METHOD OF DEVELOPMENT WORKING PROTECTION Russian patent published in 2002 - IPC

FIELD: mining industry; applicable in protection of development workings in pillarless extraction of coal seams. SUBSTANCE: method includes laying of separate blocks on one another in worked-out space, on working brow, by layers with formation of protective strip along working following the advance of breakage face provided with powered support units, and creation of stull between blocks of upper layer and seam roof by wedging with yielding member. Preliminarily determined is length of roof span between extreme unit of powered support and extreme block of upper layer of protective strip by offered mathematical expression. Protective strip is formed over length smaller that or equal to span length. For this purpose, irrespective of adopted length of span in wake of advance of breakage face and advance of powered support units on the first partial length of newly-formed span, laying of blocks is started from seam floor and so that each block of next layer is displaced relative to each preceding layer with formation of stages of ladder profile in longitudinal direction of protective strip by filling with blocks of part of remaining free space on length of preceding span. Then as units of powered support advance, process of laying of blocks on text partial length formed span is carried out in procedure similar to that on the first partial length until full filling of free space on length of preceding span and partial filling with said blocks of free space on length of newly-formed span. Cycle of laying blocks on length of next spans is continued with provision of stull between blocks of upper layer and seam roof on each partial length of newly-formed span. In this case, length of each stage is selected by experiment within 30 to 5 cm and so as to provide stability of lower layer of immediate seam roof on span length which is determined by an inequality. Actions for determination of length of each span and checking of conditions ensuring stability of exposed roof on said length of span are repeated when structure of lower layer of rocks of seam immediate roof changes. EFFECT: improved performance of working supported behind breakage face. 2 cl, 2 dwg