Earthquake Response Analysis On Buried Steel Pipeline

Recently, as the development of the economy, the underground pipes are getting more. With the influence of the earthquake, the underground pipes have different vibration characteristics comparing with the structures above ground. The necessity of the seismic research to the underground pipes is known through the investment and analysis of the underground pipes earthquake damages. So, it is very important to carry out the analysis of the earthquake responses.In this paper, the characteristic of the earthquake damage is firstly analyzed. According to the investment of the earthquake damages, the damage modes of the underground pipes are summed up as well as the major effective factors. With the established pipe-earth interactive3D actual model, earthquake response analysis on the underground steel pipes is carried out. The main tasks are as follows:1. establishment of the3D actual model of the pipe-earth interactionIn the underground entire pipe-earth model, the pipe is modeled with shell element, and the soil body is modeled with the entity element. The interaction is modeled with contact element. The model is established with ADINA. The model is considered as the material non-linearity, geometrical non-linearity. Then the related parameters are chosen and the boundary conditions are set.2. Earthquake response analysis on buried steel pipelineFirstly, static analysis of the buried steel pipeline is carried out. Then the Elcentro displacement wave is input from X、Y、Z three directions separately and simulation research is carried out. The results show that:Under the earthquake, when the seismic wave is input from X direction, the damage to the underground pipelines is the worst.Secondly, the influence of the pipeline’s anti-seismic performance is studied with changing three parameters:the friction coefficient between the pipelines and the earth, the thickness of the pipes and the depth of the pipes. The computation results show that:Under earthquake, when the friction coefficient of pipe-earth is0.3, the axial stress and the other additional stresses of the pipeline are the highest. The thicker the pipelines’ wall is, the lower the created each stresses. The stress of the pipeline will increase with the increasing depth of the overburden, which is bad for the pipelines’anti-earthquake. So the pipelines should be buried as shallow as possible.