土工格栅防护浅埋HDPE管道的力学性能数值分析

Numerical modeling on mechanical properties of shallow-buried HDPE pipe protected with geogrids

为了研究不同加筋防护形式下埋地管道力学性能的差异,借助ABAQUS软件对静载作用下采用土工格栅防护浅埋HDPE管道的效果进行了数值模拟。结果表明:仅在管道上方加筋时其极限承载力可提高约0.7倍,而采用倒U形或环包式加筋时可提高约2.0倍;格栅加筋可有效抑制管道变形,且随着筋材数量的增加,埋地管道破坏形式由加载板地基破坏变为管道变形比达到限值;管道发生形变后,其外表面在管顶和管底区域(300°~60°和120°~240°范围)内受压,在管肩与管腰之间的区域(60°~120°和240°~300°范围)内受拉;地表荷载较大时,土工格栅的加筋效果较为明显,且对管周土体的应力影响显著;对于浅埋管道,倒U形防护形式的效果最佳。

In order to figure out the differences of mechanical properties of buried pipes under different patterns of reinforcement protection, shallowly buried HDPE pipes reinforced with geogrids under static load was numerically analyzed using ABAQUS software. The results showed that the ultimate bearing capacity of the pipes can increase by about 0.7times when it is only reinforced above the pipe. However, it can increase by about 2.0 times when it is reinforced with inverted U-shaped or ring-wrapped reinforcement. Geogrid reinforcement can effectively ward the pipe deformation, and with the increase of the number of reinforcements, the failure mode of buried pipe changes from the failure of loading plate foundation to overdeformed pipe. After the deformation of pipe occurs, the outside of the pipe is compressed in the top and bottom regions(the range of 300°~60° and 120°~240°), and it is tensioned in the regions between shoulder and waist(the range of 60°~120° and 240°~300°). When the surface load is larger, the reinforcement effect of geogrid is more significant, and the stress of the soil around the pipe is significantly affected. For shallow buried pipes, inverted Ushaped protection has the best performance.