Mechanical Property Test at Different Unloading Velocities of Metamorphic Quartz Sandstone

Abstract

Abstract: Abstract： To study rock mechanical characteristics at different unloading velocities, taking the metamorphic quartz sandstone from Dabenliugou quarry special high slope in Jinping Hydropower Station as an example, unloading tests at different unloading velocities and confining pressures were conducted. Based on the tests, relationship curves between stress and strain were obtained, and affection laws of unloading velocity on stress and strain relationship, failure properties, failure stress difference, strength parameters were mainly studied. The results show that the brittle feature of unloading effect on rock failure is more obvious. The specimens under conventional loading test are compression shear failure, while the unloading specimens are tension shear failure. Elastic modulus is decreased with confining. As Vu becomes faster, the nonlinearity become more obvious, while the Poisson ratio is increased slowly. The rock cohesion is reduced but the inner friction angle is increased under unloading condition.

Key words: unloading velocity, triaxial unloading test, deformation characteristics, strength parameters

CLC Number:

TU 45

GUO Xifeng1,2，YIN Jianmin1，YAN Echuan2，ZHANG Lijie1,2. Mechanical Property Test at Different Unloading Velocities of Metamorphic Quartz Sandstone [J]. Journal of Shanghai Jiaotong University, 2016, 50(01): 78-83.

References

［1］李建林．卸荷岩体力学［M］.北京：中国水利水电出版社，2003. ［2］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. ［3］邱士利，冯夏庭，张传庆,等．不同卸围压速率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, 2010, 29(9)： 18071817. QIU Shili, FENG Xiating, ZHANG Chuanqing,et al. Experimental research on mechanical properties of deepburied marble under different unloading rates of confining pressures ［J］.Chinese Journal of Rock Mechanics and Engineering, 2010, 29(9), 18071817. ［4］王在泉，张黎明，孙辉, 等．不同卸荷速度下灰岩力学特性的试验研究［J］．岩土力学, 2011, 32(4)： 10451051. WANG Zaiquan, ZHANG Liming, SUN Hui, et al. Experimental study of mechanical properties of limestone under different unloading velocitier ［J］.Rock and Soil Mechanics, 2011, 32(4): 10451051. ［5］安泰龙，茅献彪，孙凤娟．卸荷速率对岩石强度影响的试验研究［J］．力学与实践, 2009, 31(6)：2124. AN Tailong, MAO Xianbiao, SUN Fengjuan. The effect of different unloading rates on rock strength［J］.Mechanics in Engineering, 2009, 31(6), 2124. ［6］刘国霖. 陡高边坡节理岩体卸荷岩体力学的物理基础［J］. 武汉水利电力大学（宜昌）学报, 2000，22（3）：185190. LIU Guolin.Physical base of unloading rock mass mechanics for jointed rock mass of highsteep rock slopes ［J］.Jourmal of University of Hydraulic and Electric Engineering/Yichang, 2000, 22(3), 185190. ［7］周维垣，杨若琼，剡公瑞,等. 岩体边坡非连续非线性卸荷及流变分析［J］. 岩石力学与工程学报, 1997，16（3）：210216. ZHOU Weiyuan，YANG Ruoqiong，YAN Gongrui, et al. Nonlinear and discontinuous deformation and rheological analysis for unloading rock slopes ［J］. Chinese Journal of Rock Mechanics and Engineering，1997，16（3）：210216. ［8］张永兴，哈秋舲. 三峡工程永久船闸陡高边坡岩体卸荷非线性力学分析［J］. 重庆建筑大学学报, 1997，19（2）：7279. ZHANG Yongxing，HA Qiuling. Nonlinear analysis of unloading rock mass related to the shiplock high slope of ThreeGorges Project ［J］. Journal of Chongqing Jianzhu University，1997，19（2）：7279. ［9］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）：20322036. LI Jianlin，WANG Lehua. Study on size effect of unloaded rock mass ［J］. Chinese Journal of Rock Mechanics and Engineering，2003，22（12）：20322036. ［10］李建林，王瑞红，蒋昱洲,等. 砂岩三轴卸荷力学特性试验研究［J］. 岩石力学与工程学报, 2010，29（10）：20342041. LI Jianlin，WANG Ruihong，JIANG Yuzhou，et al. Experimental study of sandstone mechanical properties by unloading triaxial tests［J］. Chinese Journal of Rock Mechanics and Engineering，2010，29（10）：20342041. ［11］董志宏，丁秀丽，李勤军,等．大奔流沟料场施工期高边坡稳定性数值模拟［J］．人民长江,2013, 44(14)： 1317. DONG Zhihong, DING Xiuli, LI Qinjun, et al. Numerical simulation of high slope stability of in construction period at dabenliugou quarry in construction period［J］.Yangtze River, 2013, 44(14): 1317. ［12］吴志虎．锦屏某高陡边坡在开挖卸荷下的岩体力学参数研究［D］．武汉：中国地质大学研究生院，2012. ［13］汪斌，朱杰兵，邬爱清，等. 锦屏大理岩加、卸载应力路径下力学性质试验研究［J］.岩石力学与工程学报，2008, 27(10)：21382145. WANG Bin, ZHU Jiebing, WU Aiqing, et al. Experimental study on mechanical properties of Jinping marble under loading and unloading stress paths［J］. Chinese Journal of Rock Mechanics and Engineering，2008，27(10)：21382145. ［14］汪斌，朱杰兵，邬爱清，等. 锦屏大理岩加、卸载应力路径下力学性质试验研究［J］.岩石力学与工程学报，2008, 27(10)：21382145. WANG Bin, ZHU Jiebing, WU Aiqing, et al. Experimental study on mechanical properties of Jinping marble under loading and unloading stress paths［J］. Chinese Journal of Rock Mechanics and Engineering，2008，27(10)：21382145. ［15］李宏哲，夏才初，闫子舰，等. 锦屏水电站大理岩在高应力条件下的卸荷力学特性研究［J］.岩石力学与工程学报，2007，26(10)：21042109． LI Hongzhe，XIA Caichu，YAN Zijian，et al．Study of the marble unloading properties of Jinping Hydropower Station under histress conditions［J］.Chinese Journal of Rock Mechanics and Engineering，2007，26(10)：21042109.