Laboratory Evaluation of Footings for Lunar Telescopes
Presented here are the results of laboratory experiments with different footing shapes for lunar telescopes. These experiments used a variety of soils including some to simulate regolith...
Plot-scale Field Experiment of Surface Hydrologic Processes with EOS Implications
Plot-scale hydrologic field studies were initiated at NASA Marshall Space Flight Center to a) investigate the spatial and temporal variability of surface and subsurface hydrologic processes,...
In Situ Recovery of Water from Dormant Comet Cores & CI Carbonaceous Chondrites
Water and volatiles may be produced by drill holes into dormant comet cores or class CI or CM asteroids. This is modeled after in-situ mining as in the Frasch process sulfur mines of the...
Field Verification of a Wave-Induced Current Model
A unique data set of nearshore waves and current measurements over a bar-trough bathymetry was collected during a field experiment at Duck, NC, in October 1990. These high-quality data...
Nondestructive Testing of Concrete Elements and Structures
Quality of a concrete structure depends on good construction practice. On the other hand, continuous repair and maintenance preserve the quality of construction. Nondestructive evaluation...
Laboratory Tests of Modal Emissions and Off-Cycle Corrections to FTP-75
The modeling of emissions from on-road mobile sources is an on-going process. Two broad topics which are currently under study are the evaluation of driving cycles and the development...
Implementing Uncertainty Treatment in AI Development Environment
The seismic vulnerability of existing masonry buildings is investigated by an expert system prototype. Field inspectors have to provide answers which can be of a Boolean, fuzzy or probabilistic...
Fuzzy Measures in the Knowledge Based Diagnosis of Seismic Vulnerability of Masonry Buildings
Rules based expert systems and fuzzy logic have been employed to increase the speed and the reliability of the survey of masonry buildings, to forecast their seismic vulnerability....
Structural Reliability of Seismic Isolation System
Seismic reliability analysis of isolated structure is conducted. In this study focused on are bearing capacity of isolation layer considering strength randomness of isolation bearings...
Variability Response Functions and Stochastic Field Discretization in Stochastic Finite Element Methods
Stochastic systems whose mechanical properties vary spatially are investigated in the present paper. The stochastic response variability of the systems is characterized by means of the...
Probabilistic Evaluation of Redundancy of Bridge Structures
Redundancy of bridge structures and methods to evaluate redundancy are reviewed in this paper. A method to measure redundancy based on the existing theories of probability as related to...
Development of a Limit-State Seismic Code for Bridges
The catastrophic collapse of the Cypress Street Viaduct during the Loma Prieta earthquake of October 17, 1989 and the loss of spans in both the Struve Slough Bridge and the San Francisco-Oakland...
Spatial Variability Effects on the Seismic Response of Models of Bridges
The significance of the spatial variability (spatial incoherence and apparent propagation) of the seismic ground motions on the response of bridges, modeled as three-span symmetric beams,...
Vibration Control of Highway Bridge Under Earthquakes
Seismic base isolation for highway bridges may increase relative displacement, while reducing the acceleration and base force. Elastomeric bearings with lead plug for base isolation may...
Surface Motion Due to Stochastic Plane Sources in a Layered Medium
To simulate the ground motion in the near field, a seismic fault is modeled as a two-strip plane. The width of each strip is so thin that the rupture process of the strip can be described...
Evaluation of Expansive Clay Soils in Tucson, Arizona
Research was conducted to investigate the mineralogy, engineering properties, and regional distribution of expansive clay soils in Tucson, Arizona. Data derived from X-ray diffraction...
Stochastic Modelling of Strong Ground Motions for the Istanbul, Turkey Area from Seismic Data for the Surrounding Region
The ultimate goal of this research is to obtain simulations of earthquake ground motions for the Istanbul, Turkey region. A process of earthquake analysis developed by Ellis and Cakmak...
F-K Spectra From a Haskell-Type Source in a Multiple-Layered Half-Space
Analytic expressions for the complex Fourier amplitudes of seismic ground motion at the free surface of a layered half-space are established. The seismic source is described using Haskell's...
A Stochastic Model for Crack Initiation and Fatigue Life
A stochastic theory of high cycle fatigue life is based on a combination of the theory of diffusion in the presence of a stress field with activated state theory. The result is expressed...
Truck Loading Data for a Probabilistic Bridge Live Load Model
The University of Colorado at Boulder completed a major bridge testing and analysis program for the Federal Highway Administration (FHWA). According to FHWA, this study has produced the...
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