Floor Heave Behavior and Control of Roadway Intersection in Deep Mine.pdf

1 INTRODUCTION Rocks mass of roadway in deep mine show soft be- havior because they are located in high stress envi- ronment. Due to its larger cross section and complex geometries deformation of floor around roadway in- tersection is usually greater than roadway doesn’t in- tersect. Floor heave has a great influence on ventila- tion, transportation, and so on, thus a lot of literatures already exist about this issue, but there are only a few in which was based on alternating effects between softening and creeping (Yang et al. 2006). Strata of North ventilation roadway at -990m level in Tangkou colliery is silty mud rock in mainly green and cinereous, mingled with a little fine sand rock at some locality. Protodrakonov scale of hard- ness f is 2.2, pressive strength is 19MPa, and tensile strength ranges from 1.67MPa to 4.45MPa. The bur- ial depth of roadway is nearly from 1029m to 1035m, maximum main stress is about 31.6MPa, and the vertical stress is between 25MPa and 26MPa ( Liu et al. 2005), which is larger than its pressive strength, thus softening deformation and creeping deformation will occur simultaneously (Wang et al. 1994). A case has been observed that the deforma- tion of roadway intersection was less before about the 45th day after it was formed, but then acceler- ated and convergence between roof and floor reached 565mm at the 90th day, among which floor heave accounted for more than 70 percent. There- fore, behavior and controlling technique of roadway intersection in deep mine was investigated according to conditions of a roadway intersection at -990m level in Tangkou colliery, with effects of soften- ing/creeping of rocks mass interaction being consid- ered by means of numerical simulation method. 2 NUMERICAL SIMULATIONS PROCEDURE 2.1 Failure criteria Pwipp model (a visco-plastic model combining WIPP model (the rock creep visco-elastic model) and the Drucker- Prager model) is used in this study. Total strain includes de