Recent Experience With Armor Stone Cracking in the Buffalo District
Accelerated deterioration of large armor stone on the Cleveland East Breakwater, Cleveland, Ohio has resulted in the need for more intensive monitoring of the entire armor stone production...
Learning to Love NDT
Sometimes overblown claims and the practical limitations of early nondestructive tests for concrete have left many civil engineers leery of NDT methods. While some are aware that NDT has...
Staffing Up for a Major Program
A nine-member construction management section must pilot a $335 million, multi-project capital improvement program over the next five years. Should construction management duties automatically...
Making Teamwork Work
From consulting firms to steel workers, most work groups would benefit enormously from developing better teamwork, but making it happen isn't easy. Excerpts from
Project Management: Keys to Success
Successful construction projects can be traced to several key factors observed by the owner, the AE and the contractor. They include: 1) Goals and commitment of the managing partners agreed...
Actively Controlled P-F Based Sliding Structures
This study summarizes about three years of research effort related to active control of sliding structures to both harmonic and strong earthquake type motions. This is the first time such...
Bifurcations and Chaos in Structural Control
We study a harmonically forced oscillator with nonlinear soft spring subjected to a linear feedback control with time delay. This system can be written as a three dimensional dynamical...
Effect of Active Control on Closely Spaced Natural Frequencies
Current problems in structural control involve structures with closely spaced natural frequencies (M.J. Balas, 1983). The purpose of this paper is to show how control affects a structure...
Full Scale Application of Active Bracing Systems
A full scale active bracing system has been installed in a structure in Tokyo, Japan. The practical problems associated with the implementation of this system, and the corresponding solutions...
Interaction Effects in the Hybrid Control of Euler-Bernoulli Beams
The effect of viscous and Voigt damping upon the open loop response of simple continua such as Euler-Bernoulli beams is well understood. However, when attempting to control a distributed...
Recent Findings in Active Structural Control
Over the past decade, tremendous advancements have been made in the development of structural control paradigms and in the necessary supporting technologies. The fundamental paradigm that...
Structural Control Under Stochastic Seismic Loads
This paper presents a method of controlling nonlinear and hysteretic civil engineering structures subjected to stochastic earthquake ground excitations. Emphasis is placed on control of...
Performance-Based Evaluation of Lunar Base Construction Equipment and Methods
Existing literature regarding the selection of lunar base construction equipment and methods is heavily dependent upon qualitative measures for evaluation of equipment concepts. Selection...
Modular Robot Testbed
One approach to non-terrestrial construction involves the use of small, inexpensive, modular robots rather than expensive one-of-a-kind construction tools. The Modular Robots Testbed at...
Architectures for Mission Control at the Jet Propulsion Laboratory
One of the most vital, but often overlooked, research areas for space missions is flight operations. The imbalance is caused by many factors. Among them, the manner in which space missions...
Extraction of Potable Water from Urine for Space Applications
A regenerative technology capable of managing water and wastewater on-board long-term manned space platforms is essential if the Bush Administration's Space Exploration Initiative (SEI)...
Thermal Investigation of a Large Lunar Telescope
Recent interest in construction of a large telescope on the Lunar surface (Nein and Davis, 1991; Bely, Burrows, and Illingworth, 1989) has prompted this feasibility study of a thermal...
A Systems Approach to Water Recycling Research
Because of the cost of Earth resupply, water recycling from wastewater is a critical enabling technology for long duration space missions. The need and the fact that water quality is not...
The Design and Use of Flow-Through Hold Pads
The Chicago Delay Task Force recommended the construction of nine largescale, flow-through hold pads at Chicago O'Hare International Airport to reduce the potential for airfield gridlock....
Fine Tuning the Airfield: The New Denver International Airport
This paper discusses airfield layout considerations that have been incorporated into the design of the new Denver International Airport (DIA). These concepts include some unique provisions...
Return to search