Journal of Performance of Constructed Facilities

This paper reviews the state of the art in the use of forensic engineering and failure case studies in civil engineering education. The study of engineering failures can offer students valuable insights into associated technical, ethical, and professional issues. Lessons learned from failures have substantially affected civil engineering practice. For the student, study of these cases can help place design and analysis procedures into historical context and reinforce the necessity of lifelong learning. Three approaches for bringing forensics and failure case studies into the civil engineering curriculum are discussed in this paper. These are stand-alone forensic engineering or failure case study courses, capstone design projects, and integration of case studies into the curriculum. Some of the cases have been developed and used in courses at the United States Military Academy and the Univ. of Alabama at Birmingham, as well as at other institutions. Finally, the writers have tried to assemble many of the known sources of material, including books, technical papers, and magazine articles, videos, Web sites, prepared PowerPoint presentations, and television programs.

The failure of two reinforced concrete structures is recounted, one involving a warehouse structure and the other an offshore platform base structure. Design details and factors leading to the collapses are identified and discussed. The structures were subsequently analyzed using nonlinear finite-element analysis procedures, taking into account relevant second-order behavior models. The analyses provided an accurate assessment of the load capacities and failure modes observed, as well as meaningful insights into the underlying behavior mechanisms and factors leading to the failures. This paper supports the view that nonlinear analysis techniques have become useful everyday tools for design office applications, particularly in forensic work, and also gives evidence suggesting that errors in the design of modern structures can be potentially more catastrophic than in the past, and that advanced assessment techniques will assume increased importance as a result.

Two manufactured metal building warehouses loaded with agricultural products failed in service. Inspection revealed considerable damage to the structure and the foundation. The building owner filed suit against the building supplier, the building erector, and the soils testing laboratory whose engineer had designed the foundation. The agricultural product imposed substantial outward lateral pressures on the walls of the structures. Review of the available design documents indicated that these loads had not been accounted for in design. A structural analysis revealed that elements of the structure were underdesigned for the agricultural product loads. In addition, the foundation did not have any slab reinforcement to resist the loads. To prevent similar failures, these loads must be accounted for in design. The steel structure design and foundation design were both deficient. A contributing factor was the lack of communication between the designer of the structure and the designer of the foundation, due to the lack of a single engineer of record to take responsibility for the buildings.

Workable special protection methods to prevent lightning damage to equipment and possible harm to associated working personnel are presented. This document covers protection methods for ground potential rise, isolation, shielding, and grounding from lightning. Be warned: Protecting a structure from lightning does very little to protect the equipment within that structure, and the housed equipment is normally worth many times the value of the structure. Lightning damage to equipment results in losses exceeding twenty-six billion dollars annually in North America and nearly three times that worldwide, with more than 150 strikes per second. Insurance payout resulting from lightning damage accounts for approximately 6.5% of all property and casualty claims. Ironically, nearly all lightning damage to equipment can be prevented.

Florida, which is one of the most storm-prone states in the United States, experienced several major hurricanes such as Andrew, Georges, Earl, and Opal in the last decade. The tremendous population growth in the Florida coastal region has increased the volume of coastal residential construction, enhancing the possibility of storm damage. After a storm is over, the Florida Department of Environmental Protection and local government personnel identify the amount of damage sustained by structures and follow the Federal Emergency Management Agency’s “50% substantial damage rule” to determine the repairability of structures on a case-by-case basis. This process requires a substantial amount of personnel time and effort, often delaying the permitting process. Currently, there is no convenient decision-making tool to quickly assess damaged structures after a storm and place them in “repair” or “rebuild” categories. In this study, decision matrices were developed based on the current construction cost data, identified damage levels, factors affecting decision making, and current requirements of Florida Statutes, Chapter 161, the Florida Department of Natural Resources, the Florida Department of Community Affairs, and the Florida Department of Environmental Protection. Decision-making software was developed that can be used in the field to quickly classify structures for rebuildability and to provide approximate repair costs.