In response to the challenges of surrounding-rock control in deep high-stress roadways, this study focuses on a synergistic support system of actively tensioned prestressed bolts and cables. Utilizing a combination of theoretical analysis, numerical simulation, and field testing, a coupled load-bearing mechanism and the methodology for determining appropriate pre-tension were systematically investigated. A mechanical model of the anchored composite system was established, revealing the synergistic support mechanism between actively tensioned prestressed bolts and cables. Theoretical calculation formulas for the load-bearing strength of the anchored composite system under both individual and combined support conditions were derived. By analyzing the in situ stress environment of the surrounding rock, a calculation method was derived for the threshold of constraint strength required for the anchored composite system to maintain roadway stability; this threshold is directly related to the magnitude of the primary rock stress. Based on this, a support design criterion was established, centered on the equilibrium relationship between the constraint strength threshold and the bearing strength of the anchored composite system. This criterion can be used to evaluate the feasibility of support schemes, assess the rationality of applied pre-tension, and determine the reasonable matching range for the pre-tension of bolts and cables through a bivariate function defining their respective thresholds. Finally, using the transportation roadway Working Face 4209 as an engineering case, the feasibility and reliability of the proposed theoretical model and design method were verified through numerical simulations and field tests, providing a theoretical basis and practical reference for the supportive design of high-stress roadways.

After the original support system in the auxiliary transportation roadway of the northern wing of the Zhaoxian Mine failed, the extent of damage and deformation varied significantly across different sections of the drift. A single support method could not meet the engineering requirements. Therefore, this paper conducted research on the classification of roadway damage and zoning repair. The overall damage characteristics of the roadway are described by three indicators: roadway deformation, development of rock mass fractures, and water seepage conditions. These are further refined into nine secondary indicators. In summary, a rock mass damage combination weighting evaluation model based on the FAHP–entropy weight TOPSIS method is proposed. According to this model, the degree of damage to the roadway is divided into five grades. After analyzing the damage conditions and support requirements at each grade, corresponding zoning repair plans are formulated by adjusting the parameters of bolts, cables, channel steel beams, and grouting materials. At the same time, the reliability of partition repair is verified using FLAC3D 6.0 numerical simulation software. Field monitoring results demonstrated that this approach not only met the support requirements for the roadway but also improved the utilization rate of support materials. This provides valuable guidance for the design of support systems for roadways with similar heterogeneous damage.

High-stress soft rock roadways in deep underground engineering often exhibit significant time-dependent deformation due to strong rheological behavior of surrounding rock. To investigate the deformation characteristics and support effect, a composite viscoelastic constitutive model considering anchored and unanchored rock zones is established based on the Maxwell rheological framework. The equivalent stiffness contribution of rock bolts is incorporated to characterize the interaction between support and surrounding rock. Analytical solutions of radial displacement and creep rate are derived using viscoelastic theory and Laplace transform methods. The effects of bolt spacing, bolt length, and burial depth on the rheological response are analyzed. Numerical simulations based on FLAC3D creep analysis and field monitoring data are used to verify the proposed model. Results show that decreasing bolt spacing effectively reduces long-term deformation, while bolt length has a diminishing effect beyond a critical anchorage length. Increasing burial depth significantly increases creep rate and total deformation. The numerical results agree well with theoretical predictions (R² ≈ 0.985), and field measurements show a relative error within 10%. The proposed model effectively describes the long-term deformation trend of high-stress soft rock roadways and provides a theoretical reference for support design under similar conditions.

Based on the governing equations of the electromagnetic radiation field and the theory of multi-layer media propagation, the governing equations for electromagnetic wave attenuation are derived. A stable solution to the resulting large-scale sparse linear system is obtained using Tikhonov regularization. A typical collapse column forward model is established using locally refined triangular mesh discretization. Forward and inverse modeling are conducted at three transmission frequencies: 0.3 MHz, 0.5 MHz, and 1.5 MHz. The results indicate that the 1.5 MHz frequency yields the best vertical resolution, with inversion results most closely matching the modeled anomaly location. In the field application at working face number 3308 using 1.5 MHz, the local polynomial interpolation inversion delineates an anomalous vertical extent of approximately 70 m (75–145 m), whereas the Kriging interpolation method yields a vertical extent of about 140 m (20–160 m), representing a reduction of approximately 50% in the vertical extent of the delineated anomaly. Post-mining exposure reveals the X16 collapse column, with a major axis of 53 m and a minor axis of 34 m, which is generally consistent with the detection results. This study confirms that local polynomial interpolation combined with locally refined triangular meshing effectively enhances the vertical resolution of radio wave transillumination, providing reliable technical support for the accurate delineation of concealed collapse columns.