单拱面预应力混凝土系杆拱梁桥极限承载力分析的截面内力塑性系数法

基于UpdatedLagrangian (更新拉格朗日 )列式单元增量平衡方程 ,提出了一种建立钢筋混凝土空间梁单元弹塑性刚度矩阵的新方法———单元节点截面内力塑性系数法 ,并编制了单拱面预应力混凝土系杆拱梁桥空间稳定极限承载力计算程序。理论分析结果与两个模型试验结果十分接近 ,验证了分析方法的正确性及可靠性。该方法可以用于大型桥梁的空间稳定极限承载力分析     

行波效应下铁路简支梁桥梁轨系统地震响应

基于多点激励的大质量法,采用非线性杆单元模拟梁轨接触,建立了考虑地震动行波效应的简支梁桥梁轨相互作用模型。以沪昆线上某5-32m简支梁桥为算例,分析了行波效应作用下轨道结构对桥梁地震响应的影响,研究了行波效应下钢轨和墩台的受力特性,并对相关参数的影响做了探讨。研究表明：行波效应下轨道结构将大大增强梁体和下部结构的地震响应;轨道对行波效应极为敏感,视波速越低轨道和墩台受力越大;支座布置形式和桥墩刚度突变对相邻桥墩受力影响显著;随着简支梁跨数的增加,钢轨和桥台受力逐渐增大并趋近于一定值。     

关于高速铁路中小跨度桥梁设计活载模式的探讨

桥梁活载设计标准是桥梁设计的主要依据和控制因素。基于对目前世界各国高速铁路上运行的典型车辆和采用的活载标准的深入研究,针对我国高速铁路桥梁常见的结构形式,对常用中小跨度简支梁、连续梁在现行运营车辆荷载和多种标准设计活载下的结构响应进行了比较分析。分析结果表明,采用我国现有的活载设计标准指导设计,中小跨度桥梁结构偏于安全,但安全储备量过大,有必要进行适当优化。综合考虑安全性及经济性,建议采用0.6UIC活载作为高速铁路客运专线中小跨度桥梁设计活载,采用UIC活载作为高速铁路客货共线中小跨度桥梁的设计活载。     

纯滚动隔震系统位移计算方法的对比分析

针对纯滚动隔震系统,根据其地震位移反应规律,编制了数值分析程序;采用实验方法和理论分析方法,对比分析了数值分析程序和传统的刚塑性力-位移曲线方法.结果表明,数值分析程序比较合理,计算结果比较精确,且偏于保守;传统的刚塑性力-位移曲线方法不合理,计算结果偏小;地震作用下,结构的最大相对位移可能超越地面的最大绝对位移.     

纯滚动隔震系统位移计算方法的对比分析

针对纯滚动隔震系统,根据其地震位移反应规律,编制了数值分析程序;采用实验方法和理论分析方法,对比分析了数值分析程序和传统的刚塑性力位移曲线方法。结果表明,数值分析程序比较合理,计算结果比较精确,且偏于保守;传统的刚塑性力位移曲线方法不合理,计算结果偏小;地震作用下,结构的最大相对位移可能超越地面的最大绝对位移。     

Beam-track interaction of high-speed railway bridge with ballast track

Based on the construction bridge of Xiamen-Shenzhen high-speed railway (9–32 m simply-supported beam + 6×32 m continuous beam), the pier-beam-track finite element model, where the continuous beam of the ballast track and simply-supported beam are combined with each other, was established. The laws of the track stress, the pier longitudinal stress and the beam-track relative displacement were analyzed. The results show that reducing the longitudinal resistance can effectively reduce the track stress and the pier stress of the continuous beam, and increase the beam-track relative displacement. Increasing the rigid pier stiffness of continuous beam can reduce the track braking stress, increase the pier longitudinal stress and reduce the beam-track relative displacement. Increasing the rigid pier stiffness of simply-supported beam can reduce the track braking stress, the rigid pier longitudinal stress and the beam-track relative displacement.     

Sensitive factors research for track-bridge interaction of Long-span X-style steel-box arch bridge on high-speed railway

X-style arch bridge on high-speed railways （HSR） is one kind of complicated long-span structure, and the track-bridge interaction is essential to ensure the safety and smoothness of HSR. Taking an X-style steel-box arch bridge with a main span of 450 m on HSR under construction for example, a new integrative mechanic model of rail-stringer-cross beam-suspender- pier-foundation coupling system was established, adopting the nonlinear spring element simulating the longitudinal resistance between track and bridge. The transmission law of continuous welded rail （CWR） on the X-style arch bridge was researched, and comparative study was carried out to discuss the influence of several sensitive factors, such as the temperature load case, the longitudinal resistance model, the scheme of longitudinal restraint conditions, the introverted inclination of arch rib, the stiffness of pier and abutment and the location of the rail expansion device. Calculating results indicate that the longitudinal resistance has a significant impact upon the longitudinal forces of CWR on this kind of bridge, while the arch rib＇s inclination has little effect. Besides, temperature variation of arch ribs and suspenders should be taken into account in the calculation. Selecting the restraint system without longitudinally-fixed bearing and setting the rail expansion devices on both ends are more reasonable.     

压旋喷桩施工技术在高速铁路路基上的应用高

本文通过武广高速客运专线高压旋喷桩软土地基加固处理的施工经验,浅谈高压旋喷桩应用于高速铁路软基处理的施工工艺、质量控制和检测。     

移动模架线形控制在杨家坳特大桥中的应用

移动模架连续梁施工中,影响梁体线形的因素很多,本文结合杨家坳特大桥移动模架的施工实践,分析了移动模架系统施工过程中线形控制的要点。