超载条件下南水北调干渠膨胀土渠坡稳定性研究

发布时间：2018-06-19 05:20

本文选题：膨胀土-换填土渠坡 + 降雨渗流　；参考：《河北工程大学》2014年硕士论文

【摘要】：本文以南水北调中线工程河北省渠道邯郸-邢台段边坡工程实践为依托，对膨胀土的工程特性和边坡稳定性进行了分析研究。文章介绍了膨胀土在国内外的研究现状、膨胀土的特征、工程特性，分析了膨胀土边坡的破坏机理及对工程建筑物的危害。文章以南水北调中线工程膨胀土-换填土渠坡为背景，分别采用理论计算、实验研究和FLAC-SLOPE软件模拟，分析其在超载及渗流条件下稳定性。膨胀土-换填土渠坡的计算工况分为三种，分别是渠内无水时、渠内水深为设计水深的1/3时及渠内水深为加大水深的1/3时。其中，理论计算部分主要采用极限平衡理论来研究膨胀土边坡各工况下的稳定问题,参考条分法等极限平衡理论，对比分析了膨胀土边坡在超载、无荷载两种情况下的稳定性问题。介绍了邯郸-邢台段的工程特点、水文和地质条件，对膨胀土-换填土渠坡进行了渗流分析和稳定分析，并对计算结果做了综合分析，得出了膨胀土-换填土渠坡的破坏形态及最可能出现的滑动失稳形式。实验部分介绍了该实验的设计思路与原理，并根据几何相似、失稳临界状态相似条件，建立了膨胀土-换填土渠坡的实验模型。通过在渠坡坡顶施加外荷载(超载)，使其达到极限平衡状态，来考察渠坡失稳形态。通过实验发现，膨胀土-换填土在超载和渗流作用下，从裂隙发育至发生显著大变形失稳，有一个缓慢发展的过程，且渠坡失稳大变形区域发生于膨胀土浅表范围内。软件分析部分主要介绍了FLAC软件的应用范围，重点介绍了FLAC-slope软件的特点、方法和应用原理。运用FLAC-slope软件模拟了膨胀土-换填土渠坡在超载及降雨渗流影响时，三种工况下的稳定问题。通过模拟的结果可看出膨胀土-换填土渠坡的破坏形式。最后，，综合分析理论计算与软件模拟，可得出在堤顶超载及地下渗流影响下的膨胀土-换填土渠坡失稳最危险滑裂面是含有块间破裂面的复合曲面形式或单一曲面形式，并进一步通过实验验证了这一规律。
[Abstract]:Based on the engineering practice of Handan-Xingtai section in Hebei Province, the engineering characteristics and slope stability of expansive soil are analyzed and studied in this paper. This paper introduces the research status, characteristics and engineering characteristics of expansive soil at home and abroad, and analyzes the failure mechanism of expansive soil slope and its harm to engineering buildings. Based on the expansive soil-fill channel slope of the middle route project of South-to-North Water transfer Project, theoretical calculation, experimental study and simulation of FLAC-SLOPE software are used to analyze its stability under overload and seepage conditions. When there is no water in the channel, the depth of water in the channel is 1 / 3 of the designed water depth and the water depth in the canal is one third of that of the increase in the water depth. In the theoretical calculation part, the limit equilibrium theory is mainly used to study the stability of expansive soil slope under various working conditions. Referring to the limit equilibrium theory such as the strip method, the overloading of expansive soil slope is compared and analyzed. Stability problem in two cases without load. The engineering characteristics, hydrological and geological conditions of Handan-Xingtai section are introduced. Seepage analysis and stability analysis of expansive soil-fill canal slope are carried out, and the calculation results are analyzed synthetically. The failure pattern and the most likely sliding instability of expansive soil-fill channel slope are obtained. In the experiment part, the design idea and principle of the experiment are introduced, and the experimental model of expansive soil-replacement canal slope is established according to the similar condition of geometric similarity and unstable critical state. By applying external load (overload) on the top of the canal slope to reach the ultimate equilibrium state, the unstable state of the channel slope is investigated. It is found that under the action of overloading and seepage, the expansive soil-replacement fill has a slow development process from the development of cracks to the occurrence of significant large deformation and instability, and the large deformation region of channel slope instability occurs in the shallow range of expansive soil. In the part of software analysis, the application scope of FLAC software is introduced, and the characteristics, methods and application principle of FLAC-slope software are emphatically introduced. FLAC-Slope software is used to simulate the stability of expansive soil-replacement canal slope under the influence of overloading and rainfall seepage. According to the simulation results, the failure form of expansive soil-fill canal slope can be seen. Finally, by synthesizing theoretical calculation and software simulation, it can be concluded that the most dangerous sliding surface of expansive soil-fill canal slope under the influence of overloading on the top of embankment and underground seepage is a composite surface or a single surface with interblock fracture surface. This rule is further verified by experiments.
【学位授予单位】：河北工程大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV68;TV672

【参考文献】