Study on Bearing Characteristics of Internalbackfill Rectangular Open Ore Pillar
To investigate the impact of high-strength backfill materials on the bearing characteristics of rectangular open pillars during partial backfill replacement,this study conducted tests on the bearing characteristics of ore pillar samples with varying opening widths subjected to uniaxial load using a Zhongji electronic universal testing machine and a DS5 acoustic emission signal acquisition system.Additionally,a fast camera was employed to monitor and record the entire failure process.The bearing characteristics and failure mechanism of rectangular open pillars filled with high strength backfill material were summarized.The experimental results indicate that the deformation and failure stages of OPB and OPFB models can be divided into four stages:pore compaction stage,elastic deformation stage,yield stage,and post-peak failure stage,corresponded synchronously with the evolution characteristics of AE ringing counts.The b value curves for OPB model samples exhibited a slow decrease while the b value curve for OPFB model samples showed a gentle trend.High-strength backfill materials effectively mitigated strain softening in brittle materials and had significant effect on increasing residual strength after failure.Compressive strength and elastic modulus decreased as the width of filling increased in both OPB and OPFB model samples.Failure modes shifted to shear failures in OPB model samples,transitioning from ductile to brittle failures;Whereas ductile failures were observed in OPFB model samples.This research provides scientific evidence for recovery and stabilization strategies for ore pillars.
NETL
NSTL
万方数据
维普
