According to construction scheme of some weak surrounding rock large span double and multi-arch tunnel works, finite element value simulation method is adopted to research weak surrounding rock deformation characteristic, anchor bolt mechanics characteristic, preliminary support and secondary lining structure mechanical characteristics, etc, and the research result shows that: repeatedly distur...

The surrounding rock control technology of mining roadways in large inclination seams with a weak structural plane the roof is one most challenging fields underground roadway support. In view serious deformation transportation 1201 working face mine, and failure characteristics instability mechanism are analysed. self-stability mechanical model block structure under support effect established, ...

A Raman microspectroscopic study of several fulgurites has been undertaken. A fulgurite is an amorphous mineraloid, a superheated glassy solid that is formed when a lightning bolt hits a sandy or rocky ground and thermal energy is transferred. The Raman spectra revealed several forms of crystalline and fused silica and also the presence of polyaromatic hydrocarbons found in an interfacial zone ...

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...

This article presents the application of a self-excited acoustic SAS system for non-destructive testing (NDT) roof-bolt housings in laboratory and real mine conditions. The proposed with filtering mechanism was applied to J64-27 composite anchors. conducted tests allowed successful confirmation usefulness detection rod defects, damage coupling anchor rock mass stress state itself. eliminating e...

The umbrella-shaped bolt (U-bolt) is a novel type of mechanical used for rock reinforcement. It made smooth steel bar, hinges, rigid rods, and sliding blocks. During installation operation, the tension converted into extrusion force on mass deep in slope, so that higher compressive strength to obtain greater friction anchoring force. In this article, structural analysis results U-bolt provided,...

Abstract Rock stress is causing unwanted deformations of deep underground spaces. Large increase the risk failure. The excavation causes rock changes in surrounding mass, and resulting can be measured. In this paper, we present a method to monitor mass using rebar bolts instrumented with strain gauges track within bolt. Next that, describe in-situ testing heating-induced natural environment. he...