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Bifurcation analysis of water-soil coupled overconsolidated clay
under plane strain condition |
| Department of Civil Engineering, Shanghai University, Shanghai 200072, China |
| Department of Civil Engineering, Shanghai University, Shanghai 200072, China |
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Abstract Based on the Hvorslev’s envelopebased threedimensional elastoplastic constitutive model for overconsolidated clay, an acoustic tensor of bifurcation for strain localization under undrained and drained conditions was obtained in the explicit form. The influences of permeability, drainage path length and strain rate on the bifurcation were analyzed. Theoretical results show that the strain localization bifurcation is related to the water seepage for watersoil twophase material. The numerical simulation of plane strain tests on a cubic specimen for the bifurcation under drained condition was conducted by using a nonlinear finite element analysis software ABAQUS with the model being implemented. Numerical results show that the greater the permeability, the sooner the bifurcation occurs when the drainage path length and the strain rate are fixed; when the permeability is fixed, the greater the drainage path length and the strain rate, the later the bifurcation occurs; the strain corresponding to the bifurcation is constant when the time factor is given.
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Published: 01 October 2010
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平面应变条件下水土耦合超固结黏土分叉分析
基于Hvorslev面超固结黏土三维弹塑性本构模型,导出在不排水和排水固结条件下饱和黏土的应变局部化分叉条件,分析不同渗透系数、排水路径长度和应变速率对分叉的影响.理论分析表明,在平面应变条件下,土体应变局部化分叉随着孔隙水的流动程度发生显著变化.利用嵌入上述本构模型的有限元软件ABAQUS,在平面应变应力路径下对加载面排水的多单元立方体应变局部化分叉现象进行数值分析.结果表明：当排水路径长度和应变速率一定时,渗透系数越大,应变局部化分叉出现得越早；当渗透系数一定时,排水路径长度和应变速率越大,应变局部化分叉出现得越晚；当时间因数一定时,应变局部化分叉出现时对应的剪应变一定.
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| ［1］ HILL R. A general theory of uniqueness and stability in elasticplastic solids ［J］. Journal of the Mechanics and Physics of Solids, 1958, 6 (3): 236-249.
［2］ RICE J R. The localization of plastic deformation ［C］∥ Theoretical and Applied Mechanics. Amsterdam: NorthHolland, 1976: 207220.［3］ OTTOSEN N S, RUNESSON K. Properties of discontinuous bifurcation solutions in elastoplasticity ［J］. International Journal of Solids and Structures, 1991, 27(4): 231-254.
［4］ 张洪武.饱和多孔介质分析解的唯一性与应变局部化分岔［J］.力学学报,2000,32(6): 686-697.
ZHANG Hongwu. Uniqueness and localization bifurcation analysis solution of saturated porous media ［J］. Acta Mechanica Sinica, 2000, 32(6): 686-697.
［5］ ZHANG H W, SCHREFER B A. Uniqueness and localization analysis of elasticplastic saturated porous media［J］. International Journal for Numerical and Analytical Methods in Geomechanics, 2001, 25(1): 29-48.
［6］ 徐连民,朱合华,中井照夫,等.超固结粘土的剪切带数值模拟［J］.岩土力学,2006,27(1): 61-66.
XU Lianmin, ZHU Hehua, NAKAI Teruo, et al. Numerical simulation of shear band in overconsolidated clay ［J］. Rock and Soil Mechanics, 2006, 27(1): 61-66.
［7］ 姚仰平,李自强,侯伟,等.基于改进伏斯列夫线的超固结土本构模型［J］.水利学报,2008,39(11): 1244-1250.
YAO Yangping, LI Ziqiang, HOU Wei, et al. Constitutive model of overconsolidated clay based on improved Hvorslev envelope ［J］. Journal of Hydraulic Engineering, 2008, 39(11): 1244-1250.
［8］ YAO Y P, HOU W, ZHOU A N. UH model: threedimensional unified hardening model for overconsolidated clays ［J］. Geotechnique, 2009, 59(5): 451-469.
［9］ 孙德安,甄文战.不同应力路径下剪切带的数值模拟［J］.岩土力学,2010,31(7): 2253-2258.
SUN Dean, ZHEN Wenzhan. Numerical simulation of shear bands along different stress paths ［J］. Rock and Soil Mechanics, 2010, 31(7): 2253-2258.
［10］ RUDNICKI J W, RICE J R. Conditions for the localization of deformation in pressuresensitive dilatant materials ［J］. Journal of the Mechanics and Physics of Solids, 1975, 23(6): 371-394. |
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