Abstract

This paper describes how pipelines are often located in seismic unstable slopes where earthquake-induced movements may cause their collapse. Thus, the analysis of the soil-pipe interaction plays a large role for the seismic hazard prevision. This paper deals with an analytical approach for the study of the interaction phenomena occurring between pipe and surrounding soil when pipelines cross unstable slopes. Some analytical solutions are presented in order to evaluate displacement, lateral deflection and bending moment distribution along the pipe. The Newmark method extended to a 3-D analysis was used to evaluate the permanent earthquake-induced displacement in slope due to ground motion. The aim is the prevention of unacceptable conditions for the pipeline and to avoid the pipe failure. Field and laboratory tests confirm that the soil shows a non-linear behavior even under low loading: so a non-linear behavior for the soil-pipe interaction should be considered to take into account the plastic response. The non-linear model used in the analysis and the results obtained, with particular reference to the influence of the soil modeling are presented in the paper. Document type: Part of book or chapter of book