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Over the last 15 years, microbially induced calcite precipitation (MICP) has emerged as a possible solution to mitigate coastal erosion. To date, most MICP soil treatments that have been studied involve column injection using a pump. In recent years, MICP application through surface percolation has gained traction as an alternative technique, but data using this technique are limited. More recently, a new treatment recipe/technique was developed, and this technique was termed bioslurry. Like most MICP studies, research with bioslurry has concentrated on the column injection method, and surface percolation has received very limited attention. This paper discusses the treatment of Florida beach sand by surface percolating bioslurry. Researchers experimented with variations of the bioslurry recipe to optimize erosion resistance, which was assessed using a pocket erodometer combined with physical measurements. In addition, treated specimen morphology was preliminarily examined using X-ray diffraction and scanning electron microscopy. Results showed that erosion resistance was maximized when 15% to 25% of the specimens' pore volumes were filled with bioslurry and that this erosion resistance may be sufficient to withstand worst-case storm events after only one treatment. In addition, previous researchers always used a relatively long (i.e., ∼12 h) stir time when preparing bioslurry. Results presented here show that it may be possible to produce comparable data with much shorter stir times (i.e., 1 to 2 h). [ABSTRACT FROM AUTHOR]

Since the Ronan Point collapse in the UK in 1968, the progressive collapse analysis of residential buildings has gradually drawn the attention of civil engineers and the scientific community. Recent advances in computer science and the development of new numerical methodologies allow us to perform high-fidelity collapse simulations. This paper assesses different scenarios that could have hypothetically caused the collapse of the Champlain Tower South Condo in Surfside, Florida, in 2021, one of the most catastrophic progressive collapse events that has ever occurred. The collapse analysis was performed using the latest developments in the Applied Element Method (AEM). A high-fidelity numerical model of the building was developed according to the actual structural drawings. Several different collapse hypotheses were examined, considering both column failures and degradation scenarios. The analyses showed that the failure of deep beams at the pool deck level, directly connected to the perimeter columns of the building, could have led to the columns' failure and subsequent collapse of the eastern wing of the building. The simulated scenario highlights the different stages of the collapse sequence and appears to be consistent with what can be observed in the footage of the actual collapse. To improve the performance of the structure against progressive collapse, two modifications to the original design of the building were introduced. From the analyses, it was found that disconnecting the pool deck beam from the perimeter columns could have been effective in preventing the local collapse of the pool deck slab from propagating to the rest of the building. Moreover, these analyses indicate that enhancing the torsional strength and stiffness of the core could have prevented the collapse of the eastern part of the building, given the assumptions and initiation scenarios considered. Building catastrophic collapses can cause significant lives and economic losses. Poor design and maintenance, in combination with aging, will more likely increase, in the next years, the number of buildings potentially vulnerable to the risk of collapse, due to either seismic, accidental, or degradation actions. This research focuses on the analysis of the Champlain Tower South condo collapse, which occurred in Surfside, Florida, in 2021. Different hypothetical collapse scenarios were simulated, comparing the analysis results with the actual evidence of the collapse. The analyses have shown that the degradation of the pool deck slab, due to corrosion, may have contributed to the collapse of the building. Finally, two different minor revisions of the original design of the building were analyzed to reduce the risk of failure and understand how the collapse of similar residential buildings could be prevented. [ABSTRACT FROM AUTHOR]

Even with the continuous development of coating technologies, coating systems are susceptible to corrosion-induced premature failures and unable to meet the anticipated service life. Coating premature failures will negatively impact the safety, integrity, and longevity of steel bridge structural elements. The advancement of the data analytics approach (e.g., machine learning) offers an opportunity to leverage the wealth of historical bridge inspection and maintenance data collected by Departments of Transportation to evaluate coating conditions of steel bridges effectively and efficiently. This paper focuses on presenting a data-driven study that analyzes the conditions of coating systems of steel bridges in the state of Florida. Three machine learning algorithms were used in developing models that can be used to analyze steel bridge coating conditions based on data collected from the Bridge Management System of the Florida Department of Transportation. The result showed that the machine learning–based models were able to effectively predict steel bridge coating conditions. The k -nearest neighbor (KNN) regression algorithm offered the best performance. Although the approach was currently applied to the steel bridges of Florida, it can be easily replicable for similar data sets from other states. The research contributes to the body of knowledge by offering a data-driven understanding of coating performance of steel bridge elements. The research has the potential to offer a valuable decision-making tool for transportation agencies to effectively and easily analyze or predict steel bridge coating conditions. [ABSTRACT FROM AUTHOR]

Rock coring is an essential method of geotechnical site characterization for foundations supported by rock, in which three possible phases of operation exist: inefficient, optimized, and destructive. When operating within the optimized phase, core recoveries and the rock quality designation reflect the strata encountered. However, the optimized phase is rarely achieved in practice, leading to deficiencies in strength assessment and geotechnical site characterization. This paper identifies the operational limits that separate each phase of rock coring by using measuring while drilling (MWD) and quantifies the increased energy that results from an inadequate depth of cut (Phase 1), the effects of breaking rock particles into smaller sizes, and the damage that occurs to core specimens from increased frictional resistance (Phase 3), as well as the effect rock strength and bit geometry have on mechanical efficiency. Drilling parameter interdependencies are discussed and detailed guidelines to assess rock strength in situ via MWD are provided. Finally, recommended coring guidelines are established through MWD which optimize the quantity and quality of strength assessments collected to improve geotechnical site characterization. [ABSTRACT FROM AUTHOR]

A calibrated flow rating equation is often used to determine the flow rate through a hydraulic structure as a convenient and relatively inexpensive method to avoid the difficulties of direct discharge measurements in an open channel. In South Florida, there are hundreds of gated culverts, where accurate and quick estimation of discharge in real time is critical for effective water resource management. Flow through culverts under various conditions and geometries has been studied extensively; however, studies of stage-discharge relationships through gate-controlled culverts are rare and, to the authors' knowledge, not discussed in any open-channel hydraulics books, relevant journals, or design manuals. In this paper, two approaches to improve the stage-discharge relationships at gated culverts are presented, and case studies demonstrate their successful and cost-effective use: first, the application of computational fluid dynamics (CFD) for flow data simulation to supplement field measurements to resolve data limitations and, second, the application of dimensional analysis to improve gated-culvert rating equations. The proposed nondimensional flow rating approach is useful for data planning and consistency testing of hybrid data (field flow data and CFD results) and reduces the flow types occurring at a culvert, making the flow classification less complex while maintaining reasonable rating accuracy within 6% of field flow measurements. [ABSTRACT FROM AUTHOR]

This paper presents a case study of a bridge constructed under adverse conditions in rural Florida. The major challenges facing the contractor were clearly identified through analysis. The bridge was constructed by an established, experienced bridge contractor that faced many daunting challenges in the construction of the bridge foundation, ranging from overdesign to the project manager managing his first construction project. However, the biggest challenge was unforeseen site conditions; namely, some of the most difficult clay imaginable through which to drive piles. These challenges forced the contractor into several tactical maneuvers. In sharing both the methods adapted by the contractor and the results of the adaptations, this paper quantifies for researchers and practitioners how a good contractor made sound, fundamental decisions to overcome severe challenges, improve productivity rates midproject, and eventually make the project a success. A seeming disaster early on, the project was eventually completed in less than the contract duration and at a sizable profit for the contractor. [ABSTRACT FROM AUTHOR]

The available literature indicates that pile side shear increases almost linearly with the logarithm of time elapsed after driving, sometimes described using a dimensionless setup factor. A test pile program conducted by the University of Florida measured side shear setup (SSS) for up to 4.7 years on five, 457-mm (18-in), square, prestressed, concrete piles driven into coastal plain soils at different sites. Dynamic tests performed during initial driving and two restrikes measured short-term SSS. Osterberg cells, the first installed in driven concrete piles, measured long-term SSS starting within 24 h of driving and continuing with two to five additional, staged tests. Extensive instrumentation, including vibrating wire strain gauges, Marchetti total stress cells, and vibrating wire piezometers, divided the five piles into 28 segments by soil type with horizontal effective stress measurements for 18 of the segments. This paper describes the University of Florida test pile program and its results. A companion paper analyzes the test results and recommends procedures for implementing SSS in design. [ABSTRACT FROM AUTHOR]

This paper analyzes the results of a driven pile side shear setup (SSS) test program performed at the University of Florida and described in a companion paper. All pile segments showed SSS, with similar magnitudes in both cohesionless and cohesive soils, and irrespective of depth. Horizontal effective stresses increased after driving, but then stabilized as induced pore pressures dissipated. SSS continued long after pore pressure dissipation due to other aging effects. Pile load tests in all soil types, and standard penetration tests with torque measurement (SPT-T) in cohesive soils, confirmed the approximate semilog-linear time versus SSS behavior and the usefulness of the setup factor A. Staged (repeated) tests significantly increased SPT-T measurements, suggesting a reduction factor of 0.4 for SSS results measured by staged testing. We believe that engineers can now include SSS in routine design, using a minimum setup factor A=0.1 for soils similar to those tested, or higher if supported by dynamic or static pile tests, or by SPT-T predictor tests. Examples demonstrate a proposed SSS design method. [ABSTRACT FROM AUTHOR]

This paper examines an ethical dilemma related to the residential construction industry in Florida, where homes must be engineered to withstand extreme load conditions induced during high wind events. Overwhelming contractor pressure to minimize construction costs has resulted in the propagation of inadequate construction designs. The overwhelming adoption of these inadequate designs weakens the integrity of our industry, creating the impression that market pressure can influence our judgment despite conflicting results gained through engineering analysis. This paper illustrates the frailty of engineering judgment as a design fundamental. Further, it raises the question as to what extent professional engineers should substitute engineering judgment for concrete evidence such as numerical analysis or experimental verification. [ABSTRACT FROM AUTHOR]

This paper describes the development of a portable dynamic energy calibrator (PDEC) for mechanical Proctor compaction machines along with an analysis of system variance on a silty sand's (A-2-4) dry unit weights. The PDEC measures a rammer's kinetic energy delivered to the sample and the compressive energy retained in the sample. The monitoring system uses a photoelectric gate and impact force sensor attached to the machine. When the rammer mass is included, the system's impedance can be calculated. Next, 30 Florida Department of Transportation (FDOT)-approved machines throughout the state were tested, and summary statistics (i.e., mean, standard deviation, and so on) of the kinetic and compressive energies of the machines were found. Scatter plots of hammer kinetic energy along with sample energies allowed for identification of poorly functioning machines (e.g., low-impact energies or variations in mold support). Finally, a series of blind modified compaction tests were performed on A-2-4 soil at six labs at dry and wet of optimum. A regression analysis of the mean and variance of dry unit weight as a function of moisture content, kinetic energy, and sample energy was undertaken. Approximately 50% of the measured dry unit weight variance was associated with variance of kinetic energy, sample energy, or sample moisture. The other 50% of the variance was attributed to operator influence (i.e., sample preparation, lift thicknesses, moisture determination, and so on), which was not measured in this study. [ABSTRACT FROM AUTHOR]

Departments of transportation in the United States are under increasing pressure to accelerate projects to meet user-defined constraints and reduce the inconvenience to the traveling public. Although there is information about acceleration projects in other industries, there has been little specifically aimed at highway projects. A domestic scan sponsored by the National Cooperative Highway Research Program was tasked with providing information in this area. The objective of this paper is to synthesize the resulting information into fundamentals that support successful planned accelerated highway project delivery. Case studies of how departments of transportation successfully accelerated the construction of four very different projects in California, Florida, and Texas serve as the basis for identifying these fundamentals. The fundamentals include upfront and detailed planning, designs that facilitate accelerated construction, a collaborative environment for project stakeholders, and incentives and disincentives to motivate construction contractors. [ABSTRACT FROM AUTHOR]

As part of Florida DOT (FDOT)'s Partnering Program, a temporary roadway was designed and constructed using three different pavement sections. The program consisted of pavement construction monitoring and field/laboratory testing during construction, prior to opening to traffic and demolition. The study documents the findings of the ongoing efforts by FDOT to assess the applicability of untreated recycled asphalt pavement (UNRAP) as base course for pavement sections. Three different temporary pavement sections were constructed. Two sections were constructed with UNRAP, one with a stabilized subgrade and the other with a compacted subgrade. The third section was constructed with a limerock base and stabilized subgrade, and was used for comparison purposes. The UNRAP material used in the temporary pavement sections was milled off of the existing roadway. Laboratory and field testing, including Dynaflect and falling weight deflectometer (FWD), were performed and evaluated. The study suggested the UNRAP base performed as well or better than the limerock base. The results of this study, together with a previous study, indicate that UNRAP can be used successfully as base material for both traffic lanes and shoulders. Use of UNRAP for base courses on certain projects is a cost-effective alternate over conventional base materials. The results of the Dynaflect and FWD and the rut depths observed throughout the limited duration of this project were comparable to those of the limerock base. The results also indicate a substantial improvement of UNRAP properties with time. This paper presents the results of the field and laboratory testing, as well as engineering analyses and evaluations. Recommendations for future construction and research will be discussed. The data gathered so far suggest that UNRAP is a viable alternate material for base courses, but are we ready for it? [ABSTRACT FROM AUTHOR]

Hurricane Charley was the first Category 4 hurricane to strike Florida after 1992. This paper presents results of a study to investigate the performance of 425 of 747 roofs of new homes in Punta Gorda Isles, a subdivision of Punta Gorda that was directly in the path of Hurricane Charley shortly after it made landfall. The homes examined were larger, concrete/clay tiled roof homes having irregular floor plans and complex roof configurations not explicitly addressed by prevailing wind load codes. Roof damage was evaluated using images from aerial photographs taken at an elevation of approximately 762 m (2,500 ft.) Specialized software was used to quantify damage. Damage was classified based on tile loss area. The study showed that the vast majority of the roofs were either undamaged or sustained minor damage. Fewer than 14% were classified as damaged. The most common observed tile loss was along ridges, corners, or in the hip zone where negative uplift pressures are recognized to be the highest. Given the modest observed damage, prevailing methods for estimating wind loads for irregular buildings specified in codes may be adequate. Problems encountered may be best resolved through new details for attaching tiles on ridges, corners, and hip zone. [ABSTRACT FROM AUTHOR]

The paper presents an experimental study of the actual dynamic effects for a preselected typical highway bridge. Knowledge of the dynamic impact factors is important for accurate determination of the ultimate load capacity and performance assessment of constructed bridges. Static and dynamic field tests were performed on a two-lane concrete highway bridge built in 1999 on U.S. 90 in northwest Florida. During the tests, one or two fully loaded trucks crossed over the bridge, which was instrumented with strain gauges, accelerometers, and displacement transducers. A wooden plank was placed across the lanes for some runs to trigger extensive dynamic vibration and to simulate poor road surface conditions. Data collected from the tests were used for comprehensive assessment of the bridge under dynamic loading. Impact factors obtained from the tests with higher speeds were found larger than corresponding values recommended by bridge codes. Analysis revealed that stiff vehicle suspension, road surface imperfection, and “bouncing” of the truck loading contributed to the high impact factors. Experimental data were also used for validation of the finite-element models developed for the vehicle–bridge system. [ABSTRACT FROM AUTHOR]

As a result of recent changes in the requirements involving hurricane extreme events (e.g., wind velocities), the Florida Department of Transportation has moved away from cable-stayed signs, signals, and lights systems to mast arm/pole structures. Unfortunately, the newer systems develop significant lateral and torque loading on their foundations (e.g., drilled shafts). Current design practice for a mast arm/pole foundation is to treat lateral loading and torsion separately (i.e., uncoupled); however, recent field-testing suggests otherwise. This paper reports on the results of 91 centrifuge tests. 54 of the tests were conducted in dry sand and 37, in saturated sands. The tests varied the lateral load to torque ratios, shaft embedment depths, and soil strengths. The experiments revealed that even though the torsional resistances of the shafts were not influenced by lateral load, the shafts’ lateral resistance was significantly impacted by torsion. Reductions in lateral resistance of 50% were recorded for shafts under high torque to lateral load ratios. Using the free earth support assumption and the ultimate soil pressure the soil pressure distribution along the shaft was developed. Using force and moment equilibrium, as well as the applied torque, maximum shear, and moments were computed. The predicted values were found to be within 25% (10% on average, except for the tests in saturated dense sand with polymer slurry) of the experimental results. [ABSTRACT FROM AUTHOR]

Expansion of the Florida Turnpike in Polk County involved construction over reclaimed phosphatic clay deposits. This paper presents the laboratory tests, numerical analyses, and field monitoring of the consolidation process. The laboratory tests involved oedometer tests prior and during surcharging, and constant rate of strain tests to evaluate permeability versus void ratio. The numerical work considered two-dimensional small versus large deformation theory using a coupled mixture approach. Both theories employed a modified cam-clay with a hyperelastic constitutive model; the field study monitored settlements and pore pressure from settlement plates, settlement cells, and piezometers. It was discovered that both small and large deformation theory did a good job in predicting the laboratory consolidation process, however, the large deformation theory predicted the field response better, especially for the deeper deposits (i.e., over 6 m), which was attributed to its updating geometry influences on pore pressures and effective stresses from coupled mixture theory. [ABSTRACT FROM AUTHOR]

The objective of the research reported in this paper was to determine the potential water-savings effectiveness of Toro Intelli-Sense evapotranspiration (ET)-based irrigation controllers in single-family homes. Of the 36 cooperators selected, 21 cooperators were outfitted with Toro Intelli-Sense TIS-612 (the ET group) and the remaining 15 were used as comparisons. The ET group reduced irrigation compared to the gross irrigation requirement by 23-41% and the 9-year historical average by 23-34%. Results varied based on the relationship between historical irrigation and the gross irrigation requirement, with water savings of 24%, no difference, and an increase of 54% when the historical value exceeded, approximated, and was less than the gross irrigation requirement, respectively. Turfgrass quality was maintained above an acceptable threshold for both treatments. In southwest Florida, a properly programmed Intelli-Sense controller is recommended when irrigation exceeds the gross irrigation requirement and at least 696 mm of irrigation is applied annually. Other smart-irrigation technologies would be more appropriate in locations for which the irrigation rate is less than the gross irrigation requirement. [ABSTRACT FROM AUTHOR]