47.5 MB - The Whole Building Design Guide

Figure 4-37:Back Bay Fire Company#34.4.6 Structural SystemsConcrete and reinforced masonry have traditionally been the mostrobust structural systems for hurricane-prone areas, since theyhave a much higher reserve structural strength than other systems.During high-wind conditions, the added weight of the concretehelps counteract the uplift forces, while the mass and depth of concreteand masonry walls provides reserve structural strength thatprevents the walls from being breached during high winds andflood conditions. However, with precast concrete elements, attentionto design and construction of connections is important. Thiswas generally confirmed during Hurricane Katrina.The Jackson County EOC, located in Pascagoula, Mississippi, wasbuilt in 1977 and is an example of a structurally well-designed facility.The structure is composed of cast-in-place concrete, andperformed remarkably well (see Figure 4-38). Although the EOCis located on the second floor of the building, water only camewithin 1 inch of the ground floor, which is approximately 4 to 5feet above the surrounding grade. Other structural systems provento be resistant to flood and wind loads are steel or concrete framesthat are covered with precast concrete panels. These systems havevery high reserve capacities that perform extremely well duringhigh winds and storm surges.4-54 OBSERVATIONS ON THE PERFORMANCE OF CRITICAL FACILITIES