A new energy-absorbing bolt for rock support in high stress rock masses

2010 ◽  
Vol 47 (3) ◽  
pp. 396-404 ◽  
Author(s):  
Charlie Chunlin Li
Keyword(s):  
High Stress ◽  
Rock Masses ◽  
Rock Support ◽  
New Energy ◽  
Energy Absorbing

A New Yielding Bolt for Rock Support in High Stress Rock Masses

2012 ◽  
Vol 204-208 ◽  
pp. 366-369 ◽  
Author(s):  
Gang Wang ◽  
Xue Zhen Wu ◽  
Yu Jing Jiang
Keyword(s):  
Rock Mass ◽  
Theoretical Analysis ◽  
Large Deformations ◽  
High Stress ◽  
Surrounding Rock ◽  
Rock Support ◽  
Stability Of Surrounding Rock ◽  
History Of ◽  
The Stability ◽  
Energy Absorbing

High stress in the surrounding rock mass causes serious stability problems. The applied support system used in this conduction should be able to carry high loads and also accommodate large deformations without experiencing serious damage. In this paper, a brief overview of the history of yielding/energy-absorbing rock bolts is provided. And then, a new yielding bolt invented by the author is introduced in detail, including its layout and principle. Theoretical analysis shows that the bolt has large load-bearing and deformation capacities, thereby absorbing a large amount of energy to maintain the stability of surrounding rock.

scholarly journals Investigation of Energy-Absorbing Properties of a Bio-Inspired Structure

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 881
Author(s):  
Adrian Dubicki ◽  
Izabela Zglobicka ◽  
Krzysztof J. Kurzydłowski
Keyword(s):  
Absorption Capacity ◽  
Compression Tests ◽  
Element Analysis ◽  
Lightweight Structures ◽  
New Energy ◽  
Absorbing Material ◽  
Lightweight Structure ◽  
3D Printed ◽  
Deformation Force ◽  
Energy Absorbing

Numerous engineering applications require lightweight structures with excellent absorption capacity. The problem of obtaining such structures may be solved by nature and especially biological structures with such properties. The paper concerns an attempt to develop a new energy-absorbing material using a biomimetic approach. The lightweight structure investigated here is mimicking geometry of diatom shells, which are known to be optimized by nature in terms of the resistance to mechanical loading. The structures mimicking frustule of diatoms, retaining the similarity with the natural shell, were 3D printed and subjected to compression tests. As required, the bio-inspired structure deformed continuously with the increase in deformation force. Finite element analysis (FEA) was carried out to gain insight into the mechanism of damage of the samples mimicking diatoms shells. The experimental results showed a good agreement with the numerical results. The results are discussed in the context of further investigations which need to be conducted as well as possible applications in the energy absorbing structures.

scholarly journals Minor Structures for the Improvement of Wave Disturbance in a Small Harbor

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
A. Sulis
Keyword(s):  
Boussinesq Equations ◽  
Wave Disturbance ◽  
Comprehensive Description ◽  
New Energy ◽  
Efficient Alternative ◽  
Operational Activities ◽  
Traditional Structures ◽  
Energy Absorbing ◽  
Incident Waves ◽  
Large Research

A very important aspect in the planning, design, and maintenance of a harbor is to determine the response of the harbor basin to incident waves. The Saras harbor in South Sardinia (Italy) has been experiencing significant wave disturbance that affects the safety of mooring and operational activities. In the framework of a large research, this paper summarises a comprehensive description of new energy absorbing structures that can be seen as an efficient alternative to more traditional structures when limited by economic or technical constraints. Specifically, the paper presents the results of a graphical preliminary approach and a numerical modelling that solves the enhanced Boussinesq equations in two horizontal dimensions.

New Energy-Absorbing High-Speed Safety Barrier

2003 ◽  
Vol 1851 (1) ◽  
pp. 53-64 ◽  
Author(s):  
John D. Reid ◽  
Ronald K. Faller ◽  
Jim C. Holloway ◽  
John R. Rohde ◽  
Dean L. Sicking
Keyword(s):  
High Speed ◽  
Steel Tube ◽  
Full Scale ◽  
Element Analysis ◽  
Dynamic Component ◽  
Testing Program ◽  
Roadside Safety ◽  
New Energy ◽  
University Of Nebraska Lincoln ◽  
Energy Absorbing

For many years, containment for errant racing vehicles traveling on oval speedways has been provided through rigid, concrete containment walls placed around the exterior of the track. However, accident experience has shown that serious injuries and fatalities may occur through vehicular impacts into these nondeformable barriers. Because of these injuries, the Indy Racing League and the Indianapolis Motor Speedway, later joined by the National Association for Stock Car Auto Racing (NASCAR), sponsored the development of a new barrier system by the Midwest Roadside Safety Facility at the University of Nebraska–Lincoln to improve the safety of drivers participating in automobile racing events. Several barrier prototypes were investigated and evaluated using both static and dynamic component testing, computer simulation modeling with LS-DYNA (a nonlinear finite element analysis code), and 20 full-scale vehicle crash tests. The full-scale crash testing program included bogie vehicles, small cars, and a full-size sedan, as well as Indy Racing League open-wheeled cars and NASCAR Winston Cup cars. A combination steel tube skin and foam energy-absorbing barrier system, referred to as the SAFER (steel and foam energy reduction) barrier, was successfully developed. Subsequently, the SAFER barrier was installed at the Indianapolis Motor Speedway in advance of the running of the 2002 Indianapolis 500 race. From the results of the laboratory testing program as well as analysis of the accidents into the SAFER barrier occurring during practice, qualification, and the race, the SAFER barrier has been shown to provide improved safety for drivers impacting the outer walls.

Deformations, failures of deep high stress rock masses and its stability

2004 ◽  
pp. 463-466
Author(s):  
Fengtian Yue ◽  
Peng Shao ◽  
Yongnian He
Keyword(s):  
High Stress ◽  
Rock Masses

Deformations, failures of deep high stress rock masses and its stability

2004 ◽  
pp. 463-466
Author(s):  
Yongnian He ◽  
Peng Shao ◽  
Fengtian Yue
Keyword(s):  
High Stress ◽  
Rock Masses

scholarly journals A critical review on the developments of rock support systems in high stress ground conditions

2020 ◽  
Vol 30 (5) ◽  
pp. 555-572 ◽  
Author(s):  
Masoud Ghorbani ◽  
Korosh Shahriar ◽  
Mostafa Sharifzadeh ◽  
Reza Masoudi
Keyword(s):  
Critical Review ◽  
Support Systems ◽  
High Stress ◽  
Rock Support ◽  
Ground Conditions

The Energy Balance Concept of Hydraulic Fracturing

1968 ◽  
Vol 8 (01) ◽  
pp. 1-12 ◽  
Author(s):  
T.K. Perkins ◽  
W.W. Krech
Keyword(s):  
Energy Balance ◽  
Stress Distribution ◽  
Hydraulic Fracturing ◽  
High Stress ◽  
Fluid Pressure ◽  
Leading Edge ◽  
Energy Balance Equation ◽  
Surface Energies ◽  
New Energy ◽  
Laboratory Models

Abstract This paper explains the concept of a damaged region arising from high stress concentration at the leading edge of a hydraulically created fracture. Approximate stresses near the tip of the crack are calculated, and it is shown that a stable crack shape is possible for which all stresses are finite. A new energy balance is derived incorporating these thoughts, and it is shown that predicted fracturing pressures (using surface energies determined by cleavage) agree with experimental fracturing pressures determined in models. All calculations apply to the case of a nonpenetrating fluid. It is concluded from these studies that in some cases, particularly in small laboratory models, these phenomena significantly affect extension pressures and crack widths. Introduction One of the perplexing questions about hydraulic fracturing that has not been satisfactorily answered is, what pressure is necessary to extend a fracture? For many engineering problems involving failure, it is sufficient to calculate those loading conditions which would bring a stress or elastic strain within the material to a level that could not be tolerated. However, this approach is not useful when considering a sharp-edged crack; calculated stresses and elastic strains always reach infinitely large values near the tip of the crack if fluid pressure is applied all the way to the crack extremity. This difficulty has led to the concept of cohesiveness or absorption of surface energy, implying that behavior near the tip of the crack is not purely elastic. Additional note of the nonideal behavior of rocks will be made in this paper. Then, by simplifying and dealing with an average stress in an inelastic region, the approximate stress distribution around a hydraulic fracture will be calculated and the conditions under which a stable fracture can exist will be shown. A new energy balance equation is then derived incorporating the modified stress picture. Finally, predicted fracture extension pressures are compared with breakdown pressures obtained in laboratory models. This comparison shows that surface energies measured by the cleavage technique are consistent with those values manifested during fracture extension. PROBLEMS OF INDUCED STRESS It will be revealing to consider first the calculated stresses around a penny-shaped line crack, assuming that the rock behaves as a linear, elastic material. Fig. 1 shows the stress distribution in the plane of the crack as calculated with Sneddon's equation. If pressure p is applied uniformly within the crack, then infinitely large tensile stresses would be induced in the rock near the crack tip. Such stresses could not be sustained in a real material. Two approaches have been proposed to explain this dilemma. SPEJ P. 1ˆ

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