Hydraulic Fracturing in Embankment Dams
There is now sufficient evidence to conclude that concentrated leaks occur commonly through the impervious sections of embankment dams by hydraulic fracturing without being observed, even...

Fracture and Fragmentation of Rock Materials by Explosives
Explosives are used in various commercial applications including the extraction of natural resources from the earth and removal of materials for new construction. These applications include...

Fracture Mechanics Analysis of Massive Hydraulic Fracturing Containment
The hydraulic fracturing containment problem is the subject of the present investigation. Unlike previous studies, the interface crack geometry with the correct crack tip singularity was...

Modelling of the Fracture Process Zone in Rock
There are a number of situations in the fracture mechanics of rock in which linear elastic fracture mechanics (LEFM) concepts are inapplicable or insufficient. Two such situations are...

Nonlinear Fracture Process Zone in Rock
A study of the fracture process zone was conducted to gain an understanding of the physics of crack propagation in rock. The nondestructive testing technique of acoustic emissions was...

Oil Shale Fracture Characterization by a New Model
Fracture toughness of oil shale is a property which is essential for fracture characterization needed for energy resource development and recovery. However, a data base for fracture toughness...

Simulation of Rock Fracture with the 3-D SHALE Code
The 3-D SHALE code simulates the propagation of stress waves and the occurrence of fracture in brittle solids. The physical models and numerical methods in this code are similar to those...

Hundreds of Bridges�Thousands of Cracks
In the past 10 years hundreds of welded steel bridges, most of them relatively new, have suffered thousands of cracks due to secondary stresses, that is, the cracks are caused by deflections...

Nonlinear Macroscopic Finite Element Model for Masonry Walls
A macroscopic finite element model which includes both transverse shear effects and nonlinearity due to cracking has been developed for masonry. These features are accommodated using a...

Tensile Fracture and Fatigue of Cement Stabilized Soil
Portland cement stabilized soil is widely used as a base material for roads, airfields, and similar structures. Cracking in this material is studied using fracture mechanics concepts....

Analysis of Cracking of I79 Bridge at Neville Island
A large crack was discovered to form in a girder of the I-79 Glenfield Bridge over the back channel of the Ohio River near Pittsburgh on January 28, 1977. A section of the girder containing...

Structural Integrity Assessment of the Flexible 870 Advanced Design Bus
The Grumman Flxible 870, a lightweight advanced design urban bus, entered service in Atlanta, GA in 1978, and some 2,800 of these buses were in service nationwide by 1980. In the autumn...

Prestress and Cracking Problems in Concrete Structural Components of an Elevated Rail Transit Guideway System
In 1983 the Department of Transportation evaluated the quality of construction of selected structural components on the Dade County Transportation Administration METRORAIL elevated guideways....

Investigation of Catastrophic Failure of a Premium-Alloy Railroad Rail
In November 1983 an Amtrak train derailed at a speed of 72 mph (115 kph) at Woodlawn, Texas (in the vicinity of Marshall, Texas), resulting in four fatalities and twenty-four serious injuries....

Time-Dependent Damage and Creep of Brittle Rock
In this paper, some results of a combined analytical-experimental study of the relationship between subcritical microcrack growth due to stress corrosion and the time-dependent deformation...

Effect of Steel Fibers on the Cracking Behavior of Reinforced Concrete Continuous Beams
A research program was conducted with the aim of studying the cracking behavior of reinforced concrete continuous beams, as it is affected by using different combinations of main steel...

Time Rated Infiltrated Depth Families
A new set of infiltration families has been developed, for 'normal' soils to describe cumulative infiltrated depth versus time. This new family of curves is described...

Fracture Problems in the Transportation Industry
Six cases of damage tolerance assessment are presented, involving structures or vehicles in the U.S. transportation industry. Damage tolerance means arranging design, maintenance, and...

Superplasticized Concrete Takes Off in Dallas
Some engineers are calling superplasticized concrete the most important advance in concrete technology in over three decades. Over the past four years superplasticized concrete has begun...

An Improved Design for Grain Storage Tanks Solves Problem of Brittle Failures
The welded tank features fracture-tough steel and tube stiffeners to overcome problems evident in several failures of major tanks in recent years. Used extensively for grain storage in...

 

 

 

 

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