Damage Index Evaluation of Concrete Gravity Dam Based on Hysteresis Behavior and Stiffness Degradation Under Cyclic Loading

2017 ◽  
Vol 17 (01) ◽  
pp. 1750009 ◽  
Author(s):  
MD. Imteyaz Ansari ◽  
Pankaj Agarwal
Keyword(s):  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Damage Index ◽  
Gravity Dam ◽  
Concrete Gravity Dam ◽  
Gravity Dams ◽  
Cumulative Energy ◽  
Element Analysis ◽  
Hysteresis Behavior ◽  
Concrete Gravity Dams

An assessment of seismic vulnerability of concrete gravity dams based on the fragility curves needs a well-defined damage index (DI) to define different states of damage. The DI formulation for other types of structures is not applicable to concrete gravity dams due to the change in failure mechanism. In this study, a definition of DI based on the factor of safety against sliding is attempted and correlated with the DI formulation based on the natural period of the structure and the maximum crest displacement with cumulative energy dissipation. The proposed DI relies on the nonlinear behavior of the concrete gravity dam model under cyclic testing. The hysteresis behavior is also verified through the finite element analysis by considering the damaged plasticity behavior of concrete.

Geometric Configuration Effects on Nonlinear Seismic Behavior of Concrete Gravity Dam

2018 ◽  
Vol 12 (01) ◽  
pp. 1850003 ◽  
Author(s):  
Md. Imteyaz Ansari ◽  
Mohd Saqib ◽  
Pankaj Agarwal
Keyword(s):  
Nonlinear Dynamic ◽  
Seismic Behavior ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Geometric Configuration ◽  
Gravity Dam ◽  
Concrete Gravity Dam ◽  
Gravity Dams ◽  
Concrete Gravity Dams ◽  
Dynamic Analyses

The effects of geometric configuration on the seismic vulnerability of concrete gravity dam are discussed in the present study. The seismic vulnerability of concrete gravity dams has been represented through fragility curves obtained through incremental dynamic analyses by considering their nonlinear dynamic behavior. Five different geometries of concrete gravity dams are considered and fragility analyses are carried out on the basis of Incremental Dynamic Analyses. The effect of smoothening of re-entrant corners in the geometry of high concrete gravity dam is also presented as a possible solution.

scholarly journals Research and Application of a Seismic Damage Classification Method of Concrete Gravity Dams Using Displacement in the Crest

2020 ◽  
Vol 10 (12) ◽  
pp. 4134
Author(s):  
Xiang Lu ◽  
Liang Pei ◽  
Jiankang Chen ◽  
Zhenyu Wu ◽  
Chen Chen
Keyword(s):  
Failure Modes ◽  
Seismic Damage ◽  
Classification Method ◽  
Gravity Dam ◽  
Concrete Gravity Dam ◽  
Gravity Dams ◽  
Damage Classification ◽  
Residual Displacement ◽  
Concrete Gravity Dams ◽  
Damage Coefficient

Concrete gravity dams are one of the most common water retention structures, some of which are located in seismically active regions. Determination of damage level after earthquakes plays an important role in assessing the safety behavior of concrete dams. Compared with the traditional performance parameters obtained from numerical simulations, such as the damage coefficient, energy dissipation, failure modes, and stress state, etc., the displacement of dams can be acquired from daily monitoring data conveniently and quickly. It is of great significance for the rapid and effective evaluation of dam properties after earthquakes. The residual displacement in the concrete gravity dam crest was adopted as the performance parameter in the paper, and the linear mapping function between the residual displacement and the damage coefficient was established based on the concrete damaged plasticity model (CDP). Based on the traditional classification method with damage coefficient, a residual displacement-based seismic damage classification method with corresponding level limits was proposed. The seismic fragility analysis of Guandi concrete gravity dam was conducted as an example to illustrate the presented methodology. The results indicate that the proposed method is reasonable, effective, and can be easily applied to different projects after slight modifications.

scholarly journals The Failure Mechanism of Concrete Gravity Dams considering Different Nonlinear Models under Strong Earthquakes

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Chunli Yan ◽  
Jin Tu ◽  
Deyu Li ◽  
Shengshan Guo ◽  
Hui Liang
Keyword(s):  
Nonlinear Models ◽  
Failure Process ◽  
Damage Model ◽  
Dynamic Contact ◽  
Gravity Dam ◽  
Concrete Gravity Dam ◽  
Seismic Capacity ◽  
Gravity Dams ◽  
Strong Earthquakes ◽  
Concrete Gravity Dams

The paper focuses on the failure process and mechanism of the concrete gravity dam considering different nonlinear models under strong earthquakes. By taking a typical monolith of a concrete gravity dam as a case study, a comparative analysis of the failure process and mechanism of the dam considering the plastic damage model and the dynamic contact model, respectively, is performed using the seismic overload method. Moreover, the ultimate seismic capacity of the dam is evaluated for both of the nonlinear models. It is found that the ultimate seismic capacity of the dam is slightly different, but the failure process has significant distinctions in each model. And, the damage model is recommended when the conditions permit.

scholarly journals Numerical Simulation of Shock Response and Dynamic Fracture of a Concrete Dam Subjected to Impact Load

2016 ◽  
Vol 20 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Lu Lu ◽  
Xin Li ◽  
Jing Zhou ◽  
Genda Chen ◽  
Dong Yun
Keyword(s):  
Dynamic Fracture ◽  
Impact Load ◽  
Failure Process ◽  
Gravity Dam ◽  
Strong Impact ◽  
Concrete Gravity Dam ◽  
Gravity Dams ◽  
Concrete Gravity Dams ◽  
Shock Response ◽  
The Impact

<p>The shock response and dynamic fracture of concrete gravity dams under impact load are the key problems to evaluate the antiknock safety of the dam. This study aims at understanding the effects of impact shock on the elastic response and dynamic fracture of concrete gravity dams. Firstly, this paper uses acceleration records of a concrete gravity dam under impact to establish the correct way to determine the concrete gravity dam of the fundamental frequency and present cut sheets multi-degree-of-freedom dynamic modeling. Under strong impact loading, the constitutive relation of concrete gravity dam and the highest frequency of the impact are uncertain. So, the main advantage of this method is avoiding the use of elastic modulus in the calculation. The result indicates that the calculation method is a reliable computational method for concrete gravity dams subjected to impact. Subsequently, the failure process of dam models was numerically simulated based on ABAQUS commercial codes. Finally, this paper puts forward suggestions for future research based on the results of the analysis.</p>

scholarly journals Modelling and Characterizing a Concrete Gravity Dam for Fragility Analysis

2019 ◽  
Vol 4 (4) ◽  
pp. 62 ◽  
Author(s):  
Segura Rocio L. ◽  
Bernier Carl ◽  
Durand Capucine ◽  
Patrick Paultre
Keyword(s):  
Earthquake Engineering ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Fragility Analysis ◽  
Past Century ◽  
Concrete Gravity Dam ◽  
Gravity Dams ◽  
Eastern Canada ◽  
Safety Guidelines

Most gravity dams have been designed and built during the past century with methods of analysis that are now considered inadequate. In recent decades, knowledge of seismology, structural dynamics and earthquake engineering has greatly evolved, leading to the evaluation of existing dams to ensure public safety. This study proposes a methodology for the proper modelling and characterisation of the uncertainties to assess the seismic vulnerability of a dam-type structure. This study also includes all the required analyses and verifications of the numerical model prior to performing a seismic fragility analysis and generating the corresponding fragility curves. The procedure presented herein also makes it possible to account for the uncertainties associated with the modelling parameters as well as the randomness in the seismic solicitation. The methodology was applied to a case study dam in Eastern Canada, whose vulnerability was assessed against seismic events with characteristics established by the current safety guidelines.

scholarly journals Seepage Safety Assessment of Concrete Gravity Dam Based on Matter-Element Extension Model and FDA

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 502 ◽  
Author(s):  
Xiaoling Wang ◽  
Hongling Yu ◽  
Peng Lv ◽  
Cheng Wang ◽  
Jun Zhang ◽  
...  
Keyword(s):  
Safety Assessment ◽  
Flood Control ◽  
Gravity Dam ◽  
Concrete Gravity Dam ◽  
Gravity Dams ◽  
Concrete Gravity Dams ◽  
Extension Model ◽  
Infrastructure Project ◽  
The Stability ◽  
Criteria Importance

As an important infrastructure project, the concrete gravity dam plays an extremely important role in hydropower generation, irrigation, flood control, and other aspects. Seepage is an important factor affecting the stability of concrete gravity dams. Seepage safety assessment is of great significance to the safe operation of the dams. However, the existing seepage safety assessment models are not dynamic, and the correlation among indicators is often neglected and the overall seepage safety of the concrete gravity dams has not been considered. To solve these problems, this research proposes a dynamic matter-element extension (D-MEE) model. First, the D-MEE model is established through adroit integration of the matter-element extension (MEE) model and functional data analysis (FDA). Second, a dynamic criteria importance through the intercriteria correlation (D-CRITIC) method that can effectively consider the correlation among indicators is proposed to determine the weights. Third, the influence of different dam blocks on the overall seepage safety status is considered by constructing a spatial weight matrix. Finally, the proposed method is applied to the concrete gravity dam X in southwest China. The results show that the proposed method is effective and superior to the existing evaluation methods of seepage safety.

Application of Digital Simulation Software ANSYS in Rolling Concrete Dams Construction Technology

2011 ◽  
Vol 704-705 ◽  
pp. 352-357
Author(s):  
Gui Xiang Zeng
Keyword(s):  
Digital Simulation ◽  
Simulation Software ◽  
Construction Technology ◽  
Dynamic Features ◽  
Concrete Gravity Dam ◽  
Gravity Dams ◽  
Concrete Dam ◽  
Concrete Gravity Dams ◽  
Xinjiang Autonomous Region ◽  
Important Significance

Taking a large hydropower station in Xinjiang Autonomous Region as an example, and based on the limited unit method, the structure and seism forces features and response rules of rolling concrete gravity dam under different construction conditions were studied. The purpose for the paper is to understand dam working status under the different design conditions, and to evaluate anti-earthquake safety capability. It is proved that the present findings should play an important significance in the development of rolling concrete dam construction technology. Key words: Rolling Concrete Gravity Dams, Limited Unit Methods, Static Force Analysis, Dynamic Features.

Study on System of Gravity Dams Aided Design

2011 ◽  
Vol 255-260 ◽  
pp. 3584-3588
Author(s):  
Zhi Yuan Hou ◽  
Bin Tian ◽  
Ze Yun Xiao
Keyword(s):  
Gravity Dam ◽  
Design System ◽  
Structure Modeling ◽  
Geological Modeling ◽  
Gravity Dams ◽  
Element Analysis ◽  
3D Finite Element ◽  
3D Geological Modeling ◽  
Aided Design ◽  
Analysis Stability

Since there are some characteristics such as correlation, repeatability and integrity during the gravity dam design process, an automatic gravity dam assistant design system was established by adopting C sharp programming language, Visual Studio Development Suite as well as material mechanics and Technology of Parametric Drawing. The System includes four modules: 3D geological modeling, gravity dam structure modeling, dam sections analysis and database management. These modules realized different specialty cooperation and offered many-side analysis such as: 3D finite element analysis, stability analysis, stress analysis, section optimization and report export.

scholarly journals Study of the influence of the foundation and the reservoir on the dynamic response in a concrete gravity dam profile

2021 ◽  
Vol 14 (4) ◽  
Author(s):  
Iarly Vanderlei da Silveira ◽  
Lineu José Pedroso ◽  
Giuliano Santa Marotta
Keyword(s):  
Natural Frequencies ◽  
Free Vibration Analysis ◽  
Coupled System ◽  
Seismic Excitation ◽  
The Finite Element Method ◽  
Concrete Gravity Dam ◽  
Gravity Dams ◽  
Concrete Gravity Dams ◽  
Ansys Apdl ◽  
Maximum Stresses

abstract: This work aims to verify the influence of the foundation and the reservoir on the dynamic behavior of concrete gravity dams in terms of the natural frequencies, vibration modes for a free vibration analysis; and in terms of maximum displacements and maximum stresses at singular points of the structure for a seismic excitation. The dam-reservoir-foundation interaction was investigated through modal and transient analysis by the finite element method via ANSYS APDL software. For this study, we used a typical Brazilian dam profile and compatible data from a Brazilian earthquake for the seismic excitation. The results showed the influence of the reservoir and the foundation on the natural frequencies in the coupled system, as well as its repercussions on the response of the dam under seismic excitation.

Random Response Spectrum Analysis of Gravity Dam Classes: Simplified, Practical, and Fast Approach

2018 ◽  
Vol 34 (2) ◽  
pp. 941-975 ◽  
Author(s):  
Mohammad Amin Hariri-Ardebili ◽  
Victor E. Saouma
Keyword(s):  
Fragility Curves ◽  
Response Spectrum ◽  
Input Parameter ◽  
Gravity Dam ◽  
Random Response ◽  
Numerical Techniques ◽  
Gravity Dams ◽  
Response Spectrum Analysis ◽  
Fast Approach ◽  
Demand And Capacity

The seismic risk of concrete dams may be assessed using various numerical techniques, ranging from simplified methods to linear and nonlinear ones. Such methods should be combined with probabilistic concepts to account for the randomness in both demand and capacity. This paper proposes a random version of a simplified response spectrum method (involving equivalent static lateral forces [ESLFs]) for gravity dams by means of propagating uncertainties through the input parameters. Input parameter sensitivity is quantified and the extended procedure is explained step by step. Results are then generalized for the different dam classes. The impacts of sampling size and technique (i.e., pseudo-random and quasi-random) are also discussed. A time-based performance is evaluated and fragility curves are derived. This method may be used during the initial stages of a design process or safety analysis for existing dams.

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