项目来源：国家自然科学基金（青年项目） 项目名称：三峡库区土石堆积层滑坡水-力相互作用的滞回效应 主要负责人：王菁莪 项目时间：2016/01-2018/12 项目经费：24万元 项目简介： 库区涉水土石堆积层滑坡的变形与破坏既可能发生在水位上升阶段，也可能发生在水位下降阶段；既可能发生在水库运行初期，也可能发生在多次水位升降周期之后。其稳定性与库水位变化过程中滑坡岩土体，特别是滑带锁固段的水-力相互作用性质与滞回效应直接相关。为更加深入地认识水位变化诱发该类滑坡问题的水-力相互作用机制与滞回效应，以三峡库区典型涉水滑坡为研究对象，通过室内和原位试验测试滑坡岩土体干湿路径的水-力相互作用性质，重点分析在吸水和脱水不同路径中滞回效应对滑坡岩土体渗流、强度与变形性质的影响。通过水-力耦合方法定量化计算水位变化引起滑坡体总应力、有效应力、孔隙水压力、吸应力、静水压力以及自重的变化过程。将理论计算结果与实际滑坡多场立体监测数据进行对比验证，提出库区涉水滑坡滞回力学模型。通过涉水滑坡物理模型试验对滞回力学模型进行验证与修正，为库区涉水滑坡的长期稳定性评价与演化趋势预测提供理论依据。 The deformation and failure of reservoir wading soil-rock accumulated landslides may happen in both of the water level increasing and decreasing stages, and also in both of the preliminary operation stage of the reservoir and a certain number of years later after several water level fluctuation periods. The stability is directly correlated with the hydro-mechanical properties and hysteresis of the sliding rock and soil mass, especially the locked patches in sliding zones during the water level variation process. In order to more deeply understand the hydro-mechanical mechanism and hysteresis of reservoir induced landslides, We will take a typical soil-rock sliding debris in the Three Gorges Reservoir Area as study objects, test the hydro-mechanical properties of sliding rock and soil mass by laboratory and in-situ tests in both drying and wetting paths. Emphatically analyze the effect of hydro-mechanical hysteresis on the seepage, strength and deformation properties of sliding rock and soil mass. Establish a three dimensional geologic models of the landslide according to the investigation data, and then quantitatively calculate the variation of total stress, effective stress, pore water pressure, suction stress, hydrostatic pressure and self-weight of landslide body induced by the fluctuation of water level. Compare and verify the theoretical calculation results by the multi-physics and tridimensional field monitoring data of actual landslides, propose a hysteresis mechanical model for reservoir wading landslide. Finally, verify and correct the hysteresis mechanical model by the wading landslide physical model tests, provide the theoretical foundation for the long term stability evaluation and evolutionary trend prediction of reservoir wading landslides. |
