Cause and Solution to Roadway Deformation in Vietnam Underground Coal Mines

Abstract

The deformation and support method of roadways have always been important issues in safe
mining and production. Vinacomin's statistics show that, by 2021, there will be 64.19 km of roadways
that need to be repaired (accounting for 25% of the total new roadways). Thus, the problem of maintaining
roadway stability is facing difficulties in underground coal mines in Vietnam. To find out the causes of
roadway failures, a case study at roadways of the Khe Cham I and Khe Cham III coal mines, Vietnam, is
presented in this paper. Based on the results of a detailed field survey, the deformation characteristics of
roadways and the failure mode of support structures were investigated. The results show that the roadway
deformation is severe and the main support cannot control surrounding rock mass. Also, the destruction
of support structure is frequent on reused roadways, affecting production efficiency and work safety.
Therefore, to reduce deformation and increase roadway stability, a new support method called “multistage
anchor of rock bolt + cable bolt” has been developed and a new longwall mining system with critical
coal pillar width has been proposed. The new findings of the research can provide references for scientific
studies, and apply them in Vietnam's underground coal mine practices.