水饱和边坡夹层热-孔隙水-力耦合作用模型及应用
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摘要
为了研究温度对水饱和边坡夹层力学参数的影响,将水饱和边坡夹层视为固-液两相的线弹性体,建立了水饱和边坡夹层热-孔隙水-力耦合作用的力学模型,并推导了其耦合控制方程;采用物理相似模拟的方法,建立了与边坡原型相似的试验模型,研究温度引起的边坡夹层力学参数的变化特征;通过比较分析理论计算结果与模型试验结果,验证了所建立的耦合力学模型的适用性。研究结果表明:孔隙水压力系数和热压力系数是引起水饱和边坡夹层孔隙水压力增加的关键控制因素;孔隙水压力系数取决于孔隙排水压缩特性和固相介质压缩特性,这两者差值越大,孔隙水压力系数越大;孔隙水热膨胀系数和孔隙体积热膨胀系数是影响热压力系数的主要因素,这两者差值越大,热压力系数也越大;边坡夹层孔隙水压力随温度升高呈现出先缓慢增加而后急剧增加的变化特征,而黏聚力和抗剪强度随温度升高而缓慢降低,且孔隙水压力的理论计算结果与试验测试结果吻合良好。因此,水饱和边坡夹层热-孔隙水-力耦合作用的力学模型能较好地反映孔隙水压力在加热升温过程中的变化特征,为科学地预测和控制类似边坡工程的稳定性提供了参考。
To investigate the effect of temperature on mechanical parameters of a weak interlayer in water-saturated slope, the interlayer is regarded as a linear elastic body of coupled solid-liquid phase. A mechanical model for the thermal-pore water-mechanical interaction of the interlayer in water-saturated slope is established, and its coupling control equation is deduced.Using the physical similarity method, an experimental model similar to the slope prototype is established to study the variations of the inerlayer mechanical parameters caused by temperature. The proposed model is verified by comparing the theoretical results with the corresponding experimental results. It is found that the pore water pressure coefficient and thermal expansion coefficient are the key factors causing the increase of pore water pressure in the saturated interlayer. The pore water pressure coefficient depends on the compression characteristics of pore drainage and the solid medium. The larger the difference between these two compression characteristics, the larger the pore water pressure coefficient. Thermal expansion coefficient of pore water and thermal expansion coefficient of pore volume are the main factors affecting thermal pressure coefficient. A larger difference between them can result in a greater thermal pressure coefficient. Pore water pressure in the saturated interlayer slowly increases first and then dramatically increases with the increase of temperature, while the cohesion and shear strength of the saturated interlayer tardily decrease with the increase of temperature. Theoretical values of the saturated interlayer pore water pressure are in good agreement with the results from model test. Therefore, the proposed model can reflect the change characteristics of pore water pressure at different temperatures,which can provide some useful references to predict and control the stability of similar saturated slopes containing a weak interlayer.
To investigate the effect of temperature on mechanical parameters of a weak interlayer in water-saturated slope, the interlayer is regarded as a linear elastic body of coupled solid-liquid phase. A mechanical model for the thermal-pore water-mechanical interaction of the interlayer in water-saturated slope is established, and its coupling control equation is deduced.Using the physical similarity method, an experimental model similar to the slope prototype is established to study the variations of the inerlayer mechanical parameters caused by temperature. The proposed model is verified by comparing the theoretical results with the corresponding experimental results. It is found that the pore water pressure coefficient and thermal expansion coefficient are the key factors causing the increase of pore water pressure in the saturated interlayer. The pore water pressure coefficient depends on the compression characteristics of pore drainage and the solid medium. The larger the difference between these two compression characteristics, the larger the pore water pressure coefficient. Thermal expansion coefficient of pore water and thermal expansion coefficient of pore volume are the main factors affecting thermal pressure coefficient. A larger difference between them can result in a greater thermal pressure coefficient. Pore water pressure in the saturated interlayer slowly increases first and then dramatically increases with the increase of temperature, while the cohesion and shear strength of the saturated interlayer tardily decrease with the increase of temperature. Theoretical values of the saturated interlayer pore water pressure are in good agreement with the results from model test. Therefore, the proposed model can reflect the change characteristics of pore water pressure at different temperatures,which can provide some useful references to predict and control the stability of similar saturated slopes containing a weak interlayer.
引文
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[10]LIZáRRAGA J J,FRATTINI P,CROSTA G B,et al.Regional-scale modelling of shallow landslides with different initiation mechanisms:sliding versus liquefaction[J].Engineering Geology,2017,228(10):346-356.
[11]KUMAR M,RANA S,PANT P D,et al.Slope stability analysis of Balia Nala landslide,Kumaun Lesser Himalaya,Nainital,Uttarakhand,India[J].Journal of Rock Mechanics and Geotechnical Engineering,2017,9(1):150-158.
[12]CHO S E.Stability analysis of unsaturated soil slopes considering water-air flow caused by rainfall infiltration[J].Engineering Geology,2016,211:184-197.
[13]MARTELLONI G,BAGNOLI F,GUARINO A.A 3Dmodel for rain-induced landslides based on molecular dynamics with fractal and fractional water diffusion[J].Communications in Nonlinear Science and Numerical Simulation,2017,50(9):311-329.
[14]CECINATO F.The role of frictional heating in the development of catastrophic landslides[D].Southampton:University of Southampton,2009.
[15]CECINATO F,ZERVOS A,VEVEAKIS E.A thermomechanical model for the catastrophic collapse of large landslides[J].International Journal for Numerical and Analytical Methods in Geomechanics,2011,35(14):1507-1535.
[16]GHABEZLOO S,SULEM J.Temperature induced pore fluid pressurization in geomaterials[J].Italian Geotechnical Journal,2010,(1):29-43.
[17]GHABEZLOO S,SULEM J.Stress dependent thermal pressurization of a fluid-saturated rock[J].Rock Mechanics and Rock Engineering,2009,42(1):1-24.
[18]GUAYACáN C L M,GHABEZLOO S,SULEM J,et al.Effect of anisotropy and hydro-mechanical couplings on pore pressure evolution during tunnel excavation in low-permeability ground[J].International Journal of Rock Mechanics&Mining Sciences,2017,97:1-14.
[19]GHABEZLOO S.Micromechanical analysis of the effect of porosity on the thermal expansion coefficient of heterogeneous porous materials[J].International Journal of Rock Mechanics&Mining Sciences,2017,55:97-101.
[20]BAI B,GUO L J,HAN S.Pore pressure and consolidation of saturated silt clay induced by progressively heating/cooling[J].Mechanics of Materials,2014,75:84-94.
[21]MOEINI V,ASHRAFI F,KARRI M,et al.Calculation of thermal pressure coefficient of dense fluids using the linear isotherm regularity[J].Journal of Physics:Condensed Matter,2008,20:1-8.
[22]BISHOP A W.The influence of system compressibility on the observed pore pressure response to an undrained change in stress in saturated rock[J].Geotechnique,1976,26(2):371-375.
[23]DETOURNAY E,CHENG A H D.Fundamentals of Poroelasticity[M].Berlin:Fairhurst,1993:113-171.
[24]TERZAGHI K.Theoretical soil mechanics[M].Boston:Wiley,1943.
[25]MC TIGUE D F.Thermoelastic response of fluidsaturated porous rock[J].Journal of Geophysical Research,1986,91(B9):9533-9542.
[26]SKEMPTON A W,AMICE D S C.The pore-pressure coefficients A and B[J].Geotechnique,1954,4:143-147.
[27]HILL R.The elastic behavior of crystalline aggregate[J].Proceedings of the Physical Society,London,1952,65:349-354.
[28]PALCIAUSKAS V V,DOMENICO P A.Characterization of drained and undrained response of thermally loaded repository rocks[J].Water Resources Research,1982,18(2):281-290
[29]BASS J D.Elasticity of minerals,glasses,and melts,in mineral physics and crystallography:a handbook of physical constants[M].Washington D C:American Geophysical Union,1995:29-63.
[30]BERRYMAN J.Mixture theories for rock properties,in rock physics&phase relations:a handbook of physical constants[M].Washington D C:American Geophysical Union,1995:205-228.
[31]中华人民共和国水利部.GB/T50123-1999土工试验方法标准[S].北京:中国标准出版社,1999.Ministry of Water Resources of the people’s Republic of China.GB/T50123-1999.Standard for test method[S].Beijing:Standards Press of China,1999.
[32]MASAHIRO S,KENJI W,TAISUKE S,et al.Dynamic behavior of slope models with various slope inclinations[J].Soils and Foundations,2014,55(1):127-142.
[33]范刚,张建经,付晓,等.含泥化夹层顺层岩质边坡动力响应大型振动台试验研究[J].岩石力学与工程学报,2015,34(9):1750-1757.FAN Gang,ZHANG Jian-jing,FU Xiao,et al.Largescale shaking table test on dynamic response of bedding rock slopes with silt intercalation[J].Chinses Journal of Rock Mechanics and Engineering,2015,34(9):1750-1757.
[34]HAKRO M R,HARAHAP I S H.Laboratory experiments on rainfall induced flowslide from pore pressure and moisture content measurements[J].Natural Hazards&Earth System Sciences Discussions,2015(3):1575-1613.
[2]宋娅芬,陈从新,郑允,等.缓倾软硬岩互层边坡变形破坏机制模型试验研究[J].岩土力学,2015,36(2):487-494.SONG Ya-fen,CHEN Cong-xin,ZHENG Yun,et al.Model experimental study of deformation and failure mechanism of low-angled slopes with interbedding of soft and hard rocks[J].Rock and Soil Mechanics,2015,36(2):487-494.
[3]吴红刚,马惠民,侯殿英,等.青海高原“龙穆尔沟”红层滑坡变形机制的地质分析与模型试验研究[J].岩石力学与工程学报,2010,29(10):2091-2102.WU Hong-gang,MA Hui-min,HOU Dian-ying,et al.Geological analysis and model experimental study of deformation mechanism of Ditch-Moore red bed landslide at Qinghai plateau[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(10):2091-2102.
[4]YIN Y P,LI B,WANG W P,et al.Mechanism of the December 2015 Catastrophic landslide at the Shenzhen landfill and controlling geotechnical risks of urbanization[J].Engineering,2016,2(2):230-249.
[5]覃小华,刘东升,宋强辉,等.强降雨条件下考虑饱和渗透系数变异性的基岩型层状边坡可靠度分析[J].岩土工程学报,2017,39(6):1065-1073.QIN Xiao-hua,LIU Dong-sheng,SONG Qiang-hui,et al.Reliability analysis of bedrock laminar slope stability considering variability of saturated hydraulic conductivity of soil under heavy rainfall[J].Chinese Journal of Geotechnical Engineering,2017,39(6):1065-1073.
[6]蒋中明,熊小虎,曾铃.基于FLAC3D平台的边坡非饱和降雨入渗分析[J].岩土力学,2014,35(3):855-861.JIANG Zhong-ming,XIONG Xiao-hu,ZENG Ling.Unsaturated seepage analysis of slope under rainfall condition based on FLAC3D[J].Rock and Soil Mechanics,2014,35(3):855-861.
[7]牛文杰,叶为民,刘绍刚,等.考虑饱和-非饱和渗流的土坡极限分析[J].岩土力学,2009,30(8):2477-2482.NIU Wen-jie,YE Wei-min,LIU Shao-gang,et al.Limit analysis of a soil slope considering saturated-unsaturated seepage[J].Rock and Soil Mechanics,2009,30(8):2477-2482.
[8]张旭,谭卓英,周春梅.库水位变化下滑坡渗流机制与稳定性分析[J].岩石力学与工程学报,2016,35(4):713-723.ZHANG Xu,TAN Zhuo-ying,ZHOU Chun-mei.Seepage and stability analysis of landslide under the change of reservoir water levels[J].Chinese Journal of Rock Mechanics and Engineering,2016,35(4):713-723.
[9]熊勇林,朱合华,叶冠林,等.降雨入渗引起非饱和土边坡破坏的水-土-气三相渗流-变形耦合有限元分析[J].岩土力学,2017,38(1):284-290.XIONG Yong-lin,ZHU He-hua,YE Guan-lin,et al.Analysis of failure of unsaturated soil slope due to rainfall based on soil-water-air seepage-deformation coupling FEM[J].Rock and Soil Mechanics,2017,38(1):284-290.
[10]LIZáRRAGA J J,FRATTINI P,CROSTA G B,et al.Regional-scale modelling of shallow landslides with different initiation mechanisms:sliding versus liquefaction[J].Engineering Geology,2017,228(10):346-356.
[11]KUMAR M,RANA S,PANT P D,et al.Slope stability analysis of Balia Nala landslide,Kumaun Lesser Himalaya,Nainital,Uttarakhand,India[J].Journal of Rock Mechanics and Geotechnical Engineering,2017,9(1):150-158.
[12]CHO S E.Stability analysis of unsaturated soil slopes considering water-air flow caused by rainfall infiltration[J].Engineering Geology,2016,211:184-197.
[13]MARTELLONI G,BAGNOLI F,GUARINO A.A 3Dmodel for rain-induced landslides based on molecular dynamics with fractal and fractional water diffusion[J].Communications in Nonlinear Science and Numerical Simulation,2017,50(9):311-329.
[14]CECINATO F.The role of frictional heating in the development of catastrophic landslides[D].Southampton:University of Southampton,2009.
[15]CECINATO F,ZERVOS A,VEVEAKIS E.A thermomechanical model for the catastrophic collapse of large landslides[J].International Journal for Numerical and Analytical Methods in Geomechanics,2011,35(14):1507-1535.
[16]GHABEZLOO S,SULEM J.Temperature induced pore fluid pressurization in geomaterials[J].Italian Geotechnical Journal,2010,(1):29-43.
[17]GHABEZLOO S,SULEM J.Stress dependent thermal pressurization of a fluid-saturated rock[J].Rock Mechanics and Rock Engineering,2009,42(1):1-24.
[18]GUAYACáN C L M,GHABEZLOO S,SULEM J,et al.Effect of anisotropy and hydro-mechanical couplings on pore pressure evolution during tunnel excavation in low-permeability ground[J].International Journal of Rock Mechanics&Mining Sciences,2017,97:1-14.
[19]GHABEZLOO S.Micromechanical analysis of the effect of porosity on the thermal expansion coefficient of heterogeneous porous materials[J].International Journal of Rock Mechanics&Mining Sciences,2017,55:97-101.
[20]BAI B,GUO L J,HAN S.Pore pressure and consolidation of saturated silt clay induced by progressively heating/cooling[J].Mechanics of Materials,2014,75:84-94.
[21]MOEINI V,ASHRAFI F,KARRI M,et al.Calculation of thermal pressure coefficient of dense fluids using the linear isotherm regularity[J].Journal of Physics:Condensed Matter,2008,20:1-8.
[22]BISHOP A W.The influence of system compressibility on the observed pore pressure response to an undrained change in stress in saturated rock[J].Geotechnique,1976,26(2):371-375.
[23]DETOURNAY E,CHENG A H D.Fundamentals of Poroelasticity[M].Berlin:Fairhurst,1993:113-171.
[24]TERZAGHI K.Theoretical soil mechanics[M].Boston:Wiley,1943.
[25]MC TIGUE D F.Thermoelastic response of fluidsaturated porous rock[J].Journal of Geophysical Research,1986,91(B9):9533-9542.
[26]SKEMPTON A W,AMICE D S C.The pore-pressure coefficients A and B[J].Geotechnique,1954,4:143-147.
[27]HILL R.The elastic behavior of crystalline aggregate[J].Proceedings of the Physical Society,London,1952,65:349-354.
[28]PALCIAUSKAS V V,DOMENICO P A.Characterization of drained and undrained response of thermally loaded repository rocks[J].Water Resources Research,1982,18(2):281-290
[29]BASS J D.Elasticity of minerals,glasses,and melts,in mineral physics and crystallography:a handbook of physical constants[M].Washington D C:American Geophysical Union,1995:29-63.
[30]BERRYMAN J.Mixture theories for rock properties,in rock physics&phase relations:a handbook of physical constants[M].Washington D C:American Geophysical Union,1995:205-228.
[31]中华人民共和国水利部.GB/T50123-1999土工试验方法标准[S].北京:中国标准出版社,1999.Ministry of Water Resources of the people’s Republic of China.GB/T50123-1999.Standard for test method[S].Beijing:Standards Press of China,1999.
[32]MASAHIRO S,KENJI W,TAISUKE S,et al.Dynamic behavior of slope models with various slope inclinations[J].Soils and Foundations,2014,55(1):127-142.
[33]范刚,张建经,付晓,等.含泥化夹层顺层岩质边坡动力响应大型振动台试验研究[J].岩石力学与工程学报,2015,34(9):1750-1757.FAN Gang,ZHANG Jian-jing,FU Xiao,et al.Largescale shaking table test on dynamic response of bedding rock slopes with silt intercalation[J].Chinses Journal of Rock Mechanics and Engineering,2015,34(9):1750-1757.
[34]HAKRO M R,HARAHAP I S H.Laboratory experiments on rainfall induced flowslide from pore pressure and moisture content measurements[J].Natural Hazards&Earth System Sciences Discussions,2015(3):1575-1613.