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Soil Behavior Under Blast Loading, Jichong An
Soil Behavior Under Blast Loading, Jichong An
Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research
Understanding the behavior of soil under blast loading is very important to engineers in mining, tunneling, and military construction. Due to the very complex structure of a soil mass it is very difficult to describe its constitutive relation, especially when it has different water contents and it is under blast loading conditions. New protective system designs subjected to blast loading need to be proved its validation prior to predict effect of explosive before implementation. Full-scale, buried explosive tests are costly. Finite element simulations play a significant role in the design of protective systems, for example a bottom platform of lightweight …
Progressive Failure Simulation Of Security Cable Barriers, Christopher Y. Tuan, Ratul D. Sarmah, Alexander Y. Tuan, Ching-Sheng Kao, Q. S. Li
Progressive Failure Simulation Of Security Cable Barriers, Christopher Y. Tuan, Ratul D. Sarmah, Alexander Y. Tuan, Ching-Sheng Kao, Q. S. Li
Civil Engineering Faculty Publications
Perimeter security cable barriers are widely used by various agencies all over the world to defeat threat vehicle penetration. New barrier designs require crash test validation prior to implementation. Full-scale vehicular crash tests are costly, whereas designs via finite element simulations are time consuming and require specialized skills. Based on full-scale crash tests, an innovative and simple algorithm has been developed to model the progressive failure of security cable barriers. A multi-body approach based on the first principles of physics was developed to substantially reduce computer runtime. The solution algorithm uses a large number of small time steps. Nonlinear vehicle …
Improving Analytical Travel Time Estimation For Transportation Planning Models, Chenxi Lu
Improving Analytical Travel Time Estimation For Transportation Planning Models, Chenxi Lu
FIU Electronic Theses and Dissertations
This dissertation aimed to improve travel time estimation for the purpose of transportation planning by developing a travel time estimation method that incorporates the effects of signal timing plans, which were difficult to consider in planning models. For this purpose, an analytical model has been developed. The model parameters were calibrated based on data from CORSIM microscopic simulation, with signal timing plans optimized using the TRANSYT-7F software. Independent variables in the model are link length, free-flow speed, and traffic volumes from the competing turning movements. The developed model has three advantages compared to traditional link-based or node-based models. First, the …
Reliability-Based Underseepage Analysis In Levees Using Monte Carlo Simulation, Lourdes Polanco
Reliability-Based Underseepage Analysis In Levees Using Monte Carlo Simulation, Lourdes Polanco
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
A new method for assessing the potential for unsatisfactory levee performance due to underseepage is presented. Specifically, the method assesses the potential for the initiation of piping (the internal backward erosion of the foundation or embankment caused by seepage). Current assessment methods consist of deterministic seepage analyses and simplified reliability methods. Deterministic methods produce either a maximum hydraulic exit gradient or a Factor of Safety against piping but they do not account for high levels of uncertainty in soil properties and subsurface geometry that are inherent to many levee analyses. The most common simplified reliability approaches that are currently being …
Simulation Of Traffic Loading On Highway Bridges, Bernard Enright
Simulation Of Traffic Loading On Highway Bridges, Bernard Enright
Other resources
This work is based on weigh-in-motion measurements for approximately three million trucks obtained from sites in five European countries. Techniques have been developed, supported by photographic evidence, for filtering the measurements to identify and remove unreliable values, and for the classification of extremely heavy vehicles. The collected measurements have been used as the basis for building and calibrating a Monte Carlo simulation model for bridge loading. Two-lane traffic is simulated – either two lanes in the same direction or one lane in each direction. The model allows for vehicles that are both heavier and have more axles than in the …
Site Specific Modelling Of Traffic Loading On Highway Bridges, Bernard Enright, Eugene J. Obrien
Site Specific Modelling Of Traffic Loading On Highway Bridges, Bernard Enright, Eugene J. Obrien
Conference papers
Accurate traffic loading models based on measured weigh-in-motion (WIM) data are essential for the accurate assessment of existing bridges. Much work has been published on the Monte Carlo simulation of single lanes of heavy vehicle traffic, and this can easily be extended to model the loading on bridges with two streams of traffic in opposing directions. However, a typical highway bridge will have multiple lanes in the same direction, and various types of correlation are evident in measured traffic, such as groups of very heavy vehicles travelling together and heavy vehicles being overtaken by lighter ones. These traffic patterns affect …
The Influence Of Correlation On The Extreme Traffic Loading Of Bridges, Eugene J. Obrien, Bernard Enright, A. T. Dempsey
The Influence Of Correlation On The Extreme Traffic Loading Of Bridges, Eugene J. Obrien, Bernard Enright, A. T. Dempsey
Conference papers
Accurate traffic loading models based on measured data are essential for the accurate assessment of existing bridges. There are well-established methods for the Monte Carlo simulation of single lanes of traffic, and this can easily be extended to model the loading on bridges with two independent streams of traffic in opposing directions. However, a typical highway bridge will have multiple lanes in the same direction, and various types of correlation are evident in measured traffic. This paper analyses traffic patterns using multi-lane WIM data collected at two European sites. It describes an approach to the Monte Carlo simulation of this …
Importance Of The Tail In Truck Weight Modeling For Bridge Assessment, Eugene J. Obrien, Bernard Enright, Abraham Getachew
Importance Of The Tail In Truck Weight Modeling For Bridge Assessment, Eugene J. Obrien, Bernard Enright, Abraham Getachew
Articles
To predict characteristic extreme traffic load effects, simulations are sometimes performed of bridge loading events. To generalize the truck weight data, statistical distributions are fitted to histograms of weight measurements. This paper is based on extensive WIM measurements from two European sites and shows the sensitivity of the characteristic traffic load effects to the fitting process. A semi-parametric fitting procedure is proposed: direct use of the measured histogram where there are sufficient data for this to be reliable and parametric fitting to a statistical distribution in the tail region where there are less data. Calculated characteristic load effects are shown …