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Full-Text Articles in Construction Engineering and Management

Intelligent Controller For Smart Base Isolation Of Masonry Structures, Simon Laflamme, T.Y. Yu, Jerome J. Connor Oct 2009

Intelligent Controller For Smart Base Isolation Of Masonry Structures, Simon Laflamme, T.Y. Yu, Jerome J. Connor

Simon Laflamme

In this paper, an intelligent controller to control a smart base-isolated masonry structure is proposed. The smart base isolation consists of rubber bearings and a magnetorheological damper. This semi-active scheme takes advantage of the low power requirement of magnetorheological devices to achieve structural control. The controller is capable of mapping the behaviour of the controlled structure sequentially, using a self-organizing neural network which has time-varying learning rates. This neurocontroller is augmented by a sliding mode controller to account for the uncertainty on the semi-active damping forces. Wavelets are used as functions in the single hidden layer for their capability of …


Optimization Of Two-Way Post-Tensioned Concrete Floor Systems, Gaelyn B. Krauser Oct 2009

Optimization Of Two-Way Post-Tensioned Concrete Floor Systems, Gaelyn B. Krauser

Master's Theses

This thesis investigates a parametric study of a flat plate floor system designed using post-tensioning. The load balanced by the post-tensioning, the slab depth, and the strength of concrete were varied to create the parametric study of a hotel/condominium grid layout. In order to perform the parametric study, research was conducted on the development of post-tensioning, methods of analysis for two-way slab design, and post-tensioning methods of analysis. Design was conducted by hand through a series of Excel spreadsheets and compared to results found using the computer analysis program, ADAPT-PT. The designs found in the parametric study were then used …


Hot Mix Asphalt Longitudinal Joint Evaluation, Annette Porter May 2009

Hot Mix Asphalt Longitudinal Joint Evaluation, Annette Porter

Civil Engineering Undergraduate Honors Theses

Longitudinal joints are the portion of the road where two lanes meet and are formed because the lanes are paved at different times. Longitudinal joints tend to be the weakest portion of the roadway, and yet few regulations exist to control their quality. Currently, Arkansas specifications for asphalt pavement do not include any requirements for the measurement of joint quality. The purpose of this research project is to determine the most effective method for evaluating longitudinal joints in hot-mix asphalt (HMA) pavements. Most of the literature concerning longitudinal joints focuses on density as the determining factor of quality because density …


State Dependent Properties Of Rail Pads, Sakdirat Kaewunruen, Alexander Remennikov Apr 2009

State Dependent Properties Of Rail Pads, Sakdirat Kaewunruen, Alexander Remennikov

Faculty of Engineering - Papers (Archive)

Rail pad is one of the main components in ballasted railway track systems. It is inserted between the rail and the sleeper to attenuate dynamic wheel/rail interaction forces, preventing the underlying railway track components from excessive stresses. Generally, the dynamic design of tracks relies on the available data, which are mostly focused on the structural condition at a specific toe load. Recent findings show that track irregularities could significantly amplify the loads on railway tracks. This phenomenon gives rise to a concern that the rail pads may experience higher deterioration rate than anticipated in the past. On this ground, an …


Impact Damage Classification Of Railway Prestressed Concrete Sleepers, Sakdirat Kaewunruen, Alexander Remennikov Jan 2009

Impact Damage Classification Of Railway Prestressed Concrete Sleepers, Sakdirat Kaewunruen, Alexander Remennikov

Alex Remennikov

Commonly, railway tracks suffer with the extreme loading conditions, which are attributed to the train operations with either wheel or rail abnormalities such as flat wheels, dipped rails, etc. These loads are of very high magnitude but short duration, as well as they are of low-possibility occurrence during the design life of the prestressed concrete sleepers. In spite of the most common use of the prestressed concrete sleepers in railway tracks, their impact responses and behaviours are not deeply appreciated nor taken into the design consideration. Up until recently, a new limit states design approach, whereas the dynamic effects are …


Structural Behaviour And Analysis Of A Steel-Concrete Balcony Bracket, Sean Carroll Jan 2009

Structural Behaviour And Analysis Of A Steel-Concrete Balcony Bracket, Sean Carroll

Theses

For commonly used moment connections, such as the various types of beam to column endplates, a large amount of information in relation to testing data and suggested design methods exist. Engineers can use this information to safely design such connections. When developing new and unique types of connections however, usually no prior testing information is available to engineers due to the unique design. At the present time, the most effective method of designing and developing any structural element or connection is through testing. Testing and detailed analysis of the results gives factual information on the behaviour of the structure, which …