节理岩体黏弹塑性流变破坏模型研究

 针对岩块与节理面的黏弹塑性流变破坏模型问题开展研究。首先提出流变瞬时强度概念，以此为基础建立岩石和节理面的非线性黏塑性流变破坏模型的一般形式，并以岩石单轴压缩蠕变破坏试验为例，分析模型描述黏塑性变形破坏的特点。然后，建立岩石完整的黏弹塑性流变破坏模型，分析其描述蠕变和松弛的特性；研究参数 对于调节岩石流变破坏过程的作用，显示模型模拟脆性–延性流变破坏的特点。与大理岩单轴压缩蠕变破坏试验进行对比，结果表明提出的模型与试验结果吻合很好，可以很好地反映岩石蠕变破坏过程。进一步对节理面的黏弹塑性流变破坏模型进行讨论，并与灌水泥浆大理岩节理的剪切蠕变试验对比，结果表明模型也能很好地反映节理面蠕变破坏特点。最后，将建立的流变破坏模型应用于大岗山引水隧洞的流变破坏分析，确定其流变破坏过程和流变破坏时间，可为进一步喷锚支护设计提供依据。针对岩石和节理面所建立的黏弹塑性流变破坏模型概念明确，能正确模拟岩石和节理面的流变破坏过程和判断破坏时间，且参数为常规试验所得，将具有良好的应用前景。

RESEARCH ON VISCO-ELASTOPLASTIC RHEOLOGICAL FAILURE MODEL OF JOINTED ROCK MASS

The visco-elastoplastic rheological failure model for rock block and joint is studied. A new concept of rheological instantaneous strength is firstly proposed；and on the basis，the nonlinear visco-plastic rheological failure model for rock and joint is established. Taking the uniaxial compression creep test for example，the visco-plastic deformation characteristics described by the new model is discussed. Then，the complete visco- elastoplastic rheological failure model for rock is established；and the creep as well as the relaxation characters of rock described by the model are analyzed. The influence of the parameter on rheological deformation and failure pattern is studied showing that the model can well reflect the brittle-ductile failure pattern of rock. By comparison with the uniaxial creep test of marble，it is found that the test and calculation by the model are coincident well，especially in the failure stage. Furthermore，the complete visco-elastoplastic rheological failure model for joint is also discussed. The calculation of creep failure process for a grouted joint is demonstrated to be well coincident with the test results. Finally，the new model is applied to the rheological failure analysis of the access tunnel of the Dagangshan hydropower station. The failure process is well modeled and the failure time is successfully forecasted，which can be the basis for further design of bolt and shotcrete support. The proposed visco-elasto- plastic rheological failure model for rock and joint is not only clear in concept，well simulating the rheological failure process and determining the failure time，but also the parameters can be easily measured by conventional tests showing the good application perspective in practical engineering.