Abstract：In order to obtain surface fractal characteristics of fragments from rock mechanics test，especially the two-dimensional fractal characteristics at yardstick below sub-millimeter，Projective Covering Method was utilized. Firstly，unloading damage phenomenon at cave waist was simulated by rock burst test，and then marble samples damage characteristic was studied. Secondly，3D surface data of fragments from rock burst test was acquired by Confocal laser scanning microscope. Surface area at different yardstick was acquired by Triangulation method and two-dimensional characteristic of fragments was analyzed. Thirdly，lower limit of yardstick was confirmed in surface area calculation by Projective Covering Method. Three conclusions were drawn. Firstly，surface area of fragment had multi-fractal characteristic at yardstick from 0.625 μm to 639.375 μm. Secondly，the distribution of surface areas growth rate was similar with normal distribution. At yardstick below 0.625 μm，increase of surface area was little，so 0.625 μm could be regarded as lower limit of yardstick in surface area calculating by Projective Covering Method. Thirdly，fracture analysis from scanning electron microscopy confirmed the lower limit of yardstick in surface area calculating and the multi-fractal characteristic of fragments.
马艾阳，伍法权，沙 鹏，王定伟. 基于激光共聚焦扫描显微镜的岩爆试验碎片表面分形特征[J]. 岩石力学与工程学报, 2014, 33(S2): 3595-3600.
MA Aiyang，WU Faquan，SHA Peng，WANG Dingwei. FRACTAL CHARACTERISTIC OF FRAGMENT SURFACE FROM ROCK BURST TEST BASED ON CONFOCAL LASER SCANNING MICROSCOPE. , 2014, 33(S2): 3595-3600.
单晓云，李占金. 分形理论和岩石破碎的分形研究[J]. 河北理工学院学报，2003，25(2)：11-17.(SHAN Xiaoyun，LI Zhanjin. Fractal theory，characteristics and its application on rock fragmentation[J]. Journal of Hebei Institute of Technology，2003，25(2)：11-17.(in Chinese))
[2]
LANGE D A，JENNINGS H M，SHAN S P. Analysis of surface roughness using confocalmicroscopy[J]. Journal of Materials Science，1993，28：3879-3884.
[3]
谢和平，王金安. 岩石节理(断裂)表面的多重分形特征[J]. 力学学报，1998，30(5)：314-320.(XIE Heping，WANG Jin¢an. Multifractal behaviors of fracture surfaces in rocks[J]. Acta Mechanica Sinica，1998，30(5)：314-320.(in Chinese))
[4]
TOMÁŠ F，DALIBOR M，HAMLIN M J. Roughness of fracture surfaces and compressive strength of hydrated cement pastes[J]. Cement and Concrete Research，2010，40(6)：947-955.
[5]
HE MC，NIE W，ZHAO ZY，et al. Micro- and macro-fractures of coarse granite under true-triaxial unloading conditions[J]. Mining Science and Technology，2011，21(3)：389-394.
[6]
HE MC，NIE W，HAN LQ，et al. Microcrack analysis of Sanya grantite fragments from rockburst tests[J]. Mining Science and Technology，2010，20(2)：238-243.
[7]
何满潮，杨国兴，苗金丽，等. 岩爆实验碎屑分类及其研究方法[J]. 岩石力学与工程学报，2008，27(8)：1521-1529.(HE Manchao，YANG Guoxing，MIAO Jinli，et al. Classification and research methods of rockburst experimental fragments[J]. Chinese Journal of Rock Mechanics and Engineering，2008，27(8)：1521-1529.(in Chinese))
[8]
陈秀铜，李璐. 锦屏二级水电站引水隧洞区域三维初始地应力场反演回归分析[J]. 水文地质工程地质，2007，(6)：55-58.(CHEN Xiutong，LI Lu. Inverse analysis of initial field stress for JinpingIIhydropower station tunnel area[J]. Hydrogeology andEngineering Geology，2007，(6)：55-58.(in Chinese))
[9]
中国水电顾问集团华东勘测设计研究院. 锦屏二级水电站深埋引水隧洞工程地质条件和设计情况汇报——锦屏二级水电站深埋长隧洞安全快速施工关键技术国际咨询会[R]. 杭州：中国水电顾问集团华东勘测设计研究院，2009.(HydroChina Huadong Engineering Corporation. Report of conditions of engineering geology and design for deep diversion tunnel in Jinping II hydropower station—the international consultation on the safety of deep tunnels at Jinping II hydropower station[R]. Hangzhou：HydroChina Huadong Engineering Corporation，2009.(in Chinese))
高峰，谢和平. 几种断裂问题的分形描述中几个问题的商榷[J]. 高压物理学报，1996，10(2)：141-144.(GAO Feng，XIE Heping. A discussion on some problems in fractal descriptions of some fracture problems[J]. Chinese Journal of High Pressure Physics，1996，10(2)：141-144.(in Chinese))
[12]
谢和平. 分形-岩石力学导论[M]. 北京：科学出版社，1996：190-195.(XIE Heping. Fractals in rock mechanics[M]. Beijing：Science Press，1996：190-195.(in Chinese))
2014, Vol. 33 
