Hundreds of bridges are reconstructed or replaced every year. The AASHTO Load and Resistance Factor Design (LRFD) Bridge Design Specifications identify the minimum bridge design requirements, while the AASHTO LRFD Bridge Construction Specifications stipulate the bridge construction aspects. However, very limited information is available to guide the owner on how to approach deconstruction or the removal aspects of an existing bridge. The design and construction codes provide very little direction on demolition, and each state approaches this work differently.
Unintentional events during bridge demolition can result in bodily harm, project delays, traffic disruptions, and in some instances loss of life. In less than one year, two worker fatalities have occurred on two separate occurrences due to the collapse of a bridge structure while undergoing demolition. The first occurred in Orange County, CA in May of 2014; the second occurred in Cincinnati, OH in January 2015. While these events may be considered low probability, the outcomes are of high consequence. A recent technical report published by the Florida International University (FIU) Accelerated Bridge Construction University Transportation Center analyzed data received on this topic from 28 states. This analysis found that over the past 15 years, 25% of those states experienced an accidental incident (defined as an inadvertent event during demolition that could have led to a bridge collapse) and 25% of these events led to injury or loss of life. Further, 43% of those states surveyed experienced an event that led to an unintentional bridge collapse, half of which resulted in injury or loss of life. The project team extrapolated the data and estimates that nationally, there have been between 27 and 33 accidental incidents over the past 15 years. They also estimate that between 27 and 33 unintentional collapses have occurred over the past 15 years. Combined, these accidental incidents and unintentional collapses have resulted in 20 to 24 injuries and 8 to 10 fatalities. Clearly, there is an urgent need to understand the factors that contribute to these accidents. This need is supported by FIU’s findings that nearly half of states surveyed are seeking information on best practices related to the execution and administration of bridge demolition.
The objective of this synthesize is to document practices used by owners to manage and administer bridge demolition requirements within construction projects. This would include the methods of communicating project specific needs in the form of specifications, design details, stability requirements, review types, contractor responsibility, owner oversight, and acceptance.
Accomplishment of the goal will require, but not be limited to, the following tasks:
Task 1: Literature Search
Conduct a literature and project review of all relevant domestic projects to identify how demolition requirements are administered and specified by owners. Also document the different demolition requirements for project types based on project needs. At a minimum, review existing related research conducted through the NCHRP, Strategic Highway Research Program 2 (SHRP2), FHWA (and its pilot-project programs), and other national, state and pooled- fund research. In addition, the literature review should include interviews within the contracting community and a review of projects by owners, designers and contractors. Document the following as part of the literature review:
a. Owner’s level of oversight: from the perspective of risk and liability exposure; how do owners manage their level of oversight for bridge demolition activities?
b. Owner’s existing policies, specifications and special provisions to address bridge demolition activities
c. Typical bridge demolition submittals (drawings, calculations, sequence narratives, etc.) required by owners
d. Owner’s internal processes used to perform bridge demolition submittal reviews; including the level of review detail, reviewer(s) qualifications, and the types of acceptance
e. The level/degree of construction engineering oversight owners specify for their construction management engineer or field representatives for bridge demolition operations.
f. Existing processes and methods used by the owner’s construction management engineer or field representatives to conduct oversight during demolition and protocols used to initiate and cease demolition activities
g. Contractor feedback on the requirements, degree of review, and oversight implemented and administered by owners for bridge demolition related activities
Task 2: AASHTO Specifications
Review the current AASHTO LRFD Design and Construction Specifications to determine what guidance is provided on bridge demolition.
Task 3: Organize and summarize the information collected in Task 1 and Task 2
A survey and telephone interviews may be required to gather information for this synthesis. An 80% survey response rate is required.
Information Sources (Partial):
Garber, David. “Compilation of Results from Bridge Demolition DOT Survey” Final Report – Phase I, Florida International University Accelerated Bridge Construction University Transportation Center, Sept. 2016.
State DOT Standard Specifications, Bridge Manuals, Special Provisions, etc.
Jo Allen Gause
First Panel: November 14, 2017, Washington, DC
Teleconference with Consultant:
Hussam Z. "Sam" Fallaha, Florida DOT
Bruce V. Johnson, Oregon DOT
Malcolm T. Kerley, NXL
Kyle Kopper, Michigan DOT
Carin L. Roberts-Wollmann, Virginia Polytechnic Institute and State University
Carmen E. L. Swanwick, Utah DOT
Hoda Azari, FHWA
Nelson H. Gibson, Transportation Research Board