scholarly journals Influences on the Seismic Response of a Gravity Dam with Different Foundation and Reservoir Modeling Assumptions

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3072
Author(s):  
Chen Wang ◽  
Hanyun Zhang ◽  
Yunjuan Zhang ◽  
Lina Guo ◽  
Yingjie Wang ◽  
...  
Keyword(s):  
Water Pressure ◽  
Hydrodynamic Pressure ◽  
Seismic Intensity ◽  
Dynamic Interaction ◽  
Dynamic Responses ◽  
Reservoir Modeling ◽  
Artificial Boundary ◽  
Reservoir Water ◽  
Dam Foundation ◽  
Water Simulation

The seismic design and dynamic analysis of high concrete gravity dams is a challenge due to the dams’ high levels of designed seismic intensity, dam height, and water pressure. In this study, the rigid, massless, and viscoelastic artificial boundary foundation models were established to consider the effect of dam–foundation dynamic interaction on the dynamic responses of the dam. Three reservoir water simulation methods, namely, the Westergaard added mass method, and incompressible and compressible potential fluid methods, were used to account for the effect of hydrodynamic pressure on the dynamic characteristics and seismic responses of the dam. The ranges of the truncation boundary of the foundation and reservoir in numerical analysis were further investigated. The research results showed that the viscoelastic artificial boundary foundation was more efficient than the massless foundation in the simulation of the radiation damping effect of the far-field foundation. It was found that a foundation size of 3 times the dam height was the most reasonable range of the truncation boundary of the foundation. The dynamic interaction of the reservoir foundation had a significant influence on the dam stress.

Seismic Analysis of an Earth-Rock Dam on Thick Alluvial Deposit

2012 ◽  
Vol 594-597 ◽  
pp. 1811-1815
Author(s):  
Wei Jun Cen ◽  
Shuai Wang ◽  
Zhi Xiang Yang ◽  
Hui Sun
Keyword(s):  
Seismic Analysis ◽  
Pore Water Pressure ◽  
Limit Equilibrium ◽  
Water Pressure ◽  
Permanent Deformation ◽  
Dynamic Responses ◽  
Seismic Resistance ◽  
Dam Foundation ◽  
Dynamic Displacement ◽  
Alluvial Deposit

The nonlinear dynamic FEM was applied to analyze the dynamic response of a core-wall earth-rock dam on thick loess alluvial deposit. The dynamic responses of acceleration, dynamic displacement, permanent deformation and the liquefaction state of the dam were obtained. Meanwhile, both dynamic FEM limit equilibrium method and pseudo-static method were used to access the seismic resistance of dam slope stability. The results show that dynamic responses of acceleration and dynamic displacement are reasonable. The permanent deformation is mainly concentrated in the core wall. The downstream dam slope has enough seismic resistance stability. However, there will be big dynamic pore-water pressure in the dam foundation and the loess alluvial deposit will be liquefied during the earthquake. Therefore the resistance method of liquefaction should be adopted for the foundation.

Earthquake Response Analysis of Bridge Piers in Deep Water under Hydrodynamic Pressure Action

2012 ◽  
Vol 256-259 ◽  
pp. 1480-1483
Author(s):  
Xin Huang ◽  
Zhao Wei Huang ◽  
Xue Ying Hu ◽  
Hao Liang Cai ◽  
Lin Qi ◽  
...  
Keyword(s):  
Deep Water ◽  
Interaction Analysis ◽  
Hydrodynamic Pressure ◽  
Wave Theory ◽  
Dynamic Interaction ◽  
Bridge Pier ◽  
Dynamic Responses ◽  
Bridge Piers ◽  
Response Analysis ◽  
Earthquake Excitation

In order to ensure safety of long and huge bridges in deep water under earthquake action, it is significance to consider water and bridge pier dynamic interaction. Analysis method of water-bridge pier dynamic interaction under earthquake excitation is established using radiation wave theory, and earthquake induced hydrodynamic pressure apply program is complied. Considering different earthquake wave input, earthquake induced hydrodynamic pressure influence on dynamic responses of bridge pier in deep water is further studied. The results indicate that: Dynamic response of bridge pier in deep water is augmented because of hydrodynamic pressure action. Earthquake induced hydrodynamic pressure influence on seismic responses of bridge piers in deep water will change with different input earthquake wave.

scholarly journals The Monitoring-Based Analysis on Deformation-Controlling Factors and Slope Stability of Reservoir Landslide: Hongyanzi Landslide in the Southwest of China

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Bing Han ◽  
Bin Tong ◽  
Jinkai Yan ◽  
Chunrong Yin ◽  
Liang Chen ◽  
...  
Keyword(s):  
Water Level ◽  
Water Pressure ◽  
Monitoring Program ◽  
Significant Risk ◽  
Controlling Factors ◽  
Seepage Water ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Reservoir Area ◽  
Reservoir Landslide

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.

scholarly journals Dynamic Responses of Vehicle-CRTS III Slab Track System and Vehicle Running Safety Subjected to Uniform Seismic Excitation

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Ping Lou ◽  
Kailun Gong ◽  
Chen Zhao ◽  
Qingyuan Xu ◽  
Robert K. Luo
Keyword(s):  
Reduction Rate ◽  
Seismic Intensity ◽  
Dynamic Responses ◽  
Seismic Excitation ◽  
Wheel Load ◽  
Running Speed ◽  
Running Safety ◽  
Slab Track ◽  
Track System ◽  
Highly Sensitive

The dynamic model for the vehicle-CRTS III slab track system is established subjected to uniform seismic excitation, and the calculation program with MATLAB is compiled and verified. The influences of track parameters, seismic intensity, and running speed of the vehicle on the dynamic responses of the system and the vehicle running safety are analyzed. The results show that (1) the track parameters have certain influence on the dynamic responses of the system, and the seismic intensity and the running speed of the vehicle have important influence on the vehicle running safety; (2) the derailment coefficient is highly sensitive to seismic intensity, and the wheel load reduction rate is also highly sensitive to the running speed of the vehicle.

scholarly journals Study on the mechanism of water inrush in the arid western mining area

2019 ◽  
Vol 118 ◽  
pp. 03008
Author(s):  
Chao Zheng ◽  
Lan Yu ◽  
Jiangyi He ◽  
Fengfeng Yang ◽  
Jufeng Zhang
Keyword(s):  
Large Scale ◽  
Water Pressure ◽  
Water Inrush ◽  
Hydrodynamic Pressure ◽  
Mining Area ◽  
Mining Areas ◽  
Isolation Layer ◽  
Working Face ◽  
Combined Action ◽  
Tension Fracture

The analysis found that the coal mining process in the western mining area has the mining loss and disaster effect of the water-rich aquifer of the coal seam roof, which is mainly manifested by the overburden water in the roof. On this basis, the formation and development of the separation water of the roof is proposed, and the mechanism of the water inrush from the layer is revealed. It is found that there is hydrostatic pressure and hydrodynamic pressure in the separated water, under the combined action of bed separation water pressure, the mining-induced fracture and water-isolation layer tension fracture are connected, which causes water inrushing in the coal working face of the mine, and provides a theoretical guarantee for the large-scale development of coal resources in western mining areas.

scholarly journals Stability Evaluation of Overtopped Concrete Hydraulic Structures Using Computational Fluid Dynamics

2020 ◽  
Author(s):  
Mario Freitas ◽  
Etienne Favre ◽  
Pierre Léger ◽  
Lineu José Pedroso
Keyword(s):  
Water Pressure ◽  
Back Analysis ◽  
Hydrodynamic Pressure ◽  
Flow Conditions ◽  
Gravity Dams ◽  
Pressure Fields ◽  
Dam Stability ◽  
The Stability ◽  
Resultant Forces ◽  
Safety Guidelines

A particularly challenging aspect in gravity dam stability assessment is the estimation of the induced hydrodynamic water pressure when water with significant velocity is overtopping gravity dams and flowing in or over spillway components. The water flow conditions, including the related pressure fields and resultant forces, are difficult to quantify accurately. Herein, existing dam safety guidelines to estimate the weight of the overflowing water nappe on gravity dams with rectangular crests are first reviewed. Then, a CFD methodology is developed to improve the simplified estimation of hydrodynamic pressure fields acting on the rectangular crests of submerged gravity dams. The CFD pressures are used as input data to classical structural stability analyses based on the gravity method to more adequately quantify the dam stability during overtopping. A back analysis is also performed on the stability of an existing gated spillway that was overtopped during the 1996 Saguenay flood in Québec.

scholarly journals Stability Analysis of Hydrodynamic Pressure Landslides with Different Permeability Coefficients Affected by Reservoir Water Level Fluctuations and Rainstorms

Water ◽  
2017 ◽  
Vol 9 (7) ◽  
pp. 450 ◽  
Author(s):  
Faming Huang ◽  
Xiaoyan Luo ◽  
Weiping Liu
Keyword(s):  
Water Level ◽  
Permeability Coefficient ◽  
Hydrodynamic Pressure ◽  
Water Level Fluctuations ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Stability Coefficient ◽  
Permeability Coefficients ◽  
Landslide Stability ◽  
The Stability

It is significant to study the variations in the stability coefficients of hydrodynamic pressure landslides with different permeability coefficients affected by reservoir water level fluctuations and rainstorms. The Sifangbei landslide in Three Gorges Reservoir area is used as case study. Its stability coefficients are simulated based on saturated-unsaturated seepage theory and finite element analysis. The operating conditions of stability coefficients calculation are reservoir water level variations between 175 m and 145 m, different rates of reservoir water level fluctuations, and a three-day continuous rainstorm. Results show that the stability coefficient of the hydrodynamic pressure landslide decreases with the drawdown of the reservoir water level, and a rapid drawdown rate leads to a small stability coefficient when the permeability coefficient ranges from 1.16 × 10−6 m/s to 4.64 × 10−5 m/s. Additionally, the landslide stability coefficient increases as the reservoir water level increases, and a rapid increase in the water level leads to a high stability coefficient when the permeability coefficient ranges from 1.16 × 10−6 m/s to 4.64 × 10−5 m/s. The landslide stability coefficient initially decreases and then increases as the reservoir water level declines when the permeability coefficient is greater than 4.64 × 10−5 m/s. Moreover, for structures with the same landslide, the landslide stability coefficient is most sensitive to the change in the rate of reservoir water level drawdown when the permeability coefficient increases from 1.16 × 10−6 m/s to 1.16 × 10−4 m/s. Additionally, the rate of decrease in the stability coefficient increases as the permeability coefficient increases. Finally, the three-day rainstorm leads to a significant reduction in landslide stability, and the rate of decrease in the stability coefficient initially increases and then decreases as the permeability coefficient increases.

scholarly journals Interpretasi Instrumentasi Piezometer Dalam Rangka Pemantauan Keamanan Bendungan Kedung Ombo

2021 ◽  
Vol 7 (2) ◽  
pp. 131-145
Author(s):  
Gerald Guntur Pandapotan Siregar ◽  
Fajar aldoko Kurniawan
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Water Level Fluctuations ◽  
Embankment Dam ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Embankment Dams ◽  
The World ◽  
Earthfill Dams

The embankment dam is the most widely built dam in the world, especially in Indonesia. However, embankment dams are also prone to collapse. Dam failures due to the piping process through the dam body account for 30.5% of the total dam collapses worldwide. Therefore, it is necessary to periodically monitor and evaluate the condition of pore water pressure and seepage in a dam which is usually carried out using installed instrumentation. Very little has been done on instrumentation interpretation of earthfill dams in Indonesia, which is a very worrying condition. It is possible that old or even new dams have shown behavior that leads to a decrease in safety. This condition can be monitored by instrumentation in the dam if interpreted properly. Kedung Ombo Dam as an old embankment dam but has a fairly complete instrumentation can be evaluated for safety related to pore water pressure and phreatic line (seepage line). Pore water pressure evaluation is carried out by collecting piezometer readings and reservoir water level fluctuations over a period of several years. The results of the research on the interpretation of piezometer readings indicate that the overall safety of the Kedung Ombo dam is still good in terms of pore water pressure conditions. However, there are some anomalous conditions that should be investigated further

Dynamic interaction of the low-to-medium speed maglev train and bridges with different deflection ratios: Experimental and numerical analyses

2020 ◽  
Vol 23 (11) ◽  
pp. 2399-2413 ◽  
Author(s):  
Dangxiong Wang ◽  
Xiaozhen Li ◽  
Yuwen Wang ◽  
Qikai Hu
Keyword(s):  
Interaction Model ◽  
Field Tests ◽  
Dynamic Interaction ◽  
Dynamic Responses ◽  
Vertical Deflection ◽  
Maglev Train ◽  
Simply Supported ◽  
Medium Speed ◽  
The Stability ◽  
Important Design

The deflection ratio of the bridge is an important design parameter influencing the stability of the low-to-medium speed maglev train by affecting the levitation gap. This study focuses on the dynamic interaction of the low-to-medium speed maglev train and bridges with different vertical deflection ratios and investigates the required bridge vertical deflection ratio for the stability of the maglev train. The experimental investigation is carried out first. Then, a numerical dynamic interaction model is established and verified based on the field tests. And then, the influence of the vertical deflection ratio of a 25 m simply supported girder on the dynamic responses is discussed, as well as the bridges with the same deflection ratio but different span lengths. Finally, the maximum deflection ratios for the bridges with different span lengths are proposed and also compared with that of the existing maglev lines around the world. The study shows that when the deflection ratio reaches a certain level, the dynamic responses increase dramatically. The proposed allowable deflection ratios of bridges with different span lengths can not only ensure the smooth running of the train but also reduce the costs.

Development and Challenge of the Vehicle and Highway Bridges Dynamic Interaction

2013 ◽  
Vol 574 ◽  
pp. 135-150
Author(s):  
Jia Feng Liu ◽  
Yan Li
Keyword(s):  
Analytical Model ◽  
High Speed ◽  
Engineering Application ◽  
Highway Bridges ◽  
Dynamic Interaction ◽  
Dynamic Responses ◽  
Coupling Vibration ◽  
Safety Control ◽  
Main Research ◽  
Long Span

With the development of long-span flexible bridges and the increase of highway transportation, both the dynamic responses of highway bridges under high-speed and heavy vehicles and the safety control of vehicles have deserved general concerns. First, this paper briefly discussed some researches on coupling vibration of vehicle and highway-bridges, then roundly summarized main research achievements accounting on the vehicle analytical model, bridge analytical model, surface roughness of road, numerical method of vehicle-bridge coupling vibration and some other aspects. Meanwhile, some research trends and challenge on vehicle and bridge dynamic interaction in engineering application were pointed out.

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