【作者】 肖海波；

【导师】 陈奇；

【作者基本信息】 中国地质大学（北京） ， 地质工程， 2009， 硕士

【摘要】 库岸在自然营力作用下总是在不断改变着的。波浪和岸流一方面冲击或磨蚀着边岸,另一方面又将冲蚀下来的物质或其它来源的泥沙搬运至某些岸坡堆积起来,这两方面的作用可引起库岸的进退。在库岸塌岸及库岸再造的过程中,对库区造成的危害是显而易见的。如坍塌后,大量岩土体滑进库内,产生附加淤积,减少了有效库容;坍塌严重危害库岸周边建筑的安全,使大量滩地坍失等等。因此,准确分析评价库岸稳定性和预测库岸塌岸范围尤为重要。论文以三峡库区某库岸段地质灾害勘查和初步设计为项目依托,探讨考虑河流动力条件下的岸坡塌岸预测方法。研究区位于长江右岸,三峡水库工程坝前175m蓄水后,本段长江回水位为181.6m。根据前期调查工作结论,存在库岸坍塌的危险。经分析库岸段地质环境条件,影响研究区塌岸的因素主要有地质因素、库水、降雨以及人类活动等。本文在总结传统的塌岸预测方法的基础上,引入水动力学-土力学方法对研究区进行塌岸预测。着重探讨在河流冲刷效应作用下,库岸横向展宽与冲刷下切作用对库岸稳定性评价与塌岸预测的影响,总结并完善了该方法的理论体系。水动力学-土力学方法主要采用水动力学原理计算河床淤积变形,然后用土力学原理分析库岸的稳定性,从而预测库岸塌岸范围。基于水动力学-土力学方法原理,运用VC++语言,开发了土质岸坡稳定性评价系统(简称SM-RD系统)。运用该系统,选取了3、7、10和15剖面在6种不同工况条件下,考虑冲刷20天后,计算研究区库岸横向展宽距离和评价其稳定性。评价结果表明库岸稳定性系数变小,其中工况1下,剖面10-10′变为基本稳定状态;工况3下,剖面3-3′、10-10′、15-15′变为基本稳定状态;工况6下,剖面7-7′、10-10′变为欠稳定状态。与传统预测方法进行对比,结果表明应用水动力学-土力学方法评价库岸稳定性较为符合研究区岸坡发展趋势。最后,论文将水动力学-土力学方法与传统塌岸预测方法计算结果进行对比,探讨了库岸形态变化、影响库岸后退距离因素、不同工况下稳定性变化、稳定性随时间变化,为水动力学-土力学方法应用于库岸塌岸预测奠定了理论基础。更多还原

【Abstract】 The reservoir banks are always changed by the natural force. on the one hand, Waves and shore flow impact or abrasion the banks; On the other hand, they will transport the material that was by erosion and other sources of sediment to the bank and accumulate them, the both of which cause advance and retreat of the banks. During the process of collapsing and rebuilding , the harm caused to the reservoir area is obvious. For example, if they happened to collapse, a large number of rock and soil will slip into the hangar, resulting in additional deposition, reducing the effective storage capacity, which harm Seriously the safety of the surrounding architecture, and make a large number of the beach collapse Etc. Therefore, accurate analysis and evaluation of reservoir bank stability and prediction the scope of bank collapse are particularly important.Taking a bank of the Three Gorges reservoir area for example, the paper discussed the method of predicting soil reservoir bank collapse considering the hydrodynamic conditions. The study area is located on the right bank of the Yangtze River.175m upstream of the Three Gorges reservoir water, the water level of this paragraph is 181.6m. According to preliminary conclusions of the investigation, there is the risk of reservoir banks collapsed. By Analysis of geo-environmental conditions in the study area, the factors which accept the impacts of bank collaps are mainly geological factors, reservoir water, rainfall and human activities.Based on the conclusion of traditional forecasting methods of bank collapse, this paper introduced hydrodynamic-soil-mechanic method into predicting bank collapse in the study area. Under lateral erosion, deeply discussed the impacts of channel lateral widening and bed degradation in appraising of reservoir bank stability and predicting the scope of bank collapse, and systematically summarized up and perfected the theoretical system of this method. The hydrodynamic-soil-mechanic method mainly includes calculating bed sediment deformation by principle of hydrodynamic, appraising of reservoir bank stability by Principles of Soil Mechanics, then predicting the scope of bank collapse.Based on the principle of hydrodynamic-soil-mechanic method, used VC++ language, developed a soil slope stability evaluation system (Referred to as SM-RD system). The use of this system, selected the section of 3,7,10 and 15 under 6 different working conditions, considered washing for 20 days, calculated the distance channel lateral widening and appraised of reservoir bank stability of the study area. Evaluation results show that the stability coefficient reduce: under condition 1, section 10-10 ’ turns into the basic steady-state; under condition 3, section 3-3′、10-10′、15-15′turn into the basic steady-state; under condition 6, section7-7′、10-10′becomes less stable. Compared with traditional forecasting methods, the results which appraise reservoir bank stability by hydrodynamic-soil-mechanic method are more in line with the development trend of the study area banks.Finally, compared the results calculated by hydrodynamic-soil-mechanic method to which are calculated by traditional forecasting methods, the paper deeply discussed morphological changes of reservoir banks, the impact of factors of reservoir banks back, changes in the stability of different conditions, changes in the stability in any time, which finally lay a theoretical foundation of hydrodynamic-soil-mechanic method in predicting soil reservoir bank collapse.更多还原