Excavation Disturbance Effect And Control Technology In Deep Soft Rock Roadway Group

With the increase of the mining depth, there are many roadways excavated in the limited mining area, and those roadways form a large of roadway group. The adjacent existing roadway will be disturbed when the roadway is excavated. the disturbance effect is obviously increased under the combined action of horizontal ground stress and ground pressure in soft rock roadway, which causes that surrounding rock of existing roadway is seriously deformed and broken. So it is of great significance to study the deformation mechanism and control technology under excavation disturbance in deep soft rock roadway group. According to the engineering conditions of Zhujixi mine in Huainan, Anhui province, combined with the basic mechanical experiment, theoretical analysis, numerical simulation and engineering practice, the main research results of this paper are embodied in the following five aspects.(1)Based on the rock mechanics experiments in laboratory, the tests of surrounding rock loose zone and the stress measurement in roadway, the geological occurrence characteristics of soft rock roadway group are expounded. Based on the monitoring of mine pressure, the deformation failure characteristics of roadway are analyzed under the disturbance effect of adjacent roadway excavation. Based on plane strain and elastic-plastic stress analysis of strain softening for surrounding rock, the deformation failure mechanism in high-stress soft roadway is deeply revealed. Rheological behavior of high stress soft rock roadway is analyzed based on Burgers creep model.(2)The numerical calculation model with double roadway is established by using FLAC3 D. many factors are considered such as depth of roadway, lateral pressure coefficient, distance of roadway layout, cross-section shapes of roadway and time. By using the single factor analysis method, the influence factors of deep roadway excavation disturbance are analyzed from the aspects of stress field, displacement field and plastic zone distribution of surrounding rock. And some meaningful conclusions are given.(3)Based on FLAC3 D, a large number of numerical simulation analysis is carried out for the stability of deep roadway group from the layout of roadway group, construction sequence, and extra excavation footage. Simulation analysis is carried out for the layout of roadway group such as the same level of roadway group, inclined horizontal roadway group and the wrong level roadway group, and the most reasonable arrangement mode of roadway group staggered level is obtained.(4)On the basis of that, the arrangement of different excavation sequence is analyzed, and the law of stress field and displacement field for surrounding rock under different excavation sequence are obtained. Finally, a double-roadway model is established. The different excavation footage is simulated for the head-on distance between the first roadway and the after one. The shortest over excavation footage is obtained on the basis of maintaining the stability of surrounding rock.(5)Taking the track roadway of west wing 11# in Zhujixi coal mine as an engineering example, the research on support measures under the disturbance of adjacent roadway excavation is carried out, and the optimization scheme is deter mined. The effectiveness of the scheme is verified by the data analysis of the field monitoring.