水库岸坡消落带红层软岩软化崩解机理及强度演化规律研究

Red-Bed soft rock in drawdown area of reservoir bank slope will be softened and slake easily under periodically wetting-drying-cycle environment due to periodically fluctuation of reservoir water level during the course of reservoir running. When the soft rock is softened and slaking to a certain degree, its mechanical strength will decrease greatly, which will probably leads to bank slope failure. Jurassic red sandstone and amaranth mudstone in Middle Triassic Badong Formation in Three Gorges Reservoir Area are selected as research objects. The laboratory method to simulate the stress condition and periodically wetting-drying-cycle environment in drawdoen area during the course of reservoir running will be established. The experiments and tests will be carried out that on changes of microstructure, material composition, elementary composition, porosity, slaking particle graduation and mechnical strength of the two kinds of soft rocks and their mechanical strength variation under the initial stress and periodically wetting-drying-cycle environment, which will reveal mechanical strength evolution regulation and softening and slaking mechanism of the two kinds of soft rocks in drawdown area of reservoir bank slopes during the course of reservoir running. Based on results of the experiments and tests, by means of mathematical and mechanical analysis, it will be established that mathematical models of parameters of softening and slaking with reservoir running time and mechanical strength evolution with reservoir running time which considering effects of a certain stress and wetting-drying cycles on the two kinds of soft rocks during the course of reservoir running, which will give scientific support for dynamic stability analysis of the bank slopes during the course of reservoir running. The research results will have important theoretical significance and applied prospects of engineering.

水库运行期水库岸坡消落带红层软岩在周期性"湿干"交替作用下易发生软化崩解；当软化崩解发展到一定程度后，其宏观力学强度将发生大幅度降低，甚至引起岸坡失稳。本项目以三峡库区典型红层软岩--三叠系中统巴东组紫红色泥岩和侏罗系红砂岩为研究对象，建立合理模拟水库运行期岸坡消落带软岩所处的应力条件和周期性"湿干"交替作用环境的实现方法，开展水库岸坡消落带红层软岩在一定应力和周期性"湿干"交替共同作用下的细观结构、物质组成成分、孔隙度、崩解物级配等的测定和宏观力学强度变化测试试验研究，揭示岸坡消落带红层软岩在水库运行期的软化崩解机理及宏观力学强度演化规律；基于试验结果，通过数学力学分析，建立水库岸坡消落带红层软岩在岸坡应力和周期性"湿干"交替共同作用下的软化崩解特性参数及宏观力学强度随水库运行时间演化的数理模型，为水库运行期红层软岩岸坡稳定性动态分析提供科学依据。研究成果具有重要理论意义和工程应用价值。

水库运行期水库岸坡消落带红层软岩在周期性"湿干"交替作用下易发生软化崩解；当软化崩解发展到一定程度后，其宏观力学强度将发生大幅度降低，甚至引起岸坡失稳。本项目以三峡库区典型红层软岩--三叠系中统巴东组紫红色泥岩和侏罗系红砂岩为研究对象，建立了合理模拟水库运行期岸坡消落带软岩所处的应力条件和周期性"湿干"交替作用环境的实现方法，开展了水库岸坡消落带红层软岩在一定应力和周期性"湿干"交替共同作用下的细观结构、物质组成成分、孔隙度、崩解物级配等的测定和宏观力学强度变化测试试验研究，揭示了岸坡消落带红层软岩在水库运行期的软化崩解机理及宏观力学强度演化规律；基于试验结果，通过数学力学分析，建立了水库岸坡消落带红层软岩在岸坡应力和周期性"湿干"交替共同作用下的软化崩解特性参数及宏观力学强度随水库运行时间演化的数理模型，为水库运行期红层软岩岸坡稳定性动态分析提供科学依据。研究成果具有重要理论意义和工程应用价值。