Experimental study on pillar burst of sandstone under four-faces unloading conditions
LIU Dongqiao1，LING Kai1，2，LI Na1，2，HU Yi1，2，LIU Shuyong1，2，SUN Qingfeng1，2，SONG Wei3，XUE Yongqing3
(1. State Key Laboratory for Geomechanics and Deep Underground Engineering，China University of Mining and Technology，Beijing 100083，China；2. School of Mechanics and Civil Engineering，China University of Mining and Technology，Beijing 100083，China；3. China Railway 18th Bureau Group Tunnel Engineering Co.，Ltd.，Chongqing 400700，China)
Abstract：To explore the characteristics and mechanism of pillar burst at engineering sites，this paper uses cubic red sandstone to carry out pillar burst experiments under the condition of four-faces unloading and uniaxial compression conditions. The process of rock failure，acoustic emission(AE) characteristics，velocity field characteristics，debris characteristics and energy evolution characteristics were obtained. The results show that the failure process of uniaxial compression and pillar burst is similar，but the failure modes are different. The unloading process will aggravate the damage，and the higher the confining pressure，the greater the damage caused by unloading. The debris of uniaxial compression is massive and plate-shaped，while the debris of the pillar burst is long strips. The ejection velocity increases first and then decreases，reaching the peak at the moment of the burst，and the maximum velocity increases with the increase of the confining pressure. The distribution range of the AE spectrum is different，the spectrum is concentrated at 300–350 kHz when the confining pressure is low，and the spectrum is concentrated at 150–200 kHz when the confining pressure is high. The waveform energy of uniaxial compression distributes in complex multi-frequency bands，while the waveform energy of pillar burst distributes in single frequency band，and there is a good correspondence between different frequency bands and crack types.
[1] 齐庆新，陈尚本，王怀新，等. 冲击地压、岩爆、矿震的关系及其数值模拟研究[J]. 岩石力学与工程学报，2003，22(11)：1 852–1 858. (QI Qingxin，CHEN Shangben，WANG Huaixin，et al. Study on the relations among coal bump，rockburst and mining tremor with numerical simulation[J]. Chinese Journal of Rock Mechanics and Engineering，2003，22(11)：1 852–1 858.(in Chinese))
[2] 姜耀东，潘一山，姜福兴，等. 我国煤炭开采中的冲击地压机制和防治[J]. 煤炭学报，2014，39(2)：205–213.(JIANG Yaodong，PAN Yishan，JIANG Fuxing，et al. State of the art review on mechanism and prevention of coal bumps in China[J]. Journal of China Coal Society，2014，39(2)：205–213.(in Chinese))
[3] 钱七虎. 岩爆、冲击地压的定义、机制、分类及其定量预测模型[J]. 岩土力学，2014，35(1)：1–6.(QIAN Qihu. Definition，mechanism，classification and quantitative forecast model for rockburst and pressure bump[J]. Rock and Soil Mechanics，2014，35(1)：1–6.(in Chinese))
[4] JIANG Q，FENG X T，XIANG T B，et al. Rockburst characteristics and numerical simulation based on a new energy index：A case study of a tunnel at 2 500 m depth[J]. Bulletin of Engineering Geology and the Environment，2010，69(3)：381–388.
[5] KAISER P K，CAI M. Design of rock support system under rockburst condition[J]. Journal of Rock Mechanics and Geotechnical Engineering，2012，4(3)：215–227.
[6] MARTINA C D，MAYBEE W G. The strength of hard-rock pillars[J]. International Journal of Rock Mechanics and Mining Sciences，2000，37(8)：1 239–1 246.
[7] ESTERHUIZEN G S，DOLINAR D R，ELLENBERGER J L. Pillar strength in underground stone mines in the United States[J]. International Journal of Rock Mechanics and Mining Sciences，2011，48(1)：42–50.
[8] 何满潮，苗金丽，李德建，等. 深部花岗岩试样岩爆过程实验研究[J]. 岩石力学与工程学报，2007，26(5)：865–876.(HE Manchao，MIAO Jinli，LI Dejain，et al. Experimental study on rockburst processes of granite specimen at great depth[J]. Chinese Journal of Rock Mechanics and Engineering，2007，26(5)：865–876.(in Chinese))
[9] 何满潮，李杰宇，任富强，等. 不同层理倾角砂岩单向双面卸荷岩爆弹射速度实验研究[J]. 岩石力学与工程学报，2021，40(3)：433–447.(HE Manchao，LI Jieyu，REN Fuqiang，et al. Experimental investigation on rockburst ejection velocity of unidirectional double-face unloading of sandstone with different bedding angles[J]. Chinese Journal of Rock Mechanics and Engineering，2021，40(3)：433–447.(in Chinese))
[10] HE M C，REN F Q，LIU D Q，et al. Experimental study on strain burst characteristics of sandstone under true triaxial loading and double faces unloading in one direction[J]. Rock Mechanics and Rock Engineering，2021，54(1)：149–171.
[11] 何满潮，任富强，宫伟力，等. 基于双目立体视觉技术的岩爆碎屑弹射速度理论修正模型[J]. 岩石力学与工程学报，2017，36(10)：2 341–2 346.(HE Manchao，REN Fuqiang，GONG Weili，et al. Modified model for ejection velocity of rock burst fragments based on binocular stereovision technology[J]. Chinese Journal of Rock Mechanics and Engineering，2017，36(10)：2 341–2 346.(in Chinese))
[12] 何满潮，任富强，宫伟力，等. 应变型岩爆物理模拟实验过程的温度特征[J]. 中国矿业大学学报，2017，46(4)：692–698.(HE Manchao，REN Fuqiang，GONG Weili，et al. Temperature characteristics during physical simulation test of strain burst[J]. Journal of China University of Mining and Technology，2017，46(4)：692–698.(in Chinese))
[13] 苏国韶，蒋剑青，冯夏庭，等. 岩爆弹射破坏过程的试验研究[J]. 岩石力学与工程学报，2016，35(10)：1 990–1 999.(SU Guoshao，JIANG Jianqing，FENG Xiating，et al. Experimental study of ejection process in rockburst[J]. Chinese Journal of Rock Mechanics and Engineering，2016，35(10)：1 990–1 999.(in Chinese))
[14] 苏国韶，燕思周，闫召富，等. 真三轴加载条件下岩爆过程的声发射演化特征[J]. 岩土力学，2019，40(5)：1 673–1 682.(SU Guoshao，YAN Sizhou，YAN Zhaofu，et al. Evolution characteristics of acoustic emission in rockburst process under true-triaxial loading conditions[J]. Rock and Soil Mechanics，2019，40(5)：1 673–1 682.(in Chinese))
[15] 苏国韶，胡李华，冯夏庭，等. 低频周期扰动荷载与静载联合作用下岩爆过程的真三轴试验研究[J]. 岩石力学与工程学报，2016，35(7)：1 309–1 322.(SU Guoshao，HU Lihua，FENG Xiating，et al. True triaxial experimental study of rockburst process under low frequency cyclic disturbance load combined with static load[J]. Chinese Journal of Rock Mechanics and Engineering，2016，35(7)：1 309–1 322.(in Chinese))
[16] 刘冬桥，刘赫赫，王 炀，等. 钻孔卸压防治岩爆实验及破坏特征研究[J]. 岩石力学与工程学报，2023，42(1)：100–114.(LIU Dongqiao，LIU Hehe，WANG Yang，et al. Experimental study on drilling pressure relief for rockburst prevention and its failure characteristics[J]. Chinese Journal of Rock Mechanics and Engineering，2023，42(1)：100–114.(in Chinese))
[17] 马艾阳，伍法权，沙 鹏，等. 锦屏大理岩真三轴岩爆试验的渐进破坏过程研究[J]. 岩土力学，2014，35(10)：2 868–2 874.(MA Aiyang，WU Faquan，SHA Peng，et al. Progressive failure of Jinping marble in true triaxial rockburst test[J]. Rock and Soil Mechanics，2014，35(10)：2 868–2 874.(in Chinese))
[18] 王春来，廖泽锋，李长峰，等. 花岗岩岩爆声发射时空熵值动态特征实验研究[J]. 采矿与安全工程学报，2019，36(3)：626–633.(WANG Chunlai，LIAO Zefeng，LI Changfeng，et al. Experimental investigation of dynamic characteristics of AE spatio-temporal entropy for granitic rockburst[J]. Journal of Mining and Safety Engineering，2019，36(3)：626–633.(in Chinese))
[19] 赵光明，刘崇岩，许文松，等. 扰动诱发高应力卸荷岩体破坏特征实验研究[J]. 煤炭学报，2021，46(2)：412–423.(ZHAO Guangming，LIU Chongyan，XU Wensong，et al. Experimental study on the failure characteristics of high stress unloading rock mass induced by disturbance[J]. Journal of China Coal Society，2021，46(2)：412–423.(in Chinese))
[20] 何满潮，刘冬桥，宫伟力，等. 冲击岩爆试验系统研发及试验[J]. 岩石力学与工程学报，2014，33(9)：1 729–1 739.(HE Manchao，LIU Dongqiao，GONG Weili，et al. Development of a testing system for impact rockbursts[J]. Chinese Journal of Rock Mechanics and Engineering，2014，33(9)：1 729–1 739.(in Chinese))
[21] 刘冬桥，韩子杰，王春光，等. 单向、双向和三向扰动诱发岩爆碎屑特征实验研究[J]. 中南大学学报：自然科学版，2021，52(8)：2 793–2 804.(LIU Dongqiao，HAN Zijie，WANG Chunguang，et al. Experimental study of fragment characteristics of rockburst induced by uni-directional，bi-directional and tri-directional disturbances[J]. Journal of Central South University：Science and Technology，2021，52(8)：2 793–2 804.(in Chinese))
[22] 刘冬桥，胡天祥，王 炀，等. 动载频率对砂岩冲击岩爆影响的实验研究[J]. 岩石力学与工程学报，2022，41(7)：1 310–1 324.(LIU Dongqiao，HU Tianxiang，WANG Yang，et al. Experimental study of the effect of loadig frequency on the impact rockburst of sandstone[J]. Chinese Journal of Rock Mechanics and Engineering，2022，41(7)：1 310–1 324.(in Chinese))
[23] 王 炀，何满潮，刘冬桥，等. 深部椭圆形洞室围岩冲击岩爆实验研究[J]. 岩石力学与工程学报，2021，40(11)：2 214–2 228.(WANG Yang，HE Manchao，LIU Dongqiao，et al. Experimental study on impact rockburst of surrounding rock in deep elliptical caverns[J]. Chinese Journal of Rock Mechanics and Engineering，2021，40(11)：2 214–2 228.(in Chinese))
[24] 宫凤强，罗 勇，刘冬桥. 深部直墙拱形隧洞围岩板裂破坏的模拟试验研究[J]. 岩土工程学报，2019，41(6)：1 091–1 110.(GONG Fengqiang，LUO Yong，LIU Dongqiao. Simulation tests on spalling failure in deep straight-wall-top-arch tunnels[J]. Chinese Journal of Geotechnical Engineering，2019，41(6)：1 091–1 110.(in Chinese))
[25] 宫凤强，伍武星，李天斌，等. 深部硬岩矩形隧洞围岩板裂破坏的试验模拟研究[J]. 岩土力学，2019，40(6)：2 085–2 098.(GONG Fengqiang，WU Wuxing，LI Tianbin，et al. Simulation experimental study of spalling failure of surrounding rock of rectangular tunnel of deep hard rock[J]. Rock and Soil Mechanics，2019，40(6)：2 085–2 098.(in Chinese))
[26] HE M C，LI J Y，LIU D Q，et al. A novel true triaxial apparatus for simulating strain bursts under high stress[J]. Rock Mechanics and Rock Engineering，2021，54(2)：759–775.
[27] 黄润秋，黄 达. 卸荷条件下花岗岩力学特性试验研究[J]. 岩石力学与工程学报，2008，27(11)：2 205–2 213.(HUANG Runqiu，HUANG Da. Experimental research on mechanical properties of granites under unloading condition[J]. Chinese Journal of Rock Mechanics and Engineering，2008，27(11)：2 205–2 213.(in Chinese))
[28] LI X B，DU K，LI D Y. True triaxial strength and failure modes of cubic rock specimens with unloading the minor principal stress[J]. Rock Mechanics and Rock Engineering，2015，48(6)：2 185–2 196.
[29] WANG C L，CAO C，LIU Y B，et al. Experimental investigation on synergetic prediction of rockburst using the dominant?frequency entropy of acoustic emission[J]. Natural Hazards，2021，108(3)：3 253–3 270.
[30] CAI M，KAISER P K MORIOKA H，MINAMI M，et al. FLAC/PFC coupled numerical simulation of AE in large-scale underground excavations[J]. International Journal of Rock Mechanics and Mining Science，2007，44：550–564.
[31] 朱权洁，姜福兴，于正兴，等. 爆破震动与岩石破裂微震信号能量分布特征研究[J]. 岩石力学与工程学报，2012，31(4)：723–730.(ZHU Quanjie，JIANG Fuxing，YU Zhengxing，et al. Study on energy distribution characters about blasting vibration and rock fracture microseismic signal[J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(4)：723–730.(in Chinese))
[32] ENOMOTO Y，HASHIMOTO H. Emission of charged particles from indentation fracture of rocks[J]. Nature，1990，346(6285)：641–643.
[33] GROSSE C，OHTSU M. Acoustic emission testing[M]. Berlin Heidelberg：Springer，2008：47–48.
[34] 谢和平，鞠 杨，黎立云. 基于能量耗散与释放原理的岩石强度与整体破坏准则[J]. 岩石力学与工程学报，2005，24(17)：3 003–3 010. (XIE Heping，JU Yang，LI Liyun. Criteria for strength and structural failure of rocks based on energy dissipation and energy release principles[J]. Chinese Journal of Rock Mechanics and Engineering，2005，24(17)：3 003–3 010.(in Chinese))
[35] HE M C，XIA H M，JIA X N，et al. Studies on classification，criteria and control of rockbursts[J]. Journal of Rock Mechanics and Geotechnical Engineering，2012，4(2)：97–114.
[36] 陈景涛，冯夏庭. 高地应力下岩石的真三轴试验研究[J]. 岩石力学与工程学报，2006，25(8)：1 537–1 543.(CHEN Jingtao，FENG Xiating. True triaxial experimental study on rock with high geostress[J]. Chinese Journal of Rock Mechanics and Engineering，2006，25(8)：1 537–1 543.(in Chinese))
[37] CHANG C，HAIMSON B C. True triaxial strength and deformability of the KTB deep hole amphibolite[J]. Journal of Geophysical Research，2000，105(8)：18 999–19 031.
[38] SI X F，GONG F Q. Strength-weakening effect and shear-tension failure mode transformation mechanism of rockburst for fine-grained granite under triaxial unloading compression[J]. International Journal of Rock Mechanics and Mining Sciences，2020，131：104347.
[39] ZHAO H G，SONG Z L，ZHANG D M，et al. True triaxial experimental study on mechanical characteristics and energy evolution of sandstone under various loading and unloading rates[J]. Geomechanics and Geophysics for Geoenergy and Georesources，2021，7(1)：22.
[40] ZHAI S B，SU G S，YIN S D，et al. Rockburst characteristics of several hard brittle rocks：A true triaxial experimental study[J]. Journal of Rock Mechanics and Geotechnical Engineering，2020，12(2)：279–296.
[41] 苏国韶，陈智勇，尹宏雪，等. 高温后花岗岩岩爆的真三轴试验研究[J]. 岩土工程学报，2016，38(9)：1 586–1 594.(SU Guoshao，CHEN Zhiyong，YIN Hongxue，et al. True triaxial tests on rockburst of granite after high temperatures[J]. Chinese Journal of Geotechnical Engineering，2016，38(9)：1 586–1 594.(in Chinese))
[42] JIANG J Q，SU G S，ZHANG X H，et al. Effect of initial damage on remotely triggered rockburst in granite：an experimental study[J]. Bulletin of Engineering Geology and the Environment，2020，79：3 715–3 194.
2023, Vol. 42 
