The particular “rich coal, meager oil, and deficient gas” energy structure of China determines its high degree of dependence on coal resources. After over 100 years of high-intensity mining activities in Northeast China, East Region, and the Southern Region, coal mining in these areas is facing a series of serious problems, which force China’s energy exploitation map to be rewritten. New energy bases will move to the western and northern regions in the next few years. However, overlapping phenomena of multiple resources are frequently encountered. Previous exploitation mainly focused on coal mining, which destroys many mutualistic and accompanying resources, such as uranium, gas, and oil. Aiming at solving this unscientific development mode, this research presents a case study in the Ordos Basin, where uranium, coal, and gas/oil show a three-dimensional overlapping phenomenon along the vertical downward direction. The upper uranium and lower coal situation in this basin is remarkable; specifically, coal mining disturbs the overlaying aquifer, thus requiring the uranium to be leached first. The technical approach must be sufficiently reliable to avoid the leakage of radioactive elements in subsequent coal mining procedures. Hence, the unbalanced injection and extraction of uranium mining is used to completely eradicate the discharged emissions to the environment. The gas and oil are typically not extracted because of their deep occurrence strata and their overlapping phenomenon with coal seams. Use of the integrated coal and gas production method is recommended, and relevant fracturing methods to increase the gas migrating degree in the strata are also introduced. The results and recommendations in this study are applicable in some other areas with similarities.

The effects of three main factors, including polypropylene fiber content, composite cement content and curing time on the unconfined compressive strength of fiber-reinforced cemented clay were studied through a series of unconfined compressive strength tests. The experimental results show that the incorporation of fibers can increase the compressive strength and residual strength of cement-reinforced clay as well as the corresponding axial strain when the stress peak is reached compared with cement-reinforced clay. The compressive strength of fiber-reinforced cement clay decreases first, then increases with small-composite cement at curing time 14 d and 28 d. However, fiber-reinforced cement clay’s strength increases with the increase of fiber content for heavy-composite cement. The compressive strength of fiber-composite cement-reinforced marine clay increases with the increase of curing time and composite cement content. The growth rate increases with the increase of curing time. The failure mode of composite cement-reinforced clay is brittle failure, while the failure mode of fiber-reinforced cemented clay is plastic failure.

With the recovery of the wind oxidation zone in 13116 working face of Gubei Coal Mine as the engineering background, the occurrence condition of coal seam and the bedrock wind oxidation zone characteristics were analyzed. On this basis, the time‐varying rheological parameters of superfine cement slurry and the permeability characteristic parameters of roof strata in wind oxidation zone were measured; then, a grout diffusion equation was established with the parameters obtained previously for the permeability characteristics of roof strata in the wind oxidation zone of Gubei Coal Mine. The grouting design was applied in actual engineering projects and its engineering effect has been proved to be satisfactory. The results indicate that superfine cement slurry whose water‐cement ratio is 0.6 is a typical power‐law slurry consistent with time‐varying rheological parameters. It has better rheological properties during pumpable period, and its rheological parameters can be controlled by highly dispersive nano‐SiO₂ and polycarboxylate superplasticizer. For grouting in wind oxidized zone, comprehensive consideration must be given to effective permeability K_e, porosity ∅ , and time‐varying rheological parameters c₀, k, and n. To realize effective diffusion of grouting in coal and rock mass, grouting pressure and diffusion time must be reasonably designed rather than excessively increased.

China’s energy structure mainly depends on coal resources, which will still play the dominant role in economic development in the future. With the mining depth increasing, the deep roadway construction will be exposed to a complex stress environment, increasing the difficulty of roof control and further hindering the mining activities. The problem of deep roadway excavation causing significant fracture scope of surrounding rock in and outside the anchorage zone has attracted much attention. For the large crack scope existing in the roadway roof of deep underground openings, this paper focuses on the exploration of upgrading the support system. In order to solve this problem, we investigated the zone damage of the roadway roof with the discrete element model using the UDEC trigon method and damage quantified evaluation with data analysis. The long anchorage and zone linkage support technology was proposed based on the damage control effect of varying lengths of supporting bolts. The purpose of extending the length of bolts is to link the more severely damaged rock mass in the shallow part to the minimum damaged part in the deep place, aiming to form the thick anchor zone to mobilize the rock mass in each zone to participate and bear the load together. Furthermore, the onsite application of long anchorage and zone linkage technology gained good control effects in the selected typical roadway with different geological conditions. The results show obvious resistance in cross-section shrinkage, integrity maintenance, and minimization of crack scope in the roadway roof. The promotion of long anchorage zone linkage technology can help the mine with similar situations uplift the efficiency of working and guarantee the safety of miners during mine service life in the deep coal roadway.