system, and the calculation efficiency is proved through case study.(5) With the analysis model and the computer code, by taking the Jiujiang Yangtze River Bridge as a case study, whose main pier is subjected to vessel collision load, and considering a normal passenger train and the US Grade5irregularity spectrum as calculation conditions, the lateral displacements and accelerations at pier-top and mid-span of the bridge and the running safety indices of the train are calculated through computer simulation. Some of the calculated results are compared with the measured results obtained in the field experiment in2007, which partly proved the proposed method. On the basis, further calculation is performed with the German ICE3train running on the bridge and with irregularity samples measured from the Qinhuang-Shenyang high-speed railway, and the results are compared with the ones from ordinary passenger train, which shows that the high-speed train is more seriously affected than the ordinary train when the bridge pier is subjected to collision load.(6) For the (32+48+32) m continuous PC box girder bridge on the Harbin-Dalian high-speed railway, by assuming one of its piers collided by Jiamusi ice-floe, Tonghe ice-floe and vessel loads, the displacements and accelerations at pier-top and mid-span of the bridge and the derailment factors, offload factors and lateral rail-wheel forces of ICE3high-speed train are analyzed. By further parameter analysis, the influences of collision load types, collision intensities, train speeds and train types on the running safety indices of the train are studied.(7) A preliminary investigation is performed on the control method for running safety of train on high-speed railway bridge subjected to collision load, and the definition for threshold curves between train speed and impact intensity for running safety of train is proposed. Through systematical numerical simulation, the threshold curves between train speed and impact intensity for running safety of several trains including ICE3, Japan E500and China CRH2on the (32+48+32) m continuous PC box girder bridge which is subjected to three types of loads, Jiamusi ice-floe (successive multi-impulse), Tonghe ice-floe (single narrow impulse) and vessel (single wide impulse), are acquired.更多还原