黏性土一维松弛及其与次压缩的关系
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摘要
国内外学者对一维松弛规律进行了丰富的研究,但推导过程较为复杂。基于Buisman次压缩方程,结合Bjerrum提出的等时间压缩线的概念,采用一个简单的方法推导得出了双对数形式和单对数形式的一维应力松弛公式。给出了这两种形式的应力松弛关系曲线的斜率与参数c_a/c_c之间的关系,其中c_a为次压缩指数,c_c为压缩指数。并采用上海黏土进行了一维次压缩和松弛试验,验证了这两种形式的应力松弛关系的可靠性。最后还根据Mesri and Godlewski给出的c_a/c_c的范围,预估了一般黏性土的一维应力松弛速率。
The behaviors of one-dimensional relaxation have been studied by many researchers. However, the method for deducing the stress relax formulas is usually complic_ated. Two simple stress relaxation formulas in single-logarithmic form and double-logarithmic form are derived, which are based on the Buisman secondary compression equation and the concept of the equal-time compression line proposed by Bjerrum. The relationships between the slopes of these two types of stress relaxation formulas and the parameter c_a/c_c are proposed, here c_a is the secondary compression index and c_c is the compression index.One-dimensional secondary compression and the stress relaxation tests using Shanghai clay are conducted. The reliability of the stress relaxation formulas is verified. Moreover, the one-dimensional stress relaxing rate of general cohesive soils is estimated ac_cording to the values of c_a/c_c proposed by Mesri and Godlewski.
The behaviors of one-dimensional relaxation have been studied by many researchers. However, the method for deducing the stress relax formulas is usually complic_ated. Two simple stress relaxation formulas in single-logarithmic form and double-logarithmic form are derived, which are based on the Buisman secondary compression equation and the concept of the equal-time compression line proposed by Bjerrum. The relationships between the slopes of these two types of stress relaxation formulas and the parameter c_a/c_c are proposed, here c_a is the secondary compression index and c_c is the compression index.One-dimensional secondary compression and the stress relaxation tests using Shanghai clay are conducted. The reliability of the stress relaxation formulas is verified. Moreover, the one-dimensional stress relaxing rate of general cohesive soils is estimated ac_cording to the values of c_a/c_c proposed by Mesri and Godlewski.
引文
[1]ALEXANDRE G,MARTINS I.Stress relaxation under various stress and drainage conditions[J].Archive Ouverte HAL,2012:1-54.
[2]MARTINS I S M.Fundamentals of a behavioral model for saturated clayey soils[D].Rio de Janeiro:COPPE/UFRJ,1992.
[3]TONG F,YIN J H.Experimental and constitutive modeling of relaxation behaviors of three clayey soils[J].Journal of Geotechnical and Geoenvironmental Engineering,2013,139(11):1973-1981.
[4]朱启银.软黏土的流变特性及流变参数统一性研究[D].上海:上海交通大学,2014.(ZHU Qi-yin.Time-dependent behavior and uniqueness of its key parameters for soft clays[D].Shanghai:Shanghai Jiao Tong University,2014.(in Chinese))
[5]KUTTER B L,SATHIALINGAM N.Elastic-viscoplastic modelling of the rate-dependent behavior of clays[J].Géotechnique,1992,42(3):427-441.
[6]VERMEER P A,STOLLE D F A,BONNIER P G.From the classical theory of secondary compression to modern creep analysis[C]//Proceedings of the 9th International Conference on Computer Methods and Advances in Geomechanics.Wuhan,1997:2469-2478.
[7]YIN Z Y,ZHU Q Y,YIN J H,et al.Stress relaxation coefficient and formulation for soft soils[J].Géotechnique Letters,2014,4(1):45-51.
[8]BJERRUM L.Engineering geology of Norwegian normally-consolidated marine clays as related to settlements of buildings[J].Géotechnique,1967,17(2):83-118.
[2]MARTINS I S M.Fundamentals of a behavioral model for saturated clayey soils[D].Rio de Janeiro:COPPE/UFRJ,1992.
[3]TONG F,YIN J H.Experimental and constitutive modeling of relaxation behaviors of three clayey soils[J].Journal of Geotechnical and Geoenvironmental Engineering,2013,139(11):1973-1981.
[4]朱启银.软黏土的流变特性及流变参数统一性研究[D].上海:上海交通大学,2014.(ZHU Qi-yin.Time-dependent behavior and uniqueness of its key parameters for soft clays[D].Shanghai:Shanghai Jiao Tong University,2014.(in Chinese))
[5]KUTTER B L,SATHIALINGAM N.Elastic-viscoplastic modelling of the rate-dependent behavior of clays[J].Géotechnique,1992,42(3):427-441.
[6]VERMEER P A,STOLLE D F A,BONNIER P G.From the classical theory of secondary compression to modern creep analysis[C]//Proceedings of the 9th International Conference on Computer Methods and Advances in Geomechanics.Wuhan,1997:2469-2478.
[7]YIN Z Y,ZHU Q Y,YIN J H,et al.Stress relaxation coefficient and formulation for soft soils[J].Géotechnique Letters,2014,4(1):45-51.
[8]BJERRUM L.Engineering geology of Norwegian normally-consolidated marine clays as related to settlements of buildings[J].Géotechnique,1967,17(2):83-118.