The performance of buried pipelines when subjected to earthquake effects -including traveling waves, fault offsets and lateral spreading associated with soil liquefaction and slope failures - has received considerable attention. Field and laboratory observations have led to the formulation of mathematical models of underground pipeline performance that can be used as a basis for design and retrofit of individual pipeline segments, and in damage modules for network simulations. Collection of physical data on pipeline performance from recent earthquakes has illuminated the roles of soil stability, surface rupture and pipeline material and condition. Modeling efforts have similarly advanced. However, there is lacking specific data on how ground movement is translated into pipeline deformation. Laboratory scale testing has not been productive due to the difficulties of simulating boundary conditions, realistic soil deformation and realistic pipeline surface conditions. The purpose of the Parkfield pipeline experiment is to obtain data at field scale under actual earthquake conditions.
The reason for siting the experiment at Parkfield was to capitalize on the predicted recurrence of a M6 or larger earthquake. The USGS has extensively studied and instrumented the region, thereby enriching the data that will be collected.
The validity of the pipeline experiment was demonstrated in the 1989 Loma Prieta Earthquake. In the ensuing years, it became necessary to stabilize the instrumentation and data acquisition systems with equipment upgrades or replacements. Accordingly, this action is for upgrades to the instrumentation and data acquisition and recording equipment, including replacing the strain gages on the steel pipes, upgrading the seismographs and performing other tasks needed to maintain the experiment in a state of readiness.
This project will provide critical data for calibrating design and analysis methods that will eliminate unnecessary conservatism or risk of failure for individual pipelines, and will also validate modules needed in system-level and regional risk assessment and loss mitigation studies for pipeline networks.
