Vulnerability of simple reinforced concrete buildings to damage by rockfalls

A procedure is presented for investigating the response of reinforced concrete buildings to rockfall impact. The method considers a single rock hit on the basement columns, and it includes four steps: (a) calculation of the probability of a rock impact on a member of the load-bearing system, taking into account the block size and the design of the structure; (b) evaluation of the response of one or more structural elements to the hit based on element capacity; (c) in the case of structural element failure, assessment of the robustness of the whole structural system, calculating the potential for progressive collapse; and (d) calculation of a damage index (DI), which is the ratio of structural elements that fail to the total number of structural elements. The proposed method is applied to a reinforced concrete building for a range of rockfall paths and intensities. The analysis has been carried out for a 2-m-diameter block and velocities < 3.5 m/s. The possible damage range is found to be highly variable, with DI values ranging from 0.01 to 1 depending on the impact location and block velocity.     

Assessment of wind speeds that damage buildings

A method to determine the wind speed to cause damage to buildings is described. The method is based on engineering calculations of wind loads generated on the weakest links of buildings such as the roof-to-wall joints of a wood-frame house. Data needed for the calculation include wind direction, building geometry, conditions of windows, doors and other exterior openings immediately before the occurrence of wind damage, and details of the weakest links that initiated the failure. The method can be used for estimating the maximum wind speed of a storm from an in-depth post-disaster investigation. Results of this study indicate that it takes no more than the wind speed of a F-2 tornado to completely destroy either a wood-frame house or a nonreinforced masonry building. The study supports the belief that the wind speed associated with F-3, F-4 and F-5 tornadoes are grossly overrated.     

Post-processing HAZUS earthquake damage and loss assessments for individual buildings

Natural Hazards - Building damage probabilities are invaluable for assessing short-term losses from natural hazards. In many countries however, the individual building level data required for...     

Observations of damage to buildings from M w 7.6 Padang earthquake of 30 September 2009

On 30 September 2009 at 05:16?pm local time (10:16 am UTC), a major earthquake registering a magnitude M _w 7.6 occurred off the coast of Padang in West Sumatra. This paper presents the observations from a reconnaissance mission that investigated the performance of structures, infrastructure and geotechnical structures within the affected region. As well as presenting the detailed observations made on the mission, insights as to why structures failed and deficiencies in the construction practices of the region are also presented. Considering the high seismic risk of this area and that seismic gaps suggest another earthquake with a magnitude greater than 8.7 may occur, these observations are particularly significant. One of the vital features of this earthquake was a number of very large and devastating landslides that occurred in the district of Pariaman. These landslides were not only extensive, but had an extremely high lethality. Another key feature of the earthquake was the surprisingly high number of government buildings that collapsed. The paper concludes by presenting a number of recommendations for both the rebuilding of failed structures as well as for hazard assessments of existing structures and geotechnical features.     

Flood vulnerability assessment of residential buildings by explicit damage process modelling

Natural Hazards - The present paper introduces a vulnerability modelling approach for residential buildings in flood. The modelling approach explicitly considers relevant damage processes, i.e....     

地震在滑坡体上的响应形式研究:以苦地瓜子滑坡为例

地震滑坡分为三大类,即高度破裂或严重高度破裂滑坡、存在分离剪切面的滑坡以及以流相为主的滑坡。在中国西
南地区,根据地震滑坡特点,按其运动方式划分为：推移式滑坡、牵引式滑坡、溜滑性滑坡和崩塌性滑坡四大类。在四川
省茂县苦地瓜子滑坡特征的调查中,发现了一些较为特殊的地质现象,主要包括以下几点：（1） 滑坡上游边界冲沟中湖相
沉积和滑坡体上分布的湖积物表明苦地瓜子滑坡曾经发生过堵江事件,部分为堵江后的堰塞湖区域,在此区域发生河湖相
沉积,其结果是滑坡此部分被湖积物所覆盖,呈现出了与其他几个区覆盖物截然不同的现象;（2） 苦地瓜子滑坡中下部发
现砂土液化现象及规律性排列的裂缝;（3） 踏勘时在滑坡中下部发现直立错坎,错坎两侧土性不同,在颜色和物质组成上
都有较明显不同。错坎左侧为粉土状物质,而右侧以碎石土为主;（4） 在滑坡的中部以及中偏下部位都发现有平行于滑动
方向的裂缝;（5） 现场调查时在坡体中上部发现有充填楔,充填物颗粒较大、磨圆度较好,与地面盖层的颜色、岩性条件
相同。综合各种现象进行分析,室内试验和数据统计,认为茂县苦地瓜子滑坡为地震诱发的滑坡,并且可以从此滑坡中发
现地震滑坡与普通滑坡明显不同,往往在现场留下自重引起的滑坡不好解释的现象,主要有砂土液化迹象、充填楔、地震陡
坎、平行于滑动方向的裂隙;此外地震滑坡还具有等时性和群发性的特点。     

滑坡联动在滑坡及滑坡群中作用分析——以千将坪滑坡为例

受2003年7月13日千将坪滑坡的影响,位于其北东侧牵引区的千将坪东滑坡大范围出现了因拉张和剪切作用形成的裂隙.本文研究了因滑坡联动作用而形成的牵引区特征,对千将坪滑坡发生时在千将坪东滑坡体上所产生的裂隙形成作用方式进行了研究,并分析了千将坪滑坡体不同部位在滑坡滑动过程中的相互牵引与影响方式.通过研究分析,将滑坡滑动时的牵引方式简单分为以拉张卸荷为主和以边界剪切为主的两种模式,并以这两种牵引模式来分析白果树滑坡群中各个滑坡之间的相互制约关系,拟通过从滑坡联动作用阐述千将坪滑坡以东白果树滑坡群的整体稳定及局部失稳对滑坡群整体稳定性的影响.     

滑坡预报研究方法综述

目前常用的各种滑坡预报的理论和方法很多,其中斋藤迪孝模型、灰色预模型（１．１）、Ｐｅａｒｌ生物生长模型和非线性相关分析模型又是预报理论更为充分、研究较为深入、预报效果更有效的方法;对各种方法的原理、适用条件和优缺点进行了剖析。同时,还对其它一些预报方法做了介绍。     

DP Matrix3D近景摄影测量系统在滑坡监测中的应用

介绍近景摄影测量系统在滑坡监测中应用及系统的关键技术,以福州晋安区宦溪鼓岭滑坡监测中的应用实例,探讨近景摄影技术在滑坡监测中应用优点及局限条件。     

Deterministic Landslide Risk Assessment at a Past Landslide Site

The slope failure and landslide hazard will possess the same properties within a range including the same engineering geological conditions. To assess the landslide risk of a mountainous area, the study of landslides previously having occurred is very important to evaluate the landslide risk around the area in which they took place. Based on the study of the mechanism of a previous landslide recorded in Kumamoto, Japan, this study initially proposes mechanical parameters for evaluating the landslide hazard using a 3D slope stability method. For each slope unit in the study area, the critical slip surface, which reveals the minimum safety factor of a slope, can be obtained. The affected streams and range of possible landslide masses are analyzed based on the debris flow simulation. This is initially applied to simulate the past landslide event and the result shows the landslide-deduced debris flow effectively re-displayed. Overlayered with layers of infrastructure in Geographic Information Systems (GIS), this risk map indicates which houses and road sections remain in dangerous areas.     

Vulnerability of buildings to debris flow impact

Quantitative risk assessments (QRAs) for landslide hazards are increasingly being executed to determine an unmitigated level of risk and compare it with risk tolerance criteria set by the local or federal jurisdiction. This approach allows urban planning with a scientific underpinning and provides the tools for emergency preparedness. Debris-flow QRAs require estimates of the hazard probability, spatial and temporal probability of impact (hazard assessment) and vulnerability of the elements at risk. The vulnerability term is perhaps the most difficult to estimate confidently because (a) human death in debris flows is most commonly associated with building damage or collapse and is thus an indirect consequence and (b) the type and scale of building damage is very difficult to predict. To determine building damage, an intensity index (I _DF) was created as the product of maximum expected flow depth d and the square of the maximum flow velocity v (I _DF = dv ²). The I _DF surrogates impact force and thus correlates with building damage. Four classes of building damage were considered ranging from nuisance flood/sedimentation damage to complete destruction. Sixty-six well-documented case studies in which damage, flow depth and flow velocity were recorded or could be estimated were selected through a search of the global literature, and I _DF was plotted on a log scale against the associated damage. As expected, the individual damage classes overlap but are distinctly different in their respective distributions and group centroids. To apply this vulnerability model, flow velocity and flow depth need to be estimated for a given building location and I _DF calculated. Using the existing database, a damage probability (P _DF) can then be computed. P _DF can be applied directly to estimate the likely insurance loss or associated loss of life. The model presented here should be updated with more case studies and is therefore made openly available to international researchers who can access it at .     

用滑坡解释一些地质现象的讨论——以双龙煤矿HP1号滑坡为例

在矿区地质勘查中,一些大型的老滑坡体,由于经过后期的风化剥蚀改造,从地形地貌上不容易识别出来,其产生的各种地质现象被误认为是断层原因所致,尤其是在贵州省煤矿矿区,一些大、中、小型的老滑坡普遍存在.文章以习水县双龙煤矿HP1号滑坡为例,在用构造得不到合理的解释情况下,通过滑坡得到合理的解释,并找到滑坡相关的的证据.     

桩板式挡土墙在滑坡治理中的应用

桩板式挡土墙采用钢筋混凝土结构,由悬臂式抗滑桩和挡土板组合而成,能承受较大的土压力。通过对工程实例的地质条件,滑坡情况进行分析,从而选用不同型号的桩板式挡土墙进行滑坡治理。实际证明,该治理方法在滑坡治理及边坡支护中起到不可替代的作用。     

Landslide risk assessment

Landslide risk can be assessed by evaluating geological conditions associated with past events. A sample of 2,4 16 slides from urban areas in West Virginia, each with 12 associated geological factors, has been analyzed using SAS computer methods. In addition, selected data have been normalized to account for areal distribution of rock formations, soil series, and slope percents. Final calculations yield landslide risk assessments of <0.50=low risk, 0.50 to 1.50=moderate risk, and >1.50=high risk. The simplicity of the method provides for a rapid, initial assessment prior to financial investment. However, it does not replace on-site investigations, nor excuse poor construction.     

Impact of spatial correlation of ground motions on seismic damage for residential buildings in Bucharest,Romania

Natural Hazards - This paper focuses on the investigation of seismic risk for residential buildings situated in Bucharest, the capital city of Romania. With a population of nearly 2 million...     

开采建筑物损坏的集对分析——可变模糊集综合评价模型

应用集对分析和可变模糊集理论,探讨了开采建筑物损坏等级的综合评价模型,建立了以集对模糊联系度构建可变模糊集差异度的新方法,实例及同其他方法对比应用,表明了应用集对分析—可变模糊集方法评价开采建筑物损坏等级,可简化评价过程和提高定量分析的可靠性,评价结果更接近样本的实际情况。     

Determination of building age for Istanbul buildings to be used for the earthquake damage analysis according to structural codes by using aerial and satellite images in GIS

Natural Hazards - Istanbul is located in one of the most active seismic zones in the world. Since Istanbul is the industrial, commercial, cultural and educational center of Turkey, it attracts...     

巴东县西壤坡西滑坡稳定性分析与防治对策研究

巴东库岸段主要出露中三叠统巴东组二段(T2b2)红层,为软岩、硬岩相间,遇水极易软化,常发育大量滑坡,且潜在不稳定滑坡较多,而三峡工程的建设必将诱发并导致巴东库岸段滑坡地质灾害的发生.分析了西壤坡西滑坡的特征、滑坡发生的机理,并进行了稳定性计算,计算结果表明该滑坡的稳定性较差,对此提出了相应的防治对策.