Stress and deformation evolution characteristics of gob-side entry retained by roof cutting and pressure relief
•Mohr circle models for stress evolution of 110 mining method were established.•Stress evolution characteristics were revealed and divided into 11 states.•The essence of deformation was revealed from the perspective of stress evolution.•Corresponding suggestions were proposed for entry control in 11...
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Veröffentlicht in: | Tunnelling and underground space technology 2022-05, Vol.123, p.104419, Article 104419 |
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Sprache: | eng |
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Zusammenfassung: | •Mohr circle models for stress evolution of 110 mining method were established.•Stress evolution characteristics were revealed and divided into 11 states.•The essence of deformation was revealed from the perspective of stress evolution.•Corresponding suggestions were proposed for entry control in 110 mining method.
To control the stability of gob-side entry in 110 mining method, the evolution mechanism of surrounding rock stress and deformation in the whole life cycle of the entry must be understood firstly. The Mohr circle analysis model of stress evolution process is established in this study, and the evolution characteristics of the stress and deformation are revealed. Meanwhile, the theoretical analysis results are verified by numerical simulation and engineering data. It can be concluded that the stress and deformation evolution of the gob-side entry can be divided into 3 periods and 11 stages. In these stages, the surrounding rock before mining face is mainly characterized by small deformation, which is mainly caused by the unbalanced stress. The main control idea is to increase the minimum principal stress and reduce the maximum principal stress in the surrounding rock by using the roof cutting and high prestressed support technology, to ensure that the stress circle is far away from the envelope. After mining face excavation, the surrounding rock is mainly characterized by large deformation, which is not only affected by the changes of stress but also by the movement of the overlying roof. Therefore, the main control idea is to adopt materials with high strength and stiffness to temporarily support the entry in the process of roof movement. Although deformation cannot be completely prevented, it can ensure that the stress circle in surrounding rock does not exceed the envelope. It means that the surrounding rock is not damaged, and the surrounding rock is still safe after the roof movement stops. This paper reveals the essence of entry deformation from the perspective of stress evolution and puts forward the corresponding control measures. The achievements can provide theoretical guidance for engineering design of gob-side entry control in 110 mining method. |
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ISSN: | 0886-7798 1878-4364 |
DOI: | 10.1016/j.tust.2022.104419 |