湛江强结构性黏土的三轴排水蠕变特征

摘要
图/表
参考文献
相关文章 (15)

全文: PDF (507 KB) HTML (1 KB)
输出: BibTeX | EndNote (RIS)

摘要利用GDS应力路径三轴试验系统，开展不同围压下湛江强结构性黏土的三轴固结排水剪切蠕变试验，获得其轴向应变、体应变与应力和时间的关系，分析蠕变性状的结构性效应，建立相应的蠕变模型。结果表明，湛江黏土的蠕变变形演化特征受其强结构性制约，其蠕变特性的敏感程度与结构性强弱相关联。在低偏应力下，其蠕变变形和变形速率均较小；偏应力超过临界值后，土体在短时间内发生破坏。湛江黏土在?3＜?k时，其体变性状总体上表现为剪缩，但随时间变化出现一定的剪缩和剪胀交替性，即存在回弹现象；而当?3≥?k时，则表现为剪缩。蠕变引起的强度衰减主要表现为黏聚力的降低，且 77.63%。采用6元件扩展Burgers模型能较好地描述湛江黏土的瞬时弹性应变、衰减蠕变和稳定蠕变3个阶段。在实际工程中，必须对土的结构性给予充分的认识，在较低应力范围内，可以利用其结构性的有利因素，但设计荷载严禁超出结构屈服应力。

	服务

	把本文推荐给朋友
	加入我的书架
	加入引用管理器
	E-mail Alert
	RSS
	作者相关文章

关键词 ：土力学, 湛江黏土, 强结构性, 三轴排水剪切蠕变试验, 扩展Burgers模型

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.

Key words： soil mechanics Zhanjiang clay strong structural property drained triaxial shear creep test extended Burgers model

收稿日期: 2010-09-07

引用本文:

孔令伟1，张先伟1，郭爱国1，蔡羽1，2. 湛江强结构性黏土的三轴排水蠕变特征[J]. 岩石力学与工程学报, 2011, 30(2): 365-372.
KONG Lingwei1，ZHANG Xianwei1，GUO Aiguo1，CAI Yu1，2. CREEP BEHAVIOR OF ZHANJIANG STRONG STRUCTURED CLAY BY DRAINED TRIAXIAL TEST. , 2011, 30(2): 365-372.

链接本文:

http://www.rockmech.org/CN/Y2011/V30/I2/365

[2]	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)) " 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))
[8]	PUSCH R，ZHANG L，ADEY R，et al. Rheology of an artificial smectitic clay[J]. Applied Clay Science，2010，47(1-2)：120-126. " target="_blank">
[10]	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)) " target="_blank">
[12]	张先伟. 结构性软土蠕变特性及扰动状态模型[博士学位论文][D]. 长春：吉林大学，2010.(ZHANG Xianwei. Creep characteristics of structured soft clay and its DSC model[Ph. D. Thesis][D]. Changchun：Jilin University，2010.(in Chinese)) " target="_blank">
[16]	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)) " 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)) " 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)) " 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)) " target="_blank">
[7]	SOGA K，MITCHELL J K. Rate-dependent deformation of structured natural clays[C]// Geotechnical Measuring and Modeling Time Dependent Soil Behavior. New York：[s.n.]，1996：243-257. " target="_blank">
[15]	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)) " 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)) " 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)) " target="_blank">
[14]	MESRI G，ROSKHSAR A，BOHOR B F. Composition and compressibility of typical samples of Mexico City clay[J]. Geotechnique，1995，25(3)：527-554. " target="_blank">