scholarly journals A Case Study On Zoning And Construction Of Roller-Compacted-Concrete Gravity Dams

2018 ◽  
Vol 246 ◽  
pp. 02042
Author(s):  
Genquan Qin ◽  
Yangxian Chen
Keyword(s):  
Concrete Strength ◽  
Cementitious Materials ◽  
Economic Benefits ◽  
Control Measures ◽  
Gravity Dam ◽  
Jiangxi Province ◽  
Gravity Dams ◽  
Roller Compacted Concrete ◽  
Rcc Dam ◽  
Concrete Gravity Dams

In order to make full use of the concrete strength, reduce the amount of cementitious materials and simplify the temperature control measures, a roller compacted concrete (RCC) dam needs to be zoned reasonably in consideration of locations and working conditions. Taking the RCC gravity dam of Wuxikou hydropower project in Jiangxi province, this article specifies the zonation design, the problems encountered during construction stage and the corresponding measures. The results indicate that the zonation and the construction schemes of the RCC gravity dam can greatly reduce the amount of cementitious materials, improve the level of mechanization in construction, and thus accelerate the construction progress, reduce the project cost. It not only ensures the quality and safety of the project, but also achieves obvious economic benefits. It can be an important reference for zonation design and construction of similar projects.

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 Safety Monitoring Index of High Concrete Gravity Dam Based on Failure Mechanism of Instability

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Shaowei Wang ◽  
Chongshi Gu ◽  
Tengfei Bao
Keyword(s):  
Failure Mechanism ◽  
Failure Modes ◽  
Extreme Values ◽  
Safety Monitoring ◽  
Gravity Dam ◽  
Material Strength ◽  
Observation Data ◽  
Gravity Dams ◽  
Concrete Gravity Dams ◽  
Monitoring Index

Traditional methods of establishing dam safety monitoring index are mostly based on the observation data. According to the performance of dam-foundation system under the experienced loads, alarm values and extreme values are predicted for monitoring quantities. As for some dams, the potential most unfavorable loads may not yet have appeared, and dam bearing capacity may also decrease over time. Therefore, monitoring index determined by these methods can not reflect whether the dam will break or not. Based on the finite element method, to study the progressive instability failures of high concrete gravity dams under the failure modes of material strength degradation or uncertainty and extreme environmental loads during operation, methods of strength reduction and overloading are, respectively, used. Typical stages in the instability processes are identified by evaluation indicators of dam displacement, the connectivity of yield zones, and the yield volume ratio of dam concretes; then instability safety monitoring indexes are hierarchically determined according to these typical symptoms. At last, a case study is performed to give a more detailed introduction about the process of establishing safety monitoring index for high concrete gravity dams based on the failure mechanism of instability, and three grades of monitoring index related to different safety situations are established for this gravity dam.

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 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.

scholarly journals Evolution law of overall damage of concrete gravity dam under near-fault ground motion

2021 ◽  
Author(s):  
Yafei Zhai ◽  
Liaojun Zhang ◽  
Hanyun Zhang ◽  
Tianxiao Ma ◽  
Binghui Cui
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Gravity Dam ◽  
Gravity Dams ◽  
Near Fault ◽  
Concrete Gravity Dams ◽  
Fling Step ◽  
Ground Motion Records ◽  
Near Fault Ground Motion ◽  
Dynamic Damage

Abstract Strong earthquake cases of concrete gravity dams show that the foundation damage has an important influence on the seismic response and damage characteristics of the dam body. Compared with non-pulse ground motions, pulse-like near-fault ground motions have a wider response spectrum sensitive zone, which will cause more modes of the structure to respond, resulting in more serious damage to the structure. In order to study the real dynamic damage characteristics of concrete gravity dams under the action of near-fault ground motions, this paper takes Koyna gravity dam as the object and establishes a multi-coupling simulation model that can reasonably reflect the dynamic damage evolution process of dam concrete and foundation rock mass. A total of 12 near-fault ground motion records with three types of rupture directivity pulse, fling-step pulse and non-pulse are selected, deep research on the overall damage evolution law of concrete gravity dams. Considering the additional influence of different earthquake mechanisms, different site types and other factors on the study, the selected ground motion records are from the same seismic events (Chi-Chi), the same direction but different stations. The results show that the foundation of the concretes gravity dam often get damaged before the dam body under the action of strong earthquakes. Compared with the near-fault non-pulse ground motion, the structural damage of the gravity dam under the action of the near-fault directivity pulse ground motion is significantly increased, and causes greater damage and displacement response to the dam body. The near-fault fling-step pulse ground motion has the least impact on the dynamic response of the gravity dam structure.

Study on Thermal Stress and Temperature Cracks Control of Longlin Roller Compacted Concrete Gravity Dam

2012 ◽  
Vol 212-213 ◽  
pp. 912-916 ◽  
Author(s):  
Wen Yi Zheng ◽  
Peng Pan ◽  
Lie Ping Ye
Keyword(s):  
Temperature Control ◽  
Simulation Analysis ◽  
Control Function ◽  
Heat Of Hydration ◽  
Control Measures ◽  
Gravity Dam ◽  
Concrete Gravity Dam ◽  
Progress Control ◽  
Roller Compacted Concrete ◽  
Rational Construction

In order to guide temperature control design and construction and to guarantee the construction quality of roller compacted concrete (RCC) gravity dams in severe cold area, it is of great significance to carry out the simulation analysis of temperature and stress. The whole progress of construction and operation of Longlin RCC gravity dam in harsh climate region were simulated by using the heat of hydration analysis control function, construction stag analysis control function and the time-dependent material link of MIDAS.civil.2006. According to the construction process, the curves of temperature and the curves of stress were obtained. The locations where the crack ratio may exceed 20 were also obtained and the correct temperature control measures and the rational construction progress control system were pointed out.

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