Abstract:An indoor splitting test was carried out to investigate the rock breaking effect which is influenced by the pre-cutting slot at borehole with an electro-hydraulic servo dynamic and static universal testing machine and some cube granite rock specimens. The directional control effect and the maximum splitting force at the moment of breaking were studied specifically in the test under different arrangement modes of pre-cutting slot,such as the setting or not,the direction(inclined slot along the diagonal direction and straight slot parallel to the upper surface boundary of specimen) and the length. Several experimental results were obtained as follows. (1) The pre-cutting slot can effectively control the initiation and propagation of crack and the extension direction of breaking surface,and can significantly inhibit the generation of secondary cracks. (2) Compared with the inclined slot,the straight slot can achieve better breaking directional control effect because it is less affected by the free surface. (3) The length of the pre-cutting slot possesses an obvious promotion effect in guiding the crack propagation and controlling the extension direction of the breaking surface,and this effect is positive correlation with the length of the slot. (4) The pre-cutting slot can reduce the maximum splitting force,and the maximum force shows a monotonically decreasing trend with the increase of the length of the slot. The above experimental conclusions will provide important practical guiding significance for improving rock breaking efficiency in non-blasting directional control rock splitting in the future.
刘媛媛,侯哲生,卜志凌. 预切槽对钻孔内撑式破岩效果影响的试验研究[J]. 岩石力学与工程学报, 2023, 42(S2): 4045-4053.
LIU Yuanyaun,HOU Zhesheng,BU Zhiling. Experimental study on influence of pre-cutting slot for breaking effect in rock splitting. , 2023, 42(S2): 4045-4053.
SHAN R L,HUANG B L,GAO W J,et al. Case studies of new technology application of quasi-parallel cut blasting in rock roadway drivage[J]. Chinese Journal of Rock Mechanics and Engineering,2011,30(2):224-232.
[2]
刘海卫. 钻孔劈裂器破岩机理的数值模拟研究[硕士学位论文][D]. 武汉:武汉理工大学,2007.(LIU Haiwei. Rock splitting mechanism numerical simulation analysis of the rock dril-splitter[M. S. Thesis][D]. Wuhan:Wuhan University of Technology,2007.(in Chinese))
[5]
LIU S,LI H,CHENG G. Numerical and experimental investigation on rock breaking performance with hydraulic splitter[J]. Tunnelling and Underground Space Technology,2020,96:103181.
[6]
ZHOU F,LIU S,HUANG J,et al. Experimental investigation of the fracture performance of hard rock with a single borehole by using a hydraulic splitter[J]. Arabian Journal for Science and Engineering,2021,46(11):10 655-10 666.
[9]
LI J H,LIN D N. Theoretical and experimental study on effects of empty hole in cut blasting[J]. Mining Research and Development,2007,27(5):75-77.
[12]
ZUO J,YANG R,MIN G,et al. Studies on directional breaking controlled theory of slotted cartridge blasting for rock[J]. Arabian Journal of Geosciences,2021,14:1928.
[15]
李 清,于 强,朱各勇,等. 不同药量的切缝药包双孔爆破裂纹扩展规律试验[J]. 岩石力学与工程学报,2017,36(9):2 205-2 212.(LI Qing,YU Qiang,ZHU Geyong,et al. Experimental study of crack propagation under two-hole slotted cartridge blasting with different amounts of charge[J]. Chinese Journal of Rock Mechanics and Engineering,2017,36(9):2 205-2 212.(in Chinese))
[16]
杨仁树,丁晨曦,杨立云,等. 含缺陷PMMA介质的定向断裂控制爆破试验研究[J]. 岩石力学与工程学报,2017,36(3):690-696.(YANG Renshu,DING Chenxi,YANG Liyun,et al. Experimental study on controlled direction fracture blasting on PMMA mediums with flaws[J]. Chinese Journal of Rock Mechanics and Engineering,2017,36(3):690-696.(in Chinese))
[19]
RATHORE S,BHANDARI S. Controlled fracture growth by blasting while protecting damages to remaining rock[J]. Rock Mechanics and Rock Engineering,2007,40(3):317-326.
[3]
白 瑛. 钻孔劈裂器作用下围岩应力场分析[硕士学位论文][D]. 武汉:武汉理工大学,2009.(BAI Ying. The distribution of stress on rock induced by the rock splitter[M. S. Thesis][D]. Wuhan:Wuhan University of Technology,2009.(in Chinese))
[1]
DE GRAAF W W,SPITERI W. A preliminary qualitative evaluation of a hydraulic splitting cylinder for breaking rock in deep-level mining[J]. Journal of the Southern African Institute of Mining and Metallurgy,2018,118(8):891-897.
[4]
闻德生,吕世君,朱学军,等. 液压劈裂机楔块组件的有限元模拟[J]. 系统仿真学报,2009,21(9):2 513-2 516.(WEN Desheng,LV Shijun,ZHU Xunjun,et al. Finite element simulation on wedge of hydraulic stone splitter[J]. Journal of System Simulation,2009,21(9):2 513-2 516.(in Chinese))
[7]
崔 松,刘送永,黄 举. 空孔作用下定向涨裂破岩试验研究[J]. 中南大学学报:自然科学版,2021,52(5):1 570-1 580.(CUI Song,LIU Songyong,HUANG Ju. Experimental research on directional fracturing and rock breaking under action of holes[J]. Journal of Central South University:Science and Technology,2021,52(5): 1 570-1 580.(in Chinese))
[8]
LI H,LIU S,CHENG G,et al. Numerical investigation on rock- fracturing mechanism by using splitter under hole assistance[J]. Shock and Vibration,2019. https://doi.org/10.1155/2019/4395729.
[13]
CHO S H,NAKAMURA Y,MOHANTY B,et al. Numerical study of fracture plane control in laboratory-scale blasting[J]. Engineering Fracture Mechanics,2008,75(13):3 966-3 984.
[14]
李 清,王平虎,杨仁树,等. 切槽孔爆破动态力学特征的动焦散线试验[J]. 爆炸与冲击,2009,29(4):413-418.(LI Qing,WANG Pinghu,YANG Renshu,et al. Dynamic caustic experiment on dynamic mechanical characteristics of slotted hole blasting[J]. Explosion and Shock Waves,2009,29(4):413-418.(in Chinese))
[17]
YANG R,WANG Y,XUE H,et al. Dynamic behavior analysis of perforated crack propagation in two-hole blasting[J]. Procedia Earth and Planetary Science,2012,5:254-261.
[11]
徐 颖,沈兆武,孟益平. 爆炸载荷作用下刻槽炮孔动态裂缝扩展规律[J]. 中国科学技术大学学报,2003,(2):61-67.(XU Ying,SHEN Zhaowu,MENG Yiping. Dynamic crack propagation law of grooved hole under explosion load[J]. Journal of University of Science and Technology of China,2003,(2):61-67.(in Chinese))
[18]
乔国栋,高 魁,郑明亮,等. 含控制孔预切槽爆破的裂隙扩展机制研究[J]. 工程爆破,2020,26(2):24-31.(QIAO Guodong,GAO Kui,ZHENG Mingliang,et al. Study on crack propagation mechanism of grooving blasting with controlled hole[J]. Engineering blasting,2020,26(2):24-31.(in Chinese))