The Experts below are selected from a list of 180 Experts worldwide ranked by ideXlab platform

Ramazan Livaoglu - One of the best experts on this subject based on the ideXlab platform.

  • Soil interaction effects on sloshing response of the Elevated Tanks
    Geomechanics and Engineering, 2013
    Co-Authors: Ramazan Livaoglu
    Abstract:

    The aim of this paper is to investigate how the soil-structure interaction affects sloshing response of the Elevated Tanks. For this purpose, the Elevated Tanks with two different types of supporting systems which are built on six different soil profiles are analyzed for both embedded and surface foundation cases. Thus, considering these six different profiles described in well-known earthquake codes as supporting medium, a series of transient analysis have been performed to assess the effect of both fluid sloshing and soil-structure interaction (SSI). Fluid-Elevated Tank-Soil/Foundation systems are modeled with the finite element (FE) technique. In these models fluid-structure interaction is taken into account by implementing Lagrangian fluid FE approximation into the general purpose structural analysis computer code ANSYS. A 3-D FE model with viscous boundary is used in the analyses of Elevated Tanks-soil/foundation interaction. Formed models are analyzed for embedment and no embedment cases. Finally results from analyses showed that the soil-structure interaction and the structural properties of supporting system for the Elevated Tanks affected the sloshing response of the fluid inside the vessel.

  • Effect of foundation embedment on seismic behavior of Elevated Tanks considering fluid-structure-soil interaction
    Soil Dynamics and Earthquake Engineering, 2007
    Co-Authors: Ramazan Livaoglu, Adem Dogangun
    Abstract:

    This paper investigates the effects of foundation embedment on the seismic behavior of fluid-Elevated Tank-foundation–soil system with a structural frame supporting the fluid containing Tank. Six different soil types defined in the well-known seismic codes were considered. Both the sloshing effects of the fluid and soil-structure interaction of the Elevated Tanks located on these six different soils were included in the analyses. Fluid-Elevated Tank-foundation–soil systems were modeled with the finite element (FE) technique. The fluid-structure interaction was taken into account using Lagrangian fluid FE approximation implemented in the general purpose structural analysis computer program, ANSYS. FE model with viscous boundary was used to include Elevated Tank-foundation–soil interaction effects. The models were analyzed for the foundations with and without embedment. It was found that the Tank roof displacements were affected significantly by the embedment in soft soil, however, this effect was smaller for stiff soil types. Except for soft soil types, embedment did not affect the other response parameters, such as sloshing displacement, of the systems considered in this study.

  • Seismic behaviour of cylindrical Elevated Tanks with a frame supporting system on various subsoil
    Indian Journal of Engineering and Materials Sciences, 2007
    Co-Authors: Ramazan Livaoglu, Adem Dogangun
    Abstract:

    The seismic responses of an Elevated Tank with a frame supporting system on various subsoils are investigated. The finite element method is used for the modelling of the Elevated Tank and subsoil system. Fixed-base and elastic media assumptions are made for subsoil. The Tank fluid has been modelled as lumped masses such as impulsive and convective masses proposed by Housner. An added mass approach is used for fluid-structure interaction by representing both the impulsive mass and the convective mass. For estimating the seismic response of Elevated Tanks, response spectrum analysis with mode superposition is used. The results obtained from modelling the Elevated Tanks on a fixed base and on an elastic medium are compared. It has been observed that the seismic response of the Elevated Tank is altered significantly depending on the properties of the subsoil. The soil-structure interaction especially affects the impulsive modes and lateral displacement of Elevated Tanks rather than the torsional modes. It is proposed that the coupling effect for perpendicular directions in the axisymmetrical plan geometry should be considered in the seismic design of the Elevated Tanks.

  • seismic evaluation of fluid Elevated Tank foundation soil systems in frequency domain
    Structural Engineering and Mechanics, 2005
    Co-Authors: Ramazan Livaoglu, A Dogangun
    Abstract:

    An efficient methodology is presented to evaluate the seismic behavior of a Fluid-Elevated Tank-Foundation/Soil system taking the embedment effects into accounts. The frequency-dependent cone model is used for considering the Elevated Tank-foundation/soil interaction and the equivalent spring-mass model given in the Eurocode-8 is used for fluid-Elevated Tank interaction. Both models are combined to obtain the seismic response of the systems considering the sloshing effects of the fluid and frequency-dependent properties of soil. The analysis is carried out in the frequency domain with a modal analysis procedure. The presented methodology with less computational efforts takes account of; the soil and fluid interactions, the material and radiation damping effects of the elastic half-space, and the embedment effects. Some conclusions may be summarized as follows; the sloshing response is not practically affected by the change of properties in stiff soil such as S1 and S2 and embedment but affected in soft soil. On the other hand, these responses are not affected by embedment in stiff soils but affected in soft soils.

  • Seismic evaluation of fluid-Elevated Tank-foundation/soil systems in frequency domain
    Structural Engineering and Mechanics, 2005
    Co-Authors: Ramazan Livaoglu, A Dogangun
    Abstract:

    An efficient methodology is presented to evaluate the seismic behavior of a Fluid-Elevated Tank-Foundation/Soil system taking the embedment effects into accounts. The frequency-dependent cone model is used for considering the Elevated Tank-foundation/soil interaction and the equivalent spring-mass model given in the Eurocode-8 is used for fluid-Elevated Tank interaction. Both models are combined to obtain the seismic response of the systems considering the sloshing effects of the fluid and frequency-dependent properties of soil. The analysis is carried out in the frequency domain with a modal analysis procedure. The presented methodology with less computational efforts takes account of; the soil and fluid interactions, the material and radiation damping effects of the elastic half-space, and the embedment effects. Some conclusions may be summarized as follows; the sloshing response is not practically affected by the change of properties in stiff soil such as S1 and S2 and embedment but affected in soft soil. On the other hand, these responses are not affected by embedment in stiff soils but affected in soft soils.

A Dogangun - One of the best experts on this subject based on the ideXlab platform.

  • seismic evaluation of fluid Elevated Tank foundation soil systems in frequency domain
    Structural Engineering and Mechanics, 2005
    Co-Authors: Ramazan Livaoglu, A Dogangun
    Abstract:

    An efficient methodology is presented to evaluate the seismic behavior of a Fluid-Elevated Tank-Foundation/Soil system taking the embedment effects into accounts. The frequency-dependent cone model is used for considering the Elevated Tank-foundation/soil interaction and the equivalent spring-mass model given in the Eurocode-8 is used for fluid-Elevated Tank interaction. Both models are combined to obtain the seismic response of the systems considering the sloshing effects of the fluid and frequency-dependent properties of soil. The analysis is carried out in the frequency domain with a modal analysis procedure. The presented methodology with less computational efforts takes account of; the soil and fluid interactions, the material and radiation damping effects of the elastic half-space, and the embedment effects. Some conclusions may be summarized as follows; the sloshing response is not practically affected by the change of properties in stiff soil such as S1 and S2 and embedment but affected in soft soil. On the other hand, these responses are not affected by embedment in stiff soils but affected in soft soils.

  • Seismic evaluation of fluid-Elevated Tank-foundation/soil systems in frequency domain
    Structural Engineering and Mechanics, 2005
    Co-Authors: Ramazan Livaoglu, A Dogangun
    Abstract:

    An efficient methodology is presented to evaluate the seismic behavior of a Fluid-Elevated Tank-Foundation/Soil system taking the embedment effects into accounts. The frequency-dependent cone model is used for considering the Elevated Tank-foundation/soil interaction and the equivalent spring-mass model given in the Eurocode-8 is used for fluid-Elevated Tank interaction. Both models are combined to obtain the seismic response of the systems considering the sloshing effects of the fluid and frequency-dependent properties of soil. The analysis is carried out in the frequency domain with a modal analysis procedure. The presented methodology with less computational efforts takes account of; the soil and fluid interactions, the material and radiation damping effects of the elastic half-space, and the embedment effects. Some conclusions may be summarized as follows; the sloshing response is not practically affected by the change of properties in stiff soil such as S1 and S2 and embedment but affected in soft soil. On the other hand, these responses are not affected by embedment in stiff soils but affected in soft soils.

Enrico Creaco - One of the best experts on this subject based on the ideXlab platform.

  • Using Additional Time Slots for Improving Pump Control Optimization Based on Trigger Levels
    Water Resources Management, 2019
    Co-Authors: Claudia Quintiliani, Enrico Creaco
    Abstract:

    This paper presents a new methodology for optimizing the operation of pumps supplying water from a low source to an Elevated Tank in water distribution systems (WDSs). It is based on the use of the on/off trigger level technique for each pump present in the pumping station. The novelty of the methodology consists of the addition of time slots for the optimization of the trigger levels. These slots are created at the end of each energy tariff period, to drive the Tank level to the highest and lowest points at the beginning and at the end of the peak, respectively. As a result, pumps are led to work more and less during low and high tariff periods, respectively, yielding reductions in energy costs. In the applications, the methodology was introduced within a multi-objective optimization framework, searching for solutions in the trade-off between daily average energy cost and daily average number of pump switches, representative of the stressing conditions for the system. The methodology was applied to case studies with single and multiple pumps, using realistic demand patterns, and was compared with other trigger levels-based methodologies in the scientific literature. The results proved its benefits, in yielding solutions with reduced number of pump switches for prefixed values of energy cost. This is more evident when the operation of three pumps must be optimized. In an explicative example with three operating pumps, for an energy cost around 6000 €/day, the newly proposed methodology leads to a number of pump switches between 17% and 33% lower than the results obtained with the methods considered for comparison.

Adem Dogangun - One of the best experts on this subject based on the ideXlab platform.

  • Effect of foundation embedment on seismic behavior of Elevated Tanks considering fluid-structure-soil interaction
    Soil Dynamics and Earthquake Engineering, 2007
    Co-Authors: Ramazan Livaoglu, Adem Dogangun
    Abstract:

    This paper investigates the effects of foundation embedment on the seismic behavior of fluid-Elevated Tank-foundation–soil system with a structural frame supporting the fluid containing Tank. Six different soil types defined in the well-known seismic codes were considered. Both the sloshing effects of the fluid and soil-structure interaction of the Elevated Tanks located on these six different soils were included in the analyses. Fluid-Elevated Tank-foundation–soil systems were modeled with the finite element (FE) technique. The fluid-structure interaction was taken into account using Lagrangian fluid FE approximation implemented in the general purpose structural analysis computer program, ANSYS. FE model with viscous boundary was used to include Elevated Tank-foundation–soil interaction effects. The models were analyzed for the foundations with and without embedment. It was found that the Tank roof displacements were affected significantly by the embedment in soft soil, however, this effect was smaller for stiff soil types. Except for soft soil types, embedment did not affect the other response parameters, such as sloshing displacement, of the systems considered in this study.

  • Seismic behaviour of cylindrical Elevated Tanks with a frame supporting system on various subsoil
    Indian Journal of Engineering and Materials Sciences, 2007
    Co-Authors: Ramazan Livaoglu, Adem Dogangun
    Abstract:

    The seismic responses of an Elevated Tank with a frame supporting system on various subsoils are investigated. The finite element method is used for the modelling of the Elevated Tank and subsoil system. Fixed-base and elastic media assumptions are made for subsoil. The Tank fluid has been modelled as lumped masses such as impulsive and convective masses proposed by Housner. An added mass approach is used for fluid-structure interaction by representing both the impulsive mass and the convective mass. For estimating the seismic response of Elevated Tanks, response spectrum analysis with mode superposition is used. The results obtained from modelling the Elevated Tanks on a fixed base and on an elastic medium are compared. It has been observed that the seismic response of the Elevated Tank is altered significantly depending on the properties of the subsoil. The soil-structure interaction especially affects the impulsive modes and lateral displacement of Elevated Tanks rather than the torsional modes. It is proposed that the coupling effect for perpendicular directions in the axisymmetrical plan geometry should be considered in the seismic design of the Elevated Tanks.

A N Timokha - One of the best experts on this subject based on the ideXlab platform.