不同三维应力路径下超固结黏土变形局部化
孙德安, 陈立文, 甄文战
上海大学土木工程系,上海 2100720
Strain localization of overconsolidated clay under different three-dimensional stress paths
SUN De-an, CHEN Li-wen, ZHEN Wen-zhan
Department of Civil Engineering, Shanghai University, Shanghai 200072, China
摘要 利用非线性有限元软件 ABAQUS 材料子程序接口,采用回映应力更新算法,实现了基于改进伏斯列夫面超固结黏土三维本构模型在有限元分析中的应用。通过该模型与比奥固结理论的耦合,对超固结比为 8 的藤森黏土在三轴压缩、三轴伸长及平面应变时的变形局部化问题,进行了三维应力状态下的土水耦合弹塑性分析。分析结果表明:剪切带带内、带外点经历了大致 相同 的应力路径;剪切带带外单元体变经历了体缩,而剪切带带内单元一直保持剪胀趋势;剪切带的形成伴随着剪胀,剪切带内外出现了负的孔压,且孔压的分布也具有局部化特性。关于剪切带带内、带外的孔隙水压及体积变化趋势,平面应变介于三轴压缩与三轴伸长之间,但平面应变较早出现剪切带。
关键词 :
超固结黏土 ,
孔压 ,
剪胀 ,
三维应力 ,
剪切带
Abstract :An improved Hvorslev envelope-based three-dimensional elastoplastic constitutive model was proposed by Yao et al. (2008) for overconsolidated clays. The return mapping algorithm is adopted in order to implement the constitutive model into a finite element analysis software ABAQUS through the user material subroutine interface. By coupling the model with the Biot’s consolidation theory, coupled analyses of the localized deformation on overconsolidated clay specimens under undrained boundary conditions in triaxial compression and extension and plane strain stress states are performed. The numerical results show that the same stress paths are seen for the elements inside and outside the shear band. The elements in the vicinities of the shear band behave volume contracted, while the elements inside the shear band keep shear dilatancy during shear. The shear dilatancy is accompanied by the development of the shear band, and negative pore pressure appears inside the shear band and their vicinities. The changes in the pore water pressure and volumetric strain in the plane strain are between triaxial compression and extension stresses, but shear bands early occur in the plane strain.
Key words :
overconsolidated clay
pore pressure
dilatancy
three-dimensional stress
shear band
收稿日期: 2011-04-29
作者简介 : 孙德安 (1962 – ) ,男,浙江余姚人,博士,教授,博士生导师,主要从事非饱和土力学、土的基本性质及其本构理论等方面的研究与教学工作。
[1] 李 蓓 , 赵锡宏 , 董建国 . 上海黏土剪切带倾角的试验研究 [J]. 岩土力学 , 2002, 23 (4): 423 – 427. (LI Bei, ZHAO Xi-hong, DONG Jian-guo. Experimental study on shear band inclination in Shanghai clay[J]. Rock and Soil Mechanics, 2002, 23 (4): 423 – 427. (in Chinese)) [2] WANG Q, LADE P V. Shear banding in true triaxial tests and its effect on failure in sand[J]. Journal of Engineering Mechanics, ASCE, 2001, 127 (8): 754 – 761. [3] 钱建固 , 黄茂松 . 土体变形分叉的非共轴理论 [J]. 岩土工程学报 , 2004, 26 (6): 777 – 781. (QIAN Jian-gu, HUANG Mao-song. Non-coaxiality for deformation bifurcation in soils[J]. Chinese Journal of Geotechnical Engineering, 2007, 26 (2): 465 – 471. (in Chinese)) [4] 甄文战 , 孙德安 , 段 博 . 超固结土本构模型分叉三维理论分析及数值模拟 [J]. 岩土工程学报 , 2010, 32 (12): 1921 – 1926. (ZHEN Wen-zhan, SUN De-an, DUAN Bo. Theoretical analysis and numerical simulation of three-dimensional bifurcation by constitutive model for over-consolidated clays [J]. Chinese Journal of Geotechnical Engineering, 2010, 32 (12): 1921 – 1926. (in Chinese)) [5] HUANG W X, SUN D A, SLOAN S W. Analysis of the failure mode and softening behaviour of sands in true triaxial tests[J]. International Journal of Solids and Structures, 2007, 44 (5): 1423 – 1437. [6] 蔡正银 . 砂土的渐进破坏及其数值模拟 [J]. 岩土力学 , 2008, 29 (3): 580 – 585. (CAI Zheng-yin. Progressive failure of sand and its numerical simulation[J]. Rock and Soil Mechanics, 2008, 29 (3): 580 – 585. (in Chinese)) [7] 徐连民 , 王兴然 . 用有限变形理论研究黏性土试样中变形的局部化问题 [J]. 岩土工程学报 , 2004, 26 (2): 125 – 129. (XU Lian-min, WANG Xing-ran. Numerical simulation of shear band in clayey soils using finite deformation theory[J]. Chinese Journal of Geotechnical Engineering, 2004, 26 (2): 125 – 129. (in Chinese)) [8] 甄文战 , 孙德安 , 段 博 . 不同应力路径下超固结黏土试样变形局部化分析 [J]. 岩土力学 , 2011, 32 (1): 293 – 298. (ZHEN Wen-zhan, SUN De-an, DUAN Bo. Analysis of strain localization in overconsolidated clay specimens along different stress paths[J]. Rock and Soil Mechanics, 2011, 32 (1): 293 – 298. (in Chinese)) [9] 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 Yang-ping, LI Zi-qiang, HOU Wei, et al. Constitutive model of over-consolidated clay based on improved Hvorslev envelope[J]. Journal of Hydraulic Engineering, 2008, 39 (11): 1244 – 1250. (in Chinese)) [10] YAO Y P, HOU W, ZHOU A N. UH model: three-dimensional unified hardening model for overconsolidated clays[J]. Géotechnique, 2009, 59 (5): 451 – 469. [11] 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 De-an, ZHEN Wen-zhen. Numerical simulation of shear bands along different stress paths[J]. Rock and Soil Mechanics, 2010, 31 (7): 2253 – 2258. (in Chinese) )
[1]
邓建, 肖明, 谢冰冰, 陈俊涛. 循环荷载下岩体结构面本构关系与积分算法研究 [J]. 岩土工程学报, 2017, 39(6): 1048-1057.
[2]
刘斯宏, 邵东琛, 沈超敏, 王子健. 一个基于细观结构的粗粒料弹塑性本构模型 [J]. 岩土工程学报, 2017, 39(5): 777-783.
[3]
王翔鹰, 刘汉龙, 江强, 陈育民. 抗液化排水刚性桩沉桩过程中的孔压响应 [J]. 岩土工程学报, 2017, 39(4): 645-651.
[4]
郭楠, 陈正汉, 高登辉, 周勇, 杨校辉, 扈胜霞. 加卸载条件下吸力对黄土变形特性影响的试验研究 [J]. 岩土工程学报, 2017, 39(4): 735-742.
[5]
陈艳妮, 杨仲轩. 基于热力学理论的超固结黏土边界面模型 [J]. 岩土工程学报, 2017, 39(3): 547-553.
[6]
李镜培, 李林, 孙德安, 龚卫兵. 基于CPTU测试的K 0 固结黏土中静压桩时变承载力研究 [J]. 岩土工程学报, 2017, 39(2): 193-200.
[7]
闫澍旺, 张京京, 陶琳, 孙立强. 等向固结饱和黏土卸载特性影响因素研究 [J]. 岩土工程学报, 2016, 38(z2): 42-47.
[8]
郭莹, 韩杰. 成样方法及应力路径对饱和中密细砂CU剪切特性影响 [J]. 岩土工程学报, 2016, 38(z2): 79-84.
[9]
王刚, 张建民, 魏星. 地层条件对剪胀性砂土边坡地震后延迟变形的影响 [J]. 岩土工程学报, 2016, 38(7): 1345-1350.
[10]
曹振中, 刘荟达, 袁晓铭. 砾性土液化特性与机理 [J]. 岩土工程学报, 2016, 38(7): 1165-1174.
[11]
赵毅, 周小平, 钱七虎. 基于广义粒子动力学的巷道围岩弹塑性分析 [J]. 岩土工程学报, 2016, 38(6): 1104-1116.
[12]
王学滨, 张楠, 潘一山, 杜亚志. 单轴压缩湿土样最大剪切应变场数字图像相关方法结果的统计分析 [J]. 岩土工程学报, 2016, 38(6): 996-1003.
[13]
邵龙潭, 刘港, 郭晓霞. 三轴试样破坏后应变局部化影响的实验研究 [J]. 岩土工程学报, 2016, 38(3): 385-394.
[14]
蒋基安, 陈海英, 陈越, 叶佳雯. 排水板真空度损耗的排水固结解析解 [J]. 岩土工程学报, 2016, 38(3): 404-418.
[15]
周正龙, 陈国兴, 吴琪. 初始剪应力对饱和粉土液化特性影响试验研究 [J]. 岩土工程学报, 2016, 38(3): 504-509.