摘要：Due to the randomness of earthquake wave magnitude and direction, and the uncertain direction of strong axis and weak axis in the construction of engineering structures, the effect of the direction of ground motion on a structure are studied herein. Ground motion records usually contain three vertical ground motion data, which are obtained by sensors arranged in accordance with the EW （East -West） direction, NS （South- North） direction and perpendicular to the surface （z） direction, referring to the construction standard of seismic stations. The seismic records in the EW and NS directions are converted to Cartesian coordinates in accordance with the rotation of θ = 0°-180°, and consequently, a countless group of new ground motion time histories are obtained. Then, the characteristics of the ground motion time history and response spectrum of each group were studied, resulting in the following observations： （1） the peak and phase of ground motion are changed with the rotation of direction θ, so that the direction θ of the maximum peak ground motion can be determined; （2） response spectrum values of each group of ground motions change along with the direction θ, and their peak, predominant period and declining curve are also different as the changes occur; then, the angle θ in the direction of the maximum peak value or the widest predominant period can be determined; and （3） the seismic response of structures with different directions of ground motion inputs has been analyzed under the same earthquake record, and the results show the difference. For some ground motion records, such as the Taft seismic wave, these differences are significant. Next, the Lushan middle school gymnasium structure was analyzed and the calculation was checked using the proposed method, where the internal force of the upper space truss varied from 25% to 28%. The research results presented herein can be used for reference in choosing the ground motion when checking the actual damage to struct

摘要：This paper describes a set of on-site earthquake safety evaluation systems for buildings, which were developed based on a network platform. The system embedded into the quantitative research results which were completed in accordance with the provisions from Post-earthquake Field Works, Part 2： Safety Assessment of Buildings, GB18208.2 -2001, and was further developed into an easy-to-use software platform. The system is aimed at allowing engineering professionals, civil engineeing technicists or earthquake-affected victims on site to assess damaged buildings through a network after earthquakes. The authors studied the function structure, process design of the safety evaluation module, and hierarchical analysis algorithm module of the system in depth, and developed the general architecture design, development technology and database design of the system. Technologies such as hierarchical architecture design and Java EE were used in the system development, and MySQL5 was adopted in the database development. The result is a complete evaluation process of information collection, safety evaluation, and output of damage and safety degrees, as well as query and statistical analysis of identified buildings. The system can play a positive role in sharing expert post-earthquake experience and promoting safety evaluation of buildings on a seismic field.

摘要：高层建筑的基本自振周期是十分重要的结构动力特性,通过对特定结构形式的高层建筑进行现场测试,归纳总结一定规律,给出结构自振周期经验公式,可快速估算结构的动力特性及其承受的地震作用和风荷载。基于上海市9幢典型高层建筑的动力性能现场测试数据,识别了结构的基本自振周期并进行了统计分析;针对现行规范中有关高层框架-剪力墙结构的基本自振周期经验公式是基于高度在50 m以下的结构实测数据拟合而成的现状,给出了高度在30~130 m之间的结构在水平纵横两个方向上的基于结构高宽比的基本自振周期经验公式;首次给出了高度在90~190 m之间高层框架-核心筒结构在水平纵横两个方向上基本自振周期经验公式。给出的公式可供结构设计人员在高层建筑的初始设计阶段参考使用,该公式是对我国《建筑结构荷载规范》(GB50009-2012)的补充和完善。

摘要：计算超越强度倍率值的砌体结构震害预测方法是一种简单可靠的方法,为了使这种方法更容易理解应用及与新规范一致,在分析其计算公式和简化过程基础上,依据现行抗震设计规范,推导给出了考虑构造柱影响的屈服加速度计算公式和考虑正应力影响的砌体抗剪强度计算公式,即新的超越强度倍率E计算方法;并利用新方法计算了白鹿中学‘求知楼’和‘勤学楼’在不同地震烈度作用下的预期结构破坏状态。计算结果表明,新方法计算的砌体抗剪强度和屈服加速度要比原方法较大且整体的震害预测结果也比原方法较轻,更为接近实际情况。

摘要：为了研究平面内刚度不均匀性对底框结构抗震性能的影响,提出了局部平均刚度比的概念。建立具有不同局部平均刚度比的ABAQUS有限元模型,并进行弹塑性时程分析。分析结果表明：平面内刚度分布不均匀会导致局部墙体严重破坏,从而影响结构整体的安全性。局部平均刚度比作为衡量同一楼层平面内局部区域刚度大小的指标,其值过低时会造成该区域抗侧刚度不足,墙体破坏严重;过高时会造成薄弱部位转移,对平面内其他区域的墙体产生不利影响。综合分析以上结果,建议底框结构的局部平均刚度比控制在0.66-1.30,该结论可作为我国抗震规范平面内刚度分布的补充规定,为结构设计提供参考。

摘要：汶川地震映秀镇漩口中学5幢教师宿舍裂而不倒,1幢学生宿舍底层倒塌,因抗震构造措施截然不同。该实例表明,采用构造柱圈梁抗震体系的多层砖砌体住宅楼,可达到大震不倒的设防目标。本文将楼层综合抗震能力指数发展为抗倒能力指数,用以判别多层砌体房屋的抗倒能力,实施其抗倒设计。

摘要：主要比较分析了超限高层建筑中基于性能抗震设计方法与常规抗震设计方法,并就目前我国的超限高层建筑结构的特点,详细的分析了超限高层结构基于性能抗震设计中的抗震性能水准以及性能目标的组成,希望能够为我国超限高层建筑的性能抗震设计有些帮助。

摘要：目前的AASHTO LRFD桥梁规范主要考虑重力荷载和卡车等活荷载的组合情况,而没有在概率基础上考虑地震等极端荷载的组合问题。包括LRFD在内的很多桥梁抗震规范都是主要考虑地震的作用,甚至设计时不考虑其他荷载的作用,LRFD设计指导手册中在考虑地震等极端荷载时,也只是提到在特殊情况和桥梁比较长的情况下再考虑卡车的作用,而且,也比较模糊。文中在考虑地震荷载与卡车荷载时将其视为2种随机过程函数,并分析其各自的荷载特点。结合最近一些年USGS收集的极端荷载数据,文中认为桥梁设计(考虑地震和重卡车设计)时应该综合考虑地震和重卡车的影响,对它们进行荷载组合。接着,文中简单回顾了几种荷载组合方法,对比之后,认为FerryBorges(也称Ferry Borges-Castanheta模型)模型考虑了荷载的持时因素与荷载发生概率,虽然也对荷载做了极大的简化,但很好地解释了随机过程转化成随机变量以及与其他随机变量组合的复杂问题。最后,本文以美国西雅图地区的一桥梁为研究对象进行了算例分析。

摘要：多种极端灾害给桥梁带来的严重后果强调说明了桥梁多灾害设计研究的重要性和必要性,而目前国内外的桥梁设计规范并没有考虑多种极端灾害的共同作用。首先回顾了多灾害理论在桥梁设计中的提出和发展,以及存在的问题。很多学者进行了两个极端荷载下桥梁多灾害响应的尝试,包括用优化理论寻找设计最优解、用试验验证多灾害设计的桥梁构件、用实测数据进行易损性分析以及用分项失效概率理论进行多灾组合等。进而介绍了几种主要的荷载组合理论在多灾害组合中应用。基于全寿命理论的桥梁设计越来越受到研究者的重视,它能够在桥梁全生命周期中考虑多灾害等因素,是未来多灾害研究的重要方向。

摘要：探讨了震害遗址保护性加固的设计原则。考虑到震害遗址的功能应能反映震害状况,并可以供科考参观,建议加固原则为要尽量避免影响震害现象,保持遗址结构的稳定承重和在常遇地震下不倒塌。保护性加固工程的安全冗余度可略低于常规结构。加固设计应合理估算原结构构件的震损程度,并以此作为加固设计的依据。接着,介绍了四川白鹿镇中法友谊桥遗址的保护性加固设计:通过震害调查确定结构的基本尺寸,采用ABAQUS有限元实体建模进行了遗址结构的受力分析,结合遗址结构特点制定了加固方案。分析表明,加固方案显著加强了拱桥遗址的抗震承载能力,能够满足震害遗址的保护性加固要求。