全断面隧道掘进机滚刀预切槽破岩数值模拟  

Numerical Simulation on the Rock Fragmentation by Tunnel Boring Machine Disc Cutters Assisted by Pre-Cut Grooves

作　　者：耿麒 卢智勇 张泽宇[1,2] 汪学斌 马茂勋[1] 叶敏 GENG Qi;LU Zhiyong;ZHANG Zeyu;WANG Xuebin;MA Maoxun;YE Min(National Engineering Laboratory of Highway Maintenance Equipment,Chang’an University,Xi’an 710064,China;Post-Doctoral Research Center,Tibet Tianlu Co.Ltd.,Lasa 850000,China)

机构地区：[1]长安大学公路养护装备国家工程实验室,西安710064 [2]西藏天路股份有限公司博士后工作站,拉萨850000

出　　处：《西安交通大学学报》2021年第9期9-19,共11页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金青年科学基金资助项目(51805042);陕西省高校科协青年人才托举计划资助项目(20200411);长安大学中央高校基本科研业务费专项资金资助项目(300102251201)。

摘　　要：针对现有全断面隧道掘进机(TBM)滚刀破岩研究对预切槽破岩的破坏原理阐释不深、切槽影响规律揭示不明的问题,构建了基于泰森多边形算法的等效晶质岩石材料的颗粒簇离散元模型,分析了不同预切槽辅助下滚刀贯入岩石的密实核演化、裂纹扩展和成碴破坏等过程,并进行小型刀具静压破岩试验验证了数值模型的可靠性。进行数值模拟,研究了切槽角度、位置、间距等结构参数对裂纹分布、破岩载荷和贯入比能的影响规律。仿真结果表明:基于预切槽弱化围岩和密实核传力双重机制的错缝预切槽破岩方法可极大提高硬岩破碎效率,“窄直切槽、错缝切削、滚刀中置”是最优的切槽结构及排布模式,建议预切槽开口角度为0°、滚刀贯入点和预切槽交错布置且滚刀位于相邻预切槽正中、预切槽最优间距为80 mm。该研究为TBM滚刀破岩机理研究提供了有效手段,为探究辅助滚刀破岩的预切槽合理结构提供了理论依据。In view of the problems existing in the research on rock fragmentation by TBM(tunnel boring machine)disc cutters that the rock failure mechanism under pre-cut groove condition has not been investigated in depth,and the influence of the pre-cut groove structure on rock fragmentation performance has not been clearly revealed,a discrete element model of equivalent crystalline rock material based on Thiessen polygon algorithm was built,and the processes of dense core evolution,crack propagation and rock fragmentation during cutter penetration assisted by different pre-cut grooves were analyzed and the numerical model was verified by small scaled rock penetration tests.Numerical simulations were carried out to study the influence of pre-cut groove structural parameters such as notch angle,location and spacing,on the crack distribution,rock breaking load and penetration specific energy.The simulation results show that the rock breaking efficiency can be greatly improved using the staggered groove assisted approach whose critical techniques are rock weakening by pre-cut grooves and load transfer by dense cores.The optimal layout mode of the pre-cut grooves is summarized as“narrow straight,staggered distributed,and middle placed”.It means that the notch angle of the grooves is suggested to be 0°,the cutter penetration points and the pre-cut grooves are arranged in a staggered layout and the cutter penetration point is located at the center of two adjacent pre-cut grooves,and the optimal groove spacing is suggested to be 80 mm.This study suggests an effective approach for the study of rock breaking mechanism of TBM disc cutters,and provides a theoretical basis for exploring the reasonable structure of pre-cut grooves.

关 键 词：全断面隧道掘进机 滚刀 预切槽 颗粒簇离散元 

分 类 号：TU94[建筑科学—建筑技术科学]