At 300 feet tall, 100 Wilshire is the tallest building in Santa Monica and consists of a 21-story, 255,000-square-foot cast-in-place concrete office tower over three levels of subterranean parking. The building was constructed in 1970 and therefore subject to the requirements of the City of Santa Monica Non-Ductile Concrete (NDC) seismic ordinance. An initial linear evaluation was completed which indicated substantial strengthening was needed to satisfy the NDC Ordinance requirements.

Recognizing the significant impacts to business operations that the strengthening would entail, MHP recommended further in-depth study to determine if reduced strengthening could be justified.

The in-depth study included state-of-the-art ASCE 41 performance-based non-linear response history analysis, in-situ material testing, as-built condition verification, and refinement of site seismic hazard through detailed geotechnical studies. MHP assembled a team to complete the additional studies and refinements.

Ultimately, as a result of MHP and the team’s efforts, the building was signed off as compliant in 2022 with no strengthening necessary.

Awards

• 2023 SEAOSC Structural Engineering Excellence – Retrofit/Alteration – Award of Merit

250,000 Sq. Ft.

Douglas Emmett Builders

Seismic Evaluation