Seismic Response Behavior of Buried Pipelines

Pipeline damages caused by earthquake excitations in the longitudinal direction of a pipeline have been observed to be a major mode of failure. A simplified quasi-static seismic deformation analysis neglecting the dynamic terms for buried pipelines subjected to earthquake motions in the axial direction is proposed. The analysis involves the solution of a system of static equilibrium equations of a pipeline which consists of rigid pipe-segments and flexible joint springs. Using this model, parametric studies involving soil-pipe interaction parameters, time delay of the traveling seismic waves, soil variations along the pipeline, end conditions and variation of the seismic wave form are performed. Results obtained indicate that the delay time of seismic waves and the non-uniformity of soil resistance have much greater effects on the response behavior of buried pipelines than other parameters.