黏土水泥浆流变本构模型及其时变特性研究

Study on Rheological Constitutive Model and Time-varying Characteristics of Clay Cement Slurry

黏土水泥浆具有可注性好、性能优良等特点,但现有注浆压力、扩散半径等参数的确定方法已无法满足工程实际的需要,有必要深入系统地研究黏土水泥浆的流变本构模型及其时变特性以指导注浆参数的合理选择。通过设计室内试验探究了黏土水泥浆的本构模型及其时变特性影响,并通过理论分析构建考虑本构时变特性的黏土水泥浆裂隙扩散方程。主要研究结论如下:①黏土水泥浆符合宾汉流型,且随连续流动时间的延长能够保持宾汉流型不变;②黏土水泥浆的屈服应力和塑性黏度随流动时间呈幂指数增长模式;③以宾汉流型为基础构建了黏土水泥浆时变本构方程及考虑时变特性影响的裂隙层流扩散方程。

Clay cement slurry has the characteristics of good injectability and excellent performance.However,the existing methods for determining parameters such as grouting pressure and diffusion radius cannot meet the needs of engineering reality.It is necessary to study the rheological constitutive model and time-varying characteristics of clay cement slurry in depth and systematically to guide the reasonable selection of grouting parameters.The constitutive model of clay cement slurry and its time-varying characteristics are explored by designing laboratory tests,and the fracture diffusion equation of clay cement slurry considering the time-varying characteristics of constitutive model is constructed by theoretical analysis.The main conclusions are as follows:①The clay cement slurry conforms to the Bingham flow pattern and can maintain the Bingham flow pattern with the extension of continuous flow time.②The yield stress and plastic viscosity of clay cement slurry increase exponentially with flow time.③Based on the Bingham flow pattern,the time-dependent behavior equation of clay cement slurry and the laminar flow diffusion equation considering the time-varying characteristics are constructed.