Research on mining methods of thick coal seam under villages

According to the question of a huge amourt of tick coal seam unde vllages in China,layere lig mining,groutin rlig in overburden bed- separation and caving zone fractued zone and nev type of illege relocation were proposed.BEylayered fling mining .the thick calseam was dided into two lay ers or several ayers and which was mined with conventional illig nining method.Through groutin riling metod,th riling slurry could be grouted into the bed-separation under keystrata gap around gangue and crevice in the caving zone fractured zone and then th filing body was formed;whieh coud conirol overying strata activty, with the new ype ofollage relocation,the sustainable developing and moder illages to which th villages above no- mining cal seam were relocating w ere established on thestabe ground on mined- out werea, o thecalseam unde illages was ovrall.lerated. The anal sis ofthe three methds cononic profis showed that the economic profits of thee inds of mining methd all ad a growing trend with an increasing of coal seam thckness and a declining trend with a growing ofth illage's population density, And the profis for layere .ling mining had the smallest growth range or decline range wile profis fo illage relocation had the lagest. Fmally:the basc pricipes which should be followed when selecting mining methods for thick coal seam under villages were summarized.