遥感分类方法在建筑物震害提取中的应用（以玉树地震为例）

建筑物损毁情况是地震灾害评估的一项重要指标,利用遥感技术快速提取震后建筑物震害信息,对科学指导地震应急救援工作具有重要意义.利用2010年4月14日青海玉树7.1级地震前后玉树县结古镇团结村高分辨率遥感影像,结合像素光谱和空间特性的纹理、结构等多源信息,基于支持向量机（SVM）方法,对地震前后建筑物信息进行分类提取,变化检测出建筑物损毁情况,并与面向对象多源信息复合的模糊分类法的分类精度、提取效率进行对比分析.研究结果表明,多源数据复合的SVM影像分类方法能够有效解决模糊分类影像破碎问题,地震前后两实相影像分类总精度达到77.53％和73.56％,提高了建筑物震害信息提取精度.     

室外风对高层建筑外保温层火灾发展的影响研究

近年来,由外墙保温材料引起的高层建筑火灾频繁发生,使得高层建筑室外火灾已经成为当下防火安全工程研究的热点议题。高层建筑外墙火灾受室外风影响较大,本研究采用CFD（Computational Fluid Dynamics）火灾模拟软件FDS,针对当前典型高层住宅建筑进行室外风作用下外保温材料火灾特性的模拟研究,分析了不同风向风速作用下外墙保温材料的火灾燃烧性能,研究了室外风对火灾烟气温度、运动速度、CO体积分数、可见度、火灾热释放速率等参数的影响。研究结果表明：室外风对火灾热释放速率等火灾作用参数有着较大影响,并存在一定的规律性。研究成果对未来高层节能建筑的防火设计施工具有一定的借鉴意义。     

Response of tall cantilever wall buildings to strong pulse type seismic excitation

This paper investigates the seismic response of tall cantilever wall buildings subjected to pulse type ground motion, with special focus on the relation between the characteristics of ground motion and the higher‐modes of response. Buildings 10, 20, and 40 stories high were designed such that inelastic deformation was concentrated at a single flexural plastic hinge at their base. Using nonlinear response history analysis, the buildings were subjected to near‐fault seismic ground motions and simple closed‐form pulses, which represented distinct pulses within the ground motions. Euler–Bernoulli beam models with lumped mass and lumped plasticity were used to model the buildings. The response of the buildings to the closed‐form pulses fairly matched that of the near‐fault records. Subsequently, a parametric study was conducted for the buildings subjected to three types of closed‐form pulses with a broad range of periods and amplitudes. The results of the parametric study demonstrate the importance of the ratio of the fundamental period of the structure to the period of the pulse to the excitation of higher modes. The study shows that if the modal response spectrum analysis approach is used — considering the first four modes with a uniform yield reduction factor for all modes, and with the square root of sum of squares modal combination rule — it significantly underestimates bending moment and shear force responses. A response spectrum analysis method that uses different yield reduction factors for the first and the higher modes is presented. Copyright © 2011 John Wiley & Sons, Ltd.     

Code‐based record selection methods for seismic performance assessment of buildings

The recent concerns regarding the seismic safety of the existing building stock have highlighted the need for an improvement of current seismic assessment procedures. Alongside with the development of more advanced commercial software tools and computational capacities, nonlinear dynamic analysis is progressively becoming a common and preferable procedure in the seismic assessment of buildings. Besides the complexity associated with the formulation of the mathematical model, major issues arise related with the definition of the seismic action, which can lead to different levels of uncertainty in terms of local and global building response. Aiming to address this issue, a comparative study of different code‐based record selection methods proposed by Eurocode 8, ASCE41‐13 and NZS1170.5:2004 is presented herein. The various methods are employed in the seismic assessment of four steel buildings, designed according to different criteria, and the obtained results are compared and discussed. Special attention is devoted to the influence of the number of real ground motion records selected on the estimation of the mean seismic response and, importantly, to the efficiency that is achieved when an additional selection criteria, based on the control of the spectral mismatch of each individual record with respect to the reference response spectrum, is adopted. The sufficiency of the methods with respect to the pairs of M–R of the selected group of records and the robustness of the scaling procedure are also examined. The paper closes with a study which demonstrates the suitability of a simplified probability‐based approach recently proposed for estimating mean seismic demands. Copyright © 2015 John Wiley & Sons, Ltd.     

辽宁省农村民居抗震性能分析研究

本文以建筑物结构、建筑年代、地基类型及现状等几个方面,系统地统计分析了辽宁省农村民居的现状。基于统计分析方法,对辽宁省的农村民居抗震性能及空间分布状况进行了分析研究,并给出了辽宁地区农村民居防震减灾对策与建议。     

交叉环绕航线下的城市级复杂建筑物实景三维建模

目前各省、市正在加快推进实景三维中国建设,其中城市级实景三维建模相较于地形级,精度要求更高,展示内容更丰富,工作量更大。针对高低错落且结构复杂的建筑物场景,常用的提高无人机航线重叠度的方法,改进效果不明显,仍存在较多拉花变形区域,且会导致影像数量增加、飞行和建模过程更加耗时、生产成本增大的问题。因此,本文提出了无人机交叉环绕航线下的城市级实景三维建模方法,选取典型试验样区进行航摄建模试验,并与采用常规五向航线航摄的方法进行建模效率、质量、精度方面的对比分析。结果表明,交叉环绕航线航摄方法可大幅减少影像数量,节省空三计算和建模时间,提升整体建模效率;且在建筑物的门顶雨篷、玻璃窗户等难点区域,建模质量更好,整体精度更高,满足相关标准规范要求。     

结构地震行波效应分析综述

从时域和频域两个方面介绍了行波效应下结构地震响应的各种分析方法及各方法的优缺点和适用范围,后对桥梁结构、大跨空间结构、普通建筑结构、大坝结构、地下结构等各类结构体系在行波效应下的结构地震响应特征作了简要总结,阐述了国内外在行波效应研究中已取得的成果和结论,并对未来研究重点问题提出了自己的见解。     

1949年以来兰州城市资本密度空间变化及其机制

构建了计划经济体制和中国转型期城市资本密度空间分布理论模型,并以兰州市为例进行了实证.利用高精度卫星影象和大规模实地调查方法获取数据,采用GIS手段和数理统计方法,利用建筑高度指标,分区、分行业对兰州城市资本密度空间变化进行了深入研究.同时,采用资本存量增量(或增长率)/建成区面积增量(或增长率)的指标衡量资本角度的城市紧凑化程度,研究了城市紧凑化变动过程.结果表明:①中国计划经济体制下的城市资本空间密度为缓慢波动下降或均衡分布规律,甚至出现上升趋势.转轨期(中国)城市资本空间密度由中心到外围的相应规律则居于两者之间,存在向市场经济空间模型靠近的趋势;②中国城市计划经济体制下的用地空间由中心到外围呈现商务→住宅→工业→农业的模式,而转轨期依然基本保留了此特征;③转轨期的建筑高度提高速度存在加速趋势,住宅、商业、办公等类建筑高度明显高于计划时期,其空间分布模型也更接近市场经济体制模型;④从资本视角审视,中国城市将更加紧凑化,且随时间的推移,城市资本密度空间变化曲线大致存在较为明显的"雁行波动上升式"规律.     

结合天然地震推导水库地震的建筑物易损性

通过类比的方法,选择有现场调查资料并有建筑物破坏比结果的天然地震,基于地震中建筑物震害表现的一致性,以震级、震源深度和极震区烈度为标准,聚类得到与水库地震震害相似的天然地震震例。考虑到宏观经济水平与地震经济损失已有的统计模型,采用了人口密度、人均GDP和三产比例等3个宏观经济指标来反映不同地区的建筑物总体抗震水平,以加权海明(Hamming)距离来定义已知矩阵与目标矩阵的近似度,最终的加权结果即为待求地区的易损性矩阵。通过实际检验,所得的建筑物易损性关系能够反映水库地震的破坏特点,较中强天然地震的易损性要高。这种工作思路也可以用于水库地震其它方面的研究中     

东莞市历史建筑数字化保护研究

本文通过对东莞市获批的278处历史建筑的现场调研,采用无人机、三维激光扫描等空问信息技术实现信息采集和数字化建库,结合数字化管理平台与公众服务系统全方位展示和传播东莞市历史建筑的文化价值.旨在探索数字化技术与历史建筑保护相结合的新模式,为传统文化资源的保存、保护、活化利用及传播提供新思路,从而推动历史建筑保护管理工作向...