Shaking table tests on buried pipelines in inhomogeneous soil under transverse non-uniform excitation

A series of multi-point shaking table tests are conducted on model pipelines to investigate the seismic response of pipelines buried in inhomogeneous soil under transverse non-uniform seismic excitation. The acceleration and strain response laws of the buried pipelines under different ground motion intensities are analyzed. The main conclusions are as follows: the acceleration response of the pipelines is basically subjected to the acceleration response of the surrounding soil under uniform and non-uniform excitation. The buried pipelines mainly exhibit longitudinal bending deformation. Under the higher uniform seismic excitation, the peak strain of the pipelines in the transient zone where the soil properties change in the inhomogeneous soil model is larger than that in the homogeneous soil model. The maximum peak strain is basically about 30% higher than that in the homogeneous soil, However, the maximum strain peak is basically about 30% lower than that in homogeneous soil under non-uniform excitation. The strain response of the pipelines in homogeneous soil under the higher non-uniform seismic excitation is almost twice as large as that under uniform excitation, but then the strain response of the pipelines in inhomogeneous soil does not change significantly. The test results can provide a reference for the seismic design of large-diameter buried pipelines passing through inhomogeneous soil sites.