Numerical and experimental investigation of rock breaking method under free surface by TBM disc cutter  

临空面下滚刀破岩方法数值模拟及试验研究（英文）

作　　者：ZHANG Xu-hui XIA Yi-min ZENG Gui-ying TAN Qing GUO Ben 张旭辉;夏毅敏;曾桂英;谭青;郭犇

机构地区：[1]State Key Laboratory of High Performance Complex Manufacturing(Central South University),Changsha 410083,China [2]School of Mechanical and Electrical Engineering,Central South University,Changsha 410083,China

出　　处：《Journal of Central South University》2018年第9期2107-2118,共12页中南大学学报（英文版）

基　　金：Project(2013CB035401)supported by the National Basic Research Program of China;Project(2012AA041803)supported by the National High-Technology Research and Development Program of China;Project(51475478)supported by the National Natural Science Foundation of China;Project(2015GK1029)supported by the Science and Technology Project of Strategic Emerging Industry in Hunan Province,China;Project(CX2017B048)supported by the Hunan Provincial Innovation Foundation For Postgraduate,China

摘　　要：To study the rock breaking method under the free surface induced by disc cutter,the rock breaking simulations were first conducted based on the discrete element method,and the dynamic process of rock breaking under the free surface was studied including stressed zone,crush zone,crack initiation and propagation.Then the crack propagation conditions,specific energy,etc.under different free surface distance(S)were also investigated combined with linear cutting experiments.The results show that the rock breaking process under the free surface induced by disc cutter is dominated by tension failure mode.There exists a critical S to promote crack propagation to free surface effectively.And this rock breaking method can improve the rock breaking force and breaking efficiency significantly when proper.为了研究临空面下滚刀新型破岩方法,采用离散元法建立了临空面下滚刀破岩模型,模拟了临空面下滚刀作用后密实核形成、裂纹起裂、裂纹扩展等动态过程,并结合线性切割实验研究了不同临空距下裂纹扩展模式、比能耗等变化规律。研究结果表明:临空面下滚刀破碎岩石过程以张拉破坏为主,存在一个临界临空距促使裂纹能有效扩展到临空面。当临空距合理时,临空面下滚刀新型破岩方法能显著降低破岩载荷并提升破岩效率。

关 键 词：free surface tunnel boring machine disc cutter rock breaking method 

分 类 号：U455.39[建筑科学—桥梁与隧道工程]