Direct Seismic Loss Assessment And Fire Following Earthquake Simulation Of Urban Buildings

Earthquake may induce severe economic loss and post-earthquake fire to the cities in seismic zones.A rational seismic loss assessment and fire following earthquake(FFE)simulation can provide useful information for decision makings,such as disaster prevention and mitigation,and establishment of earthquake insurance system.As a result,the direct seismic loss assessment and FFE simulation of urban buildings are studied in this work.The details are listed below:(1)Based on the FEMA P-58 next-generation building seismic performance assessment method,a practicable approach for refined regional seismic loss prediction is proposed.The seismic responses of a building group are rapidly calculated using the multiple degree-of-freedom models and nonlinear time-history analysis(THA).The implementation and advantages of the proposed method are demonstrated through a case study in which the seismic loss prediction for the buildings in Tsinghua University campus is performed.(2)A seismic loss prediction approach for urban buildings combining the Building Information Modeling(BIM)and the FEMA P-58 method is proposed.The detailed building data are automatically obtained using BIM.The determination of component type and the development of component vulnerability function when the information is incomplete are proposed.The modeling rules and the information extraction for BIM are proposed.An office building is selected as a case study to demonstrate the rationality of the propose method.(3)A framework and an implementation of seismic loss prediction using multiple data sources with different level of details are described.In specific,for the Geographic Information System(GIS)data,the building component type is estimated via the potential fragility classification number,and the structural component quantity is estimated based on the statistics from the available literature and design drawings.(4)A framework for near-real-time seismic loss estimation for buildings is proposed.By taking advantage of the building collapse scene of the disaster area,which can be rapidly identified through remote sensing image analysis,the accuracy of the THA-based loss estimations is improved.Two case studies are performed for demonstration and validation.The results show that the loss estimation of the optimal simulation results is close to the actual loss.The key reason behind is that the proposed method takes advantage of an important information,i.e.the identified situation of building collapse.(5)A framework for physics-based simulation of fire following earthquake is proposed,which can take into account the influence of different ground motions and different building seismic resistances on the fire ignition locations and fire spread.The high-fidelity visualization showing the dynamic process of fire development and the smoke effects are developed using an open source 3D graphics engine and computational fluid dynamics software.The case study of an urban area is performed to demonstrate the rationality of the proposed method.(6)For the buildings with typical structural types and functions,the seismic responses and loss predicted using the method proposed in this study and the widelyused HAZUS method are compared for validation.The results show that the proposed method can take into account the fragility and repair cost of nonstructural components more rationally and in more details.A case study for the San Francisco Bay Area is performed to demonstrate the feasibility of the proposed method for large areas.