Research on the Control Technology of Floor Heave in Shallow-Buried Weakly Cemented Layered Floor Mining Roadway

To solve the serious problem of floor heave in weakly cemented layered floor, taking the auxiliary transportation roadway of the Talahao coal mine working face as the engineering background,by combining field investigations, numerical simulations, and industrial experiments, it explores the stability of layered floors and their control strategies. The research reveals that under engineering disturbances, the layered floor sequentially forms a strong disturbance zone, a weak disturbance zone, and a non-disturbed zone from shallow to deep. The deformation of the rock mass in the strong disturbance zone is the primary cause of severe floor heave, while the weak disturbance zone plays a regulatory role in deformation. The non-disturbed zone serves as the main load-bearing area. Making the coordinated bearing capacity of these “three zones” is the key to control. The layer thickness significantly influences the stability of the layered floor. Increasing the thickness from 0.2 m to 0.5 m markedly enhances floor integrity and load-bearing capacity, reduces the extent of the strong disturbance zone, and decreases the maximum floor deformation from 631.5 mm to 253.2 mm, leading to a notable improvement in floor heave conditions. Based on the joint control technology of surrounding rock, a support system comprising “high-strength roof and rib support + full-section shotcrete sealing + floor bolting and grouting” is proposed. Numerical simulations and engineering practice demonstrate that this system can form a coordinated roof-rib-floor bearing structure, effectively suppressing large-scale floor deformation.