The appendix presents summaries of statements made by representatives of various federal agencies and other organizations contacted during the study. This report provides an inventory of the major lifeline systems in the Cajon Pass. It also describes the earthquake and geologic analysis tools available to identify and define the level of seismic risk to those lifelines. The vulnerabilities occurring from the siting of multiple lifeline systems in confined and at-risk areas due to their interactions from natural and manmade disasters are evaluated. Potential mitigation techniques for communication lifelines, electrical power lifelines, fuel pipelines, and transportation lifelines are identified.
Detailed maps indicate lifeline locations.
Discussions are presented on seismic hazards and predictive models that can be used to evaluate the damage potentials associated with the various seismic hazards, such as ground shaking, landslides, and liquefaction. This report presents a new analysis method to identify the increase in the seismic vulnerability of individual lifeline systems due to their proximity to other lifelines in the Cajon Pass, located in southern California. It assumes an earthquake event similar to the 8.3 magnitude 1857 Fort Tejon earthquake. The method calculates a parameter that can be used to adjust the damage state values for shaking as determined by the ATC-13 damage probability matrices. The primary objective of the study was to determine how the times to restore full service would be affected by the collocation of several types of lifelines in the same congested corridor.