Design and evaluation of UHPP steel bridge deck pavement for high-temperature and rainy regions

To enhance the serviceability of steel bridge deck pavement(SBDP)in high-temperature and rainy regions,a concept of rigid bottom and flexible top was summarized using engineering practices,which led to the proposal of a three-layer ultra-high-performance pavement(UHPP).The high-temperature rutting resistance and wet-weather skid resistance of UHPP were evaluated through composite structure tests.The internal temperature distribution within the pavement under typical high-temperature conditions was analyzed using a temperature field model.Additionally,a temperature-stress coupling model was employed to investigate the key load positions and stress response characteristics of the UHPP.The results indicate that compared with the traditional guss asphalt+stone mastic asphalt structure,the dynamic stability of the UHPP composite structure can be improved by up to 20.4%.Even under cyclic loading,UHPP still exhibits superior surface skid resistance compared to two traditional SBDPs.The thickness composition of UHPP significantly impacts its rutting resistance and skid resistance.UHPP exhibits relatively low tensile stress but higher shear stress levels,with the highest shear stress occurring between the UHPP and the steel plate.This suggests that the potential risk of damage for UHPP primarily lies within the interlayer of the pavement.Based on engineering examples,introducing interlayer gravel and optimizing the amount of bonding layer are advised to ensure that UHPP possesses sufficient interlayer shear resistance.

Elastoplastic bridge deck response spectra of high-speed railway simply-supported girder bridge with CRTS Ⅱ track system

The seismic damage to ancillary facilities on high-speed railway(HSR)bridges can affect the normal movement of trains.To propose the bridge deck acceleration response spectra of the typical HSR simply-supported girder bridge for simplifying the seismic responses analysis of the facilities on bridges,the finite element models of the HSR multi-span simply-supported girder bridges with CRTSII track were established,and the numerical model was validated by tests.Besides,the effects of the span number,peak ground acceleration(PGA),pier height on the seismic acceleration and response spectra of the bridge deck were investigated.Afterward,the bridge acceleration amplification factor curves and bridge deck response spectra with different PGAs and pier heights were obtained.The formula for bridge deck acceleration amplification factor,with a 95%guarantee rate,was fitted.Moreover,the finite element models of the overhead contact lines(OCL)mounted on rigid base and bridges were established to validate the fitted formula.The results indicated that the maximum seismic acceleration response is in the midspan of the beam.The proposed formula for the bridge deck acceleration response spectra can be used to analyze the earthquake response of the OCL and other ancillary facilities on HSR simply-supported girder bridges.The bridge deck acceleration response spectra are conservative in terms of structural safety and can significantly improving the analysis efficiency.

落石撞击钢筋混凝土箱梁数值仿真与损伤分析

为研究落石撞击对钢筋混凝土箱梁的影响,通过ANSYS/LS-DYNA有限元软件对落石撞击某匝道桥箱梁的过程进行数值模拟,计算竖直方向的落石撞击力,分析桥面破损情况和箱梁开裂形态,并与现场检测结果进行对比。结果表明:落石与箱梁发生了5次撞击,产生了多个撞击力峰值,桥面出现5处凹坑;落石撞击力类似三角形脉冲荷载,瞬时峰值大,持续时间短;首次撞击时落石撞击力最大,瞬时峰值达到10705 kN,基于瑞士公式和日本道路公团公式计算的最大落石撞击力比模拟值小,将其直接用于落石-箱梁碰撞计算是偏不安全的;有限元计算得到的桥面凹坑分布和箱梁开裂破损情况与事故测量结果吻合较好,再现了落石撞击钢筋混凝土箱梁的过程;落石撞击箱梁所造成病害主要是碰撞接触区域的局部损伤,首次撞击时病害最严重,桥面破损范围大,箱梁翼缘板上表面混凝土开裂并向下延伸至翼缘与腹板交界处。

基于数值模拟的等跨连续梁桥冲击系数研究

本文为确定等跨连续梁桥的冲击系数,根据结构静力分析,求取边跨及中跨跨中挠度静力响应;基于结构动力学原理,分别建立车辆与桥梁的动力方程,采用五轴十三自由度平面车辆模型,三跨连续梁桥模型,建立车桥耦合振动方程,采用ANSYS和MATLAB软件编译等跨连续梁桥车桥耦合分析模块,迭代求解边跨及中跨跨中挠度动力响应;再依据冲击系数计算公式求出边跨及中跨冲击系数,确定桥面不平整度、速度、基频和载重这4个因素为影响因素,利用SPSS (statistical package for the social sciences)数值分析软件进行逐步回归,得到了各参数对冲击系数的显著程度,给出等跨连续梁桥挠度冲击系数计算公式。结果表明:桥面不平整度与挠度冲击系数的相关性较好,而速度、基频和载重对挠度冲击系数的线性相关较为不显著;回归分析结果显示,桥面不平整度与冲击系数之间的标准化相关系数Beta达到0.908,表明桥面不平整度对连续梁桥的冲击系数具有重要影响。然而,现行规范未考虑到这一因素,因此建议在后续规范修订中纳入桥面不平整度的影响。

高性能混凝土铺装层对正交异性钢桥面疲劳应力消减效应实测与量化研究

铺设高性能混凝土层能够显著降低正交异性钢桥面疲劳应力,从而提升其疲劳性能。依托宜宾临港公铁平层长江大桥工程,采用足尺模型疲劳试验和有限元模拟进行钢纤维混凝土层对钢桥面疲劳应力消减效应的定量分析。通过钢-混组合桥面足尺模型静力和疲劳试验,观测钢桥面易损细节的疲劳应力和混凝土层开裂情况。根据足尺模型建立有限元模型并验证其合理性,基于有限元模型进行参数分析,探明影响钢桥面疲劳应力消减作用的关键因素。结果表明:混凝土层对钢桥面的疲劳应力消减作用主要受混凝土层和钢桥顶面刚度影响,深度不超过混凝土保护层的裂缝的不利影响可忽略。提出的疲劳应力消减作用量化公式可为正交异性钢-混组合桥面优化设计提供参考。

开口T形加劲肋正交异性钢桥面板疲劳性能研究

为了分析并对比采用开口T形加劲肋形式正交异性钢桥面板的疲劳性能,采用Midas Civil建立全桥模型,提出横隔板顶部不开孔的开口T肋正交异性钢桥面板、横隔板顶部开孔的开口T肋正交异性钢桥面板、闭口U肋共3种设计方案,采用Abaqus分别建立局部三维实体模型,对3种设计方案展开参数分析,并采用热点应力法进行疲劳性能评估。结果表明,全桥疲劳易损断面位置处于跨中顶板厚度为18 mm的E类梁段。方案3在各个疲劳构造细节处的热点应力幅均高于方案1和方案2。方案1仅在疲劳构造细节⑤处的热点应力幅小于方案2,其余几个疲劳构造细节的应力幅均高于方案2,在疲劳构造细节①处的热点应力幅降幅最大,约为34.75%,在疲劳构造细节③的热点应力幅降幅最小,仅为7.16%。无论顶板厚度变化还是横隔板厚度变化,变化幅度最大的位置均是疲劳构造细节①和②,其余位置疲劳应力幅对于顶板厚度变化较横隔板厚度变化敏感。方案2并无超出热点应力S‑N曲线疲劳截止限的位置,而方案1和方案3超出疲劳截止限的位置疲劳性能均满足规范中对正交异性钢桥面板疲劳性能验算的要求。

基于车桥耦合振动的双层钢桁梁斜拉桥行车舒适度分析

探究车辆在双层钢桁梁斜拉桥的行车舒适性,为优化双层桥梁结构设计理论提供依据。以车桥耦合振动理论为基础,利用ANSYS分析软件进行数值模拟,通过求解车体的振动加速度,并根据《机械振动和冲击—评估人体暴露于全身振动的情况》(ISO2631-1)中均方根乘值法对乘车舒适性进行评价,探究了单(双)层加载、车速、车载质量、桥面不平顺度、车辆间距、车辆数目等因素对行车舒适性的影响。相较于单层通车,上下层同时通车时车体的振动强度略微降低;当车载质量越小或车速越大时,车体的加速度均方根值会逐渐增大;路面对车体振动强度影响较大,当路面等级处于较差的D级和E级时,车体振动强度会成倍增加。双层同时加载时,车辆的行车舒适性略优于单层通车;保持适当的车速或增大车载质量可以提高司乘人员的行车舒适性;行车舒适性对于路面等级较为敏感,当路面等级较差时,车内司乘人员受其影响无法长时间乘车。

Analysis on cracking of deck pavement on Jiangyin Bridge

Based on four-year field inspection and investigation on deck pavement of mastic asphalt on Jiangyin Bridge, cracking causes of mastic asphalt are studied. Cracks of deck pavement are summarized on crack length and width to get a clear view of their propagations. Traffic surveys including traffic volume, axle load and vehicle speed were also conducted to assess their influences. Samples taken on-site were tested with pulling-out test and fatigue test to benchmark their properties. According to the inspection and tests results, it is concluded that the cracks are induced by rutting and fatigue. Lack of fatigue resistance, not well bonded to the steel deck and insufficient high temperature stability are supposed to be the main reasons as well as high density of low speed, excessively overloaded trucks.

Interfacial behaviors of epoxy asphalt surfacing on steel decks

A model for predicting the interface behavior of epoxy asphalt and steel composite beam under negative bending is developed incorporating partial interaction theory. Interfacial slips between the steel deck and the epoxy asphalt surfacing are included in the model with a new parameter of membrane stiffness. A series of analytical equations based on this model are derived to calculate slip and strain at the interface. Also, a numerical procedure for calculating the load responses of simply supported composite beams with concentrated force at the mid-span is established and verified with two samples. Characters of slip and strain at the interface, sensitivities of tensile stress and interface shear stress with material parameters are studied. It can be concluded that interfacial effects decrease the bending stiffness of the composite; hard and stiff bonding material is better for asphalt surfacing layer working at normal to low temperatures, and the damage of the asphalt surfacing layer will be accelerated with the damage accumulation of the bonding coat.

斜拉桥钢桥面板挖孔细节群的数字畸变疲劳试验

为研究斜拉桥钢桥面板横隔板挖孔细节群的畸变疲劳机理,考虑疲劳应力、焊接残余应力、焊接缺陷等多场耦合作用,建立了斜拉桥全桥足尺数字疲劳孪生模型,实现了钢桥面板典型细节群的数字畸变疲劳试验与模拟。焊接数字孪生模拟时,采用与单元温度相关联的热对流参数表达,可显著改善焊接温度场和残余应力场模拟准确度。数字畸变疲劳试验与模拟结果表明,横隔板挖孔细节群的畸变疲劳裂纹尖端等效应力强度因子幅均大于门槛值,该细节群初始裂纹在运营卡车荷载作用下易于扩展。应变能释放率分析结果表明,横隔板挖孔细节群的畸变疲劳裂纹均是以Ⅰ型裂纹为主导的Ⅰ-Ⅱ-Ⅲ型复合型裂纹,扩展全过程3种类型裂纹耦合特征显著。该研究成果可为斜拉桥钢桥面板抗疲劳设计与维护提供依据。

Finite element simulation and optimal analysis of surfacing on steel orthotropic bridge deck

To analyze the stress state of steel orthotropic deck pavement and provide reference for the design of the overlay, the inner stress state and strain distribution of surfacing under the load of the deformation of the whole bridge structure and tyre load are analyzed by the finite element method of submodeling. Influence of surfacing modulus on the strain state of the overlay is analyzed for the purpose of the optimal design of the overlay structure. Analysis results show that the deformation of the whole bridge structure has no evident influence on the stress state of the overlay. The key factor of the overlay design is the transverse tensile strain in the overlay above the upper edge of web plate of rib. The stress state of the overlay is influenced evidently by the modulus of rigidity transform overlay. And the stress state of the overlay can be optimized and lowered by increasing the modulus and thickness of rigidity transform overlay, The fatigue test has been done to evaluate the fatigue performance and modulus of different deck pavement materials such as epoxy asphalt, SBS modified asphalt, rosphalt asphalt which can provide reference for deck pavement structure design.

Dynamic analysis of pavement on long span steel bridge decks

In order to analyze the dynamic response of pavement on long-span steel bridge decks under random dynamic loads, the irregularities of the pavement surface is simulated with the power spectrum density function, and the random load is calculated according to a vehicle vibration equation of vehicle model. The mechanical responses of three different cases are compared by using a transient dynamic analysis method, i. e., under random dynamic load, constant moving load and dead load respectively. The results indicate that the mid-span of two adjacent transversal diaphragms is the worst load position. The maximum vertical displacement and the maximum transversal tensile stress of the pavement are 1.33 times and 1.39 times as much as those when only considering the impact coefficients. This study not only provides a theoretical basis for the mixture design and structural design of pavement, but also puts forward higher demand on the construction and maintenance for steel deck pavement.

珠肇高铁西江特大桥主桥总体设计

珠肇高铁西江特大桥主桥为(70+148+2×435+148+70)m三塔斜拉桥,采用中塔设置固定支座、边塔设置纵向活动支座的支座体系,在中、边塔处均设置纵向液压阻尼器,辅助墩、边墩处设置E型钢阻尼器,并设置2对中塔加强索以提高桥梁刚度。主梁采用钢-混组合梁,钢结构采用槽形截面,桥面板采用混凝土板,负弯矩较大的主梁区段采用顶、底板双组合截面以改善主梁应力状态。辅助墩两侧共58 m范围内钢结构与混凝土桥面板采用缓粘结剪力钉连接,桥面板采用超高性能混凝土(UHPC)+钢筋混凝土(RC)组合结构,以提高桥面板抗裂性能。采用H形桥塔,由上、中、下塔柱和上、下横梁组成,桥面以上塔高与主跨跨径比值为1/3.69,桥塔及桥墩均采用钻孔灌注桩基础;斜拉索采用双索面扇形布置,全桥设置102对平行钢丝拉索以及2对中塔加强索。该桥结构验算结果表明:桥梁具有合理的刚度、良好的轨道平顺性、气动稳定性及抗风性能,能够满足高速列车运行要求。

Study on low temperature performance of Gussasphalt on steel decks with hard bitumen

Using a Hamburg wheel-track test device, the resistance to rutting of Gussasphalt is tested and compared. Gussasphalt with hard bitumen has good resistance to rutting. The related resistance abilities to cracking at low temperature of Gussasphalt are tested and compared through flexural experiments and the composite structure fatigue test with temperature dropping. Gussasphalt with high performance polymer modified bitumen has a longer fatigue life and a lower breaking temperature; they can be used in the future surfaces for steel bridge decks in Germany.

配比设计中缺失数据的hot-deck估算

目的 探讨hot deck估算在含有缺失数据的配比设计资料分析中的应用。方法 在Stata7 0软件上利用AdrianMander和DavidClayton开发的hot deck程序进行数据模拟。 结果 hot deck估算可以使缺失数据所包含的信息得到一定程度的弥补 ,当含有缺失值的变量是分类或等级变量时 ,效果更为显著。结论 hot deck估算是解决配比设计资料中离散型数据缺失问题的一个有效工具。

基于XMCDA标准的DEXi模型在Decision Deck平台上的应用与实现

DEXi是一个面向教育的,组合约束条件的决策支持计算机软件,其目的在于交互设计定性的,组合约束条件和分层次的决策支持模型,以及对备选方案的评估。XMCDA是一个新出现的数据标准,它根据清晰定义的语法,支持用XML来呈现组合约束条件决策支持的数据元素。在这篇文章中,我们调查了一些方法,并且提出了一些将定性的DEXi决策支持模型转化为XMCDA标准的解决方案。这项工作的动机在于实现DEXi模型在Decision Deck这个使用组合约束条件决策支持的标准来协作开发开源软件的平台上的应用。

搁置脚载荷下滚装船甲板接触计算与实验分析

运输装置底部的搁置脚与滚装船甲板之间存在着复杂的非线性接触关系,不能简单地将搁置脚载荷视作均布载荷来处理。为探讨在搁置脚载荷作用下船舶甲板结构的接触压力与应力分布,以某钢质甲板结构为研究对象,采用Abaqus对其进行非线性接触数值计算,通过实尺度搁置脚载荷甲板强度实验,对搁置脚不同位置下甲板模型的接触压力、甲板板应力、纵骨应力进行分析,并将实验结果与仿真结果进行对比分析,验证搁置脚与甲板的接触压力分布规律,并在此基础上提出一种针对甲板板的简化计算方法,将复杂的非线性接触计算转变为较为简单的线弹性计算。结果表明,接触压力主要集中在搁置脚前端和横梁附近,以强横梁为代表的强构件是主要承载构件,甲板板高应力区域主要集中在搁置脚底部前端以及横梁附近,实验结果与数值计算结果吻合较好。本文计算模型具有较高的准确性,简化计算方法对滚装船甲板设计及强度计算具有较好的实用性。

450级大U肋正交异性组合桥面板静力力学性能

为了研究大U肋正交异性组合桥面板的静力力学性能,以U肋开口宽为450mm的正交异性钢桥面作为研究对象,引入超高性能混凝土,设计制作了两个足尺的大U肋正交异性超高性能混凝土组合桥面板,通过静力加载试验测试了大U肋正交异性组合桥面板的承载能力、破坏形态及主要截面上的应变;在此基础上,建立基于UHPC塑性损伤的有限元模型展开参数化分析。试验结果表明:大U肋正交异性组合桥面板的U肋厚度由8mm提升到10mm,屈服荷载与极限承载力提升了24.86%与47.48%,纯弯段混凝土裂缝数量减少,裂缝间距增大,加劲肋厚度的改变对于结构静力性能的影响主要体现在结构的非线性阶段。参数化分析结果表明:改变450级大U肋截面构造尺寸对结构屈曲变形能力有不同程度的影响,顶板厚度的改变对结构极限状态时的安全系数影响较小,提高U肋厚度可以大幅提高结构安全储备。依据试验结果与有限元分析提出了450级大U肋钢-UHPC组合桥面板的屈曲折减系数经验公式,该系数同U肋高厚比与U肋底板宽厚比更为相关。

新型钢-UHPC组合桥面连续构造性能研究

[目标]为了解决传统桥面连续构造易开裂、耐久性差的难题,充分发挥组合结构的受力特点及超高性能混凝土(UHPC)强度高、耐久性优异的力学性能优势。[方法]提出了钢-UHPC组合桥面连续构造形式。基于有限元法建立桥面系节段模型,分析了传统桥面连续构造的病害机理,对比了新型钢-UHPC组合桥面连续构造和传统桥面连续构造在设计车辆荷载及温度效应作用下的位移及应力响应。[数据]采用钢-UHPC组合桥面连续构造后,桥面连续处转角变得相对平缓,混凝土层最大拉应力从21.0 MPa大幅降低至7.6 MPa,且低于UHPC120材料的弯曲抗拉强度。[结论]分横梁的挠曲变形是桥面连续构造病害的主要原因之一,传统桥面连续构造在轮载作用下,连续缝处顶、底面拉应力较大,极易产生开裂病害。钢-UHPC组合桥面连续构造由于具有较高的弯曲变形能力,UHPC层拉应力能满足抗裂性能要求,且具有较高的强度储备,UHPC层与旧混凝土界面之间的抗剪强度满足规范要求。[应用]桥面连续构造维修完成并运营5 a后,现场实地勘查结果表明维修部位未产生任何病害,维修效果良好。钢-UHPC组合桥面连续构造简单合理、施工便利、无需完全中断交通、全寿命周期成本低廉、高效绿色,具有可观的市场应用前景及重要的社会、经济效益。

双层异质环氧沥青复合型桥面铺装SEC-DECK

SEC-DECK为东南大学提出的双层异质复合铺装结构,其铺装上层为沥青玛蹄脂碎石混合料,铺装下层为环氧沥青混合料,在国内二十多个钢桥中得到成功应用。系统介绍SEC-DECK的铺装结构组成、性能、设计建造关键技术及其在国内的应用状况,供国内同行桥面铺装设计参考。