Research On Longitudinal Mechanical Characteristics Of Pipelines Buried In Soft Soil Under Vertical Loads

With the increase of urbanization process, the construction of pipelines becomes more and more broad. Under the loads of upside soil and other loads, those pipelines buried in soft soil are prone to produce longitudinal bending, its influence will cause pipelines to produce breaks in the weakest parts, which will lead to leakage and even blowout. Therefore, in this paper, the longitudinal mechanical characteristics of buried pipelines under vertical loads are calculated and analyzed.Based on the Boussinesq method, the mechanical characteristics of buried pipelines under vertical loads are calculated and analyzed, and the additional vertical and horizontal load on pipelines was obtained. Further, the curve-fitting method was used to predigest the distribution of additional load, both vertical and horizontal. According to the short beam theory of Winkler elastic foundation, the deformation, shearing force, bending moment of the pipeline were devaluated, considering two different boundary condition.Using ABAQUS calculate the mechanical characteristics of buried pipelines under the long-term evenly distributed load and impulsive load. When the load is long-term evenly distributed, the influences of each relevant factor, i.e. pipeline depth, diameter, deformation module of foundation, Poisson ratio of soil, the magnitude and the locality of the load, toward Mises stress , horizontal and vertical displacement of pipelines are discussed. When the load is impulsive, the influences of each relevant factor, i.e. the magnitude, the locality and the effect time of the load , toward Mises stress , horizontal and vertical displacement of the middle point of pipelines are discussed.According to the results obtained from the analyses, pipelines protection measures, which can be adopted in project design and construction, are put forward.The method and results of this paper will provide certain theoretical method and reference for continuous research on mechanical characteristics of buried pipelines in future.