Influence of different faults on stress performance of buried pipelines

In order to study the stress performance of buried pipelines under different types of faulting, the soilbox test device was made to simulate the fault movement. Then, the strain distribution and overall deformation characteristics of buried pipelines under fault movement were obtained, the variation characteristics of axial strain and vertical displacement of pipelines with fault movement were analyzed, the influence rules of fault movement, pipe buried depth, pipe diameter and fault dip, etc. on the stress performance of buried pipelines were explored. The FEM method was used to conduct numerical simulation and its results were compared with test results. The results show that, within the parameter range of the test, the axial strain of the pipeline increases with the increase of fault movement and buried depth. Larger diameter pipelines will have stronger deformation resistance capability. When the fault dip is less than 90°, the axial peak tensile strain of the pipeline will be larger than the peak compressive strain, indicating that the tensile stress of the pipeline is dominant in this case. Similarly, when the fault dip exceeds 90°, the axial peak tensile strain of the pipeline will be smaller than the peak compressive strain, indicating a dominant compressive strain in that case. For strike-slip faults, the axial strain of the pipeline is approximately distributed in central symmetry, and the deformation on both sides tends to be consistent. Strike-slip fault has a minimal influence on the pipeline strain, followed by normal fault, and reverse fault has the greatest influence on the pipeline strain.