装配式铰接板桥的铰缝损伤评价

针对装配式铰接板桥铰缝损伤程度评定方法不足的问题,为客观评定铰缝的损伤程度,并为铰缝的加固改造提供依据,基于装配式铰接板桥的试验数据及理论分析,通过引入铰缝损伤度λ与铰缝协同工作系数δ概念,建立铰缝损伤度λ与铰缝协同工作系数δ的关系模型及铰缝损伤度λ与铰缝实际抗力Z的关系模型,对装配式铰接板桥铰缝损伤评价方法、评价指标及承载能力加固的判定标准进行研究,并将研究结果应用于某5孔20m装配式预应力混凝土简支空心板桥的铰缝损伤评价中。结果表明:该损伤评定方法是可行的;计算的铰缝协同工作系数δ与实桥实测值接近,最大误差为2.3%。建议根据铰缝损伤的3个阶段进行相应的维修或加固。     

不中断交通的桥梁试验方法初探

桥梁试验是检验桥梁结构实际工作状态,保证桥梁安全运营的重要手段.经过不断的探索和实践,桥梁荷载试验技术得到较大发展和普及,试验方法也日趋成熟并形成了行业规范.然而,随着荷载试验方法在桥梁上的大量采用,其方法本身存在的问题和局限就越来越显现出来.关于桥梁荷载试验方法存在的诸多问题另文论述,本文就桥梁荷载试验需要中断交通,而实际又难以实现时,对作者提出和采用的不中断交通的桥梁试验新方法进行较全面的介绍和论述,并结合实桥试验进行分析探讨,以供同行研讨和参考.     

浅铰宽幅空心板桥横向加固技术研究

针对宽幅空心板浅铰铰的天生缺陷,制定了在桥跨四分点断面施加钢横梁及体外预应力的横向加固措施。试验证明两种加固方法非常适宜,对增加宽幅空心板的横向整体性能、抑制单板受力现象的发生起到了良好的作用。     

不中断交通情况下的高速公路空心板拼接质量控制

从桥梁拼接方式的选择、空心板梁拼接方案比选、不中断交通的纵缝施工工艺等方面介绍空心板拼接质量控制措施,对于高速公路桥梁拓宽工程中的空心板拼接具有一定的参考价值.     

横向体外预应力在空心板桥加固中的应用研究

药湖大桥系江南最长的高架桥之一,总长9100m,上部结构均为标准跨径20m预应力混凝土宽幅空心板(单板宽1.55m)。经过10余年的运营使用,发现该桥存在铰缝破损较为严重且单板受力现象明显、空心板跨中反拱值偏大等结构性病害。本文通过对体外横向预应力加固该桥的机理进行了分析,并通过实桥静载试验对加固效果进行验证。计算与试验结果均表明,体外横向预应力加固空心板桥效果良好。     

基于损伤分析的空心板桥荷载横向分布系数研究

既有空心板桥服役过程中,由于受到车辆荷载和外部环境的侵蚀作用,其上部结构不同部位会发生程度不一的损伤,梁体裂缝会导致主梁整体刚度退化,铰缝开裂损坏会导致传力削减.文中综合考虑梁体和铰缝均发生损伤情况,对桥梁损伤进行量化评估,在传统理论方法的基础上,引入主梁刚度损伤系数和铰缝传力削减系数,推导适用于发生损伤空心板桥的修正...     

不中断交通情况下的高速公路T梁拼接质量控制

从桥梁拼接方式的选择、T梁拼接方案比选、不中断交通的纵缝施工工艺等方面介绍T梁拼接质量控制措施。     

临川市上顿渡大桥加固方案的研究与实施

５０年代￣６０年代采用苏联无横隔板Ｔ形梁桥较多，现均难以满足交通要求，大多数桥梁都面临加固提载。在总结国内外桥梁加固提载经验的基础上，提出了一种体外预应力钢结构加固提载方案，使上顿渡大桥设计荷载由汽－１３、拖－６０，提高到汽－２０，挂－１００荷载标准。这样，既节省养护经费，又使老桥焕发青春，寻求了一种经济，简便，效果好的加固方法。     

体外预应力在空心板简支梁桥加固中的应用

以一座有代表性的旧预应力空心板简支梁桥为例,采用体外预应力钢绞线对该桥进行横向加固。通过加固前后汽车静载试验结果的比较,分析加固前后挠度的变化,证明了加固方法是有效的。     

碳纤维在旧桥加固中的应用

以内蒙古通辽市畅通桥加固为例,介绍了碳纤维增强复合材料（CFRP）技术的补强、加固原理、材料的性能、工艺流程及操作要求。该材料可延长桥梁的使用寿命,减少资金投入,在桥梁混凝土结构粘贴加固工程中值得推广应用。     

新型铰缝在重载交通道路桥梁设计中的应用

如何避免重载交通道路桥梁的铰缝早期损坏问题,是我们设计部门急于解决的问题。文章针对铰缝的设计进行研究,提出了防止铰缝早期损坏的有效办法。     

Education influence in traffic safety: A case study in Vietnam

It is well known that traffic accidents are of high importance to the public health spectrum around the world. Moreover, in developing countries such as Vietnam, the mortality rate from road traffic accidents is rather high in comparison with other Southeast Asian countries. Not only do the majority of the people killed and seriously injured significantly affect the quality of life of the citizens, but traffic accidents also negatively impact a nation's economic and social development. Statistics show that far more people are injured or die in traffic accidents than are afflicted by any of the most serious diseases. The very high occurrence of traffic accidents in Vietnam has become one of the country's major social issues. The importance of human factors in transport policy discussion is growing. There is a realization that policy options that appear beneficial in principle have to be checked for their feasibility of implementation. Understanding and describing driver behavior become a challenge when one tries to identify driver errors in determining accident/conflict causal factors and countermeasures.In recent years, having understood the serious effects of traffic accidents on society at large, scientific researchers, traffic engineers and policy makers in Vietnam have developed many projects and conducted research in the field of traffic safety. The human factor is also considered to be the central element in the whole system. The final goal is to organize a traffic environment that is convenient and safe for road users.This article explains the application of the risk analysis approach in evaluating influences of education and enforcement in traffic safety.     

Modelling traffic safety at uncontrolled median openings: A case study in India

Assessment of traffic safety is an essential study in transportation engineering. In a developing country like India, around 150,000 people die in road crashes every year. Furthermore, at uncontrolled median openings, the severity of road crashes is higher due to the presence of impatient U-turning road users who don't obey the rule of priority. Traditionally, road crash data have been used since long to analyze traffic safety. However, in developing countries, the main drawback of this conventional method is limited availability of accident data as very few accidents get reported. Moreover, the accuracy of these reported data is questionable. Therefore, now-a-days, various surrogate traffic safety measures like Post Encroachment Time (PET), and Time to Collision (TTC) are being used to examine the safety of road users. Among them, PET is regarded as the most consistent, and most widely used safety indicator. Therefore, in the present study, PET across different traffic volume levels has been determined. Videography data has been collected from selected median openings located on six-lane divided urban roads. PET values for different traffic volumes, and different category of vehicles have been analysed in detail. Further, the distribution of PET values across the full width of road has also been studied. Concept of critical speed is introduced which is compared with conflicting speed to assess unsafe conflicts and determine a critical PET. Finally, regression models have also been proposed with good levels of accuracy to determine the PET values for various category of vehicles travelling at different conflicting speeds.     

山岭重丘区公路20m以下空心板梁集中预制安装的利与弊

建设项目不仅要满足使用功能,其经济评价、社会评价、环境评价（环境污染、周边生态平衡、国民经济效益）、综合评价等也是功能评价的重要指标。文章针对工程实例,并根据价值工程理论,对山岭重丘区公路20 m以下空心板梁采用＂集中预制安装＂方案的可行性、成本、效果总评价方面进行了分析。     

超重交通对道路破坏作用及对轴重限值的探讨

根据天津市津围公路结构与交通现状，分析了超重轴载对常规道路结构实用性能与寿命的影响，在应力与弯沉分析的基础上，提出实行限载130kN在技术与经济上的可能性。     

城市交通噪声分析及其系统研究

利用流体力学与噪声理论建立了交通流和交通噪声数学模型.根据路段实际情况,在一维交通流的交通状态下,通过数值模拟与实测结果比较,实现了动态交通模拟,其模拟结果基本符合现实的交通噪声状况.从而解决了从交通流模型到噪声计算的顺利转接,为交通规划、城市建设、政府决策等方面提供了理论依据.     

宁波招宝山大桥主桥主梁重建加固施工

介绍宁波招宝山大桥主梁加固施工技术、措施及有关工艺试验。     

先简支后连续装配式板桥施工中硫磺砂浆复合支座的应用研究

临时支座的制作与拆除是先简支后连续装配式板桥施工的一个重要环节。文章介绍硫磺砂浆支座制作临时支座的试验情况、制作工艺及其应用。