二叠系炭质页岩软弱夹层剪切蠕变特性研究
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摘要
以西南灰岩山区二叠系炭质页岩软弱夹层为研究对象,开展了原生软岩、层间剪切带和滑带3个演化阶段的矿物组成成分、微结构和不同正应力水平的剪切蠕变力学特性分析。结果表明:软弱夹层在演化过程中,矿物组分发生改变,黏土矿物含量在原生软岩中小于5%,层间剪切带中在5%～10%之间,滑带中大于10%。微结构由致密变得疏松,颗粒间连接力减弱;软弱夹层的蠕变位移和蠕变速率随着剪应力增加而增大,呈非线性关系。在相同剪应力条件下,蠕变位移和蠕变速率的关系为:滑带>层间剪切带>原岩。长期剪切强度逐渐降低,黏聚力的降幅大于内摩擦角,对时间的敏感程度较高。为受软弱夹层控制的层状基岩滑坡的发育发展过程、失稳机制研究提供了重要借鉴意义。
We focus on the weak intercalation of Permian carbonaceous shale and analyze mineral composition, microstructure, and shear creep characteristics of Permian carbonaceous shale under different levels of normal stress during three evolutionary stages:original soft rock, interlayer shear zone, and sliding zone. The analysis results indicate that during the evolutionary process of the weak intercalation stage, the mineral compositions and content of the shale changed, and the clay mineral content gradually increased from less than 5% in the original soft rock stage to 5%-10% in the interlayer shear zone stage, and finally to greater than 10% in the sliding zone stage. The microstructure changed from compact to loose, and the bonding force between the particles was weakened.The creep displacement and the rate increases non-linearly with increasing shear stress. Under identical shear stress, the relationship of the creep displacement and the rate was that the sliding zone was greater than the interlayer shear zone, and the interlayer shear zone was greater than the original soft rock. The long-term shear strength gradually decreased, the drop in cohesion was greater than the angle of internal friction, and the cohesion was more sensitive to time than the angle of internal friction. The conclusions of this paper provided an important reference for the study of the development and mechanism of layered rock landslides controlled by weak intercalations.
We focus on the weak intercalation of Permian carbonaceous shale and analyze mineral composition, microstructure, and shear creep characteristics of Permian carbonaceous shale under different levels of normal stress during three evolutionary stages:original soft rock, interlayer shear zone, and sliding zone. The analysis results indicate that during the evolutionary process of the weak intercalation stage, the mineral compositions and content of the shale changed, and the clay mineral content gradually increased from less than 5% in the original soft rock stage to 5%-10% in the interlayer shear zone stage, and finally to greater than 10% in the sliding zone stage. The microstructure changed from compact to loose, and the bonding force between the particles was weakened.The creep displacement and the rate increases non-linearly with increasing shear stress. Under identical shear stress, the relationship of the creep displacement and the rate was that the sliding zone was greater than the interlayer shear zone, and the interlayer shear zone was greater than the original soft rock. The long-term shear strength gradually decreased, the drop in cohesion was greater than the angle of internal friction, and the cohesion was more sensitive to time than the angle of internal friction. The conclusions of this paper provided an important reference for the study of the development and mechanism of layered rock landslides controlled by weak intercalations.
引文
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[9]MARANINI E,BRIGNOLI M.Creep behavior of a weak rock:experimental characterization[J].International Journal of Rock Mechanics and Mining Science&Geomechanics Abstracts,1999,36(1):127-138.
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[14]DESAI C S,ZHANG D.Viscoplastic model for geologic materials with generalized flow rule[J].International Journal for Numerical and Analytical Methods in Geomechanics,1987,11(6):603-620.
[15]XIAO S F,WANG X F,CHENG Z F,et al.The creep model of the intercalated clay layers and the change of their microstructure during creep[C]//Proceedings of the5th International Congress International Association of Engineering Geology.Rotterdam:A.A.Balkema,1986:471-478.
[16]SAVAGE W Z,VARNES D J.Mechanics of gravitation a spreading of steep-sided ridges[J].Engineering Geology,1987,35:31-36.
[17]孙钧.岩石流变力学及其工程应用研究的若干进展[J].岩石力学与工程学报,2007,26(6):1081-1106.SUN Jun.Rock rheological mechanics and its advance in engineering applications[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(6):1081-1106.
[18]PAUL FOHN,CHRISTIAN CAMPONOVO.Improvements by measuring shear strength of weak layers[J].Instruments and Methods,1996:158-162.
[19]徐鼎平,冯夏庭,崔玉军,等.含层间错动带岩体的破坏模式及其剪切特性研究方法探讨[J].岩土力学,2012,33(1):129-136.XU Ding-ping,FENG Xia-ting,CUI Yu-jun,et al.On failure mode and shear behavior of rock mass with Interlayer staggered zone[J].Rock and Soil Mechanics,2012,33(1):129-136.
[20]ZHU YANBO,YU HONGMING.An improved Mesri creep model for unsaturated weak intercalated soils[J].Journal of Central South University,2014,21(2):4677-4681.
[21]L’HEUREUX JEAN-SEBASTIEN,LONGVA ODDVAR,STEINER ALOIS,et al.Identification of weak layers and their role for the stability of slopes at Finneidfjord,Northern Norway[J].Springer Netherlands,2012,31:321-330.
[22]许江,王威,刘义鑫,等.剪切-渗流作用下煤岩剪断面形态特征试验研究[J].岩土力学,2018,39(12):4313-4324.XU Jiang,WANG Wei,LIU Yi-xin,et al.Experimental study on shear-seepage for coal-rock shear fracture surface morphological characteristics[J].Rock and Soil Mechanics,2018,39(12):4313-4324.
[23]刘泉声,罗慈友,陈自由,等.现场岩体三轴流变试验设备研制[J].岩土力学,2018,39(增刊2):473-479.LIU Quan-sheng,LUO Ci-you,CHEN Zi-you,et al.Development of triaxial rheological testing equipment for in-situ rock mass[J].Rock and Soil Mechanics,2018,39(Suppl.2):473-479.
[24]史存鹏,冯夏庭,江权,等.白鹤滩层间错动带微结构特性及其化学改性初探[J].岩土力学,2013,34(5):1287-1292.SHI Cun-peng,FENG Xia-ting,JIANG Quan,et al.Preliminary study of microstructural properties and chemical modifications of interlayer shear weakness zone in Baihetan[J].Rock and Soil Mechanics,2013,34(5):1287-1292.
[25]李守定,李晓,张年学,等.三峡库区侏罗系易滑地层沉积特征及其对岩石物理力学性质的影响[J].工程地质学报,2004,12(4):385-389.LI Shou-ding,LI Xiao,ZHANG Nian-xue,et al.Sedimentation characteristics of the Jurassic sliding-prone stratum in the Three Gorges Reservoir area and their influence on physical and mechanical properties of rock[J].Journal of Engingeering Geology,2004,12(4):385-389.
[26]徐卫亚,韩国权.高坝洲坝基岩体层间剪切带研究[J].岩石力学与工程学报,1993,15(2):3-15.XU Wei-ya,HAN Huo-quan.Study on the weakenly shearing interlaying zone in Gaobazhou damsite[J].Chinese Journal of Rock Mechanics and Engineering,1993,15(2):3-15.
[27]王洪兴,唐辉明,晏同珍.小浪底库区庙上北滑坡滑带土粘土矿物定向性的X射线衍射研究及其对滑坡的作用[J].水文地质工程地质,2004,24(2):26-29.WANG Hong-xing,TANG Hui-ming,YAN Tong-zhen.Study on X-ray diffraction for the orientability of clay minerals in sliding-soil in the miaoshangbei landslide,Xiaolangdi reservoir area[J].Hydrogeology and Engineering Geology,2004,24(2):26-29.
[2]李滨,王国章,冯振,等.地下采空诱发陡倾层状岩质斜坡失稳机制研究[J].岩石力学与工程学报,2015,34(6):1148-1161.LI Bin,WANG Guo-zhang,FENG Zhen,et al.Failure mechanism of steeply inclined rock slopes induced by underground mining[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(6):1148-1161.
[3]冯振,殷跃平,李滨,等.重庆武隆鸡尾山滑坡视向滑动机制分析[J].岩土力学,2012,33(9):2704-2712.FENG Zhen,YIN Yue-ping,LI Bin,et al.Mechanism analysis of apparent dip landslide of Jiweishan in Wulong,Chongqing[J].Rock and Soil Mechanics,2012,33(9):2704-2712.
[4]殷跃平,康宏达,张颖.链子崖危岩体稳定性分析及锚固工程优化设计[J].岩土工程学报,2000,22(5):599-603.YIN Yue-ping,KANG Hong-da,ZHANG Ying.Stability analysis and optimal anchoring design on Lianziya dangerous rockmass[J].Chinese Journal of Geotechnical Engineering,2000,22(5):599-603.
[5]谷德振.岩体工程地质力学基础[M].北京:科学出版社,1983.GU De-zhen.Foundations of engineering geomechanics of rock mass[M].Beijing:Science Press,1983.
[6]曲永新,徐瑞春.长江葛洲坝工程层间剪切带的研究[C]//全国首届工程地质学术会议论文选集.北京:科学出版社,1979:161-168.QU Yong-xin,XU Rui-chun.Study of interbedding shear zone at Gezhouba project on the Yangtze River[C]//Proceedings of the First Engineering Geology Conference in China.Beijing:Science Press,1979:161-168.
[7]李晓,李守定,陈剑,等.地质灾害形成的内外动力耦合作用机制[J].岩石力学与工程学报,2008,27(9):1792-1806.LI Xiao,LI Shou-ding,CHEN Jian,et al.Coupling effect mechanism of endogenic and exogenic geological processes of geological hazards evolution[J].Chinese Journal of Rock Mechanics and Engineering,2008,27(9):1792-1806.
[8]黎克日,康文法.岩体中泥化夹层的流变试验及其长期强度的确定[J].岩土力学,1983,4(1):39-46.LI Ke-ri,KANG Wen-fa.Creep testing of thin interbedded clayey seams in rock and determination of their longterm strength[J].Rock and Soil Mechanics,1983,4(1):39-46.
[9]MARANINI E,BRIGNOLI M.Creep behavior of a weak rock:experimental characterization[J].International Journal of Rock Mechanics and Mining Science&Geomechanics Abstracts,1999,36(1):127-138.
[10]GRIGGS D T.Creep of rock[J].Journal of Geology,1939,47:225-251.
[11]TAN TIONG KIE,LI KERI.Relaxation and creep properties of thin interbedded clayey seams and their fundamental role in the stability of dams[C]//Proceedings of the Intenational Symposium on Weak Rock.Tokyo,Intenational Society for Rock Mechanics and Rock Engineering,1981:369-374.
[12]PERZYNA P.Fundamental problems in viscoplasticity[J].Advances in Applied Mechanics,1966,9(2):244-368.
[13]ZIENKIEWICZ O C,CORMEAU I C.Viscoplasticityplasticity and creep in elastic solids-a unified numerical solution approach[J].International Journal for Numerical Methods in Engineering,1974,8(4):821-845.
[14]DESAI C S,ZHANG D.Viscoplastic model for geologic materials with generalized flow rule[J].International Journal for Numerical and Analytical Methods in Geomechanics,1987,11(6):603-620.
[15]XIAO S F,WANG X F,CHENG Z F,et al.The creep model of the intercalated clay layers and the change of their microstructure during creep[C]//Proceedings of the5th International Congress International Association of Engineering Geology.Rotterdam:A.A.Balkema,1986:471-478.
[16]SAVAGE W Z,VARNES D J.Mechanics of gravitation a spreading of steep-sided ridges[J].Engineering Geology,1987,35:31-36.
[17]孙钧.岩石流变力学及其工程应用研究的若干进展[J].岩石力学与工程学报,2007,26(6):1081-1106.SUN Jun.Rock rheological mechanics and its advance in engineering applications[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(6):1081-1106.
[18]PAUL FOHN,CHRISTIAN CAMPONOVO.Improvements by measuring shear strength of weak layers[J].Instruments and Methods,1996:158-162.
[19]徐鼎平,冯夏庭,崔玉军,等.含层间错动带岩体的破坏模式及其剪切特性研究方法探讨[J].岩土力学,2012,33(1):129-136.XU Ding-ping,FENG Xia-ting,CUI Yu-jun,et al.On failure mode and shear behavior of rock mass with Interlayer staggered zone[J].Rock and Soil Mechanics,2012,33(1):129-136.
[20]ZHU YANBO,YU HONGMING.An improved Mesri creep model for unsaturated weak intercalated soils[J].Journal of Central South University,2014,21(2):4677-4681.
[21]L’HEUREUX JEAN-SEBASTIEN,LONGVA ODDVAR,STEINER ALOIS,et al.Identification of weak layers and their role for the stability of slopes at Finneidfjord,Northern Norway[J].Springer Netherlands,2012,31:321-330.
[22]许江,王威,刘义鑫,等.剪切-渗流作用下煤岩剪断面形态特征试验研究[J].岩土力学,2018,39(12):4313-4324.XU Jiang,WANG Wei,LIU Yi-xin,et al.Experimental study on shear-seepage for coal-rock shear fracture surface morphological characteristics[J].Rock and Soil Mechanics,2018,39(12):4313-4324.
[23]刘泉声,罗慈友,陈自由,等.现场岩体三轴流变试验设备研制[J].岩土力学,2018,39(增刊2):473-479.LIU Quan-sheng,LUO Ci-you,CHEN Zi-you,et al.Development of triaxial rheological testing equipment for in-situ rock mass[J].Rock and Soil Mechanics,2018,39(Suppl.2):473-479.
[24]史存鹏,冯夏庭,江权,等.白鹤滩层间错动带微结构特性及其化学改性初探[J].岩土力学,2013,34(5):1287-1292.SHI Cun-peng,FENG Xia-ting,JIANG Quan,et al.Preliminary study of microstructural properties and chemical modifications of interlayer shear weakness zone in Baihetan[J].Rock and Soil Mechanics,2013,34(5):1287-1292.
[25]李守定,李晓,张年学,等.三峡库区侏罗系易滑地层沉积特征及其对岩石物理力学性质的影响[J].工程地质学报,2004,12(4):385-389.LI Shou-ding,LI Xiao,ZHANG Nian-xue,et al.Sedimentation characteristics of the Jurassic sliding-prone stratum in the Three Gorges Reservoir area and their influence on physical and mechanical properties of rock[J].Journal of Engingeering Geology,2004,12(4):385-389.
[26]徐卫亚,韩国权.高坝洲坝基岩体层间剪切带研究[J].岩石力学与工程学报,1993,15(2):3-15.XU Wei-ya,HAN Huo-quan.Study on the weakenly shearing interlaying zone in Gaobazhou damsite[J].Chinese Journal of Rock Mechanics and Engineering,1993,15(2):3-15.
[27]王洪兴,唐辉明,晏同珍.小浪底库区庙上北滑坡滑带土粘土矿物定向性的X射线衍射研究及其对滑坡的作用[J].水文地质工程地质,2004,24(2):26-29.WANG Hong-xing,TANG Hui-ming,YAN Tong-zhen.Study on X-ray diffraction for the orientability of clay minerals in sliding-soil in the miaoshangbei landslide,Xiaolangdi reservoir area[J].Hydrogeology and Engineering Geology,2004,24(2):26-29.