克拉玛依市2号人行天桥设计

为体现克拉玛依河改造工程的现代化景观效果，从城市、交通、和谐、景观入手，介绍克拉玛依河2号人行天桥的景观造型与结构设计，提出了该天桥的设计原则，指出该桥设计以充分发挥投资效益为前提，设计经济可行。     

Structural health monitoring of innovative bridge decks

For more than a century, important civil engineering structures such as bridges, high-rise buildings, dams and marine platforms have contained iron or steel as the reinforcement for concrete or wood. The useful lives of such structures have often been severely limited by the corrosion of this ferrous component. Much thought has been given in recent years to constructing structures that are lighter, stronger and non-corrosive. These innovative structures are new and for these to be accepted by the engineering community monitoring is mandatory. ISIS Canada has been developing such structures and monitoring them. In this paper, innovative bridge decks that have been implemented are described.     

Optimal intervention strategies for multiple objects affected by manifest and latent deterioration processes

In the existing infrastructure management systems, optimal interventions strategies (OISs) are determined for objects that deteriorate gradually (manifest deterioration process, MDPs), under the assumption that with appropriate inspection and intervention strategies the probability of failure of object can be neglected. Objects that deteriorate suddenly (latent deterioration process, LDPs), for example, due to scouring during a flood or earth movements during an earthquake are not considered. The determination of OISs for an object that deteriorates due to both MDPs and LDPs requires the consideration of both. The latter, however, means that the probability of failure of the object must be considered. In this article, a Markov model is presented that can be used to determine OISs for multiple objects of multiple types affected by uncorrelated MDPs and LDPs. The model is an extension of the model proposed by Mayet and Madanat (Incorporation of seismic considerations in bridge management systems. Computer-Aided Civil and Infrastructure Engineering, 17:185–193, 2002). In the model, a set of condition states (CSs) is used to describe the condition of objects of each type, where each set is composed of non-failure CSs and failure CSs. The probabilities of going from each non-failure CS to each failure CS are estimated using normalised fragility curves, and the probabilities of going from each non-failure CS to each non-failure CS are initially estimated using the Markov deterioration prediction model of Kobayashi, Kaito, and Lethanh (A Bayesian estimation method to improve deterioration prediction for infrastructure system with Markov chain model. International Journal of Architecture, Engineering and Construction, 1:1–13, 2012a) and later adjusted taking into consideration the probabilities of entering the failure CSs. The use of the model is demonstrated using a road link comprising one road section and one bridge.     

大桥高墩柱受侧向压力偏移后纠偏施工技术实例

以某大桥墩柱纠偏为例,通过现场调查确定了具体的纠偏方案,并从施工前期核实桥梁损坏情况、项升纠偏施工、纠偏过程监测等方面对施工方法进行了阐述,为类似工程施工积累了经验.     

横向行驶简支桥板最大内力计算方法探讨

同跨度的横向行驶的简支桥板与通常纵向行驶的简支桥板，在相同设计标准条件下，由于荷载分布情况不同，致使最不利截面和最大内力计算不尽相同，针对横向行驶的简支桥板最大内力计算十分烦琐的特点，推导出较为简便的计算公式，以供参考。     

一种新的半桥零电压开关变换器拓扑

提出了一种新颖的半桥零电压开关主电路拓扑,并详细分析了其工作原理、特点和零电压开关的条件。最后用pspice仿真结果对理论分析进行验证。     

径向基神经网络用于钢-混Π型梁原始断面涡振性能的预测

钢-混Π型梁主梁断面在大跨斜拉桥的主梁设计中被广泛采用,此类断面易出现涡激振动现象,引起桥梁结构安全问题且降低行车舒适性.首先利用既有风洞试验结果校核涡激振动响应的CFD计算模型,并利用校核后的CFD方法得到学习样本数据库.利用学习样本对径向基(RBF)神经网络进行训练,并优化神经网络的设置参数,以此建立钢-混Π型裸梁...     

考虑模态更新的断索作用下斜拉桥动力响应分析方法

为了考虑斜拉桥拉索断索全过程特征和桥梁结构模态时变特性的影响,反映断索事故中斜拉桥结构动力响应的全过程特征,提出一种考虑断索过程模型和结构模态信息更新的突发断索作用下斜拉桥动力响应分析方法,利用数值模拟主要开展了依托斜拉桥桥例分析典型断索场景下桥梁的动力行为特征和研究断索持时对桥梁动力响应特征的影响规律的工作。结果表明:考虑断索过程特征的模态更新方法较不考虑的情况桥梁结构动力响应峰值增幅近10%,同时整体响应也出现略滞后现象;当不同部位单根主塔拉索断裂时,总结得到了全桥主梁结构动力响应较大类型及峰值位置;发现当断索持时大于结构基本周期时,结构动力放大系数变化较小且幅值接近于1.0;当断索持时为0.01~1.0倍结构基本周期时,随着持时缩短结构响应的动力放大系数变大直至峰值。研究结果可为同类桥型考虑突发断索的设计和事后结构评定提供借鉴和参考。     

π型开口截面斜拉桥弯扭耦合涡激共振及气动减振措施研究

针对某大跨径π型叠合梁斜拉桥的气动性能,利用刚性节段模型针对其成桥状态展开了系统的风洞试验研究.试验结果表明,该桥主梁在设计风速范围内存在明显的竖弯及扭转耦合涡激共振现象,即使将竖弯以及扭转阻尼比提高到1％左右,仍然存在明显的涡激共振现象并且振幅超过规范限值.频谱分析表明,该桥主梁断面的竖弯和扭转耦合涡激共振的频率是一...