Effects of soil Properties and Fault Crossing Angle on the Behavior of Buried Pipeline

Buried pipeline system form a key part of global lifeline infrastructure and any significant disruption to the performance of these systems often lead to undesirable impact on regional business، economies or the living condition of citizens. In this paper the response of buried pipelines at fault crossings are studied. A fault movement can be resolved into an axial component، a lateral component in the horizontal plane، and a vertical component. Applying finite element method، the effect of various parameters such as anchored length، internal friction angle of surrounding soil، fault movement and fault crossing angle on the behavior of buried pipeline were studied. Nonlinear behavior for pipe and surrounding soil are assumed using beam-spring model. Results showed an increase in internal friction angle of surrounding soil increases strain and also normalized bending moment and axial force. Comparing bending moment at friction angle of 20° and 40° shows about 30% differences with certain crossing angle we can prevent producing large strain and bending moment on pipeline.