Study of the Mass Effect of a Complex Node of UnderGround Pipelines of Orthogonal Configuration Based on Real Earthquake Records

Abstract

AbstractThis paper considers the class of problems of dynamics of spatial systems of underground pipelines under the action of three-component seismic waves propagating in the ground on the basis of instrumental records of real earthquakes. For complex systems of underground pipelines as a method for solving the problems of nonstationary dynamics on spatial coordinates of pipelines the discretization by finite element method is used, and on time variable the implicit finite-difference scheme of Newmark type. The OX-axis is assigned as the direction of propagation of the three-component seismic waves. In order to account for the angle of incidence of seismic waves, the structure of the underground pipeline is rotated by a given angle relative to the direction of the OX axis. The conducted theoretical and computational-experimental studies solve the problem of assessment of stress–strain state of underground pipelines of complex orthogonal configuration under seismic effect arbitrarily directed to the main axes of the pipeline. In the calculations, a digitized seismogram record of the Chilean earthquake of January 24, 2016 was taken as a seismic waves. Multi-factor calculations were performed for different soil types and seismic waves incidence angles. The effect of a complex pipeline assembly on the dynamic process in the pipeline was investigated. Influence of boundary conditions and compound node on pipeline waves formation has been determined. Dangerous points of occurrence of maximum stresses in underground pipeline systems under the action of seismic waves propagating in space at an arbitrary angle of attack have been determined.KeywordsUnderground pipelineSeismic waveInteraction in the pipe-soil systemOrthogonal configurationNumerical method