Abstract:The bedding fault zone in the dam site of Baihetan Hydropower Station is characterized by large scale, strong penetrability and complex geological conditions, which can control the underground caverns.Due to the large scale, the effects of wavelength fluctuation of the bedding fault zone cannot be considered accurately by normal field tests, and the size effect analysis needs to be introduced. A systematic study on the mechanical parameters of the bedding fault zone is carried out. Combining with the mechanical strength parameters obtained by the field tests, and the size effects of the bedding fault zone are analyzed by introducing the digital close-range photogrammetry technology and the particle flow numerical method. The mapping laws of the mechanical parameters of the bedding fault zone with joint roughness coefficient, soft filling thickness and size effects are revealed. In the engineering application, taking the advantages of the research results of bedding fault zone, the dome shape of tailrace surge chamber of Baihetan Hydropower Station is optimized. The method can provide a reference for other projects.
[1] GOODMAN R. The mechanical properties of joints[C]// Proc 3rd Int Congr International Society of Rock Mechanics, National Academy of Sciences, 1974, Washington D C: 127-140. [2] BANDIS S, LUMSDEN Ac, BARTON Nr.Fundamentals of rock joint deformation[J]. Int J Rock Mech Min Sci Geomech Abstr, 1983, 20(2): 249-268. [3] MIN K B, RUTQVIST J, TSANG C F, et al.Stress-dependent permeability of fracture rock masses: a numerical study[J]. Int J Rock Mech Min Sci, 2004, 41(10): 1191-1210. [4] HUDSON J A.Engineering Rock Mechanics[M]. London: Redwood Publishing Company, 1997. [5] STARK T D, EID H T.Drained residual strength of cohesive soils[J]. Journal of Geotechnical Engineering, ASCE, 1994, 120(5): 856-871. [6] 江权, 冯夏庭, 周辉, 等. 层间错动带的强度参数取值探讨[J]. 岩土力学, 2011, 32(11): 3379-3386. (JIANG Quan, FENG Xia-ting, ZHOU Hui, et al.Discussion of strength value for interlayer shearbelt[J]. Rock and Soil Mechanics, 2011, 32(11): 3379-3386. (in Chinese)) [7] 刘一伟, 张继春, 郭学彬, 等. 软弱夹层强度参数的室内模拟[J]. 西南科技大学学报, 2007(1): 30-34, 47. (LIU Yi-wei, ZHANG Ji-chun, GUO Xue-bing, et al.Study on laboratory simulation of the weak intercalation intensity parmeters[J]. Journal of Southwest University of Science and Technology, 2007(1): 30-34, 47. (in Chinese)) [8] 张咸恭, 聂德新, 韩文峰. 围压效应与软弱夹层泥化的可能性分析[J]. 地质评论, 1990, 30(2): 160-167. (ZHANG Xian-gong, NIE De-xin, HAN Wen-feng.The effect of confining pressure and the possibility of argillization of weak intercalations[J]. Discussion of Geology, 1990, 30(2): 160-167. (in Chinese)) [9] 符文熹, 聂德新, 尚岳全, 等. 地应力作用下软弱层带的工程特性研究[J]. 岩土工程学报, 2002, 24(5): 584-587. (FU Wen-xi, NIE De-xin, SHANG Yue-quan, et al.Study on engineering properties of weak layers underground stresses[J]. Chinese Journal of Geotechnical Engineering, 2002, 24(5): 584-587. (in Chinese)) [10] JIANG Y J, LI B, TANABASHI Y.Estimating the relation between surface roughnessand mechanical properties of rock joints[J]. International Journal of Rock Mechanics and Mining Sciences, 2006, 43(6): 837-846. [11] 刘宝琛, 张寄生, 杜奇中. 岩石抗压强度的尺寸效应[J]. 岩石力学与工程学报, 1998, 17(6): 611-614. (LIU Bao-chen, ZHANG Ji-sheng, DU Qi-zhong.A study of size effect for compression strength of rock[J]. Chinese Journal of Rock Mechanics and Engineering, 1998, 17(6): 611-614. (in Chinese)) [12] 杨圣奇, 苏承东, 徐卫亚. 岩石材料尺寸效应的试验和理论研究[J]. 工程力学, 2005(4): 112-118. (YANG Sheng-qi, SU Cheng-dong, XU Wei-ya.Experimental and theoretical study of size effect of rock material[J]. Engineering Mechanics, 2005(4): 112-118. (in Chinese)) [13] 张占荣, 盛谦, 杨艳霜, 等. 基于现场试验的岩体变形模量尺寸效应研究[J]. 岩土力学, 2010, 31(9): 2875-2881. (ZHANG Zhan-rong, SHENG Qian, YANG Yan-shuang, et al.Study of size effect of rock massdeformation modulus based on in-situ test[J]. Rock and Soil Mechanics, 2010, 31(9): 2875-2881.(in Chinese)) [14] BARTON N, CHOUBEY V.The shear strength of rock joints in theory and practice[J]. Rock Mechanics, 1977, 10(1/2): 1-54. [15] 梁正召, 张永彬, 唐世斌, 等. 岩体尺寸效应及其特征参数计算[J]. 岩石力学与工程学报, 2013, 32(6): 1157-1166. (LIANG Zheng-zhao, ZHANG Yong-bin, TANG Shi-bin, et al.Size effect of rock messes and associated representative element properties[J]. Chinese Journal of Rock Mechanics and Engineering, 2013, 32(6): 1157-1166. (in Chinese)) [16] 宋肖冰, 石安池, 郑伟锋, 等. 金沙江白鹤滩水电站坝区左岸边坡变形特征及机制分析[J]. 岩石力学与工程学报, 2012, 31(增刊2): 3533-3538. (SONG Xiao-bing, SHI An-chi, ZHENG Wei-feng, et al.Analysis of slope deformation characteristics and mechanism in leftbank of Baihetan hydropower station Jinsha River[J]. Chinese Journal of Rock Mechanics and Engineering, 2012, 31(S2): 3533-3538. (in Chinese)) [17] 张春生, 石安池, 吴关叶, 等. 金沙江白鹤滩水电站可行性研究报告专题18:缓倾角错动带工程地质研究报告[R]. 杭州: 中国电建集团华东勘测设计研究院有限公司, 2011. (ZHANG Chun-sheng, SHI An-chi, WU Guan-ye, et al.Feasibility Study Report of Baihetan Hydropower Station on Jinsha River 18: Engineering Geology Study Report of Low-Dip Bedding Fault Zone[R]. Hangzhou: Huadong Engineering Corporation Limited, 2011. (in Chinese)) [18] BARTON N, BANDIS S. Effects of block size on the shear behaviour of jointed rock[C]// Proceedings of the 23rd U.S. Symposium on Rock Mechanics, 1982, Berkeley: 739-760. [19] 土工试验方法标准:GB/T50123—1999[S]. 1999. (Standard for Soiltest Method: GB/T50123—1999[S]. 1999. (in Chinese)) [20] CUNDALL P A.Numerical experiments on rough joints in shear using a bonded particle model[C]// LEHNER F K,URAI J L ed. Aspects of Tectonic Faulting. Berlin: Springer, 1999: 1-9. [21] CHO N, MARTIN C D, SEGO D C.A clumped particle model for rock[J]. International Journal of Rock Mechanics and Mining Sciences, 2007, 44(7): 997-1010. [22] 余华中, 阮怀宁, 褚卫江. 岩石节理剪切力学行为的颗粒流数值模拟[J]. 岩石力学与工程学报, 2013, 32(7): 1482-1490. (YU Hua-zhong, RUAN Huai-ning, CHU Wei-jiang.Particle flow code modeling ofshear behavior of rock joints[J]. Chinese Journal of Rock Mechanics and Engineering, 2013, 32(7): 1482-1490. (in Chinese))