College of Energy Engineering,Xi'an University of Science and Technology
Key Laboratory of Western Mine Exploitation and Hazard Prevention,Ministry of Education,Xi'an University of Science and Technology
School of Energy Science and Engineering,Henan Polytechnic University

“充填膏体-垮落矸石”复合充填开采是降低充填成本和提高充填采矿效率的有效手段之一,以试验矿井为工程背景,开展复合承载结构的力学特性研究。研究结果表明:复合承载结构可以采用粒径级配指数为0.4的级配矸石粒径进行模拟;膏体配比为8%水泥、15%粉煤灰、40%河砂、1.2%早强剂时强度最佳;不同膏体配比的复合承载结构,在受载过程中的应力-位移曲线趋势基本相同,可以划分为7个阶段;膏体配比与第1次失稳应力临界值成正相关,与第2,3次失稳临界值成负相关;在高应力条件下,复合承载结构呈现大变形特征,应力指数呈上升趋势,其应力-位移曲线可划分为4个阶段,仅呈现1次明显的应力峰值,第2次失稳破坏临界值与加载速率成正相关;随着应力加载速率的增加,复合承载结构临界值应力增大、位移减小。

Composite filling mining with filling paste and caving gangue is an effective way to reduce filling costs and improve filling mining efficiency. Based on the engineering background of the test mine,the mechanical properties of the composite bearing structure of the "filling paste-caving gangue" are studied. The results show that the composite bearing structure of "filling paste-caving gangue" can be simulated by the graded gangue particles with particle size gradation index 0.4. The optimal ratio of the paste for strength is 8% cement,15% fly ash,40% river sand and 1.2% early strength dose. The displacement-stress curves of composite bearing structures with different paste ratios are basically the same during the loading process. The curve can be divided into seven stages. The paste ratio is positively correlated with the critical value of the initial instability stress and negatively correlated with the criticalvalue of the second instability and the third instability. Under the high-stress conditions,the composite filling shows large deformation characteristics,and the stress index shows an increasing trend. The stress-displacement curves can be divided into four stages,but only shows one obvious stress peak. The critical value of the second instability is positively correlated with the loading rate. With the increase in loading rate,the critical stress of the composite bearing structure increases,while the displacement of the critical value decreases.

国家自然科学基金资助项目(51974226,52174127);陕西省重点研发计划资助项目(2023-YBGY-318);陕西省高校青年创新团队资助项目