滚刀作用下北山花岗岩裂纹扩展模式研究
发布时间：2018-07-17 08:24
【摘要】：自上世纪50年代中期以来,岩石隧道掘进机以其施工环境友好、施工速度快、对围岩的扰动小以及长隧道施工的经济效益显著等优点,已广泛应用于各国地下工程的建设。对于高放废物处置库而言,围岩损伤特征是影响其长期稳定性及运行安全性的重要因素,围岩损伤的产生与演化和诸多因素相关,以TBM法为主的机械开挖方法具有围岩扰动小等优点,成为高放废物处置库和地下实验室大量高标准井巷工程选用的主要开挖方法。因此,对TBM刀盘滚刀作用下的围岩破裂和损伤特性以及节理间距对破岩的影响进行研究,是研究处置库的损伤分布情况以及后续的核素运移模式的基础,具有重要意义。本文结合室内全尺寸滚刀线性切割破岩实验,采用荧光法研究了盘形滚刀作用下不同刀间距(70mm、80mm、90mm、100mm)对北山花岗岩裂纹扩展特征的影响规律。针对滚刀下岩样破碎特征,借助CorelDraw和Image J软件对裂纹荧光图进行分区及统计分析,并与岩样各区的波速损伤指标进行对比。另外,结合室内全尺寸滚刀线性切割破岩实验,研究了不同节理间距对TBM滚刀力及破坏模式的影响。研究发现,同一刀间距作用下岩样各区的破碎程度存在较大的差异;不同刀间距作用下,岩样各区裂纹扩展的深度、长度及面积随着刀间距的增大呈现增大的趋势,且各区所占的比例随刀间距变化而不同。针对北山花岗岩,刀间距为70~100mm时,围岩损伤范围小于50mm。裂纹扩展模式对TBM破岩效率、破岩损伤以及岩片形状有显著影响。主要从三向力、裂纹的扩展模式和岩片等角度分析了节理间距对滚刀破岩的影响。结果表明:节理间距100mm的岩体切入所需要的推力小于完整岩石的推力,节理间距400mm的岩体破岩过程中推力有一个突变的过程。节理间距100mm岩体滚刀作用下存在两种破坏模式,节理间距400mm的岩体破岩过程则包括了正常破岩和节理面影响破岩两个过程,并且节理对了竖向主裂纹向节理面扩展有加剧的作用。节理面下方岩石较完整,节理面阻碍了裂纹朝节理面下方岩石传播。
[Abstract]:Since the middle of 1950s, rock tunnel tunneling machine has been widely used in the construction of underground projects in various countries because of its advantages of friendly construction environment, fast construction speed, small disturbance to surrounding rock and remarkable economic benefits of long tunnel construction. The damage characteristics of surrounding rock is an important factor affecting the long-term stability and operation safety of HLW, and the generation of surrounding rock damage is related to evolution and many factors. The mechanical excavation method based on TBM method has the advantages of small disturbance of surrounding rock and so on. It has become the main excavation method for high-level radioactive waste disposal storehouse and a large number of underground laboratory high standard shaft and roadway projects. Therefore, it is of great significance to study the fracture and damage characteristics of surrounding rock and the effect of joint spacing on rock breaking under the action of TBM cutter hob, which is the basis of studying the damage distribution in the repository and the subsequent nuclide migration model. In this paper, the influence of different cutter spacing (70mm / 80mm / 90mm / 100mm) on crack propagation characteristics of Beishan granite under the action of disk hob is studied by fluorescence method combined with laboratory experiments of linear cutting rock breaking with full-scale hob. According to the characteristics of rock sample fragmentation under hob, the crack fluorescence map is divided and statistically analyzed by using CorelDraw and Image J software, and the wave velocity damage index of rock sample is compared with that of rock sample. In addition, the influence of different joint spacing on the force and failure mode of TBM hob is studied. It is found that there is a great difference in the degree of fragmentation of rock samples under the same knife spacing, and the depth, length and area of crack propagation in rock samples show a trend of increasing with the increase of tool spacing, and the depth, length and area of crack propagation in rock samples are increased with the increase of blade spacing. And the proportion of each region varies with the distance between knives. For Beishan granite, the damage range of surrounding rock is less than 50 mm when the tool spacing is 70~100mm. The crack propagation model has a significant effect on the rock breaking efficiency, rock breaking damage and the shape of rock fragments of TBM. The influence of joint spacing on the breaking rock of hob is analyzed from the angles of triaxial force, crack propagation model and rock sheet. The results show that the thrust of the rock mass with joint spacing 100mm is less than that of the whole rock mass, and the thrust of the rock mass with joint spacing 400mm has a sudden process. There are two failure modes under the action of joint-spacing 100mm rock hob. The rock mass breaking process of joint-spacing 400mm includes two processes: normal rock breaking and joint surface influencing rock breaking. And the joint can accelerate the propagation of the vertical main crack to the joint surface. The rock below the joint surface is relatively complete, and the joint surface prevents the crack from spreading to the rock below the joint surface.
【学位授予单位】：北京工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.31;U456
，
本文编号：2129789
[Abstract]:Since the middle of 1950s, rock tunnel tunneling machine has been widely used in the construction of underground projects in various countries because of its advantages of friendly construction environment, fast construction speed, small disturbance to surrounding rock and remarkable economic benefits of long tunnel construction. The damage characteristics of surrounding rock is an important factor affecting the long-term stability and operation safety of HLW, and the generation of surrounding rock damage is related to evolution and many factors. The mechanical excavation method based on TBM method has the advantages of small disturbance of surrounding rock and so on. It has become the main excavation method for high-level radioactive waste disposal storehouse and a large number of underground laboratory high standard shaft and roadway projects. Therefore, it is of great significance to study the fracture and damage characteristics of surrounding rock and the effect of joint spacing on rock breaking under the action of TBM cutter hob, which is the basis of studying the damage distribution in the repository and the subsequent nuclide migration model. In this paper, the influence of different cutter spacing (70mm / 80mm / 90mm / 100mm) on crack propagation characteristics of Beishan granite under the action of disk hob is studied by fluorescence method combined with laboratory experiments of linear cutting rock breaking with full-scale hob. According to the characteristics of rock sample fragmentation under hob, the crack fluorescence map is divided and statistically analyzed by using CorelDraw and Image J software, and the wave velocity damage index of rock sample is compared with that of rock sample. In addition, the influence of different joint spacing on the force and failure mode of TBM hob is studied. It is found that there is a great difference in the degree of fragmentation of rock samples under the same knife spacing, and the depth, length and area of crack propagation in rock samples show a trend of increasing with the increase of tool spacing, and the depth, length and area of crack propagation in rock samples are increased with the increase of blade spacing. And the proportion of each region varies with the distance between knives. For Beishan granite, the damage range of surrounding rock is less than 50 mm when the tool spacing is 70~100mm. The crack propagation model has a significant effect on the rock breaking efficiency, rock breaking damage and the shape of rock fragments of TBM. The influence of joint spacing on the breaking rock of hob is analyzed from the angles of triaxial force, crack propagation model and rock sheet. The results show that the thrust of the rock mass with joint spacing 100mm is less than that of the whole rock mass, and the thrust of the rock mass with joint spacing 400mm has a sudden process. There are two failure modes under the action of joint-spacing 100mm rock hob. The rock mass breaking process of joint-spacing 400mm includes two processes: normal rock breaking and joint surface influencing rock breaking. And the joint can accelerate the propagation of the vertical main crack to the joint surface. The rock below the joint surface is relatively complete, and the joint surface prevents the crack from spreading to the rock below the joint surface.
【学位授予单位】：北京工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.31;U456
，
本文编号：2129789
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