Modified Duncan-Chang Model and Mechanics Parameter Determination Based on Triaxial Consolidated Drained Tests of Guiyang Red Clay in China
A large area of China Southwest is covered by red clay, which is a kind of Karst regional special clay with high moisture content, high ductility, large void ratio, low density, poor compaction. Based on Duncan-Chang model, the constitutive model of red clay and its mechanical parameters are studied by laboratory tests and numerical simulation. (1) According to the results of triaxial consolidated drained tests with different moisture content, the damage forms, stress-strain curve, the relationships between pore water pressure and displacement changing with the time are analyzed in detail. (2) Based on Duncan-Chang model, the incremental elastic curve is fitted. The curve is composed of three segments which represent the deformation law of the clay samples in compression-shearing process. Correspondingly, the initial tangent elastic modulus is modified into a three-stage function, and the Duncan-Chang model of Guiyang red clay is obtained and the parameters such as shear strength, failure ratio, tangent Poisson’s ratio and tangent volume modulus are calculated. (3) VC++ programming language is used to modify Duncan-Chang E-B model in the software of FLAC3D. The results show that the numerical simulation curve is in good agreement with the stress-strain curve of the experiments, which shows that the modified Duncan-Chang model has good feasibility and applicability to Guiyang red clay.
This work is supported by the National Natural Science Foundation of China (51469007), Guizhou Science and Technology Support Project for Social development (3055), Science and technology research and development project of CSCEC(CSCEC4B-2015-KT-03). They are gratefully acknowledged.
- Liao, Y., Zhu, L.: The red clay of Guizhou carbonate rock. Guizhou People Press, Guiyang (2004)Google Scholar
- Shen, Z.: Mathematical model of soil structure. J. Geotech. Eng. 18(1), 95–97 (1996)Google Scholar
- Zhang, Y., Deng, A.: Proof test for constitutive model of Chongqing’s Laterite. J. Chongqing Jianzhu Univ. 19(2), 48–53 (1997)Google Scholar
- Liu, D.: Research on Calculation and Prediction Method of Red Clay Foundation Settlement in Wuhan-Guangzhou Passenger Dedicated Line. Central South University (2009)Google Scholar
- Chen, K., Xing, H.: Reserach on deformation characteristics of high liquid limit red clay. J. Highw. Transp. Res. Dev. 23(3), 49–54 (2010)Google Scholar
- Zhou, Y., Liu, X., Yu, Y., et al.: Lateral unloading true triaxial test and analysis of mechanical properties for red clay. J. Chongqing Univ. 37(6), 18–24 (2014)Google Scholar
- Fang, W.: Research on Stability Analysis Method of Cutting Slope of Residual Red Clay. Central South University (2011)Google Scholar
- Geotechnical Test Procedures (1999) China Water Conservancy and Hydropower Press, BeijingGoogle Scholar
- He, L., Kong, L.: Uniform expression of stress-strain relationship of soils. J. Eng. Geol. 18(6), 900–905 (2010)Google Scholar
- Wang, L., Zhao, Z., Li, L.: Modified Dunean-Chang model considering soil strueture. J. Hydraul. Eng. 1, 83–89 (2004)Google Scholar
- Chen, Z.: Principle, Method and Procedure of Soil Slope Stability Analysis. China Water Conservancy and Hydropower Press, Beijing (2003)Google Scholar