高速公路桥梁拼宽设计及施工关键技术研究

以某高速公路桥梁拼宽工程为依托,通过收集既有桥梁拼宽的设计方案、施工技术等相关资料,对桥梁拼宽的设计原则、拼宽方式及施工关键技术进行探析,为同类工程提供借鉴和参考。     

预制结构桥梁拼接湿接缝受力性能分析及荷载试验

文章针对既有公路改扩建工程中预制结构桥梁拼宽问题,论述多种预制结构桥梁拼宽的连接形式,并采用梁板组合模型分析拼接处湿接缝的受力性能,结合荷载试验情况进行验证分析,为改扩建工程中预制结构桥梁的拼宽设计提供参考。     

旧桥拼宽设计分析

已建桥梁横向以拼接加宽的方式新建新的桥梁,最终形成整体桥面的桥梁设计方案。设计中的重点和难点是如何保证加宽后新旧桥梁结构受力均衡合理、沉降量少而协调、从而使拼宽后的桥梁结构具有良好运营性能。结合福州市永泰县南环东路(商贸物流园段)道路工程下林桥桥梁拼宽设计,探讨了旧桥拼宽设计要点。     

新增改造荷载的既有先简支后连续T梁桥承载能力评估

对一座拟改造加铺沥青及铺设管道的既有预应力混凝土先简支后连续T梁桥进行了结构检测,结合检查结果对桥梁承载能力进行检算,并对抗裂性进行了验算。通过基于检测结果的桥梁检算评定,判断桥梁是否满足拟新增道改造荷载的要求。相关方法可对同类桥梁承载能力评估具有借鉴参考意义。     

空心板桥拼宽后老桥承载力验算

随着交通量增大,高速公路改扩建项目的增多,高速公路逐渐进入拼宽时代。这里以郑州机场高速公路为背景,通过对老桥空心板拼宽方式的研究,计算拼宽后桥梁整体横向分布系数,并结合新规范设计荷载验算老桥承载力,为空心板拼宽及拼宽后运营养护提供参考和建议。     

高速公路桥梁拼宽改造关键问题分析

结合已有研究,针对高速公路桥梁拼宽中新建桥梁（以下称“新桥”）和既有桥梁（以下称“旧桥”）连接接缝类型的选择、拼宽桥梁受力状态变化的分析、不中断交通的施工工艺等问题,进行初步地总结和分析,指出了该领域存在的问题和今后主要的研究方向,对于高速公路桥梁的拼宽改造具有一定的参考价值。     

高速公路改扩建既有桥梁拼宽施工技术

现如今,一个国家发展的速度与公路桥梁建设之间的关系尤为紧密,为了可以显著提升人们生活质量和社会经济效益,高速公路改扩建工程也逐步增多。在我们国家经济建设脚步不断加快的形势之下,公路改扩建价加宽阶段之中针对既有桥梁拼宽施工技术已经成为施工单位需要关注到热点话题。鉴于此,本文结合京新高速(G7)新疆境内大黄山至乌鲁木齐段改扩建工程项目第四合同段桥梁拼宽施工,进行高速公路改扩建过程中预应力空心板桥梁拼宽施工中技术的论述,为后续桥梁拼宽提供建设性意见。     

桥梁加固改造设计技术研究

为解决既有钢筋混凝土刚构桥承载力不足及交通量饱和的问题,以罗田县巴源大桥为研究对象,采用有限元计算和检测技术方法,获得桥梁关键部位现有承载力,在此基础上运用增大截面法和粘贴钢板法对桥梁进行加固设计,并提出桥梁拼宽技术手段。实践结果表明,运用技术方法对桥梁进行加固和拼宽后,桥梁抗力明显提升,承载力、裂缝、跨中挠度等关键力学性能指标均满足规范要求,交通拥堵得到极大缓解。     

浅谈高速公路改扩建工程拼宽施工技术

以京哈高速公路为例,探讨高速公路改扩建工程拼宽施工技术,主要包括拼宽路基施工技术、拼宽桥梁施工技术和拼宽路面施工技术,最后对工程施工的方式进行总结。     

浅谈新旧桥梁拼宽施工技术及应用

交通运输业发展迅速,桥梁运输受到的压力不断增大,由于目前的交通需求,过去建成的桥梁很难满足。所以,桥梁需要重建,通常对其进行拼宽是比较常见的方式。本文对新旧桥梁拼宽施工技术及应用进行了探讨,希望能为业界同行提供参考。     

Improving the reliability of a Bridge Management System (BMS) using an ANN-based Backward Prediction Model (BPM)

The slow adoption of Bridge Management Systems (BMSs) and its impractical future prediction of the condition rating of bridges are attributed to the inconsistency between BMS inputs and bridge agencies' existing data for a BMS in terms of compatibility and the enormous number of bridge datasets that include historical structural information. Among these, historical bridge element condition ratings are some of the key pieces of information required for bridge asset prioritisation but in most cases only limited data is available.

This study addresses the abovementioned difficulties faced by bridge management agencies by using limited historical bridge inspection records to model time-series element-level data. This paper presents an Artificial Neural Network (ANN) based prediction model, called the Backward Prediction Model (BPM), for generating historical bridge condition ratings using limited bridge inspection records. The BPM employs historical non-bridge datasets such as traffic volumes, populations and climates, to establish correlations with existing bridge condition ratings from very limited bridge inspection records. The resulting model predicts the missing historical condition ratings of individual bridge elements. The outcome of this study can contribute to reducing the uncertainty in predicting future bridge condition ratings and so improve the reliability of various BMS analysis outcomes.     

Life-cycle reliability assessment of reinforced concrete bridges under multiple hazards

This paper proposes a novel probabilistic methodology for estimating the life-cycle reliability of existing reinforced concrete (RC) bridges under multiple hazards. The life-cycle reliability of an RC bridge pier under seismic and airborne chloride hazards is compared to that of a bridge girder under traffic and airborne chloride hazards. When conducting a life-cycle reliability assessment of existing RC bridges, observational data from inspections can provide the corrosion level in reinforcement steel. Random variables related with the prediction of time-variant steel weight loss can be updated based on the inspection results using Sequential Monte Carlo Simulation (SMCS). This paper presents a novel procedure for identifying the hazards that most threaten the structural safety of existing RC bridges, as well as the structural components with the lowest reliability when these bridges are exposed to multiple hazards. The proposed approach, using inspection results associated with steel weight loss, provides a rational reliability assessment framework that allows comparison between the life-cycle reliabilities of bridge components under multiple hazards, helping the prioritisation of maintenance actions. The effect of the number of inspection locations on the updated reliability is considered by incorporating the spatial steel corrosion distribution. An illustrative example is provided of applying the proposed life-cyle reliability assessment to a hypothetical RC bridge under multiple hazards.     

Drone-enabled bridge inspection methodology and application

The field of Civil Engineering has lately gained increasing interest in Unmanned Aerial Vehicles (UAV), commonly referred to as drones. Due to an increase of deteriorating bridges according to the report released by the American Society of Civil Engineers (ASCE), a more efficient and cost-effective alternative for bridge inspection is required. The goal of this paper was to analyze the effectiveness of drones as supplemental bridge inspection tools. In pursuit of this goal, the selected bridge for inspection was a three-span glued-laminated timber girder with a composite concrete deck located near the city of Keystone in the state of South Dakota (SD). A drone, a Dà-Jiāng Innovations (DJI) Phantom 4, was utilized for this study. Also, an extensive literature review to gain knowledge on current bridge inspection techniques using drones was conducted. The findings from the literature review served as the basis for the development of a five-stage drone-enabled bridge inspection methodology. A field inspection utilizing the drone was performed following the stages of the methodology, and the findings were compared to current historical inspection reports provided by the SD Department of Transportation (SDDOT). Quantified data using the drone such as a spalled area of 0.18 m², which is identical to the measurement provided by the SDDOT (0.3 m by 0.6 m), demonstrated the efficiency of the drone to inspect the bridge. This study detailed drone-enabled inspection principles and relevant considerations to obtain optimum data acquisition. The field investigation of the bridge demonstrated the image quality and damage identification capabilities of the drone to perform bridge inspection at a lower cost when compared to traditional methods.     

A simplified management procedure for bridge network maintenance

Structural problems due to corrosion, ageing, durability, aggressive environments, materials defects, lack of ductility and unforeseen behaviour under seismic loads may significantly compromise the resistance and safety of bridges. Scheduled maintenance of bridges becomes important to ensure complete serviceability of the road network. Among existing bridge management systems (BMSs), this work is a contribution to the evaluation criteria of bridge condition by means of visual inspection, prediction of future structural condition and planning of maintenance intervention. After a brief review of some existing BMSs, a simple new procedure for evaluation of bridge condition by means of visual inspection, aimed at general planning of maintenance in a BMS framework, is presented in this paper. This procedure is applied to stock, including about 200 bridges and viaducts, of the Veneto region road network in the north-eastern part of Italy, and is then discussed.     

基于无人飞机成像的桥梁裂缝宽度识别可行性研究

基于传统桥梁检测车裂缝宽度检测存在阻碍交通、受到桥型限制、使用维护费用高等问题。该文以旋翼无人飞机为工作平台,为满足0.2mm以上桥梁裂缝宽度识别要求,采用IMETRUM非接触式测量仪验证无人机悬停状态下机载成像质量具有可靠性;通过加装机载三点激光测距仪,测量物距并推导成像平面与被测平面夹角,计算并修正裂缝图像像素解析度;设计适于无人机成像的图像预处理程序、构建基于支持向量机（SVM）裂缝形态智能提取训练模型、裂缝法向实际宽度计算方法。以湘潭市湘江二大桥为研究对象,通过对实桥进行无人机裂缝宽度识别,并与传统人工测试进行比较,表明机载成像识别裂缝宽度满足工程精度要求,以无人飞机为工作平台替代桥检车或支架工作平台,实现结构表面裂缝形状与宽度识别具有可行性和广泛应用前景。     

市政道路桥梁工程材料质量检测控制优化策略

市政道路桥梁建筑工程材料的质量检测与交通运输安全、人民群众的生命安全息息相关.本研究从阐述道路桥梁工程材料的质量检测的研究意义出发,详细探讨市政路桥建筑工程材料质检中普遍存在的问题:材料检测设备的精度、取样的规范性、质检人员素质等突出问题,并提出道路桥梁工程材料质检的优化方案和策略.     

人工神经网络技术在桥梁检测评估中的应用

对现有桥梁的评估方法作了简要介绍,重点讨论了常用的BP人工神经网络模型,并将BP模型应用到桥梁结构检测评估中,指出人工神经网络在桥梁结构的检测评估方面一定有很好的发展前景.     

Inspection,condition evaluation and replacement of elastomeric bearings in road bridges

This paper presents the results of an inspection campaign as well as condition evaluation and replacement of more than 1000 elastomeric bridge bearings under service on the Isfahan state highway bridges constructed before 1990. It is the first comprehensive survey of this kind. The research was accomplished through inspection surveys, analysis of existing bridge maintenance data, condition evaluation and replacement of a significant portion of the inspected bearings and expert interviews. Inspection surveys and analysis of extracted data identified the problems and their causes and the merits and potential improvement of performance of each one of the inspected elastomeric bearings. Replacement of the damaged bearings with new ones was performed based on the results of this stage. The expert interviews investigated the practices of Isfahan and surrounding states regarding the selection of bearing manufacturers, the performance and the quality control of elastomeric bearings.     

Estimating bridge performance based on a matrix-driven fuzzy linear regression model

Determining a reliable bridge maintenance and rehabilitation strategy relies on accurate predictions of bridge conditions. Conventional regression cannot handle visual inspection results that are inherently non-crisp or linguistic. On the other hand, fuzzy regression provides an effective means for coping with such fuzzy data or linguistic variables. However, many of the existing fuzzy regression models require substantial computations due to complicated fuzzy arithmetic. This paper presents a multiple fuzzy linear regression using matrix algebra. The proposed model is capable of dealing with a mixture of fuzzy data and crisp data. Moreover, the approach is intuitive and easy to implement as compared to other related fuzzy regression models. A case study using bridge inspection data is presented to establish estimated fuzzy regression equations produced by the proposed approach and examine the factors contributing to overall bridge performance. The results demonstrate the capability of the approach, which can assist bridge managers to make better maintenance policies based on the future bridge conditions predicted by the model.     

石安高速路支漳河特大桥桥面铺装改造方案

根据支漳河特大桥的工程现状，调查分析了桥面铺装病害，在试验检测的基础上，总结了病害成因，提出了改造治理方案，经过治理后，桥面使用效果良好。