No description available.

During the past several decades, earthquakes have caused extensive damage to buildings, including wood-frame, single-family dwellings, in the United States. In order to mitigate future losses, existing buildings in earthquake prone areas should be evaluated for their seismic safety. This is also an important issue for buildings in Oregon due to the Cascadia subduction zone along its west coast. One seismically vulnerable element observed in wood-frame, single-family dwellings is the shear walls. In general, assessment of shear wall seismic performance can be accomplished by a building-specific engineering calculation. Extra effort is required if the effects of plan irregularity are a concern. This project aims to facilitate seismic evaluation of wood-frame dwellings by proposing a new engineering-based rapid visual screening method to examine the expected performance level of the structure's exterior shear walls to resist lateral forces from ground motions, including torsional forces induced from plan irregularity. In order to achieve the objective, SAPWood software was used to perform a series of nonlinear time-history analyses for 480 representative models, covering different combinations of shape parameters and shear wall opening-related parameters. The evolutionary parameter hysteresis model was used to represent the load-displacement relationship of structural panel-sheathed shear walls and a ten parameter CUREE hysteresis model for gypsum wallboard sheathed walls. The calculated maximum lateral drifts were used as basic information for the development of the new method. Through the development process, the significance of both plan configuration and shear wall openings were emphasized as they affect the overall seismic performance of a building through building mass, lateral stiffnesses, and eccentricities. Within the study range, single-family dwellings with two stories, a larger percentage of openings, and having a garage door were shown to be more vulnerable to seismic events. Plan configuration and shear wall openings were important features especially in houses located in high 1 (0.5g ≤ S[subscript a] < 1.0g) and high 2 (1.0g ≤ S[subscript a] < 1.5g) seismicity regions, as they could potentially lead to severe damage. For low and moderate seismicity, the performance ranges from satisfying the collapse prevention limit to the immediate occupancy limit. The developed piRVS (plan irregularity Rapid Visual Screening) takes into consideration the shape of the floor plan, number of stories, base rectangular area, percent cutoff, and openings from doors/windows and garage doors, and supports evaluation at the immediate occupancy (IO), life safety (LS), and collapse prevention (CP) performance levels. The piRVS provides relatively more conservative assessment results than FEMA 154 and ASCE 31 Tier 1. Its prediction for the two applicable Northridge earthquake damage samples is reasonable. This method will help architects, engineers, building officials, and trained inspectors in examining the expected seismic performance of shear walls, considering the effects of plan irregularity in wood-frame, single-family dwellings / Graduation date: 2012

Integral abutment bridges are jointless bridges in which the deck is continuous and connected monolithically with the abutment walls supported typically by a single row of piles. This thesis focuses on the effects of two major parameters on the seismic behavior of an integral abutment bridge in Tennessee by considering soil-structure interaction around the piles and in back of the abutments: (1) clay stiffness (medium vs. hard) around the piles, and (2) level of sand compaction (loose vs. dense) of the abutment wall backfilling. Modal and nonlinear time history analyses are performed on a three dimensional detailed bridge model using the commercial software SAP2000, which clearly show that (1) compacting the backfilling of the abutment wall will increase the bridge dominant longitudinal natural frequency considerably more than increasing the clay stiffness around the piles; (2) the maximum deflection and bending moment in the piles under seismic loading will happen at the pile-abutment interface; (3) under seismic loading, densely-compacted backfilling of the abutment wall is generally recommended since it will reduce the pile deflection, the abutment displacement, the moments in the steel girder, and particularly the pile moments; (4) under seismic loading, when the piles are located in firmer clay, although the pile deflection, the abutment displacement, and the maximum girder moment at the pier and the mid-span will decrease, the maximum pile moment and the maximum girder moment at the abutment will increase.

In the last 35 years, several researchers have proposed, developed and tested different friction devices for seismic control of structures. Their research has demonstrated that such devices are simple, economical, practical, durable and very effective. However, research on passive friction dampers, except for few instances, has not been given appropriate attention lately. This has caused some of the results of old studies to become out-of-date, lose their validity in the context of today's design philosophies or to fall short on the expectations of this century's structural engineering. An analytical study on the behavior of friction devices and the effect they have on the structures into which they are incorporated has been undertaken to address the new design trends, codes, evaluation criteria and needs of today's society. The present study consists of around 7,000 structural analyses that are used to show the excellent seismic performance and economic advantages of Friction Damped Braced Frames. It serves, at the same time, to improve our understanding on their dynamic behavior. Finally, this thesis also sets the basis for future research on the application of this type of seismic energy dissipating systems.

Guyed masts are special type of structures that are widely used in the telecommunication industry. In the past, there was no guideline for seismic design of these types of structures in the corresponding design codes. On the other hand, in the latest &ldquo / G&rdquo / revision of the ANSI/TIA-EIA code there is a comprehensive design criterion for the seismic design of the guyed masts. However, during the design process of these structures the most common approach is to ignore the effect of seismic loading and use only the internal forces developed from the wind load and ice load analysis. In this study firstly the efficiency and accuracy of the commercial SAP2000 and PLS-TOWER software were investigated, then finite element models of three guyed masts that had been designed in Turkey with the heights 30m, 60m and 100m in the SAP2000 and PLS-TOWER software were analyzed under the effect of earthquake, wind and ice loadings. The most common design code recognized all over the world used for the design of the guyed masts is ANSI/TIA-EIA 222-G &ldquo / Structural Standards for Steel Antenna Towers and Supporting Structures&rdquo / . Thus, the corresponding sections of this code were followed during the study. The main objective of this research is to check the correctness of commercial SAP2000 and PLS-TOWER software and to investigate the effect of seismic actions on the guyed masts and also to gain a better understanding of the behavior of guyed masts under the effects of the wind, ice and earthquake loadings.

In today&rsquo / s world, buried structures are used for a variety of purposes in many areas such as transportation, underground depot areas, metro stations and water transportation. The serviceability of these structures is crucial in many cases following an earthquake / that is, the earthquake should not impose such damage leading to the loss of serviceability of the structure. The seismic design methodology utilized for these structures differs in many ways from the above ground structures. The most commonly utilized approach in dynamic analysis of underground structures is to neglect the inertial forces of the substructures since these forces are relatively insignificant contrary to the case of surface structures. In seismic design of these underground structures, different approaches are utilized like free-field deformation approach and soil-structure interaction approach. Within the confines of this thesis, seismic response of highway tunnels is considered through a case study on Bolu Tunnels, which are well documented and subjected to D&uuml / zce earthquake. In the analyses, the seismic response of a section of the Bolu tunnels is examined with 2-D finite element models and results are compared with the recorded data to evaluate the capability of the available analysis methods. In general, the results of analyses did not show any distinct difference from the recorded data regarding the seismic performance of the analyzed section and that the liner capacities were sufficient, which is consistent with the post earthquake condition of the Bolu Tunnels.

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En la evaluación estructural y ampliación de niveles para el cambio de uso de la casa del adulto mayor a centro comercial en el distrito de la molina, se determina que tan factible puede ser darle un uso comercial a una casa del adulto mayor que con las modificaciones necesarias a nivel de estructura como la ampliación de la misma en 3 niveles, nos brinda un negocio potencialmente rentable, gracias a la zona comercial donde se encuentra ubicada avenida alameda del corregidor – Cuadra 5 y el área aproximada de 700m2. Por ello ,tenemos como objetivo general evaluar la estructura de una casa del adulto mayor para el cambio de uso a centro comercial en el distrito de La Molina y como consecuencia a la evaluación determinar si es factible ampliarlo en 3 niveles más con el fin de darle un mejor uso, acondicionándola como tiendas comerciales en todos sus niveles. La principal teoría utilizada para evaluar la estructura y ampliarla son el análisis sísmico estático y dinámico teniendo en cuenta las cargas puntuales y distribuidas de la estructura para el estático y el espectro de Pseudo-aceleraciones para el dinámico de acuerdo a la normatividad vigente, también el modelamiento estructural en el programa ETABS con el que mediante el análisis del programa nos proporcionara los desplazamiento en la estructura y con estos resultados de acuerdo a la norma sísmica vigente podremos determinar las distorsiones en cada nivel siendo estos valores para que cumpla con la norma menores a 0.07. El tipo de investigación utilizado es básico, cuantitativo, explicativo y el diseño es no experimental, transversal y descriptivo. Es prospectiva pues trata de un diseño sísmico donde trabajaremos con valores proporcionados por el programa. De los resultados que se calcularon tanto en la estructura original como en la ampliación se determinó que el cambio de uso para la estructura original teniendo en cuenta el retiro de las cargas adicionales y la ampliación es factible ya que ningún valor en las torsiones fueron mayores al 0.07 propuesto en la norma. In the structural evaluation and extension levels for the change of use of the house of the elderly to shopping center in the district of La Molina, it is determined to be feasible as a commercial use to give a house the elderly with amendments necessary level of structure and expanding the same into 3 levels, it offers a potentially profitable business, thanks to the commercial area where it is located mayor Avenue Mall - Cuadra 5 to the approximate area of 700m2. Therefore, we have as a general objective to evaluate the structure of a house of the elderly for change of use to a commercial center in the district of La Molina and consequently to determine the feasibility assessment extend over 3 levels more in order to give better use, renovating as commercial shops at all levels. The main theory used to evaluate the structure and expand are static and dynamic seismic analysis considering point loads and distributed structure for static and pseudo-acceleration spectrum for dynamic according to regulations, also the structural modeling in ETABS program that by analyzing the program we provide the shift in the structure and the results according to current seismic code can determine distortions at each level being these values to comply with the norm under 0.07. The research used is basic, quantitative and explanatory design is not experimental, transversal and descriptive. It is a prospective for seismic design where work with values provided by the program. From the results that were calculated in both the original structure and the extension was determined that change of use for the original structure considering the withdrawal of additional charges and the expansion it is feasible because no value was higher by twisting 0.07 proposed in the standard.

No description available.

Seismic isolation systems are widely used to protect reinforced concrete (RC) structures against the effects of strong ground motions. After a magnitude 6.6 earthquake, the outpatient building of Lushan People’s hospital in China remained in good condition due to the seismic isolation technology, while the non-isolated older outpatient building nearby experienced major damage. The building provides a good opportunity to study and assess the contribution of isolation systems to seismic performance of RC structures. In the current research project, the isolated outpatient building was modelled and analyzed using computer software SAP2000. The post-yield behaviour of the structure was modelled by assigning multi-linear plastic links to frame objects. The rubber isolators were represented by rubber isolator link elements, assigned as a single joint element between the ground and the superstructure. The isolated structure was subjected to four earthquake records with increasing intensity. The performances of the isolated structure were compared with those of the fixed-base structures in terms of lateral inter-storey drifts, peak absolute floor accelerations, and residual drifts. The laminated rubber bearings, the high damping isolation devices, composed of rubber bearings and viscous dampers, and the hybrid isolation system of rubber bearings and friction pendulum bearings were analysed. The effectiveness of the three base isolation systems considered in enhancing structural performance was investigated. The results show the level of improvement attained in seismic response by each system. They also illustrate that the rubber bearings coupled with friction pendulum bearings produce the best drift control without causing excessive horizontal displacements at the base level and without adversely affecting floor accelerations.