摘要
黏弹性组合模型由于其概念简单,在岩土工程领域已经得到广泛的应用。这类模型及其参数通常是由一维蠕变试验得到,再根据一些常用假设,如常泊松比假设、常体积模量假设等,被应用于三维工程。但由于模型的参数在蠕变试验与工程应用时选取往往不同,而参数的变换关系通常并没有被明确提出,特别是黏性参数也需相应地发生变化的这一事实,则经常被忽视。根据上述两种常用假设下的三维蠕变方程,利用一维蠕变应力特点,间接得到一维蠕变方程,从理论上明确地体现出这两种假设下材料的不同蠕变方程。在此基础上,建议黏弹组合模型参数的确定方法。然后,采用岩土工程领域中广泛使用的广义Kelvin模型来进行说明,对比不考虑任何假设的常规方式下的参数选取,给出该模型在两种不同假设情况下的变换关系。最后,通过算例验证该变换关系。
The viscoelastic model, which consists of spring and dashpot, has been widely used in geotechnical engineering as it has explicit physical and mechanical meaning. Generally, the model and its parameters obtained from creep test in one-dimension, are applied to the model in three-dimensional geotechnical engineering based on a few hypotheses, such as constant Poisson＇s ratio, constant volumetric modulus and so on. While parameters of the viscoelastic model are differently used in creep test and in geotechnical engineering, and their conversion relations are not definitely presented in the predecessor＇s studies. Especially, the fact that viscous parameters should be changed accordingly is often ignored. In this paper, the creep equations in one-dimension with the above hypotheses are indirectly obtained from the equations in three-dimensions. The conclusion that the creep equations are different with different hypotheses in one-dimension is drawn. Then, the method to determinate parameters of the viscoelastic model is suggested. As an example, the generalized Kelvin creep equations with the hypotheses are solved with the proposed methods and contrasted with the common creep equation without hypothesis. The conversion relations of model parameters under different hypotheses are presented and validated by a geotechnical engineering instance.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2007年第6期1226-1231,共6页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(50325414
50539090)
国家重点基础研究发展规划(973)项目(2002CB412708)
关键词
岩石力学
蠕变试验
常泊松比
常体积模量
黏弹模型
参数测定
rock mechanics
creep test
constant Poisson＇s ratio
constant volumetric modulus
viscoelastic model
parameters determination
