Research On The Top Coal Caving And Drawing Characteristics Of Caving Roof Coal Mining For Shallawly Buries And Hard-Thick Coal Seam

In 1980's, our country has made the person get prompt development on full-mechanized caving in the basis exploiting a technology's. Readjust oneself to a certain extent after putting into practice, improving and perfecting with rise, putting together at present for more than 20 years full-mechanized caving becomes our country exploiting the leading factor mining method thick and favoring a coal seam specially. Readjust oneself to a certain extent the high-effect exploiting need to realize top-coal caving minging, first and necessary condition being to be equivalent to coal in needing to have fine caving and drawing characteristics, Only when fine top coal caving and drawing characteristics, ability is that the parameter choosing the top-coal caving minging support, designing support structure and ascertaining proper readjusting oneself to a certain extent rationally establish the solid basis. It can be seen that carrying out the top coal caving and drawing characteristics is necessary, has important learning significance and the value studying. The main body of a book is surveyed mainly by the scene, prospecting, sampling, coal and rock Experiments in Solid Mechanics, laboratory physics similar material simulation experiment and finite element ANSYS analysis etc, and have carried out investigation and discussion and have studied opposite the top coal caving and drawing characteristics with Neimenggu Nalingou coal mine 6-2 coal seam, the main part works and conclusions are drawn as follows:1. Pass theoretical analysis and can study: Nalingou coal mine 6-2 coal seam is belonged to be similar to top coal IV, is hard coal seam, and hide the depth is more shallow, no proper direct adopt put in the top-coal caving mining.2. By laboratory physics similarity material, the analogue test can study: Nalingou coal mine 6-2~# coal seam is belonged to be similar to top coal V. Passing calculation, average supporting pressure is 28Mpa in front of the working face. Owe pressure the structure being not enough to crush top coal and then destroying top coal, and the hanging top appear on top coal, Caving angle is small, they lead to the top coal unable to timely inbreak, even caving, shaft coal resources also very difficult to ensure that coefficient of recovery.3. Through finite element ANSYS analysis can study: Top coal have beard supporting pressure is 29.9Mpa in front of working face. Degree not reaching the crushing coal seam in front of the working face. That later stage is equivalent to the coal caving is to collapse under pulling strain and the self-respect effect falls, but is not that the plasticity the queen is crushed in the front by pressure strain flows, and the hanging top also appear on top coal, Caving angle is small, no proper direct adopt put in the top-coal caving mining, too.In a word, Throughing the study of the assignment, opposite top coal caving and drawing characteristics for shallowly buries and hard-thick coal seam having made investigation and discussion going a step further, and store condition combining with Nalingou coal mine 6-2~# coal seam tax reach: This coal mine no proper direct adopt put in the top-coal caving mining under present condition without attenuated processing for top coal, otherwise coal resources very difficult to ensure that coefficient of recovery, and may cause the bigger coal resources losses.