Published on 01 February 2020
Quang Ninh coalfield over the years has witnessed geotechnical issues such as surface subsidence and strata caving, deformation and fracture due to the underground coal mining.
These issues have been preliminarily investigated mostly by using field observation.
The corresponding solutions and measures, however, seem to be inactive and perfunctory. This paper presents an analysis of height of strata caving, evolvement of deformation and movement zone, caving angle in strike direction, surface subsidence and strata movement when mining thick-gently inclined and/or closely distributed coal seams by using a physical model based on a case study of Khe Cham basin, Quang Ninh coalfield, Vietnam. The model shows that roof strata cave cyclically with a height being 5-6 times mining height; caving angle ranges from 64 to 67 degrees; maximum subsidence magnitude stabilises around 1.5 m; and strata behaviour caused by the mining of lower seam is less severe as that of the upper seam. The paper’s findings are useful for engineers to better plan and design technical solutions to improving safety in thick coal seam extraction.
Tags: физическое моделирование; просадка; движение; дефо
ISSN 1998-4502 (Print) ISSN 2499-975Х (Online)