The Experts below are selected from a list of 156 Experts worldwide ranked by ideXlab platform
George Karagiannakis - One of the best experts on this subject based on the ideXlab platform.
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Seismic Assessment of Pipe Racks Accounting for Soil-Structure Interaction
International Journal of Steel Structures, 2020Co-Authors: Luigi Di Sarno, George KaragiannakisAbstract:The research on the seismic assessment of Pipe Racks accounting for coupling and soil-structure interaction effects is still scarce. Common industrial practice overlooks critical design aspects due to the insufficiency of current codes that might result in over-conservative or unsafe design. This work addresses the nonlinear analysis of a petrochemical plant steel Pipe rack accounting for dynamic interaction with horizontal vessels and Pipelines. Soil-structure interaction was evaluated both on Pipe rack and Pipelines in terms of interstorey-drift ratio and stress–strain response. An attempt was made for correlating the ratio with piping strain to make comparisons with common acceptance criteria for building structures, since code provisions do not address currently limit state design concept for Pipe Racks. Additionally, seismic fragility curves along with 95% confidence intervals were evaluated for different intensity measures and were used as a tool to demonstrate that the soil deformability could act as an isolation mechanism for Pipelines. The increase of Pipe rack displacements was an additional impact of soil, though, it was not as much profound as on the seismic response of the Pipelines. The detailed structural assessment through extensive nonlinear dynamic analyses demonstrated that the return period of exceedance of Pipe rack and Pipelines limit state, considering the median spectral acceleration as a measure, occurred 1.84 and 2.64 greater than the design one, and this might be an indication that the performance-based concept should be applied for Pipe rack systems to achieve a safe, risk-consistent among structural and nonstructural members and cost-effective design.
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On the seismic fragility of Pipe rack—piping systems considering soil–structure interaction
Bulletin of Earthquake Engineering, 2020Co-Authors: Luigi Di Sarno, George KaragiannakisAbstract:Piping systems constitute the most vulnerable component in down- and mid-stream facilities posing immediate threat to human lives, communities financial robustness and environment. Pipe Racks present several mechanical and geometrical idiosyncrasies compared to common buildings and the seismic response is governed by the Pipework layout. Important design requirements e.g. dynamic interaction between Pipelines and supporting structure are commonly overlooked during Pipe Racks design process and uncertainties relevant to modelling of soil or seismic input are not quantified. In the present work, after reviewing the technical literature and codes, a 3D RC rack was used as a testbed and analysed as coupled and decoupled with a non-seismic code conforming piping system accounting for soil–structure interaction. Incremental dynamic analysis was adopted as an assessment methodology for deriving fragility curves considering ground motions in near- and far-field conditions. It was deduced that the modelling (boundary conditions of Pipes) was the most considerable uncertainty since it increased the probability of collapse limit state of structural members from 0 to 59%. It was also demonstrated that soil deformability as well as source conditions altered considerably the dispersion of intensity measure conditional on engineering demand parameter of structural and nonstructural members. The results may be another indication that code provisions should be more normative regarding industrial Pipe Racks.
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Investigation of the Seismic Risk of Industrial Pipe Rack - Piping Systems Accounting for Soil-Structure Interaction
Volume 5: High-Pressure Technology; Rudy Scavuzzo Student Paper Symposium and 27th Annual Student Paper Competition; ASME Nondestructive Evaluation Di, 2019Co-Authors: George Karagiannakis, Luigi Di SarnoAbstract:Abstract Earthquake events have shown that industrial Pipe Racks lack of a completed design framework that encompasses contemporarily a number of uncertainties such as modelling, seismic action, design and analysis procedures as well as soil conditions. That being said, the seismic behaviour of piping systems has not been assessed up to par recognizing the potential effects of nonbuilding – nonstructural components interaction as well as soil conditions that constitute a decisive parameter particularly for structures that lie on alluvial deposits. In the present work, after reviewing European and American standards and technical literature upon design parameters, the seismic reliability analysis of two Pipe rack – piping systems in decoupled and coupled case considering near- and far-field records as well as soil deformability is addressed. As it is illustrated, the classic nonlinear static analysis may overestimate the resistance of Racks, common limit states of interstorey drift ratio cannot be applied and the behaviour factor selection may be unjustifiable. Also, soil-structure interaction affects detrimentally the response both of rack and piping system as depicted by the fragility functions.
Luigi Di Sarno - One of the best experts on this subject based on the ideXlab platform.
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Seismic Assessment of Pipe Racks Accounting for Soil-Structure Interaction
International Journal of Steel Structures, 2020Co-Authors: Luigi Di Sarno, George KaragiannakisAbstract:The research on the seismic assessment of Pipe Racks accounting for coupling and soil-structure interaction effects is still scarce. Common industrial practice overlooks critical design aspects due to the insufficiency of current codes that might result in over-conservative or unsafe design. This work addresses the nonlinear analysis of a petrochemical plant steel Pipe rack accounting for dynamic interaction with horizontal vessels and Pipelines. Soil-structure interaction was evaluated both on Pipe rack and Pipelines in terms of interstorey-drift ratio and stress–strain response. An attempt was made for correlating the ratio with piping strain to make comparisons with common acceptance criteria for building structures, since code provisions do not address currently limit state design concept for Pipe Racks. Additionally, seismic fragility curves along with 95% confidence intervals were evaluated for different intensity measures and were used as a tool to demonstrate that the soil deformability could act as an isolation mechanism for Pipelines. The increase of Pipe rack displacements was an additional impact of soil, though, it was not as much profound as on the seismic response of the Pipelines. The detailed structural assessment through extensive nonlinear dynamic analyses demonstrated that the return period of exceedance of Pipe rack and Pipelines limit state, considering the median spectral acceleration as a measure, occurred 1.84 and 2.64 greater than the design one, and this might be an indication that the performance-based concept should be applied for Pipe rack systems to achieve a safe, risk-consistent among structural and nonstructural members and cost-effective design.
-
On the seismic fragility of Pipe rack—piping systems considering soil–structure interaction
Bulletin of Earthquake Engineering, 2020Co-Authors: Luigi Di Sarno, George KaragiannakisAbstract:Piping systems constitute the most vulnerable component in down- and mid-stream facilities posing immediate threat to human lives, communities financial robustness and environment. Pipe Racks present several mechanical and geometrical idiosyncrasies compared to common buildings and the seismic response is governed by the Pipework layout. Important design requirements e.g. dynamic interaction between Pipelines and supporting structure are commonly overlooked during Pipe Racks design process and uncertainties relevant to modelling of soil or seismic input are not quantified. In the present work, after reviewing the technical literature and codes, a 3D RC rack was used as a testbed and analysed as coupled and decoupled with a non-seismic code conforming piping system accounting for soil–structure interaction. Incremental dynamic analysis was adopted as an assessment methodology for deriving fragility curves considering ground motions in near- and far-field conditions. It was deduced that the modelling (boundary conditions of Pipes) was the most considerable uncertainty since it increased the probability of collapse limit state of structural members from 0 to 59%. It was also demonstrated that soil deformability as well as source conditions altered considerably the dispersion of intensity measure conditional on engineering demand parameter of structural and nonstructural members. The results may be another indication that code provisions should be more normative regarding industrial Pipe Racks.
-
Investigation of the Seismic Risk of Industrial Pipe Rack - Piping Systems Accounting for Soil-Structure Interaction
Volume 5: High-Pressure Technology; Rudy Scavuzzo Student Paper Symposium and 27th Annual Student Paper Competition; ASME Nondestructive Evaluation Di, 2019Co-Authors: George Karagiannakis, Luigi Di SarnoAbstract:Abstract Earthquake events have shown that industrial Pipe Racks lack of a completed design framework that encompasses contemporarily a number of uncertainties such as modelling, seismic action, design and analysis procedures as well as soil conditions. That being said, the seismic behaviour of piping systems has not been assessed up to par recognizing the potential effects of nonbuilding – nonstructural components interaction as well as soil conditions that constitute a decisive parameter particularly for structures that lie on alluvial deposits. In the present work, after reviewing European and American standards and technical literature upon design parameters, the seismic reliability analysis of two Pipe rack – piping systems in decoupled and coupled case considering near- and far-field records as well as soil deformability is addressed. As it is illustrated, the classic nonlinear static analysis may overestimate the resistance of Racks, common limit states of interstorey drift ratio cannot be applied and the behaviour factor selection may be unjustifiable. Also, soil-structure interaction affects detrimentally the response both of rack and piping system as depicted by the fragility functions.
Høgåsen, Stian Lunde - One of the best experts on this subject based on the ideXlab platform.
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Alternativ etableringsmåte for modell av “Onshore Steel Outfitting Structure”
Norges teknisk-naturvitenskapelige universitet Fakultet for ingeniørvitenskap og teknologi Institutt for konstruksjonsteknikk, 2010Co-Authors: Høgåsen, Stian LundeAbstract:Pipe Racks are steel frame structures used to support piping, cables, trays etc. at oil and gas facilities onshore and offshore. Pipe Racks may vary in design but thefundamental principals are the same. The geometry is therefore suitable for automate design.The main goal of this thesis was to establish a geometric foundation for onshorePipe rack implementation in knowledge based engineering (KBE) design.Loadsand geometry is based on models and design briefs from the onshore Ormen Langefacility at Nyhamna, Norway and Eurocodes for steel structures.Four heights, three widths, three lengths and two support conditions are combinedto make the models presented in this work. These parameters are chosen basedon observations of existing onshore Pipe Racks and specifications from the provideddesign briefs. Combined with 11 load cases these parameters results in a total of 36 analyses.All structures have been designed according to ultimate limit state (ULS), accidental limit state (ALS) and service ability limit state (SLS) design codes, where it is placed emphasis on ULS design codes.The results from this work is found in appendix D.Profile types have been chosen based on both geometric properties and capacity,where the geometric properties are governed by a design hierarchy.All calculations and assumptions are based on the fact that this is an early stagedesign. Results from the work carried out in this assignment is hence not a finalproduct. More analysis needs to be carried out and more design alternatives shouldbe provided before a final KBE product can be made.
Stian Lunde Høgåsen - One of the best experts on this subject based on the ideXlab platform.
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Variant Creation of Onshore Steel Outfitting Structures
2010Co-Authors: Stian Lunde HøgåsenAbstract:Pipe Racks are steel frame structures used to support piping, cables, trays etc. at oil and gas facilities onshore and offshore. Pipe Racks may vary in design but thefundamental principals are the same. The geometry is therefore suitable for automate design. The main goal of this thesis was to establish a geometric foundation for onshorePipe rack implementation in knowledge based engineering (KBE) design.Loadsand geometry is based on models and design briefs from the onshore Ormen Langefacility at Nyhamna, Norway and Eurocodes for steel structures. Four heights, three widths, three lengths and two support conditions are combinedto make the models presented in this work. These parameters are chosen basedon observations of existing onshore Pipe Racks and specifications from the provideddesign briefs. Combined with 11 load cases these parameters results in a total of 36 analyses. All structures have been designed according to ultimate limit state (ULS), accidental limit state (ALS) and service ability limit state (SLS) design codes, where it is placed emphasis on ULS design codes. The results from this work is found in appendix D. Profile types have been chosen based on both geometric properties and capacity,where the geometric properties are governed by a design hierarchy. All calculations and assumptions are based on the fact that this is an early stagedesign. Results from the work carried out in this assignment is hence not a finalproduct. More analysis needs to be carried out and more design alternatives shouldbe provided before a final KBE product can be made.
A. N. Shankar - One of the best experts on this subject based on the ideXlab platform.
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Optimization of Piperack for Sea Transportation Condition
Imperial journal of interdisciplinary research, 2017Co-Authors: K. Naga Bharathi, A. N. ShankarAbstract:: Pipe Racks are framed structures that supports Pipes and auxiliary equipment in the process areas of industrial plants. Pre-Assembled Pipe-rack is used to overcome the issues like remoteness of site, labour shortage, and tight project schedule. Pre-assembled modules (PAM) building process employs the fabrication of permanent structural steel framework with temporary foundations, and it is used for maximizing the transfer of man hours off site and reducing overall construction time. This paper provides the description of the structural analysis of the framework under sea transportation to obtain the stresses and deflection of the structure. Module will be transported to the in-place site location. The global design analysis and design of an offshore module of 4m*20m*4.6m length, width and height respectively is considered to check the sea transportation analysis feasibility of the module in all load cases and design aspects. The structural analysis is performed considering in-place as the first stage of process, sea transportation was the second stage, considering corresponding transportation loads then the optimization process is to be carried out for cost effectiveness and proper utilization of the material properties Conclusions are drawn based on the results of the transportation analysis of the module based on various design transportation loads with a Code check and deflection check within permissible limits for a different transportation analysis condition.