循环荷载下堆石料应力变形特性研究
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摘要
基于不同堆石料的多组大型静、动三轴试验,揭示了堆石料的特殊应力变形特性。试验发现,基于Rowe应力剪胀理论所建立的堆石料本构模型将明显低估堆石料的剪缩特性。堆石料的破坏和剪胀线在p-q面上并不是一条直线,剪胀线Md向左上方翘曲,而破坏线Mf则向右下方微曲,随着应力水平的提高,剪胀线Md逐渐接近甚至超过破坏线Mf。动应力和围压之比越大,堆石料的永久剪切和体积变形越大;随着固结应力比的增大,堆石料的永久剪切变形增大,体积变形减小;循环荷载的前几周,堆石料的永久剪切和体积变形的增加较标准砂大,随着循环荷载周数增加,堆石料硬化现象也较标准砂明显。在振动过程中,不论是何种岩质和级配的堆石料一直表现为体积收缩,未出现剪胀;堆石料在固结、静力三轴剪切和振动三轴试验过程中均产生明显的颗粒破碎,颗粒破碎率的大小与堆石料的母岩、级配以及围压等因素相关。围压增大,静力三轴剪切引起的颗粒破碎率随之增大,而单纯由振动三轴试验引起的颗粒破碎率则相应降低。堆石料的颗粒破碎,使其剪胀性降低,剪缩性增大,堆石料所表现出的特殊破坏和剪胀规律显然与其颗粒破碎密切相关。堆石料筑坝材料经先期循环荷载作用后,再次经受循环荷载作用时,其抵抗变形能力明显提高。
Based on a series of static and dynamic tri-axial tests on different rockfill,the special stress and deformation behaviors of rockfill are revealed.It is found that the classic Rowe's stress dilatancy theory will be obviously underestimated by the relevant constitutive models established based on the Rowe's theory.Being not straight,in the p-q plane,the dilantancy line Md buckles to the upper-left,while the failure line Mf is slightly bent to the top-left.With the increase of the stress level,Md will be gradually close to and even exceed Mf.The permanent shear deformation and volume deformation accordingly increase with the increase of the ratio of dynamic stress to cell pressure;differently with the increase of ever shear volume,the volume deformation accordingly decreases with the increase of consolidation stress ratio.In the first cycle of cyclic loadings,the accretion of permanent shear deformation and volume deformation is larger than that of standard sand,and with the increase of cycles,the hardening of the rockfill is also more evident.During the dynamic tests,shrinkage occurs instead of dilantancy no matter what pedogenic rock and gradation are.There obviously occurs particle breakage during consolidation,static and dynamic tri-axial tests.The ratio of particle breakage has close relation with the pedogenic rock,gradation and cell pressure.In the static tri-axial tests,the ratio of particle breakage increases with the increase of the cell pressure,but decreases in the dynamic ones.Obviously,the particle breakage will decrease the shear dilantancy and increase the shear shrinkage.The special failure mechanism of rockfill and the shear dilantancy have close relation with the particle breakage.Previous cyclic loading will obviously raise the capability of resistance of rockfill to the deformation.
Based on a series of static and dynamic tri-axial tests on different rockfill,the special stress and deformation behaviors of rockfill are revealed.It is found that the classic Rowe's stress dilatancy theory will be obviously underestimated by the relevant constitutive models established based on the Rowe's theory.Being not straight,in the p-q plane,the dilantancy line Md buckles to the upper-left,while the failure line Mf is slightly bent to the top-left.With the increase of the stress level,Md will be gradually close to and even exceed Mf.The permanent shear deformation and volume deformation accordingly increase with the increase of the ratio of dynamic stress to cell pressure;differently with the increase of ever shear volume,the volume deformation accordingly decreases with the increase of consolidation stress ratio.In the first cycle of cyclic loadings,the accretion of permanent shear deformation and volume deformation is larger than that of standard sand,and with the increase of cycles,the hardening of the rockfill is also more evident.During the dynamic tests,shrinkage occurs instead of dilantancy no matter what pedogenic rock and gradation are.There obviously occurs particle breakage during consolidation,static and dynamic tri-axial tests.The ratio of particle breakage has close relation with the pedogenic rock,gradation and cell pressure.In the static tri-axial tests,the ratio of particle breakage increases with the increase of the cell pressure,but decreases in the dynamic ones.Obviously,the particle breakage will decrease the shear dilantancy and increase the shear shrinkage.The special failure mechanism of rockfill and the shear dilantancy have close relation with the particle breakage.Previous cyclic loading will obviously raise the capability of resistance of rockfill to the deformation.
引文
[1]ROWE P W.The stress-dilatancy relation for static equilibrium of an assembly of particles in contact[C]//Proceedings of Royal Society of London,Series A,Mathematical and Physical Sciences,Volume 269.London,1962:500–527.
[2]郭熙灵,胡辉,包承纲.堆石料颗粒破碎对剪胀性及抗剪强度的影响[J].岩土工程学报,1997,19(3):83–88.(GUO Xi-ling,HU Hui,BAO Cheng-gan.Experimental studies of the effects of grain breakage on the dilatancy and shear strength of rock fill[J].Chinese Journal of Geotechnical Engineering,1997,19(3):83–88.(in Chinese))
[3]程展林,丁红顺,吴良平.粗粒土试验研究[J].岩土工程学报,2007,29(8):1151–1158.(CHENG Zhan-lin,DING Hong-shun,WU Liang-ping.Experimental study on mechnical behaviour of granular material[J].Chinese Journal of Geotechnical Engineering,2007,29(8):1151–1158.(in Chinese))
[4]刘汉龙,秦红玉,高玉峰,等.堆石粗粒料颗粒破碎试验研究[J].岩土力学,2005,26(4):562–566.(LIU Han-long,QIN Hong-yu,GAO Yu-Feng,et al.Experimental study on particle breakage of rockfill and coarse aggregates[J].Rock and Soil Mechanics,2005,26(4):562–566.(in Chinese))
[5]柏树田,崔亦昊.堆石的力学性质[J].水力发电学报,1997(3):21–29.(BAI Shu-tian,CUI Yi-hao.The mechanical properties of rockfill[J].Journal of Hydroelectric Engineering,1997(3):21–29.(in Chinese))
[6]孙德安,姚仰平.粒状材料的一个实用弹塑性模型[J].岩石力学与工程学报,2002,21(8):1147–1152.(SUN De-an,YAO Yang-ping.Practical elastoplastic model for granular materials[J].Chinese Journal of Rock Mechanics and Engineering,2002,21(8):1147–1152.(in Chinese))
[7]张丙印,贾延安,张宗亮.堆石体修正Rowe剪胀方程与南水模型[J].岩土工程学报,2007,29(10):1143–1148.(ZHANG Bing-yin,JIA Yan-an,ZHANG Zong-liang.Modified Rowe’s dilatancy law of rockfill and Shen Zhujiang’s double yield surfaces elastoplastic model[J].Chinese Journal of Geotechnical Engineering,2007,29(10):1143–1148.(in Chinese))
[8]BOLTON M D.The strength and dilatancy of sands[J].Geotechnique,1986,36(1):65–78.
[9]SL237—1999土工试验规程[S].1999.(SL237—1999 Specification of soil test[S].1999.(in Chinese))
[10]陈生水,沈珠江,郦能惠.复杂应力路径下无粘性土的弹塑性数值模拟[J].岩土工程学报,1995,17(2):20–28.(CHEN Sheng-shui,SHEN Zhu-jiang,LI Neng-hui.A elastoplastic model for cohesionless soils under complex stress paths[J].Chinese Journal of Geotechnical Engineering,1995,17(2):20–28.(in Chinese))
[11]陈生水,霍家平,章为民.汶川“5.12”地震对紫坪铺混凝土面板坝的影响及原因分析[J].岩土工程学报,2008,30(6):795–801.(CHEN Sheng-shui,HUO Jia-ping,ZHANG Wei-min.Analysis of effects of“5.12”Wenchuan Earthquake on Zipingpu Concrete Face Rock-fill Dam[J].Chinese Journal of Geotechnical Engineering,2008,30(6):795–801.(in Chinese))
[2]郭熙灵,胡辉,包承纲.堆石料颗粒破碎对剪胀性及抗剪强度的影响[J].岩土工程学报,1997,19(3):83–88.(GUO Xi-ling,HU Hui,BAO Cheng-gan.Experimental studies of the effects of grain breakage on the dilatancy and shear strength of rock fill[J].Chinese Journal of Geotechnical Engineering,1997,19(3):83–88.(in Chinese))
[3]程展林,丁红顺,吴良平.粗粒土试验研究[J].岩土工程学报,2007,29(8):1151–1158.(CHENG Zhan-lin,DING Hong-shun,WU Liang-ping.Experimental study on mechnical behaviour of granular material[J].Chinese Journal of Geotechnical Engineering,2007,29(8):1151–1158.(in Chinese))
[4]刘汉龙,秦红玉,高玉峰,等.堆石粗粒料颗粒破碎试验研究[J].岩土力学,2005,26(4):562–566.(LIU Han-long,QIN Hong-yu,GAO Yu-Feng,et al.Experimental study on particle breakage of rockfill and coarse aggregates[J].Rock and Soil Mechanics,2005,26(4):562–566.(in Chinese))
[5]柏树田,崔亦昊.堆石的力学性质[J].水力发电学报,1997(3):21–29.(BAI Shu-tian,CUI Yi-hao.The mechanical properties of rockfill[J].Journal of Hydroelectric Engineering,1997(3):21–29.(in Chinese))
[6]孙德安,姚仰平.粒状材料的一个实用弹塑性模型[J].岩石力学与工程学报,2002,21(8):1147–1152.(SUN De-an,YAO Yang-ping.Practical elastoplastic model for granular materials[J].Chinese Journal of Rock Mechanics and Engineering,2002,21(8):1147–1152.(in Chinese))
[7]张丙印,贾延安,张宗亮.堆石体修正Rowe剪胀方程与南水模型[J].岩土工程学报,2007,29(10):1143–1148.(ZHANG Bing-yin,JIA Yan-an,ZHANG Zong-liang.Modified Rowe’s dilatancy law of rockfill and Shen Zhujiang’s double yield surfaces elastoplastic model[J].Chinese Journal of Geotechnical Engineering,2007,29(10):1143–1148.(in Chinese))
[8]BOLTON M D.The strength and dilatancy of sands[J].Geotechnique,1986,36(1):65–78.
[9]SL237—1999土工试验规程[S].1999.(SL237—1999 Specification of soil test[S].1999.(in Chinese))
[10]陈生水,沈珠江,郦能惠.复杂应力路径下无粘性土的弹塑性数值模拟[J].岩土工程学报,1995,17(2):20–28.(CHEN Sheng-shui,SHEN Zhu-jiang,LI Neng-hui.A elastoplastic model for cohesionless soils under complex stress paths[J].Chinese Journal of Geotechnical Engineering,1995,17(2):20–28.(in Chinese))
[11]陈生水,霍家平,章为民.汶川“5.12”地震对紫坪铺混凝土面板坝的影响及原因分析[J].岩土工程学报,2008,30(6):795–801.(CHEN Sheng-shui,HUO Jia-ping,ZHANG Wei-min.Analysis of effects of“5.12”Wenchuan Earthquake on Zipingpu Concrete Face Rock-fill Dam[J].Chinese Journal of Geotechnical Engineering,2008,30(6):795–801.(in Chinese))
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