浅谈震后桥梁的维修加固

发生地震后,保证受灾地区交通畅通是重中之重,而灾区沿线受损重点桥梁的维修加固更是首要任务。文章根据新疆2011年8月喀什地区伽师县发生里氏5.8级地震后某公铁立交桥的维修加固实例,对受损桥梁的快速维修加固和桥梁抗震设计提出一些建议,以供参考。     

大跨长联预应力混凝土连续梁桥地震反应分析

近年来,全球地震频发,而桥梁作为生命线工程,一旦在地震中发生破坏,将会给人民的生命财产及抗震救灾造成巨大的影响.大跨度预应力混凝土连续梁桥是最广泛应用的桥型之一,对其抗震性能进行深入的研究分析,是确保其良好安全性的重要内容.本文以托克托准格尔黄河特大桥为例,进行了地震反应谱分析和时程分析,分析时,考虑桩-土-结构相互作用以及滑动支座摩擦力对桥梁地震反应的影响.研究结果表明:①桩-土-结构相互作用减小了制动墩的内力,增大了其位移.②滑动支座摩擦力减小了桥梁的纵向地震反应,但对桥梁横向地震反应没有影响.③行波效应减小了制动墩的纵向地震反应,增大了其它桥墩的纵向地震反应,但对桥梁横向地震反应没有影响.     

地震作用下混凝土梁桥连续倒塌过程分析

在地震中发生落梁可导致梁桥连续倒塌破坏.探究地震作用下混凝土梁桥连续倒塌的机理和规律,对于桥梁抗震设计与抗震加固、避免地震中桥梁倒塌破坏有着重要的意义.采用最新的材料本构、合理的结构数值模型及结构碰撞模型,利用有限元软件ABAQUS分析了一座四跨连续梁桥.分析结果很好地模拟了这座梁桥在地震作用下发生连续倒塌的全过程,落梁导致邻近桥墩破坏,其余桥墩及梁跨结构倾斜,引起远端落梁,桥墩接连破坏,最终桥梁全部倒塌.分析结果显示桥墩底部和中部系梁连接处的破坏较严重,应该进行针对性的抗震设计或加固.     

浅析桥梁的震害现象及抗震设计

研究地震时桥梁结构的破坏现象,提出改进桥梁设计和施工方法。对降低地震造成的桥梁破坏、确保生命线工程的安全畅通以及抗震救灾有着极为重要的现实意义。     

钢筋混凝土刚架拱桥的震后加固设计与施工

位于四川省彭州市境内的川西大桥为8×45m的钢筋混凝土刚架拱桥,2008年5月12日,汶川发生里氏8.0级地震,带来了严重的震害,该桥也遭受一定程度的损坏。本文结合该桥的震后维修加固设计施工全过程,详细介绍了该钢筋混凝土刚架拱桥遭遇地震作用后的主要震害现象、通过结构有限元分析结果对病害原因进行了分析,制定了震损后快速修复的加固设计方案以及相应的加固施工技术,可供同类结构桥梁的震后快速加固修复或病害加固参考借鉴。     

砖墙体加固抗震性能的试验比较

通过对 4种不同砌体结构试验体的抗震试验 ,对得到的试验结果进行了比较。在无加固状态下的砖墙和用4水平筋加固的砖墙在水平荷载作用下其抗震性能很差。而用六角形镀锌铁丝网加固的砖墙 ,在粉刷水泥砂浆之后 ,其抗震性能明显提高。尤其是无加固砖墙体在试验中剪切破坏后 ,再用镀锌铁丝网加固后做粉刷 ,其抗震性能在试验初期明显提高。这对抗震救灾中的受地震作用破坏后的墙体加固提供了一种简便可行的方法。     

高原铁军情满三江源头——青海住房和城乡建设系统抗震救灾、恢复重建一线纪事

两年前的四川地震,青海省派出的青海省抗震救灾工程救援队载誉而归,被誉为"高原铁军".两年后,当玉树"4.14"特大地震发生的第一时间,这支铁军再度披甲,迅速奔赴灾区开展抗震救灾工作.十一天的抗震救灾中,省住房和城乡建设系统工程救援队全体队员发扬艰苦奋战、以苦为乐的精神,全力奋战在抗震救灾的第一线,被中华全国总工会授予全国"工人先锋号"光荣称号.     

甘肃积石山6.2级地震应急救援及启示思考

<正>2023年12月18日23时59分,甘肃临夏州积石山县发生6.2级地震,震源深度10公里。地震发生后,党中央国务院高度重视,习近平总书记作出重要指示,李强总理作出批示。副总理张国清率国务院工作组紧急赶赴甘肃、青海地震灾区指导抗震救灾工作。国务院抗震救灾指挥部、应急管理部将国家地震应急响应提升至二级,各成员单位快速响应,积极主动指导协助甘肃、青海开展抗震救灾各项工作。甘肃、青海两省启动地震二级应急响应,集结力量资源投入抗震救灾。     

桥梁结构在地震作用下经济损失预计方法研究

以基于性能的地震工程学理论为基础,运用增量动态分析方法,对桥梁结构在地震作用下的响应、破坏状态等进行分析,从而对桥梁结构的地震经济损失进行合理预计,为桥梁抗震设计、加固和维修提供重要依据。     

地震灾害下的桥梁网络可靠性分析

与单个桥梁的抗震评估相比,桥梁网络的地震评估通常涉及网络的优先次序,它总是涉及如何将有限的财力、物力和人力资源以最佳方式分配到桥梁的养护、维修和重建上。对意大利特伦蒂诺省的桥梁管理系统进行了抗震分析,定义了网络中任意两点的连通可靠性,并且利用网络状态列举算法进行了计算。计算结果通过GIS技术显示给用户。成果有助于桥梁管理人员和政府官员了解桥梁网络状态,并且可以帮助他们在地震发生后,迅速地作出合理有效的抗震救灾决策。     

Incorporation of Seismic Considerations in Bridge Management Systems

The objective of this paper is to incorporate seismic hazard and risk analysis considerations, which are concerned with the occurrence of earthquakes and the vulnerability of structures, into bridge management systems. We develop a decision model for optimizing bridge maintenance, repair, and reconstruction (MR&R) policies that takes into account the occurrence of earthquake events. The model presented in this paper is not meant to be very detailed or comprehensive, but rather to allow us to obtain qualitative implications of including seismic considerations in bridge management systems. Based on four different case studies, we found that accounting for the probability of earthquake occurrence in a bridge MR&R decision-making model had a significant impact on the probability distribution of the bridge condition state, the optimal policies, and their total cost. Furthermore, we found that ignoring the probability of destruction due to earthquakes would lead to errors in budgeting.     

采用强化弹塑性模型的钢筋混凝土结构抗震性能设计谱方法

建筑结构的常规抗震设计,是按多遇地震作用对结构进行承载力及弹性侧移计算。为了保证结构的抗震性能,须验算结构在设防地震及罕遇地震作用下的承载力及弹塑性侧移。本文采用振型分解反应谱法,其中等效单自由度体系采用强化弹塑性模型,模型主要参数由常规抗震设计确定,屈服后刚度及阻尼比按模型强化段进行调整,利用规范的地震反应谱,进行结构的弹塑性反应分析。二层钢筋混凝土框架结构算例计算结果表明,采用本文提出的设计谱方法与弹塑性时程分析方法的计算结果基本相当,而计算则大为简化。按本文方法所得设防地震及罕遇地震作用下的结构地震响应可用于结构承载力验算,所得侧移可用于结构侧移控制及变形能力设计。     

关于土耳其和台湾大地震的一点思考

本文对土耳其和台湾大地震的成因和造成的损失进行了分析和总结 ,了解到设计合理性和施工质量对结构抗震性能的重要性。同时讨论了地震发生后抗震救灾的经验和教训 ,对今后的抗震减灾有一定的借鉴作用     

Reliability-based capacity design for reinforced concrete bridge structures

In the seismic design of reinforced concrete (RC) bridge structures, there should be no brittle failures, such as shear failures, in the components, and a plastic hinge should be formed at the bottom of the bridge pier. These are important concepts in capacity design to guarantee the safety of bridges subjected to severe earthquakes. These concepts can maximise post-event operability and minimise the cost of repairing bridges after a severe earthquake. In this article, a reliability-based methodology to carry out capacity design with partial factors is proposed and applied to the seismic design of RC bridge structures. This ensures that (i) all of the components undergo the desired ductile failure mode, (ii) the damage due to an earthquake is induced only at the bottom of the bridge pier and (iii) the probability of failure is at most equal to a specified value.     

砌体结构TMD减震体系非线性地震反应研究

根据随机振动理论推导了多层剪切型结构TMD减震系统的随机地震响应,分析了参数的变化对TMD减振系统减震效果的影响,从而优化了取得最佳减震效果所需要的关键参数.以砖砌体结构为研究对象,建立了用于非线性地震反应的三线型骨架曲线及其滞回规律,编制了非线性地震反应分析程序,计算了一幢六层砌体结构减震前和采用TMD减震后的地震反应,分析结果表明,在7度多遇烈度和7度基本烈度地震动作用下减震效果良好,在7度罕遇烈度地震动作用下,TMD系统应通过加强构造措施保证抗震性能.     

钢筋混凝土桥墩延性分析与抗震能力评估

以中震为切入点,对桥墩地震需求与抗弯能力计算进行了研究,并结合算例进行了分析,结果表明：根据桥墩中震需求能力比确定合理的桥墩截面和配筋率,可以保证大震激励下桥墩核心混凝土不破碎。     

横向随机地震下震致轨道几何不平顺的功率谱密度曲线研究

为了保证高速铁路系统在抗震救灾期间能够继续运营以实现运送救援物资、医疗力量,有必要对震致轨道几何不平顺进行合理的预测。该文以高速铁路CRTS Ⅱ型轨道-桥梁系统为对象建立了有限元模型,从PEER强震数据库中筛选出60条具有随机特征的地震波并对有限元模型开展了非线性时程分析,研究了地震轨道残余不平顺的分布规律,提出了一种构造震致轨道几何不平顺功率谱密度曲线的方法,生成了震致轨道几何不平顺样本,探讨了震后轨道不平顺的模拟方法。研究结果表明：在横向地震后轨道发生了明显的轨向、高低、水平不平顺,轨距不平顺的幅值较小;轨道的地震随机残余不平顺在各个频率的功率谱密度服从对数正态分布;震致轨道几何不平顺谱可通过地震轨道残余不平顺谱集的均值和方差简单表示;初始不平顺对震致不平顺的影响作用可以忽略不计,震后轨道几何不平顺可以近似视为初始不平顺和震致不平顺之和。     

Recent research development and their applications on aseismic reinforcement of existing railway earth structures

In Japan, most of the existing railway earth structures were constructed before the development of the technical standards for design and construction. This suggests the risk of major deformation or failure during a massive earthquake is significant. Therefore, seismic diagnosis and aseismic reinforcement are required to ensure safety and resilience against massive earthquakes. The aseismic reinforcement of existing railway earth structures, such as embankments, cuts, retaining walls and bridge abutment, to prevent damage from massive earthquakes has been underway since around 2010. It is necessary to develop an aseismic reinforcement methodology since the ratio of earth structures in the existing railways exceeds 80 percent. Therefore, the Railway Technical Research Institute has been developing aseismic reinforcement methods together with cooperating organizations. This paper is an overview of the research and development of aseismic reinforcement methods of the existing railway earth structures, examples of their practical application, and future research issues.     

桥梁结构震害及抗震设计理念浅议

通过历次地震的震害调查,指出桥梁结构等生命线工程的损坏对救灾行动以及灾后恢复均有极大的影响,总结了桥梁震害的各类情况,对现有的抗震设计理念进行了论述,以期指导桥梁结构抗震设计工作。     

Investigation on dynamic behaviour of a full-scale reinforced concrete bridge subjected to strong earthquakes using an automated analysis platform

In this paper, the condition of a full-scale concrete bridge subjected to strong earthquakes is evaluated using vibration-based analyses. A new computational toolkit is developed in MATLAB environment for damage identification and long-term monitoring. Two types of parametric and non-parametric analysis methods are carried out on monitoring data. Moreover, a dynamic performance index is proposed based on an AutoRegressive Moving Average with eXogenous excitation (ARMAX) model. This index utilises the response predicted from an ARMAX model to evaluate bridge behaviour during strong earthquakes. Based on the results, a minor but permanent drop of 0.05?Hz in natural frequency of the first transverse and vertical modes is observed after the first strong earthquake. Also, a significant drop in frequency of the first transverse mode is observed during the two strong earthquakes. The results of the index show that the bridge did not follow linear behaviour during the two strong earthquakes as expected from a linear system. A close to flag-shaped force-displacement relationship is also observed during the first strong earthquake that can be an indication of nonlinearity in bridge behaviour. The analysis results illustrate the efficiency of the new monitoring platform for long-term monitoring and management of large datasets.