Research On Evaluation Of Urban Infrastructure Resilience Under Cascading Failure Based On Complex Network Theory

Since the 21 st century,China's urbanization process has accelerated,the scale of cities and towns has expanded rapidly,the functions of cities and towns have expanded continuously,and the population has become more and more dense.However,at the same time,China is faced with various crisis threats such as global warming,extreme climate disasters,earthquakes,etc.,but it lacks the ability to respond to disasters.Developed countries and regions have set off the upsurge of building resilient cities to face various uncertain natural or man-made disasters,which is worth learning from in China.Urban infrastructure is an important foundation for the normal and stable operation of cities and towns.As an important part of urban resilience,infrastructure resilience has always been a research hotspot of foreign scholars.In addition,different types of infrastructure in the infrastructure system are related to each other.Local functional failure of a single infrastructure will lead to cascading failure,which will lead to a large area of infrastructure paralysis.Therefore,enhancing the resilience of infrastructure is an important part of the construction of resilient cities,which can effectively improve the overall ability of cities to cope with disasters,but there is little research on this aspect in China.From the perspective of systematics and space,this paper takes the infrastructure system composed of urban housing,service,electric power,water supply,heat supply and gas infrastructure as the research object,with the goal of optimizing urban infrastructure structure and improving the resilience of infrastructure as the goal,studies the connotation and assessment of infrastructure resilience,constructs the resilience assessment model,and puts forward the resilience promotion strategy Slightly.The specific research contents of this paper are as follows:(1)the establishment of infrastructure topology sub model,including the establishment of infrastructure topology network and the establishment of the relationship between infrastructure layers,and then based on percolation theory,the system cascaded failure deduction model is established to analyze the failure process of infrastructure system when it is disturbed by natural disaster and measure its stability.(2)Based on the infrastructure function sub model and the complex network theory,the infrastructure resilience evaluation model is constructed.According to the three-stage process of infrastructure resilience characteristics network connectivity,redundancy,immunity and resilience,the quantitative formula of resilience and the resilience curve in different situations are obtained.(3)The rationality and feasibility of the model are verified by practical examples,the internal and external relations of infrastructure are determined,the stability of infrastructure is analyzed and its toughness is evaluated comprehensively.The systematic evaluation method proposed in this paper will enrich the methods and research of resilience evaluation,provide theoretical support for the disaster prevention and recovery of infrastructure,promote the effective development of new urbanization in China,and promote the construction and development of resilient cities.