Stability Control Mechanism of High‐Stress Roadway Surrounding Rock by Roof Fracturing and Rock Mass Filling

Abstract

Large deformation of roadway and coal bump failures have always been the focus in deep underground engineering. By considering the Lu’an mining district in China, the failure mode and stability improvement process of high-stress roadways were analysed with the field tests and numerical simulations. The field test results showed that a great amount of deformation and serious damage occurred in surrounding rocks during panel retreat due to the suspended roof. A novel approach employing roof fracturing and collapsed rock filling effect was adopted to maintain the roadway stability. A numerical model was established with the Universal Distinct Element Code (UDEC) to research the fracturing characteristics between the roadway and gob roofs and the stress change in the surrounding rock. The modelling results demonstrated that, without fracturing roof, the peak vertical stress of the coal pillar was 18.3 MPa and the peak vertical stress of the virgin coal rib was 15.6 MPa. The roadway was in a state of high stress. With fracturing roof, the peak vertical stress of coal pillar was 9.3 MPa and the peak vertical stress of virgin coal rib was 13.4 MPa. The fractured rock mass in the gob expanded in volume and provided supporting resistance to the overlying strata, which relieved stress concentrations in the coal pillar. Field measurement results indicated that the roadway large deformation was successfully resolved during excavation and panel retreat after implementing the novel approach, providing useful references for the application of this novel approach in similar coal mines.

Numerical Studies of Floor Heave Control in Deep Mining Roadways with Soft Rocks by the Rock Bolts Reinforcement Technology

“…According to statistics, the actual repair rate of roadways in Ukraine is as high as 80%. A similar repairing rate is noted by researchers from other countries [3,4]. Te instability problems that are exacerbated due to deep mining are roadway surrounding rock large deformation, foor heave, support failure, and roof fall.…”

“…Kulatilake et al used 3DEC software to simulate highstress roadways and proposed the use of 3 m bolts and inverted arch roadways to control the surrounding rock [25]. Qi et al [3], and Zhang et al [28] simulated the failure mechanism of soft rock roadway by UDEC. Sakhno et al [29] performed numerical modelling of controlling a foor heave of roadways in the soft rock by ANSYS.…”

Numerical Simulation Study on Mechanical Characteristics and Width Optimization of Narrow Coal Pillar in Gob-Side Coal Seam Tunnel

“…Bai et al [13] further established the roof destruction criteria and studied the roof bending deformation behavior model. Qi et al [14] provided a method to support the steadiness of the roadway by using the roof fracture and collapse filling effect, which successfully solved the large deformation problem of the roadway in the process of excavation and panel retreat. Moreover, Some scholars [15][16][17] established models of fracture mechanics and elastic-plastic mechanics to study the stress distribution of strip pillars and the displacement and stress distribution of small pillars in a horizontal coal seam, which provided a theoretical foundation for the NCP stability and control technology of adjoining rock.…”

Case Study on the Stability Control of Broken Surrounding Rock in Roadway Excavation on the Edge of a Collapsed Stope Area

“…At present, the problem of stability control of surrounding rock in stope mining within the scope of degraded stopes is still a hot and challenging issue [20]. e above research results laid the foundation for further research on surrounding rock control technology in stope mining within the range of mining and mining.…”