Support of squeezing rocks in underground coal mines, case study: slope no. ۲ of Parvadeh no. ۱ mine

Tunnel squeezing is one of the major challenges in mechanized longwall coal mining and is primarily caused by stress redistribution following coal extraction. In main gate tunnels, the support system is subjected to significant loads during panel extraction and longwall advancement. The Tabas Parvadeh No. ۱ Coal Mine, which uses a mechanized longwall mining method, has experienced severe squeezing problems in its main gate tunnels at depths greater than ۴۰۰ m. In certain sections, the magnitude of deformation following coal extraction has exceeded the capacity of the existing support system, necessitating the evaluation of alternative support designs. In this study, the squeezing behavior of the main roadways of the Parvadeh No. ۱ Mine is investigated using the Hoek analytical method in conjunction with finite element modeling. Based on the results obtained, the tunnel support system has been redesigned to effectively withstand the squeezing pressures encountered at the current mining depth. It was determined that using TH۴۰ steel arches installed at a spacing of ۰.۵ meters is sufficient to endure the pressures exerted by the roof and sidewalls. However, it is essential to also reinforce the tunnel floor with an additional support system, such as a concrete slab.

کلیدواژه ها:

Squeezing ، Floor heave ، Hoek analytical method ، FEM ، Parvadeh mine