Evaluation of response characteristics of buried pipelines during earthquakes

Abstract

This paper presents an evaluating method for seismic behaviour of pipelines during earthquakes and studies the response characteristics of them for various conditions of ground displacements and pipelines. The proposed method consists of mainly two analytical methods which are the seismic response analysis of surface ground layers and the pseudo static response analysis of buried pipelines. The seismic response analysis method for surface ground layers is 2-dimensional effective stress analysis based on Biot's two phase mixture theory and Iai's constitutive equation. The pipeline analysis is based on a beam theory on an elastic foundation and modified transfer matrix method. Numerical computations are performed for various models with changing conditions of ground and pipes. As a result, axial and lateral response characteristics of pipelines are shown and evaluated by relating with earthquakes, grounds and pipelines conditions.

Seismic response characteristics of buried pipelines subjected to large ground movements during huge earthquakes

“…The second method is the pseudo static response analysis for the buried pipeline. This method is based on the beam theory on an elastic foundation and modified transfer matrix method [4][5][6][7]. The flow of this synthetic method is shown in Figure 1.…”

“…The responses of pipelines subjected to the ground displacement induced by liquefaction or seismic wave are analyzed by using the program "PIPE" [4][5][6][7], which is based on the beam theory on an elastic foundation. Replacing the stiffness of liquefied or non-liquefied ground around the pipeline with a coefficient of subgrade reaction, the pipeline is modeled as pipeline-soil spring system as shown in Figure 2.…”