【作者】 王环玲；

【导师】 徐卫亚；

【作者基本信息】 河海大学 ， 岩土工程， 2006， 博士

【摘要】 高坝泄洪雾雨所引起的岩石高边坡稳定问题是目前我国西南地区水电工程面临的一个重大难题,它涉及水力学、两相流体力学以及岩体力学等多项交叉学科。研究高坝泄洪雾雨作用下饱和非饱和岩质高边坡的稳定性,科学问题主要集中在以下三个方面:一是对实际工程所关心的高坝泄洪雾化雨的降雨强度及分布的研究,目前主要是通过原体观测和物理模型试验,得出一些经验公式进行估算,很少有深入的系统的量化分析;二是泄洪雾雨的入渗是一个饱和非饱和渗流过程,关于裂隙岩体非饱和渗流的研究,虽然提出了一些概念模型,但很多机理还不明白,非饱和状态下的岩体水力学参数也很难确定,选择什么样的数学模型也有待研究;三是雾雨影响下的岩石高边坡稳定问题,由于雾雨的入渗使边坡岩体的基质吸力降低、暂态水荷载增加,岩体强度降低,从而加速了边坡失稳,但如何来定量研究此问题还缺少可应用的成果。本文研究工作主要基于以上三个难点和科学问题,以构皮滩水电工程右岸泄洪雾雨区的边坡为研究背景,研究高坝在泄洪雾雨作用下的岩石高边坡稳定性问题。 本文的主要研究工作集中在以下几个方面: 1、限于目前对高坝泄洪雾化的雾雨强度和分布范围研究的不足以及人们对其认识的模糊性,利用模糊数学的方法研究雾雨强度和分布,分析了引起泄洪雾化的影响因子,建立了泄洪雾化的模糊数学模型。为了尽量减少人为因素给工程分析带来的主观影响,寻求出一种尽可能少使用专家经验的方法来确定模糊分析所需的隶属函数,也即在统计分析基础上并结合专家经验的方法构造隶属函数,再由模糊合成和综合评判(最大隶属度原则)来分析预报降雨强度和分布范围。 2、以构皮滩右岸雾雨区边坡为研究背景,在掌握边坡岩性、岩体结构、构造以及岩体变形和强度的基础上,划分出边坡山体工程地质岩组。重点研究了边坡卸荷带岩体特征,并在此基础上根据边坡类型、岩性及构造、岩溶发育特征、卸荷特征以及受泄洪雾化影响程度等为依据将该区自然坡体划分为五个工程地质分区。根据边坡的地表信息、开挖信息、岩层分界信息以及排水洞和帷幕信息,利用自编软件生成三维网格计算地质模型,为边坡的渗流场和应力场分析奠定基础。用此方法所建立的模型基本上保存了原山体的信息,在网格规模一定时充分利用了边坡中的控制信息,避免了建模过程中不必要的简化所造成的失真,充分的反映了原坡体面貌和人工改造后的边坡形态。更多还原

【Abstract】 High rock slope stability issue caused by flood discharge atomization of high dam is a major problem which will be faced in the water-power engineering of the west south area of our country. It is related to hydromechanics, quarter-phase fluid mechanics, rock mass mechanics etc, many crossed subjects. In general, there are three difficulty and scientific problems in the research of stability of saturated-unsaturated high rock slope under flood discharge atomization of high dam. First, the rainfall intensity and distribution of flood discharge atomization which is concerned by project can only be estimated by some empirical equations through elementary body observation and physical model tests. The in-depth, systemic quantify analysis is scared. Second, the seepage of flood discharge atomization is a saturated-unsaturated seepage flow course. The research about unsaturated seepage flow in the fracture rock mass is in the initial step, there still exits many problems, such as: the mechanics, the confirmation of hydraulics parameters of rock mass in the unsaturated phase, the choose of mathematics model. Third, the stability of high rock slope under flood discharge atomization. The flood discharge atomization seepage causes the reduction of host suction of rock slope, the increment of temporary water loading, the decrease of rock mass strength, therefore accelerates the slope failure. But the achievements of quantify research this problem is in shortage. The research work in this dissertation is about the rock slope stability issue caused by flood discharge atomization of high dam, based on the three problems above, selecting the spandrel groove slope of flood discharge atomization area in Gou Pitan right bank as the research background.The main research work in this dissertation is focused on the following: 1、 Limited by the deficiency of rainfall intensity and distribution of flood discharge atomization and the fuzziness of our understanding, the rainfall intensity and distribution of flood discharge atomization is researched by fuzzy mathematics, and influence factor of flood discharge atomization is analyzed, the fuzzy mathematics model is established. In order to reduce the subjective influence of man-made factor, one method of determining the membership function is found, that is constitute the membership function on the basis of statistical analysis, then forecast the rainfallintensity and range by the fuzzy comprehensive judge (the max degree of membership rule).2、 Choose the spandrel groove slope in Gou Pitan right bank as the research background, and divide the engineering geology petrofabric of slope mountain on the basis of familiar with the slope rock character, rock mass structure, constitution, deformation and strength of rock mass. The rock mass character of slope off-load area is major researched, and the nature slope is divided to five engineering geology area based on the slope type, rock character and constitution, carst development character, off-load character, and influence degree of flood discharge atomization. According to the slope surface information, excavation information, rock formation information, draining hole and purdah information, the three dimensional grid generated by self-programming is used to generate the compute geology model, and provide the basis for the analysis of seepage flow field and stress field of slope. The model created by this method saves the basic mountain information, making full use of control information in the slope and reflecting the original slope feature and slope shape after excavation when the grid scale is certain, avoiding the distortion in the model building process caused by simplify incorrectly.3 、 Based on the plenty of field measured fracture data, the statistical analysis about fracture density, azimuth, size, continuity, jaw opening is carried out, the random model of discrete fracture network is established on Enhanced Baecher model. The Monte Carlo random simulation is used in fracture network random simulation, thus the three-dimensional discrete fracture network figure of different dimension is got. According to the figure, the validity analysis of equivalent continue mediator model for slope seepage field is carried and seepage tensor is computed on the basis of statistical geometry data, providing important hydraulic parameter for seepage field analysis.4 、 The movement character of slope water and the factor influencing the seepage under the flood discharge atomization and rainfall seepage condition is researched. According to the control equation of saturated-unsaturated state, the integral saturated-unsaturated unsteady seepage control equation is constituted on the connection of saturation degree. The FEM computation format of mathematic model is deduced by Galerkin weighing margin method, the compute iterate mode of nonlinear FEM is developed, and the three dimensional FEM program USSEEPAGE3D of computing saturated-unsaturated unsteady seepage under ground seepage condition by FORTRAN language. This program includes fore treatment part, main computeprogram part and post treatment part, and each part has definite function meaning, can handle the complexity of practical matter and is flexible. The unsaturated hydraulic parameter problem and initial water head field problem in the FEM solve is treated, thus the solve equation is in high efficiency, fast convergence and stationary. Based on the programmed and technique method in the course of FEM computation to simulate the seepage field under flood discharge atomization of slope in Gou Pitan hydroelectric station right bank, and the result can be provided an important reference for slope rock mass seepage control.5、 The mechanics of slope failure due to atomization seepage is profound researched. Through the relation between seepage characters of fracture rock mass and stress, elastic-plastic constitutive equation of fracture rock mass and control equation of seepage field, the equivalent continue mediator model of seepage and stress field coupling is established. The two-field coupling is solved by iteration. The stability of slope is evaluated by FEM, which is used a lot in the slope stability analysis at present. In the end, for the example of flood discharge atomization region slope of Gou Pitan right bank, the component of slope rock mass under the coupling action and not including the influence of seepage field is computed, and the stability of slope is analyzed. At the same time, the influence of different seepage control measures is discussed, and the result can be provided an important science gist for safety estimate in practical project.更多还原