冻土不同拉伸试验强度差异性研究
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摘要
冻土拉伸强度是冻土工程设计的重要指标,在试验中发现冻土单轴拉伸强度和四点弯曲拉伸强度值不一致。为此采用细观数值方法,假设细观材料参数符合Weibull分布,采用损伤模型,宏观材料性能符合线弹性假设,分别模拟了单轴拉伸试验和四点弯曲拉伸试验。引入非局部化理论,解释了其强度差异来源于材料均质度,并且定量地给出了材料特征长度和均质度之间的关系。为冻土拉伸强度测量和冻土设计提供理论基础。
The tensile strength of frozen soils is an important index in engineering design. In the tests, it is found that the uniaxial tensile strength of frozen soils is inconsistent with the four-point bending tensile strength. For this reason, the mesoscopic numerical method, assuming that the parameters of mesoscopic materials conform to the Weibull distribution, and the damage model are adopted. The properties of macroscopic materials conform to the linear elastic hypothesis. The uniaxial tensile tests and the four-point bending tensile tests are simulated respectively. By introducing the theory of non-localization, it is explained that the strength difference comes from the homogeneity of the materials, and the relationship between the characteristic length of the materials and the homogeneity is quantitatively given. It provides a theoretical basis for measuring the tensile strength of frozen soils and designing the frozen soils.
The tensile strength of frozen soils is an important index in engineering design. In the tests, it is found that the uniaxial tensile strength of frozen soils is inconsistent with the four-point bending tensile strength. For this reason, the mesoscopic numerical method, assuming that the parameters of mesoscopic materials conform to the Weibull distribution, and the damage model are adopted. The properties of macroscopic materials conform to the linear elastic hypothesis. The uniaxial tensile tests and the four-point bending tensile tests are simulated respectively. By introducing the theory of non-localization, it is explained that the strength difference comes from the homogeneity of the materials, and the relationship between the characteristic length of the materials and the homogeneity is quantitatively given. It provides a theoretical basis for measuring the tensile strength of frozen soils and designing the frozen soils.
引文
[1]V N RAZBEGIN S S V,MAKSIMYAK R V,SADOVSKII A V.Mechanical properties of frozen soils[J].Soil Mechanics and Foundation Engineering,1996,33(2):35-45.
[2]李宁,程国栋,徐学祖,等.冻土力学的研究进展与思考[J].力学进展,2001,31(1):95-102.(LI Ning,CHENGGuo-dong,XU Xue-zu,et al.The advance and review on frozen soil mechanica[J].Advances in Mechanics,2001,31(1):95-102.(in Chinese))
[3]孟祥连.青藏铁路多年冻土工程地质勘察[J].铁道勘察,2006,32(3):28-31.(MENG Xiang-lian.The Geological prospecting for the permaforst engineering in the Qinghai-Tibet railway[J].Railway Investigation and Surveying,2006,32(3):28-31.(in Chinese))
[4]于长一.地铁联络通道冻结法施工数值模拟分析[D].天津大学,2014.(YU Chang-yi.Numerical simulation analysis of freezing method construction of metro communication channel[D].Tianjin University,2014.(in Chinese))
[5]叶荣华,刘干斌,叶俊能.宁波轨道交通人工冻土物理力学特性试验研究[J].工程勘察,2011,39(8):19-23.(YERong-hua,LIU Gan-bin,YE Jun-neng.Experimental study on physical and mechanical properties of artificial frozen soil in Nningbo rail transit[J].Geotechnical Investigation&Surveying,2011,39(8):19-23.(in Chinese))
[6]TAMRAKAR S,MITACHI T,TOYOSAWA Y,et al.Tensile strength of compacted and saturated soils using newly developed tensile strength measuring apparatus[J].Soils and Foundations,2005,45(6):103-110.
[7]沈忠言,王家澄,彭万巍,等.单轴受拉时冻土结构变化及其机理初析[J].冰川冻土,1996(3):72-77.(SHENZhong-yan,WANG Jia-cheng,PENG Wan-wei,et al.Change in structures and its mechanisms of frozen soil under uniaxial tensile[J]Journal of Glaciology and Geocryology,1996(3):72-77.(in Chinese))
[8]ZHOU G,HU K,ZHAO X,et al.Laboratory investigation on tensile strength characteristics of warm frozen soils[J].Cold Regions Science and Technology,2015,113:81-90.
[9]孙卓.冻土断裂力学应力强度因子的数值模拟计算[D].大连:大连理工大学,2006.(SUN Zhuo.The numerical simulation of stress intensity factor in fracture mechanics of frozen soil[D].Dalian:Dalian University of Technology,2006.(in Chinese))
[10]FARRELL D A,GREACEN E L,LARSON W E.The effect of water content on axial strain in a loam soil under tension and compression[J].Soil Science Society of America Journal,1967,31(4):445-450.
[11]DAI F,XIA K,TANG L.Rate dependence of the flexural tensile strength of Laurentian granite[J].International Journal of Rock Mechanics and Mining Sciences,2010,47(3):469-475.
[12]ISUPOV L,MIKHAILOV S E.A comparative analysis of several nonlocal fracture criteria[J].Archive of Applied Mechanics,1998,68(9):597-612.
[13]CHRIST M,PARK J-B.Laboratory determination of strength properties of frozen rubber-sand mixtures[J].Cold Regions Science and Technology,2010,60(2):169-175.
[2]李宁,程国栋,徐学祖,等.冻土力学的研究进展与思考[J].力学进展,2001,31(1):95-102.(LI Ning,CHENGGuo-dong,XU Xue-zu,et al.The advance and review on frozen soil mechanica[J].Advances in Mechanics,2001,31(1):95-102.(in Chinese))
[3]孟祥连.青藏铁路多年冻土工程地质勘察[J].铁道勘察,2006,32(3):28-31.(MENG Xiang-lian.The Geological prospecting for the permaforst engineering in the Qinghai-Tibet railway[J].Railway Investigation and Surveying,2006,32(3):28-31.(in Chinese))
[4]于长一.地铁联络通道冻结法施工数值模拟分析[D].天津大学,2014.(YU Chang-yi.Numerical simulation analysis of freezing method construction of metro communication channel[D].Tianjin University,2014.(in Chinese))
[5]叶荣华,刘干斌,叶俊能.宁波轨道交通人工冻土物理力学特性试验研究[J].工程勘察,2011,39(8):19-23.(YERong-hua,LIU Gan-bin,YE Jun-neng.Experimental study on physical and mechanical properties of artificial frozen soil in Nningbo rail transit[J].Geotechnical Investigation&Surveying,2011,39(8):19-23.(in Chinese))
[6]TAMRAKAR S,MITACHI T,TOYOSAWA Y,et al.Tensile strength of compacted and saturated soils using newly developed tensile strength measuring apparatus[J].Soils and Foundations,2005,45(6):103-110.
[7]沈忠言,王家澄,彭万巍,等.单轴受拉时冻土结构变化及其机理初析[J].冰川冻土,1996(3):72-77.(SHENZhong-yan,WANG Jia-cheng,PENG Wan-wei,et al.Change in structures and its mechanisms of frozen soil under uniaxial tensile[J]Journal of Glaciology and Geocryology,1996(3):72-77.(in Chinese))
[8]ZHOU G,HU K,ZHAO X,et al.Laboratory investigation on tensile strength characteristics of warm frozen soils[J].Cold Regions Science and Technology,2015,113:81-90.
[9]孙卓.冻土断裂力学应力强度因子的数值模拟计算[D].大连:大连理工大学,2006.(SUN Zhuo.The numerical simulation of stress intensity factor in fracture mechanics of frozen soil[D].Dalian:Dalian University of Technology,2006.(in Chinese))
[10]FARRELL D A,GREACEN E L,LARSON W E.The effect of water content on axial strain in a loam soil under tension and compression[J].Soil Science Society of America Journal,1967,31(4):445-450.
[11]DAI F,XIA K,TANG L.Rate dependence of the flexural tensile strength of Laurentian granite[J].International Journal of Rock Mechanics and Mining Sciences,2010,47(3):469-475.
[12]ISUPOV L,MIKHAILOV S E.A comparative analysis of several nonlocal fracture criteria[J].Archive of Applied Mechanics,1998,68(9):597-612.
[13]CHRIST M,PARK J-B.Laboratory determination of strength properties of frozen rubber-sand mixtures[J].Cold Regions Science and Technology,2010,60(2):169-175.