Stability analysis of surrounding rock by large section open shield excavation near coal seam under goaf
The shield tunneling method is becoming a new mode for the coal mine roadways excavation due to its significant advantages such as high efficiency and cost-effectiveness.Roadways in complex geological conditions in goaf areas bring many uncertainties to the stability of surrounding rock and supporting control.Taking the North Ⅱ Ventilation Roadway of Guqiao Mine as the research project,this study investigates the deformation characteristics of large cross-section open-type shield tunneling near the coal seam under goaf using field monitoring and numerical simulation method.The research results show that the displacement of rock layers and stress in surrounding rock show a trend of rapid increase followed by a slow increase,stabilizing around 35 days.The monitoring shows that the dis-placement of surrounding rock gradually decreases with the increasing depth from the roadway surface.The maximum rock layer displacement reaches 5.9 cm at 4 m above the roof,and the maxi-mum tension in anchor rods(cables)reaches 50 MPa.Comparatively,the stability of surrounding rock at the monitoring chainage 1 250 m is better than at 1 450 m.The stability of surrounding rock in roadways near the coal seam under goaf is influenced by geological conditions,excavation speed,sup-port structure,and other factors.The presented support scheme maintains the deformation of sur-rounding rock and tension in anchor rods(cables)at a relatively low level,ensuring good stability of surrounding rock.The surrounding rock and support system can withstand the load of surrounding rock,providing a safety reserve space.This study provides reference and guidance for achieving rapid excavation of shield method under deep goaf and stability control of roadways.
goafshield tunnelingstability of surrounding rockfield monitoringnumerical analysis
万方数据
维普
