Research on secondary support time of soft rock roadway

In order to determine accurately secondary support time, the adjustment process of surrounding rock stress and strength in the course of supporting is analyzed based on the support principle of soft rock roadway. Based on the rheological model of soft rock roadway and the corresponding relationship between the mechanics behaviors of elastic zone, plastic zone and fractured zone and rock complete stress-strain process, the theoretical formula of secondary support time is proposed. Then the influential factors and rules of secondary support time are analyzed. To validate the study, the secondary support time theory is applied to engineering practice. Results show the roadway maintains a good stability according to the proposed secondary support time. ©, 2015, China Coal Society. All right reserved.