Protecting wood frame buildings the goal of new earthquake grant to Caltech

PASADENA—The Federal Emergency Management Agency and California Office of Emergency Services announced today that $5.2 million in federal funds will be awarded to the California Institute of Technology (Caltech) for a three-year multi-university project to reduce the losses to woodframe construction in future earthquakes.

The project is funded by the federal disaster assistance Hazard Mitigation Grant Program for the 1994 Northridge earthquake. Combined with nonfederal matching funds, the total project budget will be $6.9 million.

The project, Earthquake Hazard Mitigation of Wood Frame Construction, is aimed at developing reliable and economical ways of improving wood frame building performance in earthquakes. The idea for the project originated after the 1994 Northridge earthquake, in which about half of the $40 billion property loss was incurred by wood frame construction.

Laboratory testing and analysis of wood frame buildings, and studies of their damage during the Northridge earthquake, will be conducted and applied to the tasks of improving building codes and standards, making insurance ratings and loss estimates more accurate, and training building designers, building inspectors, and contractors.

Professor of Civil Engineering John Hall of Caltech will be the project manager. According to Hall, "A serious look at the seismic vulnerability of wood frame construction is long overdue.

"In this project, we are concerned not only with the need to provide adequate earthquake resistance in new construction, but also reducing the high risks associated with existing structures such as the thousands of multi-residential wood buildings constructed over poorly braced parking garages," Hall said. "The multi-faceted nature of the project is designed to rapidly move into practice the techniques developed."

The multi-university program of tasks will be directed by California Universities for Research in Earthquake Engineering (CUREe). Professor James Beck of Caltech, the current CUREe president, stated that "although 99 percent of the residences in California are of wood frame construction, there has been surprisingly little research focused on improving their earthquake resistance."

The testing will be coordinated by Professor Frieder Seible of the University of California at San Diego, who commented that "the seismic response of wood frame buildings is largely controlled by the connections of the numerous pieces of material that make up a structure and by the quality and workmanship of these connections. Only large- or full-scale structural testing under accurately simulated seismic loads will be able to predict the performance of these connections, the wood structural members (such as two-by-four studs), and finally the overall building."

Professor Goetz Schierle of the University of Southern California School of Architecture will lead the investigations of buildings that went through the Northridge earthquake.

Schierle recently completed a study of the earthquake, concluding that newer buildings had more, not less damage, than older ones. He noted that "field studies of current woodframe construction have found that a third of the seismic features required by the Uniform Building Code are either flawed or completely missing in almost half the buildings. Architectural configurations have also become more adventuresome in recent years."

Structural engineer John Coil of Coil and Associates, Structural Engineers, in Tustin, and a past president of the Structural Engineers Association of California, is in charge of the implementation of the project's findings into building codes and standards and the practice of engineers and architects.

Coil commented, "Wood frame design has been based on construction experience and engineering assumptions that have never been fully tested. The best laboratory is a real earthquake, but short of that destructive way to test real buildings, we now have the capability to improve our building codes by means of realistic earthquake simulations of components of buildings and even multistory mock-ups of entire buildings.

Tom Tobin of Tobin Associates in Mill Valley will head up the element of the project devoted to economic aspects, for example the insurance and real-estate disclosure implications of the project's findings.

"A house is the single largest investment most of us make in our lifetime, and they contain our families and our futures. The CUREe-Caltech project will help home buyers and owners, as well as insurers and lenders, make economic decisions on a more accurate factual basis," Tobin said.

Jill Andrews of the Southern California Earthquake Center (SCEC), a National Science Foundation science and technology center devoted to earth sciences studies of earthquakes, will be in charge of the project's education and outreach effort.

She commented, "I'm particularly pleased to see federal funds promoting partnerships among organizations that traditionally have worked in parallel on the same basic earthquake problems but without always comparing notes. This project has been designed from the start to enable technical engineering findings to be translated into training for contractors, engineers, architects, building owners, and the public."

Kelly Cobeen, a structural engineer with GFDS Engineers in San Francisco has represented the Structural Engineers Association of California in national building code issues related to wood buildings. She commented that "The CUREe-Caltech wood frame construction project has the potential to revolutionize earthquake-resistant design of wood buildings, and as a result, revolutionize building codes and standards.

"Many long-standing design questions will be investigated, and improvements to codes and standards will be developed to address almost every aspect of resistance to earthquake forces. Results will include methods to improve the safety of building occupants as well as methods to quantify and limit the cost of earthquake damage."

According to James Russell, a building-codes consultant in Concord who is part of the project team, "This project offers an opportunity to calibrate the Uniform Building Code and the new nationwide International Building Code to be produced in the year 2000. We will be able to provide a scientific basis for proposing cost-effective changes to codes and standards."

Ken Luttrell, the president of the Structural Engineers Association of California (SEAOC), stated, "SEAOC is looking forward to serving as an advisor to the project, and to having its consulting-engineer members participate in the investigations. "SEAOC's membership includes many of the country's top structural engineers and university researchers in the seismic field. We expect this project to result in a significant impact on the performance of wood frame structural systems, and we are excited about contributing to this effort."

The senior consulting engineer advisor to the project is Dr. Gregg Brandow, president of Brandow and Johnston Associates, structural engineers in Los Angeles, who is also an adjunct professor of civil engineering at the University of Southern California.

According to Brandow, "The widespread economic losses caused by damage to wood buildings in the Northridge earthquake warrants this type of research effort, which will improve our engineering methods and technology based on an understanding of the realities of economics and construction."