针对白鹤滩大型水电站揭露的错动带,探索了一种反映原岩应力状态的错动带试样制备方法,采用替代法对错动带进行超粒径处理,同时控制先期固结压力和稳压时间进行静载固结,并基于不同先期固结压力、不同高围压下的不固结、不排水三轴试验,结合矿物成分分析试验和扫描电镜试验,分析了不同先期固结压力下错动带的力学和变形特性。试验结果表明,不同高围压、不同固结压力下错动带应力-应变关系曲线基本表现为有剪胀行为的应变硬化型力学行为,且多为腰鼓型塑性破坏;在相同固结压力条件下,随着围压升高,错动带试样破坏应力、变形模量和泊松比均呈增大趋势,扩容效应更明显;相同围压条件下,随着先期固结压力的增大,错动带破坏应力逐步提高,弹性模量逐渐增大,而泊松比略有减小,敏感性不大;同时黏聚力和内摩擦角随固结压力的增加而分别减小和增大,呈劣化趋势。错动带微观结构的定性和定量分析进一步揭示了错动带作为一种夹杂错动后残留有岩石碎屑(块)软弱物质的颗粒类材料,在高应力下其塑性变形主要来源于颗粒破碎和颗粒的定向排列。因此,先期固结压力是影响错动带性质的重要因素。 Aimed at the dislocation belt exposed at Baihetan Hydropower Station, a method to prepare the dislocation zone sample which reflects the stress state of the original rock was explored. The dislocation zone was treated by the surrogate method and the preconsolidation pressure and stability were controlled Pressure time, and based on the different preconsolidation pressures and different consolidation pressures under different confining pressures and undrained triaxial tests, combined with the analysis of mineral composition and scanning electron microscopy, the effects of different pre-consolidation pressures Deviating with the mechanical and deformation characteristics. The experimental results show that the stress-strain curve of dislocation zone with different confining pressure and different consolidation pressure basically shows strain-hardening mechanical behavior with dilatancy behavior, and most of them are dumb drum type plastic failure. Under the same consolidation pressure conditions Under the same confining pressure, with the increase of the preconsolidation pressure, the deformation modulus and Poisson’s ratio increase with the increase of confining pressure, The failure stress of the deviating zone gradually increases, the elastic modulus increases gradually, but the Poisson’s ratio decreases slightly and the sensitivity is not great. At the same time, the cohesion and internal friction angle decrease and increase with the increase of the consolidation pressure , Showing a deteriorating trend. The qualitative and quantitative analysis of the microstructure of the dislocation zone further reveals that the dislocation zone is a kind of granular material with the weak material of rock fragments (debris) left after the dislocation. The plastic deformation of the dislocation zone mainly comes from the crushing And the orientation of the particles. Therefore, the pre-consolidation pressure is an important factor affecting the nature of the staggered zone.