SUPPORT TECHNOLOGY OF LIMESTONE ROOF ROADWAY IN QIUJI COAL MINE

The safety production pressure in coal mines is huge, and there is a general phenomenon of over-supporting in roadways.Even hard and dense thick limestone roofs do not dare to be unsupported.1102 track roadways of Qiuji Coal Mine is taken as the engineering background, by constructing a hard roof deformation analysis model, quantifying the role of

Intrauterine Knife Sharpeners device (IUD) is a well-accepted means of contraception.Although it is safe and effective, some serious complications may occur.It should be paid attention to a 45-year-old female admitted to the hospital for aggravated abdominal pain and dyspareunia for 2 months.She was found to have two IUDs in her body, one VISION FA