Banner for LabNotes
From Lab Notes
Contact Information
Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53726-2398
Phone: (608) 231-9200
Fax: (608) 231-9592
Email

 

You are here: FPL Home  / Information Products & Services  / Publications

Requested Product

Title: Performance-Based Seismic Retrofit of Soft-Story Woodframe Buildings

Source: Wood Design Focus, Volume 23, Number 4, 2013; pp. 3-9.

Author(s)Bahmani, P.; Lindt, J.W. van de; Pryor, S.E.; Mochizuki, G.L.; Gershfeld, M.; Rammer, D.; Tian, J.; Symans, D.

Publication Year: 2013  View PDF »

Category: Journal Articles
Associated Research Project(s):   FPL-4714-3B

Abstract: Soft-story woodframe buildings are recognizable by their large garage openings at the bottom story which are typically for parking and storage. In soft-story buildings the relative stiffness and strength of the soft-story, usually the bottom story, is significantly less than the upper stories due to the presence of large openings which reduce the available space for lateral force resisting system com-ponents such as shearwalls. This leads to large inter-story drifts and potential collapse at the ground floor, be-fore the upper stories inter-story experience significant drifts. In many cases the ground floor eccentricity, the distance between the center of rigidity and center of mass, of the soft-story is significant enough to develop considerable in-plane torsional moment in addition to the lateral force caused by the earthquake. A Performance Based Seismic Retrofit (PBSR) procedure can be used to effectively design retrofits that improve the performance of these at-risk buildings. This paper focuses on the PBSR methodology and the application and validation of this retrofit technique to a 4,000 sq. ft. full-scale four-story woodframe building tested at the University of California San Diego (UCSD) Network for Earthquake Engineering Simulation (NEES) outdoor shake table. The structure was retrofitted with various systems including a system that combined wood structural panel sheathing and Simpson Strong-Tie® Strong Frame® steel special moment frames. These types of retrofit techniques improve the performance of the soft-story building while accommodating existing architectural constraints of the building.

Keywords: stainless steel; nail withdrawal; National Design Specifications for Wood Construction (NDSr); nail bending yield strength; design

Publication Review Process: Formally Refereed

File size: 1,299 kb(s)

Date posted: 09/18/2014

This publication is also viewable on Treesearch:  view
RITS Product ID: 69023
Current FPL Scientist associated with this product
Rammer, Douglas R.
Research General Engineer
  

Additional items that might interest you
View the video celebrating FPL's 100 years of public service in 2010, from the producers of the Greatest Good....view

Research Highlights from FPL....view

Termite Eradication: A search for the Holy Grail.... view

Moisture Management in Residential Construction Series videos...view

Wood Floor Systems in Residential Construction Series videos....view
- FPL's Mission and Strategic Plan -

FPL's mission is to identify and conduct innovative wood and fiber utilization research that contributes to conservation and productivity of the forest resource, thereby sustaining forests, the economy, and quality of life. ... ..more »

- FPL Research Emphasis Areas -
Advanced Composites

As an integral part of the FPL mission, we improve the long-term sustainability of our Nation's forests by creating valuable composite products from biobased materials ... ..more »


Advanced Structures

The FPL has been in the forefront of wood-frame housing research since 1910 and has long been recognized as a world leader in such housing-related areas as engineered wood ... ..more »


Forest Biorefinery

We all know the compelling reasons that the United States needs to reduce its dependence on fossil fuels. Historically, the greatest increases in energy demand have been for transportation fuels ... ..more »


Nanotechnology

A leader in wood products research for over a century, the FPL is positioning itself to become the lead Federal research facility for the application of nanotechnology in forest products ... more »


Woody Biomass Utilization

Forests in the United States contain a substantial amount of small-diameter, overstocked, and underutilized material.FPL research projects are exploring the potential of the small-diameter ... ..more »