The inventory of existing buildings in geographical areas subject to potential strong earthquake ground motion is enormous. The Seismic Risk division at MHP assesses the vulnerability of these buildings to assist clients in making informed decisions concerning valuable building assets. These due-diligence evaluations provide earthquake loss or Probable Maximum Loss (PML) estimates, and when appropriate suggest strengthening options, allowing the consideration of seismic risk of commercial assets in real estate transactions.
Considering both site hazards and building features, MHP’s experienced team of licensed engineers uses the latest tools and data available in evaluating building seismic risk. In addition to first hand experience gained through conducting post-earthquake evaluations following the San Fernando, Whittier, Loma Prieta, Northridge, and Nisqually earthquakes, this dedicated team has extensive in-house resources at their disposal. Built on the backbone of MHP’s evaluation of thousands of commercial properties these resources include: ATC 13, FEMA and ASTM E-2026 procedures and guidelines, numerous geologic hazard maps, city and agency seismic safety elements and on-line site hazard references. Significant in-house expertise in detailed, non-linear computer modeling of buildings enhances MHP’s ability to effectively predict building behavior and assess potential risks.
Led by Lance Kenyon and Brad Ferris, the combined experience and resources of MHP enables the firm to complete projects of any size and complexity, from small industrial and retail to high-rise and large portfolios, with capabilities that few firms can match.
The strength of MHP’s seismic risk group lies in the experience and knowledge developed while working on traditional design projects. The firm’s commitment to maintaining an active design emphasis allows those assessing building risks to gain continued insight into current design and construction practices. This interaction between the risk and design groups is a unique benefit that most firms providing seismic risk services cannot offer their clients. The design and building evaluation experience allows MHP engineers to develop and implement seismic strengthening programs that are efficient, appropriate and consistent with the desired performance objectives and risk tolerance of the client.
MULTI-FAMILY APARTMENT COMPLEX
Moreno Valley, California
Seismic Risk Evaluation-Level 2
TYPE
Multi-Family
STRUCTURE SPECIFICS
The project consisted of a 30-building, 400+ unit, low-rise multi-family apartment complex developed between 2005 and 2006.
CHALLENGES AND NEEDS
To meet the client’s due-diligence deadline, MHP generated a full-service report within five business days of receiving the request-for-proposal. Engineering services included site reconnaissance, inspection of 10% of dwelling units including attic spaces, document review and earthquake loss evaluation.
SCOPE OF SERVICE
Earthquake Loss Evaluation (Level 2) for acquisition. Scenario Expected Loss (SEL) and Scenario Upper Loss (SUL) results provided for the 475-Year return period event.
EVALUATION FINDINGS
Despite the high projected ground motion at the site, the loss estimates were reasonably low, due to the use of plywood shear walls with ductile detailing. The number and spatial arrangement of buildings permitted statistical averaging of the individual building SUL estimates to generate a lower, aggregate SUL loss estimate for the 30-building project.
Similar to this project, MHP completes dozens of seismic and structural risk evaluations of multi-family projects every year and has extensive experience dealing with the evaluation and structural repair and/or seismic strengthening of issues typical with these types of structures. These include: wood deterioration at stairs, balconies and siding; tuck-under parking configurations; inadequate shear resistance and/or shear transfer. MHP has also evaluated and designed numerous high-rise multi-family residential buildings.
