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This article presents experimental data on the earth pressures that develop between mechanically stabilized earth (MSE) wall panels that are tied together in an unyielding condition. Prior to design and construction, an extensive literature review was conducted to ensure the MSE wall adhered to the local standard specifications for road and bridge construction, current design codes, and the construction sequencing specified by the wall panel manufacturer. The Strong Wall at the University of Florida's Structures and Materials Laboratory was utilized to construct a model full-scale MSE wall using inextensible reinforcement, with 140 locations continuously monitored. The MSE wall was divided into two different relative compaction zones, 95% and 103% of the reinforced soil's optimum dry density, to investigate a range of friction angles that can develop during conventional construction. To achieve the necessary aspect ratio of 0.3 specified by practitioners for use in real-world applications, a reaction frame was incrementally loaded on top of the reinforced backfill to simulate additional wall height and overburden stress. Earth pressure coefficients were found for each compacted soil lift and incremental load from the reaction frame for both states of soil density. A force equilibrium analysis was conducted to ensure all forces within the experimental setup were accounted for to validate the results. From the derived earth pressure coefficients, it was observed that earth pressures moved from a passive condition to an active or at-rest condition as the soil-height increased above each reinforcement level. It was concluded that increased lateral stress develops from the compaction effort in an unyielding condition, which is not accounted for using conventional MSE design methods. Consequently, an equation was developed that incorporates a variable friction angle (φ) based on the compaction effort for an unyielding condition that closely followed the trends of the measured results. [ABSTRACT FROM AUTHOR]

Florida limestone can be challenging to recover during coring operations, as the rock generally is soft, porous, and often highly weathered. Low recoveries coupled with poor rock quality are common in Florida, which limits the data available for geotechnical design. However, the low recoveries and poor rock quality may be attributable to coring techniques and not the rock's in situ condition. This paper explores integrating measuring while drilling (MWD) into standard coring procedures to provide in situ strength assessment and optimize core recoveries and rock quality to improve rock mass characterization. Six drilling parameters were monitored during the research, and a controlled drilling environment was developed to investigate each monitored parameter's effects. Variable drill bit configurations were also explored to investigate the effects of bit geometry. Interdependent relationships between the drilling parameters were discovered and a new concept of operating within optimal drilling parameter ranges based on these relationships is introduced. The coring practices developed in the controlled environment were then tested in natural Florida limestone. It was concluded that operating within the optimal ranges allows in situ strength assessment and improves core recoveries and rock quality. Key words: measuring while drilling, specific energy, core recovery, rock quality, Florida limestone. Il peut etre difficile de recuperer le calcaire de Floride au cours des operations de carottage, puisque la roche est generalement molle, poreuse et generalement tres alteree. Les faibles taux de recuperation et la mauvaise qualite de la roche sont des phenomenes frequents en Floride, limitant ainsi les donnees dont on dispose pour la conception geotechnique. Toutefois, les faibles taux de recuperation et la mauvaise qualite de la roche sont sans doute attribuables aux techniques de carottage et non a l'etat de la roche in situ. Le present document explore l'integration de la mesure en cours de forage (<< MWD >>) dans les procedures de carottage standard afin de proceder a une evaluation de la resistance in situ et d'optimiser les recuperations de carottes et la qualite de la roche en vue d'ameliorer la caracterisation de la masse rocheuse. Au cours de la recherche, six parametres de forage ont ete surveilles et un environnement de forage controle a ete mis au point pour analyser les effets de chaque parametre surveille. Des configurations variables de trepans ont egalement ete etudiees pour analyser les effets de la geometrie des trepans. On a decouvert des rapports d'interdependance entre les parametres de forage et on a introduit un nouveau concept de fonctionnement dans des plages de parametres de forage optimales introduites dans ces rapports. Par la suite, on a mis a l'essai les pratiques de carottage elaborees dans l'environnement controle dans du calcaire naturel de la Floride. La conclusion a ete etablie selon laquelle l'exploitation dans les plages optimales permet d'evaluer la resistance in situ et d'ameliorer la recuperation des carottes et la qualite de la roche. [Traduit par la Redaction] Mots-cles : mesure en cours de forage, energie specifique, recuperation de carotte, qualite de la roche, calcaire de Floride., Introduction Rock coring within the state of Florida often is challenging because of the soft-porous nature of the bedrock and the high degree of variability and weathering that is found [...]

The focus of this research is the real-time assessment of drilled shaft capacity based on the unconfined compressive strength ([q.sub.u]) obtained from measuring while drilling (MWD). Measures of [q.sub.u], a function of rock strength commonly used in drilled shaft design, are provided through five monitored drilling parameters: torque, crowd, rotational speed, penetration rate, and bit diameter. Monitored shaft installations took place at three separate locations on drilled shafts, which were subsequently load tested. Using the [q.sub.u] values obtained from MWD, side shear was estimated in portions of each shaft where instrumented segments indicated the side shear was fully mobilized for direct comparison. To consider all of the current side shear equations used in Florida drilled shaft design, the estimation of tensile strength ([q.sub.t]) in real time was also needed. This led to a theoretical approach to establish the [q.sub.t]/[q.sub.u] relationship that was later verified empirically and provided new correlations between material and mechanical properties of Florida geomaterials. A comparative analysis indicated that the results from multiple established side shear equations, used with [q.sub.u] from MWD, align well with the results obtained from load testing. This suggests that estimating drilled shaft capacity from MWD is viable to reduce spatial uncertainty. Key words: drilled shaft, rock auger, measuring while drilling, Florida limestone, specific energy. L'objectif de cette etude est l'evaluation en temps reel de la capacite du puits fore base sur la resistance en compression simple ([q.sub.u]) obtenue a partir de la mesure en cours de forage (MWD). Les mesures de [q.sub.u], une fonction de la resistance de la roche communement utilisee dans la conception des puits fores, sont fournies par cinq parametres de forage surveilles: couple, foule, vitesse de rotation, vitesse de penetration et diametre du trepan. Des installations a puits controle ont eu lieu a trois endroits differents sur des puits fores qui ont ensuite ete soumis a des essais de charge. En utilisant les valeurs de [q.sub.u] obtenues a partir de MWD, le cisaillement lateral a ete estime dans des parties de chaque puits ou des segments instrumentes ont indique que le cisaillement lateral etait entierement mobilise pour une comparaison directe. Afin de prendre en compte toutes les equations de cisaillement lateral utilisees dans la conception des puits fores en Floride, l'estimation de la resistance a la traction ([q.sub.t]) en temps reel etait egalement necessaire. Cela a conduit a une approche theorique pour etablir la relation [q.sub.t]/[q.sub.u] qui a ensuite ete verifiee empiriquement et a fourni de nouvelles correlations entre les proprietes materielles et mecaniques des geomateriaux de la Floride. Une analyse comparative a indique que les resultats de plusieurs equations de cisaillement lateral etablies, utilisees avec [q.sub.u] de MWD, s'harmonisent bien avec les resultats obtenus a partir des essais de charge. Ceci suggere que l'estimation de la capacite de puits fore par MWD est viable pour reduire l'incertitude spatiale. Mots-cles: puits fore, tariere a roche, mesure en cours de forage, calcaire de Floride, energie specifique., Introduction This paper explores using measurements of unconfined compressive strength, obtained from measuring while drilling shafts, to estimate side shear capacity in real time. The research discussed is part of [...]

The focus of this research is the real-time assessment of rock strength (unconfined compressive strength, [q.sub.u]) during drilled shaft installations in Florida limestone, where measures of rock strength are provided through five monitored drilling parameters: torque, crowd, rotational speed, penetration rate, and bit diameter. To complete the study, both a laboratory and field investigation were required. This paper covers drill rig instrumentation, measuring rock strength during field drilling, and the comparative analysis of rock strength with conventional methods. Real-time measurements were recorded for each drilling parameter and graphically displayed on an in-cab monitor and wirelessly transmitted to an external computer. Measures of rock strength were estimated using a laboratory-developed equation with the monitored drilling parameters for real-time field assessment. Measuring while drilling in the field took place at three separate locations where drilled shaft load testing occurred. Comparative analyses between the monitored shaft installations and core samples subjected to unconfined compression indicated the results aligned well when recoveries were good. As recoveries diminished, the mean strengths were comparable, but more variable. Key words: drilled shaft, measuring while drilling, construction monitoring, Florida, limestone. L'objectif de cette recherche est Revaluation en temps reel de la resistance de la roche (resistance a la compression non confinee, [q.sub.u]) pendant les installations de puits fores dans le calcaire de Floride; ou les mesures de la resistance de la roche sont fournies par cinq parametres de forage surveille : le couple, la pression verticale vers le bas, la vitesse de rotation, le taux de penetration et le diametre du trepan. Afin de completer la recherche, un essai en laboratoire et un essai sur le terrain ont ete necessaries. Ce document couvre l'instrumentation de l'appareil de forage, la mesure de la resistance de la roche pendant le forage sur le terrain et l'analyse comparative de la resistance de la roche avec les methodes conventionnelles. Des mesures en temps reel ont ete enregistrees pour chaque parametre de forage et affichees graphiquement sur un moniteur dans la cabine et transmises sans fil a un ordinateur externe. Les mesures de la resistance des roches ont ete estimees a l'aide d'une equation developpee en laboratoire avec les parametres de forage surveilles pour Revaluation en temps reel sur le terrain. La mesure en cours de forage sur le terrain a eu lieu a trois endroits differents ou des essais de charge des puits fores ont ete effectues. Des analyses comparatives entre les installations de puits controlees et les carottes de forage soumises a une compression non confinee ont indique que les resultats etaient bien alignes, lorsque les prelevements d'echantillons etaient bons. A mesure que les prelevements diminuaient, les forces moyennes etaient comparables, mais plus variables. [Traduit par la Redaction] Mots-cles: puits fores, mesure en cours de forage, surveillance de la construction, Floride, calcaire., Introduction Over the past few decades there has been an increase in the use of drilled shafts to support large structures in Florida. The shift from driven piles to drilled [...]

Our research evaluated current cone penetration test (CPT) pile design methodologies (Schmertmann, Laboratoire Central des Ponts et Chaussees (LCPC), etc.), modified one of these methods (Philipponnat method), and proposed a new one to improve future driven pile designs. This was accomplished by evaluating 14 pile-capacity-design methods based on CPT data. Furthermore, load and resistance factor design (LRFD) resistance factors for each method were calculated using 21 cases from Florida and 28 from Louisiana. The resulting resistance factors were not satisfactory for any of these methods. A new design method--the University of Florida (UF) method--was proposed taking into account cementation, soil type, and historical data. The LRFD resistance factor was also assessed for this new method. The proposed UF method provides better LRFD resistance factors for both Florida and Louisiana soils. It could be a promising alternative for improving pile design. Key words: cone penetration test, driven pile, ultimate axial capacity, sand, clay. Notre recherche evalue les methodologies actuelles de conception des pieux (Schmertmann, Laboratoire Central des Ponts et Chaussees (LCPC), etc.) basees sur les essais de penetration du cone (EPC), modifie l'une de ces methodes (methode Philipponnat), et propose une nouvelle methode pour ameliorer les conceptions futures de pieux enfonces. Ceci a ete realise par revaluation de quatorze methodes de conception de capacite de pieux basees sur des donnees d'EPC. De plus, les facteurs de resistance provenant du facteur de conception en charge et resistance (FCCR) pour chaque methode ont ete calcules a partir de 21 cas en Floride et de 28 cas en Louisiane. Les facteurs de resistance ainsi obtenus n'etaient pas satisfaisants pour aucune des methodes. Une nouvelle methode de conception, appelee <>, est proposee. Cette nouvelle methode tient compte de la cimentation, du type de sol et des donnees historiques. Le facteur de resistance FCCR a aussi ete evalue pour cette nouvelle methode. La methode UF proposee permet d'obtenir des meilleurs facteurs de resistance FCCR autant pour les sols de Floride que ceux de Louisiane. La methode pourrait etre une alternative prometteuse pour ameliorer la conception des pieux. Mots-cles : essai de penetration du cone, pieu fonce, capacite axiale ultime, sable, argile. [Traduit par la Redaction], Introduction From the 1960s to the 1980s, the Florida Department of Transportation (FDOT) sponsored research at the University of Florida to evaluate the methods used for calculating static pile capacity [...]

Load and resistance factor design (LRFD) is a method that aims at meeting specified target reliabilities (probabilities of failure) of engineered systems. The present work focuses on ultimate side friction resistance for axial loads on single cylindrical drilled shaft foundations in the presence of spatially variable rock/soil strength. Core sample data are assumed to provide reliable information about local strength in terms of mean, coefficient of variation and spatial correlation structure (variogram) at a site. The geostatistical principle of support up-scaling is applied to quantify the reduction in variability between local strength and the average ultimate shaft side friction resistance without having to recur to lengthy stochastic finite difference/element simulations. Site and shaft specific LRFD resistance factors ([PHI] values) are given based on the assumption of lognormal load and resistance distributions and existing formulas recommended by the Federal Highway Administration. Results are efficiently represented in dimensionless charts for a wide range of target reliabilities, shaft dimensions, and geostatistical parameters including nested variograms of different types with geometric and/or zonal anisotropies. Field data of local rock strength is used to demonstrate the method and to evaluate the sensitivity of obtained resistance factors to potentially uncertain variogram parameters. DOI: 10.1061/(ASCE)GT.1943-5606.0000327 CE Database subject headings: Load and resistance factor design; Failures; Reliability; Deep foundations; Drilled shafts. Author keywords: Load resistance factor design; Failure; Reliability; Deep foundation; Geostatistics; Variogram; Variance reduction.

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. DOI: 10.1061/(ASCE)1090-0241(2005)131:9(1118) CE Database subject headings: Laboratory tests: Numerical analysis; Soil deformation: Pore pressure; Florida; Highway construction.