Determination of optimal Distance of Anchor-blocks in Buried Oil Pipelines Considering the Effects of the Dynamic Soil-Pipe Interaction

In this paper, by using direct modeling of the soil-pipe line system using finite element modelling (FEM) in OpenSEES software and integration with the particle swarm optimization (PSO) algorithm which is provided in MATLAB software in the reciprocating method, which is repeated in enough epochs, the optimal intervals of the anchor blocks has been gained and the effect of different parameters of pipe diameter, pipe length, burial depth, different soils and different earthquake stimuli on the seismic behavior of pipes having anchor blocks investigated.The results show that the change in the depth of the burial and the diameter of the pipe has no effect on the anchor block optimal intervals. Also, increasing the length of the pipe will cause to increase the proposed optimal distance between the anchor blocks. The levels of earthquake hazard and soil type, as well as the length of the pipe, are factors affecting on the distance between the anchor blocks. The simultaneous effect of softening the soil and increasing the level of the earthquake hazard increases the distance between the anchor blocks.