公开(公告)号：US20200241169A1

公开(公告)日：2020-07-30

申请号：US16756819

申请日：2019-04-18

Applicant: CHINA UNIVERSITY OF MINING AND TECHNOLOGY

Inventor： Meng Li ,  Jixiong Zhang ,  A.J.S. (Sam) Spearing ,  Zhongya Wu ,  Nan Zhou ,  Feng Gao

IPC: G01V99/00 ,  G06F30/20

Abstract: The present invention discloses a method for determining internal stress of a solid filling material, comprising the following steps: step 1) acquiring stress data of the solid filling material, and fitting the stress-strain relationship of the solid filling material; step 2) calculating surface subsidence in the solid filling area on the basis of an equivalent mining height theory with a probability integration method; step 3) calculating the expansion height of fractured zones in the area under a solid-backfill coal mining condition; step 4) calculating the strain in the solid filling material at a distance L from the rear of the stope by combing with step 2) and step 3); step 5) calculating internal stress in the solid filling material at distance L from the rear of the working face. The present invention attains the following beneficial effects: the present invention provides a method for calculating the stress in filling mass for solid-backfill coal mining. The method is simple and practical, and is of great significance for reckoning the distribution of the stress in the surrounding rock for solid backfill mining, guiding the backfill mining support design, and enriching the backfill mining pressure theory system.

公开(公告)号：US11021954B2

公开(公告)日：2021-06-01

申请号：US16763426

申请日：2019-02-22

Applicant: CHINA UNIVERSITY OF MINING AND TECHNOLOGY

Inventor： Nan Zhou ,  Hengfeng Liu ,  Meng Li ,  Zhongya Wu ,  Jixiong Zhang

IPC: E21C41/18 ,  E21F15/02 ,  E21D15/48

Abstract: A method of recovering a room-and-pillar coal pillar by using external replacement supports. In the recovery of a room-and-pillar coal pillar, a cement material wall is formed by performing pouring around a coal pillar having a width to height ratio of less than 0.6, by means of a single-pillar sack arrangement technique, such that a coal pillar resource may be mined while a wall made from a cement filling material supports an overlying stratum. After mining is complete, a coal pillar goaf region is filled with the cement filling material, and after the cement filling material solidifies and is stable, the single pillar can be recovered.

公开(公告)号：US10895154B2

公开(公告)日：2021-01-19

申请号：US16088437

申请日：2017-11-02

Applicant: China University of Mining and Technology

Inventor： Qiang Zhang ,  Jixiong Zhang ,  Zhongya Wu ,  Wenyue Qi ,  Hong Yan ,  Meng Li

IPC: E21D15/60 ,  E21D15/55 ,  E21D15/20 ,  A47B91/00

Abstract: Provided is a base mechanism of a single prop capable of being unloaded at reduced pressure, including a base bottom plate and two wedge-shaped support blocks, where one of the wedge-shaped support blocks serves as a fixed wedge-shaped support block and is welded onto the base bottom plate, and the other of the wedge-shaped support blocks serves as a movable wedge-shaped support block and is connected to the fixed wedge-shaped support block by using a screw rod and a nut. The present invention can effectively unload the single prop at reduced pressure or remove the single prop in a contracted manner, is of a simple structure, is convenient to operate, has a good use effect, overcomes the technical problem that it is difficult to unload a single prop at reduced pressure in this technical feature, and is widely applicable in this technical field.