Earthquake Response Of Arch Dams Research Articles

Earthquake Response of Arch Dams including Hydrodynamic effect using ABAQUS

A simple arch dam [1] is analyzed to find responses due to an earthquake, including the hydrodynamic effect of the reservoir water. The simple arch shape dam was modeled as a monolith structure, assuming the linear behavior of dam concrete. The arch dam is modeled with finite elements. The hydrodynamic effect is considered as an added mass of water adhered to the dam’s upstream surface [2]. Natural frequencies and mode shapes are computed for the dam without water and the dam with water. Time history analysis of the dam is performed for the Kern County earthquake (1952), Taft component 111 acceleration time history. The added mass of water is calculated according to the Kuo 1982 [2] research paper. Various results containing Cantilever stresses, arch stresses, and deflections are shown and plotted. Analyses are performed with the help of the Abaqus Software.

Seismic analysis of concrete arch dams considering hydrodynamic effect using Westergaard approach

Earthquake response of arch dams should be calculated under strong ground motion effects. In this study, three-dimensional linear response of an arch dam is investigated. Different ground motion effects and also foundation conditions are considered in the finite element analyses. For this purpose, the Type 3 double curvature arch dam was selected for numerical examples. All numerical analyses are carried out by SAP2000 program for empty reservoir cases. According to numerical analyses, maximum horizontal displacements and maximum normal stresses are presented by dam height in the largest section. These results are evaluated for five different elastic foundation conditions. The selected foundation conditions of the all models have different sandstone material parameters. Furthermore, near-fault and far-field ground motion effects on the selected arch dam are taken into account by different accelerograms obtained from the Loma Prieta earthquake at various distances.

Effect of foundation models on seismic response of arch dams

Simulation of the infinite foundation is a key issue in the seismic response analysis of high dams. This paper studies how the major characteristics of foundation models influence the nonlinear dynamic response of arch dams when the radiation damping effect is taken into account. The nonlinear dynamic responses of the 217 m high Yebatan arch dam under construction in China is performed as a numerical example. Several key factors, including truncated size, material damping and non-uniformity of the foundation, are analyzed comprehensively. The results show that the material damping and the size of the foundation affect the dynamic response of the dam when the incident wave method is used. Neglect of the material damping of the foundation is proposed to solve this problem, and its rationality is verified. In addition, the results show that the realistic non-uniformity of the foundation should be considered in the earthquake response of arch dams.

Earthquake damage analysis of arch dams considering dam–water–foundation interaction

A comprehensive model is integrated in this paper to analyze the nonlinear earthquake response of arch dams. The following factors are taken into account: the semi-unbounded size of foundation rock and compressible water, the opening of contraction joints, the cracking of the dam body, and the spatial variation of ground motions. As a case study, the earthquake response of the Pacoima dam to the 1994 Northridge earthquake is investigated using the proposed model. The earthquake damage is simulated based on the actual conditions during the earthquake to verify the developed analysis model. The joint opening and concrete cracking are qualitatively reproduced, wherein the ground motion excitation is spatially defined based on the acceleration records at the dam–rock interface. Several influencing factors, such as the earthquake input mechanism, shape of the thrust block, and water level, are further considered to analyze their contribution to the actual damage. The result shows that the variation of ground motions along the dam–foundation interface may be the most important factor for the damage mode of the Pacoima dam.

Earthquake response of arch dams to spatially varying ground motion

AbstractThe response of two arch dams to spatially varying ground motions recorded during earthquakes is computed by a recently developed linear analysis procedure, which includes dam–water–foundation rock interaction effects and recognizes the semi‐unbounded extent of the rock and impounded water domains. By comparing the computed and recorded responses, several issues that arise in analysis of arch dams are investigated. It is also demonstrated that spatial variations in ground motion, typically ignored in engineering practice, can have profound influence on the earthquake‐induced stresses in the dam. This influence obviously depends on the degree to which ground motion varies spatially along the dam–rock interface. Thus, for the same dam, this influence could differ from one earthquake to the next, depending on the epicenter location and the focal depth of the earthquake relative to the dam site. Copyright © 2009 John Wiley & Sons, Ltd.

Dynamic dam-reservoir interaction analysis including effect of reservoir boundary absorption

Based on the scaled boundary finite-element method, the governing equations for the analysis of dam-reservoir interaction including the reservoir boundary absorption are developed. Coupling with the equation of dam-unbounded foundation interaction, it can effectively carry out the earthquake response analysis of dam-reservoir-foundation system. The proposed approach has the advantages that the effect of compressibility of reservoir water as well as the energy absorption of reservoir boundary on the earthquake response of arch dams and gravity dams can be efficiently evaluated and higher accuracy can be achieved. In comparison with the methods available in the literature, the computational cost can be reduced to a great extent. It facilitates the application of earthquake response analysis of dam-reservoir-foundation system including reservoir boundary absorption to the engineering practice.

Elasto-plastic earthquake response of arch dams including fluid–structure interaction by the Lagrangian approach

Elasto-plastic earthquake response of arch dams including fluid–structure interaction by the Lagrangian approach is mainly investigated in this study. To this aim, three-dimensional eight-noded version of Lagrangian fluid finite element including the effects of compressible wave propagation and surface sloshing motion, and three-dimensional version of Drucker–Prager model based on associated flow rule assumption were programmed in FORTRAN language by authors and incorporated into the program NONSAP. Two new components added into the NONSAP were tested on a simple fluid tank and a simple fluid–structure system and obtained very reasonable results. Elasto-plastic earthquake analysis of an arch dam including fluid–structure interaction by the Lagrangian approach was performed using Wilson- θ method. The El Centro N–S component of Imperial Valley earthquake in 1940 was chosen as a ground motion. The component considered was applied in upstream–downstream direction. Displacements at various nodes on dam body, hydrodynamic pressures at three fluid elements near the dam–reservoir interface and yield functions at two elements predicted cracks in dam body were obtained. The elasto-plastic response of the arch dam was also compared to its linear response. It is seen that Drucker–Prager model in the representing elasto-plastic behaviour of arch dams and in estimating location of cracks in dam body is a fast tool.

Modelling of contraction joint and shear sliding effects on earthquake response of arch dams

In an arch dam, adjacent monoliths separated by vertical contraction joints may move relative to each other during an earthquake, resulting in the gradual opening and closing and possible shear movement at the joint surfaces. This paper presents the formulation of a joint constitutive model for a zero-thickness joint element that can simulate both the opening and closing and shear sliding behaviour, as well as the non-linear shear key effects of the joint. The proposed joint element has been implemented in the concrete arch dam finite element analysis program ADAP-88. The response of a typical arch dam subjected to earthquake ground motion is presented to demonstrate the capability of the proposed joint model. Results from a parametric study carried out to study the sensitivity of the response to the joint properties are discussed. The joint parameters considered in the parametric study include apparent cohesion, friction coefficient, and whether the joint has beveled or unbeveled shear key, or the joint is unrestrained in shear sliding. The analysis results show that joint opening and shear slippage at the contraction joints can have significant effects on the response of an arch dam. © 1998 John Wiley & Sons, Ltd.

Dam-Foundation Rock Interaction Effects in Earthquake Response of Arch Dams

The dynamic response of Morrow Point Dam to Taft ground motion is presented for a wide range of properties of the dam, foundation rock, impounded water, and reservoir boundary materials. Based on t...

Water Compressibility in Earthquake Response of Arch Dams

The earthquake responses of an arch dam are presented for a range of values of the Younǵs modulus of the dam, three different width‐to‐height ratios, and two values of the dam thickness. Study of these response results demonstrates that: the key parameter that determines the significance of water compressibility in the earthquake response of arch dams is Ωr, the ratio of the fundamental resonant frequency of the water in the infinite channel of the reservoir to that of the dam alone; the effects of water compressibility become insignificant for the larger values of Ωr; but for most dams, the Ωr value is smaller and thus these effects should be considered in their earthquake response analysis.

Hydrodynamic and Foundation Flexibility Effects in Earthquake Response of Arch Dams

The dynamic responses of Morrow Point Dam to Taft ground motion are presented under various assumptions for the impounded water and foundation rock for a range of properties of the alluvium and sediments at the reservoir boundary. Study of these response results demonstrates that the earthquake response of arch dams is increased by dam‐water interaction and decreased by reservoir boundary absorption, with these effects being more significant in the response of arch dams compared to gravity dams. It is also shown that the magnitudes of these effects depend significantly on the component of ground motion, and that the assumption of a rigid, nonabsorptive reservoir boundary leads to unrealistically large response for dams with impounded water, particularly due to vertical ground motion.

Earthquake analysis of arch dams including dam–water interaction, reservoir boundary absorption and foundation flexibility

AbstractThe available substructure method and computer program for the steady‐state, harmonic response analysis of arch dams, including the hydrodynamic effects, are extended to consider flexibility of the foundation rock and to include Fourier synthesis of harmonic responses to obtain the earthquake response of arch dams. By efficient evaluation of hydrodynamic terms, interpolation of frequency response functions and more efficient computer programming, the computational costs for analysing arch dams have been reduced by an order of magnitude relative to the available procedure.

Dynamic Analysis of Arch Dams Including Hydrodynamic Effects

A procedure is developed to analyze, under the assumption of linear behavior, the earthquake response of arch dams including hydrodynamic effects. The dam and fluid domain are treated as substructures and modeled with finite elements. The only geometric restriction is that an infinite fluid domain must maintain a constant cross section beyond some point in the upstream direction. For such an infinite, uniform region, a finite element discretization over the cross section is combined with a continuum representation in the upstream direction. The fluid domain model approximately accounts for the effects of foundation flexibility on hydrodynamic pressures. Computed responses of an arch dam to harmonic ground motion are presented.