Mechanical behaviors of deep pillar sandwiched between strong and weak layers

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68145535%3A_____%2F23%3A00571272" target="_blank" >RIV/68145535:_____/23:00571272 - isvavai.cz</a>

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S1674775522002311" target="_blank" >https://www.sciencedirect.com/science/article/pii/S1674775522002311</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jrmge.2022.11.006" target="_blank" >10.1016/j.jrmge.2022.11.006</a>

Result language

angličtina

Original language name

Mechanical behaviors of deep pillar sandwiched between strong and weak layers

Original language description

A variety of coal room and pillar mining methods have been efficiently practiced at depths of up to 500 m with least strata mechanics issues. However, for the first time, this method was trialled at depths of 850–900 m in CSM mine of Czech Republic. The rhomboid-shaped coal pillars with acute corners of 70°, surrounded with 5.2 m wide and 3.5–4.5 m high mine roadways, were used. Pillars were developed in a staggered manner with their size variation in the Panel II from 83 m × 25 m to 24 m × 20 m (corner to corner) and Panel V from 35 m × 30 m to 26 m × 16 m. Coal seam inclined at 12° was affected by the unusual slippery slickenside roof bands and sometimes in the floor levels with high vertical stress below strong and massive sandstone roof. In order to ensure safety, pillars in both the panels were continuously monitored using various geotechnical instruments measuring the induced stresses, side spalling and roof sagging. Both panels suffered high amounts of mining induced stress and pillar failure with side-spalling up to 5 m from all sides. Heavy fracturing of coal pillar sides was controlled by fully encapsulated steel bolts. Mining induced stress kept increasing with the progress of development of pillars and galleries. Instruments installed in the pillar failed to monitor actual induced stress due to fracturing of coal mass around it which created an apprehension of pillar failure up to its core due to high vertical mining induced stress. This risk was reduced by carrying out scientific studies including the three-dimensional numerical models calibrated with data from the instrumented pillar. An attempt has been made to study the behavior of coal pillars and their yielding characteristics at deeper cover based on field and simulation results.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

20701 - Environmental and geological engineering, geotechnics

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2023

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Rock Mechanics and Geotechnical Engineering

ISSN

1674-7755

e-ISSN

2589-0417

Volume of the periodical

15

Issue of the periodical within the volume

5

Country of publishing house

CN - CHINA

Number of pages

16

Pages from-to

1111-1126

UT code for WoS article

001006040900004

EID of the result in the Scopus database

2-s2.0-85147121131