Preliminary Research On The Construction Of Seismic Disaster Scenarios In Water Supply Pipeline Network

With the development of urbanization in China,a large number of people,buildings and lifeline systems gather in cities.When an earthquake occurs in the city,the lifeline system is destroyed,which not only affects the normal operation of the city,but also causes secondary disasters.The destruction of water supply pipeline network not only causes economic losses to the city,but also threatens the life safety of residents.The water supply pipeline network is special,and its damage is not easy to be observed.The earthquake disaster scenario construction of water supply pipeline network can truly and intuitively show the earthquake damage and weak links of urban large-scale water supply pipeline network,which is conducive to the development of earthquake disaster risk investigation,disaster relief plan drill and emergency repair of water supply pipeline network after earthquake,and is an important basic work of earthquake disaster risk assessment.At present,in the construction of earthquake disaster scenario in large and medium-sized cities,the research on the visualization method of building earthquake disaster simulation has begun,but the water supply pipeline network has not been involved.This paper studies the construction method of earthquake disaster scenario of water supply pipeline network in large and medium-sized cities,the main content of the paper are as follows:1.The earthquake damage prediction methods of water supply network are summarized.The theoretical analysis method is based on different assumptions to construct the seismic response equation of pipeline and solve the strain,deformation and stress of pipeline.Three calculation methods and characteristics of deformation transfer coefficient between pipe and soil are sorted out,and the characteristics and application scope of each method are analyzed.In this paper,seismic wave input method is used to complete seismic response analysis in disaster scenario construction.This paper summarizes the current classification of pipeline seismic damage,and the prediction and judgment methods of seismic damage for interface pipeline and continuous pipeline.The empirical analysis statistical method can be divided into two categories: the method based on seismic damage data and the method based on Poisson distribution assumption of pipeline failure probability.The difference lies in the range of influence factors involved and the accuracy of calculation results.The judgment method of seismic damage state of pipeline network is given.2.The paper introduces the details of the construction of earthquake disaster scenario of underground pipe network,mainly including the overall technical framework,and expounds the design ideas and implementation process,and the characteristics,application scope,basic elements,working principle and operation mechanism of VTK function library.According to the characteristics and working principle of VTK function library,the construction process of earthquake disaster scenario of underground pipe network is designed.It mainly includes: analyzing the structure of the external pipe network data storage file,and obtaining the required model data from it as the data source;after analyzing the characteristics of inherent data types of VTK and the application scope of operation objects,the filter is selected to convert the point and line data of pipe network into polydata data set;the polydata data sets of 2D points and line segments are processed by filter again to generate the polydata data sets of 3D pipe segments;finally the color mapping between the entity of each pipe segment and the prediction results of seismic response and damage is established,and the rendering of 3D scene of seismic disaster of underground pipe network is completed.3.Taking the main pipe network of Huizhou water supply system as an example,the research methods proposed in Chapter 2 and Chapter 3 are practiced and demonstrated.The pipe material,pipe diameter,joint form,buried depth and site conditions of pipe network are introduced.The 3D pipe network model is constructed by tin algorithm,and the visualization effect of 3D interactive operation is displayed.Then input the seismic data to obtain the seismic response analysis results and seismic damage prediction results of each pipe section,and establish the mapping relationship between the result data and different colors.The results of seismic response time history analysis are presented in the form of color changing with time,which realizes the three-dimensional dynamic visualization of seismic damage scenario simulation of pipeline section.The seismic damage prediction results of pipeline network under different seismic intensities are expressed in different colors,and the seismic resistance performance of the urban underground pipeline network is evaluated.Finally,the visual rendering window interface of earthquake damage scenario simulation is displayed,including VTK pipeline workflow and related settings.