The dynamic analysis of a steel pipeline under a seismic shock

This paper presents the analysis of the dynamic response of a steel overground pipeline to a strong seismic shock. The scientific motivation of this study was to identify the response of connections of steel pipeline sections to a strong seismic shock. A 105-metre-long steel pipeline was the subject of this investigation. A submodelling technique was used in the numerical analysis. All details, such as bolts, flanges and the support pillar, were modelled. Both models were subjected to non-uniform kinematic excitation. An actual seismic shock was used for the excitation of the pipeline. The excitation was applied to the structure as accelerations of particular supports acting in three dimensions. The three tested values of seismic wave velocity were 250m/s, 500m/s and 1500m/s; numerical calculation was conducted for each wave speed. During analyses, the normal stresses at representative points were calculated. The analysed points were located at the top, at the bottom and at the middle bolt. The values of stresses obtained for each analysis were compared. On the basis of this comparison, it can be noted that the stresses obtained for selected points reflected the complex state of stress in the connection. The bolt deformations also show the strong bending that occurred in connection elements.