基于SCPTU原位状态参数确定方法及液化应用试验研究
|
摘要
状态参数可以有效地评价无黏性土的相对密实度和液化势。然而,目前状态参数的确定主要依赖于室内试验,难以反映现场土层的真实状态。地震波孔压静力触探(SCPTU)测试可以获取土层的原位锥尖阻力、侧壁摩阻力、孔隙水压力与剪切波速等原位参数。本文基于SCPTU测试确定状态参数的研究成果,根据3个工程场地的SCPTU原位测试资料,首先对不同状态参数评估方法进行了比较,其次建立归一化剪切波速V_(s1)与原位状态参数的相关关系,绘制剪切波速与有效应力(V_s-σ′_(v0))平面中状态参数剖面等值线图;提出归一化小应变刚度(G_0/q_c)与状态参数的修正模型。最后应用于无黏性土密实度与液化势的评估中。结果表明:本文提出的2种计算方法能够有效地评估无黏性土的状态参数,并且预测的状态参数可有效地用于评价土体密实状态与液化势的可靠判别。
The state parameter can be used to effectively evaluate the relative density and liquefaction potential of the cohesionless soil. However,at present,the determination of state parameter is mainly dependent on laboratory tests,and it is difficult to reflect the real state of the field. The seismic wave piezocone test(SCPTU) can provide in-situ parameters such as cone tip resistance,sleeve friction resistance,pore water pressure and shear wave velocity. Based on the research results of SCPTU testing to determine the state parameter and SCPTU testing data of the three sites,firstly,the different evaluation methods of state parameter are compared,secondly,the correlation between the normalized shear wave velocity(V_(s1)) and in-situ state parameter is established,and the contour lines of state parameter profile in the plane of the shear wave velocity and the effective vertical stress(Vs-σ′_(v0)) are drawn, thirdly, the revised model of the relationship between normalized small strain stiffness(G_0/q_c) and state parameter has been proposed. Finally,these proposed methods are applied to the evaluation of the density and liquefaction potential of the cohesionless soil. The results show that the two calculation methods proposed in this paper can effectively evaluate the state parameter of the cohesionless soil,and the state parameter evaluated can be effectively used for evaluating the dense state and reliably discriminating liquefaction potential.
The state parameter can be used to effectively evaluate the relative density and liquefaction potential of the cohesionless soil. However,at present,the determination of state parameter is mainly dependent on laboratory tests,and it is difficult to reflect the real state of the field. The seismic wave piezocone test(SCPTU) can provide in-situ parameters such as cone tip resistance,sleeve friction resistance,pore water pressure and shear wave velocity. Based on the research results of SCPTU testing to determine the state parameter and SCPTU testing data of the three sites,firstly,the different evaluation methods of state parameter are compared,secondly,the correlation between the normalized shear wave velocity(V_(s1)) and in-situ state parameter is established,and the contour lines of state parameter profile in the plane of the shear wave velocity and the effective vertical stress(Vs-σ′_(v0)) are drawn, thirdly, the revised model of the relationship between normalized small strain stiffness(G_0/q_c) and state parameter has been proposed. Finally,these proposed methods are applied to the evaluation of the density and liquefaction potential of the cohesionless soil. The results show that the two calculation methods proposed in this paper can effectively evaluate the state parameter of the cohesionless soil,and the state parameter evaluated can be effectively used for evaluating the dense state and reliably discriminating liquefaction potential.
引文
[1]VERDUGO R,ISHIHARA K.The steady state of sandy soils[J].Journal of the Japanese Geotechnical Society Soils and Foundation,1996,36(2):81-91.
[2]CAI Z Y,XIANGSONG L I.Deformation characteristics and critical state of sand[J].Chinese Journal of Geotechnical Engineering,2004,26(5):697-701.
[3]黄茂松,姚仰平,尹振宇,等.土的基本特性及本构关系与强度理论[J].土木工程学报,2016,49(7):9-35.(HUANG Maosong,YAOYangping,YIN Zhenyu,et al.An overview on elementary mechanical behaviors,constitutive modeling and failure criterion of soils[J].China Civil Engineering Journal,2016,49(7):9-35.(in Chinese))
[4]BEEN K,JEFFERIES M G.A state parameter for sands[J].Geotechnique,1985,35(2):99-112.
[5]罗刚,张建民.考虑物态变化的六参数砂土本构模型[J].清华大学学报:自然科学版,2004,44(3):402-405.(LUO Gang,ZHANGJianmin.Six-parameter constitutive model of sand with physical state changes[J].Journal of Tsinghua University:Natural Science,2004,44(3):402-405.(in Chinese))
[6]张卫华,赵成刚,傅方.基于相变状态的砂土本构模型的研究[J].工程地质学报,2013,21(3):337-344.(ZHANG Weihua,ZHAOChenggang,FU Fang.Phase transformation state based constitutive model for sands[J].Journal of Engineering Geology,2013,21(3):337-344.(in Chinese))
[7]陈成,周正明.基于状态参数的砂土非线性弹性模型研究[J].岩石力学与工程学报,2013,32(2):369-376.(CHEN Cheng,ZHOUZhengming.Study of nonlinear elastic model of sand based on state parameters[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(2):369-376.(in Chinese))
[8]姚仰平,余亚妮.基于统一硬化参数的砂土临界状态本构模型[J].岩土工程学报,2011,33(12):1 827-1 832.(YAO Yangping,YU Yani.Extended critical state constitutive model for sand based on unified hardening parameter[J].Chinese Journal of Geotechnical Engineering,2011,33(12):1 827-1 832.(in Chinese))
[9]YANG J,LIU X,GUO Y,et al.A unified framework for evaluating in situ state of sand with varying fines content[J].Géotechnique,2017:1-7.
[10]DO J,HEO S,YOON Y,et al.Evaluating the liquefaction potential of gravel soils with static experiments and steady state approaches[J].KSCE Journal of Civil Engineering,2017,21(3):642-651.
[11]SLADEN J A.Problems with interpretation of sand state from cone penetration test[J].Géotechnique,1989,39(39):323-332.
[12]PLEWES H D,DAVIES M P,JEFFERIES M G,CPT based screening procedure for evaluating liquefaction susceptibility[C]//Proceedings of the 45th Canadian Geotechnical Conference.Toronto,Ont:[s.n.],1992:41-49.
[13]BEEN K,CROOKS J H A,BECKER D E,et al.The cone penetration test in sands:part I,state parameter interpretation[J].Geotechnique,1986,36(2):239-249.
[14]BEEN K,JEFFERIES M G,CROOKS J H A,et al.The cone penetration test in sands:part II,general inference of state[J].Géotechnique,1987,37(37):285-299.
[15]ROBERTSON P K.Estimating in-situ state parameter and friction angle in sandy soils from CPT[C]//Proceedings of the 2nd International Symposium on Cone Penetration Testing.CA,USA:[s.n.],2010:2-43.
[16]SCHNAID F,YU H S.Interpretation of the seismic cone test in granular soils[J].Géotechnique,2007,57(3):265-272.
[17]蔡国军,刘松玉,童立元,等.基于SCPTU的软土最大剪切模量测试分析研究[J].岩土力学,2008,29(9):2 556-2 560.(CAIGuojun,LIU Songyu,TONG Liyuan,et al.Evaluation of maximum shear modulus of soft clay from seismic piezocone tests(SCPTU)[J].Rock and Soil Mechanics,2008,29(9):2 556-2 560.(in Chinese))
[18]BEEN K,JEFFERIES M G.Towards systematic CPTinterpretation[C]//Proceedings of the Wroth Memorial Symposium.Oxford:[s.n.],1992:121-134.
[19]孔令明,罗汀,姚仰平.率相关本构模型的临界状态描述[J].岩土力学,2015,36(9):2 442-2 450.(KONG Lingming,LUO Ting,YAO Yangping.Description of critical state for rate-dependent constitutive models[J].Rock and Soil Mechanics,2015,36(9):2 442-2 450.(in Chinese))
[20]ATKINSON J H.The mechanics of soils and foundations[M].Taylor&Francis:CRC Press,2007:119-134.
[21]ROBERTSON P K.Evaluation of Flow Liquefaction:influence of high stresses[C]//Proceedings of the 3rd International Conference on Performance-based Design in Earthquake Geotechnical Engineering(PBDIII).Vancouver,Canada:[s.n.],2017:1-8.
[22]刘松玉,蔡国军,童立元.现代多功能CPTU技术理论与工程应用[M].北京:科学出版社,2013:212-214.(LIU Songyu,CAI Guojun,TONG Liyuan.Theoretical research and engineering application of digital multifunctional piezocone penetration test[M].Beijing:Science Press,2013:212-214.(in Chinese))
[23]LUNNE T,ROBERTSON P K,POWELL J J M.Cone penetration Testing in Geotechnical Practice[M].London,UK:Chapman and Hall,1997:85-92.
[24]BEEN K,CROOKS J H,JEFFERIES M G.Interpretation of material state from the CPT in sands and clays[C]//Penetration Testing.Thomas Telford,London,UK:[s.n.],1989:215-218.
[25]ROBERTSON P K,WRIDE C E.Evaluating cyclic liquefaction potential using the cone penetration test[J].Canadian Geotechnical Journal,1998,35(3):442-459.
[26]ROBERTSON P K,SASITHARAN S,CUNNING J C,et al.Shear-wave velocity to evaluate in-situ state of Ottawa sand[J].Journal of Geotechnical Engineering,1995,121(3):262-273.
[27]中华人民共和国行业标准编写组.DGJ32/TJ 208-2016岩土工程勘察规范[S].南京:江苏凤凰科学技术出版社,2016.(The Professional Standards Compilation Group of People?s Republic of China.DGJ32/TJ 208-2016 Code for investigation of geotechnical engineering[S].Nanjing:Phoenix Science Press,2016.(in Chinese))
[28]JEFFERIES M G,BEEN K.Soil liquefaction:a critical state approach[M].Taylor&Francis:CRC Press,2006:299-327.
[29]JAMIOLKOWSKI M,PRESTI D C F L,MANASSERO M.Evaluation of relative density and shear strength of sands from CPT and DMT[J].Geotechnical Special Publication,2003,(119):201-238.
[30]YOUD T L.Liquefaction resistance of soils:summary report from the1996 NCEER and 1998 NCEER/NSF workshops on evaluation of liquefaction resistance of soils[J].Journal of Geotechnical and Geoenvironmental Engineering,2001,127(10):817-833.
[2]CAI Z Y,XIANGSONG L I.Deformation characteristics and critical state of sand[J].Chinese Journal of Geotechnical Engineering,2004,26(5):697-701.
[3]黄茂松,姚仰平,尹振宇,等.土的基本特性及本构关系与强度理论[J].土木工程学报,2016,49(7):9-35.(HUANG Maosong,YAOYangping,YIN Zhenyu,et al.An overview on elementary mechanical behaviors,constitutive modeling and failure criterion of soils[J].China Civil Engineering Journal,2016,49(7):9-35.(in Chinese))
[4]BEEN K,JEFFERIES M G.A state parameter for sands[J].Geotechnique,1985,35(2):99-112.
[5]罗刚,张建民.考虑物态变化的六参数砂土本构模型[J].清华大学学报:自然科学版,2004,44(3):402-405.(LUO Gang,ZHANGJianmin.Six-parameter constitutive model of sand with physical state changes[J].Journal of Tsinghua University:Natural Science,2004,44(3):402-405.(in Chinese))
[6]张卫华,赵成刚,傅方.基于相变状态的砂土本构模型的研究[J].工程地质学报,2013,21(3):337-344.(ZHANG Weihua,ZHAOChenggang,FU Fang.Phase transformation state based constitutive model for sands[J].Journal of Engineering Geology,2013,21(3):337-344.(in Chinese))
[7]陈成,周正明.基于状态参数的砂土非线性弹性模型研究[J].岩石力学与工程学报,2013,32(2):369-376.(CHEN Cheng,ZHOUZhengming.Study of nonlinear elastic model of sand based on state parameters[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(2):369-376.(in Chinese))
[8]姚仰平,余亚妮.基于统一硬化参数的砂土临界状态本构模型[J].岩土工程学报,2011,33(12):1 827-1 832.(YAO Yangping,YU Yani.Extended critical state constitutive model for sand based on unified hardening parameter[J].Chinese Journal of Geotechnical Engineering,2011,33(12):1 827-1 832.(in Chinese))
[9]YANG J,LIU X,GUO Y,et al.A unified framework for evaluating in situ state of sand with varying fines content[J].Géotechnique,2017:1-7.
[10]DO J,HEO S,YOON Y,et al.Evaluating the liquefaction potential of gravel soils with static experiments and steady state approaches[J].KSCE Journal of Civil Engineering,2017,21(3):642-651.
[11]SLADEN J A.Problems with interpretation of sand state from cone penetration test[J].Géotechnique,1989,39(39):323-332.
[12]PLEWES H D,DAVIES M P,JEFFERIES M G,CPT based screening procedure for evaluating liquefaction susceptibility[C]//Proceedings of the 45th Canadian Geotechnical Conference.Toronto,Ont:[s.n.],1992:41-49.
[13]BEEN K,CROOKS J H A,BECKER D E,et al.The cone penetration test in sands:part I,state parameter interpretation[J].Geotechnique,1986,36(2):239-249.
[14]BEEN K,JEFFERIES M G,CROOKS J H A,et al.The cone penetration test in sands:part II,general inference of state[J].Géotechnique,1987,37(37):285-299.
[15]ROBERTSON P K.Estimating in-situ state parameter and friction angle in sandy soils from CPT[C]//Proceedings of the 2nd International Symposium on Cone Penetration Testing.CA,USA:[s.n.],2010:2-43.
[16]SCHNAID F,YU H S.Interpretation of the seismic cone test in granular soils[J].Géotechnique,2007,57(3):265-272.
[17]蔡国军,刘松玉,童立元,等.基于SCPTU的软土最大剪切模量测试分析研究[J].岩土力学,2008,29(9):2 556-2 560.(CAIGuojun,LIU Songyu,TONG Liyuan,et al.Evaluation of maximum shear modulus of soft clay from seismic piezocone tests(SCPTU)[J].Rock and Soil Mechanics,2008,29(9):2 556-2 560.(in Chinese))
[18]BEEN K,JEFFERIES M G.Towards systematic CPTinterpretation[C]//Proceedings of the Wroth Memorial Symposium.Oxford:[s.n.],1992:121-134.
[19]孔令明,罗汀,姚仰平.率相关本构模型的临界状态描述[J].岩土力学,2015,36(9):2 442-2 450.(KONG Lingming,LUO Ting,YAO Yangping.Description of critical state for rate-dependent constitutive models[J].Rock and Soil Mechanics,2015,36(9):2 442-2 450.(in Chinese))
[20]ATKINSON J H.The mechanics of soils and foundations[M].Taylor&Francis:CRC Press,2007:119-134.
[21]ROBERTSON P K.Evaluation of Flow Liquefaction:influence of high stresses[C]//Proceedings of the 3rd International Conference on Performance-based Design in Earthquake Geotechnical Engineering(PBDIII).Vancouver,Canada:[s.n.],2017:1-8.
[22]刘松玉,蔡国军,童立元.现代多功能CPTU技术理论与工程应用[M].北京:科学出版社,2013:212-214.(LIU Songyu,CAI Guojun,TONG Liyuan.Theoretical research and engineering application of digital multifunctional piezocone penetration test[M].Beijing:Science Press,2013:212-214.(in Chinese))
[23]LUNNE T,ROBERTSON P K,POWELL J J M.Cone penetration Testing in Geotechnical Practice[M].London,UK:Chapman and Hall,1997:85-92.
[24]BEEN K,CROOKS J H,JEFFERIES M G.Interpretation of material state from the CPT in sands and clays[C]//Penetration Testing.Thomas Telford,London,UK:[s.n.],1989:215-218.
[25]ROBERTSON P K,WRIDE C E.Evaluating cyclic liquefaction potential using the cone penetration test[J].Canadian Geotechnical Journal,1998,35(3):442-459.
[26]ROBERTSON P K,SASITHARAN S,CUNNING J C,et al.Shear-wave velocity to evaluate in-situ state of Ottawa sand[J].Journal of Geotechnical Engineering,1995,121(3):262-273.
[27]中华人民共和国行业标准编写组.DGJ32/TJ 208-2016岩土工程勘察规范[S].南京:江苏凤凰科学技术出版社,2016.(The Professional Standards Compilation Group of People?s Republic of China.DGJ32/TJ 208-2016 Code for investigation of geotechnical engineering[S].Nanjing:Phoenix Science Press,2016.(in Chinese))
[28]JEFFERIES M G,BEEN K.Soil liquefaction:a critical state approach[M].Taylor&Francis:CRC Press,2006:299-327.
[29]JAMIOLKOWSKI M,PRESTI D C F L,MANASSERO M.Evaluation of relative density and shear strength of sands from CPT and DMT[J].Geotechnical Special Publication,2003,(119):201-238.
[30]YOUD T L.Liquefaction resistance of soils:summary report from the1996 NCEER and 1998 NCEER/NSF workshops on evaluation of liquefaction resistance of soils[J].Journal of Geotechnical and Geoenvironmental Engineering,2001,127(10):817-833.