scholarly journals Static analysis of a high arch dam

2019 ◽  
pp. 45-57
Author(s):  
Yaser Ghafoori ◽  
Andrej Kryžanowski ◽  
Dejan Zupan

The paper presents the design and static analysis of a high arch dam. A feasibility study was conducted on the dam in the 90s and a preliminary layout was designed. However, the dam’s construction phase has been never started. In this paper, the design and layout of the dam under consideration are in accordance with the US manuals for the design of arch dams. The structure’s three-dimensional model was entered into the program SAP2000 and three-dimensional solid finite elements were used to discretize the model. This paper considers the hydrostatic pressure of the water reservoir and concrete self-weight. The analysis was performed for both the maximum and the minimum designed water level and for the case when the reservoir is empty. Special attention is given to the boundary conditions of the dam at its abutments and foundation. The results show that the planned layout is good for the dam’s construction. The arch dam’s curve transfers the loads to the abutments. The significant role of the foundation rigidity and the reservoir water level in the stress distribution and nodal displacements within the arch dam is observed.

Proceedings ◽  
2019 ◽  
Vol 24 (1) ◽  
pp. 28
Author(s):  
Chelidze ◽  
Matcharashvili ◽  
Abashidze ◽  
Dovgal ◽  
Mepharidze ◽  
...  

The 271 m high Enguri arch dam, still one of the highest arch dams in operation in the world, was built in the canyon of the Enguri river (West Georgia) in the 1970s. It is located in a zone of high seismicity (MSK intensity IX) and close to the Ingirishi active fault. The high seismic and geodynamical activities together with the large number of people living downstream of the dam make the Enguri dam a potential source of a major catastrophe in Georgia. Thus, the Enguri Dam with its 1 billion cubic meter water reservoir should be under permanent monitoring. At the same time, this area is an amazing natural laboratory, where one can investigate both tectonic and geotechnical strains and processes as well as their response to the lake load–unload impact (i.e., the reaction to a controllable loading of the Earth crust). This is an important scientific issue, connected with a fundamental problem of reservoir-induced earthquakes as well as with environmental geotechnical problems related to the safety of large dams. Application of nonlinear dynamics methods allows for the division of events, ordered by reservoir water regular strain impact from the background seismicity.


2014 ◽  
Vol 501-504 ◽  
pp. 1857-1862
Author(s):  
Xue Lu ◽  
Zhi Min Su ◽  
Feng Wang ◽  
Zhi Fang Tian ◽  
Jian Bing Zhu

Based on theories of finite element method, universal software ANSYS, by use of common software ANSYS as a platform, the influence degrees of transient temperature load and reservoir water load on arch dam stress are analyzed and computed. The result indicates that when the water level is same, the maximum tensile stress on arch dam has a close correlation with the variation of temperature, and the sensitivity of maximum tensile stress of arch dam for water temperature is higher than air temperature. The maximum tensile stress on arch dam does not correlate well with reservoir water level changes when the temperature is same. Through the non-dimensional processing on influencing factors which are temperature load and reservoir water level, the sensitivity of maximum tensile stress on arch dam for reservoir water pressure is higher than temperature load.


2018 ◽  
Vol 8 (12) ◽  
pp. 2555 ◽  
Author(s):  
Peng Lin ◽  
Pengcheng Wei ◽  
Weihao Wang ◽  
Hongfei Huang

It is of great significance to study the cracking risk, the overall stability, and the reinforcement measures of arch dams for ensuring long-term safety. In this study, the cracking types and factors of arch dams are summarized. By employing a nonlinear constitutive model relating to the yielding region, a fine three-dimensional finite element simulation of the Xulong arch dam is conducted. The results show that the dam cracking risk is localized around the outlets, the dam heel, and the left abutment. Five dam stress zones are proposed to analysis dam cracking state base of numerical results. It is recommended to use a shearing-resistance wall in the fault f57, replace the biotite enrichment zone with concrete and perform consolidation grouting or anchoring on the excavated exposed weak structural zone. Three safety factors of the Xulong arch dam are obtained, K_1 = 2~2.5; K_2 = 5; K_3 = 8.5, and the overall stability of the Xulong arch dam is guaranteed. This study demonstrates the significance of the cracking control of similar high arch dams.


Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Bing Han ◽  
Bin Tong ◽  
Jinkai Yan ◽  
Chunrong Yin ◽  
Liang Chen ◽  
...  

Reservoir landslide is a type of commonly seen geological hazards in reservoir area and could potentially cause significant risk to the routine operation of reservoir and hydropower station. It has been accepted that reservoir landslides are mainly induced by periodic variations of reservoir water level during the impoundment and drawdown process. In this study, to better understand the deformation characters and controlling factors of the reservoir landslide, a multiparameter-based monitoring program was conducted on a reservoir landslide—the Hongyanzi landslide located in Pubugou reservoir area in the southwest of China. The results indicated that significant deformation occurred to the landslide during the drawdown period; otherwise, the landslide remained stable. The major reason of reservoir landslide deformation is the generation of seepage water pressure caused by the rapidly growing water level difference inside and outside of the slope. The influences of precipitation and earthquake on the slope deformation of the Hongyanzi landslide were insignificant.


Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2011
Author(s):  
Pablo Páliz Larrea ◽  
Xavier Zapata Ríos ◽  
Lenin Campozano Parra

Despite the importance of dams for water distribution of various uses, adequate forecasting on a day-to-day scale is still in great need of intensive study worldwide. Machine learning models have had a wide application in water resource studies and have shown satisfactory results, including the time series forecasting of water levels and dam flows. In this study, neural network models (NN) and adaptive neuro-fuzzy inference systems (ANFIS) models were generated to forecast the water level of the Salve Faccha reservoir, which supplies water to Quito, the Capital of Ecuador. For NN, a non-linear input–output net with a maximum delay of 13 days was used with variation in the number of nodes and hidden layers. For ANFIS, after up to four days of delay, the subtractive clustering algorithm was used with a hyperparameter variation from 0.5 to 0.8. The results indicate that precipitation was not influencing input in the prediction of the reservoir water level. The best neural network and ANFIS models showed high performance, with a r > 0.95, a Nash index > 0.95, and a RMSE < 0.1. The best the neural network model was t + 4, and the best ANFIS model was model t + 6.


2021 ◽  
Vol 11 (4) ◽  
pp. 1381
Author(s):  
Xiuzhen Li ◽  
Shengwei Li

Forecasting the development of large-scale landslides is a contentious and complicated issue. In this study, we put forward the use of multi-factor support vector regression machines (SVRMs) for predicting the displacement rate of a large-scale landslide. The relative relationships between the main monitoring factors were analyzed based on the long-term monitoring data of the landslide and the grey correlation analysis theory. We found that the average correlation between landslide displacement and rainfall is 0.894, and the correlation between landslide displacement and reservoir water level is 0.338. Finally, based on an in-depth analysis of the basic characteristics, influencing factors, and development of landslides, three main factors (i.e., the displacement rate, reservoir water level, and rainfall) were selected to build single-factor, two-factor, and three-factor SVRM models. The key parameters of the models were determined using a grid-search method, and the models showed high accuracies. Moreover, the accuracy of the two-factor SVRM model (displacement rate and rainfall) is the highest with the smallest standard error (RMSE) of 0.00614; it is followed by the three-factor and single-factor SVRM models, the latter of which has the lowest prediction accuracy, with the largest RMSE of 0.01644.


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