基于结构性黄土联合强度的邓肯–张非线性本构模型
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摘要
基于Mohr–Coulomb强度准则建立的邓肯–张非线性本构模型可以较好地反映土体抗剪强度特性,但是不适宜反映土体的抗拉强度特性。为了合理反映结构性黄土的抗拉强度,首先,通过在邓肯–张非线性本构模型中引入联合强度准则,基于联合强度准则重新确定了土的强度(1 3?-?)f,从而对破坏应力比Rf进行了修正;然后,用修正后的破坏应力比Rf重新确定了切线变形模量Et;最后,用修正后的切线变形模量Et对切线泊松比νt进行了修正,从而建立了基于联合强度理论的邓肯–张模非线性本构模型,为邓肯–张非线性本构模型在结构性黄土边坡的稳定性研究中,合理考虑结构性黄土的抗拉强度特性的作用提供了一种新的方法和途径。
The Duncan-Chang nonlinear model based on the Mohr-Coulomb strength criterion can better reflect the shear strength characteristics of the soil, but it is not suitable to reflect the tensile strength characteristics of the soil. In order to reflect the tensile strength of the structural loess reasonably, firstly, the strength of soil is re-determined by introducing the joint strength criterion into the Duncan-Chang nonlinear constitutive model, and the failure stress ratio based on the joint strength theory of structural loess is corrected. Then, the tangent deformational modulus is re-determined by the modified failure stress ratio. Finally, the tangent Poisson's ratio is modified by the modified tangent deformational modulus, and the Duncan-Chang nonlinear constitutive model based on the joint strength theory is established, which provides a new method for reasonable consideration of the tensile strength characteristics of structural loess in the study on the stability of structural loess slopes.
The Duncan-Chang nonlinear model based on the Mohr-Coulomb strength criterion can better reflect the shear strength characteristics of the soil, but it is not suitable to reflect the tensile strength characteristics of the soil. In order to reflect the tensile strength of the structural loess reasonably, firstly, the strength of soil is re-determined by introducing the joint strength criterion into the Duncan-Chang nonlinear constitutive model, and the failure stress ratio based on the joint strength theory of structural loess is corrected. Then, the tangent deformational modulus is re-determined by the modified failure stress ratio. Finally, the tangent Poisson's ratio is modified by the modified tangent deformational modulus, and the Duncan-Chang nonlinear constitutive model based on the joint strength theory is established, which provides a new method for reasonable consideration of the tensile strength characteristics of structural loess in the study on the stability of structural loess slopes.
引文
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[9]谢晓华,沈珠江.土石坝计算中非线形模型的改进[J].水利水运科学研究,1988(3):43-55.(XIE Xiao-hua,SHENZhu-jiang.Modification of nonlinear model in the stress-strain analysis of earth and rockfill dam[J].Hydro-science and Engineering,1988(3):43-55.(in Chinese))
[10]田堪良,王沛,张慧莉.考虑结构性的原状黄土应力-变关系的探讨[J].岩土力学,2013,34(7):1893-1898.(TIAN Kan-liang,WANG Pei,ZHANG Hui-li.Discussion on stress-strain relation of intact loess considering soil structure[J].Rock and Soil Mechanics,2013,34(7):1893-1898.(in Chinese))
[11]陈昌禄,邵生俊,马林.考虑黄土结构性的修正邓肯-张模型研究[J].西北农林科技大学学报(自然科学版),2011,39(11):223-228.(CHEN Chang-lu,SHAO Sheng-jun,MALin.Study on modified Duncan-Chang model considering loess structural[J].Journal of Northwest A&F University(Natural Science Edition),2011,39(11):223-228.(in Chinese))
[12]许萍,邵生俊,张喆,等.真三轴应力条件下修正邓肯-张模型的试验研究[J].岩土力学,2013,34(12):3359-3364.(XU Ping,SHAO Sheng-jun,ZHANG Zhe,et al.Experimental study of modified Duncan-Chang model under true triaxial stresses[J].Rock and Soil Mechanics,2013,34(12):3359-3364.(in Chinese))
[13]KONDNER R L.Hyperbolic stress-strain response:cnesive soils[J].Journal of the Soil Mechanics and Foundation Division,1963,89(1):115-144.
[14]李广信.高等土力学[M].2版.北京:清华大学出版社,2016.(LI Guang-xin.Advanced soil mhanics[M].2nd ed.Beijing:Tsinghua University Press,2016.(in Chinese))
[2]DUNCAN J M,CHANG C Y.Nonlinear analysis of stress and strain in soils[J].Journal of Soil Mechanics and Foundations Division,1996,96(5):1629-1653.
[3]罗刚,张建民.邓肯-张模型和沈珠江双屈服面模型的改进[J].岩土力学,2004,25(6):887-890.(LUO Gang,ZHANG Jian-min.Improvement of Duncan-Chang nonlinear model and Shen Zhujiang’s elastoplastic model for granular soils[J].Rock and Soil Mechanics,2004,25(6):887-890.(in Chinese))
[4]李荣建,刘军定,郑文,等.基于结构性黄土抗拉和抗剪特性的双线性强度及其应用[J].岩土工程学报,2013,35(增刊2):247-252.(LI Rong-jian,LIU Jun-ding,ZHENGWen,et al.A bilinear strength formula for structured loess based on tensile strength and shear strength and its application[J].Chinese Journal of Geotechnical Engineering,2013,35(S2):247-252.(in Chinese))
[5]LI Rong-jian,LIU Jun-ding,YAN Rui,et al.Characteristics of structural loess strength and preliminary framework for joint strength formula[J].Water Science and Engineering,2014,7(3):319-330.
[6]王立忠,赵志远.考虑土体结构性的修正邓肯-张模型[J].水利学报,2004(1):83-89.(Wang Li-zhong,Zhao Zhi-yuan.Non-linear elastic model considering soil structural damage[J].Journal of Hydraulic Engineering,2004(1):83-89.(in Chinese))
[7]冯卫星,常绍东.北京细砂土邓肯-张模型参数试验研究[J],岩石力学与工程学报,1999,18(3):327-330.(FENGWei-xing,CHANG Shao-dong.Experimental study on parameters of Duncan-Chang model for Beijing fine sandy soil[J].Chinese Joural of Rock Mechanics and Engineering,1999,18(3):327-330.(in Chinese))
[8]沈广军.邓肯-张E-?模型的改进[J].河海大学学报:自然科学版,2010,38(1):109-114.(SHEN Guang-jun.Improvement of Ducan-Chang E-?model[J].Journal of Hohai University:Natural Sciences,2010,38(1):109-114.(in Chinese))
[9]谢晓华,沈珠江.土石坝计算中非线形模型的改进[J].水利水运科学研究,1988(3):43-55.(XIE Xiao-hua,SHENZhu-jiang.Modification of nonlinear model in the stress-strain analysis of earth and rockfill dam[J].Hydro-science and Engineering,1988(3):43-55.(in Chinese))
[10]田堪良,王沛,张慧莉.考虑结构性的原状黄土应力-变关系的探讨[J].岩土力学,2013,34(7):1893-1898.(TIAN Kan-liang,WANG Pei,ZHANG Hui-li.Discussion on stress-strain relation of intact loess considering soil structure[J].Rock and Soil Mechanics,2013,34(7):1893-1898.(in Chinese))
[11]陈昌禄,邵生俊,马林.考虑黄土结构性的修正邓肯-张模型研究[J].西北农林科技大学学报(自然科学版),2011,39(11):223-228.(CHEN Chang-lu,SHAO Sheng-jun,MALin.Study on modified Duncan-Chang model considering loess structural[J].Journal of Northwest A&F University(Natural Science Edition),2011,39(11):223-228.(in Chinese))
[12]许萍,邵生俊,张喆,等.真三轴应力条件下修正邓肯-张模型的试验研究[J].岩土力学,2013,34(12):3359-3364.(XU Ping,SHAO Sheng-jun,ZHANG Zhe,et al.Experimental study of modified Duncan-Chang model under true triaxial stresses[J].Rock and Soil Mechanics,2013,34(12):3359-3364.(in Chinese))
[13]KONDNER R L.Hyperbolic stress-strain response:cnesive soils[J].Journal of the Soil Mechanics and Foundation Division,1963,89(1):115-144.
[14]李广信.高等土力学[M].2版.北京:清华大学出版社,2016.(LI Guang-xin.Advanced soil mhanics[M].2nd ed.Beijing:Tsinghua University Press,2016.(in Chinese))