Seismic performance of existing liquid pentane storage tanks located in a tank farm in Turkey Kocaeli region, which is a high seismic region, is studied. The tanks are free-to-slide on their existing reinforced concrete foundation. The... more
Seismic performance of existing liquid pentane storage tanks located in a tank farm in Turkey Kocaeli region, which is a high seismic region, is studied. The tanks are free-to-slide on their existing reinforced concrete foundation. The tanks seismic performance is evaluated based on the 2018-Turkish Building Seismic Code and API 650 provisions using three-dimensional (3D) finite element methods with nonlinear time-history analysis. The developed FE model for seismic performance assessment of the existing tanks includes tank-foundation dynamic interaction, tank supports uplifting, and sliding over the foundation. The study revealed poor and inadequate seismic performance for the existing tanks due to lack of tank foundation-anchorage. A practical seismic retrofit strategy is developed to anchor the tanks to the existing reinforced concrete foundation. Prefabricated and field-welding free steel split sleeves are developed for the tank anchorage. The retrofitted tank seismic performance is evaluated to verify the proposed retrofit strategy and its effects on tank seismic behavior. The base shear and uplift reactions for the retrofitted tank are monitored for the anchorage design. Tank top drift, which is an important seismic performance parameter for tank piping, and tank steel material yielding are also checked to verify adequacy of the proposed retrofit strategy.
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Prediction of the dynamic performance of an offshore wind turbine (OWT) requires consideration of many different design parameters. Besides the superstructure, the OWT foundation also plays an impo...
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Pile foundations are mostly used for heavy superstructures located on offshore and onshore soft soil site conditions. Pile supported structures founded on or passing through liquefiable soils may experience significant displacements and... more
Pile foundations are mostly used for heavy superstructures located on offshore and onshore soft soil site conditions. Pile supported structures founded on or passing through liquefiable soils may experience significant displacements and may be damaged during seismic or cyclic loading. Despite the fact of assuming large safety factor in design of pile foundations, extensive damage to pile-supported bridges and structures in areas in terms of liquefaction and lateral spreading has been observed in many earthquakes around the world. Liquefaction is recognized as one of the principal seismic hazards affecting critical lifelines, superstructures and infrastructures. Predicting the dynamic behavior of a pile foundation in liquefying soil layers requires consideration of design motions, free-field site response, superstructure response, and soil-pile-superstructure interaction. One of the issues in the analysis of piles under lateral cyclic loads is the liquefaction susceptibility around t...
Unbonded post-tensioned precast shear walls remain undamaged due to lack of bond between the post-tensioned tendons and wall panels under lateral loads. However, the shear resistance along horizontal dry-joint between the wall panels... more
Unbonded post-tensioned precast shear walls remain undamaged due to lack of bond between the post-tensioned tendons and wall panels under lateral loads. However, the shear resistance along horizontal dry-joint between the wall panels relies mainly on friction resistance, which depends on dynamic friction coefficient and normal force clamping the wall panels. The normal force has two components namely, the dead load carried by the wall and post-tensioning force. However, during seismic loading, the post-tensioning force may rapidly decrease due to cyclic load reversals. Therefore, effects of post-tensioning force reduction on the joint shear resistance is a critical design parameter, which has not been adequately addressed in the literature. In this study, seismic performance of a five-story parking garage featuring unboned post-tensioned walls as the sole lateral load resisting system is investigated using nonlinear dynamic time-history analysis. The shear force and normal force his...
Scenario‐based earthquake simulations at regional scales hold the promise in advancing the state‐of‐the‐art in seismic risk assessment studies. In this study, a computational workflow is presented that combines (i) a broadband Green's... more
Scenario‐based earthquake simulations at regional scales hold the promise in advancing the state‐of‐the‐art in seismic risk assessment studies. In this study, a computational workflow is presented that combines (i) a broadband Green's function‐based fault‐rupture and ground motion simulation—herein carried out using the “UCSB (University of California at Santa Barbara) method”, (ii) a three‐dimensional physics‐based regional‐scale wave propagation simulation that is resolved at Hz, and (iii) a local soil‐foundation‐structure finite element analysis model. These models are interfaced with each other using the domain reduction method. The innermost local model—implemented in ABAQUS—is additionally enveloped with perfectly matched layer boundaries that absorb outbound waves scattered by the structures contained within it. The intermediate wave propagation simulation is carried out using Hercules, which is an explicit time‐stepping finite element code that is developed and licensed...
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Blast resistant modular steel (BRMS) buildings are prefabricated cost-effective and explosion-proof structures used to shelter personal near hazardous-material handling or storage facilities, in facilities handling high-pressure... more
Blast resistant modular steel (BRMS) buildings are prefabricated cost-effective and explosion-proof structures used to shelter personal near hazardous-material handling or storage facilities, in facilities handling high-pressure processes, and within designed blast zones in mining, petrochemical, and military industries. Typically, BRMS buildings are designed to be fixed (anchored) to their foundation. However, this design approach can result in very large anchorage and foundation reactions, which result in very large and high-cost foundations. Therefore, an alternative foundation approach which minimize foundation reactions and known as unanchored or free-to-slide foundation has recently attracted much attention for BRMS buildings. In this study, dynamic behavior of a typical BRMS building under blast loading with unanchored foundation was determined using 3D nonlinear dynamic finite element and a simplified numerical analysis method. The developed numerical analysis method is base...
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Two blast analysis methods widely used are three-dimensional finite element (FE) and uncoupled equivalent single degree of freedom (ESDOF) methods. The uncoupled equivalent ESDOF method, which is the most common blast analysis method,... more
Two blast analysis methods widely used are three-dimensional finite element (FE) and uncoupled equivalent single degree of freedom (ESDOF) methods. The uncoupled equivalent ESDOF method, which is the most common blast analysis method, provides considerable advantages and simplicity in analysis and design stages. However, the inherent assumptions and simplifications involved but especially neglecting members dynamic interactions can significantly affect accuracy of analysis results. In this study, blast performance of a prototype two-module steel blast-resistant building is evaluated using uncoupled ESDOF and FE methods. The results are compared to evaluate adequacy of uncoupled ESDOF method for blast analysis of the structure.
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... Arturo E. Schultz a * pages 1047-1064. ... 6th US National Conference on Earth. Engineering, EERI Oakland, CA 1998 View all references; Holden, 20014. Holden, TJ 2001. “A comparison of the seismic performance of precast wall... more
... Arturo E. Schultz a * pages 1047-1064. ... 6th US National Conference on Earth. Engineering, EERI Oakland, CA 1998 View all references; Holden, 20014. Holden, TJ 2001. “A comparison of the seismic performance of precast wall construction: emulation and hybrid approaches”. ...