Seismic Reliability Analysis On Water Supply Pipeline System

Many investigations have indicated that lifeline system is vulnerable and second damage is serious during earthquakes. As a subdivision of earthquake engineering, lifeline earthquake engineering is causing more and more attentions. Seismic reliability on water supply pipeline system is studied in the dissertation. Both pipe response under the load of earthquake is analyzed, and the performing state of water supply pipeline network after earthquake is evaluated. Research procedures and methods on water supply system are summarized. And new predictive models are discussed. The first part of the thesis studies underground pipeline response caused by the effect of seismic wave propagation, and confirms seismic reliability of pipeline. Anti-seismic design on water supply pipeline according to criterion can抰 completely reflect pipe-soil interaction under dynamic loading. Thus, finite element method (FEM) is employed in the dissertation. The soil surrounding the pipeline is supposed of equivalent linear viscoelastic model. Goodman contact elements are added between pipe elements and soil elements in order to simulate relative slip between pipe and soil. The results are compared with those of psedo- static method. Possible factors that affect pipeline response are analyzed Material characteristics of soil, pipes and joints between pipes are undeterministic, therefore, it is rational to assess pipeline reliability. Statistical experience method resulted from earthquake investigations is introduced. Single factor method and multi-factor method on the base of reliability theory are used to compute seismic reliability. The second part of thesis studies performing state of water supply network after earthquake. Monte Carlo method is employed. Above all, simplified model of water supply network is founded. Then, connectivity probability of each pipeline node is computed on the base of graph theory or fuzzy mathematics. Performing state of pipeline network can beevaluated qualitativelyNewton-RaPhson iterative method is used to calculate water head and fiowrate on nodes. Serviceability Probability of each node can be obtained tbIoughsimulations. Pefforming state of pipeline network can be evaluated quantitatively.Key paths on pipeline netWork can be sorted according to the comprehensivefuzzy evaluaion. The effect of water source is researched basing on weightedevalUaion method. MuIti-factor model is founded to make sure of pipeline keyPatri.The third part of the thesis discusses predichve models of seismic responseanalysis and systemic cormectivity analysis, founded on the base of neuralnetWork technologyNeural netWork technology is extensively aPPlied to many fields duringrecent years. Basic knoWedge about neural netWork and BP netWork model areintrduced in the pat. Seisndc response model and systemic connectivity modelare fotmded to attemPt to raPidly evaluated pipeline pefforming state afterearthquake.