Failure mechanisms and destruction characteristics of cemented coal gangue backfill under compression effect of non-uniform load

作     者：Feng, Guo-rui Guo, Wei Qi, Ting-ye Li, Zhu Cui, Jia-qing Wang, Hao-chen Cui, Ye-kai Ma, Jing-kai 冯国瑞;郭伟;戚庭野;李竹;崔家庆;王昊晨;崔业凯;马敬凯

作者机构：College of Mining Engineering Taiyuan University of Technology Taiyuan China Shanxi Province Research Center of Green Mining Engineering Technology Taiyuan China Shanxi Province Coal-based Resources Green and High-efficiency Development Engineering Center Taiyuan China Shanxi Key Laboratory of Mine Rock Strata Control and Disaster Prevention Taiyuan China 

基　　金：Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering National Natural Science Foundation of China, NSFC, (2021SX-TD001, 2021SX-TD002, 202303021211060) Natural Science Research General Program for Shanxi Provincial Basic Research Program, (U22A20169) 

出 版 物：《Journal of Central South University》 (中南大学学报（英文版）)

年 卷 期：2024年第31卷第8期

页      码：2676-2693页

摘      要：Backfill mining is one of the most important technical means for controlling strata movement and reducing surface subsidence and environmental damage during exploitation of underground coal resources. Ensuring the stability of the backfill bodies is the primary prerequisite for maintaining the safety of the backfilling working face, and the loading characteristics of backfill are closely related to the deformation and subsidence of the roof. Elastic thin plate model was used to explore the non-uniform subsidence law of the roof, and then the non-uniform distribution characteristics of backfill bodies’ load were revealed. Through a self-developed non-uniform loading device combined with acoustic emission (AE) and digital image correlation (DIC) monitoring technology, the synergistic dynamic evolution law of the bearing capacity, apparent crack, and internal fracture of cemented coal gangue backfills (CCGBs) under loads with different degrees of non-uniformity was deeply explored. The results showed that: 1) The uniaxial compressive strength (UCS) of CCGB increased and then decreased with an increase in the degree of non-uniformity of load (DNL). About 40% of DNL was the inflection point of DNL-UCS curve and when DNL exceeded 40%, the strength decreased in a cliff-like manner; 2) A positive correlation was observed between the AE ringing count and UCS during the loading process of the specimen, which was manifested by a higher AE ringing count of the high-strength specimen. 3) Shear cracks gradually increased and failure mode of specimens gradually changed from “X” type dominated by tension cracks to inverted “Y” type dominated by shear cracks with an increase in DNL, and the crack opening displacement at the peak stress decreased and then increased. The crack opening displacement at 40% of the DNL was the smallest. This was consistent with the judgment of crack size based on the AE b-value, i.e., it showed the typical characteristics of “small b-value-large crack and

主 题 词：cemented coal gangue backfill crack opening displacement degree of non-uniformity of load failure mode non-uniform load 

学科分类：081901[081901] 0819[工学-海洋工程类] 08[工学] 

核心收录：

D　O　I：10.1007/s11771-024-5713-5

馆 藏 号：203144469...