A comprehensive study is presented for empirical seismic vulnerability assessment of typical structural types, representative of the building stock of Southern Europe, based on a large set of damage statistics. The ob...A comprehensive study is presented for empirical seismic vulnerability assessment of typical structural types, representative of the building stock of Southern Europe, based on a large set of damage statistics. The observational database was obtained from post-earthquake surveys carried out in the area struck by the September 7, 1999 Athens earthquake. After analysis of the collected observational data, a unified damage database has been created which comprises 180,945 damaged buildings from/after the near-field area of the earthquake. The damaged buildings are classified in specific structural types, according to the materials, seismic codes and construction techniques in Southern Europe. The seismic demand is described in terms of both the regional macroseismic intensity and the ratio αg/ao, where αg is the maximum peak ground acceleration （PGA） of the earthquake event and ao is the unique value PGA that characterizes each municipality shown on the Greek hazard map. The relative and cumulative frequencies of the different damage states for each structural type and each intensity level are computed in terms of damage ratio. Damage probability matrices （DPMs） and vulnerability curves are obtained for specific structural types. A comparison analysis is fulfilled between the produced and the existing vulnerability models.展开更多
Various methods have been developed to detect and assess building's damages due to earthquakes using remotely sensed data.After the launch of the high resolution sensors such as IKONOS and QuickBird,it becomes rea...Various methods have been developed to detect and assess building's damages due to earthquakes using remotely sensed data.After the launch of the high resolution sensors such as IKONOS and QuickBird,it becomes realistic to identify damages on the scale of individual building.However the low accuracy of the results has often led to the use of visual interpretation techniques.Moreover,it is very difficult to estimate the degree of building damage(e.g.slight damage,moderate damage,or severe damage) in detail using the existing methods.Therefore,a novel approach integrating LiDAR data and high resolution optical imagery is proposed for evaluating building damage degree quantitatively.The approach consists of two steps:3D building model reconstruction and rooftop patch-oriented 3D change detection.Firstly,a method is proposed for automatically reconstructing 3D building models with precise geometric position and fine details,using pre-earthquake LiDAR data and high resolution imagery.Secondly,focusing on each rooftop patch of the 3D building models,the pre- and post-earthquake LiDAR points belonging to the patch are collected and compared to detect whether it was destroyed or not,and then the degree of building damage can be identified based on the ratio of the destroyed rooftop patches to all rooftop patches.The novelty of the proposed approach is to detect damages on the scale of building's rooftop patch and realize quantitative estimation of building damage degree.展开更多
文摘A comprehensive study is presented for empirical seismic vulnerability assessment of typical structural types, representative of the building stock of Southern Europe, based on a large set of damage statistics. The observational database was obtained from post-earthquake surveys carried out in the area struck by the September 7, 1999 Athens earthquake. After analysis of the collected observational data, a unified damage database has been created which comprises 180,945 damaged buildings from/after the near-field area of the earthquake. The damaged buildings are classified in specific structural types, according to the materials, seismic codes and construction techniques in Southern Europe. The seismic demand is described in terms of both the regional macroseismic intensity and the ratio αg/ao, where αg is the maximum peak ground acceleration （PGA） of the earthquake event and ao is the unique value PGA that characterizes each municipality shown on the Greek hazard map. The relative and cumulative frequencies of the different damage states for each structural type and each intensity level are computed in terms of damage ratio. Damage probability matrices （DPMs） and vulnerability curves are obtained for specific structural types. A comparison analysis is fulfilled between the produced and the existing vulnerability models.
基金Supported by the National Natural Science Foundation of China (Grant No.40701117)Research Foundation for the Doctoral Program of Higher Education of China (Grant No.20070284001)+2 种基金the National Basic Research Program of China ("973" Program) (Grant No.2006CB701300)Foundation for University Key Teacher by the Chinese Ministry of Educationthe "985" Project of Nanjing University
文摘Various methods have been developed to detect and assess building's damages due to earthquakes using remotely sensed data.After the launch of the high resolution sensors such as IKONOS and QuickBird,it becomes realistic to identify damages on the scale of individual building.However the low accuracy of the results has often led to the use of visual interpretation techniques.Moreover,it is very difficult to estimate the degree of building damage(e.g.slight damage,moderate damage,or severe damage) in detail using the existing methods.Therefore,a novel approach integrating LiDAR data and high resolution optical imagery is proposed for evaluating building damage degree quantitatively.The approach consists of two steps:3D building model reconstruction and rooftop patch-oriented 3D change detection.Firstly,a method is proposed for automatically reconstructing 3D building models with precise geometric position and fine details,using pre-earthquake LiDAR data and high resolution imagery.Secondly,focusing on each rooftop patch of the 3D building models,the pre- and post-earthquake LiDAR points belonging to the patch are collected and compared to detect whether it was destroyed or not,and then the degree of building damage can be identified based on the ratio of the destroyed rooftop patches to all rooftop patches.The novelty of the proposed approach is to detect damages on the scale of building's rooftop patch and realize quantitative estimation of building damage degree.
