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为解决大岗山水电站坝基的辉绿岩的流变力学问题,利用RLW-1000三轴流变仪进行了不同应力路径下的三轴流变试验,得到了各工况下的应力-应变-时间曲线。结果表明:辉绿岩是典型的硬脆性岩石,存在明显的流变门槛值,破坏时表现为突发性的脆性破裂。在破裂应力水平下表现出减速蠕变、等速蠕变和加速蠕变,减速蠕变和加速蠕变历时都十分短暂。临近破裂时的横向蠕变速率均不同程度的大于轴向,这是导致岩石扩容的主要原因。由于流变过程中损伤不断发展,导致岩石整体强度下降,因此流变破坏强度普遍低于常规三轴压缩试验瞬时破坏强度。辉绿岩存在一定的蚀变现象,蚀变矿物呈细鳞片状集合体。由于蚀变带的存在,使得岩块的强度受到影响,岩石破裂极易发生在结晶程度较差的矿物颗粒部位或胶结程度较差的两种矿物接触部位。
In order to solve the rheological problems of diabase in the dam foundation of Dagangshan Hydropower Station, the triaxial rheological tests under different stress paths were carried out by RLW-1000 triaxial rheometer. The stress-strain- Time curve. The results show that diabase is a typical hard and brittle rock with obvious rheological threshold and brittle fracture when it is damaged. Decelerating creep, constant velocity creep and accelerated creep at the level of rupture stress are shown, with slow creep and accelerated creep. The lateral creep rate near the rupture is greater than the axial in varying degrees, which is the main reason for the rock expansion. The rheological failure strength is generally lower than that of the conventional triaxial compression test due to the continuous development of damage in the rheological process and the decrease of the overall strength of the rock. Diabase has some alteration phenomenon, alteration of mineral was flaky aggregates. Due to the existence of alteration zone, the strength of the rock mass is affected. The rock fracture is apt to occur in the mineral grains with poor degree of crystallinity or the two mineral contact sites with poor cementation.