SEISMIC VULNERABILITY ANALYSIS OF PIPELINE CONSIDERING THE INFLUENCE OF NEAR-FAULT PULSE-TYPE GROUND MOTION

The near-fault pulse-type ground motion has short-time and high -energy pulse characteristics, which will cause serious damage to long-period structures such as buried pipelines. In order to study the seismic performance of buried pipeline affected by near-fault pulse-type ground motion, the directional pulse component and slip impulse component of different ground motions are simulated by the grounds of a simplified velocity pulse model, combined with the empirical statistical formula of pulse period and pulse peak. The near-fault pulse-type ground motions with multiple frequency components are synthesized by superposing with the high-frequency component of far-field earthquake motion in the ATC-63. On this basis, considering the spatial variability, the spatially related multi-point nonstationary ground motions are generated. The finite element modeling is carried out by using ANSYS software, and the artificial ground motion is input for incremental dynamic analysis. The probabilistic seismic demand model, combined with the division of pipeline ultimate failure state, of the relationship between PGV and the maximum strain of buried pipeline is established, and then the seismic vulnerability model is established for the buried pipeline with different pipe materials, pipe diameters, wall thickness and filled soil considering uncertainty. The model provides a theoretical basis for seismic vulnerability analysis in seismic risk assessment of buried pipelines across faults.