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Addressing Grand Challenges

7/1/2015

In 2008, the National Academy of Engineering (NAE) published "Grand Challenges for Engineering," which identified 14 complex and broadly based problems for which engineering solutions are needed in the twenty-first century to sustain civilization's continued advancement while improving the quality of life for all. The challenge most closely aligned with ACI's mission is related to restoring and improving our urban infrastructure.

As a basis for evaluating urban infrastructure, the Infrastructure Report Card issued every 4 years by the American Society of Civil Engineers (ASCE) is frequently cited. This work focuses on the infrastructure systems (such as transportation, power, water, and wastewater) that are essential for modern societies. To date, failures of these systems are infrequent, but catastrophic disruptions, such as the widespread damage to multiple infrastructure systems across broad regions of the United States during Hurricanes Katrina (2005) and Sandy (2012), have highlighted the need to increase the robustness of our infrastructure systems and promote sustainability and resilience during the original design.

In discussing these issues, it is far easier to focus on the response of an infrastructure system or a component of a system than to address the impact that a failure has on the lives of the people affected. For example, hundreds of thousands of people lost their homes in the April earthquake in Nepal. From afar, it would be easy to blame the damage on traditional, but vulnerable, forms of construction, such as unreinforced brick and stone masonry. Modern forms of construction could have protected many of the occupants and greatly shortened the recovery process, but modern reinforced masonry and/or concrete construction is not economically viable in many places around the world, including the rural communities in Nepal.

Closer to home, floods destroyed thousands of homes in central Texas over the Memorial Day holiday weekend in May. Adherence to modern building codes and construction methods was not sufficient to protect the occupants of these structures. The region is prone to flash flooding, and San Marcos—one of the communities most severely affected—is the fastest-growing city in the United States. As a result, population density is increasing rapidly and the inherent risks of natural disasters are not reflected in the design standards.

It is my hope that ACI can take a more active role in developing design guidelines for safe, resilient, sustainable, and, most importantly, affordable housing worldwide. This vision will only be successful if the incremental cost of improving the inherent safety is modest in proportion to the overall cost of construction. Especially when designing to withstand rare events—those with return periods of more than 100 years—the initial cost will govern the construction decisions. But, if well-conceived and economical options are available, and if these options do not deviate significantly from standard construction practices in the area, the likelihood of adoption is much higher.

A perfect example is the concept of above-ground, in-residence storm shelters, which was developed at Texas Tech University, and forms the basis for current FEMA recommendations. These safe rooms are designed to resist 250 mph (400 km/h) winds and tornado-generated projectiles. The designs are also consistent with wood-frame construction, which is used for home construction across the United States.

ACI Committee 314, Simplified Design of Concrete Buildings, has established a similar framework for earthquake-resistant design of low-rise buildings. The 314 guide is based on IPS-1, Essential Requirements for Reinforced Concrete Buildings, which was originally developed in Colombia and addresses types of construction that are frequently used in Latin America.

As ACI increases its ties to international chapters and expands global outreach efforts, the possibility of reducing risks to natural disasters is greatly enhanced. Developing sustainable, resilient, and affordable options for residential construction is a grand challenge—and one that we should undertake.

Sharon L. Wood