Modeling Gravity-Driven Fingering in Rough-Walled Fractures Using Modified Percolation Theory
Pore scale invasion percolation theory is modified for imbibition of wetting fluids into fractures. The effects of gravity, local aperture field geometry, and local in-plane air/water...

Wetting Front Instability in an Initially Wet Unsaturated Fracture
Experimental results exploring gravity-driven wetting front instability in a pre-wetted, rough-walled analog fracture are presented. Initial conditions considered include a uniform moisture...

Crack and Contact Problems in Masonry Arch Bridges
A two-dimensional finite element program has been developed to predict the load carrying capacity of masonry arch bridges with different structural defects such as missing bricks and tangential...

Computer Aided Analysis/Design of Overlays in Cracked Road Pavements
In this contribution CAPA, a user-friendly, PC based, finite element system, capable of analyzing and dimensioning pavement overlays is presented. Because of the generality of the finite...

Integrating Qualitative and Quantitative Reasoning in Structural Engineering
Qualitative reasoning has applications in engineering problem solving and the development of intelligent computer-aided engineering tools. Most applications in structural engineering have...

Algorithm for Crack Detection in Automated Pavement Analysis
This paper summarizes recent research in various algorithms for detection of pavement cracks. The most successful algorithms use a digital filter to obtain an approximation of the principal...

Evaluation of Two Automated Thresholding Techniques for Pavement Images
Thresholding of pavement images is an important step towards the design of an automated pavement crack detection system. However, traditional automated thresholding techniques generally...

New Wells Safeguard Scenic Tahoe
Surface water for drinking and for snow-making is becoming scarce in the Lake Tahoe region, along the California and Nevada border. New Environmental Protection regulations regarding surface...

Crevasses on the Lower Course of the Mississippi River
Before construction of artificial levees, crevasses were a common event along the Mississippi River. They directed sediment out of the main channel and reduced flood stage down river....

Non-Intrusive Crack Detection in Clay Landfill Cover Liners
Laboratory and field studies were conducted to demonstrate that the azimuthal variation in electrical resistivity can be used to indicate the presence of cracks in clay systems. Laboratory...

Bending of Retrofitted Test Foundation Walls
New repair methodology has been developed for residential construction that can be used to retrofit foundation bearing walls damaged by mine subsidence. The repair strengthens the foundation...

Recent Developments in Composite Bridge Building in Germany
In the 1980s a movement started to build composite bridges with reinforced concrete slabs and to renounce to prestress them in one or both directions. This type of bridge is advantageous...

How SHRP Reliably Predicts Pavement Performance
One of the important results of the SHRP Asphalt Research Program was to develop a comprehensive pavement performance model that reliably predicts rutting, fatigue cracking and thermal...

Automated Crack Detection System Implementation in ARAN
An automated road surface crack detection system has been integrated into the Automated Road Analyzer (ARAN). The acquisition system features controlled lighting through strobe lights...

Survey: Fundamental Pavement Crack Imaging Algorithms
Many algorithms for distinguishing pavement cracks from background noise are based on the geometric characteristics of noise, such as shape and size. The objective of this paper is to...

Heavy Aircraft Damage to Rigid Airport Pavements
A theoretical solution is presented for the damage caused by heavy aircraft at the transverse joints in a rigid airport pavement. Large stresses in the subgrade generate significant permanent...

Evaluation and Overlay Design of Airport Pavements
Heavy weight deflectometer (HWD), a heavier version of the falling weight deflectometer, enables detailed evaluation of airport pavements to be performed using a rapid a non-destructive...

Fracture Mechanics
This brief report, prepared by ACl 447 Subcommittee 2, reviews recent advances in finite element modeling of fracture and damage in concrete structures. The fundamentals of the fracture...

Reinforced Concrete
Recent developments and procedures used to model reinforced concrete using finite element analysis are summarized. Special emphasis is placed on the results of a survey of papers published...

Computational Aspects
In the past, two distinctly different approaches - smeared and discrete failure models have been adopted to describe failure mechanisms in plain and reinforced concrete structures. Although...

 

 

 

 

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