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To prevent and mitigate safety risks in the mining goaf and achieve risk prevention and shifting the control frontier forward, a novel goaf stability risk early warning model is developed based on D-RES and asymmetric fuzzy association cloud. Taking into consideration the intrinsic characteristics of the goaf, an indicator system covering 12 indicators from three aspects, namely goaf morphology, rock mass physical-mechanical parameters, and goaf development status, is constructed to assess goaf stability. To address the vagueness and randomness issues in the classification criteria for goaf stability early warning, a fuzzy interval-based model is proposed to quantify warning indicators and determine their fuzzy interval range and optimal boundary information. The RES theory is introduced to analyze the interaction relationships among warning indicators, and the D numbers theory is utilized to comprehensively synthesize opinions from multiple experts, establishing a D-RES coupled weight calculation model for collaborative decision-making. Additionally, the asymmetric fuzzy association cloud is introduced to represent the uncertainties and vagueness among different risk levels, considering the finite interval and asymmetric distribution features of warning indicator levels. By integrating the D-RES-derived coupled weights, early warning of goaf stability is achieved. The validation on mining goafs demonstrates that the warning results of the model are consistent with the actual safety conditions, indicating the high applicability and accuracy of the proposed early warning model. The developed model provides a theoretical foundation for formulating safety management policies relevant to mining goafs. • The ambiguity and randomness in the grading standard have been resolved. • A coupled weight model for multi-decision group collaborative empowerment has been proposed. • An early warning model based on the Asymmetric Fuzzy Connection Cloud has been constructed. [ABSTRACT FROM AUTHOR]

Acoustic emission and digital image correlation were used to study the spatiotemporal evolution characteristics of crack extension of soft and hard composite laminated rock masses (SHCLRM) containing double fissures under uniaxial compression. The effects of different rock combination methods and prefabricated fissures with different orientations on mechanical properties and crack coalescence patterns were analyzed. The characteristics of the acoustic emission source location distribution, and frequency changes of the crack evolution process were also investigated. The test results show that the damage mode of SHCLRM is related to the combination mode of rock layers and the orientation of fractures. Hard layers predominantly produce tensile cracks; soft layers produce shear cracks. The first crack always sprouts at the tip or middle of prefabricated fractures in hard layers. The acoustic emission signal of SHCLRM with double fractures has clear stage characteristics, and the state of crack development can be inferred from this signal to provide early warning for rock fracture instability. This study can provide a reference for the assessment of the fracture development status between adjacent roadways in SHCLRM in underground mines, as well as in roadway layout and support.