格栅防护埋地管道的承载特性及设计参数分析

河北工业大学土木与交通学院,天津 300401

岩土工程; 埋地管道; 土工格栅; 极限承载力; 破坏模式; 静载; 数值模拟

Performance of bearing capacity and analysis of design parameters of buried pipelines with geogrid protection
LIU Kuan, XIAO Chengzhi, and WANG Zihan

School of Civil and Transportation Engineering, Hebei University of Technology, Tianjin 300401, P.R.China

geotechnical engineering; buried pipes; geogrid; ultimate bearing capacity; failure mode; static loading; numerical simulation

DOI: 10.3724/SP.J.1249.2019.01052

备注

为研究在土工格栅加筋防护埋地管道中筋材铺设和管周土体参数对防护管道性能的影响,基于有限元数值方法,分析静载作用下土体内摩擦角、筋材埋深、管道埋深和加载宽度等因素对管道力学与形变性能的影响. 结果表明,极限承载力随内摩擦角增大显著提高; 筋材埋深在加载板宽度的0.2倍左右时,加筋效果显著; 增大管道埋深,可显著提升极限承载力,同时降低管道变形; 减小加载宽度,可使破坏形式由管道变形失效转变为土体地基破坏,同时降低极限承载力; 格栅加筋效果与管道最终形变量的变化密切相关; 格栅加筋后与加筋前的极限承载力比值随土体内摩擦角和管道埋深的增大而减小,随加载宽度的增加先增后减.

In order to study the effect of parameters related with geogrid and surrounding soil of pipes on the performance of buried pipes reinforced by geogrids, the comprehensive analysis based on finite element method is carried out to investigate the effect of internal frictional angle of soil, embedment depths of geogrids, the buried depth of pipes, and width of loading plate on mechanical and deformation performances of the pipeline. The numerical results show that the ultimate bearing capacity of buried pipes increases remarkably with the increase of internal frictional angle. Optimum reinforcement effect can be obtained when buried depth equals to one fifth of the width of loading plate. Increasing buried depth of pipe can promote the ultimate bearing capacity evidently and alleviate deformation of pipes. Failure mode of buried pipes will change from deformation failure of pipe to foundation failure with the decrease of width of loading plate, and the ultimate bearing capacity will decrease. The effect of grid reinforcement is closely related to the change of the ultimate deformation of buried pipes. The ratio of ultimate bearing capacity of pipeline with grid reinforcement to that of pipeline without reinforcement decreases with the increase of frictional angle and buried depth and increases first and then decreases with increase of loading width.

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