干燥及饱水岩石圆盘和圆环的巴西劈裂强度
|
摘要
为研究饱水对岩石抗拉强度的影响,对4种岩石的外径50 mm、厚30 mm左右的完整圆盘及不同内径(0～20 mm)的圆环进行巴西劈裂试验,对完整圆盘破裂块进行点载荷试验,对标准圆柱试样进行单轴压缩试验。基于完整圆盘劈裂强度的统计分析,除大理岩之外,其余岩石进行5次重复试验即可消除离散性。饱水对岩石拉伸强度的影响主要体现在黏结力降低,而对压缩强度的影响还包括内摩擦因数及孔隙压力。因而巴西劈裂强度的软化系数Rt大于压缩强度的软化系数Rc,而两者大致成线性关系表明圆盘的巴西劈裂与加载点的压应力集中相关;圆环内径增大到20 mm,干燥与饱水岩石圆环的巴西劈裂载荷大致相同,表明压应力的影响已经减小。圆环的巴西劈裂载荷随内径大致呈指数关系降低,而弹性力学的分析结果如Hobbs公式与实际情况差别较大。
To study the effect of saturation on the tensile strength of rock,dry and saturated rings of 30 mm in thickness,50 mm in external diameter,and 0-20 mm in internal diameter were conducted by Brazilian splitting test for four rocks.The broken discs after Brazilian splitting were point loaded.Dry and saturated cylindrical specimens were uniaxial compressed.Based on the statistical analysis of Brazilian splitting results of discs,the average strength of repeated test in 5 times may eliminate the dispersion from specimens except marble.The softening coefficient of Brazilian tensile strength is higher than and linear relative to that of uniaxial compressive strength.The influence of saturation on the Brazilian tensile strength mainly results from the high compressive stress in the neighbourhood of the load point and the cohesion decrease.Correspondingly,the splitting strengths are nearly the same for dry and saturated rings with 20 mm in internal diameter,which means that the compressive stress does not influence the ring splitting greatly.An exponential equation is proposed for rings to describe the relation between Brazilian splitting force and its inner diameter;and the Hobbs'equation based on the elastic mechanics has great difference from the experimental results.
To study the effect of saturation on the tensile strength of rock,dry and saturated rings of 30 mm in thickness,50 mm in external diameter,and 0-20 mm in internal diameter were conducted by Brazilian splitting test for four rocks.The broken discs after Brazilian splitting were point loaded.Dry and saturated cylindrical specimens were uniaxial compressed.Based on the statistical analysis of Brazilian splitting results of discs,the average strength of repeated test in 5 times may eliminate the dispersion from specimens except marble.The softening coefficient of Brazilian tensile strength is higher than and linear relative to that of uniaxial compressive strength.The influence of saturation on the Brazilian tensile strength mainly results from the high compressive stress in the neighbourhood of the load point and the cohesion decrease.Correspondingly,the splitting strengths are nearly the same for dry and saturated rings with 20 mm in internal diameter,which means that the compressive stress does not influence the ring splitting greatly.An exponential equation is proposed for rings to describe the relation between Brazilian splitting force and its inner diameter;and the Hobbs'equation based on the elastic mechanics has great difference from the experimental results.
引文
[1]BIENIAWSKI Z T,HAWKES I.Suggested methods for determining tensile strength of rock materials[J].International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts,1978,15(1):99-103.
[2]中华人民共和国行业标准编写组.SL264-2001水利水电工程岩石试验规程[S].北京:水利水电出版社,2001.(The Professional Standards Compilation Group of People's Republic of China.SL264-2001 Specifications for rock tests in water conservancy and hydroelectric engineering[S].Beijing:China Water Power Press,2001.(in Chinese))
[3]中华人民共和国国家标准编写组.GB/T 50266-99工程岩体试验方法标准[S].北京:中国计划出版社,1999.(The National Standards Compilation Group of People's Republic of China.GB/T 50266-99 Standards for test method of engineering rock masses[S].Beijing:China Planning Press,1999.(in Chinese))
[4]中华人民共和国行业标准编写组.DY-94岩石物理力学性质试验规程[S].北京:地质出版社,1995.(The Professional Standards Compilation Group of People's Republic of China.DY-94 Specifications for test method of physico-mechanical properties of rock[S].Beijing:Geological Publishing House,1995.(in Chinese))
[5]EFIMOV V P.The rock strength in different tension conditions[J].Journal of Mining Science,2009,45(6):569-575.
[6]CHAU K T,WEI X X.A three-dimensional analytic solution for the Brazilian test[C]//Frontiers of Rock Mechanics and Sustainable Development in the 21st Century(2001 ISRM and 2nd ARMS).Netherlands:A A Balkema,2001:141-144.
[7]SUNDARAM P N,CORRALES J M.Brazilian tensile strength of rocks with different elastic properties in tension and compression[J].International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts,1980,17(2):131-133.
[8]喻勇.质疑岩石巴西圆盘拉伸强度试验[J].岩石力学与工程学报,2005,24(7):1 150-1 157.(YU Yong.Questioning the validity of the Brazilian test for determining tensile strength of rocks[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(7):1 150-1 157.(in Chinese))
[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):3 106-3 112.(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):3 106-3 112.(in Chinese))
[10]HOBBS D W.An assessment of a technique for determining the tensile strength of rock[J].British Journal of Applied Physics,1965,16(2):259-268.
[11]HUDSON J A,BROWN E T,RUMMEL F.The controlled failure of rock discs and rings loaded in diametral compression[J].International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts,1972,9(2):241-248.
[12]CHEN C S,HSU S C.Measurement of indirect tensile strength of anisotropic rocks by the ring test[J].Rock Mechanics and Rock Engineering,2001,34(4):293-321.
[13]朱万成,冯丹,周锦添,等.圆环试样用于岩石间接拉伸强度测试的数值试验[J].东北大学学报(自然科学版),2004,25(9):899-902.(ZHU Wancheng,FENG Dan,CHAU Kamtim,et al.Numerical test using ring specimen as medium to determine indirect tensile strength of rock[J].Journal of Northeast University(Natural Science),2004,25(9):899-902.(in Chinese))
[14]张盛,何江达,王启智.用圆孔平台巴西圆盘确定岩石拉伸强度的非局部应力方法[J].应用力学学报,2008,25(3):503-507.(ZHANG Sheng,HE Jiangda,WANG Qizhi.Nonlocal stress method for determination of rock tensile strength holed-flattened Brazilian disc specimen[J].Chinese Journal of Applied Mechanics,2008,25(3):503-507.(in Chinese))
[15]尤明庆,苏承东.砂岩孔道试样压拉应力下强度和破坏的研究[J].岩石力学与工程学报,2010,29(6):1 096-1 105.(YOU Mingqing,SU Chengdong.Study on strength and failure of hollow cylinders and rings of sandstone under compression-tension stresses[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(6):1 096-1 105.(in Chinese))
[16]TOKOVVY Y V,HUNG K M,MA C C.Determination of stresses and displacements in a thin annular disk subjected to diametral compression[J].Journal of Mathematical Sciences,2010,165(3):342-354.
[17]颜玉定,廖远群,吴景浓,等.围压条件下岩石的抗拉强度[J].华南地震,1991,11(2):1-12.(YAN Yuding,LIAO Yuanqun,WU Jingnong,et al.Tension resistant strength of rock under confining pressure[J].South China Journal of Seismology,1991,11(2):1-12.(in Chinese))
[18]RAMSEY J M,CHESTER M F.Hybrid fracture and the transition from extension fracture to shear fracture[J].Nature,2004,428:63-66.
[19]尤明庆,周少统,苏承东.岩石试样在围压下直接拉伸试验[J].河南理工大学学报,2006,25(4):255-261.(YOU Mingqing,ZHOU Shaotong,SU Chengdong.Direct tensile experiment of rock specimens under confining pressure[J].Journal of Henan Polytechnic University,2006,25(4):255-261.(in Chinese))
[20]山口梅太郎.花こぅ岩の强度试验にぉける试验片の数につぃて[J].材料,1966,160(16):520-528.
[21]OKUBO F,FUKUI K.Complete stress-strain curves for various rock types in uniaxial tension[J].International Journal of Rock Mechanics and Mining Sciences,1996,33(6):549-556.
[22]JAEGER J C,HOSKINS E R.Rock failure under the confined Brazilian test[J].Journal of Geophysics Research,1966,71(10):2 651-2 659.
[23]JAEGER J C.Failure of rocks under tensile conditions[J].International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts,1967,4(2):219-227.
[24]HARDY H R,JAYARAMAN N I.An investigation of methods for the determination of the tensile strength of rock[C]//Proceedings of the 2nd Congress of International Society for Rock Mechanics.[S.l].:[s.n].,1970:85-92.
[25]COVIELLO A,LAGIOIA R,NOVA R.On the measurement of the tensile strength of soft rocks[J].Rock Mechanics and Rock Engineering,2005,38(4):251-275.
[26]TRAPEZDNIKOV L P.Temperature crack resistance in massive concrete[M].Moscow:Energoatomizdat,1986.
[27]YOU M.Three independent parameters needed to describe conventional triaxial compression strength of intact rocks[J].Journal of Rock Mechanics and Geotechnical Engineering,2010,2(4):350-
[2]中华人民共和国行业标准编写组.SL264-2001水利水电工程岩石试验规程[S].北京:水利水电出版社,2001.(The Professional Standards Compilation Group of People's Republic of China.SL264-2001 Specifications for rock tests in water conservancy and hydroelectric engineering[S].Beijing:China Water Power Press,2001.(in Chinese))
[3]中华人民共和国国家标准编写组.GB/T 50266-99工程岩体试验方法标准[S].北京:中国计划出版社,1999.(The National Standards Compilation Group of People's Republic of China.GB/T 50266-99 Standards for test method of engineering rock masses[S].Beijing:China Planning Press,1999.(in Chinese))
[4]中华人民共和国行业标准编写组.DY-94岩石物理力学性质试验规程[S].北京:地质出版社,1995.(The Professional Standards Compilation Group of People's Republic of China.DY-94 Specifications for test method of physico-mechanical properties of rock[S].Beijing:Geological Publishing House,1995.(in Chinese))
[5]EFIMOV V P.The rock strength in different tension conditions[J].Journal of Mining Science,2009,45(6):569-575.
[6]CHAU K T,WEI X X.A three-dimensional analytic solution for the Brazilian test[C]//Frontiers of Rock Mechanics and Sustainable Development in the 21st Century(2001 ISRM and 2nd ARMS).Netherlands:A A Balkema,2001:141-144.
[7]SUNDARAM P N,CORRALES J M.Brazilian tensile strength of rocks with different elastic properties in tension and compression[J].International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts,1980,17(2):131-133.
[8]喻勇.质疑岩石巴西圆盘拉伸强度试验[J].岩石力学与工程学报,2005,24(7):1 150-1 157.(YU Yong.Questioning the validity of the Brazilian test for determining tensile strength of rocks[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(7):1 150-1 157.(in Chinese))
[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):3 106-3 112.(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):3 106-3 112.(in Chinese))
[10]HOBBS D W.An assessment of a technique for determining the tensile strength of rock[J].British Journal of Applied Physics,1965,16(2):259-268.
[11]HUDSON J A,BROWN E T,RUMMEL F.The controlled failure of rock discs and rings loaded in diametral compression[J].International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts,1972,9(2):241-248.
[12]CHEN C S,HSU S C.Measurement of indirect tensile strength of anisotropic rocks by the ring test[J].Rock Mechanics and Rock Engineering,2001,34(4):293-321.
[13]朱万成,冯丹,周锦添,等.圆环试样用于岩石间接拉伸强度测试的数值试验[J].东北大学学报(自然科学版),2004,25(9):899-902.(ZHU Wancheng,FENG Dan,CHAU Kamtim,et al.Numerical test using ring specimen as medium to determine indirect tensile strength of rock[J].Journal of Northeast University(Natural Science),2004,25(9):899-902.(in Chinese))
[14]张盛,何江达,王启智.用圆孔平台巴西圆盘确定岩石拉伸强度的非局部应力方法[J].应用力学学报,2008,25(3):503-507.(ZHANG Sheng,HE Jiangda,WANG Qizhi.Nonlocal stress method for determination of rock tensile strength holed-flattened Brazilian disc specimen[J].Chinese Journal of Applied Mechanics,2008,25(3):503-507.(in Chinese))
[15]尤明庆,苏承东.砂岩孔道试样压拉应力下强度和破坏的研究[J].岩石力学与工程学报,2010,29(6):1 096-1 105.(YOU Mingqing,SU Chengdong.Study on strength and failure of hollow cylinders and rings of sandstone under compression-tension stresses[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(6):1 096-1 105.(in Chinese))
[16]TOKOVVY Y V,HUNG K M,MA C C.Determination of stresses and displacements in a thin annular disk subjected to diametral compression[J].Journal of Mathematical Sciences,2010,165(3):342-354.
[17]颜玉定,廖远群,吴景浓,等.围压条件下岩石的抗拉强度[J].华南地震,1991,11(2):1-12.(YAN Yuding,LIAO Yuanqun,WU Jingnong,et al.Tension resistant strength of rock under confining pressure[J].South China Journal of Seismology,1991,11(2):1-12.(in Chinese))
[18]RAMSEY J M,CHESTER M F.Hybrid fracture and the transition from extension fracture to shear fracture[J].Nature,2004,428:63-66.
[19]尤明庆,周少统,苏承东.岩石试样在围压下直接拉伸试验[J].河南理工大学学报,2006,25(4):255-261.(YOU Mingqing,ZHOU Shaotong,SU Chengdong.Direct tensile experiment of rock specimens under confining pressure[J].Journal of Henan Polytechnic University,2006,25(4):255-261.(in Chinese))
[20]山口梅太郎.花こぅ岩の强度试验にぉける试验片の数につぃて[J].材料,1966,160(16):520-528.
[21]OKUBO F,FUKUI K.Complete stress-strain curves for various rock types in uniaxial tension[J].International Journal of Rock Mechanics and Mining Sciences,1996,33(6):549-556.
[22]JAEGER J C,HOSKINS E R.Rock failure under the confined Brazilian test[J].Journal of Geophysics Research,1966,71(10):2 651-2 659.
[23]JAEGER J C.Failure of rocks under tensile conditions[J].International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts,1967,4(2):219-227.
[24]HARDY H R,JAYARAMAN N I.An investigation of methods for the determination of the tensile strength of rock[C]//Proceedings of the 2nd Congress of International Society for Rock Mechanics.[S.l].:[s.n].,1970:85-92.
[25]COVIELLO A,LAGIOIA R,NOVA R.On the measurement of the tensile strength of soft rocks[J].Rock Mechanics and Rock Engineering,2005,38(4):251-275.
[26]TRAPEZDNIKOV L P.Temperature crack resistance in massive concrete[M].Moscow:Energoatomizdat,1986.
[27]YOU M.Three independent parameters needed to describe conventional triaxial compression strength of intact rocks[J].Journal of Rock Mechanics and Geotechnical Engineering,2010,2(4):350-
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心