【作者】 张帆宇；

【导师】 刘高；

【作者基本信息】 兰州大学 ， 岩土工程， 2007， 硕士

【摘要】 大型复杂滑坡及其稳定性问题历来受到关注，虽然对之作了大量研究，但并未全面系统的理解其特征和机理，致使对其稳定性评价和发展演化趋势预测也缺乏正确合理的理论指导。目前的研究多基于就滑坡论滑坡，将滑坡演化与地质环境演化分离开或者联系不够紧密；同时忽略了滑坡物质和能量随时间变化时滑坡空间格局同步改变的现象，缺少将滑坡的时间演化和空间格局两方面入手研究滑坡时空演化的理论。在积石峡水电站坝后Ⅰ号滑坡研究过程中，结合国内外大量相关参考文献，发现滑坡演化不是纯粹、独自的随时间发展的过程，而是置身于滑坡区地质环境演化过程中，能量和物质随时间和空间不断变化的时空演化。据此，从时间演化和空间格局两方面，探讨滑坡的形成机理和演化机制，提出了滑坡的时空演化的观点。滑坡的时空演化是指在地层岩性、地质构造、地形地貌、地下水、降雨、地震、河流冲刷、风化和工程活动等因素的耦合作用下，滑坡系统的物质和能量随时间和空间而不断动态变化的过程。它既反映了滑坡在内外动力作用下物质运移形成新的空间地貌格局的变化过程，也深刻反映了能量随时间不断调整导致滑坡新的平衡状态。本文基于上述观点的认识，充分利用大量的现场调研以及丰富的勘探(钻孔、平硐和探槽)、试验和监测资料，对积石峡水电站坝后Ⅰ号滑坡开展系统研究。(1)从滑坡区工程地质环境入手，分析了该滑坡的形成条件和滑坡影响园素，阐述了滑坡的微地貌、滑体物质、滑体结构和滑带结构等特征。(2)基于该滑坡显著的分区和分层性特征，结合地质环境及其演化规律，根据地球系统科学和诸要素耦合作用的观点，采用力学理论、物理模型试验和数值模拟等方法，论证了该滑坡的形成机理，即该滑坡系顺层岩质斜坡岩体层间错动和溃屈所致。在此基础上，探讨了该滑坡的演化机制，再现其动态演化过程，分析了滑坡动态演化过程中，随着物质发生新的运移和能量重新的调整，不断改变的渭坡时空格局和滑坡演化机制。(3)基于对该滑坡的特征和演化机制的新认识，结合室内外试验，研究了滑坡体和滑带土的物理力学性质，给出了滑体和滑带土的物理力学参数。(4)采用工程地质分析、多种刚体极限平衡计算方法和位移监测，定性与定量相结合地评价了该滑坡当前稳定状态，以及各区和各层的稳定状态。(5)根据该滑坡的特征、形成机理、演化过程和当前稳定状态，结合影响因素及其未来变化特征，预测了该滑坡在泄洪雾雨、地震以及多种因素耦合作用下的发展演化趋势和运动特征。本文提出的基于地球系统科学的滑坡时空演化观点，突破了“就滑坡论滑坡”和“滑坡时空分离”的认识，强调从时间和空间上研究滑坡的形成机理和演化机制，据此可正确认识滑坡的特征，指导滑坡体(尤其滑带土)物理力学性质研究及参数选取、评价当前稳定状态、预测未来发展演化趋势以及制订相应的工程整治措施。研究结果可为复杂条件下大型滑坡的研究和工程实践提供借鉴和参考。更多还原

【Abstract】 The large-scale and complex landslides have been noticed for many years, especially their mechanism, characteristics and stability. A lot of researches had been done, however, to analyze the stability and to predict evolution trend still lack a reasonable and proper theoretical guidance because the characteristics and mechanism of these landslides have not comprehensively and systematically understood. The current studies on landslide mostly concerned about the landslide itself so that the evolution of landslides were either completely separated from or not closely enough contacted with geological environment. The theory of spatio-temporal evolution for study landslides from both temporal evolution and special pattern is desiderated because it is ignored that the synchronous change of special pattern happens when the material and energy of landslides changes with time.In the course of study on the No.1 landslide at the downstream of the Jishxia hydropower station, combined with a large number of relevant domestic and international references, it is found that landslide evolution is not pure and sole process of time, but is a continuous spatio-temporal evolution process when material and energy changes with time and space in the process of landslide’s geological environment evolution. Based on landslide is place itself in it’s geological environment, from both the time evolution and spatial pattern, the formation mechanism and evolution process of landslides are discussed and knowledge of the spatio-temporal evolution is put forward. The spatio-temporal evolution of landslide is defined as a continuous dynamical process of a landslide system in which materials and energy vary with time and space due to coupled interaction of such factors as lithology, structure, physiognomy, underground water, rainfall, earthquake, erosion of river water, weathering, human activities and the others. It shows transmission of materials will shape a new spatial physiognomy pattern and energy redistribution with time will let landslide to a new balance state.Based on lots of data of field investigation, exploration(bores, adits and coasteans), measurement, lab and field experimentation and monitoring, the No.1 landslide at the downstream of the Jishxia hydropower station was systematically studied in light of the viewpoints and knowledge mentioned as above. Firstly, start with the landslide’s engineering geological environment, the formation condition and influence factors of the landslide were analyzed, furthermore, the characteristics of the landslide were introduced and explained, including micro-physiognomy, substance, structure of slip mass and structure of sliding surface. Secondly, according to its obvious zonal and layered characteristics and the geological environments and their evolution feature, using the theory of ESS (earth system science) and the viewpoint of coupled action of factors, the formation mechanism and the dynamical process of the landslide were studied by different ways and means, such as mechanics theory, physical model experimentation, numerical simulation and so on. This landslide developed due to interlayer-shear and buckling of layered rock masses of consequent slope. The spatio-temporal pattern and the evolution mechanism varied with continuous transmission of materials and energy exchange during dynamic evolution of the landslide. Thirdly, on the basis of new understanding of the landslide’s characters and evolution mechanism, the physical and mechanics properties of both sliding body and sliding zone were studied through field and laboratory tests. The physical and mechanics parameters were consequently selected. Fourthly, current stability of the landslide was qualitatively and quantitatively researched with such methods as engineering geological analysis, several limit equilibrium methods and displacement monitoring. Then, using these results evaluate the stability of different layers and zones. Finally, based on characters, deformation mechanisms, evolution process, current stability, influence factors and their variation in future, the evolvement trend and movement character were forecasted on the following conditions, atomization-rain of jet overflow, earthquakes and coupled action of many factors.The ESS-based spatio-temporal evolution of landslides emphasized that the formation mechanisms and the dynamical evolution process of landslides must be studied from both spatial and temporal concept and modified the classic knowledge of about landslide evolution, that is, consider landslide as it stands and separately consider time and space. Based on this viewpoint, the characteristics of a landslide can be correctly cognized so as to give a rational guidance to research the physical and mechanical properties and select corresponding parameters, to evaluate current stability state, to predict future evolution trend and to map out relevant treatment measure The research results can be used for reference to study and treat other large-scale and complex landslides.更多还原