Lifeline earthquake engineering is the application of all relevant knowledge and skill to provide economically feasible engineering safeguards for critical systems such as energy, transportation, water, power, communications, etc. Natural gas and oil pipelines, water and sewage lines, oil and gas storage facilities, tunnels, power, voice and data communication lines and equipment are some of the recognized examples in this relatively new area of interest which has attracted an ever-increasing number of researchers in the past few years.This volume contains most of the papers on lifeline earthquake engineering which were presented at the Third International Conference on Soil Dynamics and Earthquake Engineering, Princeton University, Princeton, New Jersey, USA, 22-24 June 1987. A number of recent major developments in analytical/experimental investigations and field observations for buried pipelines, underground structures and storage tanks were presented by some of the leading experts from the United States, Japan and China.