| Open-cast coal mine of north of Huolinhe has been through many years mining,leaving a large mount of end slope coal,it's very difficult to mine the end slope compressed coal with other coal mining method,in order to avoid the loss of these raw coal,increasing the recycling rate of coal resources,using end slope coal mining machine to recycle these part of coal.End slope coal mining's crafts 1s simple,it doesn't need peeling and infrastructure alone,its mam form is using end slope coal mining machine to dig chamber in the end slope coal seam,to rob the end slope compressed in this way,leaving separate coal pillar between chambers.Separate coal pillar needs to stay stability in the time of end slope coal mining machine completing one time robbing,in order to avoid end slope coal mining machine covered,to assure end slope coal mining machine work safety.Aiming at 21#coal seam,obtaining the geological data situation and coal sample specimen of 21#coal seam by searching in the field.Spending a lot of time and work in measuring coal rock physical mechanics parameter in lab,using theory analysis and FLAC3D to set the separate pillar width.Taking into account the rheological properties of lignite,making a lot of lignite shear creep test in lab.Test device uses self-developed leveraged gravity loading soft rock shear creep testing machine,it can do the test the same as coal in the field,it overcomes that soft rock can not be easily made into standard test-piece,making the physical and mechanical properties similar to the coal in the field.Using numerical software MATLAB least square method to fit the creep constitutive equation,comparing with the indoor experimental data,getting a very good result.Obtaining separate pillar engineering target time strength by stabilizing stage the creep law,determining lignite numerical simulation mechanical parameters,selecting a safe and economical reasonable separate coal pillar width. |
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