泥质砂岩蠕变特性与锚固控制效应试验研究

Experiment study of argillaceous sandstone creep characteristics and anchoring control effect

通过泥质砂岩单轴压缩蠕变试验,揭示岩石蠕变变形与破坏的特点,反映了不同应力路径下的岩石蠕变速率与发展过程,建立了泥质砂岩的非线性蠕变模型,并通过对试件施加侧向刚性约束和锚固约束,以反映地下工程围岩在平面应变状态和支护状态下的蠕变特性。研究结果表明,锚固约束可以显著提高岩石发生稳定蠕变的应力阀值,减缓蠕变速率。根据改进的蠕变方程进行试验数据的拟合,确定了改进的西原模型蠕变方程中的各物理量。与单轴蠕变试验结果对比表明,该模型的计算结果与试验数据吻合较好,说明改进的西原模型可较好地反映岩石加锚后的蠕变特征。研究结果对深部地下工程围岩的变形与稳定控制研究具有重要的指导意义。

Rock creep deformation and failure characteristics are discovered and rock creep velocity and propagation process under different stress paths are represented through argillac, eous sandstone creep tests. A nonlinear creep model for argillaceous sandstone is set up. Creep characteristics of surrounding rock in underground engineering under the condition of plane strain and support are represented through the application of lateral and anchoring constraints, respectively. The research results show that anchoring constraint can increase the critical stress value that rock produces stable creep and decrease creep velocity evidently. The parameters for creep constitutive equation is determined by the fit of experimental data according the improved visco-elastoplastic creep model. The calculated strains according to the obtained parameters are in good accordance with experiment results, which can be effectively validated that the improved creep model describes the creep characteristics very well. This research is very significant for the study of deformation and stability of surrounding rock mass in deep underground engineering.