Due to the high economic losses from the 1994 Northridge earthquake, Richard Riordan, the mayor of the City of Los Angeles, asked the Blue Ribbon Panel for Seismic Hazard Reduction to investigate the damage and economic loss.
Consequently, in 1995 the insurance and finance committee recommended that the City should develop standardized methods for evaluating and grading the seismic vulnerability of existing detached single family wood-frame dwellings. In 1998, the Applied Technology Council (ATC) was hired by the City of Los Angeles to develop seismic evaluation and grading procedures.
ATC-50 Retrofit Study
The ’94 Northridge Earthquake caused significant damage to homes. Observation of this damage by the City of Los Angeles revealed that much of it could have been prevented or significantly reduced by relatively inexpensive improvements in the structures.
In 2001, the City of Los Angeles selected our company to participate in the ATC-50 project. This was a Los Angeles Department of Building and Safety pilot project to test and validate the retrofit guidelines for single family homes.
Based on the results of a seismic assessment of homes participating in the project, our company first developed a proposed seismic retrofit scope of work and subsequently retrofitted these homes.
Following the completion of fifty retrofits (foundation bolting, cripple wall bracing, etc.), Avalin Seismic Construction Co. was asked to recommend to the L.A. Department of Building and Safety any changes that may improve the use of the Guidelines in the future in order to help homeowners whose homes are at risk from earthquakes.
ATC-50 Project Engineering Panel Members:
Mr. Timothy McCormick, Building Official, City of Santa Monica
Mr. John Coil, Thornton-Tomasetti/Coil & Welsh Engineers
Mr. Edward F. Diekmann, Consulting Structural Engineer
Ms. Susan Dowty, S. K. Ghosh Associates Inc.
Mr. Laurence M. Kornfield, Department of Building Inspection City and County of San Francisco
Dr. Onder Kustu, Oak Engineering
Mr. Doc X. Nghiem, Los Angeles Department of Public Works, Structural engineering Division
Mr. James Russell
Dr. Rubin Shepherd, Earthquake Damage Analysis Corp.
Mr. John G. Shipp, EQE International