锦屏绿片岩分级加载流变试验研究

Study on Rheological Test of Jinping Greenschist Under Step Load

摘要:

对锦屏二级水电站引水隧洞围岩进行了分级加载流变试验,分析了试验过程中出现的现象、试样轴向、侧向应力应变关系,以及利用伯格斯模型求得的流变模型参数.分析结果表明,各试样总应变量轴向大于侧向,而各式样总流变量侧向大于轴向,流变和应变表现出不一致性;各级流变的流变量随各级应力的增加在逐级增加,各级流变的轴向流变量和侧向流变量占轴向总流变量和侧向总流变量的百分比是相似的;各试样的各级瞬时变形的弹模不断增大,符合岩石流变试验的一般性规律;在轴向和侧向两个方向上存在明显的各向异性,侧向能更快速和灵敏的反映应力变化引起的流变特性的改变;各流变参数均能正常反映绿片岩流变规律,伯格斯模型能较好的模拟锦屏绿片岩单轴流变特性.

Abstract:

Rock rheology tests were carried out on greenschist specimens from auxiliary tunnel of Jinping II Hydropower Station by step loading method. Phenomenon of the tests and the specimen axial and lateral stress-strain relationship as well as the flow obtained using the Burgers model varying parameters were analyzed. The results show that all samples’ strain on axial is greater than the lateral, while the rheology on lateral is larger than the axial,then the rheology and strain show an inconsistency. The rheological behaviours of all levels increase with the increasing of every stress levels. The axial rheology and lateral rheology of each level take the similar percentage of the total strain value on axial and lateral. Instantaneous deformation elastic model at all levels of each specimen is increasing,which complies with the general laws of rock rheology tests.Obvious anisotropy exists both in axial and lateral direction, and the phenomenon on the lateral can be more rapid and sensitive to reflect the rheological properties caused by the stress changes. The rheological parameter can reflect the greenschist rheological law, and the Burges Model can be a better simulation of the uniaxially rheological properties of Jinping greenschist.