| 摘要: |
| 心墙拱效应是影响土石坝安全稳定运行的重要因素。心墙力学特性复杂且受众多因素的影响，复杂地形地质条件对心墙拱效应具有重要影响。本文首先对比了直心墙、斜心墙、下直上斜式心墙拱效应的差异。在此基础上选取岸坡坡度、河谷宽度、覆盖层厚度以表征坝体所处的地形地质条件。基于数值计算定量研究复杂地质条件对沥青混凝土心墙拱效应的影响规律。结果表明：心墙应力拱效应主要集中在心墙中部3/4坝高附近以及靠近岸坡处。斜心墙应力拱效应相对较小，可以很好的改善心墙整体的受力状况。岸坡变陡，斜心墙整体的拱效应强度增加，应力传递的核心区域由心墙中部拓宽至心墙两岸坡。随着河谷宽度的增加，应力传递的重心逐渐由底部转移到心墙两岸及心墙中上部。而斜心墙整体的应力拱效应并非随着河谷宽度的增加单调变化，当坝轴线长度与坝高比值(L/H)增加到3~4时，河谷产生的河谷效应对斜心墙变形及拱效应影响极大的降低。随着覆盖层厚度的增加，斜心墙底部的拱效应明显增强，底部的拱效应系数分布逐渐集中化、区域化，容易产生局部的破坏。 |
| 关键词: 沥青混凝土心墙 复杂地形地质条件 数值计算 拱效应系数 |
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| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| Study on core arching of asphalt concrete core rockfill dam |
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Li Yong1, Li Yanlong1, Wen Lifeng1, Li Weimei2
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1.Xian University of Technology;2.Power China Kunming Engineering Corporation Limited
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| Abstract: |
| The arching of core is an important factor affecting the safe and stable operation of earth-rock dams. The mechanical properties of the core are complex and affected by many factors. The complex topographic and geological conditions have an important influence on the arching of the core. This paper firstly compares the differences of arching of verticle core, inclined core and lower straight upper inclined core. On this basis, slope gradient, valley width and overburden thickness are selected to characterize the topographic and geological conditions of the dam. Based on numerical calculation to quantitatively study the influence law of complex geological conditions on the arching of asphalt concrete core. The results show that the stress arching of the core is mainly concentrated near the middle 3/4 of the core height and near the bank slope. The stress arching of the inclined core is relatively small, which can improve the overall force condition of the core very well. The bank slope becomes steeper, the overall arching strength of the inclined core increases, and the core area of stress transmission is widened from the middle of the core to the slope on both sides of the core. As the width of the valley increases, the concentration of stress transfer gradually shifts from the bottom to both sides of the core and the upper part of the core. The overall stress arching of the inclined core does not change monotonously with the increase of the valley width. When the ratio of dam axis length to dam height (L / H) increases to 3 ~ 4, the valley effect generated by the valley greatly reduces the deformation and arching of the inclined core. With the increase of overburden thickness, the arching at the bottom of the inclined core is obviously enhanced, and the distribution of the arching coefficient at the bottom is gradually centralized and regionalized, which is easy to produce local damage. |
| Key words: Asphalt concrete core Complex topographic and geological conditions Numerical calculation Arching coefficient |
