In this work, the interaction between the semi-circular space and the neighboring joint with and without the presence of rock bolts was investigated using the particle flow code (PFC) approach. For this purpose, firstly, the calibration of PFC was performed using both the Brazilian experimental test and the uniaxial compression test. Secondly, a numerical model with the dimension of 100 m...

Two titanium alloy wing attachment bolts from a commercial jetliner failed during the course of a routine service operation. Failure of the bolts occurred during the re-torque process as the wing was being reattached. Metallurgical failure analysis indicated that the fracture mechanism was ductile overload and that the mechanical properties of the bolts were consistent with exemplar bolts that ...

The focus of this paper is the thick soft rock mass roof track roadway in No. 3606 panel Chaili Coal Mine. Due to its substantial thickness, susceptible damage and deformation during mining process. In order preserve integrity roof, a full anchor cable support scheme proposed after studying mechanism bolt-anchor support. supporting parameters feasibility were determined through experience numer...

Abstract Using the spatial structure of external staggered split-level panel layout, a combined support technology for adjacent roadways was developed and analyzed rock bolt anchor cable mechanism. The influence side parameters on mechanical properties anchorage body stress distribution lateral coal were revealed using FLAC 3D software. optimal bolts cables subsequently determined, effect gob-s...

We describe a procedure which may be helpful to any disorganized carpenter who has a mixed pile of bolts and nuts and wants to nd the corresponding pairs of bolts and nuts. The procedure uses our (and the carpenter's) ability to construct e ciently highly expanding graphs. The problem considered is given a collection of n bolts of distinct widths and n nuts such that there is a 1-1 corresponden...

Purpose. The research purpose is to study the effectiveness of artificial maintenance mined-out space based on use cable bolts reduce dilution coefficient when mining low-thickness ore bodies. Methods. Geotechnical mapping rock mass according Q, RMR, RQD and GSI rating classifications conducted, as well a linear survey fracture system in hanging wall footwall rocks performed using compass GEO I...

With growth the construction technologies, Cold-Formed Steel, CFS, sections are widely used in ordinary steel buildings because of some advantages such as light weight, ease of installation, decrease in cost, and increase in speed of operation. Using the bolted connections for CFS joist is one of the best details for steel structures. The main objective of this study is to conduct an experiment...

Rock bolts have been widely used as rock reinforcing members in underground coal mine roadways and tunnels. Failures of rock bolts occur as a result of overloading, corrosion, seismic burst and bad grouting, leading to catastrophic economic and personnel losses. Monitoring the health condition of the rock bolts plays an important role in ensuring the safe operation of underground mines. This wo...