Conferences, Lectures, & Seminars
Events for April
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Astani Civil and Environmental Engineering Seminar
Mon, Apr 23, 2012 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Mani Golparvar-Fard , Assistant Professor of Civil Engineering, Director, Real-time and Automated Monitoring and Control (RAAMAC) lab, Virginia Tech
Talk Title: Automated Visual Sensing and Augmented Reality Visualization of Construction Performance Metrics
Abstract: The destructive impact of construction and operation of the built environment in forms of materials, energy consumption, and Green House Gas emissions are becoming increasingly evident. As a result, government agencies are proposing incentive-based regulations for companies to reduce carbon footprint associated with their projects. In this modus operandi, AEC professionals need to find ways by which they can set realistic goals for schedule, cost, and carbon footprint of their projects, systematically track and monitor operations to promptly identify, process, and communicate discrepancies between actual and expected performances. Maintaining focus on these goals in the minutiae of construction activities is still more of an art than a science today. Hence, many projects do not meet their potential performance. Building on advanced computer vision, graphics, and machine learning techniques, this talk addresses how the utilization of images and videos along with BIM can be streamlined to monitor actual performance of a project, highlight deviations from expected performance, and provide an opportunity to initiate proactive actions to avoid them or minimize their impacts. The underlying hypotheses, algorithmic developments, and validations on using 1) video streams for automated construction productivity and environmental impact assessments, along with 2) images and BIM for automated progress and quality assessments are discussed in detail. Experimental results on several challenging datasets are presented and perceived benefits of the proposed methods are discussed. This talk will end with the implications of current and future research aimed at development of visual sensing techniques for automated tracking of productivity, safety, quality, carbon footprint, and visualizing performance deviations in augmented reality environments.
Host: Astani CEE Department
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Cassie Cremeans
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Astani Civil and Environmental Engineering Seminar
Mon, Apr 30, 2012 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Shengli Chen, integrated PoroMechanics Institute, the University of Oklahoma
Talk Title: Poroelastoplastic analytical solution of a cylindrical cavity in saturated rock formation
Abstract: The cavity expansion/contraction theory has wide applications in the areas of in-situ testing such as pressuremeter and piezocone penetrations, underground excavations and tunnel constructions in soil and rock, and wellbore instability in the oil and gas industry. In this research, a class of exact analytical solutions have been developed for the tunnel excavation/wellbore drilling problems in elastoplastic rock masses subjected to non-isotropic initial stresses, using the cavity contraction method and under both drained and undrained conditions. To provide realistic predictions of the rock behaviour, especially for the shale formation, the critical state-based modified Cam Clay and bounding surface models were adopted in the analyses. The uniqueness and novelty of the proposed analytical approach lies in the fact that the cavity boundary value problem is formulated within the Lagrangian description according to which both the constitutive relations and the equilibrium equation are described in terms of individual material particle. It is therefore possible to capture the evolution of the stress components and pore pressure/void ratio for any material point throughout the tunnel excavation/wellbore drilling processes, from elastic phase to elastoplastic and even failure phases of the deformation.
Numerical simulations were also conducted with the use of ABAQUS software. A user defined material subroutine (UMAT) has been developed and implemented into ABAQUS for the bounding surface model (Dafalias & Herrmann, 1980). The predictions from the ABAQUS analyses are generally in excellent agreement with the analytical solutions developed for both modified Cam Clay and the bounding surface models. The results show clearly that the stress history (overconsolidation ratio) has significant influence on the stress and pore pressure distributions as well as the development and progress of the plastic/elastic zones around the cavity.
Host: Astani CEE
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Cassie Cremeans