Seismic Response of Parallel Double Pipelines to Longitudinal Ground Motions

Abstract

The failure of one pipeline may compromise the integrity of adjacent pipelines, especially for closely spaced parallel pipelines. This paper presents a series of multipoint shaking table tests of parallel double pipelines, which were installed in sand beds with three different spacing values to assess the effect of spacing on the seismic response of parallel pipelines. The acceleration and strain data were collected during the shaking tests. The results demonstrated that the acceleration response of soil between the two pipelines under uniform and nonuniform excitation was relatively lower than that of the pipelines due to the influence of the adjacent double pipelines, especially for the nonuniform excitation case. The maximum peak strain values of both pipelines gradually increased as the spacing between them increased under uniform excitation at lower loading intensity. However, for nonuniform excitations and uniform excitation of higher loading intensity, the maximum peak strain of pipelines with spacing of 150 mm was smaller than that with spacing of 100 and 200 mm. These results indicate that the combination of different pipeline spacings and nonuniform excitation could make the pipeline dynamic response more complicated, which should be properly considered in the seismic design of parallel double pipelines.