深部斜长角闪岩流变试验及模型研究

EXPERIMENT AND MODEL STUDY OF RHEOLOGICAL CHARACTERISTICS FOR DEEP AMPHIBOLITE

以采自金川Ⅱ矿区深部斜长角闪岩为研究对象,采用分级增量加载方式进行松弛试验,并与分级增量循环加、卸载方式蠕变试验进行比较分析。岩石蠕变试验主要反映介质长期强度,而应力松弛试验可证明岩石破裂后具有残余强度。松弛曲线中存在连续型应力松弛和非连续阶梯型应力松弛,非连续阶梯型应力松弛规律与岩石试样中的微裂隙萌生、原有裂隙的扩展有着密切联系。对数据进行深入分析后,利用西原模型研究深部斜长角闪岩的黏弹塑性流变特性。分析拟合曲线与拟合参数的结果可知,西原模型的理论曲线与试验所得的松弛曲线和蠕变曲线都能较好地吻合。该模型可以较好地反映金川Ⅱ矿区深部岩石的流变特性。

Relaxation experiment on deep amphibolite samples from Jinchuan II mining area as conducted using multi-step incremental loading method. Further analysis of relaxation experimental results was made in contrast to those of creep experiment conducted by multi-step incremental cyclic loading and unloading. Creep experiment mainly reflected the long-term strength of rocks; while relaxation test proved that the rocks had residual strength after rupture. Continuous relaxation law and non-continuous ladder-type relaxation law were found through relaxation curves. The result showed that the non-continuous ladder-type relaxation law was closely related to micro-cracks initiation and original cracks propagation. The elastic and viscoelasto plastic model（K-B model） was adopted to research the visco-elasticplasticity of deep amphibolite based on the test data. The analysis of fitting curves and fitting parameters illustrated that the curves of K-B model were well agreed with those of both creep and relaxation rock samples. It was concluded that the K-B model can properly describe the rheological characteristics of amphibolite in Jinchuan II mining area.