Reassessing the Risk Assessment
Risk assessments should help an engineer determine cost-effective remedies to environmental pollution. Unfortunately, most don't. Most assessments drastically overestimate...
VOCs: The New Effluent
The Clean Air Act of 1990, in addition to many state and local regulations, has officials of publicly-owned treatment works (POTWs) shifting their focus, and funds, to air toxic emissions...
Dynamic Compaction of Nuclear Waste
When ponding, caused by settlement of the original soil cover over low-level nuclear waste buried at the Department of Energy's Savannah River Nuclear Plant near Aiken, S.C.,...
Cleaning Up Chromium
From 1956 to 1985, the United Chrome Products plant in Corvallis, Oregon, took a steady toll on the environment. Leaky plating tanks and the discharge of rinse water into a disposal pit...
Controlling Nitrogen in Coastal Waters
Excess nitrogen in coastal waters is becoming a problem worldwide. Nutrients such as nitrogen come from sewage treatment plants, septic tanks, runoff from fertilizer and animal waste,...
Grouting, Soil Improvement and Geosynthetics
The proceedings of the 1992 ASCE Specialty Conference on Grouting, Soil Improvement and Geosynthetics, addresses advances in the state-of-practice, research and technological developments...
A New Era In Transportation
Its passage into law was about as smooth as a rush-hour traffic jam, but the surprising thing about the new Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) is that it...
Automating The Corps
Automated soil testing machines solved several problems at once for the U.S. Army Corps of Engineers' South Western Division Laboratory in Dallas, Texas. The machines replaced...
Geomechanics of Subsidence Due to Pumping of Groundwater
In this talk we describe a nonlinear theory for the classical problem of pumping of groundwater from a layered soil. The model soil system consists of three horizontal layers where a very...
On the Diffusional Stress Transmission
A probabilistic diffusional mechanism for the propagation of intergranular forces has been formulated as a set of three mathematical assumptions. The equilibrium equations are complemented...
Particle Analysis of Material Behavior?A Note on Continuum Assumptions
Continuum models of materials have dominated our approach to the analysis of material behavior. Recently a number of discrete particle methods have been proposed which offer a different...
Soil Behavior from Unconventional Loading Conditions
Random and sinusoidal loading conditions were used in this study to determine the soil moduli and the damping ratios of cohesive soil samples. Test results showed some differences between...
Experimental Photoelastic Analysis of Tunnels Containing Cracks
Due to the presence of cracks the strength of the structure is decreased in the present paper an experimental two dimensional photoelastic technique has been developed to analyze the circular...
Instability of Slopes with Nonassociated Flow
Experimental investigations of the conditions for instability have shown that granular materials may become unstable inside the failure surface. For states of stress below the failure...
Analysis of Internal Discontinuities in Geo-Materials
A new approach for modeling localized deformations is proposed. This approach uses an interface element to model the shear band. A successful capture of the kinematics of a failure mechanism...
Neural Network Modeling of the Mechanical Behavior of Sand
Given a set of triaxial test data, an artificial neural network (ANN) has been trained to model the mechanical behavior of a medium-to-fine sand. Once trained, the ANN was tested by simulating...
Computer Simulation of Direct Shear Test
This paper presents a pilot study of a computer simulation of direct shear test on sands using the Discrete Element Method. The numerical test setup is described first, which is followed...
Constitutive Modeling for Material with Perfect Disordered Heterogeneity
Finite element analysis with large number of elements are performed to simulate perfect disordered heterogenous material. The probabilistic nature of the micromechanical behavior of the...
Interaction Between Soil and a Rigid Foundation in a Layered Medium: A New Analytical Approach
This paper is concerned with derivation of the impedance matrix for the problem of interaction between soil and an embedded rigid foundation in a layered medium. As an approximation, the...
Dynamic Response Analysis of Pile Foundations by Using Variational Calculus
Various approaches have been developed for the frequency-domain dynamic response analysis. The one proposed by M. Novak (1974) is simplest of all and yet produces the results very close...
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