Research On The Reliability Of Post-Earthquake Urban Medical Rescue System Based On Supply And Demand Analysis

When an earthquake disaster occurs,some(or most)functions of the city will fail,but the urban lifeline system,which is used to protect,resist,and rescue earthquake disasters,should not fail.As a subsystem of lifeline engineering,the medical rescue system undertakes the major responsibility of rescuing life after an earthquake,and its ability to resist disasters is determined by the reliability of the system’s functions.Whether the medical rescue system is reliable or not is of great significance to reduce the post-earthquake disaster losses and reduce casualties.In view of this,this research determines the source and sink points according to the two different types of medical rescue supply points and demand points,and then combines the path construction criteria to establish a medical rescue channel including the best,the second best,and the next best three rescue channels system network,and empirical evidence to the main urban area of Chengjiang.Then,on this basis,the seismic reliability of the medical rescue system in the main urban area of Chengjiang under the fortification intensity(VIII)earthquake is simulated: First of all,the seismic reliability of the source point is analyzed by using the semi-theoretical and semi-empirical seismic damage prediction method for a single building.The seismic reliability of the sink is analyzed by the method of earthquake damage matrix of group buildings and the prediction of casualties after earthquake.The seismic connectivity reliability of different road sections is analyzed with the revised model of rubble blockage in mountain cities.Then,the seismic connectivity reliability of different source-sink(OD)point pairs under the Ⅷ degree earthquake is analyzed by means of Monte Carlo simulation test,and the seismic connectivity reliability of the network channel of the medical rescue system under the optimal path is obtained by using the weighted average method.Finally,by dividing and selecting typical OD point pairs of emergency-low reliability and non-emergency-low reliability,find out the middle and lower reliability sections in the medical rescue system network,investigate the reasons,and propose strategies to optimize the entire medical rescue system network.By simulating the seismic reliability of the medical rescue system in the main urban area of Chengjiang under the Ⅷ degree earthquake,the research results are as follows:(1)Among the 4 hospitals(source points)in the main urban area,Chengjiang Traditional Chinese Medicine Hospital was "destroyed" and failed,and could not undertake related work such as medical rescue after the earthquake.(2)Different residential buildings in the main urban area of Chengjiang will be damaged to varying degrees.In all residential quarters and villages(confluence points),a total of 2 people were killed and 74 people were injured due to the collapse of the houses.(3)91.77% of the road sections in the main urban area of Chengjiang are reliable,7.79% of the road sections are moderately reliable,and only 0.44% of the road sections are unreliable.On the whole,the seismic connectivity of each road section in the main urban area is at a high level.(4)The seismic connection reliability value of the network channel of the medical rescue system in the main urban area of Chengjiang based on the optimal path selection is 0.6746,which is moderately reliable and can ensure the smooth progress of most medical rescue work.Among the various road sections involved in the medical rescue channel,93.92% of the road sections are reliable,5.82% of the road sections are moderately reliable,and only 0.26% of the road sections are unreliable.(5)There are23 road sections with medium and lower reliability in the OD point pairs of urgent-low reliability and non-urgent-low reliability: 177,181,182,212,213,214,219,291,295,324,328,329,332,333,334,365,367,370,401,402,427,429,446.The main reasons for the low reliability are that the roads in mountainous cities are of low grade,long and narrow roads,weak seismic fortification levels of buildings on both sides of the roads,and simple road network structures.Accordingly,an optimization strategy is proposed to improve the ability of the buildings on both sides of the road to resist earthquake disasters,expand the rich width of the road,and enhance the redundancy of the road system.This research provides a reference for the improvement of the seismic reliability of the medical rescue system network in other regions of the same type,and also makes a certain contribution to the urban disaster prevention and mitigation work.