蛇行激振频率对铁路钢板梁桥横向振动的影响

针对我国铁路货车提速过程中出现的铁路上承式钢板梁横向振幅严重超限现象,将轮对蛇行波作为激励源,探讨了其频率对铁路钢板梁桥横向振动的影响.结果表明,当蛇行激振频率与桥梁横向固有频率接近时,列车桥梁发生横向共振,横向振幅最大.     

铁路桥梁横向振动模拟及适应快速行车结构型式的研究

针对铁路提速后出现的上承式简支钢板梁桥跨中横向振幅过大的问题,以羊楼司桥(L=32m单跨上承式简支钢板梁桥)为例进行实桥检测和数值模拟,建立车辆、线路、桥梁三者的联合模型,考虑轮轨接触力,应用MSC/DYTRAN大型结构分析程序进行车线桥动力相互作用的仿真分析。研究揭示我国用量最多的C62型货车以70∽80km/h的速度空载通过时,该跨度的钢板梁桥发生横向谐振的机理。此外,用该方法对32m跨长的组合梁结构进行桥梁动力特性及列车走行性分析,表明该结构满足提速货车和高速电动旅客列车走行的要求。研究结果对我国高速铁路桥梁建设和既有桥梁的改造具有积极意义。     

大跨度П形梁桥桥上列车横向摇摆力计算

将列车--П形梁桥视为一个整体系统,由弹性系统动力学总势能不变值原理及形成矩阵的"对号入座"法则,建立列车--桥梁系统横向振动方程,以机车车辆转向架实测蛇行波作为激振源,计算了列车--П形梁桥系统的横向振动,算出了列车通过П形梁桥时的车辆及桥梁横向振动响应全过程(从机车进桥至车尾离桥)波形图、列车横向摇摆力和侧倾力的波形图,分析这些计算结果,可以得出一些具有一定规律的现象.     

一种新型阻尼器的开发与研究

桥梁横向振幅超限一直是困扰铁路桥梁的一个重要问题。在全国铁路全面提速的大环境下,这个问题益发突出,列车速度的提高势必造成更大的桥梁横向位移,进而给行车安全造成不利的影响。传统的桥梁横向振动控制方法主要是通过改变桥梁自身刚度,达到减小桥梁振动响应的目的,但成本较高,经济性较差。耗能减振思想的提出为桥梁横向振动控制提供了一种新的思路,即用阻尼器加固桥梁。阻尼器的安装能够将输入桥梁的能量转化为阻尼器的滞回能,通过阻尼器的往复加卸载循环,先于结构消耗部分输入能量。这种方法的优势在于经济节省,易于更换,但目前国内尚缺乏该类型阻尼器产品及相关的应用研究。本文对铅橡胶阻尼器的结构及力学性能进行了阐述,提出该型式阻尼器能够适用于铁路横向小位移振动条件下的能量消耗。     

铁路既有线上承钢板梁提速后的横向刚度及加固问题

通过既有线铁路提速试验，分析了上承钢板梁横向刚度的要求，提出合理的加固方案．     

一种新型阻尼器的研究

桥梁横向振幅超限一直是困扰铁路桥梁的一个重要问题。在全国铁路全面提速的大环境下,这个问题益发突出,列车速度的提高势必造成更大的桥梁横向位移,进而给行车安全造成不利的影响。传统的桥梁横向振动控制方法主要是通过改变桥梁自身刚度,达到减小桥梁振动响应的目的,但成本较高,经济性较差。耗能减振思想的提出为桥梁横向振动控制提供了一种新的思路,即用阻尼器加固桥梁。阻尼器的安装能够将输入桥梁的能量转化为阻尼器的滞回能,通过阻尼器的往复加卸载循环,先于结构消耗输入能量。这种方法的优势在于经济节省,易于更换,但目前国内缺乏该类型阻尼器产品及相关的应用研究。本文研究的正是这种新型阻尼器。     

提速线连续钢桁梁桥横向刚度限值分析

基于列车脱轨能量随机分析理论,提出了预防列车脱轨的桥梁横向刚度限值分析方法。运用此方法,制定了提速线3×80 m连续钢桁梁桥横向刚度限值,为修订铁路钢桥设计规范提供参考。     

基于ANSYS软件对钢板梁桥的结构优化分析

以坦桑尼亚铁路桥为例,采用ANSYS有限元软件,从自重载荷、横向风载、交变载荷方面,对钢板梁桥的主梁进行了仿真分析,结合桥梁在三种载荷作用下的应变、应力情况,制定了针对性的加固措施,有利于桥梁结构的优化处理。     

某既有铁路钢板梁桥的疲劳验算与设计

采用新颁布的<铁路桥梁钢结构设计规范>(TB 10002.2-2005)对某铁路全焊上承式板梁桥的主梁进行疲劳验算,发现该铁路钢板梁桥主梁跨中截面、外层盖板端焊缝处、内层盖板变宽度连接焊缝处的疲劳强度均不满足新规范要求.按照新颁规范对主梁重新进行设计,提出钢板梁外层盖板理论切断点应按疲劳容许应力幅方法来确定的设计原则,并提出预防既有铁路钢板梁桥疲劳破坏的对策.     

铁路提速工程T形简支梁横向加固设计

兰新线武嘉段电气化提速工程中,大量既有铁路混凝土梁存在横向振幅超限的问题。结合武嘉段提速工程实际,侧重介绍简支梁的横向加固方案。     

Fatigue behavior and statistical evaluation of the stress category for a steel-concrete composite bridge deck

The maintenance cost of bridges is rapidly increasing since many existing bridges are deteriorating or reaching their design life all over the world. Moreover, as many long-span bridges are under construction and planning in Korea, research and development on bridge decks with high load-resistance capacity as well as high fatigue strength has become a growing concern. This research gives experimental results of the fatigue behavior of a new-type of steel-concrete composite bridge deck being developed under such circumstances. The proposed composite bridge deck consists of corrugated steel plate, welded steel ribs, stud shear connectors, and reinforced concrete filler. Fatigue tests were conducted under a four-point bending test with four different stress ranges in constant amplitude. In order to determine the influence of the concrete filling, fatigue tests on partial steel specimens containing only plain corrugated steel plates were performed in advance. The partial steel specimens and the steel-concrete composite deck specimens both showed fatigue failure in the tension part concerning the fillet welding part between the corrugated steel plate and steel rib. Finally, the stress category of the fillet welding part of each specimen is evaluated based on a statistical approach of Albrecht’s probability model. The research concludes that the fatigue behavior of such steel-concrete composite decks under sagging moment can be estimated based on the classical S-N approach, focusing on steel components.     

大跨径钢桥面铺装设计理论与方法研究

结合南京长江第二大桥、舟山桃夭门大桥、润扬长江公路大桥和杭州湾大桥等大型桥梁桥面铺装的研究与设计 ,对大跨径钢桥面铺装设计理论与方法 ,包括铺装材料与结构、钢桥面铺装体系受力特性、疲劳特性、热塑性沥青混合料铺装车辙、设计指标、轴载换算方法、设计方法等关键技术进行系统的分析与研究 ,研究成果已在多座大跨径钢箱梁桥面铺装设计和铺装工程中应用     

Development of fatigue test method and improvement of fatigue life by new functional steel plates for welding of trough rib and deck plate of orthotropic decks

Under heavy traffic conditions, some fatigue cracks have been found at welding joints between U-shaped ribs “trough ribs” and deck plates. Fatigue cracks along thickness direction of deck plate from root tip are important because visual crack detection from outside is limited. In this paper, new functional steel plates with initiation resistance of fatigue crack at weldment and propagation resistance at base material are applied to deck plate to evaluate improvement of fatigue life. We conducted fixed-point fatigue tests with real scale partial models consisted with one trough rib and a transverse girder, and the elastic FEM (Finite Element Method) analysis corresponding to the fatigue test specimen. Based on these results, we studied the fatigue properties which focused on the difference between conventional steel plates and newly developed steel plates, FCA (Fatigue Crack Arrester). Fatigue cracks were initiated from root tip of welded joints between a trough rib and a deck plate. It is clarified that FCA steel plates instead of conventional steel plates can improve the fatigue life under the same welding conditions. This improvement effect becomes much clearer in the high cycle region, which is noticeable at the operation and management stage of bridges.     

Component sizing approach for the sandwich plate system

The sandwich plate system (SPS) is a bridge deck system consisting of steel face plates bonded to a rigid polyurethane core. SPS bridges are typically constructed as a series of pre-fabricated SPS deck panels compositely connected with traditional steel girders. The decks are thin, lightweight and modular, and can be tailored to numerous applications including both new bridge and rehabilitated bridges.

With new system, there exist hurdles in the implementation; for SPS, the primary challenge is the lack of an established design method for the panel cross-sections. Presented herein is a method for sizing SPS panel sections for bridge applications. This method is limited to the selection of steel plate and core dimensions, subjected to American Association of State Highway and Transportation Officials (AASHTO) limit states of serviceability, strength and fatigue and does not consider connections or bond aspects of the system. The sizing approach considers the deck panels as plates with variable boundary conditions subjected to the loading conditions of the AASHTO Load Resistance Factored Design (LRFD) bridge design specification. Results from this study indicate that the component sizing for SPS deck panels is controlled by stiffness and that plates selected to satisfy the AASHTO limiting deflection criterion will also be adequate for the remaining serviceability, strength and fatigue limit states.     

不锈钢复合钢板在铁路钢桥上的应用技术

我国高速铁路钢桥均采用正交异性板钢桥面有碴线路。为提高钢桥面的防腐与使用寿命,合肥铁路枢纽南环线钢桁梁的桥面板采用了具有较高的强度、塑性、韧性、疲劳性能及优良抗腐蚀性能的321-Q345q-D不锈钢复合钢板。针对钢桥面系结构设计特点及制作与安装工艺需要,依据TB10212-2009《铁路钢桥制造规范》、GB/T13148-2008《不锈钢复合钢板焊接技术要求》,对321-Q345q-D不锈钢复合钢板进行焊接工艺试验,其试验结果(数据)均满足设计与施工要求。经对不锈钢复合钢板的钢桥面制作与安装实践,对铁路钢桥推广应用不锈钢复合钢板提出改进建议。     

正交异性钢桥面板纵肋与桥面板连接细节的疲劳评估及修复措施

正交异性钢桥面板由于具有自重轻、极限承载力大等优点目前广泛应用于大、中跨径桥梁中,我国已建和在建的大跨径桥梁也大多采用正交异性钢桥面板.但由于正交异性钢桥面板结构构造复杂,受焊接残余应力影响大,钢桥面板直接位于车轮荷载的作用下,一些构造细节处极易发生疲劳开裂.以国内某大桥正交异性钢桥面板为例,针对纵肋与桥面板之间的疲劳...     

福厦铁路钢系杆拱桥有砟钢桥面防护体系设计与施工工艺研究

福厦铁路木兰溪及丘后特大桥128m钢系杆拱桥采用有砟正交异性钢桥面的结构形式,由于以前国内对铜桥面上的防腐、防水技术和材料方面没有进行系统研究,因此,联合铁道科学研究院金属及化学研究所,结合这两座桥,进行钢桥面防腐、防水试验研究,根据研究成果完成福厦铁路铜系杆拱桥正交异性钢桥面防护体系设计及施工工艺研究。     

Parametric Study on the Interface Layer of Renovation Solutions for Orthotropic Steel Bridge Decks

Abstract: The article presents renovation solutions for orthotropic steel bridge decks consisting of bonding a second steel plate to the existing steel deck in order to reduce the stresses and enlarge the life span of the orthotropic bridge deck. Two solutions for the interface layer between the existing deck plate and the second steel plate are presented: thin epoxy (bonded system) and thick polyurethane (sandwich system). A parametric study based on analytical solutions is carried out on flexural behavior of beams representing the renovation solutions. The influence of geometrical, mechanical and structural parameters on the stiffness and stress reduction factor of the system is studied. Maximum values of stiffness and stress reduction are achieved when maximizing the interface layer thickness and minimizing the second steel plate thickness with in certain practical limits. Based on the weight restrictions one can choose the most efficient interface layer regarding thickness and mechanical properties.     

#br# 我国钢管混凝土拱桥应用现状与展望

共收集到截止2015年1月的已建和在建的钢管混凝土拱桥413座（跨径不小于50m）。统计分析表明,钢管混凝土拱桥在我国修建的数量不断增多、跨径不断增大。从行业分布来看,在公路、城市桥梁中的应用仍是主体,在铁路尤其是高速铁路中的应用不断增多。在结构体系方面,上承式、中承式、拱梁组合式、飞鸟式和下承式刚架系杆拱5大类,仍为主要应用的桥型,占总数的85%。在截面形式方面,以圆钢管混凝土为基本单元组成的单圆管、哑铃形和桁式是应用的主流。提篮拱被应用于各种桥型,尤其是大跨度铁路桥。无风撑拱主要应用于120m跨径以下的桥梁,且以斜靠拱和拱梁组合桥为主,截面多采用横向刚度较大的形式。拱肋的材料强度不断地提高,钢管以Q345钢为主,混凝土以C40、C50为主。虽然对桥面系强健性的重视在不断提高,然而强健性好的整体式和具有加劲纵梁的悬吊桥面系的应用还不够普及。钢管拱的架设方法仍以支架法、悬臂法和转体法3种为主,其中悬臂拼装法应用最多,适用跨径最大范围也最广。