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Influence of Bottom Pedestal on Failure Mode of Gravity Dam under Strong Earthquake
HE Wei-ping, LIU Cong-yu, YUE Ming-kai, YAO Hui-qin
Journal of Changjiang River Scientific Research Institute ›› 2024, Vol. 41 ›› Issue (8) : 150-156.
PDF(1802 KB)
PDF(1802 KB)
Influence of Bottom Pedestal on Failure Mode of Gravity Dam under Strong Earthquake
A unique square-bottom pedestal has been adopted in the non-overflow sections of a gravity dam in southwest China. Given the region’s susceptibility to severe earthquakes, the influence of the pedestal on the failure mode and the ultimate seismic resistance capacity of the gravity dam is investigated. An acoustic-solid-coupled damage simulation method is proposed with the acoustic element simulating the reservoir water and the elasto-plastic damage model reflecting the nonlinear characteristics of concrete.The feasibility of this method in predicting structural failure modes is verified by analyzing the Koyna gravity dam under the Koyna earthquake. Comparative analyses between the pedestal section and conventional section reveal similar failure areas in the upstream slope, dam heel, and downstream face. Specific impacts of the pedestal include: new failure zones in the pedestal section; effective reduction of depth and area of the failure zone at dam heel; and generation of two development paths in the downstream failure area of pedestal section. According to the criteria of failure area breakthrough, the ultimate ground motion peak acceleration is 0.50-0.55g for conventional section and 0.55-0.60g for the pedestal section. In conclusion, the bottom pedestal enhances the ultimate seismic resistance capacity of the non-overflow dam section.
concrete gravity dam / bottom pedestal / acoustic-solid-coupled damage simulation / failure mode under strong earthquake / ultimate seismic resistance capacity
| [1] |
|
| [2] |
邱流潮. 基于联合有限-离散元法的混凝土重力坝地震破坏过程仿真[J]. 水力发电, 2009, 35(5): 36-38.
(
|
| [3] |
郭胜山, 陈厚群, 李德玉, 等. 重力坝与坝基体系地震损伤破坏分析[J]. 水利学报, 2013, 44(11):1352-1358.
(
|
| [4] |
|
| [5] |
|
| [6] |
暴艳利, 钟红, 林皋. 基于多边形比例边界有限元的重力坝地震断裂模拟[J]. 水电能源科学, 2015, 33(4): 72-75, 42.
(
|
| [7] |
|
| [8] |
|
| [9] |
|
| [10] |
徐艳杰, 牟海磊, 张楚汉, 等. 汶川地震中宝珠寺重力坝地震响应的三维有限元模拟[J]. 地球物理学报, 2012, 55(1): 293-303.
(
|
| [11] |
杨利福, 常晓林, 周伟, 等. 基于变形离散元法的重力坝地震开裂分析[J]. 振动与冲击, 2016, 35(7): 49-55.
(
|
| [12] |
闫春丽, 涂劲, 李德玉, 等. 两种非线性模型下重力坝强震破坏机理研究[J]. 水力发电, 2022, 48(3): 53-59, 93.
(
|
| [13] |
刘智, 赵兰浩, 刘勋楠, 等. 不同材料非线性组合对重力坝抗震能力的影响[J]. 振动与冲击, 2021, 40(18):124-131.
(
|
| [14] |
崔笑, 张燎军, 翟亚飞. 强震持时对重力坝坝体—坝基整体损伤演化的影响[J]. 水电能源科学, 2020, 38(7):91-94,90.
(
|
| [15] |
李晓燕, 钟红, 林皋. 地震作用下混凝土重力坝破坏过程与破坏形态数值仿真[J]. 水利学报, 2011, 42(10): 1209-1217.
(
|
| [16] |
杜荣强, 林皋, 胡志强. 混凝土重力坝动力弹塑性损伤安全评价[J]. 水利学报, 2006, 37(9): 1056-1062.
(
|
| [17] |
龚亚琦, 苏海东, 陈琴. 基于双滑面模型的混凝土重力坝深层抗滑动力稳定分析方法[J]. raybet体育在线
院报, 2019, 36(7): 125-130.
地震作用下混凝土重力坝的深层抗滑稳定是设计关心的问题。应用刚体极限平衡方法,并与有限元相结合进行重力坝深层抗滑稳定动力分析,制定了相关的计算流程:①通过黏弹性地基模型考虑地基岩体的辐射阻尼效应;②通过不同岩体中地震波速的分段处理确定入射波在不同岩体中的传播时间,从而考虑岩层的不均匀性;③应用直接计算截面内力的方法提取有限元结果中的滑动力和阻滑力,并采用规范给出的抗滑模型进行深层抗滑稳定分析;④通过敏感性分析确定了双滑面模型的2个关键参数,并比较了地基均匀性对结构变形和稳定的影响。基于上述计算流程,结合小南海重力坝工程实例,计算了地震作用下重力坝深层抗滑稳定安全系数,计算结果验证了方法的有效性,并与常规方法作了对比,其一致性较好。
(
The deep anti-sliding stability of concrete gravity dam under seismic action is an issue receiving much concerns in hydro-structure design. In this paper, an analysis method for the deep anti-sliding dynamic stability based on rigid body limit equilibrium method and finite element method is proposed and corresponding numerical process is formulated. Firstly, the radiation damping effect is considered by setting a viscous-spring artificial boundary condition in the foundation model; the seismic wave velocity and the arrival time of incident wave are set different by partitions to reflect the non-uniformity of rock strata. Furthermore, the factor of safety is calculated by decomposing external load into sliding force and drag force in the rigid finite element result by directly calculating the internal force of cross-section in the model with double sliding surfaces recommended in specification. Subsequently, the two key parameters of the model with double sliding surfaces are determined through sensitivity analysis, and the effects of foundation’s uniformity on deformation and stability of the structure are compared. The proposed method is verified to be effective by a calculation case study of Xiaonanhai gravity dam.
|
| [18] |
王维, 何丽丽, 李涛涛, 等. 基于混凝土损伤塑性模型的桥墩地震响应分析[J]. raybet体育在线
院报, 2012, 29(6): 79-82, 86.
为确保桥梁结构在强震作用下的安全，对钢筋混凝土桥墩进行了地震响应分析。基于损伤因子建立混凝土损伤塑性模型，考虑混凝土材料在动力荷载作用下的损伤演化，并利用损伤塑性模型对钢筋混凝土桥墩进行地震响应分析，同时分析了损伤塑性模型中膨胀角等参数对桥墩地震响应的影响。分析表明：混凝土损伤塑性模型能够较好地模拟混凝土构件在动力荷载作用下的损伤发展，所以在钢筋混凝土桥墩动力分析中应采用损伤塑性模型描述混凝土材料力学性能。
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To analyze the seismic response of reinforced concrete (RC) bridge pier, a plastic-damage model for concrete is established based on damage factors. The evolution of concrete damage under dynamic load is considered. In addition, the influence of model parameters such as dilation angle on the seismic response of RC bridge pier is analyzed. It's found that the damage evolution of RC bridge pier under earthquake action can be better simulated through plastic-damage model, which, therefore, could be adopted to describe mechanical properties of concrete in the dynamic analysis of RC bridge pier.
|
| [19] |
|
| [20] |
|
| [21] |
GB 50010—2010, 混凝土结构设计规范[S]. 北京: 中国建筑工业出版社, 2010.
(GB 50010—2010, Code for Design of Concrete Structures[S]. Beijing: China Architecture & Building Press, 2010. (in Chinese))
|
| [22] |
张社荣, 王高辉, 庞博慧, 等. 强震持时对混凝土重力坝损伤累积破坏的影响[J]. 水力发电学报, 2013, 32(2):201-207,227.
(
|
| [23] |
范书立, 陈明阳, 陈健云, 等. 基于能量耗散碾压混凝土重力坝地震损伤分析[J]. 振动与冲击, 2011, 30(4):271-275.
(
|
| [24] |
|
| [25] |
张超然, 陈先明, 朱红兵. 金沙江下游梯级水电站抗震安全分析[J]. 四川大学学报(工程科学版), 2009, 41(3): 1-6.
(
|
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| 〈 |
|
〉 |
