Surrounding Rock Deformation Mechanisms and Control in Deep Mining: A Comprehensive Review

Deformation failure mechanism of deep high-stress fractured soft rock roadways and active-passive full-space collaborative control technology.

Controlling the stability of deep high-stress fractured soft rock roadways is a key scientific issue in mining engineering. Using the south wing return-air roadway at the - 650 level of Yangcheng Coal Mine as the engineering background, this study performed mechanical property tests, mineral composition analysis, and in-situ stress tests on the surrounding rock. It further investigated the failure mechanisms and control strategies from the perspectives of lithology and stress environment. The results indicate that the main causes of large deformation in the roadway are: high in-situ stress, high clay mineral content (> 50%) in the soft surrounding rock, superimposed mining-induced stress, and the lack of coupling between the support structure and the surrounding rock. We proposed an active-passive full-space collaborative control technology consisting of concrete-filled steel tubular supports, bolt-mesh-shotcrete, and surrounding rock grouting. Using similar simulation, we investigated the stress distribution of the surrounding rock, deformation characteristics of support structures, load-strain response of supports, and displacement evolution of the surrounding rock under coupled static-dynamic loading. The results demonstrate the excellent bearing performance of concrete-filled steel tubular supports under high static loads and strong disturbances. Field monitoring results show that the maximum roof subsidence was 51 mm, floor heave 106 mm, and side convergence 77 mm. These data indicate that the deformation and failure of the surrounding rock have been effectively controlled. This study provides a theoretical basis and technical support for surrounding rock control in deep, high-stress, fractured soft rock roadways.

Deformation and damage characteristics of surrounding rock and zonal support countermeasures for a dynamic pressure roadway in deep back-mining

Study on spatiotemporal evolution law of surrounding rock stress in deep high-stress soft rock roadways.

To address large deformation and support failure in deep, high-stress soft-rock roadways, this study investigates the - 810 m track main roadway of Pansan Coal Mine using fiber Bragg grating three-dimensional stress monitoring and borehole fracture observation, combined with FLAC3D numerical simulations. Results show that the maximum principal stress gradually transfers to the deep surrounding rock with increasing roadway distance, while the shallow rock undergoes continuous unloading, promoting plastic zone expansion and eventual instability. Timely reinforcement of the shallow surrounding rock is critical to forming an integral load-bearing system with the deep rock mass. The spatiotemporal effect of principal stress evolution is identified as the fundamental cause of roadway failure, providing theoretical and practical guidance for deep roadway support design.

Scientific basis of geomechanical monitoring and support design in deep gold mining

Deep-level underground gold mining is characterized by complex geomechanical conditions, particularly within tectonically disturbed zones where stress redistribution and rock mass heterogeneity significantly affect excavation stability. This study aims to develop scientific foundations for ground support design based on an integrated approach combining geomechanical monitoring, stress-strain analysis, and numerical modeling. The methodology includes in-situ measurements using acoustic emission monitoring, analytical evaluation of deformation behavior, and numerical simulations to assess stress distribution and support performance. The results indicate that conventional symmetric design approaches are insufficient for describing the highly heterogeneous and asymmetric deformation patterns observed in tectonically disturbed rock masses. The study identifies key features of stress concentration, zonal disintegration, and progressive failure mechanisms around underground excavations. Based on these findings, improved ground support design strategies are proposed, incorporating real geomechanical conditions and time-dependent deformation processes. The proposed approach enhances excavation stability, increases operational safety, and reduces unnecessary material consumption, contributing to more efficient and reliable deep-level mining operations.

Precise three-dimensional borehole pressure relief technology for surrounding rock control of large deformation roadways in high-stress coal seams.

To address the large deformation control problem of surrounding rock in high-stress roadways subjected to multiple disturbances, the 112 transport crosscut of Laoyingshan Coal Mine in Guizhou Province was taken as the engineering background. The deformation and failure mechanism of surrounding rock in disturbed high-stress roadways was investigated by theoretical analysis, numerical simulation, drilling cuttings testing and field monitoring. A three-dimensional precise borehole pressure-relief control technology based on the identification of the stress peak zone was proposed, and the effects of key pressure-relief parameters and engineering application were analyzed. The results show that the superposition of repeated mining in multiple coal seams, adjacent roadway excavation and concentrated coal-pillar stress causes continuous redistribution of surrounding-rock stress. The migration of peak stress toward deeper zones and the expansion of the plastic zone are the dominant factors inducing non-stationary plastic large deformation of the roadway. The proposed precise three-dimensional borehole pressure-relief technology reconstructs the stress-transfer path of the surrounding rock, transfers high stress from the shallow anchorage-controlled zone to the deeper stable zone, and preserves a load-bearing elastic structure in the shallow zone, thereby forming a coordinated control mode of "shallow load bearing and deep pressure relief". Parameter analysis indicates that borehole diameter, depth and spacing are strongly coupled. An excessively small diameter is insufficient to form an effective pressure-relief zone, whereas an excessively large diameter may damage the anchorage zone. The borehole depth should match the stress peak zone, and the spacing should ensure the continuity of the pressure-relief zone. In the field application, the stress peak zone of the 112 transport crosscut was identified by the drilling cuttings method, and a pressure-relief scheme with a borehole diameter of 133 mm, spacing of 2 m, depth of 38 m on the east side and 32 m on the west side was adopted. Field monitoring and numerical results show that the plastic zone was significantly reduced after pressure relief, and in the left rib section adjacent to the New First Mining Area haulage rise, specifically the 0-33 m section, the deformation reduction reached 82.23% after pressure relief. Borehole imaging results were consistent with the identified stress peak zone. The research results provide a reference for surrounding-rock stability control in disturbed high-stress roadways.

Study on Four-Dimensional Coupling Evaluation and Graded Dynamic Support Methods for Surrounding Rock Softening in High-Stress Soft Rock Roadways of Kilometer-Deep Mines