非饱和花岗岩残积土抗剪强度预测公式适用性研究
|
摘要
花岗岩残积土在我国华南地区分布极为广泛,通常处于非饱和状态,但国内外学者对非饱和花岗岩残积土的力学特性研究却较为有限。采用非饱和花岗岩残积土的不排水直剪试验数据对三个非饱和土强度预测公式进行了验证。结果表明Oberg公式所预测的强度与实测强度吻合度最高,同时该公式仅需提供土样破坏时的饱和度即可对强度进行预测,参数获取简单且便于工程推广。
The granitic residual soils are widely distributed in southern China and these soils are generally unsaturated in nature.However,the mechanical properties of the unsaturated granitic residual soils are rarely reported.This paper presents the undrained directed shear test result of the unsaturated granitic residual soils.The tested shear strength values were compared with three different formulas for the shear strength estimations.The comparative results indicate that the Oberg formula had the best estimation results.Further,this formula can predict the shear strength by only providing the degree of saturation at failure,therefore,it can be easily applied in the practical engineering projects.
The granitic residual soils are widely distributed in southern China and these soils are generally unsaturated in nature.However,the mechanical properties of the unsaturated granitic residual soils are rarely reported.This paper presents the undrained directed shear test result of the unsaturated granitic residual soils.The tested shear strength values were compared with three different formulas for the shear strength estimations.The comparative results indicate that the Oberg formula had the best estimation results.Further,this formula can predict the shear strength by only providing the degree of saturation at failure,therefore,it can be easily applied in the practical engineering projects.
引文
[1]凌华,殷宗泽,蔡正银.非饱和土的应力-含水率-应变关系试验研究[J].岩土力学,2008,29(3):651-655.
[2]Tekinsoy M A,Kayadelen C,Keskin M S,et al.An equation for predicting shear strength envelope with respect to matric suction[J].Computers and Geotechnics,2004,31(7):589-593.
[3]Lamborn M J.A Micromechanical Approach to Modeling Partly Saturated Soils[D].Texas:Texas A and M University,1986:67-75.
[4]Oberg A,Sallfors G.Determination of Shear Strength Parameters of Unsaturated Silts and Sands based on the Water Retention Curve[J].ASTM Geotechnical Testing Journal,1997,20(1):40-48.
[5]Rahardjo H.The Study of Undrained and Drained Behavior of Unsaturated Soils[D].Saskatoon:University of Saskatchewan,1990:306-315.
[6]栾茂田,李顺群,杨庆.非饱和土的基质吸力和张力吸力[J].岩土工程学报,2006,28(7):863-868.
[7]Tarantino A,Tombolato S.Coupling of Hydraulic and Mechanical Behaviour in Unsaturated Compacted Clay[J].Geotechnique,2005,55(4):307-317.
[8]Vanapalli S K,Fredlund D G,Pufahl D E,et al.Model for the Prediction of Shear Strength with respect to Soil Suction[J].Canadian Geotechnical Journal,1996,33(3):379-392.
[9]Fredlund D G,Xing A.Equations for the Soil-Water Characteristic Curve[J].Canadian Geotechnical Journal,1994,31(4):521-532.
[10]Guan G S,Rahardjo H,Choon L E.Shear Strength Equations for Unsaturated Soil under Drying and Wetting[J].Journal of Geotechnical and Geoenvironmental Engineering,2009,136(4):594-606.
[2]Tekinsoy M A,Kayadelen C,Keskin M S,et al.An equation for predicting shear strength envelope with respect to matric suction[J].Computers and Geotechnics,2004,31(7):589-593.
[3]Lamborn M J.A Micromechanical Approach to Modeling Partly Saturated Soils[D].Texas:Texas A and M University,1986:67-75.
[4]Oberg A,Sallfors G.Determination of Shear Strength Parameters of Unsaturated Silts and Sands based on the Water Retention Curve[J].ASTM Geotechnical Testing Journal,1997,20(1):40-48.
[5]Rahardjo H.The Study of Undrained and Drained Behavior of Unsaturated Soils[D].Saskatoon:University of Saskatchewan,1990:306-315.
[6]栾茂田,李顺群,杨庆.非饱和土的基质吸力和张力吸力[J].岩土工程学报,2006,28(7):863-868.
[7]Tarantino A,Tombolato S.Coupling of Hydraulic and Mechanical Behaviour in Unsaturated Compacted Clay[J].Geotechnique,2005,55(4):307-317.
[8]Vanapalli S K,Fredlund D G,Pufahl D E,et al.Model for the Prediction of Shear Strength with respect to Soil Suction[J].Canadian Geotechnical Journal,1996,33(3):379-392.
[9]Fredlund D G,Xing A.Equations for the Soil-Water Characteristic Curve[J].Canadian Geotechnical Journal,1994,31(4):521-532.
[10]Guan G S,Rahardjo H,Choon L E.Shear Strength Equations for Unsaturated Soil under Drying and Wetting[J].Journal of Geotechnical and Geoenvironmental Engineering,2009,136(4):594-606.