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It is essential to understand the mechanics of ice load and how it affects concrete dams located in a cold climate, such as Sweden, where the temperature becomes sufficiently cold to freeze the surface of the reservoir. The purpose of this thesis is to study ice load distribution along concrete dams, and its response during the application of an ice load. Two types of concrete dams were analysed, an arch dam and a buttress dam. For these dams, the influence from different parameters on the ice load distribution along the dams is studied. In addition to this, a study on how the ice load affects dam stability had also been performed. Stability analyses based on the finite element method were performed using both linear and nonlinear formulation of the interaction behaviour between the base of the dam and the underlying rock. A parametric study of ice sheet expansion on different dam types and geometries were performed. The expansion of the ice sheet was assumed to either be caused by a constant temperature 15 ˚C uniformly distributed over the ice thickness, or by a temperature gradient from 15 ˚C at the top surface of the ice sheet and 0 ˚C at the bottom. The parametric study also includes an investigation about influence of the shape of the reservoir beaches, where it either had a perpendicular shape towards the surface of the dam, or it had an angle of 30˚ with the dam surface. In the linear stability analysis, the structure continued to deform with increasing of the resultant pressure until it reached nonlinearity. The dam deflection had a linear relation with the applied ice load force until it reached the point when structure behaviour was nonlinear. The structure failed due to sliding, overturning or combination of both sliding and overturning. A material failure can also occur if the nonlinear material behaviour is considered, however this was not considered in this study. The parametric study showed that the ice load distribution was less near the beaches, and, Det är viktigt att förstå hur islasten beter sig och hur den påverkar betongdammar som är belägna i kallt klimat, som t.ex. Sverige, där temperaturen blir tillräckligt låg för att frysa ytvattnet i en flod. Syftet med detta examensarbete är att studera isbelastningsfördelningen längs en betongdamm och dess respons under en belastningen. Två olika typer av betongdammar har analyserats, vilka är valvdamm samt lamelldamm. För dessa, studerades det hur olika parametrar påverkar lastfördelningen från istrycket längsmed dessa dammar. Slutligen har det studerats hur islasten påverkar dammsäkerheten och risken för dammbrott. Inverkan från interaktionen mellan dammen och det underliggande berget som linjär eller olinjärt har studerats i stabilitetsanalyser baserade på finita elementmetoden. En parameterstudie har också genomförts för olika dammtyper och geometrier där islasten orsakades av en expansion av isytan. Denna expansion antogs vara orsakad av antingen av en jämn fördelad temperatur över istjockleken på 15 ˚C, eller en temperaturgradient över istjockleken med +15 ˚C på den övre ytan och 0 °C vid isens bottenyta. Den parametriska studien beaktar även inverkan från utformningen av stränderna, där den har definierats som antingen vinkelrät mot dammen eller med en lutande vinkel på 30 grader. I fallet med linjära stabilitetsanalyser kommer konstruktionen att fortsätta att deformeras som ett resultat av ökande resulterande tryckkraft. Dammens deformation har ett linjärt förhållande med den applicerade islasten till dess att den når en punkt då strukturens beteende övergå till olinjärt. Strukturens brottmod kan uppstå på grund av glidning, stjälpning eller i en kombination av både glidning och stjälpning. materialbrott kan uppstå om icke-lineariteterna beaktas. Dammen gick till brott på grund av glidning, vältning eller i kombinationen av dessa då. Materialbrott kan uppstå om icke-linjära materialmodeller inkluderas, men detta beaktades dock ej i denna studie. Den parametr

It is essential to understand the mechanics of ice load and how it affects concrete dams located in a cold climate, such as Sweden, where the temperature becomes sufficiently cold to freeze the surface of the reservoir. The purpose of this thesis is to study ice load distribution along concrete dams, and its response during the application of an ice load. Two types of concrete dams were analysed, an arch dam and a buttress dam. For these dams, the influence from different parameters on the ice load distribution along the dams is studied. In addition to this, a study on how the ice load affects dam stability had also been performed. Stability analyses based on the finite element method were performed using both linear and nonlinear formulation of the interaction behaviour between the base of the dam and the underlying rock. A parametric study of ice sheet expansion on different dam types and geometries were performed. The expansion of the ice sheet was assumed to either be caused by a constant temperature 15 ˚C uniformly distributed over the ice thickness, or by a temperature gradient from 15 ˚C at the top surface of the ice sheet and 0 ˚C at the bottom. The parametric study also includes an investigation about influence of the shape of the reservoir beaches, where it either had a perpendicular shape towards the surface of the dam, or it had an angle of 30˚ with the dam surface. In the linear stability analysis, the structure continued to deform with increasing of the resultant pressure until it reached nonlinearity. The dam deflection had a linear relation with the applied ice load force until it reached the point when structure behaviour was nonlinear. The structure failed due to sliding, overturning or combination of both sliding and overturning. A material failure can also occur if the nonlinear material behaviour is considered, however this was not considered in this study. The parametric study showed that the ice load distribution was less near the beaches, and, Det är viktigt att förstå hur islasten beter sig och hur den påverkar betongdammar som är belägna i kallt klimat, som t.ex. Sverige, där temperaturen blir tillräckligt låg för att frysa ytvattnet i en flod. Syftet med detta examensarbete är att studera isbelastningsfördelningen längs en betongdamm och dess respons under en belastningen. Två olika typer av betongdammar har analyserats, vilka är valvdamm samt lamelldamm. För dessa, studerades det hur olika parametrar påverkar lastfördelningen från istrycket längsmed dessa dammar. Slutligen har det studerats hur islasten påverkar dammsäkerheten och risken för dammbrott. Inverkan från interaktionen mellan dammen och det underliggande berget som linjär eller olinjärt har studerats i stabilitetsanalyser baserade på finita elementmetoden. En parameterstudie har också genomförts för olika dammtyper och geometrier där islasten orsakades av en expansion av isytan. Denna expansion antogs vara orsakad av antingen av en jämn fördelad temperatur över istjockleken på 15 ˚C, eller en temperaturgradient över istjockleken med +15 ˚C på den övre ytan och 0 °C vid isens bottenyta. Den parametriska studien beaktar även inverkan från utformningen av stränderna, där den har definierats som antingen vinkelrät mot dammen eller med en lutande vinkel på 30 grader. I fallet med linjära stabilitetsanalyser kommer konstruktionen att fortsätta att deformeras som ett resultat av ökande resulterande tryckkraft. Dammens deformation har ett linjärt förhållande med den applicerade islasten till dess att den når en punkt då strukturens beteende övergå till olinjärt. Strukturens brottmod kan uppstå på grund av glidning, stjälpning eller i en kombination av både glidning och stjälpning. materialbrott kan uppstå om icke-lineariteterna beaktas. Dammen gick till brott på grund av glidning, vältning eller i kombinationen av dessa då. Materialbrott kan uppstå om icke-linjära materialmodeller inkluderas, men detta beaktades dock ej i denna studie. Den parametr

The objective of this study is to analyze the transient thermal and static structural behavior, and evaluate the overall dam safety of an existing 54 years old concrete arch dam in Thailand, by using a three-dimensional finite element model (FEM). The effects of thermal load and various uncertainties of material properties of dam concrete and foundation rock on the structural behavior in the static stage are clarified. A Three-Dimensional Finite Element model for the thermal transient analysis was implemented to determine the thermal distribution in the dam body. Environmental conditions, such as reservoir water temperature at all depths, ambient temperature, and solar radiation were considered in the analysis. Then, structural analysis was conducted to evaluate the deflection and stress in the dam which are caused by temperature load. The thermal analysis results indicated that the upstream face is strongly affected by reservoir water temperature while air temperature and sunlight mostly affect the downstream and crest faces. The solar radiation increases the concrete surface temperature of about 2℃ to 7℃ above the ambient temperature and causes nonuniform distribution of temperature on the dam faces. Though literature showed some significant effects of seasonal temperature variation on dam behavior, the structural analysis results in this study show that the effect caused by thermal load has a very small contribution on the stress and deflection of the dam due to low range of seasonal temperature variation in Thailand. Furthermore, a FEM model with dam-water-foundation system is established in order to evaluate the effects of various uncertainties of material properties of dam concrete and foundation rock on the dam structural behavior by conducting a parametric study. The reservoir water domain causing the hydrostatic pressure is established based on the Lagrangian approach by using modified solid elements. All main loads, such as water pressure, dam self-weight

The objective of this study is to analyze the transient thermal and static structural behavior, and evaluate the overall dam safety of an existing 54 years old concrete arch dam in Thailand, by using a three-dimensional finite element model (FEM). The effects of thermal load and various uncertainties of material properties of dam concrete and foundation rock on the structural behavior in the static stage are clarified. A Three-Dimensional Finite Element model for the thermal transient analysis was implemented to determine the thermal distribution in the dam body. Environmental conditions, such as reservoir water temperature at all depths, ambient temperature, and solar radiation were considered in the analysis. Then, structural analysis was conducted to evaluate the deflection and stress in the dam which are caused by temperature load. The thermal analysis results indicated that the upstream face is strongly affected by reservoir water temperature while air temperature and sunlight mostly affect the downstream and crest faces. The solar radiation increases the concrete surface temperature of about 2℃ to 7℃ above the ambient temperature and causes nonuniform distribution of temperature on the dam faces. Though literature showed some significant effects of seasonal temperature variation on dam behavior, the structural analysis results in this study show that the effect caused by thermal load has a very small contribution on the stress and deflection of the dam due to low range of seasonal temperature variation in Thailand. Furthermore, a FEM model with dam-water-foundation system is established in order to evaluate the effects of various uncertainties of material properties of dam concrete and foundation rock on the dam structural behavior by conducting a parametric study. The reservoir water domain causing the hydrostatic pressure is established based on the Lagrangian approach by using modified solid elements. All main loads, such as water pressure, dam self-weight

The objective of this study is to analyze the transient thermal and static structural behavior, and evaluate the overall dam safety of an existing 54 years old concrete arch dam in Thailand, by using a three-dimensional finite element model (FEM). The effects of thermal load and various uncertainties of material properties of dam concrete and foundation rock on the structural behavior in the static stage are clarified. A Three-Dimensional Finite Element model for the thermal transient analysis was implemented to determine the thermal distribution in the dam body. Environmental conditions, such as reservoir water temperature at all depths, ambient temperature, and solar radiation were considered in the analysis. Then, structural analysis was conducted to evaluate the deflection and stress in the dam which are caused by temperature load. The thermal analysis results indicated that the upstream face is strongly affected by reservoir water temperature while air temperature and sunlight mostly affect the downstream and crest faces. The solar radiation increases the concrete surface temperature of about 2℃ to 7℃ above the ambient temperature and causes nonuniform distribution of temperature on the dam faces. Though literature showed some significant effects of seasonal temperature variation on dam behavior, the structural analysis results in this study show that the effect caused by thermal load has a very small contribution on the stress and deflection of the dam due to low range of seasonal temperature variation in Thailand. Furthermore, a FEM model with dam-water-foundation system is established in order to evaluate the effects of various uncertainties of material properties of dam concrete and foundation rock on the dam structural behavior by conducting a parametric study. The reservoir water domain causing the hydrostatic pressure is established based on the Lagrangian approach by using modified solid elements. All main loads, such as water pressure, dam self-weight

The objective of this study is to analyze the transient thermal and static structural behavior, and evaluate the overall dam safety of an existing 54 years old concrete arch dam in Thailand, by using a three-dimensional finite element model (FEM). The effects of thermal load and various uncertainties of material properties of dam concrete and foundation rock on the structural behavior in the static stage are clarified. A Three-Dimensional Finite Element model for the thermal transient analysis was implemented to determine the thermal distribution in the dam body. Environmental conditions, such as reservoir water temperature at all depths, ambient temperature, and solar radiation were considered in the analysis. Then, structural analysis was conducted to evaluate the deflection and stress in the dam which are caused by temperature load. The thermal analysis results indicated that the upstream face is strongly affected by reservoir water temperature while air temperature and sunlight mostly affect the downstream and crest faces. The solar radiation increases the concrete surface temperature of about 2℃ to 7℃ above the ambient temperature and causes nonuniform distribution of temperature on the dam faces. Though literature showed some significant effects of seasonal temperature variation on dam behavior, the structural analysis results in this study show that the effect caused by thermal load has a very small contribution on the stress and deflection of the dam due to low range of seasonal temperature variation in Thailand. Furthermore, a FEM model with dam-water-foundation system is established in order to evaluate the effects of various uncertainties of material properties of dam concrete and foundation rock on the dam structural behavior by conducting a parametric study. The reservoir water domain causing the hydrostatic pressure is established based on the Lagrangian approach by using modified solid elements. All main loads, such as water pressure, dam self-weight

The objective of this study is to analyze the transient thermal and static structural behavior, and evaluate the overall dam safety of an existing 54 years old concrete arch dam in Thailand, by using a three-dimensional finite element model (FEM). The effects of thermal load and various uncertainties of material properties of dam concrete and foundation rock on the structural behavior in the static stage are clarified. A Three-Dimensional Finite Element model for the thermal transient analysis was implemented to determine the thermal distribution in the dam body. Environmental conditions, such as reservoir water temperature at all depths, ambient temperature, and solar radiation were considered in the analysis. Then, structural analysis was conducted to evaluate the deflection and stress in the dam which are caused by temperature load. The thermal analysis results indicated that the upstream face is strongly affected by reservoir water temperature while air temperature and sunlight mostly affect the downstream and crest faces. The solar radiation increases the concrete surface temperature of about 2℃ to 7℃ above the ambient temperature and causes nonuniform distribution of temperature on the dam faces. Though literature showed some significant effects of seasonal temperature variation on dam behavior, the structural analysis results in this study show that the effect caused by thermal load has a very small contribution on the stress and deflection of the dam due to low range of seasonal temperature variation in Thailand. Furthermore, a FEM model with dam-water-foundation system is established in order to evaluate the effects of various uncertainties of material properties of dam concrete and foundation rock on the dam structural behavior by conducting a parametric study. The reservoir water domain causing the hydrostatic pressure is established based on the Lagrangian approach by using modified solid elements. All main loads, such as water pressure, dam self-weight

Concrete dams located in northern regions are exposed to large seasonal temperature variations. These seasonal temperature variations have resulted in cracking in thin concrete dams. Continuous monitoring and evaluation of existing dams are important to increase the knowledge about massive concrete structures and to ensure dam safety. The aim of this degree project is to increase the knowledge about how cracking occurs in concrete dams and how it affects the dam safety. This was achieved by simulating the development of cracks in a concrete arch dam exposed to seasonal temperature variations using finite element analysis (FEA). The accuracy of the model was evaluated by comparing the results with measurements from a Swedish concrete arch dam. Finally, effect of cracks and temperature on the dam safety was investigated. FEA was used to predict the crack pattern and displacements in the arch dam. The analyses were performed both with linear elastic and nonlinear material behavior. Two models were analyzed, in one model the dam was considered to be a homogeneous arch, the other model included contraction joints. The cracking was simulated using temperature envelopes from the location of the Swedish arch dam. To evaluate the displacements in the arch, further analyses were carried out, where the cracked arch dam was exposed to the actual temperature variations at the location. The results were compared to the crack pattern and measurements of displacements of the Swedish arch dam. To investigate the effects from the cracking on the safety of the dam, a progressive failure analyses performed. The results show that the downstream face of the arch cracked under hydrostatic pressure. The cracks propagated further during winter when the temperature load was applied. The resulting crack pattern corresponded well with the survey of the cracks from the Swedish arch dam. The FE-models with nonlinear material developed a horizontal plastic hinge due to excessive cracking in a, Betongdammar belägna i nordliga klimat blir utsatta för stora säsongsburna temperaturvariationer. Dessa temperaturvariationer har orsakat sprickbildning i tunna betongdammar. Kontinuerlig övervakning och utvärdering av befintliga dammar är viktigt för att öka kunskapen om massiva betongkonstruktioner och för att säkerställa dammsäkerheten. Syftet med det här examensarbetet är att öka kunskapen om hur sprickor uppstår i valvdammar samt hur de påverkar anläggningens säkerhet. Målet är att med finit elementanalys (FEA) analysera uppsprickningen av betongen i en valvdamm som påverkas av säsongsburna temperaturvariationer. Tillförlitligheten i modellen utvärderas genom att jämföra med mätningar från en svensk valvdamm av liknande dimensioner. Slutligen utvärderas hur dammens säkerhet påverkas av sprickbildningen. FE-analys användes för att förutsäga sprickmönstret och förskjutningarna i valvdammen. Analyserna utfördes både med linjärelastiskt och icke-linjärt materialbeteende. Två modeller användes i analysen, i ena modellen betraktades dammen som homogen och i den andra inkluderades gjutfogar. Sprickmönstret simulerades med temperaturcykler baserade på extremtemperaturer tagna intill den svenska valvdammen. För att utvärdera förskjutningarna i dammen gjordes vidare analyser där den spruckna dammen utsattes för temperaturvariationer uppmätta från samma plasts. Resultaten från analysen jämfördes med mätningar av förskjutningar och kartering av sprickor från den svenska valvdammen. För att undersöka hur säkerheten påverkades av sprickbildningen utfördes progressiv brottanalys. Resultaten visar att dammen spricker på nedströmssidan när den utsätts för vattentryck. Sprickorna fortplantas under vintern när temperaturlasten appliceras. Sprickmönstret stämmer överens med kartering av den verkliga dammen. FE-modellerna med icke-linjärt materialbeteende utvecklade en plastisk led längs horisontella sprickor halvvägs ner från krönet. Den plastiska leden påverkade dammens utböjd

Concrete dams located in northern regions are exposed to large seasonal temperature variations. These seasonal temperature variations have resulted in cracking in thin concrete dams. Continuous monitoring and evaluation of existing dams are important to increase the knowledge about massive concrete structures and to ensure dam safety. The aim of this degree project is to increase the knowledge about how cracking occurs in concrete dams and how it affects the dam safety. This was achieved by simulating the development of cracks in a concrete arch dam exposed to seasonal temperature variations using finite element analysis (FEA). The accuracy of the model was evaluated by comparing the results with measurements from a Swedish concrete arch dam. Finally, effect of cracks and temperature on the dam safety was investigated. FEA was used to predict the crack pattern and displacements in the arch dam. The analyses were performed both with linear elastic and nonlinear material behavior. Two models were analyzed, in one model the dam was considered to be a homogeneous arch, the other model included contraction joints. The cracking was simulated using temperature envelopes from the location of the Swedish arch dam. To evaluate the displacements in the arch, further analyses were carried out, where the cracked arch dam was exposed to the actual temperature variations at the location. The results were compared to the crack pattern and measurements of displacements of the Swedish arch dam. To investigate the effects from the cracking on the safety of the dam, a progressive failure analyses performed. The results show that the downstream face of the arch cracked under hydrostatic pressure. The cracks propagated further during winter when the temperature load was applied. The resulting crack pattern corresponded well with the survey of the cracks from the Swedish arch dam. The FE-models with nonlinear material developed a horizontal plastic hinge due to excessive cracking in a, Betongdammar belägna i nordliga klimat blir utsatta för stora säsongsburna temperaturvariationer. Dessa temperaturvariationer har orsakat sprickbildning i tunna betongdammar. Kontinuerlig övervakning och utvärdering av befintliga dammar är viktigt för att öka kunskapen om massiva betongkonstruktioner och för att säkerställa dammsäkerheten. Syftet med det här examensarbetet är att öka kunskapen om hur sprickor uppstår i valvdammar samt hur de påverkar anläggningens säkerhet. Målet är att med finit elementanalys (FEA) analysera uppsprickningen av betongen i en valvdamm som påverkas av säsongsburna temperaturvariationer. Tillförlitligheten i modellen utvärderas genom att jämföra med mätningar från en svensk valvdamm av liknande dimensioner. Slutligen utvärderas hur dammens säkerhet påverkas av sprickbildningen. FE-analys användes för att förutsäga sprickmönstret och förskjutningarna i valvdammen. Analyserna utfördes både med linjärelastiskt och icke-linjärt materialbeteende. Två modeller användes i analysen, i ena modellen betraktades dammen som homogen och i den andra inkluderades gjutfogar. Sprickmönstret simulerades med temperaturcykler baserade på extremtemperaturer tagna intill den svenska valvdammen. För att utvärdera förskjutningarna i dammen gjordes vidare analyser där den spruckna dammen utsattes för temperaturvariationer uppmätta från samma plasts. Resultaten från analysen jämfördes med mätningar av förskjutningar och kartering av sprickor från den svenska valvdammen. För att undersöka hur säkerheten påverkades av sprickbildningen utfördes progressiv brottanalys. Resultaten visar att dammen spricker på nedströmssidan när den utsätts för vattentryck. Sprickorna fortplantas under vintern när temperaturlasten appliceras. Sprickmönstret stämmer överens med kartering av den verkliga dammen. FE-modellerna med icke-linjärt materialbeteende utvecklade en plastisk led längs horisontella sprickor halvvägs ner från krönet. Den plastiska leden påverkade dammens utböjd

Flera dammkonstruktioner i Norden utsätts för stora temperaturvariationer mellan sommar och vinter. I norra Sverige kan dammar vara utsatta för temperaturvariationer på upp emot 60–70 °C. Detta resulterar ofta i sprickbildning i betongen vilket medför utmaningar vid både utformning av nya dammar och underhåll av befintliga. Säsongmässiga temperaturvariationer är den dominerande orsaken till sprickbildning i stora, massiva betongkonstruktioner. Skillnaden i temperatur mellan uppström- och nedströmssidan orsakar en temperaturgradient i dammkroppen vilket leder till en ojämn expansion eller krympning i betongen. Detta examensarbete är en del av ett initiativ från ICOLD-kommitten "Computational Aspects of Dam Analysis and Design" med mål att hitta en lämplig FE-metodologi för att bättre kunna analysera dessa typer av fenomen. En valvdamm i norra Sverige analyserades för att undersöka hur temperaturvariationer orsakar deformationer och påverkar spricktillväxt i dammkroppen. Arbetet består av tre delar som analyserar temperaturfördelningen, deformationen och spricktillväxten i dammen. Finita elementprogrammet Abaqus 2016 användes i alla analyser. Analyserna fastställer att säsongmässiga temperaturvariationer har en betydande påverkan på det mekaniska beteendet i valvdammar i kalla klimat. Kalla vintrar har en stor inverkan på valdammar avseende deformation och spricktillväxt då medeltemperaturen i dammen understiger 0 °C., Dams located in the Nordic countries are subjected to large temperature variations between summer and winter. In the northern part of Sweden dams are subjected to temperature variations of up to 60-70 °C. This often results in cracking of the concrete and causes challenges in the design of new dams as well as maintenance of existing dams. Seasonal temperature variation has been found to be the dominant cause of cracking in large, massive concrete structures. The difference in temperature of the water on the upstream side, and the ambient air on the downstream side, causes a temperature gradient in the dam which results in non-uniform expansion and contraction of the concrete. This master dissertation is a part of an initiative from the ICOLD-committee "Computational Aspects of Dam Analysis and Design" with the aim to find a suitable FE-methodology to better analyse these kinds of phenomena. An arch dam located in northern Sweden is analysed in order to see how temperature variations would influence the displacement and cracking of the dam. The work consisted of three parts which analyses the temperature distribution, the displacement and the crack propagation of the dam. The finite element application Abaqus 2016 was used for all of the analyses. The analyses conclude that the seasonal temperature variations have a significant in influence on the structural behaviour of arch dams in colder climates. As the water temperature do not go below 0 °C, cold winters can have a major effect on arch dams in regards to deformation and cracking., I norra Sverige kan dammar vara utsatta för temperaturvariationer på upp emot 60 - 70 °C mellan sommar och vinter. Detta resulterar ofta i sprickbildning orsakad av att betongen expanderar och kontraherar vid temperaturökning respektive minskning. Detta arbete är del av ett initiativ från ICOLD-kommitten ”Computational Aspects of Dam Analysis" med mål att ta fram en lämplig beräkningsmetodik för modellering av betongvalvdammar och undersöka hur temperaturvariationer över året inverkar på sprickbildning.

The aim of this study is to investigate how Fluid-Structure interaction may be included in numerical earthquake analyses of dams. The basis for this project is theme A from ICOLDs 12th international benchmark workshop on numerical analysis of dams, which was held in October 2013. The focus of theme A was on how to account for fluid structure interaction in numerical earthquake analyses of dams. In this study, parametric numerical analyses have been performed where the purpose was to isolate some important parameters and investigate how these influence the results in seismic analyses of dams. These analyses were performed through the use of the finite element methodare the choice of Rayleigh damping parameters, reservoir boundaries and wave absorption in the foundation-reservoir interface. The use of acoustic elements has proven to be a powerful approach for FSI analyses of adam-reservoir-computation time, while allowing for more advanced features such as bottom absorption and non- be a challenging task, where it has a significant impact on the results. The method proposed by Spears and Jensen has a physical meaning in the sense that this method excites the same e ective mass for the Rayleigh damped case as for the modal damped case. If a constant modal damping is desired or prescribed in a standard, this method provides a reasonable and sound method to choose the Rayleigh damping parameters for a complex structure. A more straightforward method is to choose the two frequencies in such a way that the span between the frequencies covers about 80% of the e ective mass. The choice of reservoir boundary conditionsparameter showed to be the one that least a ected the results in the time-history analysis. results and this coe cient should be used carefully., QC 20190729

The aim of this study is to investigate how Fluid-Structure interaction may be included in numerical earthquake analyses of dams. The basis for this project is theme A from ICOLDs 12th international benchmark workshop on numerical analysis of dams, which was held in October 2013. The focus of theme A was on how to account for fluid structure interaction in numerical earthquake analyses of dams. In this study, parametric numerical analyses have been performed where the purpose was to isolate some important parameters and investigate how these influence the results in seismic analyses of dams. These analyses were performed through the use of the finite element methodare the choice of Rayleigh damping parameters, reservoir boundaries and wave absorption in the foundation-reservoir interface. The use of acoustic elements has proven to be a powerful approach for FSI analyses of adam-reservoir-computation time, while allowing for more advanced features such as bottom absorption and non- be a challenging task, where it has a significant impact on the results. The method proposed by Spears and Jensen has a physical meaning in the sense that this method excites the same e ective mass for the Rayleigh damped case as for the modal damped case. If a constant modal damping is desired or prescribed in a standard, this method provides a reasonable and sound method to choose the Rayleigh damping parameters for a complex structure. A more straightforward method is to choose the two frequencies in such a way that the span between the frequencies covers about 80% of the e ective mass. The choice of reservoir boundary conditionsparameter showed to be the one that least a ected the results in the time-history analysis. results and this coe cient should be used carefully., QC 20190729

The aim of this study is to investigate how Fluid-Structure interaction may beincluded in numerical earthquake analyses of dams. The basis for this project is theme Afrom ICOLDs 12th international benchmark workshop on numerical analysis of dams,which was held in October 2013. The focus of theme A was on how to account for fluidstructure interaction in numerical earthquake analyses of dams. In this study, parametricnumerical analyses have been performed where the purpose was to isolate someimportant parameters and investigate how these influence the results in seismic analysesof dams. These analyses were performed through the use of the finite element methodare the choice of Rayleigh damping parameters, reservoir boundaries and waveabsorption in the foundation-reservoir interface. The use of acoustic elements has proven to be a powerful approach for FSI analyses of adam-reservoir-computation time, while allowing for more advanced features such as bottom absorptionand non-be a challenging task, where it has a significant impact on the results. The methodproposed by Spears and Jensen has a physical meaning in the sense that this methodexcites the same e ective mass for the Rayleigh damped case as for the modal dampedcase. If a constant modal damping is desired or prescribed in a standard, this methodprovides a reasonable and sound method to choose the Rayleigh damping parameters fora complex structure. A more straightforward method is to choose the two frequencies insuch a way that the span between the frequencies covers about 80% of the e ective mass.The choice of reservoir boundary conditionsparameter showed to be the one that least a ected the results in the time-history analysis.results and this coe cient should be used carefully., QC 20160121

The aim of this study is to investigate how Fluid-Structure interaction may be included in numerical earthquake analyses of dams. The basis for this project is theme A from ICOLDs 12th international benchmark workshop on numerical analysis of dams, which was held in October 2013. The focus of theme A was on how to account for fluid structure interaction in numerical earthquake analyses of dams. In this study, parametric numerical analyses have been performed where the purpose was to isolate some important parameters and investigate how these influence the results in seismic analyses of dams. These analyses were performed through the use of the finite element methodare the choice of Rayleigh damping parameters, reservoir boundaries and wave absorption in the foundation-reservoir interface. The use of acoustic elements has proven to be a powerful approach for FSI analyses of adam-reservoir-computation time, while allowing for more advanced features such as bottom absorption and non- be a challenging task, where it has a significant impact on the results. The method proposed by Spears and Jensen has a physical meaning in the sense that this method excites the same e ective mass for the Rayleigh damped case as for the modal damped case. If a constant modal damping is desired or prescribed in a standard, this method provides a reasonable and sound method to choose the Rayleigh damping parameters for a complex structure. A more straightforward method is to choose the two frequencies in such a way that the span between the frequencies covers about 80% of the e ective mass. The choice of reservoir boundary conditionsparameter showed to be the one that least a ected the results in the time-history analysis. results and this coe cient should be used carefully., QC 20190729

The aim of this study is to investigate how Fluid-Structure interaction may be included in numerical earthquake analyses of dams. The basis for this project is theme A from ICOLDs 12th international benchmark workshop on numerical analysis of dams, which was held in October 2013. The focus of theme A was on how to account for fluid structure interaction in numerical earthquake analyses of dams. In this study, parametric numerical analyses have been performed where the purpose was to isolate some important parameters and investigate how these influence the results in seismic analyses of dams. These analyses were performed through the use of the finite element methodare the choice of Rayleigh damping parameters, reservoir boundaries and wave absorption in the foundation-reservoir interface. The use of acoustic elements has proven to be a powerful approach for FSI analyses of adam-reservoir-computation time, while allowing for more advanced features such as bottom absorption and non- be a challenging task, where it has a significant impact on the results. The method proposed by Spears and Jensen has a physical meaning in the sense that this method excites the same e ective mass for the Rayleigh damped case as for the modal damped case. If a constant modal damping is desired or prescribed in a standard, this method provides a reasonable and sound method to choose the Rayleigh damping parameters for a complex structure. A more straightforward method is to choose the two frequencies in such a way that the span between the frequencies covers about 80% of the e ective mass. The choice of reservoir boundary conditionsparameter showed to be the one that least a ected the results in the time-history analysis. results and this coe cient should be used carefully., QC 20190729

The aim of this study is to investigate how Fluid-Structure interaction may be included in numerical earthquake analyses of dams. The basis for this project is theme A from ICOLDs 12th international benchmark workshop on numerical analysis of dams, which was held in October 2013. The focus of theme A was on how to account for fluid structure interaction in numerical earthquake analyses of dams. In this study, parametric numerical analyses have been performed where the purpose was to isolate some important parameters and investigate how these influence the results in seismic analyses of dams. These analyses were performed through the use of the finite element methodare the choice of Rayleigh damping parameters, reservoir boundaries and wave absorption in the foundation-reservoir interface. The use of acoustic elements has proven to be a powerful approach for FSI analyses of adam-reservoir-computation time, while allowing for more advanced features such as bottom absorption and non- be a challenging task, where it has a significant impact on the results. The method proposed by Spears and Jensen has a physical meaning in the sense that this method excites the same e ective mass for the Rayleigh damped case as for the modal damped case. If a constant modal damping is desired or prescribed in a standard, this method provides a reasonable and sound method to choose the Rayleigh damping parameters for a complex structure. A more straightforward method is to choose the two frequencies in such a way that the span between the frequencies covers about 80% of the e ective mass. The choice of reservoir boundary conditionsparameter showed to be the one that least a ected the results in the time-history analysis. results and this coe cient should be used carefully., QC 20190729

The aim of this study is to investigate how Fluid-Structure interaction is included in numerical earthquake analyses of dams. The base for this project is theme A from the 12th international benchmark workshop on numerical analysis of dams, which was held in October 2013. The focus of theme A was how to account for the fluid structure interaction in numerical earthquake analyses of dams. To highlight how engineers and researchers include this interaction in their analysis, a literature review of the modeling choices and conclusions from all participants are included. Since the workshop contains participants from seven countries, this review aims to describe of how this analysis is carried out in practice. Further, parametric numerical analyses are performed in this study, where the purpose is to isolate some important parameters and investigate how these influence the results in seismic analyses of dams. These analyses were performed through the use of the finite element method. The geometric model from the benchmark workshop was used and analysed with the commercial software Abaqus. The studied parameters are the choice of fluid element, Rayleigh damping parameters, reservoir boundaries and wave absorption in the foundation-reservoir interface. The water has a major effect on a dam's seismic behaviour and should be included in the analysis. The added mass approach gives similar results compared with a more sophisticated method. This simplified approach could be used in engineering purpose where the time is limited and the accuracy is of lesser importance, since the calculated stresses are conservative. Using acoustic finite elements provides a reasonable computation time, while also allowing for more advanced features, such as bottom absorption and non-reflecting boundaries The definition of Rayleigh damping has proven to be a very challenging task, especially as it has a large impact on the results. The choice of boundary conditions for the back end of the reservo, Syftet med denna studie är att undersöka hur fluid-struktur interaktion inkluderas i numeriska jordbävningsanalyser av dammar. Detta ämne var ett av de teman som behandlades vid den 12:e internationella benchmark-workshopen för numerisk analys av dammar som hölls i oktober 2014 i Graz, österike. För att visa hur ingenjörer och forskare tar hänsyn till denna interaktion har en litteraturstudie på bidragen till workshopen genomförts. Då workshopen lockade deltagare från universitet och konstruktionsfirmor från sju länder, är målet att kunna beskriva hur jordbävningsanalyser av dammar utförs i praktiken. Dessutom har numeriska parameterstudier genomförts, med syfte att isolera enskilda parametrars inverkan vid seismiska anslyser av dammar. Analyserna har utförts med finita elementmetoden och analyserna är utförda med den geometriska modellen som användes i workshopen. Alla analyser har utförts i programmet Abaqus. De analyserade parametrarna är, val av fluid-element, Rayleigh dämpningsparametrar, randvillkor för reservoaren samt tryckvågsabsorption i gränsytan mellan reservoar och berg. Vattnet har en stor inverkan på dammen och de hydrodynamiska effekterna bör inkluderas vid en jordbävningsanalys. Metoden med impulsiv massa ger liknande resultat jämfört med mer sofistikerade metoder. Denna enklare metod kan användas i samanhang där beräknings och modelleringstid är begränsad och noggrannhet är av mindre intresse så länge resultaten är konservativa. För tillämpningar där noggrannheten är viktigare kan akustiska element användas för att beskriva vattnet. De akustiska element ger möjligheter för mer sofistikerade analyser där t.ex. vågabsorption och icke reflekterande gränser kan beaktas. Att välja Rayleigh dämpning visade sig var en väldigt utmanande uppgift, där valet hade stor påverkan på resultaten. Valet av randvillkor för reservoarens bortre ände var den parameter som hade minst påverkan på resultaten. Det konservativa valet är att välja en ''fixed'' gräns

The aim of this study is to investigate how Fluid-Structure interaction is included in numerical earthquake analyses of dams. The base for this project is theme A from the 12th international benchmark workshop on numerical analysis of dams, which was held in October 2013. The focus of theme A was how to account for the fluid structure interaction in numerical earthquake analyses of dams. To highlight how engineers and researchers include this interaction in their analysis, a literature review of the modeling choices and conclusions from all participants are included. Since the workshop contains participants from seven countries, this review aims to describe of how this analysis is carried out in practice. Further, parametric numerical analyses are performed in this study, where the purpose is to isolate some important parameters and investigate how these influence the results in seismic analyses of dams. These analyses were performed through the use of the finite element method. The geometric model from the benchmark workshop was used and analysed with the commercial software Abaqus. The studied parameters are the choice of fluid element, Rayleigh damping parameters, reservoir boundaries and wave absorption in the foundation-reservoir interface. The water has a major effect on a dam's seismic behaviour and should be included in the analysis. The added mass approach gives similar results compared with a more sophisticated method. This simplified approach could be used in engineering purpose where the time is limited and the accuracy is of lesser importance, since the calculated stresses are conservative. Using acoustic finite elements provides a reasonable computation time, while also allowing for more advanced features, such as bottom absorption and non-reflecting boundaries The definition of Rayleigh damping has proven to be a very challenging task, especially as it has a large impact on the results. The choice of boundary conditions for the back end of the reservo, Syftet med denna studie är att undersöka hur fluid-struktur interaktion inkluderas i numeriska jordbävningsanalyser av dammar. Detta ämne var ett av de teman som behandlades vid den 12:e internationella benchmark-workshopen för numerisk analys av dammar som hölls i oktober 2014 i Graz, österike. För att visa hur ingenjörer och forskare tar hänsyn till denna interaktion har en litteraturstudie på bidragen till workshopen genomförts. Då workshopen lockade deltagare från universitet och konstruktionsfirmor från sju länder, är målet att kunna beskriva hur jordbävningsanalyser av dammar utförs i praktiken. Dessutom har numeriska parameterstudier genomförts, med syfte att isolera enskilda parametrars inverkan vid seismiska anslyser av dammar. Analyserna har utförts med finita elementmetoden och analyserna är utförda med den geometriska modellen som användes i workshopen. Alla analyser har utförts i programmet Abaqus. De analyserade parametrarna är, val av fluid-element, Rayleigh dämpningsparametrar, randvillkor för reservoaren samt tryckvågsabsorption i gränsytan mellan reservoar och berg. Vattnet har en stor inverkan på dammen och de hydrodynamiska effekterna bör inkluderas vid en jordbävningsanalys. Metoden med impulsiv massa ger liknande resultat jämfört med mer sofistikerade metoder. Denna enklare metod kan användas i samanhang där beräknings och modelleringstid är begränsad och noggrannhet är av mindre intresse så länge resultaten är konservativa. För tillämpningar där noggrannheten är viktigare kan akustiska element användas för att beskriva vattnet. De akustiska element ger möjligheter för mer sofistikerade analyser där t.ex. vågabsorption och icke reflekterande gränser kan beaktas. Att välja Rayleigh dämpning visade sig var en väldigt utmanande uppgift, där valet hade stor påverkan på resultaten. Valet av randvillkor för reservoarens bortre ände var den parameter som hade minst påverkan på resultaten. Det konservativa valet är att välja en ''fixed'' gräns