美景大桥施工控制仿真分析

指出美景大桥为大跨度预应力混凝土连续梁桥,以其为工程背景建立有限元模型,分析了悬臂施工中影响预拱度的各项因素,通过合理的计算和理论分析确定了桥梁施工过程中在受力和变形方面的工作状态,为类似桥梁工程的施工控制分析提供了参考。     

厦门海底隧道陆域浅埋段动态施工过程分析

基于地下工程施工力学理念,结合我国首条海底隧道--厦门翔安隧道工程陆域浅埋段施工过程,根据目前采取的CRD施工方法,建立数值模型,对其施工过程进行了模拟.分析了施工过程中随着各部的开挖,隧道变形动态发展历程;对浅埋隧道地表沉降采用经验预测和数值模拟进行了分析,数值计算结果反映了地表沉降随隧道各部开挖的动态变化过程;通过对初期支护时变受力体系分析,可以为施工过程中结构安全性评价提供依据;对开挖过程中隧道围岩应力状态和塑性区发展历程的分析,为洞室稳定性评价提供了理论依据.通过对大跨浅埋隧道在复杂地质条件下动态施工过程分析,可以进一步了解施工过程中围岩--支护系统相互作用的动态力学响应,为隧道动态设计与施工提供了科学的方法.     

金溪大桥施工监控仿真分析

以金溪大桥为背景,介绍了大跨度桥梁施工过程仿真分析的目的和意义,并建立了有限元模型,分析了悬臂施工中影响预拱度的各项因素,为类似结构桥梁的施工控制分析提供了参考。     

隧道的常规施工和管理

隧道施工是由多种作业工序构成,施工的综合性非常强.对隧道工程的施工管理中常规和普通的做法进行了分析和总结,为常规隧道的施工管理提供了一个思路,希望能够为隧道的施工和管理提供借鉴.     

技术经济分析方法在施工方案优选中的应用

介绍了施工方案技术经济分析的内容及其方法,将技术经济分析应用于具体工程中,通过对施工对象、方法的分析,以及对功能系数和成本系数的计算,体现了经济技术分析在实际施工方案中的经济价值,为今后施工方案的经济技术分析提供了参考。     

BIM技术在装配式建筑工程施工中的应用分析

建筑行业为了能够顺应时代发展的潮流,对装配式建筑工程施工项目进行了相应的改革和完善。为了提高建筑工程施工过程中信息数据的收集和传递效率,合理利用BIM技术加快信息的分析速度和分析效果,为施工过程中各环节的施工操作进行了监督和管控,确保施工前期方案制定、生产过程以及施工过程等的操作质量。本文分析了BIM装配式建筑工程施工过程中的应用方式和所起到的作用,从而提高建筑工程施工过程的智能性和环保性。     

路桥施工中机械的配置与优化管理研究

从路桥施工中施工机械配置和管理中存在的问题入手,分析了机械配置方法,提出了优化管理措施,可有效提高工程管理效果,为施工中合理配置施工机械,进行优化管理提供有力依据。     

凫洲大桥施工控制的仿真分析

随着大跨度桥梁的发展和建设,对施工过程的控制和仿真分析在实际工程中显得越来越重要.本文以凫洲大桥为工程背景,介绍了大跨度桥梁施工过程仿真分析的目的和意义,着重阐述了施工仿真分析中施工过程的模拟、参数的选取、预拱度以及立模标高的确定.     

房屋建筑混凝土施工技术标准探讨

本文首先介绍了房屋建筑混凝土施工的主要特点和构造要求,然后对施工中存在的主要问题进行了分析,最后就房屋建筑混凝土施工的主要技术要点进行了分析,以期为提高房屋建筑混凝土施工技术水平提供参考。     

市政给排水管道施工质量控制要点

结合海南陵水黎安建二路等市政项目,阐述了市政给排水管道施工的重要性,总结了施工中常见的问题,对给排水施工准备阶段、施工阶段、竣工验收阶段中的施工注意事项进行了分析.通过以上内容的研究,为该工程的施工提供了理论分析和施工技术指导.     

桥型象限图在构建协作体系桥梁中的研究

为推动协作体系桥梁的发展,本研究利用桥型象限图对多座现有协作体系实桥进行了构建验证,并通过桥型象限图构建出多种新的不同结构类型的协作体系桥梁。研究表明协作体系桥梁是以五类基本桥型为基础的复杂桥梁,基于桥型象限图能排列、组合出各种不同结构类型的协作体系桥梁。根据协作体系桥梁的特点,提出一类针对大跨度梁式桥跨中下挠病害的加固专用协作体系桥型方案。桥型象限图可为今后协作体系桥梁的设计与研究,提供一种简单快捷方法。     

Considerations on recent trends in, and future prospects of, steel bridge construction in Japan

In this paper, consideration is given on recent trends in, and requirements for a bright future of, steel bridge construction in Japan. As far as recent trends are concerned, it is observed that the construction of long and big steel bridges has practically been completed. Consequently, the focus of recent main works is the maintenance of superannuated (overaged) bridges and the seismic retrofitting of existing bridges. The refreshment and regeneration of some superannuated bridges is also needed recently in order to mitigate the uncomfortable influence of these bridges on their surrounding environment. As for a bright future in steel bridge construction, first and foremost it is emphasized that the steel bridge industry should be able to attract, train and retain better students and engineers. For this purpose, maintenance and retrofitting works should be economically reasonable jobs. The necessity and importance of these works should be understood by the nation through retrofitting existing bridges against disasters and mitigating the unfavourable influence of bridge structures on the bridge environment on the basis of the code of ethics for civil engineers promulgated by JSCE. Moreover, bridge engineers should seek better social status and the bridge engineering field should become attractive to young students who will bear the future of this field.     

Critical issues,condition assessment and monitoring of heavy movable structures: emphasis on movable bridges

In this paper, a relatively less studied class of structures is presented based on the research conducted on Florida's movable bridges over the last several years. Movable bridges consist of complex structural, mechanical and electrical systems that provide versatility to these bridges, but at the same time, create intermittent operational and maintenance challenges. Movable bridges have been designed and constructed for some time; however, there are fewer studies in the literature on movable bridges as compared to other bridge types. In addition, none of these studies provide a comprehensive documentation of issues related to the condition of movable bridge populations in conjunction with possible monitoring applications specific to these bridges. This paper characterises and documents these issues related to movable bridges considering both the mechanical and structural components. Considerations for designing a monitoring system for movable bridges are also presented based on inspection reports and expert opinions. The design and implementation of a monitoring system for a representative bascule bridge are presented along with long-term monitoring data. Various movable bridge characteristics such as opening/closing torque, bridge balance and friction are shown since these are critical for maintenance applications on mechanical components. Finally, the impact of environmental effects (such as wind and temperature) on bridge mechanical characteristics is demonstrated by analysing monitoring data for more than 1000 opening/closing events.     

跨越山谷高墩混凝土桥地震倒塌分析

高墩桥在中国西部多山谷地区得到广泛的应用,然而对其抗震性能的研究并不充分,我国尚没有确立相关的分析设计方法与规范,因此对其进行非线性地震响应分析乃至倒塌分析以便研究其地震破坏模式是十分有意义的。本文以贵州省高速公路上跨越山谷的某大桥为例进行了研究。该桥是一座处于典型西部地区山地、桥体为双向分离的曲线T型刚构高墩混凝土桥。本文在对全桥进行动力特性分析的基础上,采用有限元软件LS-DYNA进行了全桥非线性时程响应分析,考虑桥体的碰撞,得到塑性铰形成与发展状况以及破坏模式,实现了对全桥倒塌过程的仿真。本研究结果对类似桥梁的抗震设计提供了有益的参考。     

关于桥梁几个概念的探讨

本文用简洁的语言表达了桥梁的一些最基本的概念 ,如 :桥梁的定义、桥梁的型式、影响桥梁发展的三大要素、桥梁的力学概念以及梁桥、拱桥、索桥的共性和特性等 ,通过对这些基本概念的探讨 ,融会贯通 ,可对桥梁有更深入的理解 ,有助于桥梁的概念设计     

A probabilistic assessment for classification of bridges against fire hazard

This paper presents the development of a simplified approach for classification of bridges based on fire hazard. Statistical data from recent fires in bridges is utilized to quantify the probable risk of fire in bridges and also probability of fire-induced collapse of structural members in bridges. An importance factor is derived for identifying the vulnerability of bridges to fire hazard. The proposed importance factor, developed using weighted factor approach, takes into account the degree of vulnerability of different bridge components, critical nature of a bridge from traffic functionality point and fire mitigation strategies present in a specific bridge. The proposed importance factor for fire design, which is similar to the one currently used for evaluating wind, and snow loading in buildings, is validated against previous bridge fire incidents. It is shown through this validation that the proposed method for importance factor can be used as a practical tool for identifying critical bridges from the point of fire hazard.     

A risk ranking strategy for network level bridge management

This paper presents the development of a qualitative risk ranking strategy for characterising a network of bridges into groups with similar risk levels, which can form the basis for developing a risk based inspection regime over a bridge network. The factors affecting risk are identified and rationally combined to present various attributes of bridges. A qualitative scoring system is then introduced that uses the attributes to rank bridges in terms of their relative risk. Sensitivity analysis is performed to quantify the effect of relative weights of the attributes on the risk scores. The methodology is demonstrated through its application on the UK's Network Rail bridge stock and a random sample of bridges is ranked according to the proposed method. One of the factors used to evaluate the risk scores is comparable with the bridge condition index. A reasonable agreement between them is observed within the sample bridges. The proposed method will be beneficial to bridge owners in identifying the bridges according to their risk levels in a simple and systematic manner. Inspections and interventions can be planned based on this risk ranking strategy to maintain a consistent risk level across the network.     

Numerical study on post-fracture redundancy of the two-girder steel-concrete composite highway bridges

As the Japan bridge inventory ages and traffic volumes increase, the government is spending more on maintaining their existing structures to extend the service life of the current bridge inventory. This includes two-girder bridges that are classified as fracture critical and non-redundant. Owing to the increased inspection costs associated with these fracture-critical bridges, there is a need to evaluate alternate load paths and to implement retrofit methods on existing bridge structures to avoid bridge replacement. In this paper, fracture redundancy of the two-girder bridge is investigated through a case study for a three-span continuous twin I-girder bridge. The finite element analysis is carried out to evaluate the load-carrying capacity after fracture of a girder of the two-girder bridge. Damage of studs near the moment contra-flexure regions are also considered in this study. Spacing between the transverse beams is discussed as possible techniques to improve redundancy and reduce the fracture potential of two-girder bridge structures. The concrete slab is indicated to be a significant member for guarantying the redundancy of the two-girder steel-concrete composite bridges.     

混合式桥型对超长跨桥梁的适应性

本文对中跨为2500m的混合型斜拉悬索桥的进行了初步设计,构想了三种斜拉悬索桥和一种悬索桥桥式。从初步设计结果中比较它们上部结构钢材的重量发现,考虑到下部结构尺寸,斜拉悬索桥相对悬索桥具有优越性。另外,对这几种型式的桥梁进行了抗弯稳定性分析以及耦合颤振分析。分析结果表明,斜拉悬索桥抗弯稳定性是足够的,而且其临界风速高于悬索桥的临界风速。所以,作者认为针对超长跨度桥梁混合型斜拉悬索桥赛过悬索桥