清原抽水蓄能电站含裂隙花岗岩三轴力学特征影响研究

Influence of fracture on triaxial mechanical characteristics of granite in Qingyuan pumped storage power station

为研究抽水蓄能电站工程中含预制裂隙花岗岩的力学特征,采用人工预制裂隙方法,设计开展了裂隙倾角与裂隙数量两个因素影响下的花岗岩三轴力学试验。试验结果表明,裂隙倾角对花岗岩承载应力的影响在于轴向应力方向,裂隙倾角愈大,愈靠近轴向应力方向,试样承载应力愈低,同时试样应变愈大。裂隙数量对花岗岩承载应力具有节点阶段特征,当裂隙数量超过9条,花岗岩承载应力差幅才显著,低于9条时差幅较小。基于试验数据获得了含裂隙花岗岩试样抗剪强度特征变化,两个裂隙特征因素对抗剪强度特征的影响主要在于黏聚力,初始裂隙物理损伤主要作用于花岗岩颗粒间黏结性。研究成果可为探讨花岗岩力学特征及工程设计提供参考。

To study the mechanical characteristics of granite with prefabricated cracks for pumped storage power stations,manual prefabricated crack method is used to design and carry out the triaxial mechanical test of granite with two influence factors-crack inclination angle and crack quantity.The results indicate that the influence of crack inclination angle on the bearing stress of granite depends on the direction of axial stress.The larger the crack inclination angle and the closer it gets to the direction of axial stress,the lower the bearing stress and the larger the strain of the sample are observed.The influence of crack quantity on the bearing stress of granite has segmental characteristic-when the crack quantity exceeds 9,the difference in bearing stress of granite is significant,and when it is less than 9,the difference is small.Based on test data,the changes in shear strength characteristics of granite are obtained.The influence of two crack characteristics on shear strength characteristics mainly lies in cohesion,and the physical damage of cracks mainly affects the cohesion between granite particles.The research results can provide reference for exploring the mechanical characteristics of granite and engineering design.