Multi-Scale Scenario Simulation And 3D Visualization Of Urban Earthquake Disaster

Earthquakes can cause structural damage to buildings in the city,and a series of secondary disasters such as falling of non-structural components and post-earthquake fire.Therefore,reasonable earthquake scenario simulation is of great significance to earthquake emergency rescue and evacuation plans.This work focuses on three critical issues in the seismic scenario simulation of urban areas:(1)scenario visualization of collapsed buildings and selection of emergency shelters at the scale of key cities,(2)pedestrian evacuation considering falling debris at the scale of key regions,and(3)post-earthquake fire rescue training system at the scale of key buildings.Following works are performed:(1)A new experimental methodology of earthquake-induced debris from masonry infill walls is proposed.This methodology considers the influence of the in-plane drift ratio and the out-of-plane acceleration.Based on the experimental results of ten infill wall specimens,the failure criterion of infill walls is given,which can be applied to the calculation of earthquake-induced debris.Moreover,a pseudo-static apparatus for curtain wall glass is designed,and the damage limits of three types of curtain wall glass are given.It is illustrated that point-supported curtain wall glass has sufficient deformation capacity in earthquakes.(2)At the scale of key cities,an urban earthquake scenario simulation method using oblique aerial photography models and GIS data is proposed.Spatio-temporal mapping between building models and time history results for five representative collapse modes are established,and the visualization of earthquake collapse scenario in urban areas is realized.In addition,the existing emergency shelter selection method is improved,which considers the impact of both building collapse and falling debris.The applicability of the improved method is illustrated through a case study of a community.(3)At the scale of key regions,a framework for pedestrian evacuation simulation under the scenario with earthquake-induced falling debris is proposed.Based on brick falling tests and pedestrian movement experiment,debris distribution models and pedestrian velocity models are given.The case study shows the necessity of considering the motion of bricks after hitting the ground,and the influence of falling debris on the pedestrian evacuation.(4)At the scale of key buildings,a simulation framework of an indoor post-earthquake fire rescue scenario is proposed.The seismic damage of the sprinkler system and the suspended ceiling are predicted,and the combination of volume rendering and particle system is employed to realize smoke visualization.The methodology proposed herein can realize the simulation of various disasters and consider the combining effects among the different hazards.Morever,both the realism and computational performance can be balanced.A case study of a 19-story hospital is conducted,which illustrates the necessity of considering the seismic damage of non-structural components and its impact on personnel movement when modeling a post-earthuqake fire rescue scenario.(5)Seismic scenario simulation and 3D visualization of Bao'an District in Shenzhen City are conducted at the scales of key cities,key regions and key buildings.The applications illustrate the scientific value and feasibility of the proposed methodology in urban emergency rescue and evacuation in earthquakes.