Geological conditions of coal seams in China are very complicated. Existence of a soft interlayer in roof will greatly reduce bolt force and lower safety and reliability of the bolted structure. Regarding the relative position between locations of the soft interlayer in roof and the bolted zone

theoretical analysis and physical simulation have been combined to study the instability characteristics and deformation mechanism of the lamellate roof under mining-influence. Quantitative results of soft interlayer location inside

at the edge of

and outside the bolted zones under different stress conditions are respectively summarized especially the vertical stress

strain and roof bedding separation. To keep the roadway with a soft interlaysr in its roof stable requires not only the basic bolting but also strong supplemental support to ensure a close contact between the bolted zone and its overlying strata

eliminating bed separation and to achieve roadway stability immediately after stress redistribution. A five-grade roadway safety classification system based on the safety factor AQ is established. Then a set of classified enhanced control technologies is proposed

aiming to strengthen bearing capacity of bolts

deformed rock and self-bearing structure of the surrounding rock as a whole. Support effect has been verified by successful application to over 350 000-meter-long roadway of Huainan and Huaibei mining areas. Nationwide application is foreseeable in the near future