关键词: 单轴蠕变试验, 页岩, 含水率, 层理, 蠕变模型

Abstract: In order to analyze the influence of bedding and water on the creep characteristics of shale, five kinds of shale are prepared in the laboratory, including 0, 30, 60, 90 degrees and no bedding. Each kind of bedding shale is treated with 4 kinds of water bearing state, which is dry, natural, water unsaturated and water saturated. The results show that: (1) The bedding angle and water content have great influence on the creep characteristics of shale. At the same moisture content, with the increase of the angle of stratification, the initial instantaneous elasticity of shale decreases exponentially and the instantaneous elastic modulus increases exponentially. At the same layer angle, with the increase of moisture content, the initial instantaneous elastic strain linear growth of shale and linear decrease of instantaneous elastic modulus. (2) The creep of shale is described by Burgers creep model with elastic elements, viscous elements and Kelvin body, and the parameters of the model inversion and the verification. The results show that the model can better reflect the features of the shale creep. According to the law of the influence of the bedding and water on the creep deformation of shale and based on the fitting relationship between the instantaneous elastic modulus, the viscosity coefficient and the bedding angle, water content, the instantaneous elastic modulus and viscosity coefficient of the creep model are replaced by a function of the bedding angle and moisture content; thus a creep model which can reflect shale bedding and water content is constructed.

Key words: uniaxial creep test, shale, moisture content, bedding, creep model