裂隙辉绿岩蠕变试验及模型研究

Creep experimental study and model improvement of fissured diabase

为研究裂隙岩体的蠕变特性,对红透山铜矿深部岩体(裂隙辉绿岩)制备的标准试样进行单轴压缩蠕变试验。试验结果表明,裂隙角度对辉绿岩的强度特征影响显著,单级加载过程中应力-应变关系接近线性,整个加载过程中弹性模量为变化值,裂隙角度为3°、28.9°、63.5°、82.4°的辉绿岩长期强度约为对应单轴抗压强度的68%～75%、59%～88%、61%～76%、56%～64%。将引入的裂隙塑性元件及非线性牛顿体与Burgers模型串联,采用该裂隙岩石复合元件蠕变模型对辉绿岩蠕变曲线进行辨识,根据试样蠕变试验数据及拟合结果对裂隙岩石复合元件蠕变模型进行改进,得到裂隙岩石复合元件蠕变模型,根据试验数据对改进蠕变模型进行拟合,拟合结果与试验曲线比较吻合。上述研究结果对不同裂隙角度辉绿岩蠕变特性具有一定的参考价值。

In order to study the creep characteristics of fissured rock mass, uniaxial compression creep experiment was carried out for prepared standard specimens taken from the deep rock mass (fissured diabase) in Hongtangshan Copper Mine. Experimental results show that the effect of fracture angle on strength characteristics of diabase is significant. The stress-strain relationship is close to the linear during the single-stage loading process.The elastic modulus value changes during the whole loading process. The long-term strength of diabase with fracture angle of 3°, 28. 9°, 63. 5° and 82. 4° is only about 68%~ 75%, 59%~88%, 61%~ 76% and 56%~ 64% of the corresponding uniaxial compressive strength, respectively. Connecting the introduced fracture plastic element and nonlinear Newtonian body with the burgers model in series, identifying the creep curve of diabase by the creep model of fissured rock composite element, the creep model of fissured rock composite element was improved based on specimens'creep experimental data and fitting results, finally, the improved creep model of fissured rock composite element was obtained. According to experimental data, the improved creep model is fitted, and the fitting results are in good agreement with the experimental curve. Above results have certain reference value for creep characteristics of diabase with different fracture angles.