Numerical investigation of the mechanical behavior of the backfill—rock composite structure under triaxial compression

• Published in: International journal of minerals, metallurgy and materials Vol. 30; no. 5; pp. 802 - 812
• Main Authors: Lu, Hongjian, Wang, Yiren, Gan, Deqing, Wu, Jie, Wu, Xiaojun
• Format: Journal Article
• Language: English
• Published: Beijing University of Science and Technology Beijing 01.05.2023; Springer Nature B.V; School of Mining Engineering,North China University of Science and Technology,Tangshan 063210,China
• Subjects: Acoustic emission; Backfill; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Composite materials; Composite structures; Composites; Compressive strength; Corrosion and Coatings; Deformation; Emission analysis; Failure modes; Glass; Materials Science; Mechanical analysis; Mechanical properties; Metallic Materials; Mine tailings; Natural Materials; Numerical analysis; Plastic deformation; Residual stress; Rocks; Strain; Surfaces and Interfaces; Thin Films; Tribology; acoustic emission; backfill—rock composite structure; triaxial compression; mechanical behavior; numerical simulation; backfill–rock composite structure
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-022-2554-9

To ensure safe and economical backfill mining, the mechanical response of the backfill—rock interaction system needs to be understood. The numerical investigation of the mechanical behavior of backfill—rock composite structure (BRCS) under triaxial compression, which includes deformation, failure patterns, strength characteristics, and acoustic emission (AE) evolution, was proposed. The models used in the tests have one rough interface, two cement—iron tailings ratios (CTRs), four interface angles (IAs), and three confining pressures (CPs). Results showed that the deformation, strength characteristics, and failure patterns of BRCS under triaxial compression depend on IA, CP, and CTR. The stress—strain curves of BRCS under triaxial compression could be divided into five stages, namely, compaction, elasticity, yield, strain softening, and residual stress. The relevant AE counts have corresponding relationships with different stages. The triaxial compressive strengths of composites increase linearly with the increase of the CP. Furthermore, the CP stress strengthening effect occurs. When the IAs are 45° and 60°, the failure areas of composites appear in the interface and backfill. When the IAs are 75° and 90°, the failure areas of composites appear in the backfill, interface, and rock. Moreover, the corresponding failure modes yield the combined shear failure. The research results provide the basis for further understanding of the stability of the BRCS.