Making the Case for Improved Structural Design: Tornado Outbreaks of 2011

Abstract

A total of 1,625 tornadoes occurred in the United States in 2011, resulting in economic losses that exceeded $25 billion. Two tornado outbreaks stand out because they caused more than half of those losses. The tornadoes that cut through Tuscaloosa, Alabama, on April 27 and Joplin, Missouri, on May 22 were responsible for a combined 223 fatalities and more than 13,000 damaged buildings in the two cities. Although the economic losses associated with tornado damage are well documented, the writers argue that the overall impact should encompass longer term, broader considerations such as the social disruption and psychological effects that impact communities. This paper examines observations by tornado damage assessment teams led by the first author in these two medium-sized cities and suggests that the evolution of building codes and past approaches to construction have led to conditions that made this extent of damage possible. The authors outline a multidisciplinary path forward that incorporates engineering research and social and economic studies into a new design paradigm leading to building code changes and social practices that will improve resistance and mitigate future losses at a community level from tornadoes.

A Monte Carlo model for estimating tornado impacts

“…Mann et al, 2014;IPCC, 2014). For example, the implementation of tornado safe rooms or tornado shelters and adaption of building codes may enhance tornado survivability and decrease disaster consequences in tornado-prone areas (Simmons and Sutter, 2007;Prevatt et al, 2012;Simmons et al, 2015). Restricting new development near uncertain and dynamic floodplains (Patterson and Doyle, 2009), seismically and volcanically active areas (Strader et al, 2015b), locations prone to wildfires (Bryant and Westerling, 2014;Mann et al, 2014), regions subject to tropical cyclone hazards and sea-level rise (Pielke et al, 2008;Maloney and Preston, 2014) may reduce disaster losses.…”

Comparison of two methods of near-surface wind speed estimation in the 22 May, 2011 Joplin, Missouri Tornado

“…From an engineering perspective, estimated near-surface wind speeds are used in the design of nuclear power plants, safe rooms and storm shelters. Recent philosophies have also stressed including commercial and residential structures in tornado-based design (Kuligowski et al, 2014;Prevatt et al, 2012c;van de Lindt et al, 2012). Increased knowledge of the near-surface wind fields in tornadoes would provide an engineering basis for design, leading to more robust structural systems (Prevatt et al, 2012c), and improved buildings codes and standards (Amini and van de Lindt, 2013).…”

“…Recent philosophies have also stressed including commercial and residential structures in tornado-based design (Kuligowski et al, 2014;Prevatt et al, 2012c;van de Lindt et al, 2012). Increased knowledge of the near-surface wind fields in tornadoes would provide an engineering basis for design, leading to more robust structural systems (Prevatt et al, 2012c), and improved buildings codes and standards (Amini and van de Lindt, 2013). From a meteorological perspective, a better understanding of the near-surface wind field is important for understanding possible changes in the tornado record due to climate change and assessing likelihood of tornadoes and their intensity given certain atmospheric conditions (Brooks, 2013).…”

Development of Empirically-Based Fragilities of Residential Damage in the 2011 Joplin, Missouri, Tornado

“…Failures in wood-frame structures during extreme wind events are commonly encountered because most wood-frame residential structures are built to prescriptive requirements that nominally provide life safety during a design wind event, which for most of the US is 115 mph (ASCE, 2010). Prevention of damage during tornadoes has typically not been considered, however recent work has highlighted the need for a new design paradigm for tornadoes that would include both life safety and reduced damage as objectives in the design Prevatt, D. O., van de Lindt et al, 2012). For such a paradigm, it is important to determine an acceptable wind speed for tornado design.…”