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Retrofitting wood-frame soft-story structures

Structural engineers across California will meet in Los Angeles Tuesday to discuss buildings at risk of damage in earthquakes. One topic will be the problem of wood-frame apartment buildings that have a “soft story,” or a wobbly bottom floor. One such apartment complex collapsed during the 1994 Northridge earthquake, killing 16 people.

During an earthquake | Three examples of soft-story buildings | Strengthening soft-story structures

The lower-floor walls of a soft-story structure are weak and can collapse in an earthquake.

Common soft-story buildings include apartments and condominiums with ground floor parking or large storefronts. The inventory proposed by LaBonge would identify wood-frame soft-story residential buildings that are at least two stories tall with at least five residential units built before 1978.

New columns, walls or steel braces are common ways to strengthen the structure.

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