Abstract: Based on the theory of elastic-plastic mechanics and finite element analysis method, the analysis model of buried gathering pipeline under the action of rock collapse is established, and the influence law of different factors on the stress of buried gathering pipeline under the action of rock collapse is studied. The results show that the impact load increases exponentially with the increase of the side length of the block. When the side length of the cube changes by 1.4 m, the impact load can be changed by 22.4 MPa. Operation pressure, temperature and pipeline laying slope have little influence on pipeline wall stress, while impact load and corrosion are the main factors affecting the safety of buried gathering and transportation pipelines. When the impact load is greater than 10.5 MPa, the pipe will enter the plastic deformation zone. When the rock collapse impact load is large, the maximum equivalent stress on the pipe wall decreases with the increase of the pipe diameter thickness ratio. When the diameter thickness ratio changes 3.8, the maximum equivalent stress on the pipe wall can be reduced by 44 MPa; when the rock collapse impact load is small, the maximum equivalent stress on the pipe wall appears a minimum point.

Key words: rock collapse, buried pipeline, finite element method, maximum equivalent stress