Numerical implementation and modeling of earthquake induced landslides for slopes with soft and sensitive clay layers

Earthquake induced landslides pose a significant threat to many communities, environment and infrastructure. The potential damages could be severe in sensitive clay slope failures because the post-peak softening behaviour could cause retrogressive failure of soil blocks resulting in large-scale landslides. The failed soil blocks generally displace over a large distance during earthquake and post-quake stages. Therefore, upslope retrogression and downslope runout are two important phenomena need to be studied for better understanding of risks associated with landslides in sensitive clays. The traditional limit equilibrium methods, commonly used in slope stability analysis, cannot model retrogressive failure or deformation of slopes. The present study concentrates on development of large deformation finite element (FE) models using a Coupled Eulerian- Lagrangian (CEL) approach to simulate the failure of soft and sensitive clay slopes triggered by earthquakes. Analyses are performed for pseudostatic and dynamic loading conditions modeling the undrained behaviour of clay as elasto-plastic material with and without post-peak degradation of shear strength. A nonlinear post-peak strength degradation model as a function of accumulated plastic shear strain is implemented in FE analysis. In addition to CEL, FE analyses are performed using Lagrangian-based FE techniques to show the advantages of CEL to simulate large landslides. The CEL approach can successfully simulate the formation of shear bands (zone of accumulated shear strains), type of failure commonly observed after earthquake, upslope retrogression and downslope runout for varying geometry and soil properties

Degree Constrained Triangulation

Triangulation of simple polygons or sets of points in two dimensions is a widely investigated problem in computational geometry. Some researchers have considered variations of triangulation problems that include minimum weight triangulation, de-launay triangulation and triangulation refinement. In this thesis we consider a constrained version of the triangulation problem that asks for triangulating a given domain (polygon or point sites) so that the resulting triangulation has an increased number of even degree vertices. This problem is called Degree Constrained Triangulation (DCT). We propose four algorithms to solve DCT problems. We also present experimental results based on the implementation of the proposed algorithms. The implementation is done in Java programming language with user friendly graphical interface

Aeronautical engineering: A continuing bibliography with indexes (supplement 282)

This bibliography lists 623 reports, articles, and other documents introduced into the NASA scientific and technical information system in Aug. 1992. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles

The Use of Human Behaviour in Fire to Inform Canadian Wildland Urban Interface Evacuations

Wildland urban interface (WUI) communities are generally the most at risk of being impacted by wildfires. In order to assess the vulnerability of these communities, it is important to understand the impact that human behaviour in fire (HBiF) can have on wildfire evacuations, specifically in Canada where such data is lacking. To lay the groundwork for a comprehensive vulnerability assessment of a Canadian case study community, a conceptual model of protective action decision-making during WUI fires was created. This was used to develop a survey to understand the WUI fire awareness and experience as well as the anticipated protective actions of the case study community residents. The microsimulation software PTV VISSIM was used to model 10 evacuation scenarios to identify key evacuation modelling considerations and potential evacuation challenges faced by the community. In doing so, a framework for using HBiF to inform WUI vulnerability assessments and evacuations was developed

Aeronautical engineering: A continuing bibliography with indexes (supplement 258)

This bibliography lists 536 reports, articles, and other documents introduced into the NASA scientific and technical information system in October 1990. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics

Compendium of Yukon Climate Change science: 2002 - 2013

"The Compendium is intended to provide an overview of recent (2003-2013) climate change work involving Yukon. It is comprised of various types of documents, including scientific journal articles, government publications, workshop reports, and conference proceedings."--from Foreword

Compendium of Yukon climate change science 2003 - 2013

"The Compendium is intended to provide an overview of recent (2003-2013) climate change work involving Yukon. It is comprised of various types of documents, including scientific journal articles, government publications, workshop reports, and conference proceedings."--from Foreword

Airflow prediction in buildings for natural ventilation design : wind tunnel measurements and simulation

Natural/hybrid ventilation systems with motorized operable windows, designed and controlled to utilize the potential for cross-ventilation, represent an area of significant interest in sustainable building design as they can substantially reduce energy consumption for cooling and ventilation. Presently, there is a need for accurate prediction models that can contribute to the improvement of indoor environmental quality and energy performance of buildings, and the increased use of low energy, naturally driven cooling systems. In this regard, the present research aims to enhance airflow prediction accuracy for natural ventilation design of buildings considering advanced experimental and simulation methods. The study considers a Boundary Layer Wind Tunnel (BLWT) approach to investigate the wind-induced driving forces and ventilation flow rates in various building models subject to cross-ventilation. The Particle Image Velocimetry (PIV) technique was used for the first time to evaluate accurately the air velocity field for various cross-ventilation configurations. Detailed measurements were performed to determine mean and fluctuating internal pressures since they affect airflow prediction, occupants' thermal comfort, as well as cladding and structural wind load design of buildings with operable windows. PIV data for the inflow velocity were compared with those by using conventional techniques (e.g., hot-film anemometry) and results show differences, between the two methods, up to a factor of 2.7. This clearly indicates that accuracy can be enhanced with carefully conducted PIV experiments. The study provides guidelines for implementation of cross-ventilation in design practice. These guidelines were developed on the basis of parametric experimental investigations, which quantify the impact of relative inlet-to-outlet size and location on ventilation airflow rates and thermal comfort of building occupants. The study develops a novel simulation methodology combined with a sensitivity analysis focused on modelling issues, such as the impact of zoning assumptions, to predict the envelope pressures and related air-exchange rates in buildings due to wind, stack, and mechanical system effects. An integrated simulation tool (ESP-r) was used to model the airflow/energy interactions in an existing high-rise residential building, and simulation results agree well with monitoring data