Title: Mechanical behaviour and failure characteristics of cemented paste backfill under lateral unloading condition

Authors: Hongjian Lu; Peng Liang

Addresses: School of Mining Engineering, North China University of Science and Technology, Tangshan, Hebei 063210, China ' School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing, Beijing 100083, China

Abstract: A key issue associated with mine backfill design is the determination of mechanical behaviour and failure characteristics of the cemented paste backfill (CPB), especially for CBP under lateral unloading conditions caused by excavation of adjacent stopes. In this research, a series of lateral unloading tests with RFPA3D were conducted to investigate the relationships among the cement-tailings ratio (1:4 and 1:8), lateral unloading stress (0 MPa, 0.2 MPa, 0.4 MPa, 0.6 MPa, 0.8 MPa and 1.0 MPa), mechanical behaviour, failure modes and acoustic emissions (AE) characteristics. Similar mechanical behaviour of all the CPB specimens was obtained. With different cement-tailings ratios and preloading stress values, the ultimate failure modes of CPB specimens show different forms. Additionally, increasing the preloading stress value caused a rising of AE counts. The results of this study can provide a significant reference for the backfill design and study of underground mining.

Keywords: cemented paste backfill; CPB; mechanical behaviour; failure characteristics; lateral unloading; numerical simulation.

DOI: 10.1504/IJMME.2020.105882

International Journal of Mining and Mineral Engineering, 2020 Vol.11 No.1, pp.66 - 83

Received: 25 Feb 2019
Accepted: 18 Aug 2019
Published online: 16 Mar 2020 *

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