渗流作用下柱状节理岩体强度特性试验
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摘要
为研究白鹤滩水电站柱状节理玄武岩在高渗透压力作用下的强度特性,采用与水电站现场岩体物理力学性质相近的人工材料,制作具有相同节理构造的柱状节理岩体模型试样,开展了不同渗透压力的渗流应力耦合三轴力学试验,分析了渗透压力对柱状节理岩体的破坏模式、强度和渗流量的影响。试验结果表明:渗流作用下柱状节理岩体的破坏模式为沿着节理倾角的滑移破坏;渗流作用下的柱状节理岩体具有较低的强度,三轴压缩峰值强度与渗透压力呈负相关关系;应力应变曲线可分为4个阶段,渗流量随应力应变曲线呈现出阶段性特征,渗透压力对岩体强度和渗流量影响较明显。
Columnar jointed basalt develops in the arch dam foundation and the dam abutment of Baihetan Hydropower Station. After the water storage in the hydropower station,the head difference between the upstream and the downstream of dam will form a high seepage pressure,and the strength characteristics of rock mass under high osmotic pressure is one of concerned scientific issues in rock engineering. Therefore,artificial material with physical and mechanical characteristics similar to those of in-situ rock mass was used to make the columnar jointed rock mass model samples with the same joint structure. In order to investigate the effect of seepage flow pressure on the failure modes,strength and seepage quantity of jointed rock mass,a series of triaxial tests on the columnar jointed rock mass samples were carried out under different osmotic pressures. The experimental results indicate that the failure mode of columnar jointed rock mass is sliding failure which alongs the joint dip angle under seepage flow pressure. Moreover,the columnar jointed rock mass has a lower strength under seepage,and the peak strength of triaxial compression test is negatively correlated with the osmotic pressure. Furthermore,four stages for the stressstrain curve of columnar jointed rock mass under triaxial compression condition are summarized based on test results,and seepage quantity shows phased characteristics with the stress-strain curve. Additionally,the effect of seepage on columnar jointed rock mass strength and seepage flow is obvious.
Columnar jointed basalt develops in the arch dam foundation and the dam abutment of Baihetan Hydropower Station. After the water storage in the hydropower station,the head difference between the upstream and the downstream of dam will form a high seepage pressure,and the strength characteristics of rock mass under high osmotic pressure is one of concerned scientific issues in rock engineering. Therefore,artificial material with physical and mechanical characteristics similar to those of in-situ rock mass was used to make the columnar jointed rock mass model samples with the same joint structure. In order to investigate the effect of seepage flow pressure on the failure modes,strength and seepage quantity of jointed rock mass,a series of triaxial tests on the columnar jointed rock mass samples were carried out under different osmotic pressures. The experimental results indicate that the failure mode of columnar jointed rock mass is sliding failure which alongs the joint dip angle under seepage flow pressure. Moreover,the columnar jointed rock mass has a lower strength under seepage,and the peak strength of triaxial compression test is negatively correlated with the osmotic pressure. Furthermore,four stages for the stressstrain curve of columnar jointed rock mass under triaxial compression condition are summarized based on test results,and seepage quantity shows phased characteristics with the stress-strain curve. Additionally,the effect of seepage on columnar jointed rock mass strength and seepage flow is obvious.
引文
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[3]江权,冯夏庭,樊义林,等.柱状节理玄武岩各向异性特性的调查与试验研究[J].岩石力学与工程学报,2013,32(12):2527-2535.(JIANG Quan,FENG Xiating,FAN Yilin,et al.Survey and laboratory study of anisotropic properties for columnar jointed basaltic rock mass[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(12):2527-2535.(in Chinese))
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[5]LONDE P.The Malpasset Dam failure[J].Engineering Geology,1987,24(1):331-338.
[6]BRADY B,CRAMER M L,HART R D.Preliminary analysis of a loading test on a large basalt block[J].International Journal of Rock Mechanics&Mining Science&Geomechanics Abstracts,1985,22(5):345-348.
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[8]郑文堂,徐卫亚,邬爱清,等.柱状节理开挖模拟洞数值原位试验[J].岩土力学,2007,28(增刊1):253-257.(ZHENGWentang,XU Weiya,WU Aiqing,et al.Numerical in situ testing of excavation experimental cavity on columnar joints[J].Rock and Soil Mechanics,2007,28(Sup1):253-257.(in Chinese))
[9]JIANG Q,FENG X T,HATZOR Y H,et al.Mechanical anisotropy of columnar jointed basalts:an example from the Baihetan hydropower station,China[J].Engineering Geology,2014,175(3):35-45.
[10]HAO X J,FENG X T,YANG C X,et al.Analysis of EDZ development of columnar jointed rock mass in the Baihetan Diversion Tunnel[J].Rock Mechanics&Rock Engineering,2015,49:1-24.
[11]郝宪杰,冯夏庭,江权,等.基于电镜扫描实验的柱状节理隧洞卸荷破坏机制研究[J].岩石力学与工程学报,2013,32(8):1647-1655.(HAO Xianjie,FENG Xiating,JIANG Quan,et al.Research on unloading failure mechanism of columnar jointed rock mass in tunnel based on scanning electron microscopy experiments[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(8):1647-1655.(in Chinese))
[12]肖维民,邓荣贵,付小敏,等.模拟柱状节理岩体常规三轴压缩下变形和强度特性试验研究[J].岩石力学与工程学报,2015,34(增刊1):2817-2826.(XIAO Weimin,DENG Ronggui,FU Xiaomin,et al.Experimental study of deformation and strength properties of simulated columnar jointed rock masses under conventional triaxial compression[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(Sup1):2817-2826.(in Chinese))
[13]肖维民,邓荣贵,付小敏,等.单轴压缩条件下柱状节理岩体变形和强度各向异性模型试验研究[J].岩石力学与工程学报,2015,34(5):957-963.(XIAO Weimin,DENG Ronggui,FU Xiaomin,et al.Model experiments on deformation and strength anisotropy of columnar jointed rock masses under uniaxial compression[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(5):957-963.(in Chinese))
[14]JI H,ZHANG J C,XU W Y,et al.Experimental investigation of the anisotropic mechanical properties of a columnar jointed rock mass:observations from laboratory-based physical modelling[J].Rock Mechanics&Rock Engineering,2017,50(4):1-13.
[15]LIN Zhinan,XU Weiya,WANG Huanling,et al.Anisotropic characteristic of irregular columnar-jointed rock mass based on physical model test[J].KSCE Journal of Civil Engineering,2017,21(5):1728-1734.
[16]巢志明,王环玲,徐卫亚,等.循环加卸载下柱状节理材料渗透率和孔隙度演化规律研究[J].岩石力学与工程学报,2017,36(1):124-141.(CHAO Zhiming,WANG Huanling,XU Weiya,et al.Permeability and porosity of columnar jointed rock under cyclic loading and unloading[J].Chinese Journal of Rock Mechanics and Engineering,2017,36(1):124-141.(in Chinese))
[17]周维垣,杨若琼,刘耀儒,等.高拱坝整体稳定地质力学模型试验研究[J].水力发电学报,2005,24(1):53-58,64.(ZHOUWeiyuan,YANG Ruoqiong,LIU Yaoru,et al.Research on geomechanical model of rupture tests of arch dams for their stability[J].Journal of Hydroelectric Engineering,2005,24(1):53-58,64.(in Chinese))
[2]徐松年.试论玄武岩柱状节理的形态分类与成因分类[J].浙江大学学报(理学版),1982,9(4):126-137.(XU Songnian.Discussion on morphological and gentical classification of columnar joints in basalt[J].Journal of Zhejiang University(Science Edition),1982,9(4):126-137.(in Chinese))
[3]江权,冯夏庭,樊义林,等.柱状节理玄武岩各向异性特性的调查与试验研究[J].岩石力学与工程学报,2013,32(12):2527-2535.(JIANG Quan,FENG Xiating,FAN Yilin,et al.Survey and laboratory study of anisotropic properties for columnar jointed basaltic rock mass[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(12):2527-2535.(in Chinese))
[4]徐卫亚,郑文棠,石安池.水利工程中的柱状节理岩体分类及质量评价[J].水利学报,2011,42(3):262-270.(XUWeiya,ZHENG Wentang,SHI Anchi.Classification and quality assessment of irregular columnar jointed basaltic rock mass for hydraulic engineering[J].Journal of Hydraulic Engineering,2011,42(3):262-270.(in Chinese))
[5]LONDE P.The Malpasset Dam failure[J].Engineering Geology,1987,24(1):331-338.
[6]BRADY B,CRAMER M L,HART R D.Preliminary analysis of a loading test on a large basalt block[J].International Journal of Rock Mechanics&Mining Science&Geomechanics Abstracts,1985,22(5):345-348.
[7]孟国涛.柱状节理岩体各向异性力学分析及其构成应用[D].南京:河海大学,2007.
[8]郑文堂,徐卫亚,邬爱清,等.柱状节理开挖模拟洞数值原位试验[J].岩土力学,2007,28(增刊1):253-257.(ZHENGWentang,XU Weiya,WU Aiqing,et al.Numerical in situ testing of excavation experimental cavity on columnar joints[J].Rock and Soil Mechanics,2007,28(Sup1):253-257.(in Chinese))
[9]JIANG Q,FENG X T,HATZOR Y H,et al.Mechanical anisotropy of columnar jointed basalts:an example from the Baihetan hydropower station,China[J].Engineering Geology,2014,175(3):35-45.
[10]HAO X J,FENG X T,YANG C X,et al.Analysis of EDZ development of columnar jointed rock mass in the Baihetan Diversion Tunnel[J].Rock Mechanics&Rock Engineering,2015,49:1-24.
[11]郝宪杰,冯夏庭,江权,等.基于电镜扫描实验的柱状节理隧洞卸荷破坏机制研究[J].岩石力学与工程学报,2013,32(8):1647-1655.(HAO Xianjie,FENG Xiating,JIANG Quan,et al.Research on unloading failure mechanism of columnar jointed rock mass in tunnel based on scanning electron microscopy experiments[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(8):1647-1655.(in Chinese))
[12]肖维民,邓荣贵,付小敏,等.模拟柱状节理岩体常规三轴压缩下变形和强度特性试验研究[J].岩石力学与工程学报,2015,34(增刊1):2817-2826.(XIAO Weimin,DENG Ronggui,FU Xiaomin,et al.Experimental study of deformation and strength properties of simulated columnar jointed rock masses under conventional triaxial compression[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(Sup1):2817-2826.(in Chinese))
[13]肖维民,邓荣贵,付小敏,等.单轴压缩条件下柱状节理岩体变形和强度各向异性模型试验研究[J].岩石力学与工程学报,2015,34(5):957-963.(XIAO Weimin,DENG Ronggui,FU Xiaomin,et al.Model experiments on deformation and strength anisotropy of columnar jointed rock masses under uniaxial compression[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(5):957-963.(in Chinese))
[14]JI H,ZHANG J C,XU W Y,et al.Experimental investigation of the anisotropic mechanical properties of a columnar jointed rock mass:observations from laboratory-based physical modelling[J].Rock Mechanics&Rock Engineering,2017,50(4):1-13.
[15]LIN Zhinan,XU Weiya,WANG Huanling,et al.Anisotropic characteristic of irregular columnar-jointed rock mass based on physical model test[J].KSCE Journal of Civil Engineering,2017,21(5):1728-1734.
[16]巢志明,王环玲,徐卫亚,等.循环加卸载下柱状节理材料渗透率和孔隙度演化规律研究[J].岩石力学与工程学报,2017,36(1):124-141.(CHAO Zhiming,WANG Huanling,XU Weiya,et al.Permeability and porosity of columnar jointed rock under cyclic loading and unloading[J].Chinese Journal of Rock Mechanics and Engineering,2017,36(1):124-141.(in Chinese))
[17]周维垣,杨若琼,刘耀儒,等.高拱坝整体稳定地质力学模型试验研究[J].水力发电学报,2005,24(1):53-58,64.(ZHOUWeiyuan,YANG Ruoqiong,LIU Yaoru,et al.Research on geomechanical model of rupture tests of arch dams for their stability[J].Journal of Hydroelectric Engineering,2005,24(1):53-58,64.(in Chinese))