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...
On Deciding Between the Use of Engineering Standards and Risk Analysis
Risk analysis offers advantages for the optimal design and maintenance of infrastructure, but it is not always practical to apply due to the nature of certain types of infrastructure....
Optimal Allocation of Resources in Repair and Maintenance of Bridge Structures
The structural design process, examined in its entirety (and taking into account the uncertainty and randomness that characterize the governing parameters) is a decisional process, involving...
Probabilistic Analysis of Post-Tensioned Steel Girder Bridges
External post-tensioning is used as a means of strengthening existing steel girder bridges. Since absolute safety of structures is impossible to attain due to uncertainty in load and resistance,...
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...
Vibration of a Bridge Under a Random Train of Moving Loads
The vibration of a beam resulting from the passage of moving loads is a problem of great importance in structural dynamics. A consistent model for the description of the loads acting on...
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...
Reliability Model for Bridge Columns under Seismic Loads
This paper develops a model for the analysis of the reliability of bridge columns under earthquake loads. Probability of failure is defined as the probability that the displacement ductility...
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...
Experimental Study of the Transient Temperature Distributions in Concrete
A small scale, preliminary experimental effort to quantify the randomness of the thermal diffusivity of concrete has been undertaken. Two sets of cylinders have been instrumented with...
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...
Response of Suspension and Deck Arch Bridges to Spatially Varying Ground Motion
Recent awareness of the spatial variation of earthquake ground motion has caused concern about the safety of large engineered structures under seismic excitation. The effects of spatially...
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...
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