Vulnerability of mid-high rise commercial-residential buildings in the Florida Public Hurricane Loss Model

In its first stage the Florida Public Hurricane Loss Model (FPHLM) was developed to predict expected losses due to hurricane activity and to evaluate mitigation measures for single-family residential buildings. The FPHLM was certified by the state of Florida, and was recently extended to include commercial-residential buildings, classified as low rise (1 to 3 stories) and mid-high rise structures (4 or more stories). The challenges that these types of buildings present led the research team, composed of experts in the field of atmospheric science, civil engineering, actuarial and computer science, to create new approaches for both cases. In this paper the method to calculate the vulnerabilities of mid-high rise buildings is described and the preliminary results are introduced. Unlike single-family residential buildings, mid-high rise buildings have a high variability not reducible to a few typical cases. To deal with this problem a modular approach is proposed that estimates the vulnerabilities of individual apartment units. The modules cover most usual apartment types, and are combined to represent whole buildings. Thus, buildings with any number of stories or units per floor can be modeled by aggregating the corresponding damage per unit. 2 MID-HIGH RISE BUILDINGS SURVEY Although previous surveys of Florida’s singlefamily residential buildings have been performed (Intrarisk 2002, Zhang 2003), the authors of this paper have carried out one of the first attempts to describe the mid-high rise buildings’ constructive features using information from property appraiser’s databases all over the state of Florida. This information is essential to identify the most representative cases that are worth being modeled. Even though the results have been shown elsewhere (Pita et al. 2008), a summary is reproduced here to describe the midhigh rise models selection process. The importance of any building type in the building stock is related to both its quantity and its value (Pielke and Landsea, 1998, 2008). Figure 1 shows a comparison of the relatives quantity and value of low-rise (LR-C) and mid-high rise (MH-R) buildings among condominiums (data for apartment buildings is incomplete). 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% Low rise condos Mid-high rise condos Cost of Buildings