Failure mechanism of bolting support and high-strength bolt-grouting technology for deep and soft surrounding rock with high stress

Roadway borehole pressure relief and let the pressure anchor combined support technology were based on using the new pressure high strength bolt instead of ordinary bolt ,Combined with the borehole pressure relief principle, aim at releasing high stress of surrounding rock of roadway ,Complying with the deformation characteristics of supporting technology of the surrounding rock. In this paper, we used scaled numerical simulation technology —— ADINA to analyze the roadway borehole pressure relief and let the pressure anchor coupling support technology. To the tunnel, we used the method of numerical simulation of let the pressure bolt support independently, drilling pressure relief, and borehole pressure relief and let the pressure anchor coupling support three kinds of the comparison numerical simulation. The advantages of coupling supporting effect was elaborated, It was instructive for the deeply roadway engineering in the future.

Download Full-text

Research on Supporting Technology of Roadway Driving along Next Goaf of Second Mining Strip Pillar

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.446-449.1657 ◽

2012 ◽

Vol 446-449 ◽

pp. 1657-1660

Author(s):

Wei Dong Lv ◽

Nan Nan Zhao

Keyword(s):

Abutment Pressure ◽

High Strength ◽

Main Roof ◽

Surrounding Rock ◽

Control Effect ◽

General Stability ◽

High Strength Bolt ◽

Mining Face ◽

The Stability ◽

Surrounding Rock Deformation

For roadway driving along next goaf of strip pillar second mining, being influenced by the abutment pressure of previous coal mining face and main roof breaking rotary deformation, the surrounding rock deformation is serious and the control effect of ordinary bolt supporting on the general stability of roadway driving along next goaf is poorer. According to the concrete geological and technique condition of the 2351 second mining strip pillar in Daizhuang Colliery, adopting the united support pattern combined high strength bolt of levorotatory continuous thread and anchor of low relaxation prestress, the safety of the roadway can be ensured and the stability of the roadway surrounding rocks can be improved. It is of significant reference meaning for bolting support of roadway driving along next goaf of second mining strip pillar under similar condition.

Download Full-text

Failure mechanism of surrounding rock with high stress and confined concrete support system

International Journal of Rock Mechanics and Mining Sciences ◽

10.1016/j.ijrmms.2018.01.020 ◽

2018 ◽

Vol 102 ◽

pp. 89-100 ◽

Cited By ~ 44

Author(s):

Qi Wang ◽

Bei Jiang ◽

Rui Pan ◽

Shu-Cai Li ◽

Man-Chao He ◽

...

Keyword(s):

Failure Mechanism ◽

Support System ◽

High Stress ◽

Surrounding Rock ◽

Confined Concrete

Download Full-text

Failure Mechanism and Control Techniques of Reused Roadway in an Isolated Coal Barrier Pillar

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.328.213 ◽

2013 ◽

Vol 328 ◽

pp. 213-218

Author(s):

Shuai Yan ◽

De Yu Chong ◽

Zhi Ting Han ◽

Ji Zhang

Keyword(s):

Failure Mechanism ◽

Shear Failure ◽

High Stress ◽

Coal Pillar ◽

High Strength ◽

Control Techniques ◽

Roadway Stability ◽

Barrier Pillar ◽

Fundamental Reason ◽

And Performance

Reused roadway in double-U shaped layout with an isolated barrier pillar subjects to two adjacent panels mining and has large deformation. In order to keep the reused roadway stable in its service life, numerical simulation, theoretical analysis and field observation were applied to investigate the deformation rule and failure mechanism of surrounding rock during mining period. Research results show that low strength and high stress difference environment is a fundamental reason of shear failure, different loading and unloading path in both ribs of roadway is the primary reason of asymmetric failure, and performance of bolting support is critical for the roadway stability. Therefore, control techniques of reused roadway are put forward that 1) high-strength and yielding bolts support the roof and ribs to adjust to massive convergence of roadway; 2) yielding counter-pulled cables reinforce small-pillar rib to strengthen the stability of samll coal pillar; and 3) hydraulic expansion bolts support the floor. The results have been successfully applied to a field trial.

Download Full-text

INLAND DURASPRING

Alloy Digest ◽

10.31399/asm.ad.sa0496 ◽

1998 ◽

Vol 47 (5) ◽

Keyword(s):

Fracture Toughness ◽

Tensile Strength ◽

Tensile Properties ◽

High Stress ◽

High Strength ◽

Spring Steel ◽

Fatigue Properties ◽

Light Truck ◽

Suspension Systems ◽

Spring Steels

Abstract Inland DuraSpring is a high-strength microalloyed spring steel for use in high stress coil springs for automobile and light truck suspension systems. This bar product offers significant improvements in tensile strength, fatigue properties, and fracture toughness compared to conventional spring steels. This datasheet provides information on composition, hardness, and tensile properties as well asfracture toughness and fatigue. Filing Code: SA-496. Producer or source: Ispat Inland Inc.

Download Full-text

BETHSTAR 60

Alloy Digest ◽

10.31399/asm.ad.sa0421 ◽

1986 ◽

Vol 35 (8) ◽

Keyword(s):

Fracture Toughness ◽

Yield Strength ◽

Steel Plate ◽

High Stress ◽

High Strength ◽

Heat Treating ◽

Low Carbon ◽

Bethlehem Steel Corporation ◽

Low Sulfur ◽

Minimum Yield

Abstract BethStar 60 steel plate is a high-strength product with a 60,000 psi minimum yield strength. It contains low carbon and low sulfur and has outstanding toughness, weldability and formability. It provides the design engineer with a an economical high-strength low-alloy (HSLA) grade that can be fabricated readily. Applications include weight-sensitive components subject to high stress such as frames for large off-highway haulers. This datasheet provides information on composition, physical properties, microstructure, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, and joining. Filing Code: SA-421. Producer or source: Bethlehem Steel Corporation.

Download Full-text

Experimental and numerical modeling to investigate the riverbank’s stability

SN Applied Sciences ◽

10.1007/s42452-021-04168-5 ◽

2021 ◽

Vol 3 (2) ◽

Author(s):

Asad H. Aldefae ◽

Rusul A. Alkhafaji

Keyword(s):

Numerical Simulation ◽

Failure Mechanism ◽

High Stress ◽

Physical Models ◽

Term Condition ◽

Tigris River ◽

Soil Settlement ◽

Failure Angle ◽

Dangerous Place ◽

Type Of Failure

AbstractThe purpose of this paper is to assess the failure mechanism of riverbanks due to stream flow experimentally and numerically to avoid recurring landslides by identifying the most dangerous place and treating them by a suitable method. The experiments and the physical models were carried out to study the failure mechanism of riverbank and evaluation of their stability in two cases: short-term condition and long-term condition flow where three models were tested. The Tigris River (Iraq) is considered as a model in this paper in terms of the applied velocity and modeled soil of the banks it was used at the same characteristics in the prototype scale. Also, a numerical simulation was performed using the FLOW-3D program to determine the velocity distribution and to identify the areas subjected to the high stress levels through the water flow. The obtained results in this paper are inspecting of failure mechanism types that occur under the influence of specific limits of flow velocity, which have shown good compatibility with the type of failure in the prototype scale. In addition to calculating the amount of soil erosion, the failure angle, and the amount of soil settlement at the riverbank model is investigated also. The results of experimental work and numerical simulation were well matched, where the standard error rate for Froude number ranged between (1.8%–6.6%), and the flow depth between (2.7%–6.9%).

Download Full-text

An Experimental Study of Cavity Nucleation During Superplastic Deformation

MRS Proceedings ◽

10.1557/proc-196-51 ◽

1990 ◽

Vol 196 ◽

Author(s):

Jiang Xinggang ◽

Cui Jianzhong ◽

Ma Longxiang

Keyword(s):

Grain Boundary ◽

Superplastic Deformation ◽

Thermomechanical Processing ◽

High Stress ◽

High Strength ◽

Optical Microscope ◽

Grain Boundary Sliding ◽

Cavity Nucleation ◽

High Stress Concentration ◽

Voltage Electron

ABSTRACTCavity nucleation during superplastic deformation of a high strength aluminium alloy has been studied using a high voltage electron microscope and an optical microscope. The results show that cavities nucleation is due only to superplastic deformation and not to pre-existing microvoids which may be introduced during thermomechanical processing. The main reason for cavity nucleation is the high stress concentration at discontinuties in the plane of the grain boundary due to grain boundary sliding.

Download Full-text

Study on the Truss Support Technology for Coal Side in a Soft Broken Coal Roadway Under High Stress

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.524-527.360 ◽

2012 ◽

Vol 524-527 ◽

pp. 360-363

Author(s):

Shou Yi Dong ◽

Qi Tao Duan ◽

Fu Lian He ◽

Qi Li ◽

Hong Jun Jiang

Keyword(s):

Production Condition ◽

High Stress ◽

Field Investigation ◽

Surrounding Rock ◽

Theory Analysis ◽

Large Section ◽

Cable Channel ◽

Coal Roadway ◽

Measurement Results ◽

Steel Truss

The coal side deformation and sliding can not be effectively controlled by use of the traditional bolt or cable support in the high stress crushed surrounding rock and large section roadway. For solving this problem, the new prestressed truss support technology is put forward, and its supporting principles of roof and two walls are stated. The mechanical model of cable-channel steel truss is established, and then the tensile strength of the cable and the maximum deflection of the channel steel are derived. By way of field investigation, mechanics theory analysis and actual production condition, the scheme is defined and applied in the replacement roadway. Measurement results of surrounding rock behavior show that the coal side displacement is no more than 254mm and the roof convergence is less than 172mm. Apparent economic and technical profits have been achieved.

Download Full-text