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| Dissipative characteristics investigation of marble during reloading process considering pre-peak unloading damage |
| LI Jinglong1，ZHU Zihan1，2，YU Liyuan2，BAI Jiwen1，SUI Bin1，MENG Qingbin2，ZHANG Zhanqun2 |
(1. School of Civil Engineering，Shandong University，Jinan，Shandong 250061，China；2. State Key Laboratory for Geomechanics and Deep Underground Engineering，China University of Mining and Technology，Xuzhou，Jiangsu 221116，China)
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Abstract The strong excavation unloading under the high geo-stress conditions leads to damage or even failure of surrounding rock mass in deep underground engineering. As the main bearing structure of underground engineering，fracturing rock mass has significantly effect on engineering safety. It is necessary to study the energy dissipation characteristics of unloading damaged rock during reloading. Unloading damaged test was carried out by MTS815 test system. The unloading points were set as 70，80 and 90 MPa，and the unloading confining pressure rates were set as 0.1，0.5 and 1.0 MPa/s at each unloading point. Twenty-seven damaged specimens were obtained，on which uniaxial compress reloading test was performed. The unloading test results show that the dissipated energy density is positively correlated with the unloading point and negatively correlated with the unloading confining rate. The unloading point has greater influence on the dissipated energy density than unloading confining rate. The damage variable D increases with increasing the dissipative energy density. The uniaxial compress reloading test results show that the failure strain of specimens after unloading increases exponentially as D increases. The destruction and energy characteristics are divided into two stages with a threshold value of Dc = 0.10. When D＜Dc，the absorbed energy density，dissipated energy density and elastic energy density tend to be stable as the damage variable increases， and the failure mode of the unloading damaged sample is dominated by shear failure accompanied by a small amount of tensile cracks. When D> Dc，the proportion of the dissipated energy density increases sharply，while the elastic energy density and absorbed energy density decrease rapidly. The failure mode of the unloading damaged sample is mainly tensile failure. The fragment size is large and the quantity of fragments is small. This research is significant for the selection of mechanical parameters of surrounding rock and the optimization of support schemes in deep underground engineering.
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[1] 黄 达，谭 清，黄润秋. 高应力强卸荷条件下大理岩损伤破裂的应变能转化过程机制研究[J]. 岩石力学与工程学报，2012，31(12)：2 483–2 493.(HUANG Da，TAN Qing，HUANG Runqiu. Mechanism of strain energy conversion process for marble damage and fracture under high stress and rapid unloading[J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(12)：2 483–2 493.(in Chinese))
[2] 何满潮，谢和平，彭苏萍，等. 深部开采岩体力学研究[J]. 岩石力学与工程学报，2005，24(16)：2 803–2 813.(HE Manchao，XIE Heping，PENG Suping，et al. Study on rock mechanics in deep mining engineering[J]. Chinese Journal of Rock Mechanics and Engineering，2005，24(16)：2 803–2 813.(in Chinese))
[3] 钱七虎. 地下工程建设安全面临的挑战与对策[J]. 岩石力学与工程学报，2012，31(10)：1 945–1 956.(QIAN Qihu. Challenges faced by underground projects construction safety and countermeasures[J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(10)：1 945–1 956.(in Chinese))
[4] 朱维申，杨为民，项 吕，等. 大型洞室边墙松弛劈裂区的室内和现场研究及反馈分析[J]. 岩石力学与工程学报，2011，30(7)：1 310–1 317.(ZHU Weishen，YANG Weimin，XIANG Lv，et al. Laboratory and filed study of splitting failure on side wall of large-scale cavern and feedback analysis[J]. Chinese Journal of Rock Mechanics and Engineering，2011，30(7)：1 310–1 317.(in Chinese))
[5] 黄润秋，黄 达. 高地应力条件下卸荷速率对锦屏大理岩力学特性影响规律试验研究[J]. 岩石力学与工程学报，2010，29(1)：21–33.(HUANG Runqiu，HUANG Da. Experimental research on affection laws of unloading rates on mechanical properties of JINPING marble under high geostress[J]. Chinese Journal of Rock Mechanics and Engineering，2010，29(1)：21–33.(in Chinese))
[6] 黄润秋，黄 达，段绍辉，等. 锦屏Ⅰ级水电站地下厂房施工期围岩变形开裂特征及地质力学机制研究[J]. 岩石力学与工程学报，2011，30(1)：23–35.(HUANG Runqiu，HUANG Da，DUAN Shaohui，et al. Geomechanics mechanism and characteristics of surrounding rock mass deformation failure in construction phase for underground powerhouse of Jin-Ping I hydropower station[J]. Chinese Journal of Rock Mechanics and Engineering，2011，30(1)：23–35.(in Chinese))
[7] 吴世勇，王 鸽. 锦屏二级水电站深埋长隧洞群的建设和工程中的挑战性问题[J]. 岩石力学与工程学报，2010，29(11)：2 161–2 171. (WU Shiyong，WANG Ge. Challenge issues in construction and project of large-scale deep-buried tunnel group of Jin-Ping II hydropower station[J]. Chinese Journal of Rock Mechanics and Engineering，2010，29(11)：2 161–2 171.(in Chinese))
[8] LAU J S O，CHANDLER N A. Innovative laboratory testing[J]. International Journal of Rock Mechanics and Mining Sciences，2004，41(8)：1 427–1 445.
[9] HUANG D，LI Y. Conversion of strain energy in triaxial unloading tests on marble[J]. International Journal of Rock Mechanics and Mining Sciences，2014，66(1)：160–168.
[10] HUANG D，GUO Y Q，CEN D F ，et al. Experimental investigation on shear mechanical behavior of sandstone containing a pre-existing flaw under unloading normal stress with constant shear stress[J]. Rock Mechanics and Rock Engineering，2020.(to be Pressed). DOI：10.1007/s00603– 020–02136–w.
[11] ZHU T T，HUANG D. Experimental investigation of the shear mechanical behavior of sandstone under unloading normal stress[J]. International Journal of Rock Mechanics and Mining Sciences，2019，114：186–194.
[12] ZHU Z，HUANG D ，ZHANG Y F，et al. Experimental study on the effects of unloading normal stress on shear mechanical behaviour of sandstone containing a parallel fissure pair[J]. Rock Mechanics and Rock Engineering，2020，53(2)：1 647–1 663.
[13] DAI B，ZHAO G Y，KONIETZKY H，et al. Experimental and numerical study on the damage evolution behaviour of granitic rock during loading and unloading[J]. KSCE Journal of Civil Engineering，2018，22(9)：3 278–3 291.
[14] 哈秋舲. 岩石边坡工程与卸荷非线性岩石(体)力学[J]. 岩石力学与工程学报，1997，16(4)：386–391.(HA Qiuling. Rock slope engineering and unloading nonlinear rock mass mechanics[J]. Chinese Journal of Rock Mechanics and Engineering，1997，16(4)：386–391.(in Chinese))
[15] 吴 刚，孙 钧. 卸荷应力状态下裂隙岩体的变形和强度特性[J].岩石力学与工程学报，1998，17(6)：615–621.(WU Gang，SUN Jun. Deformation and strength characters of jointed rock mass under unloading stress states[J]. Chinese Journal of Rock Mechanics and Engineering，1998，17(6)：615–621.(in Chinese))
[16] 李建林，王乐华. 卸荷岩体的尺寸效应研究[J].岩石力学与工程学报，2003，22(12)：2 032–2 036.(LI Jianlin，WANG Lehua. Study on size effect of unloaded rock mass[J]. Chinese Journal of Rock Mechanics and Engineering，2003，22(12)：2 032–2 036.(in Chinese))
[17] 邱士利，冯夏庭，张传庆，等. 不同初始损伤和卸荷路径下深埋大理岩卸荷力学特性试验研究[J]. 岩石力学与工程学报，2012，31(8)：1 686–1 697.(QIU Shili，FENG Xiating，ZHANG Chuanqing，et al. Experimental research on mechanical properties of deep marble under different initial damage levels and unloading paths[J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(8)：1 686–1 697. (in Chinese))
[18] 张黎明，高 速，王在泉，等. 不同加卸荷应力路径下大理岩屈服函数研究[J]. 岩石力学与工程学报，2014，33(12)：2 497–2 503. (ZHANG Liming，GAO Su，WANG Zaiquan，et al. Analysis of yield functions of marble under different loading and unloading stress paths[J]. Chinese Journal of Rock Mechanics and Engineering，2014，33(12)：2 497–2 503.(in Chinese))
[19] 赵国彦，戴 兵，董陇军，等. 不同应力路径下岩石三轴卸荷力学特性与强度准则研究[J]. 岩土力学，2015，36(11)：3 121–3 127. (ZHAO Guoyan，DAI Bing，DONG Longjun，et al. Experimental research on mechanical characteristics and strength criterion of rock of triaxial unloading tests under different stress paths[J]. Rock and Soil Mechanics，2015，36(11)：3 121–3 127.(in Chinese))
[20] 刘 建，李建朋. 砂岩高应力峰前卸围压试验研究[J]. 岩石力学与工程学报，2011，30(3)：473–479.(LIU Jian，LI Jianpeng. Experimental research on sand stonepre-peak unloading process under high confining pressure[J]. Chinese Journal of Rock Mechanics and Engineering，2011，30(3)：473–479.(in Chinese))
[21] 谢和平，鞠 杨，黎立云，等. 岩体变形破坏过程的能量机制[J].岩石力学与工程学报，2008，27(9)：1 729–1 740.(XIE Heping，JU Yang，LI Liyun，et al. Energy mechanism of deformation and failure of rock masses[J]. Chinese Journal of Rock Mechanics and Engineering，2008，27(9)：1 729–1 740.(in Chinese))
[22] 黄 达，黄润秋，张永兴. 粗晶大理岩单轴压缩力学特性的静态加载速率效应及能量机制试验研究[J]. 岩石力学与工程学报，2012，31(2)：245–255.(HUANG Da，HUANG Runqiu，ZHANG Yongxing. Experimental investigations on static loading rate effects on mechanical properties and energy mechanism of coarse crystal grain marble under uniaxial compression[J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(2)：245–255.(in Chinese))
[23] 张志镇，高 峰. 单轴压缩下岩石能量演化的非线性特性研究[J].岩石力学与工程学报，2012，31(6)：1 198–1 207.(ZHANG Zhizhen，GAO Feng. Research on nonlinear characteristics of rock energy evolution under uniaxial compression[J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(6)：1 198–1 207.(in Chinese))
[24] 张 萍，杨春和，汪 虎，等. 页岩单轴压缩应力-应变特征及能量各向异性[J]. 岩土力学，2018，39(6)：2 106–2 114.(ZHANG Ping，YANG Chunhe，WANG Hu，et al. Stress-strain characteristics and anisotropy energy of shale under uniaxial compression[J]. Rock and Soil Mechanics，2018，39(6)：2 106–2 114.(in Chinese))
[25] 徐小丽，陈 琳，高 峰，等. 花岗岩的加载速率效应及能量机制研究[J]. 固体力学学报，2015，36(2)：154–163.(XU Xiaoli，CHEN Lin，GAO Feng，et al. Studies on loading rate effects and energy mechanism of granite[J]. Chinese Journal of Solid Mechanics，2015，36(2)：154–163.(in Chinese))
[26] 杨圣奇，徐卫亚，苏承东. 岩样单轴压缩变形破坏与能量特征研究[J]. 固体力学学报，2006，27(2)：213–216.(YANG Shenqi，XU Weiya，SU Chendong. Study on the deformation failure and energy properties of rock specimen in uniaxial compression[J]. Acta Mechanica Solida Sinica，2006，27(2)：213–216.(in Chinese))
[27] 梁昌玉，李 晓，王声星，等. 岩石单轴压缩应力–应变特征的率相关性及能量机制试验研究[J]. 岩石力学与工程学报，2012，31(9)：1 830–1 838.(LIANG Changyu，LI Xiao，WANG Shengxing，et al. Experimental investigations on rate-dependent stress-strain characteristics and energy mechanism of rock under uniaxial compression[J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(9)：1 830–1 838.(in Chinese))
[28] 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))
[29] 鞠 杨，谢和平. 基于应变等效性假说的损伤定义的适用条件[J].应用力学学报，1998，15(1)：43–49.(JU Yang，XIE Heping. A variable condition of the damage description based on hypothesis of strain equivalence[J]. Chinese Journal of Applied Mechanics，1998，15(1)：43–49.(in Chinese))
[30] MENG Q B，ZHANG M W，HAN L J，et al. Acoustic emission characteristics of red sandstone specimens under uniaxial cyclic loading and unloading compression[J]. Rock Mechanics and Rock Engineering，2018，51：969–988. |
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2020, Vol. 39 
