公开(公告)号：US11313226B2

公开(公告)日：2022-04-26

申请号：US16603832

申请日：2019-02-22

Applicant: CHINA UNIVERSITY OF MINING AND TECHNOLOGY

Inventor： Nan Zhou ,  Jiaqi Wang ,  Jixiong Zhang ,  Kai Sun ,  Meng Li

IPC: E21F15/00 ,  E21C41/18 ,  E21D15/00 ,  E21D15/02 ,  G06Q50/02

Abstract: An internally injected replacement support room-type coal pillar recovery method is provided. During the recovery, the room-type coal pillars with an aspect ratio greater than 0.6 are divided into two parts: reserved coal pillars and pre-mined coal pillars. After the mining of the pre-mined coal pillars, a cemented filling material is injected into a goaf surrounded by the reserved coal pillars, and is stabilized to replace the coal pillars for support, and the reserved coal pillars are recovered. A mechanical model of the reserved coal pillars in a support overburden stage is established based on the Winkler beam theory, to obtain displacement and stress conditions of a roof of the reserved coal pillar in a support stage. A theoretical reserve-width of the reserved coal pillars is obtained according to a first strength theory of the roof and a criterion of ultimate strength of the reserved coal pillars.