FLORIDA PANTHER AND BLACK BEAR: A ROAD AND URBAN AVOIDANCE/UTILIZATION ANALYSIS AND IMPACTS OF LAND USE AND CLIMATE CHANGE ON LARGE CARNIVORE HABITAT IN FLORIDA

Florida is expanding its urban borders into areas of the native habitat. Increased expansion is predicted through the next several decades. Several sections of the state are home to large carnivores, such as Florida panther and black bear, which are important to ecosystem function. Expansion of roads and urban centers will greatly reduce the quality and quantity of carnivore habitat. In this study, I used Euclidean distance analyses and very high frequency (VHF) telemetry points to produce distance categories in which carnivores either have a negative/neutral/positive association with roads and urban centers. The seven black bear populations followed four different trends: 1) Slight avoidance of roads and urban centers, 2) strong avoidance of roads and urban centers, 3) neutrality toward roads and urban centers, and 3) one population with a positive association of roads. Florida panther showed strong avoidance to roads and urban centers. Finally I modeled Florida panther and black bear habitat using Maximum Entropy Species Distribution software and placed future urban expansion and sea level incursions associated with climate change over the habitat to find high priority conservation areas

Evaluation and prediction of 17th Street Canal I-wall stability using numerical limit analyses

Numerical limit analyses have been used to evaluate the stability of the 17th Street Canal I-wall levee during Hurricane Katrina. The potential formation of a water-filled gap along the canal-side soil-wall interface at failure is included in both the lower and upper bound formulations. The analyses replicate published 2D cross-sections and soil properties developed in forensic investigations carried out by the Interagency Performance Evaluation Task Force (IPET), and by the Independent Levee Investigation Team (ILIT). The current results provide an independent basis for understanding and evaluating the proposed failure mechanisms, and demonstrate that a water-filled gap is a necessary condition for the critical I-wall failure mechanism. Further limit analyses calculations produce credible estimates of the surge elevation that caused failure of the 17th Street Canal I-wall as well as predictions of a consistent failure mechanism. The numerical limit analyses show clearly how differences in the stability of the I-wall are linked to different interpretations of the stratigraphy and undrained shear strengths by IPET and ILIT. The analyses also show that effects of a thin layer of weak organic clay as postulated by ILIT are not necessary to explain the I-wall failure.Singapore. National Research FoundationSingapore-MIT Alliance for Research and Technolog

Effect of spatial variability on the slope stability using Random Field Numerical Limit Analyses

This paper presents a probabilistic approach to evaluating the geotechnical stability problem by incorporating the stochastic spatial variability of soil property within the numerical limit analyses (NLAs). The undrained shear strength and unit weight of soil are treated as a random field which is characterized by a log-normal distribution and a spatial correlation length. The current calculations use a Cholesky Decomposition technique to incorporate these random properties in NLAs. The Random Field Numerical Limit Analyses are applied to evaluate the effects of spatial variability of soil property on the slope stability and failure mechanism of slope. Monte Carlo iterations are then used to interpret the slope reliability and the dimension for collapsed slope for selected ranges of the coefficient of variation in soil property and the ratio of correlation length to slope height. Finally, the variation in the dimension of collapsed slope is examined in terms of the variability of slope reliability.Japan Society for the Promotion of Science (KAKENHI Grant 25289149

Model Prediction of Static Liquefaction: Influence of the Initial State on Potential Instabilities

This paper examines the influence of the initial state of sands on the potential for undrained instability. The main goal is to illustrate how advanced constitutive modeling of sand behavior can be used to evaluate the susceptibility for static liquefaction. The methodology is based on the concept of latent instability, in which the potential for collapse is contingent on particular boundary conditions. A generalized effective stress soil model, MIT-S1, is used to support the analysis and is combined with a theoretical approach for identifying loss of control owing to undrained shear perturbations. The theory is evaluated using experimental evidence available for Toyoura sand to point out the key role of void ratio and consolidation history and to provide experimental validation for the theory. Model predictions are then used to disclose the subtle role of drained preloading paths in promoting liquefaction instabilities. The ability of the constitutive model to reproduce the interplay between undrained kinematic constraints and material failure is fundamental in predicting potential instabilities arising from changes in drainage conditions. The examples shed light on the mechanics of static liquefaction and set a framework for applying the principles of material stability to the triggering analysis of flow slides induced by undrained shear perturbations

Ground Movements due to Shallow Tunnels in Soft Ground. I: Analytical Solutions

This paper presents simplified closed-form analytical solutions that can be used to interpret and predict ground movements caused by shallow tunneling in soft ground conditions. These solutions offer a more comprehensive framework for understanding the distribution of ground movements than widely used empirical functions. Analytical solutions for the displacement field within the ground mass are obtained for two basic modes of deformation corresponding to uniform convergence and ovalization at the wall of a circular tunnel cavity, based on the assumption of linear, elastic soil behavior. Deformation fields based on the superposition of fundamental, singularity solutions are shown to differ only slightly from analyses that consider the physical dimensions of the tunnel cavity, except in the case of very shallow tunnels. This work demonstrates a simplified method to account for soil plasticity in the analyses and illustrate closed-form solutions for a three-dimensional (3D) tunnel heading. A companion paper describes applications of these analyses to interpret field measurements of ground response to tunneling.University of Puerto Rico (Mayagüez Campus)Colorado Mining AssociationJacobs AssociatesKiewit-Kenny-Zachry (Contractor

Constitutive modelling approach for evaluating the triggering of flow slides

The paper presents a methodology to evaluate flow slide susceptibility in potentially liquefiable sandy slopes. The proposed approach accounts for both contractive and dilative volumetric behaviour during shearing using the MIT-S1 constitutive model. As a result, it is possible to distinguish among different types of undrained response induced by a rapid shear perturbation. The first part of the paper describes the general methodology for infinite slopes, providing an index of stability for incipient static liquefaction in shallow deposits. The methodology accounts for the anisotropy due to the initial stress state and uses simple shear simulations to assess instability conditions as a function of slope angle, stress state, and density of the soil. The resulting stability charts define the margin of safety against static liquefaction and the depths likely to be affected by the propagation of an instability. The second part of the paper applies the methodology to the well-known series of flow failures in a berm at the Nerlerk site. The MIT-S1 model is calibrated using published data on Nerlerk sands and in situ cone penetration test (CPT) data. The analyses show that in situ slope angles α = 10°–13° are less than the critical slope angle needed for incipient instability. Liquefaction and flow failures were therefore promoted by small perturbations in shear stresses that could be generated by rapid deposition of hydraulic fill

Numerical Simulation of a Shallow Geothermal Heating/Cooling System

In recent years, sustainability concerns have played an increasingly important role in building design, leading to rapid adoption of shallow geothermal heating/cooling systems. Understanding the heat exchange with the ground and associated thermo-hydro-mechanical processes involved is critical to ensure safe, efficient long-term performance of these geothermal systems. The current study considers heating/cooling loads for a large office building in Chicago, based on recommendations for typical DOE Commercial Benchmark Buildings and solves the coupled thermo-hydro-mechanical response of different soil types using the Code_Bright program. The paper considers a closed-loop system comprising an array of 80 m deep vertical heat exchangers that operates on a seasonal cycle with zero net heat transfer to the ground and can supply a heating load up to 2440 kW. Using estimated thermal properties of the Chicago clays, the THM analyses show negligible drift in the temperature within the surrounding ground for long-term operation of the geothermal system. However, when thermo-elastoplastic properties are considered, the analyses show that thermal cycling induces long-term settlements of the building

Coupling a branching process to an infinite dimensional epidemic process

Branching process approximation to the initial stages of an epidemic process has been used since the 1950's as a technique for providing stochastic counterparts to deterministic epidemic threshold theorems. One way of describing the approximation is to construct both branching and epidemic processes on the same probability space, in such a way that their paths coincide for as long as possible. In this paper, it is shown, in the context of a Markovian model of parasitic infection, that coincidence can be achieved with asymptotically high probability until o(N^{2/3}) infections have occurred, where N denotes the total number of hosts.Comment: 16 page

Effect of anisotropy in ground movements caused by tunnelling

This paper presents closed-form analytical solutions for estimating far-field ground deformations caused by shallow tunnelling in a linear elastic soil mass with cross-anisotropic stiffness properties. The solutions describe two-dimensional ground deformations for uniform convergence (u [subscript ε]) and ovalisation (u [subscript δ]) modes of a circular tunnel cavity, based on the complex formulation of planar elasticity and superposition of fundamental singularity solutions. The analyses are used to interpret measurements of ground deformations caused by open-face shield construction of a Jubilee Line Extension (JLE) tunnel in London Clay at a well-instrumented site in St James's Park. Anisotropic stiffness parameters are estimated from hollow-cylinder tests on intact block samples of London Clay (from the Heathrow Airport Terminal 5 project), and the selection of the two input parameters is based on a least-squares optimisation using measurements of ground deformations. The results show consistent agreement with the measured distributions of surface and subsurface, vertical and horizontal displacement components, and anisotropic stiffness properties appear to have little effect on the pattern of ground movements. The results provide an interesting counterpoint to prior studies using finite-element analyses that have reported difficulties in predicting the distribution of ground movements for the instrumented section of the JLE tunnel.George and Marie Vergottis FellowshipGoldberg-Zoino Fellowshi

The historical reputation of Edward IV 1461-1725

This thesis comprises a chronological study of different historical accounts of Edward IV’s life and reign from his life until the early eighteenth century. It focusses primarily on the way that historical portrayals of the king changed and developed alongside political, cultural and technological factors, something which has never been done before in any great detail. It begins begin with an examination of the primary sources from Edward’s reign, including the propagandist accounts The Historie of the Arrivall of Edward IV and The Chronicle of the Rebellion in Lincolnshire, the Crowland Chronicle Continuations, Warkworth’s Chronicle, and the vernacular urban chronicles of London and Bristol. It will contextualise these by briefly examining the English chronicle tradition up to the fifteenth century, as well as the historical treatment of other late medieval kings, especially Henry V and Henry VI The core of the thesis concerns itself with historical accounts over the period from 1485 to the early seventeenth century, during which Edward IV’s historical reputation underwent its greatest period of development. One chapter concerns itself with humanist authors, particularly Polydore Vergil and Thomas More, and the contribution of the French memoirist Philippe de Commynes. The next examines the impact of commercial printing during the mid-Tudor period, focussing upon the work of Richard Grafton, John Stow and Raphael Holinshed. Tudor and early Stuart Ballads, poems and plays featuring Edward are studied in order to give some indication of the perception of Edward IV in popular culture, with particular attention played to Heywood’s First and Second Parts of King Edward IV and Shakespeare’s Henry VI Part 3 and Richard III. Finally, later Stuart and early eighteenth century histories showing the final consolidation of Edward IV’s historical reputation are studied, with particular reference to William Habington’s History of Edward IV and Rapin de Thoyras’s History of England