Systematic Seismic Design for Manageable Loss in Wood-Framed Buildings

2009 ◽  
Vol 25 (4) ◽  
pp. 851-868 ◽  
Author(s):  
Shiling Pei ◽  
John W. van de Lindt

Light frame wood structures make up the vast majority of the residential building stock in the United States. Because of this, earthquake-induced losses for this category of building from a significant earthquake would have a substantial financial impact on the regional economy, as well as on the building owner. Current wood-framed structural design philosophy focuses only on life safety and only limits damage through implicit assumptions. The concept of loss-based seismic design is introduced in this paper with typical loss-based design statements explicitly formulated with the intent of addressing the concerns, e.g., financial loss, of the building end-user. The loss-based design procedure was established based on a loss estimation framework that relied on the existing concept of assembly-based vulnerability (ABV). With the help of an automated dynamic and loss analysis package developed for wood-framed structures (SAPWood™) at Colorado State University, loss-based seismic design for a typical North American single family residential building was conducted for several different explicitly stated loss targets. The results from the numerical examples showed that loss-based seismic design for wood-framed structures is a viable concept that can serve as an important step in the evolution of end-user oriented, performance-based seismic design (PBSD).

2009 ◽  
Vol 25 (3) ◽  
pp. 583-605 ◽  
Author(s):  
Wei Chiang Pang ◽  
David V. Rosowsky

This paper presents a direct displacement design (DDD) procedure that can be used for seismic design of multistory wood-framed structures. The proposed procedure is applicable to any pure shear deforming system. The design procedure is a promising design tool for performance-based seismic design since it allows consideration of multiple performance objectives (e.g., damage limitation, safety requirements) without requiring the engineer to perform a complex finite element or nonlinear time-history analysis of the complete structure. A simple procedure based on normalized modal analysis is used to convert the code-specified acceleration response spectrum into a set of interstory drift spectra. These spectra can be used to determine the minimum stiffness required for each floor based on the drift limit requirements. Specific shear walls can then be directly selected from a database of backbone curves. The procedure is illustrated on the design of two three-story ATC-63 archetype buildings, and the results are validated using nonlinear time-history analysis.


2006 ◽  
Vol 22 (1) ◽  
pp. 47-64 ◽  
Author(s):  
André Filiatrault ◽  
Robert E. Bachman ◽  
Michael G. Mahoney

This paper develops a performance-based seismic design procedure for pallet-type steel storage racks located in areas accessible to the public. Performance objectives for racks consistent with current building code procedures in the United States are defined. The paper focuses on collapse prevention of racks in their down-aisle direction under the Maximum Considered Earthquake (MCE) ground motions at the site. The down-aisle lateral load-resisting systems of racks are typically moment frames utilizing special proprietary beam-to-column moment-resisting connections that may result in large lateral displacements when subjected to MCE ground motions. A simple analytical model that captures the seismic behavior of racks in their down-aisle direction is proposed. The model assumes that the beams and columns remain elastic in the down-aisle direction and that all nonlinear behavior occurs in the beam-to-column connections and the moment-resisting connections between the base columns and support concrete slab. Therefore the behavior is based on the effective rotational stiffnesses developed by the beam-to-column connectors and column-to-slab connections that vary significantly with connection rotation. The model is validated against the results of shake-table tests conducted on full-scale racks under several ground-motion intensities. Finally, the model is incorporated in a displacement-based procedure to verify collapse prevention of racks in their down-aisle direction under the MCE.


2021 ◽  
pp. 875529302098196
Author(s):  
Siamak Sattar ◽  
Anne Hulsey ◽  
Garrett Hagen ◽  
Farzad Naeim ◽  
Steven McCabe

Performance-based seismic design (PBSD) has been recognized as a framework for designing new buildings in the United States in recent years. Various guidelines and standards have been developed to codify and document the implementation of PBSD, including “ Seismic Evaluation and Retrofit of Existing Buildings” (ASCE 41-17), the Tall Buildings Initiative’s Guidelines for Performance-Based Seismic Design of Tall Buildings (TBI Guidelines), and the Los Angeles Tall Buildings Structural Design Council’s An Alternative Procedure for Seismic Analysis and Design of Tall Buildings Located in the Los Angeles Region (LATBSDC Procedure). The main goal of these documents is to regularize the implementation of PBSD for practicing engineers. These documents were developed independently with experts from varying backgrounds and organizations and consequently have differences in several degrees from basic intent to the details of the implementation. As the main objective of PBSD is to ensure a specified building performance, these documents would be expected to provide similar recommendations for achieving a given performance objective for new buildings. This article provides a detailed comparison among each document’s implementation of PBSD for reinforced concrete buildings, with the goal of highlighting the differences among these documents and identifying provisions in which the designed building may achieve varied performance depending on the chosen standard/guideline. This comparison can help committees developing these documents to be aware of their differences, investigate the sources of their divergence, and bring these documents closer to common ground in future cycles.


Author(s):  
Michele Palermo ◽  
Vittoria Laghi ◽  
Stefano Silvestri ◽  
Giada Gasparini ◽  
Tomaso Trombetti

In the present work, a Performance-Based Seismic Design procedure applied to multi-storey frame structures with innovative hysteretic diagonal steel devices (called Crescent Shaped Braces or CSB) is introduced. CSBs are steel elements of peculiar geometrical shapes that can be adopted in frame buildings as enhanced hysteretic diagonal braces. Based on their "boomerang" configuration and placement inside the frame structure, they are characterized by a lateral stiffness uncoupled from the yield strength and, if properly inserted, by an overall symmetric hysteretic behavior with hardening response at large drifts, thus preventing from global structural instability due to second-order effects. The procedure here presented is intended to guide the structural engineer through all the steps of the design process, from the selection of the performance objectives to the preliminary sizing of the CSB devices, up to the final design configuration. The steps are described in detail through the development of an applicative example.


2011 ◽  
Vol 383-390 ◽  
pp. 6601-6607
Author(s):  
Xing Chong Chen ◽  
Xiu Shen Xia ◽  
Li Li Xing

Performance objectives and contents of resistance verification for high speed railway bridge are embodied and quantified based on the theory of performance-based seismic design. The resistance verification is proposed, which can control the damage under design earthquake and ensure safety of the pier under low-level earthquake. The simplified capacity spectra method for calculating displacement ductility factor is proposed by using strength reduction factor. The method for evaluating damage of RC bridge pier in high-level earthquake is presented by using maximum displacement and hysteretic energy. The proposed approach and procedures for performance-based seismic design are easily to implement. The performance-based seismic design procedure is demonstrated by using an example.


2020 ◽  
Vol 10 (11) ◽  
pp. 3942 ◽  
Author(s):  
Heungbae Gil ◽  
Kyoungbong Han ◽  
Junho Gong ◽  
Dooyong Cho

In areas of civil engineering, the resilient friction base isolator (R-FBI) system has been used due to its enhanced isolation performance under seismic excitations. However, because nonlinear behavior of the R-FBI should be reflected in seismic design, effective stiffness (Keff) of the R-FBI is uniformly applied at both peak ground acceleration (PGA) of 0.08 g and 0.154 g which use a multimodal response spectrum (RS) method analysis. For rational seismic design of bridges, it should be required to evaluate the dynamics of the R-FBI from in-field tests and to improve the seismic design procedure based on the performance level of the bridges. The objective of this study is to evaluate the dynamics of the R-FBI and to suggest the performance-based seismic design method for cable-supported bridges with the R-FBI. From the comparison between the experiments’ results and modal shape analyses, the modal shape analyses using primary (Ku) or infinite stiffness (fixed end) showed a great agreement with the experimental results compared to the application of Keff in the shape analysis. Additionally, the RS or nonlinear time history method analyses by the PGA levels should be applied by reflecting the dynamic characteristics of the R-FBI for the reasonable and efficient seismic design.


2021 ◽  
pp. 875529302110435
Author(s):  
Wael M Hassan ◽  
Janise Rodgers ◽  
Christopher Motter ◽  
John Thornley

Southcentral Alaska, the most populous region in Alaska, was violently shaken by a Mw 7.1 earthquake on 30 November 2018 at 8:29 am Alaska Standard Time. This was the largest magnitude earthquake in the United States close to a population center in over 50 years. The earthquake was 46 km deep, and the epicenter was 12 km north of Anchorage and 19 km west of Eagle River. The event affected some 400,000 residents, causing widespread damage in highways, nonstructural components, non-engineered and older buildings, and structures on poorly compacted fills. A few isolated serious injuries and partial collapses took place. Minor structural damage to code-conforming buildings was observed. A significant percentage of the structural damage was due to geotechnical failures. Building stock diversity allows use of the region as a large test bed to observe how local building practices affected earthquake damage levels. The prevailing peak ground acceleration (PGA) was 0.2–0.32 g, causing shaking intensity at most sites of 50%–60% of the ASCE 7-16 design basis earthquake acceleration. Thus, the seismic vulnerability of building stock in the region was not truly tested. Reinforced concrete buildings had minor structural damage, except in a few cases of shear wall and transfer girder shear cracking. Fiber-reinforced polymer (FRP)-retrofitted buildings performed satisfactorily. Concrete-masonry-unit (CMU) masonry buildings experienced serious structural damage in many cases, including relatively newer buildings. The earthquake caused widespread structural damage in non-engineered buildings (primarily wood and CMU masonry) that exist widely in the region, especially in Eagle River. Of these, non-engineered single-family wood buildings had the heaviest structural damage. No structural damage could be observed in steel buildings. The aftershock sequence, which included 7 M5+ and 50 M4+ events, exacerbated structural damage in all types of buildings. The present study is based on the EERI field reconnaissance mission conducted by the authors following the earthquake. Based on the observed damage and structural performance, seismic risk mitigation recommendations are suggested.


Author(s):  
Jordan Thompson ◽  
Moncef Krarti

Abstract In this report, a resiliency analysis is carried out to assess the energy, economic, and power outage survivability benefits of efficient and Net-Zero communities. The analysis addresses the appropriate steps to designing an energy-efficient and Net-Zero community using Phoenix, Arizona as a primary location for weather and utility inputs. A baseline home is established using International Energy Conservation Code (IECC) 2018 code requirements. Three occupancy levels are evaluated in BEopt to provide diversity in the community’s building stock. The loads from the baseline, energy-efficient optimum, and Net-Zero optimum single-family homes are utilized to determine energy use profiles for various residential community types using occupancy statistics for Phoenix. Then, REopt is used to determine the photovoltaic (PV) and battery storage system sizes necessary for the community to survive a 72-hour power outage. The baseline community requires a 544-kW PV system and 375-kW/1,564 kWh battery storage system to keep all electrical loads online during a 72-hour power outage. The energy-efficient community requires a 291-kW PV system and a 202-kW/820 kWh battery storage system while the Net-Zero community requires a 291-kW PV system and a 191-kW/880 kWh battery storage system. In this study, the economic analysis indicates that it is 43% more cost-effective to install a shared PV plus storage system than to install individual PV plus storage systems in an energy-efficient community. After analyzing the system sizes and costs required to survive various outage durations, it is found that only a 4% difference in net present cost exists between a system sized for a 24-hour outage and a 144-hour outage. In the event of a pandemic or an event that causes a community-wide lockdown, the energy-efficient community would only survive 6 hours out of a 72-hour power outage during a time where plug loads are increased by 50% due to added laptops, monitors, and other office electronics. Finally, a climate sensitivity analysis is conducted for efficient communities in Naperville, Illinois and Augusta, Maine. The analysis suggests that for a 72-hour power outage starting on the peak demand day and time of the year, the cost of resiliency is higher in climates with more heating and cooling needs as HVAC is consistently the largest load in a residential building.


1999 ◽  
Vol 15 (3) ◽  
pp. 435-461 ◽  
Author(s):  
Sutat Leelataviwat ◽  
Subhash C. Goel ◽  
Božidar Stojadinović

A new performance-based plastic design procedure for steel moment frames is presented in this paper. The role of plastic analysis in seismic design of structures is illustrated. The ultimate design base shear for plastic analysis is derived by using the input energy from the design pseudo-velocity spectrum, a pre-selected yield mechanism, and an ultimate target drift. The proposed design procedure eliminates the need for a drift check after the structure is designed for strength as is done in the current design practice. Also, there is no need for response modification factors since the load deformation characteristics of the structure, including ductility and post-yield behavior, are explicitly used in calculating the design forces. The results of nonlinear static and nonlinear dynamic analyses of an example steel moment frame designed by the proposed method are presented and discussed. The implications of the new design procedure for future generation of seismic design codes are also discussed.


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