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Title: Identifying Shallow Foundation Failure Modes and Mechanisms Using Surveillance of a Transparent Granular Soil Surrogate.
Creator: Purdy, Denys W., Sobhan, Khaled, Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description: A transparent soil model of granular fused quartz is developed to study the mechanics of shallow foundations. Soil models, unreinforced and reinforced, prepared at relative densities 0.34 (loose) and 0.64 to 0.69 (medium dense) are tested using a rectangular footing (25 mm wide x 40 mm long) under strain-controlled loading. Digital Image Correlation is used to identify displacements of a seeded central plane parallel to footing width (B) and construct vector fields and contour plots. Fiber...
Show moreA transparent soil model of granular fused quartz is developed to study the mechanics of shallow foundations. Soil models, unreinforced and reinforced, prepared at relative densities 0.34 (loose) and 0.64 to 0.69 (medium dense) are tested using a rectangular footing (25 mm wide x 40 mm long) under strain-controlled loading. Digital Image Correlation is used to identify displacements of a seeded central plane parallel to footing width (B) and construct vector fields and contour plots. Fiber-reinforced soil model data analysis is inconclusive. For the unreinforced medium-dense soil, minimum and peak magnitude horizontal displacements occurred directly under the footing at the footing edges; whereas in the loose soil, peak magnitude horizontal displacement occurred directly under the footing. Vector and contour plots revealed that a medium dense soil gradually distributes smaller magnitude displacements over a broad area, in contradistinction to acute, highly localized displacements of larger magnitude in a loose soil.
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Date Issued: 2017
PURL: http://purl.flvc.org/fau/fd/FA00004832, http://purl.flvc.org/fau/fd/FA00004832
Subject Headings: Soils--Testing., Soils.
Format: Document (PDF)

Title: Time- stress-compressibility characteristics of cementitiously stabilized organic soils.
Creator: Sarsour, Anhar, Sobhan, Khaled, Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description: Effect of cementitious stabilization on the stress-compressibility characteristics of three different South Florida organic soils were evaluated in this study. The objectives of the research were to (l) determine if the secondary compression characteristics of organic soils and peats can be stabilized with (a) cement only, (b) binary blends of cement/slag (C-S), cement/gypsum (C-G), and cement/cement-kiln-dust (C-CKD) and (c) ternary blend of cement-slag-gypsum in equal proportions; (ll)...
Show moreEffect of cementitious stabilization on the stress-compressibility characteristics of three different South Florida organic soils were evaluated in this study. The objectives of the research were to (l) determine if the secondary compression characteristics of organic soils and peats can be stabilized with (a) cement only, (b) binary blends of cement/slag (C-S), cement/gypsum (C-G), and cement/cement-kiln-dust (C-CKD) and (c) ternary blend of cement-slag-gypsum in equal proportions; (ll) quantify the effectiveness of cementitious stabilization by evaluating the time-stress-compressibility (t-log σ'v - e) relationship in terms of the Cα / Cc ratio; and (lll) provide some guidelines for selecting optimum dosage of cementitious materials in deep mixing methods when organic soils and peats are encountered. It was concluded that cementitious mixes containing various waste materials is effective in controlling the secondary compression behavior of organic soils, and therefore should be considered in deep mixing methods as a sustainable practice.
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Date Issued: 2014
PURL: http://purl.flvc.org/fau/fd/FA00004326, http://purl.flvc.org/fau/fd/FA00004326
Subject Headings: Environmental geotechnology, Pavements, Soil cement, Soil consolidation, Soil mechanics, Soil penetration test, Soil stabilization
Format: Document (PDF)

Title: Influence of Median Grain Size Ratio on the Strength and Liquefaction Potential of Loose Granular Fills.
Creator: Waganaar, Spencer, Sobhan, Khaled, Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description: The characterization of silty soils is usually designated by the percentage of silt contained within the soil matrix, along with the soil’s void ratio, which is used to describe the soil’s current state. The use of these parameters to assess a soil’s strength and undrained behavior is limited when finer material is contained within the soil. Therefore, additional parameters must be considered in order to correctly assess the strength and liquefaction potential of silty soils. These additional...
Show moreThe characterization of silty soils is usually designated by the percentage of silt contained within the soil matrix, along with the soil’s void ratio, which is used to describe the soil’s current state. The use of these parameters to assess a soil’s strength and undrained behavior is limited when finer material is contained within the soil. Therefore, additional parameters must be considered in order to correctly assess the strength and liquefaction potential of silty soils. These additional parameters include the skeleton void ratio, equivalent void ratio and granulometric factors. The current research investigates the influence of granulometric parameters, specifically the Median Grain Size Ratio (D50/d50), denoted as μDR (or MDR within graphs and charts), on the strength and liquefaction potential of loose silty sands. A series of undrained monotonic triaxial compression tests (σ3’= 69, 83, and 103 kPa) are performed on reconstituted soil samples, using three different base sand samples and a constant silt material. As a result, three distinct median grain size ratios (μDR = 4.2, 6.75, and 9) were tested with fines content ranging from 0-30% for each μDR. The undrained shear strength at all confining pressures tends to increase with in μDR; beyond 10% fines content there was no noticeable influence of μDR. At any μDR the excess PWP is higher than that of clean sand, when fines content is larger than 5% fines content. The slope of the instability line and phase transformation line are directly affected by the μDR and fines content, with an increase in the instability line and decrease in the phase transformation line with a growing μDR. The results indicate loose granular fills can be designed to be stronger and more resilient under extreme conditions by careful choice of materials in which the μDR>6.75 and the fines content does not exceed 10%.
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Date Issued: 2016
PURL: http://purl.flvc.org/fau/fd/FA00004639, http://purl.flvc.org/fau/fd/FA00004639
Subject Headings: Slopes (Soil mechanics), Soils., Soil liquefaction., Geotechnical engineering.
Format: Document (PDF)

Title: Use of piezocone penetration tests for rapid in-situ characterization of Florida organic soil.
Creator: Huynh, Hieu H., Florida Atlantic University, Sobhan, Khaled
Abstract/Description: Organic soils generally are characterized by low strength and high compressibility. Visual observations of State Road 15/US 98 in western Palm Beach County, Florida indicate numerous cracking and significant rutting and raveling along the roadway caused by the consolidation and long-term secondary compression of the organic soils due to soil and pavement dead load. Since sampling of undisturbed soft organic soils is difficult, and subsequent laboratory tests are expensive and time-consuming,...
Show moreOrganic soils generally are characterized by low strength and high compressibility. Visual observations of State Road 15/US 98 in western Palm Beach County, Florida indicate numerous cracking and significant rutting and raveling along the roadway caused by the consolidation and long-term secondary compression of the organic soils due to soil and pavement dead load. Since sampling of undisturbed soft organic soils is difficult, and subsequent laboratory tests are expensive and time-consuming, there is a need for rapid in-situ characterization of these unstable foundation soils. This study evaluates the capabilities of Piezocone Penetration tests (CPTu), coupled with pore pressure dissipation tests, for estimating the strength, modulus, compressibility, and time rate of consolidation characteristics of organic soils and peat in Florida. The compression index (Cc) and coefficient of consolidation (cv), predicted from CPTu, showed reasonable correlation with laboratory-derived properties.
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Date Issued: 2006
PURL: http://purl.flvc.org/fcla/dt/13379
Subject Headings: Soil stabilization--Florida, Soil consolidation--Florida, Soil mechanics--Florida, Soil penetration test
Format: Document (PDF)

Title: Ecological impact of arsenic, chromium and lead from application of recovered screened material on Florida soils.
Creator: Scarlatos, Dimitrios., Florida Atlantic University, Scarlatos, Panagiotis (Pete) D., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Disposal of construction and demolition (C&D) debris is a major problem. During recycling operations, the debris is passed over screens, generating what is called Recovered Screened Material (RSM). Previous analyses of RSM indicated high arsenic (As) levels. Thus, RSM is disposed in landfills in spite of the fact that natural soils may contain As levels higher than the proposed concentrations for soil clean-up goals. RSM samples were collected and analyzed from seven C&D debris recycling...
Show moreDisposal of construction and demolition (C&D) debris is a major problem. During recycling operations, the debris is passed over screens, generating what is called Recovered Screened Material (RSM). Previous analyses of RSM indicated high arsenic (As) levels. Thus, RSM is disposed in landfills in spite of the fact that natural soils may contain As levels higher than the proposed concentrations for soil clean-up goals. RSM samples were collected and analyzed from seven C&D debris recycling facilities and from other sites. The average arsenic content found in RSM ranged between residential and industrial clean-up goals. Chromium and lead levels in RSM were very low. The RSM quality depends mainly on the waste stream. Recycling procedures do not have any major effect on the RSM. Arsenic levels in natural soils showed a wide variability. Almost half of the soil samples had an arsenic level comparable to that found in RSM.
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Date Issued: 1998
PURL: http://purl.flvc.org/fcla/dt/15532
Subject Headings: Soil pollution--Florida, Soils--Florida--Environmental aspects
Format: Document (PDF)

Title: Long-term pullout resistance of geogrid reinforcement for retaining walls.
Creator: Gao, Shangsui., Florida Atlantic University, Reddy, Dronnadula V.
Abstract/Description: An experimental and analytical investigation is presented for two types of geogrids: HDPE (High Density Polyethylene) and PET (Polyester). Sand and limerock were used for the backfill material, which meet the FDOT (Florida Department of Transportation) Material Specifications, with simulation of unsaturated and saturated condition. Eight pullout test boxes were designed and constructed, each with a specially designed stainless steel clamp. The measured strain-time relations for unsaturated...
Show moreAn experimental and analytical investigation is presented for two types of geogrids: HDPE (High Density Polyethylene) and PET (Polyester). Sand and limerock were used for the backfill material, which meet the FDOT (Florida Department of Transportation) Material Specifications, with simulation of unsaturated and saturated condition. Eight pullout test boxes were designed and constructed, each with a specially designed stainless steel clamp. The measured strain-time relations for unsaturated and saturated soils for various levels of the pullout force until the peak value (up to 10,000 hours of exposure), and varying distances from the loading end were plotted. The normal and principal stresses in the soil, and the strains along the geogrid were determined from the finite element analysis for the unsaturated soil condition for various pullout force levels. The results were analyzed and a generalized method proposed for practical design using sliding resistance factors.
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Date Issued: 1999
PURL: http://purl.flvc.org/fcla/dt/15689
Subject Headings: Retaining walls, Geogrids, Soil stabilization
Format: Document (PDF)

Title: Measuring temporal variability in biogenic gas content in peat soils using moisture probes.
Creator: Heij, Gerhard, Comas, Xavier
Date Issued: 2012-04-06
PURL: http://purl.flvc.org/fcla/dt/3348827
Subject Headings: Peatlands, Carbon cycle, Soil science, Environmental conditions, Geosciences, Soil moisture, Soils --analysis, Biogenic gas
Format: Document (PDF)

Title: Primary and secondary compression behavior of Florida organic soils.
Creator: Riedy, Kristopher W., Florida Atlantic University, Sobhan, Khaled, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description: A comprehensive laboratory investigation was conducted to evaluate the primary and secondary compression behavior of undisturbed organic silts and peats obtained from 11 locations along SR 15/US 98 in Palm Beach County, Florida. A total of 43 consolidation tests were performed. The primary objectives were as follows: (i) to conduct a series of standard consolidation tests to determine the Compression Index, Cc, and the Coefficient of Consolidation, cnu; (ii) to determine the Secondary...
Show moreA comprehensive laboratory investigation was conducted to evaluate the primary and secondary compression behavior of undisturbed organic silts and peats obtained from 11 locations along SR 15/US 98 in Palm Beach County, Florida. A total of 43 consolidation tests were performed. The primary objectives were as follows: (i) to conduct a series of standard consolidation tests to determine the Compression Index, Cc, and the Coefficient of Consolidation, cnu; (ii) to determine the Secondary Compression Index, Calpha, at stress levels (sigmanu'/sigmap') ranging from 0.30 to 1.15; and (iii) to employ the well-known Time-Stress-Compressibility concept to establish a unique relationship between C alpha and Cc. It was found that for all practical purposes, the Calpha/C c ratio at any stress level is 0.03, which is consistent with the values reported in the literature for similar soils. A constant Calpha/Cc ratio provides an approximation of Calpha once C c is determined from a standard consolidation test, and without the need of ongoing laboratory testing to predict long-term settlement.
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Date Issued: 2006
PURL: http://purl.flvc.org/fcla/dt/13386
Subject Headings: Soil consolidation--Measurement--Florida, Soil mechanics--Florida--Palm Beach County, Soils--Testing
Format: Document (PDF)

Title: Permanent strain accumulation in a granular material due to cyclic loading.
Creator: Genduso, Michael J., Florida Atlantic University, Sobhan, Khaled Dr.
Abstract/Description: To better characterize the accumulation of permanent deformation in a granular material, 40 Consolidated Drained (CD) triaxial tests (14 static and 26 cyclic) were performed under various stress conditions. A Digital Image Correlation (DIC) technique was utilized in some Repeated Load Triaxial (RLT) tests to measure global and localized strains visually in a non-contact manner. Additionally, the experimentally determined resilient material properties were used in a finite element based...
Show moreTo better characterize the accumulation of permanent deformation in a granular material, 40 Consolidated Drained (CD) triaxial tests (14 static and 26 cyclic) were performed under various stress conditions. A Digital Image Correlation (DIC) technique was utilized in some Repeated Load Triaxial (RLT) tests to measure global and localized strains visually in a non-contact manner. Additionally, the experimentally determined resilient material properties were used in a finite element based pavement modeling software called MICH-PAVE. Under cyclic loading, the permanent strain accumulation was found to obey the relationship of the form epsilonp =aNb, and the Resilient Modulus was used to develop the nonlinear K-theta model for granular materials. The observed/measured permanent strains using DIC/LVDT techniques compared favorably with the values obtained by the finite element simulation, and the evaluation of granular material by multiple methods seems promising for improved pavement design.
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Date Issued: 2005
PURL: http://purl.flvc.org/fcla/dt/13264
Subject Headings: Soils--Testing, Soil mechanics, Soil-structure interaction, Engineering geology, Rocks--Testing, Materials--Dynamic testing
Format: Document (PDF)

Title: The effects of systemic herbicide used for invasive species management on a native Florida scrub seed bank.
Creator: Ryan, Kathleen S., Florida Atlantic University, Violin, John
Abstract/Description: This study focused on whether use of ArsenalRTM to control an invasive, non-indigenous tree, Schinus terebinthifolius, would either negatively affect the seed bank in treatment areas of the study site or seeds in litter, 0-5 cm or 5-15 cm layers of the bank. Neither examining the whole site nor the two habitats produced conclusive results, but examining the three layers did. The litter layer appeared to be most sensitive to herbicide treatment with a 47% (p=0.03) reduction in seedling...
Show moreThis study focused on whether use of ArsenalRTM to control an invasive, non-indigenous tree, Schinus terebinthifolius, would either negatively affect the seed bank in treatment areas of the study site or seeds in litter, 0-5 cm or 5-15 cm layers of the bank. Neither examining the whole site nor the two habitats produced conclusive results, but examining the three layers did. The litter layer appeared to be most sensitive to herbicide treatment with a 47% (p=0.03) reduction in seedling emergence after treatment. Analysis of herbicide effect therefore required studying depth, habitat and study site. The litter layer, seldom considered in seed bank studies, produced 33% of emerging seedlings in this study. It is an extremely important component as it is the first place seeds are deposited before they percolate down into the soil. Damage to this layer will not only affect current seedling emergence, but future content of the seed bank below the surface.
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Date Issued: 2005
PURL: http://purl.flvc.org/fcla/dt/13301
Subject Headings: Soil seed banks--Florida, Soil absorption and adsorption--Florida, Soil remediation--Florida, Ecosystem management--Florida
Format: Document (PDF)

Title: Variations of soil physical properties across different habitats using GPR.
Creator: Leung, Tania, Graduate College
Date Issued: 2013-04-12
PURL: http://purl.flvc.org/fcla/dt/3361323
Subject Headings: Soil physics, Ground penetrating radar, Habitat (Ecology)
Format: Document (PDF)

Title: EFFECTS OF SALTWATER INTRUSION ON THE COMPRESSIBILITY BEHAVIOR OF THE EVERGLADES SOILS.
Creator: Ribeiro, Camila, Sobhan, Khaled, Florida Atlantic University, Department of Civil, Environmental and Geomatics Engineering, College of Engineering and Computer Science
Abstract/Description: The Florida Everglades is considered as a vulnerable wetland composed primary of organic rich peat soils, experiencing saltwater intrusion. Impact of increasing salinity on the strength and deformation properties of peat is unknown. A laboratory study was undertaken to evaluate how the growing salinity level due to sea level rise may alter the compressibility behavior of the Everglades soils. Sixteen 1-dimensional oedometer tests were conducted on undisturbed Everglades peat soils in two...
Show moreThe Florida Everglades is considered as a vulnerable wetland composed primary of organic rich peat soils, experiencing saltwater intrusion. Impact of increasing salinity on the strength and deformation properties of peat is unknown. A laboratory study was undertaken to evaluate how the growing salinity level due to sea level rise may alter the compressibility behavior of the Everglades soils. Sixteen 1-dimensional oedometer tests were conducted on undisturbed Everglades peat soils in two phases. Phase I included samples from Site 1 (saltwater) and Site 3 (freshwater) without any salinity addition. Phase II consisted of soil from Site 3 (freshwater) saturated in six different levels of salinity artificially added to the samples. Compressibility properties investigated in this study include compression index (Cc), coefficient of consolidation (Cv), hydraulic conductivity (K), and the Ca/Cc ratio. In general, it was observed that the increase in salinity beyond a threshold value tends to increase the soil compressibility properties, indicating a possible reduction in soil stability with saltwater intrusion.
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Date Issued: 2021
PURL: http://purl.flvc.org/fau/fd/FA00013783
Subject Headings: Everglades (Fla.), Peat soils, Saltwater encroachment, Compressibility
Format: Document (PDF)

Title: Coupled Effect of Geosynthetics and Randomly Distributed Fibers on the Stability of Reinforced Slopes.
Creator: Martins, Caique, Sobhan, Khaled, Florida Atlantic University, College of Engineering and Computer Science, Graduate College
Abstract/Description: The coupled effect of using geosynthetic reinforcement and randomly distributed fibers on the stability of slopes was evaluated using finite element modeling and limit equilibrium methods by analyzing a case study in Oslo, Norway. The main objective was to simulate the failure condition of the original slope and quantify the improved stability of a hypothetical reinforced slope constructed with geosynthetic layers and distributed discrete fibers. The stability of the slope was evaluated in...
Show moreThe coupled effect of using geosynthetic reinforcement and randomly distributed fibers on the stability of slopes was evaluated using finite element modeling and limit equilibrium methods by analyzing a case study in Oslo, Norway. The main objective was to simulate the failure condition of the original slope and quantify the improved stability of a hypothetical reinforced slope constructed with geosynthetic layers and distributed discrete fibers. The stability of the slope was evaluated in both the short-term condition with its' undrained shear strength parameters, and the long-term drained condition. Results indicate that the combination of the techniques was found to have a possible increase of about 40% in the short-term condition and about 60% in the long-term condition of the factor safety associated with the slope.
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Date Issued: 2019
PURL: http://purl.flvc.org/fau/fd/FA00013236
Subject Headings: Geosynthetics, Slope stability, Shear strength of soils
Format: Document (PDF)

Title: INVESTIGATING THE EFFECTS OF SEA-LEVEL RISE AND INCREASED SALINITY ON PEAT SOILS OF THE EVERGLADES (FLORIDA): IMPLICATIONS FOR CHANGES IN BIOGENIC GAS DYNAMICS AND PEAT COLLAPSE.
Creator: Sirianni, Matthew J., Comas, Xavier, Florida Atlantic University, Department of Geosciences, Charles E. Schmidt College of Science
Abstract/Description: While repeated transgressive and regressive sea level cycles have shaped south Florida throughout geological history, modern rates of sea level rise pose a significant risk to the structure and function of the freshwater wetland ecosystems throughout the low-lying Everglades region. Current regionally corrected sea level projections for south Florida indicate a rise of 0.42m by 2050 and 1.15m by 2100, suggesting the salinization of previously freshwater areas of the Everglades is conceivable....
Show moreWhile repeated transgressive and regressive sea level cycles have shaped south Florida throughout geological history, modern rates of sea level rise pose a significant risk to the structure and function of the freshwater wetland ecosystems throughout the low-lying Everglades region. Current regionally corrected sea level projections for south Florida indicate a rise of 0.42m by 2050 and 1.15m by 2100, suggesting the salinization of previously freshwater areas of the Everglades is conceivable. As freshwater areas become increasingly exposed to saltwater they experience shifts in vegetation composition, soil microbial populations, plant productivity, and physical soil properties that ultimately result in a phenomenon called peat collapse. Recent work in the Everglades has sought to further explain the mechanisms of peat collapse, however the physical changes to the peat matrix induced by saltwater intrusion are still uncertain. Moreover, the combination of physical alterations to the peat matrix associated with peat collapse and shifts in wetland salinity regimes will also likely disrupt the current carbon gas dynamics of the Everglades.
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Date Issued: 2020
PURL: http://purl.flvc.org/fau/fd/FA00013589
Subject Headings: Sea level rise, Peat soils, Everglades (Fla)
Format: Document (PDF)

Title: THE IMPACT OF NUTRIENT LOADING ON THE SOIL AND ROOT RESPIRATION RATES OF FLORIDA MANGROVES.
Creator: Faron, Natalie Therese, Benscoter, Brian, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
Abstract/Description: Coastal nutrient loading is a growing concern in urbanized communities and has led to alterations in above- and belowground processes throughout estuarine systems. Mangrove forests are highly productive coastal habitats that exhibit large carbon stocks contained mostly to the deep soils. Since nutrient enrichment has been found to increase mangrove aboveground growth, it’s presumed that nutrient enrichment will also increase belowground respiration rates. Disturbances in soil nutrient content...
Show moreCoastal nutrient loading is a growing concern in urbanized communities and has led to alterations in above- and belowground processes throughout estuarine systems. Mangrove forests are highly productive coastal habitats that exhibit large carbon stocks contained mostly to the deep soils. Since nutrient enrichment has been found to increase mangrove aboveground growth, it’s presumed that nutrient enrichment will also increase belowground respiration rates. Disturbances in soil nutrient content may alter the mangrove carbon cycle by increasing the amount of CO2 lost to the atmosphere from enhanced microbial and root respiration. In this study, soil respiration responded greatest to nitrogen enrichment, but pneumatophore root respiration responded greatest to phosphorus enrichment. Nutrient limitation can shift between different ecological processes and responses to nutrient enrichment tend to be system specific in tidally influenced ecosystems. Understanding the implications of coastal nutrient loading will improve ecosystem models of carbon exchange and belowground processes.
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Date Issued: 2021
PURL: http://purl.flvc.org/fau/fd/FA00013767
Subject Headings: Mangrove forests, Soil respiration, Carbon cycle (Biogeochemistry)
Format: Document (PDF)

Title: ANALYSIS OF PILE FOUNDATION SYSTEMS IN MULTI-LAYERED SOIL STRATA.
Creator: Arvan, Prakash Ankitha, Arockiasamy, Madasamy, Florida Atlantic University, Department of Civil, Environmental and Geomatics Engineering, College of Engineering and Computer Science
Abstract/Description: Pile foundations are subjected to vertical loads and significantly higher lateral loads due to wind, seismic effects, ocean waves and currents, and floating ice sheets. Applied vertical load on a pile is resisted by the skin friction and base resistance. The base resistance is provided by the soil layer and skin friction develops at the soil-pile interface. The lateral load on the pile is resisted by the soil-pile interaction effect, which is dependent on the pile and soil parameters....
Show morePile foundations are subjected to vertical loads and significantly higher lateral loads due to wind, seismic effects, ocean waves and currents, and floating ice sheets. Applied vertical load on a pile is resisted by the skin friction and base resistance. The base resistance is provided by the soil layer and skin friction develops at the soil-pile interface. The lateral load on the pile is resisted by the soil-pile interaction effect, which is dependent on the pile and soil parameters. Published literature shows that a properly designed Pile-to-Pile Cap (PTPC) connection will offer significant lateral resistance to the applied loads. The soil-pile system behavior is highly non-linear which requires a detailed study on the soil-structure interaction considering multi-layered soil strata and their properties. This Dissertation is divided into two parts: Evaluation of (A) the behavior and performance of PTPC connections, and (B) the load-displacement responses of a pile embedded in a multi-layered non-linear elastic soil strata subjected to static loads. A comprehensive literature review has been performed to study the factors affecting the PTPC connection performances and the load-displacement behavior of piles subjected to static lateral and axial loads considering soil-pile interactions. The objective of the study in Part A is to develop a PTPC connection design capable of producing adequate moment capacity of the pile by relying only on plain pile embedments without any special connection reinforcement details. The present study evaluates the local and global behavior of the PTPC connections with plain pile embedment through Finite Element Analyses (FEA).
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Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014124
Subject Headings: Pile foundations, Piling (Civil engineering), Soils
Format: Document (PDF)

Title: Studies of specific gene expression of phosphate transporters in sawgrass (Cladium jamaicense crantz) and cattail (Typha domingensis pers.).
Creator: Lin, Li, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description: In the Florida Everglades, sawgrass has been displaced by cattail, predominantly resulting from phosphate enrichment. It has been found that phosphate transporters and arbuscular mycorrhizal (AM) fungi play an important role in phosphate uptake in the plants. This study aimed to reveal the symbiosis between AM fungi and sawgrass and cattail and identify the phosphate transporters, especially AM-specific phosphate transporters in these two species. AM colonization was only found in sawgrass...
Show moreIn the Florida Everglades, sawgrass has been displaced by cattail, predominantly resulting from phosphate enrichment. It has been found that phosphate transporters and arbuscular mycorrhizal (AM) fungi play an important role in phosphate uptake in the plants. This study aimed to reveal the symbiosis between AM fungi and sawgrass and cattail and identify the phosphate transporters, especially AM-specific phosphate transporters in these two species. AM colonization was only found in sawgrass roots, not cattail, at low phosphate concentrations in lab and field samples by trypan blue staining. AM fungi could increase sawgrass growth and had little effect on cattail growth. Four phosphate transporters were identified in sawgrass. CjPT1, CjPT2 and CjPT3 were expressed in roots and shoots independent of AM fungi and phosphate availability, while CjPT4 appeared to be an AM regulated phosphate transporter gene and its expression was induced by AM fungi.
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Date Issued: 2010
PURL: http://purl.flvc.org/FAU/1930493
Subject Headings: Phosphorus, Physiological transport, Soil stabilization, Vegetation dynamics, Ecosystem management, Soil mineralogy, Plant physiology
Format: Document (PDF)

Title: Does residential landscape type affect nitrogen runoff and leaching?.
Creator: Erickson, John Erickson., Florida Atlantic University, Volin, John C.
Abstract/Description: Intensely maintained turfgrass landscapes have some potential for loss of fertilizer nitrogen (N) in both runoff and leaching. Lower maintenance vegetation used in mixed-species landscapes may reduce N leaching and runoff, which is important for reducing environmental pollution of surface and ground waters. However, few studies have examined this paradigm. Therefore, we constructed a field-scale facility to compare fertilizer N runoff and leaching between St. Augustinegrass (Stenotaphrum...
Show moreIntensely maintained turfgrass landscapes have some potential for loss of fertilizer nitrogen (N) in both runoff and leaching. Lower maintenance vegetation used in mixed-species landscapes may reduce N leaching and runoff, which is important for reducing environmental pollution of surface and ground waters. However, few studies have examined this paradigm. Therefore, we constructed a field-scale facility to compare fertilizer N runoff and leaching between St. Augustinegrass (Stenotaphrum secundatum (Walt.) Kuntze cv. 'Floratam') and a mixed-species landscape designed by the Florida Yards and Neighborhoods (FYN) program. A blended granular fertilizer was applied at a rate of 300 and 150 kg N ha-1 yr -1 on the turfgrass and mixed-species, respectively. During the 12-month study only one minor runoff event occurred (<0.2 cm) and N losses were insignificant. Annual N leaching losses were significantly greater on the mixed-species landscape, resulting in 4.80 g N m-2 compared to 0.41 g N m-2 for the St. Augustinegrass.
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Date Issued: 2000
PURL: http://purl.flvc.org/fcla/dt/15761
Subject Headings: Nitrogen fertilizers, Grasses--Fertilizers--Florida, Soils--Nitrogen content, Soils--Leaching
Format: Document (PDF)

Title: Cement stabilization of organic soils for controlling secondary compression behavior.
Creator: Ramirez, Juan., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description: Western Palm Beach County, FL is characterized by thick deposits organic soils at shallow depths. Because of their high void ratio and compressibility, these soils undergo large primary consolidation followed by extended periods of secondary compression causing excessive premature structural distress. Although soil stabilization has been largely used with remarkable results in soft, expansive and non-organic soils, limited research and practice exist in the implementation with highly organic...
Show moreWestern Palm Beach County, FL is characterized by thick deposits organic soils at shallow depths. Because of their high void ratio and compressibility, these soils undergo large primary consolidation followed by extended periods of secondary compression causing excessive premature structural distress. Although soil stabilization has been largely used with remarkable results in soft, expansive and non-organic soils, limited research and practice exist in the implementation with highly organic soils. The main motivation of this research was to investigate the effects of cement stabilization on the compressibility behavior of organic rich soils, and develop mix design criteria for optimum cement contents necessary to induce the desired engineering behavior. This optimized mix design may provide guidelines for Deep Mixing Methods in organic soils.
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Date Issued: 2009
PURL: http://purl.flvc.org/FAU/367760
Subject Headings: Soil consolidation, Measurement, Soils, Organic compound content, Soil remediation, Technological innovations, Concrete construction, Structural stability, Design
Format: Document (PDF)

Title: Stability Analysis of Geosynthetic Reinforced MSW Landfill Slopes Considering Effects of Biodegradation and Extreme Wind Loading.
Creator: Pant, Sharmila, Sobhan, Khaled, Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description: A numerical investigation was conducted to evaluate the geotechnical safety and slope stability of Municipal Solid Waste (MSW) landfills, considering the effects of geosynthetic reinforcements, biodegradation of the waste, and associated changes in material properties, and extreme wind force simulating hurricane conditions. Three different landfill slopes, 1:1, 1:2, and 1:3 having the height of 122m and width of 2134m, were analyzed using Limit Equilibrium Method (SLOPE/W) and Finite Element...
Show moreA numerical investigation was conducted to evaluate the geotechnical safety and slope stability of Municipal Solid Waste (MSW) landfills, considering the effects of geosynthetic reinforcements, biodegradation of the waste, and associated changes in material properties, and extreme wind force simulating hurricane conditions. Three different landfill slopes, 1:1, 1:2, and 1:3 having the height of 122m and width of 2134m, were analyzed using Limit Equilibrium Method (SLOPE/W) and Finite Element Modeling (ANSYS). Techniques developed in this study were used to analyze a case history involving a geogrid reinforced mixed landfill expansion located in Austria. It was found that few years after construction of the landfill, there is a significant decrease in the FS due to biodegradation. Extreme wind loading was also found to cause a substantial loss in the FS. The geosynthetic reinforcement increased the slope stability and approximately compensated for the damaging effects of biodegradation and wind loading.
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Date Issued: 2016
PURL: http://purl.flvc.org/fau/fd/FA00004707, http://purl.flvc.org/fau/fd/FA00004707
Subject Headings: Engineering geology -- Mathematical models, Fills (Earthwork), Geogrids -- Performance, Geosynthetics, Reinforced soils, Retaining walls -- Performance, Sanitary landfills, Slopes (Soil mechanics) -- Stability, Soil stabilization, Structural analysis (Engineering)
Format: Document (PDF)

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