Federico Valenzuela-Beltrán

Universidad Autónoma de Sinaloa · Facultad de Ingeniería

Structural engineers often use deep columns in high seismic areas to reduce drifts, yet this somehow contradicts what is stated in some tests in the sense that even though deep columns may satisfy current seismic provisions, they can suffer premature twisting; this is an indication that a lot of research is needed in this area. Numerical and experi...

There have been significant advances concerning seismic analysis and design procedures for steel buildings. Emerging procedures as the performance-based seismic design and the resilient seismic design , are examples of such advances. However, there is a long road ahead before these new concepts can be widely accepted and implemented by structural e...

The selection of an appropriate intensity measure to assess the seismic performance in steel buildings is an important step to reduce uncertainty in the structural response. Hence, in this study, a scalar ground motion intensity measure able to increase the efficiency in the prediction of nonlinear behavior effects of steel structures subjected to...

The catastrophic power of earthquakes has been reported in numerous documents. For example, the occurrence of certain ground motions as the 1985 Mexico City, 1989 Loma Prieta, 1994 Northridge, and 1995 Kobe, represented economic losses of about 4, 6, 30, and 200 billion dollars, respectively. During the shaking of the above-mentioned and several ot...

Se presentan los resultados de un estudio numérico para evaluar la reducción de la respuesta producida por fluencia del material y amortiguamiento viscoso en marcos de acero resistentes a momento (SMRFs) modelados como sistemas complejos de varios grados de libertad. Se consideran tres modelos que representan edificios de acero de baja, media y gra...

Seismic analysis of buildings is normally based on a damping matrix derived from the Rayleigh Model (CR). However, it is accepted that the damping matrix (CS) derived from the superposition of modal damping matrices (SMDM) gives more accurate results. Another issue related to seismic analysis of structures consists in the overlooking of the contrib...

An alternative probabilistic assessment of buildings excited by multi-level seismic loading is presented in this paper. This evaluation is developed for both steel and reinforced concrete buildings using the Performance-Based Seismic Design (PBSD) concept. The methodology implements Probability Density Functions (PDFs) of inter-story drifts to extr...

Seismic analysis of steel buildings is usually based on the use of the concentrated mass (ML) matrix and the Rayleigh damping matrix (C). Similarly, the initial stiffness matrix (KO) and the first two modes associated to lateral vibrations are commonly used to develop the matrix C. The evaluation of the accuracy of these practices for the particula...

A study focused on evaluating the influence of higher modes of vibration on the seismic design of buildings with viscous dampers is presented. In the first part of the study, expressions to estimate velocity and acceleration correction factors, applicable to Mexico City, are proposed. In the second part, a numerical evaluation of two buildings with...

A lo largo de la historia, los terremotos han sido una de las principales causas de enormes daños en edificaciones. En este artículo, se investiga la confiabilidad estructural de edificios de mediana altura de concreto reforzado sometidos a terremotos considerando tres niveles de desempeño: (1) ocupación inmediata, (2) seguridad de vida, y (3) prev...

En este artículo, se presenta el estudio del desempeño sísmico y confiabilidad estructural de marcos de acero con contravientos concéntricos tipo Chevrón y marcos resistentes a momento, considerando múltiples niveles de desempeño. Para llevar a cabo esta investigación se integraron los conceptos de elementos finitos, análisis de confiabilidad estru...

En la actualidad, es bien sabido que los sismos de gran magnitud pueden ser catastróficos para la sociedad, provocando el colapso de edificios lo que conlleva a grandes pérdidas tanto económicas como humanas. Aunque el diseño de estructuras sismo-resistentes se basa en reglamentos y normas vigentes, se han registrado numerosas edificaciones que aun...

La gran mayoría de las técnicas para la implementación del diseño sísmico basado en desempeño se basan en métodos determinísticos que solamente analizan el desempeño relacionado a la pérdida de rigidez de las estructuras asociada a desplazamientos provocados por la demanda sísmica, donde en un gran número de ocasiones se utilizan métodos estáticos...

El propósito de esta investigación fue estudiar y comparar el desempeño sísmico mediante análisis no lineales paso a paso en el dominio del tiempo de edificios estructurados a base de marcos de acero con contravientos tipo X y marcos de acero resistentes a momento, situados en la ciudad de Culiacán, Sinaloa, México. La investigación se desarrolló i...

En este trabajo se presenta una evaluación de las pérdidas económicas esperadas por daños para dos edificios de concreto reforzado sometidos a distintos niveles de intensidad sísmica y localizados en suelo blando de la Ciudad de México. Los edificios se diseñaron siguiendo los lineamientos de las NTC-17 y cuentan con diferentes características de d...

Una de las principales causas de daños en las edificaciones de concreto reforzado son los sismos. De manera general, la implementación de muros de cortante en edificaciones ayuda a disminuir la probabilidad de colapso ante sismos de gran magnitud. El poder destructivo y los daños económicos consecuentes de estos fenómenos han puesto a discusión el...

The results of an experimental study of four infilled frames with brick masonry walls subject to reversal cyclic lateral load are presented. The variables studied were the height to length aspect ratio of the wall and the use of joint reinforcement. The investigation was motivated by the fact that the Mexican code establishes the same specification...

In this study, the generalized intensity measure (IM) named INpg is analyzed. The recently proposed proxy of the spectral shape named Npg is the base of this intensity measure, which is similar to the traditional Np based on the spectral shape in terms of pseudo-acceleration; however, in this case the new generalized intensity measure can be define...

The response of steel moment frames is estimated by first considering that the mass matrix is the concentrated type (ML) and then consistent type (MC). The effect of considering more than one element per beam is also evaluated. Low-, mid- and high-rise frames, modeled as complex-2D-MDOF systems, are used in the numerical study. Results indicate tha...

A numerical study is carried out to evaluate the precision of expressing the dissipated energy by hysteretic behavior of the material (HBM) in terms of viscous damping (VD), as specified in the Capacity Spectrum Method (CSM)(ATC 40, FEMA 440) and in modal seismic analysis (MSA), by using nonlinear time history analysis (NTHA). Initially, the equiva...

Software users concerning seismic analysis of buildings usually use the concentrated mass (ML) matrix and the Rayleigh damping matrix (C). Similarly, the initial stiffness matrix (KO) and the first two modes are commonly used to calculate C. In addition, it is commonly believed that damping forces are small so there are no significant errors if the...

A high percentage of mid-rise soft-first-story (SFS) reinforced concrete (RC) buildings with masonry infill in upper stories collapsed in Mexico City during the SEPT/19/2017 earthquake. For this reason, in this work, a SFS building with similar structural characteristics to those damaged during such an event is subjected to several ground motions r...

The corrosion process due to the erosion of chloride ions on reinforced concrete (RC) buildings is analyzed in this paper. The main objective of this study is to determine the influence of the corrosion on structural reliability of reinforced concrete buildings under earthquakes. It is assumed that the buildings are located in the city of Acapulco...

Se compara la fragilidad de edificios ante efectos del viento en términos de la aceleración de piso, para la evaluación del confort de sus ocupantes. La fragilidad se ilustra por medio del estudio de un edificio de 28 niveles con una gran área expuesta. El edificio se diseña de dos maneras: a) convencionalmente (sin amortiguamiento suplementario),...

A numerical study to evaluate the reliability of 3D steel buildings with moment-resisting frames (MRFs) at the perimeter and gravity frames (GFs) at the interior under the action of seismic loading, is carried out. To this aim, the median values (MV) of the maximum drifts (MD) and fragility curves are obtained. The reliability, expressed as the mea...

An evaluation of some structural parameters affecting the amplitude and height-wise distribution of peak and residual drift demands of reinforced concrete frame buildings modeled as 3D complex MDOF systems is presented. In addition, the influence of different ground motion selection methods on the uncertainty in the estimation of both peak and resi...

The force reduction factor (R) and its components for steel buildings are evaluated in this study. The R factor for single-degree-of-freedom models produces non-conservative designs. The global R values can be very different than the local ones. The contribution of damping to R is much more uniformly distributed and different than that of yield, im...

The force reduction factor (R) and its components for steel buildings are evaluated in this study. The R factor for single-degree-of-freedom models produces non-conservative designs. The global R values can be very different than the local ones. The contribution of damping to R is much more uniformly distributed and different than that of yield, im...

Se presenta un criterio basado en un análisis de confiabilidad para estimar factores de amplificación de resistencia para estructuras con asimetría en fluencia. La metodología involucra el cálculo de tasas medias anuales de excedencia de la demanda estructural de sistemas con diferentes niveles de asimetría. Se proponen expresiones matemáticas simp...

A study regarding the effectiveness of non-linear fluid viscous dampers in controlling the wind-induced vibration on buildings is presented. For this purpose, a 28-story building with a large area exposed to wind is designed in two different ways: a) conventionally (without supplemental damping), and b) using non-linear fluid viscous dissipating de...

A framework for multi-hazard risk assessment (considering earthquake and wind actions) is presented. It is illustrated by the analysis of a 28-story building with a large area exposed to wind. The building is designed in two alternative ways: a) conventionally (without supplemental damping), and b) using non-linear fluid viscous devices. Both build...

In this paper, an alternative reliability-based methodology is developed and implemented on the safety evaluation of structures subjected to seismic loading. To effectively elaborate the approach, structures are represented by finite elements and seismic loading is applied in time domain. The accuracy of the proposed reliability-based methodology i...

This paper develops a performance-based seismic design (PBSD) procedure specifically for steel structures. Several improved steel connections were proposed to eliminate brittle fractures in welds following the Northridge earthquake of 1994. Making connections more flexible was considered to be an attractive option. One type of flexible connection c...

A comparison of specifications given by three Guidelines for seismic design of structures with passive energy dissipation devices is presented. The guidelines analyzed are: I) Minimum Design Load for Buildings and other Structures ASCE/SEI 7-10, II) European Standard Anti-seismic devices EN 15129, and III) Complementary Technical Norms for Seismic...

A reliability-based criterion to estimate strength amplification factors for buildings with asymmetric yielding located within a seismic region presenting different soil conditions is proposed and applied. The approach involves the calculation of the mean annual rate of exceedance of structural demands of systems with different levels of asymmetric...

A reliability-based criterion to estimate strength amplification factors for buildings with asymmetric yielding located within a seismic region presenting different soil conditions is proposed and applied. The approach involves the calculation of the mean annual rate of exceedance of structural demands of systems with different levels of asymmetric...

En este estudio se propone y aplica una metodología basada en un análisis de confiabilidad para obtener expresiones matemáticas simplificadas que permitan estimar factores de amplificación de resistencia para el diseño de estructuras nuevas o existentes, con asimetría en fluencia. La metodología involucra el cálculo de curvas de vulnerabilidad y ta...

Las expresiones que se recomendaban en las Normas Técnicas Complementarias para Diseño por Sismo (NTCDS-2004) del Reglamento de Construcciones del Distrito Federal (RCDF-2004) referentes a estructuras con comportamiento asimétrico no tomaban en cuenta parámetros que son importantes en el desempeño sísmico de las edificaciones. Las NTCDS-2017 incluy...

Se comparan resultados obtenidos con dos métodos simplificados para el diseño de estructuras con amortiguadores viscosos no lineales, siguiendo los pasos generales que recomiendan los documentos ASCE /SEI 7-10 y FEMA P 1050-1, pero con algunas adaptaciones de acuerdo con las Normas Técnicas Complementarias para Diseño por Sismo (2017). Los métodos...

Some factors influencing the accuracy of the 30 % and SRSS rules commonly used to combine the effects of individual seismic components, are studied. For MDOF systems and earthquake loading the rules underestimate the axial load, but reasonably overestimate the shears. The rules are not always inaccurate in the estimation of the response for correla...

A reliability-based methodology to estimate the additional strength required for the reinforcement of existing tilted structures, is proposed. Several nonlinear time history analyses of structural systems with different levels of asymmetric yielding are carried out. The seismic analyses consider the effect of two orthogonal components of the seismi...

A reliability-based methodology to estimate strength amplification factors for structures with asymmetric yielding is proposed. The approach is based on structural demand hazard analyses. Nonlinear time-history analyses of tridimensional simplified systems are carried out. The effects of two orthogonal components of the seismic ground motions and s...

The Maximum seismic responses of steel buildings with perimeter moment resisting frames (MRF), modeled as complex MDOF systems, are estimated for several incidence angles of the horizontal components and the critical one is identified. The accuracy of the existing rules to combine the effects of the individual components is also studied. Two and th...

Se presentan formas de expresiones matemáticas correspondientes a cocientes entre espectros de aceleración y pseudo-aceleración, así como cocientes entre espectros de velocidad y pseudo-velocidad de movimientos sísmicos registrados en el valle de México. Las expresiones propuestas están en función del periodo de vibración estructural y de la relaci...

La precisión de las reglas de combinación del 30% y SRSS, y la orientación crítica de las componentes de terremotos se estudian en este trabajo. Se analizan modelos estructurales complejos que representan edificios de baja y mediana altura. Se realiza un análisis estadístico de la precisión de las reglas de combinación aplicadas a parámetros de res...

A reliability-based methodology which uses structural demand hazard curves to consider the increment of the ductility demands of structures with tilting is proposed. The approach considers the effect of two orthogonal components of the ground motions as well as the influence of soil-structure interaction. The approach involves the calculation of du...

A reliability-based methodology which uses structural demand hazard curves to consider the increment of the ductility demands of structures with tilting is proposed. The approach considers the effect of two orthogonal components of the ground motions as well as the influence of soil-structure interaction. The approach involves the calculation of du...

The accuracy of the 30% and SRSS rules, the critical orientation of the components of earthquakes, and some related issues, are studied in this work. Complex structural models representing low and medium height buildings are analyzed. A statistical analysis of the precision of the combination rules, applied to individual and multiple response param...

The seismic responses of 3D steel buildings with perimeter moment resisting frames (PMRF), modeled as complex MDOF systems, are estimated and the accuracy of the commonly used rules to combine the individual effects of the seismic components, as well as the influence of the correlation of the components and the correlation of the individual effects...

La precisión de las reglas del 30% y SRSS, la orientación crítica de las componentes, y algunos aspectos relacionados, se estudian en este trabajo. Para sistemas complejos y carga sísmica, ambas reglas subestiman la carga axial alrededor del 10% y la incertidumbre en la estimación es alrededor del 20%. Para cortantes de entrepiso y basal, ambas reg...

: The accuracy of the 30% and the SRSS combination rules used to combine the effects of individual components of earthquakes is studied. Results indicate that for complex systems both rules may underestimate the axial load, but accurately estimate the base shear. The effect of individual components may be highly correlated for normal and principal...

The accuracy of the 30% and SRSS rules, commonly used to estimate the combined response of structures, and some related issues, are studied. For complex systems and earthquake loading, the principal components give the maximum seismic response. Both rules underestimate the axial load by about 10% and the COV of the underestimation is about 20%. Bot...