Luis Ibarra - Academia.edu (original) (raw)

Papers by Luis Ibarra

Research paper thumbnail of Seismic anchorage of dry storage casks

Dry storage casks (DSCs) store spent nuclear fuel (SNF) rods from nuclear power plants (NPPs). DS... more Dry storage casks (DSCs) store spent nuclear fuel (SNF) rods from nuclear power plants (NPPs). DSCs are a temporary storage solution licensed for 20 years, although they may be relicensed for operation periods up to 60 years. DSCs are being re-evaluated as a potential mid-term storage solution, where operating periods may be extended to 300 years. The potential extension of DSC compliance period increases the seismic hazard, resulting in very large horizontal accelerations and destabilizing effects from vertical accelerations. DSCs are typically unanchored, but units located in moderate to high seismic regions may slide and/or tip over, damaging the cask internals. This research focuses on the benefits of seismic anchorage of DCSs. Two types of anchorage are investigated: (a) conventional bolt details with steel chairs using designs adopted from anchoring liquid storage tanks, and (b) stretch length bolt details with steel chairs, which performed very well during the 2010 Maule, Chi...

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Research paper thumbnail of Collapse Capacity Assessment of Skewed Reinforced Concrete Box Girder Bridges Retrofitted with Buckling Restrained Braces

This study assesses the seismic performance of a retrofitted three-span reinforced concrete (RC) ... more This study assesses the seismic performance of a retrofitted three-span reinforced concrete (RC) box girder bridge with asymmetric configuration. The original design of the in-situ California bridge was modified to consider bridge configurations with several skew angles that introduce different asymmetries in the bridge responses, and a retrofit strategy with buckling restrained braces (BRBs). A three-dimensional (3D) model was developed in the software OpenSees, incorporating BRBs between the columns at each bent. These columns were modeled using distributed plasticity to account for material strength and stiffness deterioration. The BRB inelastic behavior was represented using the Menegotto-Pinto model to reproduce its isotropic and kinematic strain hardening properties. The collapse capacity of bridges with different skew angles before and after being retrofitted with BRBs was evaluated by means of 3D incremental dynamic analysis (IDA) under 21 far-field ground motions, with the ...

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Research paper thumbnail of Risk Assessment of Structural Integrity of Transportation Casks after Extended Storage

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Research paper thumbnail of Seismic Assessment for Retrofitted Skewed Reinforced Concrete Bridges with Buckling Restrained Braces

In this study, buckling restrained braces (BRBs) are implemented as a potential retrofit strategy... more In this study, buckling restrained braces (BRBs) are implemented as a potential retrofit strategy to mitigate damage in skewed bridges. For this purpose, a three-span reinforced concrete (RC) box girder skewed bridge was used as a case study. A three-dimensional (3-D) model was developed in OpenSees to incorporate BRBs between bent columns. The model includes soil-structure interaction effects adjusted by recent results from skewed backfill-abutment interaction experiments. This paper assesses the impacts of five different BRB designs on the performance of skewed concrete box girder bridges with different skewed angles. Nonlinear time history analyses (THAs) were performed to assess effect of BRBs on the seismic performance of skewed bridges. The seismic behavior of skewed bridges can be significantly different from that of straight bridges due to potential torsional effects caused by the combination of longitudinal and transverse seismic responses. Therefore, optimized BRB designs ...

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Research paper thumbnail of Seismic Performance of Curved Bridges on Soft Soils Retrofitted with Buckling Restrained Braces

Geotechnical and Structural Engineering Congress 2016, 2016

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Research paper thumbnail of Shaking Table Experiments of Dry Storage Casks

The spent nuclear fuel (SNF) at nuclear power plants is initially stored in pools to control the ... more The spent nuclear fuel (SNF) at nuclear power plants is initially stored in pools to control the temperature of the fuel assemblies, and prevent melting of their cladding. Thereafter, the spent fuel is transferred to a Dry Storage Cask (DSC). Some DSCs are designed as free-standing structures resting on a reinforced concrete foundation pad. They are usually licensed for 20 years, although they can be relicensed for operating periods up to 60 years. The main goal of this study is to evaluate the long-term seismic performance of DSCs. For this purpose, experimental tests on a six-degree-of-freedom (6 DOF) shaking table were performed on 1/2.5 and 1/3.5 scaled specimens that cover the range of commercially available DSCs. According to the similitude law, the scaled DSCs need additional mass to properly reproduce the dynamic response of the original DSCs. This additional mass was provided by adding lead assemblies to the specimens. DSC specimens were designed to sustain handling, slidin...

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Research paper thumbnail of Sliding and Rocking of Free Standing Dry Storage Casks Under Earthquake Excitation

Nuclear power components must maintain a stringent safety margin during normal operation, acciden... more Nuclear power components must maintain a stringent safety margin during normal operation, accident scenarios, and seismic events. The spent nuclear fuel (SNF) at nuclear power plants is initially stored in pools to control the temperature of the fuel assemblies, and prevent melting of their cladding. Thereafter, SNF is transferred to Dry Storage Casks (DSCs), which can be designed as free-standing structures resting on a reinforced concrete foundation. DSCs have been considered as a temporary storage solution, and are usually licensed for 20 years, although they can be relicensed for operating periods up to 60 years. In order to extend relicensing periods, the increased seismic hazard on DSCs needs to be re-examined. Thus, the main goal of this study is to evaluate the long-term seismic performance of DSCs. To evaluate DSC seismic performance, experiments were conducted using a six degree-of-freedom (6DOF) shake table in the Earthquake Engineering Laboratory at the University of Nev...

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Research paper thumbnail of A Spectral Acceleration Based Intensity Measure for P-Delta Vulnerable Frames in the Collapse Limit State

The efficiency of a recently introduced spectral based intensity measure (IM) is assessed, used f... more The efficiency of a recently introduced spectral based intensity measure (IM) is assessed, used for the assessment of the seismic collapse capacity of highly inelastic frame structures with deteriorating backbone curve vulnerable to the degrading effect of gravity loads (P-delta effect). This IM is derived from the geometric mean of the spectral pseudo-acceleration over a certain period interval considering period elongation due to inelastic deformations and gravity loads, as well as higher mode effects. The IM optimization is achieved by using the mode in which 95% of the effective modal mass is exceeded as a lower bound period of the averaging interval. The IM upper bound period is 1.6 times the fundamental period. The 5%damped spectral pseudo-acceleration at the system’s fundamental period is the benchmark IM. In a parametric study on generic frames, characteristic structural parameters are varied to quantify their impact on the performance of the IMs. The proposed IM minimizes c...

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Research paper thumbnail of Experimental Dynamic Response of Free-Standing Bodies Under Near Field and Far Field Ground Motions

This study is a part of a research project evaluating seismic response of free-standing dry stora... more This study is a part of a research project evaluating seismic response of free-standing dry storage casks under long-term seismic events. Free-standing structures are highly susceptible to rocking and sliding during seismic events. Characterization of motion of three dimensional free-standing structures is a highly nonlinear problem, especially when rocking and sliding motion occur simultaneously. Response of such free-standing bodies depend on many factors like aspect ratios (radius to centroidal height ratio, r/hcg), coefficient of friction and ground motion characteristics. The main purpose of this article is to present the effect of ground motions with a single large pulse and those with multiple smaller pulses (NFGMs and FFGMs, respectively) on the dynamic response of free-standing bodies. For this purpose, experiments with Near Field and Far Field ground motions were conducted using a six degree-of-freedom (6DOF) shake table at the University of Nevada, Reno. Four scaled free-...

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Research paper thumbnail of Seismic Performance of Circular Concrete Filled Steel Tube Columns for Accelerated Bridge Construction

This study evaluates the seismic performance of circular concrete filled tube (CCFT) columns in a... more This study evaluates the seismic performance of circular concrete filled tube (CCFT) columns in accelerated bridge construction (ABC) projects. CCFT components are considered of interest for bridges subjected to seismic forces due to their efficient structural behavior under combined axial and bending loads: lateral stiffness of the steel tube is increased by the concrete and concrete confinement is provided by the steel tube. This paper addresses the ability of CCFT columns to perform adequately under gravitational and seismic loading before the concrete has reached its design strength. A reduced seismic hazard that accounts for this temporal condition is also implemented. The evaluation of performance is based on the probability of failure of the CCFT column. For this research, a Caltrans bridge used in previous PEER studies is adopted. The performance of a proposed CCFT column is compared to the original circular reinforced concrete (RC) column. Numerical analyses using concentra...

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Research paper thumbnail of Effect of High Strength Steel on the Flexural Behavior of High Strength Concrete and Fiber-Reinforced Concrete Specimens

A series of reinforced concrete (RC) components with high strength materials were tested under pu... more A series of reinforced concrete (RC) components with high strength materials were tested under pure flexural monotonic and cyclic quasi-static loading protocols. The specimen materials included high strength concrete (HSC), and ultra-high strength steel (UHSS). In some specimens steel fibers were added to the concrete mix to create high strength fiber reinforced concrete (HSFRC) specimens. The series of eight specimens include, for the first time, a nonlinear response comparison of HSC and HSFRC specimens with UHSS under monotonic and cyclic loading protocols. The use of UHSS on HSC components increased the ultimate flexural capacity by more than 60%, as compared with a similar component with conventional steel and the same steel area. However, the rotational capacity of HSCfy100 specimens decreased by more than 40% due to the lower elongation at fracture of UHSS. Also, the drift at peak strength was consistently larger for monotonic tests, underlining the need of carrying out monot...

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Research paper thumbnail of Impact of ground motion selection methods on the seismic assessment of steel special moment frames

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Research paper thumbnail of Influences of Mechanism Control for Reinforced Concrete Frame Structures on Processes of Damage and Probabilities of Collapse

Journal of Structural and Construction Engineering (Transactions of AIJ), 2005

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Research paper thumbnail of Intensity measures that reduce collapse capacity dispersion of P-delta vulnerable simple systems

Bulletin of Earthquake Engineering, 2016

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Research paper thumbnail of Seismic Performance of Dry Casks Storage for Long- Term Exposure

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Research paper thumbnail of Record-To-Record Variability of the Collapse Capacity of Multi-Story Frame Structures Vulnerable to P-Delta

In this paper the record-to-record variability of the collapse capacity of highly inelastic multi... more In this paper the record-to-record variability of the collapse capacity of highly inelastic multi-story frame structures is evaluated. These frames are vulnerable to the destabilizing effect of gravity loads (P-delta effect). In particular, the effect of different spectral pseudo-acceleration based intensity measures (IMs) at target periods, or alternatively, averaged over a certain period range is evaluated. In a parametric study on generic frame structures characteristic specific structural parameters are varied to quantify their impact on the collapse capacity dispersion. From the results it can be concluded that it should be strictly distinguished between single-degree-of-freedom (SDOF) and multi-degree-of-freedom (MDOF) structures when selecting the underlying IM for the definition of the collapse capacity. For MDOF structures consideration of higher modes in the IM leads to the smallest dispersion. In a SDOF system, however, an averaged intensity measure including periods belo...

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Research paper thumbnail of Seismic Demands and Capacities of Single-Story and Low-Rise Multi-Story Woodframe Structures

SUMMARY This paper summarizes a systematic process for the evaluation of seismic demands imposed ... more SUMMARY This paper summarizes a systematic process for the evaluation of seismic demands imposed by ground motions on single-story and low-rise woodframe structures. This process involves development of representative sets of ground motions and scaling them to specific hazard levels, development of analytical component models that closely simulate experimental results (including monotonic and cyclic strength deterioration), and utilization of analytical models in the development of a new representation of seismic ...

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Research paper thumbnail of Seismic rehabilitation of skewed and curved bridges using a new generation of buckling restrained braces

The objective of this project is to find effective configurations for using buckling restrained b... more The objective of this project is to find effective configurations for using buckling restrained braces (BRBs) in both skewed and curved bridges for reducing the effects of strong earthquakes. Verification is performed by numerical simulation using analytical models of existing bridges when BRBs are implemented for control of seismic forces. The effect of ground motion incidence angle on the responses of skewed bridges retrofitted with BRBs in the bents is evaluated. A three-span skewed bridge with no retrofit was used as a baseline case. The assessment is carried out in OpenSees using a model that accounts for the BRBs between bent columns, abutment, and shear keys, as well as soil-structure interaction effects. The models are subjected to 21 farfield ground motions, and the maximum response under 11 incidence angles is obtained. The two components in each ground motion set are first rotated to their principal directions to minimize correlation among horizontal orthogonal directions...

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Research paper thumbnail of Basic concepts and performance measures in prediction of collapse of buildings under earthquake ground motions

The Structural Design of Tall and Special Buildings, 2009

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Research paper thumbnail of Decision support for conceptual performance-based design

Earthquake Engineering & Structural Dynamics, 2006

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Research paper thumbnail of Seismic anchorage of dry storage casks

Dry storage casks (DSCs) store spent nuclear fuel (SNF) rods from nuclear power plants (NPPs). DS... more Dry storage casks (DSCs) store spent nuclear fuel (SNF) rods from nuclear power plants (NPPs). DSCs are a temporary storage solution licensed for 20 years, although they may be relicensed for operation periods up to 60 years. DSCs are being re-evaluated as a potential mid-term storage solution, where operating periods may be extended to 300 years. The potential extension of DSC compliance period increases the seismic hazard, resulting in very large horizontal accelerations and destabilizing effects from vertical accelerations. DSCs are typically unanchored, but units located in moderate to high seismic regions may slide and/or tip over, damaging the cask internals. This research focuses on the benefits of seismic anchorage of DCSs. Two types of anchorage are investigated: (a) conventional bolt details with steel chairs using designs adopted from anchoring liquid storage tanks, and (b) stretch length bolt details with steel chairs, which performed very well during the 2010 Maule, Chi...

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Research paper thumbnail of Collapse Capacity Assessment of Skewed Reinforced Concrete Box Girder Bridges Retrofitted with Buckling Restrained Braces

This study assesses the seismic performance of a retrofitted three-span reinforced concrete (RC) ... more This study assesses the seismic performance of a retrofitted three-span reinforced concrete (RC) box girder bridge with asymmetric configuration. The original design of the in-situ California bridge was modified to consider bridge configurations with several skew angles that introduce different asymmetries in the bridge responses, and a retrofit strategy with buckling restrained braces (BRBs). A three-dimensional (3D) model was developed in the software OpenSees, incorporating BRBs between the columns at each bent. These columns were modeled using distributed plasticity to account for material strength and stiffness deterioration. The BRB inelastic behavior was represented using the Menegotto-Pinto model to reproduce its isotropic and kinematic strain hardening properties. The collapse capacity of bridges with different skew angles before and after being retrofitted with BRBs was evaluated by means of 3D incremental dynamic analysis (IDA) under 21 far-field ground motions, with the ...

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Research paper thumbnail of Risk Assessment of Structural Integrity of Transportation Casks after Extended Storage

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Seismic Assessment for Retrofitted Skewed Reinforced Concrete Bridges with Buckling Restrained Braces

In this study, buckling restrained braces (BRBs) are implemented as a potential retrofit strategy... more In this study, buckling restrained braces (BRBs) are implemented as a potential retrofit strategy to mitigate damage in skewed bridges. For this purpose, a three-span reinforced concrete (RC) box girder skewed bridge was used as a case study. A three-dimensional (3-D) model was developed in OpenSees to incorporate BRBs between bent columns. The model includes soil-structure interaction effects adjusted by recent results from skewed backfill-abutment interaction experiments. This paper assesses the impacts of five different BRB designs on the performance of skewed concrete box girder bridges with different skewed angles. Nonlinear time history analyses (THAs) were performed to assess effect of BRBs on the seismic performance of skewed bridges. The seismic behavior of skewed bridges can be significantly different from that of straight bridges due to potential torsional effects caused by the combination of longitudinal and transverse seismic responses. Therefore, optimized BRB designs ...

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Research paper thumbnail of Seismic Performance of Curved Bridges on Soft Soils Retrofitted with Buckling Restrained Braces

Geotechnical and Structural Engineering Congress 2016, 2016

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Research paper thumbnail of Shaking Table Experiments of Dry Storage Casks

The spent nuclear fuel (SNF) at nuclear power plants is initially stored in pools to control the ... more The spent nuclear fuel (SNF) at nuclear power plants is initially stored in pools to control the temperature of the fuel assemblies, and prevent melting of their cladding. Thereafter, the spent fuel is transferred to a Dry Storage Cask (DSC). Some DSCs are designed as free-standing structures resting on a reinforced concrete foundation pad. They are usually licensed for 20 years, although they can be relicensed for operating periods up to 60 years. The main goal of this study is to evaluate the long-term seismic performance of DSCs. For this purpose, experimental tests on a six-degree-of-freedom (6 DOF) shaking table were performed on 1/2.5 and 1/3.5 scaled specimens that cover the range of commercially available DSCs. According to the similitude law, the scaled DSCs need additional mass to properly reproduce the dynamic response of the original DSCs. This additional mass was provided by adding lead assemblies to the specimens. DSC specimens were designed to sustain handling, slidin...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Sliding and Rocking of Free Standing Dry Storage Casks Under Earthquake Excitation

Nuclear power components must maintain a stringent safety margin during normal operation, acciden... more Nuclear power components must maintain a stringent safety margin during normal operation, accident scenarios, and seismic events. The spent nuclear fuel (SNF) at nuclear power plants is initially stored in pools to control the temperature of the fuel assemblies, and prevent melting of their cladding. Thereafter, SNF is transferred to Dry Storage Casks (DSCs), which can be designed as free-standing structures resting on a reinforced concrete foundation. DSCs have been considered as a temporary storage solution, and are usually licensed for 20 years, although they can be relicensed for operating periods up to 60 years. In order to extend relicensing periods, the increased seismic hazard on DSCs needs to be re-examined. Thus, the main goal of this study is to evaluate the long-term seismic performance of DSCs. To evaluate DSC seismic performance, experiments were conducted using a six degree-of-freedom (6DOF) shake table in the Earthquake Engineering Laboratory at the University of Nev...

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Research paper thumbnail of A Spectral Acceleration Based Intensity Measure for P-Delta Vulnerable Frames in the Collapse Limit State

The efficiency of a recently introduced spectral based intensity measure (IM) is assessed, used f... more The efficiency of a recently introduced spectral based intensity measure (IM) is assessed, used for the assessment of the seismic collapse capacity of highly inelastic frame structures with deteriorating backbone curve vulnerable to the degrading effect of gravity loads (P-delta effect). This IM is derived from the geometric mean of the spectral pseudo-acceleration over a certain period interval considering period elongation due to inelastic deformations and gravity loads, as well as higher mode effects. The IM optimization is achieved by using the mode in which 95% of the effective modal mass is exceeded as a lower bound period of the averaging interval. The IM upper bound period is 1.6 times the fundamental period. The 5%damped spectral pseudo-acceleration at the system’s fundamental period is the benchmark IM. In a parametric study on generic frames, characteristic structural parameters are varied to quantify their impact on the performance of the IMs. The proposed IM minimizes c...

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Research paper thumbnail of Experimental Dynamic Response of Free-Standing Bodies Under Near Field and Far Field Ground Motions

This study is a part of a research project evaluating seismic response of free-standing dry stora... more This study is a part of a research project evaluating seismic response of free-standing dry storage casks under long-term seismic events. Free-standing structures are highly susceptible to rocking and sliding during seismic events. Characterization of motion of three dimensional free-standing structures is a highly nonlinear problem, especially when rocking and sliding motion occur simultaneously. Response of such free-standing bodies depend on many factors like aspect ratios (radius to centroidal height ratio, r/hcg), coefficient of friction and ground motion characteristics. The main purpose of this article is to present the effect of ground motions with a single large pulse and those with multiple smaller pulses (NFGMs and FFGMs, respectively) on the dynamic response of free-standing bodies. For this purpose, experiments with Near Field and Far Field ground motions were conducted using a six degree-of-freedom (6DOF) shake table at the University of Nevada, Reno. Four scaled free-...

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Research paper thumbnail of Seismic Performance of Circular Concrete Filled Steel Tube Columns for Accelerated Bridge Construction

This study evaluates the seismic performance of circular concrete filled tube (CCFT) columns in a... more This study evaluates the seismic performance of circular concrete filled tube (CCFT) columns in accelerated bridge construction (ABC) projects. CCFT components are considered of interest for bridges subjected to seismic forces due to their efficient structural behavior under combined axial and bending loads: lateral stiffness of the steel tube is increased by the concrete and concrete confinement is provided by the steel tube. This paper addresses the ability of CCFT columns to perform adequately under gravitational and seismic loading before the concrete has reached its design strength. A reduced seismic hazard that accounts for this temporal condition is also implemented. The evaluation of performance is based on the probability of failure of the CCFT column. For this research, a Caltrans bridge used in previous PEER studies is adopted. The performance of a proposed CCFT column is compared to the original circular reinforced concrete (RC) column. Numerical analyses using concentra...

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Research paper thumbnail of Effect of High Strength Steel on the Flexural Behavior of High Strength Concrete and Fiber-Reinforced Concrete Specimens

A series of reinforced concrete (RC) components with high strength materials were tested under pu... more A series of reinforced concrete (RC) components with high strength materials were tested under pure flexural monotonic and cyclic quasi-static loading protocols. The specimen materials included high strength concrete (HSC), and ultra-high strength steel (UHSS). In some specimens steel fibers were added to the concrete mix to create high strength fiber reinforced concrete (HSFRC) specimens. The series of eight specimens include, for the first time, a nonlinear response comparison of HSC and HSFRC specimens with UHSS under monotonic and cyclic loading protocols. The use of UHSS on HSC components increased the ultimate flexural capacity by more than 60%, as compared with a similar component with conventional steel and the same steel area. However, the rotational capacity of HSCfy100 specimens decreased by more than 40% due to the lower elongation at fracture of UHSS. Also, the drift at peak strength was consistently larger for monotonic tests, underlining the need of carrying out monot...

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Research paper thumbnail of Impact of ground motion selection methods on the seismic assessment of steel special moment frames

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Influences of Mechanism Control for Reinforced Concrete Frame Structures on Processes of Damage and Probabilities of Collapse

Journal of Structural and Construction Engineering (Transactions of AIJ), 2005

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Intensity measures that reduce collapse capacity dispersion of P-delta vulnerable simple systems

Bulletin of Earthquake Engineering, 2016

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Research paper thumbnail of Seismic Performance of Dry Casks Storage for Long- Term Exposure

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Record-To-Record Variability of the Collapse Capacity of Multi-Story Frame Structures Vulnerable to P-Delta

In this paper the record-to-record variability of the collapse capacity of highly inelastic multi... more In this paper the record-to-record variability of the collapse capacity of highly inelastic multi-story frame structures is evaluated. These frames are vulnerable to the destabilizing effect of gravity loads (P-delta effect). In particular, the effect of different spectral pseudo-acceleration based intensity measures (IMs) at target periods, or alternatively, averaged over a certain period range is evaluated. In a parametric study on generic frame structures characteristic specific structural parameters are varied to quantify their impact on the collapse capacity dispersion. From the results it can be concluded that it should be strictly distinguished between single-degree-of-freedom (SDOF) and multi-degree-of-freedom (MDOF) structures when selecting the underlying IM for the definition of the collapse capacity. For MDOF structures consideration of higher modes in the IM leads to the smallest dispersion. In a SDOF system, however, an averaged intensity measure including periods belo...

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Research paper thumbnail of Seismic Demands and Capacities of Single-Story and Low-Rise Multi-Story Woodframe Structures

SUMMARY This paper summarizes a systematic process for the evaluation of seismic demands imposed ... more SUMMARY This paper summarizes a systematic process for the evaluation of seismic demands imposed by ground motions on single-story and low-rise woodframe structures. This process involves development of representative sets of ground motions and scaling them to specific hazard levels, development of analytical component models that closely simulate experimental results (including monotonic and cyclic strength deterioration), and utilization of analytical models in the development of a new representation of seismic ...

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Research paper thumbnail of Seismic rehabilitation of skewed and curved bridges using a new generation of buckling restrained braces

The objective of this project is to find effective configurations for using buckling restrained b... more The objective of this project is to find effective configurations for using buckling restrained braces (BRBs) in both skewed and curved bridges for reducing the effects of strong earthquakes. Verification is performed by numerical simulation using analytical models of existing bridges when BRBs are implemented for control of seismic forces. The effect of ground motion incidence angle on the responses of skewed bridges retrofitted with BRBs in the bents is evaluated. A three-span skewed bridge with no retrofit was used as a baseline case. The assessment is carried out in OpenSees using a model that accounts for the BRBs between bent columns, abutment, and shear keys, as well as soil-structure interaction effects. The models are subjected to 21 farfield ground motions, and the maximum response under 11 incidence angles is obtained. The two components in each ground motion set are first rotated to their principal directions to minimize correlation among horizontal orthogonal directions...

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Research paper thumbnail of Basic concepts and performance measures in prediction of collapse of buildings under earthquake ground motions

The Structural Design of Tall and Special Buildings, 2009

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Research paper thumbnail of Decision support for conceptual performance-based design

Earthquake Engineering & Structural Dynamics, 2006

Bookmarks Related papers MentionsView impact