充填体—边界介质组合体剪切力学特性与参数分析

金属矿山 ›› 2024, Vol. 53 ›› Issue (2): 80-.

充填体—边界介质组合体剪切力学特性与参数分析

卢宏建^1,2　牟　超¹　武　捷¹

1. 华北理工大学矿业工程学院,河北唐山 063210;2. 河北省矿业开发与安全技术实验室,河北唐山 063210

出版日期:2024-02-15 发布日期:2024-04-03
基金资助:
河北省自然科学基金项目(编号:E2021209006)。

Shear Mechanical Properties and Parameter Analysis of Backfill-boundary Medium Combination

LU Hongjian^1,2 　MOU Chao¹　WU Jie¹

1. School of Mining Engineering,North China University of Science and Technology,Tangshan 063210,China; 2. Hebei Mining Development and Safety Technology Laboratory,Tangshan 063210,China

Online:2024-02-15 Published:2024-04-03

摘要/Abstract

摘要： 充填体—边界介质组合体接触面的剪切力学特性与参数是研究充填采场应力分布与充填体揭露稳定性评价的基础数据。通过室内直剪试验与RFPA3D 数值模拟试验联合手段,对3 种灰砂配比(1 ∶4、1 ∶8 和1 ∶20)、4 种接触面法向应力(50 kPa、100 kPa、150 kPa 和200 kPa)的充填体—边界介质组合体(充填体—围岩、充填体—矿体、胶结充填体—非胶结充填体)的剪切力学特性与声发射特征、黏聚力和内摩擦角参数变化规律进行了分析。结果表明: 随灰砂配比降低,充填体—围岩组合体峰值剪切强度减少,破坏模式由脆性变为延性,破坏形态由颗粒粘连、块状粘连到凸起体尖端被剪断。灰砂配比1∶4 组合体发生破坏时剪切应力垂直下降,振铃计数率突然骤增,其他阶段振铃计数率相对较小。灰砂配比1∶8 和1∶20 组合体从裂隙压密到破坏阶段,声发射振铃计数率密集,剪切过程中有明显剪胀变形;充填体—边界介质组合体接触面的峰值剪切强度随法向应力、灰砂配比降低而减少。胶结充填体—围岩接触面峰值剪切强度略小于胶结充填体—矿体强度,胶结—非胶结充填体组合体峰值强度远小于胶结充填体—矿岩组合体,接近非胶结充填体自身强度;充填体—边界介质组合体接触面的黏聚力和内摩擦角随灰砂配比降低而减少。充填体—围岩与充填体—矿体黏聚力和内摩擦角接近,胶结—非胶结充填体组合体黏聚力和内摩擦角参数远小于胶结充填体—矿岩组合体。研究结果拓展了充填体—边界介质组合体剪切力学特性获取方法,为充填采场稳定性分析提供了基础数据。

关键词: 充填采矿　充填体—边界介质组合体　非线性接触面　剪切力学特性　数值模拟

Abstract: The shear mechanical properties and parameters of the interface between backfill and boundary medium are the basic data for studying the stress distribution of backfill stope and evaluating the stability of backfill exposure. Through the combination of indoor direct shear test and RFPA3D numerical simulation test,the backfill-boundary medium combination (backfill-surrounding rock,backfill-ore body,cemented backfill-unconsolidated backfill) with three cement-sand ratios (1 ∶4, 1∶8 and 1∶20) and four contact surface normal stresses (50 kPa,100 kPa,150 kPa and 200 kPa) is studied. The results show that:with the decrease of the ratio of lime to sand,the peak shear strength of the backfill-surrounding rock combination decreases, and the failure mode changes from brittleness to ductility,and the failure mode changes from particle adhesion and block adhesion to the tip of the convex body and is cut. When the cement-sand ratio is 1∶4,the shear stress decreases vertically,and the ringing count rate suddenly increases,while the ringing count rate is relatively small at other stages. From the crack compaction stage to the failure stage,the acoustic emission ringing count rate is dense,and there is obvious dilatancy deformation in the shearing process. The peak shear strength of the interface between filling body and boundary medium decreases with the decrease of normal stress and lime-sand ratio. The peak shear strength of cemented backfill-surrounding rock interface is slightly less than that of cemented backfill-ore body,and the peak strength of cemented-non-cemented backfill combination is far less than that of ore-rock combination,which is close to the strength of non-cemented backfill itself. The cohesion and internal friction angle of the interface between the filling body and the boundary medium combination decrease with the decrease of the ra-tio of lime and sand. The cohesion and internal friction angle of backfill-surrounding rock and backfill-ore body are close,but the parameters of cohesion and internal friction angle of cemented-unconsolidated backfill are much smaller than those of cemented- ore-rock combination. The research results expand the acquisition method of shear mechanical properties of backfillboundary medium combination,and provide basic data for stability analysis of backfill stope.

Key words: backfill mining,backfill-boundary medium combination,nonlinear interface,shear mechanical properties,numerical simulation

卢宏建, 牟　超, 武　捷. 充填体—边界介质组合体剪切力学特性与参数分析[J]. 金属矿山, 2024, 53(2): 80-.

LU Hongjian, MOU Chao, WU Jie. Shear Mechanical Properties and Parameter Analysis of Backfill-boundary Medium Combination[J]. Metal Mine, 2024, 53(2): 80-.

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