Seismic failure probability of concrete slab on CFR dams with welded and friction contacts by response surface method
Seismic failure probability of concrete slab on CFR dams with welded and friction contacts by response surface method
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DOI：
10.1016/j.soildyn.2010.06.013
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发表时间：
2010-11
影响因子：
4
通讯作者：
M. Kartal;A. Bayraktar;H. B. Başağa
中科院分区：
文献类型：
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作者：
M. Kartal;A. Bayraktar;H. B. Başağa
在本研究中，通过可靠性分析研究了具有焊接和摩擦接触的混凝土面板堆石坝（CFR）上混凝土板在地震作用下的破坏概率。为此，选取Torul CFR大坝为例，结合可靠性分析与有限元方法进行数值求解。 1992 年 Erzincan 地震加速度记录被用于考虑解卷积基岩输入模型的有限元分析。在该模型中，施加到地基基岩的地面运动是通过自由场表面记录的反卷积获得的。在材料非线性分析中，混凝土板采用 Drucker-Prager 模型，堆石体采用多线性运动硬化模型。还考虑了几何非线性。有限元模型中定义了地基土和水库水的粘性边界条件。使用基于拉格朗日方法的二维流体有限元考虑水库水的动水压力。结构连接中定义了焊接接触和基于库仑摩擦定律的摩擦接触。可靠性分析中采用改进的Rackwitz-Fiessler法和响应面法。考虑到各种厚度，混凝土板的拉伸和压缩强度被用于隐式极限状态函数。获得混凝土板中最关键点的失效概率。根据这项研究，从 CFR 大坝获得的包括摩擦接触在内的失效概率较低。当接缝考虑焊接接触时，仅当混凝土板是线性的时，由于拉应力极限状态和压应力极限状态，混凝土板失效的概率为1。混凝土板失效的最临界概率出现在混凝土板是线性的而堆石材料是非线性的情况下。如果考虑混凝土的非线性，混凝土板失效的概率就会降低。此外，动水压力也会降低混凝土板的可靠性。
In this study, failure probability of the concrete slab on concrete-faced rockfill (CFR) dams with welded and friction contact is investigated under earthquake effects by reliability analysis. For this purpose, Torul CFR dam is selected as an example and numerical solutions are performed by considering combination of reliability analysis–finite element method. 1992 Erzincan earthquake acceleration record is used in the finite element analysis considering deconvolved-base rock input model. In this model, the ground motion to be applied to the foundation base rock is obtained by deconvolution of the free-field surface record. In the materially nonlinear analysis, Drucker–Prager model is used for concrete slab and multi-linear kinematic hardening model is utilized for rockfill. Geometrically nonlinearity is also taken into account. Viscous boundary conditions are defined in the finite element model for both foundation soil and reservoir water. The hydrodynamic pressure of the reservoir water is considered using 2D fluid finite elements based on the Lagrangian approach. Both welded contact and friction contact based on the Coulomb’s friction law are defined in the structural connections. Improved Rackwitz–Fiessler method is used with response surface method in the reliability analysis. The tensile and compression strengths of the concrete slab are utilized in the implicit limit state functions considering various thicknesses. The probability of failure of the most critical points in the concrete slab is obtained. According to this study, the probabilities of failure obtained from the CFR dam including friction contact are lower. When the welded contact is considered in joints, the probability of failure of the concrete slab is 1 due to tensile stress limit state and compression stress limit state only if concrete slab is linear. The most critical probability of failure of the concrete slab appears in the case that the concrete slab is linear and rockfill is materially nonlinear. The probability of failure of the concrete slab decreases if the nonlinearity of the concrete is considered. Also, hydrodynamic pressure decreases the reliability of the concrete slab.