提出一种基于弹性力学平面问题傅里叶级数的长方形岩石劈裂应力解析方法。为了与该傅里叶级数解析方法比较,建立了相同劈裂载荷条件下长方形岩石三维有限元模型,分析了劈裂试件的应力分布,以及试件宽长比、垫条宽度对劈裂试件应力分布的影响。结果表明,两种方法的分析结果一致,劈裂试件的最大拉应力未出现在试件中心,而是出现在试件x=0 对称轴上靠近边界的某一点;最大拉应力随着垫条宽度2c 和试件宽长比b/a 的增加而减小;正方形试件的最大拉应力大于圆柱形试件的最大拉应力。通过类岩石材料劈裂实验,证明了该傅里叶级数解析方法描述的长方形岩石劈裂应力分布规律与实验结果相符。
The stress distribution of rectangular rock under split loads is an important research topic of rock mechanics. The formula of rectangular specimen tensile stress under splitting loads can be deduced by the Fourier series solution of the elastic plane problem. To compare the theoretical solution and the finite element solution, a dimensional finite element model of the rectangular specimen is built under the same loading conditions. The stress distribution and the impact of the width of spacer and the width to length ratio are analyzed. It is shown that results of the theoretical solution and the finite element solution are consistent. The maximum tensile stress does not appear in the center of the specimen but in a certain point with coordinates. The maximum tensile stress decreases with the increasing of the width of spacer and the width to length ratio b/a. The tensile stress distribution patterns of cylindrical specimen and square specimen are consistent, but the tensile stress of the square specimen is greater than that of the cylindrical specimen. It is proved that the splitting stress distribution of rectangular rock obtained by the Fourier series analysis method is consistent with the rock-like material splitting experimental results.
[1] 王启智, 贾学明. 用平台巴西圆盘试样确定脆性岩石的弹性模量、拉 伸强度和断裂韧度:第一部分解析和数值结果[J]. 岩石力学与工程 学报, 2002, 21(9): 1285-1289. Wang Qizhi,Jia Xueming. Determination of elastic modulus, tensile strength and fracture toughness of brittle rocks by using flattened Brazilian disk specimen. Part I: Analytical and numerical results[J]. Chinese Journal of Rock Mechanics and Engineering, 2002, 21(9): 1285-1289.
[2] 王启智, 吴礼舟. 用平台巴西圆盘试样确定脆性岩石的弹性模量、拉伸强度和断裂韧度:第二部分试验结果[J]. 岩石力学与工程学报, 2004, 23(2): 199-204. Wang Qizhi, Wu Lizhou. Determination of elastic modulus, tensile strength and fracture toughness of brittle rocks by using flattened Brazilian disk specimen. Part II: Experimental results[J]. Chinese Journal of Rock Mechanics and Engineering, 2004, 23(2):199-204.
[3] 于庆磊, 唐春安, 杨天鸿. 平台中心角对岩石抗拉强度测定影响的数 值分析[J]. 岩土力学, 2008, 29(12): 3251-3260. Yu Qinglei, Tang Chunan, Yang Tianhong. Numerical analysis of influence of central angle of flats on tensile strength of granite in split test with flattened disk[J]. Rock and Soil Mechanics, 2008, 29(12): 3251-3260.
[4] 沈明荣. 岩体力学[M]. 上海: 同济大学出版社, 1999. Shen Mingrong. Rock mass mechanics[M]. Shanghai: Tongji University Press, 1999.
[5] 张少华, 缪协兴, 赵海云. 试验方法对岩石抗拉强度测定方法的影响[J]. 中国矿业大学学报, 1999, 28(3): 243-246. Zhang Shaohua, Miao Xiexing, Zhao Haiyun. Influence of test methods on measured results of rock tensile strength[J]. Journal of China University of Mining & Technology, 1999, 28(3): 243-246.
[6] 吴基文, 闫立宏. 煤岩抗拉强度两种室内间接测定方法比较与成果分 析[J]. 岩石力学与工程学报, 2004, 23(10): 1643-1647. Wu Jiwen,Yan Lihong. Comparison study on two kinds of indirect measurement methods of tensile strength of coal[J]. Chinese Journal of Rock Mechanics and Engineering, 2004, 23(10): 1643-1647.
[7] Hondros G. The evaluation of Poisson's ratio and the modulus of materials of a low tensile resistance by the Brazilian (indirect tensile)[J]. Australian Journal of Applied Science, 1959, 10(3): 243-268.
[8] Mellor M, Hawkes I. Measurement of tensile strength by diameter compression[J]. Engineering Geology, 1971, 5(2): 173-225.
[9] 尤明庆, 苏承东. 平台巴西圆盘劈裂和岩石抗拉强度的试验研究[J].岩石力学与工程学报, 2004, 23(18): 3107-3112. You Mingqing,Su Chengdong. Experimental study on split test with flattened disk and tensile strength of rock[J]. Chinese Journal of Rock Mechanics and Engineering, 2004, 23(18): 3107-3112.
[10] 喻勇, 徐跃良. 采用平台巴西圆盘试样测试岩石抗拉强度的方法[J]. 岩石力学与工程学报, 2006, 25(7): 1457-1462. Yu Yong, Xu Yueliang. Method to determine tensile strength of rock using flattened brazilian disk[J]. Chinese Journal of Rock Mechanics and Engineering, 2006, 25(7): 1457-1462.
[11] Bieniawski Z T, Hawkes I. Suggested methods for determining tensile strength of rock materials[J]. International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1978, 15(1): 99-103.
[12] Arikan F, Ulusay R, Aydin N. Characterization of weathered acidic volcanic rocks and a weathering classification based on a rating system[J]. Bulletin of Engineering Geology and the Environment, 2007, 66(4): 415-430.
[13] Borrelli L, Greco R, Gulla G. Weathering grade of rock masses as a predisposing factor to slope instabilities: Reconnaissance and control procedures[J]. Geomorphology, 2007, 87(3): 158-175.
[14] Gupta V, Sharma R, Sah M P. Surface weathering of gneiss, northwestern higher Himalaya, India[J]. Quarterly Journal of Engineering Geology and Hydrogeology, 2011, 44(1): 135-140.
[15] Zorlu K. Description of the weathering states of building stones by fractal geometry and fuzzy inference system in the Olba ancient city (Southern Turkey)[J]. Engineering Geology, 2008, 101(3-4): 124-133.
[16] 刘勇军, 朱岳明, 曹为民, 等. 长方体劈裂试验的可行性研究[J]. 河海 大学学报, 2001, 29(5): 100-102. Liu Yongjun, Zhu Yueming, Cao Weiming, et al. The feasibility study on cuboid split test[J]. Journal of Hohai University, 2001, 29(5): 100-102.