Forensic Engineering (2007)

More than a millennium before Columbus landed on the new world, the Maya developed a culture with advanced scientific and technological capabilities. These distinctive scientific breakthroughs were developed without diffusion from outside cultures. For hundreds of years, amazing technical accomplishments of America's first civil engineers were jealously hidden by the mysterious rainforest. Recently the accomplishments of Maya Engineers have been uncovered by a new breed of forensic engineers. This new discipline of "archaeo-engineering" has uncovered evidence of the works created by ingenious Maya engineers. Archaeologists consider the Maya to be a Stone Age culture because they did not use bronze or iron implements. However, these professionals lack the technical training required to comprehend the sophistication of the Maya sciences which enabled them to create their technologically advanced society. This paper will concentrate on three salient Maya engineering breakthroughs that were combined synergistically to construct an engineering landmark of the ancient world. These Maya engineering landmarks have recently been uncovered by Archaeo-engineers using digital tools, state-of-the art computer modeling and simulation, and forensic engineering techniques developed by the Council for Forensic Engineering of the ASCE.

The number of tornadoes reported annually in the U.S. has steadily increased over the past 50 years. In recent times, the U.S. has averaged 1,200 tornadoes per year. The central portion of the U.S. has been dubbed "tornado alley" since more tornadoes have formed in this area than the rest of the world. The unique combination of warm gulf air, cold artic air, and western mountain ranges creates conditions that produce frequent supercell thunderstorms — which will on occasion spawn strong tornadoes. Given the relatively large quantity of strong tornadoes in recent years, structural engineers have had many opportunities to investigate building damage caused by these destructive weather phenomena. Prospects for building damage assessment will likely continue to increase in the near future. The purpose of this paper is to provide structural engineers with an understanding of basic damage assessment to buildings from tornado events. We will review how high wind forces and large hail from tornado events may damage a building, and delve into situations where the structural engineer must discern between damage caused by a tornado event and damage caused by other means. We will review several case studies depicting damage (both obvious and not-so-obvious) from recent tornadoes, including a 2004 tornado that killed 8 people in Utica and Joliet, Illinois, and a tornado that struck Caruthersville, Missouri in 2006. We will also review how tornadoes are classified per the Fujita system, and how this system was revised to the Enhanced Fujita scale beginning in February, 2007. The author has been involved with damage assessment to a variety of structures that were subjected to forces from recent tornadoes in the central portion of the U.S. (i.e., Midwest). The author has also performed hundreds of investigations from storm damage, including tornadoes, hurricanes, hail, rain, and snow events over the past several years.

In the wake of a widespread catastrophic event, such as a hurricane, earthquake, tornado, or flood, structural engineers are often engaged to perform initial damage assessments. While the task may range from a single residence to a community containing several hundred structures, each and every assessment must be accurate, complete and delivered in a timely. To meet this need the engineer is faced with establishing a thorough and efficient assessment process that is also cost effective. This paper proposes protocols that can be used when conducting multi-structure damage assessments in response to catastrophic events that meet these needs. The American Society of Civil Engineers has published ASCE 11-99, Guideline for Structural Condition Assessment of Existing Buildings (Guideline). This document has been developed as a guideline for the completion of a structural condition assessment and outlines recommended procedures for the evaluation of an existing structure. The procedures and guidelines within the Guideline however, are slanted toward the single structure assessment with the intention of determining structural adequacy with regards to increased loading, change in use, etc. The multi-structure assessment and the damage assessment are both only briefly alluded to within the text of the Guideline. The intention of this paper is to expand upon this particular type of assessment and offer practices which have proven repeatedly successful. The Guideline proposes a multi-step procedure of progressively more detailed and labor intensive assessment tasks. Specifically, the Preliminary Assessment and Evaluation is based on a cursory site inspection and review of available documentation while the Detailed Assessment and Evaluation is based on a more thorough site inspection as well as the introduction of possible material testing and component evaluation. At each step, the engineer is to identify whether sufficient information has already been obtained or if further investigation or testing is required. In addition, a Cost-Impact Study is recommended to determine the economic feasibility of continued testing, assessment, and evaluation of the subject structure. The format of this paper generally corresponds to the format of the Guideline. This has been done so the reader can easily follow both documents and determine the applicable portions for the particular assessment.

Hurricane Katrina made landfall on August 29, 2005 causing significant damage to the built environment including buildings, roads and bridges, utility distribution systems for electric power and water, waste water collection facilities, and vital communication networks. This paper details post-disaster field reconnaissance of the Gulf Coast immediately following Hurricane Katrina organized by MCEER. The objectives of the reconnaissance were to examine and document the impact of Hurricane Katrina from a multi-hazard perspective. More specifically, lessons learned from Hurricane Katrina are being evaluated to mitigate damage not only from future hurricanes, but also from other extreme events such as earthquakes or terrorist attacks. As an example, a multi-hazard objective of this mission was to identify similarities between damage typically observed after earthquakes and damage caused by Hurricane Katrina with the goal of identifying seismic design principles that could mitigate structural damage caused by wind and storm surge forces. Researchers observed extensive losses from nonstructural damage to cladding, windows, and roof-mounted equipment while the structural frame remained undamaged. In storm surge regions such as the Mississippi coast, however, structural damage was observed in buildings and bridges exposed to storm surge and impact from large storm surge debris such as barges, much of which relates to tsunami risk.

Ernest Shackleton, an early 20^th century Antarctic explorer, was best known for his leadership skills in the face of extreme hardship. After his ship, Endurance, was trapped in the icy waters of the Weddell Sea, he kept his entire crew alive for nearly 2 years. Many of his leadership principles can be applied to project management in our present time. This paper will explore the leadership traits that Shackleton embraced and will present a case study of junior level civil engineering students' responses to a video of the Shackleton saga. The paper will contrast Shackleton's leadership with that of another explorer of his time, Vilhjalmur Stefansson. It will also look historically back to Old Testament biblical times and compare both Shackleton and Stefansson to the leadership characteristics of both Moses and King David. Finally, two present day engineering case studies will be reviewed which show the complexity and results of being a leader, specifically a project manager, for taking responsibility and doing the right thing.

The process of excavating for a new building foundation, especially in urban settings, can often result in damage to adjacent buildings. In some cases, the damage can be severe, resulting in the need to temporarily vacate a building and even causing a partial collapse. The consequences can include injuries and loss of life, extensive property damage, construction delays, and expensive litigation. Even in cases of minor damage, the resulting insurance and legal issues can be expensive and distracting. Therefore it is advisable that the engineer of record (EOR) do all within his/her control to help prevent such accidents from occurring. Many of the failures that have occurred are preventable, at little or no added cost, with just the application of some common sense principles. This paper identifies problematic building types and soil conditions, provides preventative recommendations, suggests ways that the engineer of record can better protect his/her clients and himself/herself, and discusses strategies for dealing with buildings that are exhibiting distress. It also discusses the roles and responsibilities of the geotechnical engineer, the structural engineer, and the underpinning engineer.

The concept of spatially-tiered reconnaissance has been introduced as a method of providing increasingly detailed levels of analysis in post-disaster situations. Remotely sensed data is becoming more widely available on a systematic basis following natural disasters at various spatial, spectral and temporal resolutions. Depending on these resolutions, each dataset is capable of providing different levels of information. Figure 1 illustrates the three tiers that are used within spatially-tiered reconnaissance — Tier 1 (Regional), Tier 2 (Neighborhood), and Tier 3 (Per building), using storm surge damage sustained after Hurricane Katrina as an example.

The automated comparison of before-and-after remote-sensing imagery provides an effective means for rapid and widespread assessment of windstorm damage to individual buildings. The development of automated damage-assessment algorithms involves the classification of building damage signatures from a remote-sensing perspective, the identification of corresponding temporal change metrics, and the correlation of remote-sensing change signatures with actual field-based damage observations. Hurricanes Charley (August 2004) and Ivan (September 2004) marked the first major hurricanes for which high-resolution satellite images were available. These storms provided an exceptional set of before-and- after images. Investigators from Texas Tech University and ImageCat, Inc. obtained temporal satellite image sequences and performed associated ground-truthing damage surveys for these major hurricanes. This paper chronicles the use of the before-and-after hurricane imagery to develop remote-sensing-based damage scales for various building inventories; the correlation of remote-sensing damage metrics with field-based damage investigations; and the progress in automated damage assessment using temporal image sequences.