Support failure of a high-stress soft-rock roadway in deep coal mine and the equalized yielding support technology: a case study

Abstract

There are many soft-rock roadway coal mines in China. The surrounding rocks of the high-stress soft-rock roadways in deep mine are especially difficult to be supported using the traditional supporting way. In this study, the south wing rail roadway on the second level of Yunjialing coal mine in China was used as an example to analyze the deformation and failure characteristics and influencing factors of roadway. On this basis, this study proposed the equalized yielding support idea which employs the yielding rings to realize the pressure equalization on the bolts and cables in the section. To achieve this purpose, the first bolt-mesh-cable equalizing pressure yielding support was integrated with the second grouting reinforcement. The results proved that the yield rings of the bolts and cables on the spandrel of the arched roadway firstly developed yielding deformation; then the deformation extended to the vault of the roadway; the bolts and cables achieved a yielding extreme value of 15 and 18 tonnes, respectively. The roadway surrounding rock tended to be stable at the 26th day after the maintenance. The equalizing pressure yielding supporting technology plays a moderate pressure-releasing and actively controlling role on the surrounding rocks in the soft-rock roadway with large deformation.

A statistical analysis of geomechanical data and its effect on rock mass numerical modeling: a case study

“…The variations in the measured geomechanical parameters of the rocks reveals how substantially the statistical approach can affect the state of stress and strain when the data set is input to the numerical model. Numerical methods are widely used for solving a variety of technical problems (Studeny and Scior 2009;Jing 2013;Sun et al 2015;Smith et al 2019;Li et al 2020). However, Feng and Hudson (2010) emphasized that selecting the correct methods for obtaining the data required for the selected modeling method was one of the steps of appropriate design procedures in geomechanics.…”

Influencing Factors of Disturbance Effects of Blasting and Driving of Deep Mine Roadway Groups

“…With the expansion of mine design capacity, safe mine production has become increasingly difficult using a single roadway; two, three, or even multiple roadway development and deployment methods have therefore become a necessary choice [3,4]. e increase of mining depth further introduces roadway effects, such as high ground stress, high ground temperature, high permeability pressure, and mining disturbances, and the appearance of rock pressure is particularly complicated [5][6][7]. To ensure the stability of rock surrounding roadways and production safety, systematic research on the factors that influence the blasting and excavation disturbances of adjacent roadways in deep mine roadway groups has therefore become increasingly prominent.…”

Fiber Bragg Grating Monitoring of Full-bolt Axial Force of the Bolt in the Deep Strong Mining Roadway

“…This is an active support method, and it provides timely support resistance to the surrounding rock and effectively improves the surrounding rock strength to restrain the separation and deformation of the surrounding rock [ 1 , 2 , 3 ]. Deep mining roadways face many factors such as high ground stress, high ground temperature, high osmotic pressure, and mining disturbances, which are challenging for bolt support [ 4 , 5 , 6 ]. Therefore, to increase the reliability of bolt support and roadway safety, it is becoming increasingly important to monitor the law governing the bolt’s axial force evolution by means of refinement.…”