Evaluating the Functionality of Water Distribution Networks in the Aftermath of Big Earthquakes Based on Nonlinear Modeling of Pipes Connections

Evaluating the seismic functionality of water distribution networks is of great importance for making decision on either upgrading the vulnerable components of the network, or emergency actions for more critical parts of the city in the aftermath of large earthquakes. In this paper a method is proposed for seismic evaluation of water distribution networks based on nonlinear seismic analysis of piping systems. In the proposed method at first the nonlinear behavior of connections is assessed numerically by finite element analysis (FEA). Then, pipe segments are modeled as beam elements, and the connections by nonlinear springs, whose specification has been assessed by FEA. In the next step, the modeled piping is analyzed subjected to a set of selected accelerograms, to find out which ones of connecting parts fails. In the last step, the amount of water leakage from each crack and the resulting pressure drop in the main pipe and its branches are calculated, to realize the critical components and critical parts of the city network for making decision on the required activities both before and after the earthquake. The proposed method has been applied to a selected part of Tehran metropolis water distribution network to show its efficiency.