Seismic response modeling of water supply systems

This thesis describes a comprehensive model for simulating the earthquake performance of water supply systems. This model is developed in conjunction with the water supply system operated by the Los Angeles Department of Water and Power (LADWP) and validated by a favorable comparison of simulation results with observations and flow measurements for the heavily damaged LADWP water supply after the 1994 Northridge earthquake.; Earthquake performance of water supply systems is simulated using hydraulic network analysis. Hydraulic simulation procedures for heavily damaged water supply systems are developed on the basis of an iterative approach to isolate the network nodes with negative pressures step by step, starting with the one of highest negative pressure. The isolation approach accounts accurately for reliable flows and pressures in the damaged system. The isolation approach removes unreliable flows, and identities vulnerable parts of the damaged system for mitigation.; To predict earthquake damage to underground water supply pipelines an analytical model is developed for surface wave interaction with jointed concrete cylinder pipelines (JCCPs). A dimensionless chart is developed for estimating the joint pullout of JCCPS under the action of seismic waves. This model is applied to analyze seismic wave interaction with other jointed pipelines, such as cast iron (CI) pipelines with lead-caulked joints. Dimensionless reduction curves are developed for estimating joint pullout associated with brittle and ductile joint performance.; Pipeline damage in hydraulic simulations is classified as breaks and leaks. A break is simulated by disconnecting the original pipeline completely and opening the broken ends into the atmosphere; a leak is simulated as an orifice in the pipe wall. Energy loss from the leak is accounted for as minor losses. Five different scenarios of leakage are simulated as a function of pipe diameter.; Seismic performance of the LADWP system is simulated using a multi-scale technique. This technique explicitly accounts for 2.200 km of pipelines, associated with the LADWP trunk system, and simulates the remaining 9,800 km of distribution lines by fragility curves relating demand to repair rate in the distribution network. Repair rate, in turn, is correlated with peak ground velocity. The fragility curves are developed on the basis of LADWP distribution network simulations.; A computer code, GIRAFFE, is developed for the implementation of the model. GIRAFFE builds on an open source hydraulic network analysis engine, EPANET, and works in conjunction with Geographical Information Systems (GIS) for simulation result presentations.