顶管埋深及垮落体颗粒粒径对顶管力学性质的影响

    Influence of pipe jacking burial depth and caving body particle size on mechanical properties of pipe jacking

    • 摘要: 顶管救援法是通过将预制管道顶穿垮冒堵塞区,从而安全高效地形成应急生命通道。为研究不同顶管埋深及垮落体颗粒粒径条件下,垮落体在顶管作用下的宏细观力学性质,结合垮落体中顶管相似模拟试验和数值模拟试验,探讨了顶管埋深及垮落体颗粒粒径对顶管阻力和颗粒位移的影响,并进一步从配位数、力链及垮落体能量等角度对垮落体的宏细观参数进行了研究。结果表明:顶进阻力和颗粒位移整体随垮落体颗粒粒径、顶管埋深的增大而增大,位移区主要分为管口前方及后下方的挤压扰动区和管口正斜上方的剪切滑动区;配位数波动幅度和降幅差值随垮落体颗粒粒径和顶管埋深的增大而增大,管口斜前方的力链破坏且不断扩展,从而形成剪切滑动面;随垮落体颗粒粒径和顶管埋深增大,顶进过程中弹性势能、动能及耗散能整体呈正相关增长,顶进主要分为前期小应变扰动阶段和大应变剪切滑动阶段。

       

      Abstract: The pipe jacking rescue method is to form an emergency life passage safely and efficiently by jacking a prefabricated pipe through the caving and collapse blockage area. In order to study the macro-mesoscopic mechanical properties of the caving body under the action of pipe jacking under the conditions of different pipe jacking depths and particle sizes of the caving body, combining the similar simulation test and numerical simulation test of jacking pipe in caving body, the effects of pipe jacking burial depth and particle size of caving body on the resistance of jacking pipe and particle displacement are explored, and the macro-mesoscopic parameters of caving body are further investigated from the viewpoints of coordination number, force chain and energy of caving body. The results show that: the jacking resistance and particle displacement as a whole increase with the increase of particle size of caving body and pipe jacking burial depth, and the displacement zone is mainly divided into the extrusion and disturbance zone in front of and behind the pipe opening and the shear sliding zone directly above the pipe opening; the amplitude of the fluctuation of the coordination number and the difference of the drop increase with the increase of particle size of caving body and pipe jacking burial depth, and the force chain in front of the pipe opening is damaged and continuously expanded, thus forming a shear sliding surface; with the increase of particle size of caving body and pipe jacking burial depth, the elastic potential energy, kinetic energy and dissipation energy are positively correlated in the jacking process, and the jacking is mainly divided into the early small strain disturbance stage and large strain shear sliding stage.

       

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