Effect exerted by the direction of the resultant vector of horizontal stresses in coal and rock mass on the stability of temporary roadways

Abstract

It is important to take into account horizontal stresses when planning and designing temporary roadways. The studies show that correlated orientation of the resultant vectors of horizontal stresses and the temporary roadways is often the determinative factor for the roadway stability. It is required to identify direction of the resultant horizontal stress vector in order to correctly orient development roadways in extraction panels. Aimed to validate the optimized arrangement of temporary roadways in extraction panels, the field research is implemented in Chertinskaya-Koksovaya, Yubileinaya and Raspadskaya. Spotlight is on expedient layout of temporary roadways in extraction panels so that the roadways keep stable. It is found that the stability of the roadways depends on the location angle of a roadway relative to the direction of the resultant vector of horizontal stresses in rock mass. The stability of temporary roadways is essentially influenced by the effective horizontal stresses in rock mass. At a mining depth of 450–500 m, the maximal horizontal to vertical stress ratio reaches 2 and higher. The research proves that the stability of horizontal temporary roadways is greatly improved when they are arranged along the resultant vector of horizontal stresses. One of the reasons of temporary roadway layout in mining gently dipping coal seams without regard to the influence of horizontal stresses is the lack of approaches to the expedient layout of temporary roadways in extraction panels. The essentiality of expedient arrangement of temporary roadways in extraction panels with regard to the direction of the resultant vector of horizontal stresses is confirmed by the implemented research into stability of roadways in coal mines.