|
|
|
| TRIAXIAL UNLOADING TEST OF SANDSTONE AFTER HIGH TEMPERATURE |
| LI Jianlin1，CHEN Xing2，DANG Li1，DONG Yanhua3，CHENG Zhuang1，GUO Jing1 |
| (1. Key Laboratory of Geological Hazards in Three Gorges Reservoir Area，Ministry of Education，China Three Gorges University Yichang，Hubei 443002，China；2. Multipurpose Project Administration，China Three Gorges Corporation，Yichang，Hubei 443002，China；3. College of Hydraulic and Environmental Engineering，China Three Gorges University，Yichang，Hubei 443002，China) |
|
|
|
|
Abstract Comprehensively considering the relationship of the rebound value and longitudinal wave velocity with the temperature，the change laws of the longitudinal wave velocity and mechanical characteristic with temperature of the sandstone after high temperature are studied by triaxial unloading test. The test results show that：(1) The longitudinal wave velocity of the sandstone becomes lower with the increase of baking temperature. And the velocity decreases more rapidly while the temperature becomes higher. (2) With the increase of baking temperature，the rebound value of the sandstone is not a simple monotone increase/decrease. (3) The mechanical properties of sandstone change under the interaction of friction characteristics and cement properties. The friction characteristics strengthen greatly after high temperature baking；and then，the strength of sandstone increases greatly under the high confining pressure. (4) The longitudinal wave velocity，rebound value and strength don?t have inexorable law after high temperature baking. (5) The unloading damage of natural air-dried rock samples under low confining pressure still shows a significant compression and shear failure mode. (6) By analysis of the test results，we believe that the tensile strength of rock samples decreases significantly after high temperature baking. The interior of sandstone produces the thermal stress after heat treatment. The thermal stress induces the thermal cracking of the surface and internal microcracks，which is the essential reason of the tensile strength decreasing.
|
|
Received: 28 December 2010
|
|
|
|
| [1] 母润昌，高 平，刘若新，等. 华北地区韧性剪切带几种岩石的波速各向异性高温高压实验研究[J]. 地球物理学报，1995，38(2)：213–219.(MU Runchang，GAO Ping，LIU Ruoxin，et al. The experimental study of P-wave velocity anisotropy of mylonite and its surrounding rocks prom ductile shear zones of North China at elevated pressures and temperatures[J]. Chinese Journal of Geophysics，1995，38(2)：213–219.(in Chinese))
[2] 朱合华，闫治国，邓 涛，等. 3种岩石高温后的力学性质的试验研究[J]. 岩石力学与工程学报，2006，25(10)：1 945–1 950.(ZHU Hehua，YAN Zhiguo，DENG Tao，et al. Testing study on mechanical properties of tuff，granite and breccia after high temperatures[J]. Chinese Journal of Rock Mechanics and Engineering，2006，25(10)：1 945–1 950.(in Chinese))
[3] 何国梁，吴 刚，黄醒春，等. 砂岩高温前后超声特性的试验研究[J]. 岩土力学，2007，28(4)：779–784.(HE Guoliang，WU Gang，HUANG Xingchun，et al. Experimental study on ultrasonic properties of sandstone before and after high temperature[J]. Rock and Soil Mechanics，2007，28(4)：779–784.(in Chinese))
[4] 夏小和，陆雅萍，黄醒春，等. 高温后大理岩在不同应力水平下超声波特性的实验研究[J]. 上海交通大学学报，2004，38(7)：1 225–1 228. (XIA Xiaohe，LU Yaping，HUANG Xingchun，et al. Experimental research on ultrasonic characteristic of marble under the action of high temperature[J]. Journal of Shanghai Jiaotong University，2004，38(7)：1 225–1 228.(in Chinese))
[5] ODA M. Modern developments in rock structure characterization[C]// HUDSON J A ed. Comprehensive Rock Engineering. New York：Pergamon Press，1993：185–200.
[6] ALM O，JAKTLUND LL，KOU S Q. The influence of micro crack density on the elastic and fracture mechanical properties of stropa granite[J]. Physics of the Earth and Planetary Interiors，1985，40(3)：161–179.
[7] 寇绍全，ALM O. 微裂隙和花岗岩的抗拉强度[J]. 力学学报，1987，19(4)：366–373.(KOU Shaoquan，ALM O. Microcracks and the tensile strength of granite[J]. Acta Mechanica Sinica，1987，19(4)：366–373.(in Chinese))
[8] 王颖轶，张宏君，黄醒春，等. 高温作用下大理岩应力–应变全过程的试验研究[J]. 岩石力学与工程学报，2002，21(增2)：2 345– 2 349.(WANG Yingyi，ZHANG Hongjun，HUANG Xingchun，et al. Experimental study on whole stress-strain course of marble under the action of high temperature[J]. Chinese Journal of Rock Mechanics and Engineering，2002，21(Supp.2)：2 345–2 349.(in Chinese))
[9] 中华人民共和国行业规范编写组. SL264—2001 水电水利工程岩石试验规程[S]. 北京：中国水利水电出版社，2001.(The Professional Standards Compilation Group of People?s Republic of China. SL264—2001 Code for rock tests of hydroelectric and water conservancy Engineering[S]. Beijing：China Water Power Press，2001.(in Chinese))
[10] 康 健. 岩石热破裂的研究及应用[M]. 大连：大连理工大学出版社，2008：147–149.(KANG Jian. Research and application of thermal cracking of rock[M]. Dalian：Dalian University of Technology Press，2008：147–149.(in Chinese))
[11] 苏承东，郭文兵，李小双. 粗砂岩高温作用后力学效应的试验研究[J]. 岩石力学与工程学报，2008，27(6)：1 162–1 170.(SU Chengdong，GUO Wenbing，LI Xiaoshuang. Experimental research on mechanical properties of coarse sandstone after high temperatures[J]. Chinese Journal of Rock Mechanics and Engineering，2008，27(6)： 1 162–1 170.(in Chinese))
[12] 尤明庆，苏承东，周 英. 不同煤块的强度变形特性及强度准则的回归方法[J]. 岩石力学与工程学报，2003，22(12)：2 081–2 085. (YOU Mingqing，SU Chengdong，ZHOU Ying. Strength and deformation of specimen for different coal blocks and regression method of strength criterion[J]. Chinese Journal of Rock Mechanics and Engineering，2003，22(12)：2 081–2 085.(in Chinese))
[13] 尤明庆，苏承东，李小双. 损伤岩石岩样的力学特性与纵波速度关系研究[J]. 岩石力学与工程学报，2008，27(3)：458–467.(YOU Mingqing，SU Chengdong，LI Xiaoshuang. Study on relation between mechanical properties and longitudinal wave velocities for damaged rock samples[J]. Chinese Journal of Rock Mechanics and Engineering，2008，27(3)：458–467.(in Chinese))
[14] 张亚非. 建筑结构检测[M]. 1版. 武汉：武汉工业大学出版社，1995：21–25.(ZHANG Yafei. Detection of building structures[M]. 1st ed. Wuhan：Wuhan University of Technology Press，1995：21–25.(in Chinese))
[15] 张 渊，张 贤，赵阳升. 砂岩的热破裂过程[J]. 地球物理学报，2005，48(3)：656–659.(ZHANG Yuan，ZHANG Xian，ZHAO Yangsheng. Process of sandstone thermal cracking[J]. Chinese Journal of Geophysics，2005，48(3)：656–659.(in Chinese)) |
|
|
|
2011, Vol. 30 
