CREEP BEHAVIOR OF ZHANJIANG STRONG STRUCTURED CLAY BY DRAINED TRIAXIAL TEST
(1. State Key Laboratory of Geomechanics and Geotechnical Engineering，Institute of Rock and Soil Mechanics，Chinese Academy of Sciences，Wuhan，Hubei 430071，China；2. Fourth Harbour Engineering Investigation and Design Institute Co.，Ltd.，China Communications Construction Company，Guangzhou，Guangdong 510230，China)
Abstract：The drained triaxial shear creep tests for Zhanjiang strong structured clay under different confining pressures by GDS triaxial testing system are performed. The relationships of axial strain and volumetric strain with stress and time are obtained. The effect of soil structural property on its creep behavior is analyzed；and the corresponding creep model is established. The results show that the evolution characteristics of creep deformation of Zhanjiang clay are restricted by its poorly structural property；and its sensitivity is related to the structural property of soil. The creep deformation and deformation rate of Zhanjiang clay are small in the range of low deviatoric stress；when the deviatoric stress exceeds a critical value，the soil mass failure occurs in a short time. The overall behavior of volumetric strain of Zhanjiang clay in the process of drained triaxial shear creep presents shear contraction，while a certain shear contraction and shear dilation alternately appear during the creep time under the condition of ?3＜?k，i.e. there exists rebound phenomenon；and it presents shear contraction when ?3≥?k. The strength attenuation induced by creep mainly results in cohesion reduction，and 77.63%. It is found that the six-element extended Burgers model could effectively describe the three deformation stages of the instantaneous elastic strain，attenuation creep and stable creep for Zhanjiang clay. In actual project，the soil structural property should be clearly understood；the favorable factors of structural property of soil could be used in low stress level；but the designed load is forbidden to exceed the structural yield stress.
谭罗荣，张梅英. 一种特殊土的微观结构特性的研究[J]. 岩土工程学报，1982，4(2)：26-35.(TAN Luorong，ZHANG Meiying. The research on microscopic structure properties of a particular soil[J]. Chinese Journal of Geotechnical Engineering，1982，4(2)：26-35.(in Chinese))
[4]
孔令伟，吕海波，汪 稔，等. 海口某海域软土工程特性的微观机制浅析[J]. 岩土力学，2002，23(1)：36-40.(KONG Lingwei，LU Haibo，WANG Ren，et al. Preliminary analysis of micro-mechanism of engineering properties for soft soil in a sea area of Haikou[J]. Rock and Soil Mechanics，2002，23(1)：36-40.(in Chinese))
<body>Your browse does not support frame!</body> " target="_blank">
[6]
沈珠江. 土体结构性的数学模型——21世纪土力学的核心问题[J]. 岩土工程学报，1996，18(1)：95-97.(SHEN Zhujiang. Mathematical model of soil structural property kernel problem of soil mechanics in 21st century[J]. Chinese Journal of Geotechnical Engineering，1996，18(1)：95-97.(in Chinese))
朱鸿鹄，陈晓平，程小俊，等. 考虑排水条件的软土蠕变特性及模型研究[J]. 岩土力学，2006，27(5)：694-698.(ZHU Honghu，CHEN Xiaoping，CHENG Xiaojun，et al. Study on creep characteristics and model of soft soil considering drainage condition[J]. Rock and Soil Mechanics，2006，27(5)：694-698.(in Chinese))
<body>Your browse does not support frame!</body> " target="_blank">
张先伟，王常明，王钢城，等. 黄石淤泥质土的剪切蠕变特性及模型研究[J]. 吉林大学学报(地球科学版)，2009，39(1)：119-125. (ZHANG Xianwei，WANG Changming，WANG Gangcheng，et al. Study on shearing creep characteristics and constitutive model of Huangshi mucky soil[J]. Journal of Jilin University(Earth Science)，2009，39(1)：119-125.(in Chinese))
[1]
拓勇飞，孔令伟，郭爱国，等. 湛江地区结构性软土的赋存规律及其工程特性[J]. 岩土力学，2004，25(12)：1 879-1 884.(TUO Yongfei，KONG Lingwei，GUO Aiguo，et al. Occurrence and engineering properties of structural soft clay in Zhanjiang area[J]. Rock and Soil Mechanics，2004，25(12)：1 879-1 884.(in Chinese))
<body>Your browse does not support frame!</body> " target="_blank">
[13]
龚晓南，熊传祥，项可祥，等. 黏土结构性对其力学性质的影响及形成原因分析[J]. 水利学报，2000，22(10)：43-47.(GONG Xiaonan，XIONG Chuanxiang，XIANG Kexiang，et al. The formation of clay structure and its influence on mechanical characteristics of clay[J]. Journal of Hydraulic Engineering，2000，22(10)：43-47.(in Chinese))
<body>Your browse does not support frame!</body> " target="_blank">
[3]
孔令伟，吕海波，汪 稔，等. 湛江海域结构性海洋土的工程特性及其微观机制[J]. 水利学报，2002，(9)：82-88.(KONG Lingwei，LU Haibo，WANG Ren，et al. Engineering properties and micro- mechanism of a structural marine soil in Zhanjiang sea area[J]. Journal of Hydraulic Engineering，2002，(9)：82-88.(in Chinese))
<body>Your browse does not support frame!</body> " target="_blank">
[5]
拓勇飞. 湛江软土结构性的力学效应与微观机制研究[硕士学位论文][D]. 武汉：中国科学院武汉岩土力学研究所，2004.(TUO Yongfei. Research on mechanics effect and micro-mechanism of structural soft clay in Zhanjiang area[M. S. Thesis][D]. Wuhan：Institute of Rock and Soil Mechanics，Chinese Academy of Sciences，2004.(in Chinese))
<body>Your browse does not support frame!</body> " target="_blank">
蔡 羽，孔令伟，郭爱国，等. 剪应变率对湛江强结构性黏土力学性状的影响[J]. 岩土力学，2006，27(8)：1 235-1 240.(CAI Yu，KONG Lingwei，GUO Aiguo，et al. Effects of shear strain rate on mechanical behavior of Zhanjiang strong structured clay[J]. Rock and Soil Mechanics，2006，27(8)：1 235-1 240.(in Chinese))
<body>Your browse does not support frame!</body> " target="_blank">
[9]
张先伟，王常明，李军霞，等. 蠕变条件下软土微观孔隙变化特性[J]. 岩土力学，2010，31(4)：1 060-1 067.(ZHANG Xianwei，WANG Changming，LI Junxia，et al. Variation characteristics of soft clay micropore in the creep condition[J]. Rock and Soil Mechanics，2010，31(4)：1 060-1 067.(in Chinese))
<body>Your browse does not support frame!</body> " target="_blank">
[11]
汤 斌. 软土固结蠕变耦合特性的试验研究与理论分析[博士学位论文][D]. 武汉：武汉大学，2004.(TANG Bin. Study on tests and analysis of theory of coupled behaviors of consolidation and creep of soft clay[Ph. D. Thesis][D]. Wuhan：Wuhan University，2004.(in Chinese))
<body>Your browse does not support frame!</body> " target="_blank">
2011, Vol. 30 
