西南某水电站工程边坡软岩时效变形特性研究

以研究西南某大型水电站大坝在蓄水后的长期稳定性为背景，以室内饱水直剪流变试验为手段，系统地研究了坝区内高边坡软岩的流变特性。通过对所有流变曲线的分析，获得了长期强度参数，并建立了各种类型软岩和软弱结构面的时效本构方程，得出该区软岩在饱水状态下，长期强度参数较瞬时变形降低了约60％。结论表明该区软岩的时效变形很明显，这个特性是坝区多个开挖边坡可能沿软岩蠕滑拉裂破坏的潜在因素，表明其存在对边坡及未来的稳定性起主要的控制作用。

Study on Time-Dependent Deformation of Soft Rock of the Engineering Slope in a Hydroelectric Station in Southwest of China

To study long-time stability of dam of a southwestern hydropower station after sluicing, the rheology properties of soft rock are researched by laboratory long-term direct shear in the saturated situation, the time-dependent deformation characteristics studying on the high slope soft rock and the weak structural plane have been done systematically. Through the analysis of all of the curves, the long-time strength parameters were acquired, and the time-dependent constitutive equation of each type of soft rocks and weak structural planes was established, the long-time cohesive force of the weak structural plane decreased about 60% in contrast with that of saturated quick shear test. The results indicate that time-dependent deformation of soft rock is also obvious and would be the potential factor to make the excavated slope creep-ripredly destructed along the soft rock and to play a mainly controlling role to the long-term stability.