Influence of backfilling rate on the stability of the backfilling body- immediate roof cooperative bearing structure

To reduce the cost of backfilling coal mining and utilize the underground space of coal mines, a new back-filling mining method with low backfilling rate called constructional backfilling coal mining (CBCM) is proposed. The backfilling body-immediate roof cooperative bearing structure of CBCM is analyzed by establishing the model of the medium thick plate on an elastic foundation. The influence of the backfilling rate on the stability of overlying strata is analyzed by the numerical simulation experiment. The control effect of CBCM is verified by a physic similar simulation test. The economic benefit of CBCM is analyzed. The conclusions are: the deformation characteristics of the immediate roof and critical backfilling spacing in CBCM can be analyzed based on the Hu Haichang's theory. Exerting the bearing capacity of the imme-diate roof is beneficial to the stability of the overlying strata. The CBCM has a good control effect on the overburden in Xinyang Mine when the backfilling rate is lower than 25%. The backfilling cost of per ton coal is 37.39 yuan/t when the backfilling rate is 13.7%, with a decrease rate of 56.63% than the full-filling. The research results can provide theoretical support for the application of CBCM in coal mining.(c) 2022 Published by Elsevier B.V. on behalf of China University of Mining & Technology. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This article proposes a low backfilling rate constructional backfilling coal mining (CBCM) method to reduce the cost of backfilling coal mining. Through modeling and numerical simulation experiments, the stability and control effect of CBCM are analyzed. The research results demonstrate that CBCM has significant economic benefits in reducing backfilling costs.