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There has been a growing concern in recent years about the effects of anthropogenic noise due to marine pile driving on underwater wildlife. Current guidelines for mitigating hydroacoustic effects associated with these events are based upon relatively simple transmission loss formulations. The advantage to these guidelines is that computing transmission loss using their prescribed methods is not labor intensive, but their disadvantage is that they may not take all variables into account. Because of this, it may be possible to improve transmission loss computations. To better-characterize marine pile driving sound transmission loss, a unique in-water instrumentation system was developed. This system consists of several hydrophone-equipped buoys that transmit sound data to a field team in real time via a wireless network. The sound data are also recorded onboard the buoys along with geospatial data and water temperature data at depth. Testing was conducted using this buoy system at various water-based pile driving sites throughout Florida and sound data were used to compute transmission loss as a function of distance from the sound sources to utilize data from these sites to improve the knowledge base associated with generating mitigation guidelines. This research found that the coefficients used to calculate the simplified transmission loss model were consistently above those recommended by the current set of guidelines. Future areas of improvement and additional testing are recommended to address the growing concern of anthropogenic noise on underwater wildlife species and the effects of underestimating the actual transmission losses.

CIVINS (Civilian Institutions) Thesis document, There has been a growing concern in recent years about the effects of anthropogenic noise due to marine pile driving on underwater wildlife. Current guidelines for mitigating hydroacoustic effects associated with these events are based upon relatively simple transmission loss formulations. The advantage to these guidelines is that computing transmission loss using their prescribed methods is not labor intensive, but their disadvantage is that they may not take all variables into account. Because of this, it may be possible to improve transmission loss computations. To better-characterize marine pile driving sound transmission loss, a unique in-water instrumentation system was developed. This system consists of several hydrophone-equipped buoys that transmit sound data to a field team in real time via a wireless network. The sound data are also recorded onboard the buoys along with geospatial data and water temperature data at depth. Testing was conducted using this buoy system at various water-based pile driving sites throughout Florida and sound data were used to compute transmission loss as a function of distance from the sound sources to utilize data from these sites to improve the knowledge base associated with generating mitigation guidelines. This research found that the coefficients used to calculate the simplified transmission loss model were consistently above those recommended by the current set of guidelines. Future areas of improvement and additional testing are recommended to address the growing concern of anthropogenic noise on underwater wildlife species and the effects of underestimating the actual transmission losses., CIVINS, CIVINS, CIVINS, Lieutenant, United States Navy, Approved for public release; distribution is unlimited.

FDOT Contract No. BDV34 977-04, The Florida Department of Transportation’s (FDOT) Asset Maintenance Contracting Program (AMC) was analyzed during this study to determine if it reduced cost or affected work quality when compared with more-traditional contracts. A survey was conducted of experts from industry, FDOT, and other DOTs to get their opinion on the AMC program. Results showed that if a program like Florida’s AMC is implemented properly, industry experts believe it can be successful. FDOT data from 2009-2015 were analyzed to determine quantitatively whether or not the AMC program was efficient. Meta-frontier ratios were developed between AM and non-AM contract types using data envelopment analysis (DEA). Results showed that AMCs consistently performed more efficiently than non-AMCs. Additionally, results showed that AMCs produced slightly significantly higher-quality work than non-AMCs. Subtle (administrative) cost effects were a relatively unimportant variable in the context of overall efficiency. Elimination of quality rating as an evaluative metric did not appear to affect results. In summary, the AMC program appears to be more efficient than more-traditional contracts.

A common method of government contracting is seeking the lowest bid that meets project specifications. While this assures that money is saved upfront, it may not ensure other project values, such as delivery time, ability to address unforeseen situations, and durability of the contract’s products. Alternative contracting methods based on performance measured by these values were first used by the Florida Department of Transportation (FDOT) in 2000. Since that time, improvements based on experience have led to more widespread use. While managers have confidence in the effectiveness of AMC, it has never been formally studied.

BDK75 977-35, Permeability is a measure of how well a porous medium conducts a fluid. For water, this property is called hydraulic conductivity, and it is important for projects that depend on properties of soil and strata, such as earthen dams, retention ponds, dewatering systems, hydraulic structures, wells, landfills, and many other engineered facilities that rely on hydraulic conductivity for their proper function. Hydraulic conductivity of soils can vary by many orders of magnitude, from 1x10-2 cm/sec for highly permeable sands to 1x10-7 cm/sec for practically impermeable clays.