Design Of Concrete Gravity Dams Research Articles

STUDI KOMPARASI PEDOMAN DESAIN SEBAGAI REFERENSI INOVASI DAN DESAIN BENDUNGAN BETON GRAVITY

Concrete gravity dams continued to develop in Indonesia even though the population is still smaller than embankment dams. Until 2021 there consist of 16 concrete gravity dams or about 7% of all dams in Indonesia. The utilization of concrete gravity dams in Indonesia is 75% for hydropower or as many as 12 dams. Concrete gravity dam is a high-risk structure so the design of concrete gravity dams must be referred to the guidelines where applicable in Indonesia and internationally with approval from Dam Safety Organization. In Indonesia, the construction of concrete gravity dams cannot be separated from the participation of design consultants from developed countries such as the UK, Japan, US, Canada, Korea, and China. Indonesian Water Resource Guidelines 2009 is formal reference that must be adhered to by all design and construction planners in Indonesia, so that designs that refer to the guidelines and manuals from foreign countries must go through a comparison and evaluation process to meet the design acceptance criteria in accordance with the Indonesian Water Resource Guidelines 2009. Comparison processes include load conditions, design concepts, seismic analysis methods, stability and stress analysis methods, and stability and stress acceptance criteria. As a results of comparison, we can get information that the Indonesian Water Resource Guidelines 2009 apply stability and stress acceptance criteria more conservative. As consequence, the investment cost for the construction of concrete gravity dams in Indonesia is becoming more expensive.Keywords: dams, concrete gravity, guidelines, comparation, stability.

Optimum design of concrete gravity dams using sequential quadratic programming algorithm

Large dams and their facilities are a part of the infrastructure of any society, and a huge amount of financial and human resources of the community are consumed to build them. Among the various types of dams, optimum design of concrete gravity dams requires special attention because these types of dams require a huge amount of concrete for their construction. In contrast, design optimisation of concrete gravity dams with regard to conditions and limitations, as well as geometric variables, can be complicated. With the appearance of various optimisation methods in recent decades, some researchers have worked on optimum design of dams. The objective of this study is to create an optimum design concrete gravity dam using a new method. For this purpose, a design methodology is proposed. According to the proposed method, a computer program is developed which carries out the optimisation process automatically. Also, numerical problems have been studied and the results obtained by the developed method have been compared to earlier studies in the literature. The results of this research study show that the novel developed method is very effective for the optimum design of gravity dams.

New explicit formulas for optimum design of concrete gravity dams

Large dams are a part of the infrastructure of any society, and a huge amount of resources are consumed to build them. Among the various types of dams, the optimum design of concrete gravity dams requires special attention because these types of dams require a huge amount of concrete for their construction. On the other hand, concrete gravity dams are among the structures whose design, regarding the acting forces, geometric parameters, and resistance and stability criteria, has some complexities. In the present study, an optimization methodology is proposed based on Sequential Quadratic Programming (SQP), and a computer program is developed to perform optimization of concrete gravity dams. The optimum results for 45 concrete gravity dams are studied and regression analyses are performed to obtain some explicit formulas for optimization of the gravity dams. The optimization of concrete gravity dams can be provided easily using the developed formulas, without the need to perform any more optimization process.

Reliability analysis of built concrete dam

Abstract The conventional design of concrete gravity dams still follows the deterministic method, which does not directly quantify the effect of uncertainties on the safety of the structure. The theory of structural reliability allows the quantification of safety of these structures, from the quantification of the inherent uncertainties in resistance and loading parameters. This article illustrates application of structural reliability theory to the case study analysis of a built concrete gravity dam. Results show that reliability of the built structure is greater than that of the designed structure. The study compares reliability for design conditions, with the corresponding safety coefficients, illustrating a lack of linearity between safety coefficients and reliability. Furthermore, the study shows which are the failure modes and the design parameters with greater influence on dam safety.

Improved optimal design of concrete gravity dams founded on anisotropic soils utilizing simulation-optimization model and hybrid genetic algorithm

ABSTRACT Incorporating numerically predicted responses of seepage characteristics based on large numbers of surrogate models to identify the optimum design of Concrete Gravity Dams (CGD) can lead to sub-optimal or local solution, even when the evolutionary Genetic Algorithm (GA) optimization solver is utilized. The optimization task aims to find the safe and minimum cost design for the CGD built on anisotropic permeable soils, considering the effect of seepage under the CGD. In each iteration of the optimization model solution, the GA-based linked Simulation-Optimization (S-O) approach evaluates the objective function and the constraints based on the responses of the Support Vector Machine (SVM) surrogate models. This paper focused on improving the GA performance to find the global or a near global optimum design of a complex optimization model, minimizing the construction cost, and providing a design safety of the CGD. This could be achieved by using the Hybrid Genetic Algorithm (HGA) optimization solver. The HGA merges two optimization search techniques: the direct search methods utilizing GA, and the gradient search method using the Interior Point Algorithm (IPA). The solution results showed that the HGA was more efficient in finding improved or, global optimum design of the CGD. Physically, the low anisotropic ratio of hydraulic conductivity (0.1, 0.3, 0.5) resulted in critical seepage characteristics, which substantially affects the optimum hydraulic design of CGD, and increases the corresponding construction cost.

Technical Issue on Uplift Pressure and Its Resolution in Structural Design of Concrete Gravity Dams

Technical Issue on Uplift Pressure and Its Resolution in Structural Design of Concrete Gravity Dams

Performance evaluation of a genetic algorithm-based linked simulation-optimization model for optimal hydraulic seepage-related design of concrete gravity dams

Concrete gravity dams (CGD) are classified as a strategic and essential structures in water resources management. Precise seepage analysis, construction cost and safety are the most important factors in the design and construction of CGD. The analytical solution and empirical seepage analysis methods under hydraulic structure are not sufficient or precise enough to provide an ideal solution for complex projects. This study concentrated on developing accurate surrogate models utilizing the Artificial Neural Network (ANN) technique, which are trained based on numerical simulated data sets generated by the seepage modelling software (SEEPW/Geo-Studio). The developed surrogate models are linked with the Genetic Algorithm (GA) optimization solver to optimize the hydraulic design considering the design safety factors and minimum construction cost of CGD. The performance of the linked simulation-optimization (S-O) model is evaluated for different design scenarios. The evaluation results demonstrate the potential applicability of the methodology for efficient, safe, and economical hydraulic design CGD on permeable soils.

Theoretical Review of Modal Analysis of Vibration and Consideration on Seismic Design of Concrete Gravity Dams Using Modified Seismic Coefficients

Theoretical Review of Modal Analysis of Vibration and Consideration on Seismic Design of Concrete Gravity Dams Using Modified Seismic Coefficients

Consideration on Effect of Excessive Load on Structural Safety and Introduction of Partial Safety Factors in Structure Design of Concrete Gravity Dams

Consideration on Effect of Excessive Load on Structural Safety and Introduction of Partial Safety Factors in Structure Design of Concrete Gravity Dams

Some Consideration on Effects of Uplift Pressure on Structure Design of Concrete Gravity Dams

Some Consideration on Effects of Uplift Pressure on Structure Design of Concrete Gravity Dams

Mathematical Consideration on Safety Factors in Structure Design of Concrete Gravity Dams

Mathematical Consideration on Safety Factors in Structure Design of Concrete Gravity Dams

Pseudo‐dynamic testing of a concrete gravity dam

SummaryInspired from the simplified single degree of freedom modeling approach used in the preliminary design of concrete gravity dams, a pseudo‐dynamic testing method was devised for the seismic testing of a concrete gravity dam section. The test specimen was a 1/75 scaled section of the 120‐m‐high monolith of the Melen Dam, one of the highest concrete gravity dams to be built in Turkey. The single degree of freedom idealization of the dam section was validated in the first stage of the study using numerical simulations including the dam–reservoir interaction. Afterwards, pseudo‐dynamic testing was conducted on the specimen using three ground motions corresponding to different hazard levels. Lateral displacement and base shear demands were measured. The crack propagation at the base of the dam was monitored with the measurement of the crack widths and the base sliding displacements. After the pseudo‐dynamic loading, a static pushover test was conducted to determine the reserve capacity of the test specimen. Despite major cracking at the base of the monolith, neither significant sliding nor a stability problem that might jeopardize the stability of the dam was observed. Copyright © 2015 John Wiley & Sons, Ltd.

A hybrid approach based on an improved gravitational search algorithm and orthogonal crossover for optimal shape design of concrete gravity dams

A hybrid approach based on an improved gravitational search algorithm (IGSA) and orthogonal crossover (OC) is proposed to efficiently find the optimal shape of concrete gravity dams. The proposed hybrid approach is called IGSA-OC. The hybrid of IGSA and the OC operator can improve the global exploration ability of the IGSA method, and increase its convergence rate. To find the optimal shape of concrete gravity dams, the interaction effects of dam–water–foundation rock subjected to earthquake loading are considered in this study. The computational cost of the optimal shape of concrete gravity dams subjected earthquake loads is usually high. Due to this problem, the weighted least squares support vector machine (WLS-SVM) regression as an efficient metamodel is utilized to considerably predict dynamic responses of gravity dams by spending low computational cost. To testify the robustness and efficiency of the proposed IGSA-OC, first, four well-known benchmark functions in literatures are optimized using the proposed IGSA-OC, and provides comparisons with the standard gravitational search algorithm (GSA) and the other modified GSA methods. Then, the optimal shape of concrete gravity dams is found using IGSA-OC. The solutions obtained by the IGSA-OC are compared with those of the standard GSA, IGSA and particle swarm optimization (PSO). The numerical results demonstrate that the proposed IGSA-OC significantly outperforms the standard GSA, IGSA and PSO.

Damage evaluation of concrete gravity dams under mainshock–aftershock seismic sequences

A large mainshock may trigger numerous aftershocks within a short period, and large aftershocks have the potential to cause additional cumulative damage to structures. This paper investigates the effects and potential of aftershocks on the accumulated damage of concrete gravity dams. For that purpose, 30 as-recorded mainshock–aftershock seismic sequences are considered in this study, and a typical two-dimensional gravity dam model subjected to the selected as-recorded seismic sequences is modeled. A Concrete Damaged Plasticity (CDP) model including the strain hardening or softening behavior is selected for the concrete material. This model is used to evaluate the nonlinear dynamic response and the seismic damage process of Koyna dam under mainshock–aftershock seismic sequences. According to the characteristics of the cracking damage development, the local and global damage indices are both established to study the influence of strong aftershocks on the cumulative damage of concrete gravity dams. From the results of this investigation, it is found that the as-recorded sequences of ground motions have a significant effect on the accumulated damage and on the design of concrete gravity dams.

Earthquake Resistant Design of Concrete Gravity Dams

After demonstrating that traditional design procedures are unrealistic, a method for design of concrete gravity dams to remain essentially within the elastic range of behavior is presented. All factors that are significant in the dynamic response of dams are considered and the capacity of concrete to support dynamic stresses in tension is recognized. In designing dams for the very intense ground shaking that may occur only rarely in highly seismic areas, limited cracking of concrete may be permitted. However, at the present time it is not possible to analytically predict, with high degree of confidence, the extent of cracking and damage that a concrete gravity dam may experience during very intense ground shaking. The research needed to improve these analysis procedures and to incorporate them in the design process is identified. The procedure presented in this paper for design of concrete gravity dams to be built in seismic regions is also applicable to evaluation of the safety of existing dams.

Theoretical investigation of the seismic stability of a lightweight concrete gravity dam

1. A considerable reduction in the dam profile with a simultaneous decrease in its asymmetry relative to the vertical does not reduce the dynamic characteristics of the structure, does not change its stability under a particular combination of loads, and hardly changes its state of stress. 2. Provision of the standard shear stability of the dam requires for both variants the use of special constructional measures in the presence of intensity 9 seismicity. 3. The complex of constructional measures in the lightweight variant, which lead to a considerable increase in its seismic stability, is promising for concrete gravity dams in regions of high seismicity. 4. To evaluate the seismic stability of dams of the indicated type it is necessary to develop appropriate dynamic criteria and to coordinate within the scope of a unified approach all standards regulating matters of the design of concrete gravity dams in seismic regions.