李勇,李炎隆,温立峰,等. 沥青混凝土心墙堆石坝心墙拱效应研究[J]. 水利水运工程学报,2024(1):119-129.. doi: 10.12170/20221222002
引用本文: 李勇,李炎隆,温立峰,等. 沥青混凝土心墙堆石坝心墙拱效应研究[J]. 水利水运工程学报,2024(1):119-129.. doi: 10.12170/20221222002
(LI Yong, LI Yanlong, WEN Lifeng, et al. Investigation of core arching in asphalt concrete core rockfill dams[J]. Hydro-Science and Engineering, 2024(1): 119-129. (in Chinese)). doi: 10.12170/20221222002
Citation: (LI Yong, LI Yanlong, WEN Lifeng, et al. Investigation of core arching in asphalt concrete core rockfill dams[J]. Hydro-Science and Engineering, 2024(1): 119-129. (in Chinese)). doi: 10.12170/20221222002

沥青混凝土心墙堆石坝心墙拱效应研究

Investigation of core arching in asphalt concrete core rockfill dams

  • 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。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坝高附近及靠近岸坡处;斜心墙应力拱效应相对较小,可以很好地改善心墙的整体受力状况;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;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的影响大幅下降;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,容易产生局部破坏。

     

    Abstract: The arching phenomenon in the core of earth-rock dams plays a crucial role in ensuring their safety and stable operation. The mechanical properties of the core are influenced by various factors, including complex topographic and geological conditions. This study investigates and compares the arching behavior of vertical cores, inclined cores, and lower straight upper inclined cores. Additionally, slope gradient, valley width, and overburden thickness are selected as parameters to characterize the topographic and geological conditions of the dam. A quantitative analysis is conducted using numerical calculations to examine the influence of complex geological conditions on the arching behavior of asphalt concrete cores. The findings reveal that the stress arching in the core is predominantly concentrated near the middle 3/4 of the core height and along the bank slope. The arching effect in the inclined core is relatively small, contributing to an overall improvement in the core’s force distribution. As the bank slope steepens, the arching strength in the inclined core increases, resulting in a wider area of stress transmission extending from the middle of the core to both sides of the slope. Increasing the valley width causes the stress transfer concentration to gradually shift from the core’s bottom to its sides and upper part. The overall stress arching in the inclined core does not exhibit a monotonic relationship with the increase in valley width. When the ratio of dam axis length to dam height reaches 3 to 4, the valley effect significantly reduces deformation and arching in the inclined core. Moreover, as the overburden thickness increases, the arching at the bottom of the inclined core becomes more pronounced, leading to a concentrated and regionalized distribution of the arching coefficient that increases the likelihood of local damage.

     

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