FORMATION OF BROKEN ZONES AT THE FRONT OF SLOPE

Ðîñòîâöåâ Ä. Óïðàâëåíèå êðîâëåé ïðè ðàçðàáîòêå ïîëîãîïàäàþùèõ ïëàñòîâ êàìåííîãî óãëÿ. - Êèåâ: Íàó÷íî-òåõíè÷åñêîå èçäàòåëüñòâî Óêðàèíû, 1935. INTRODUCTION It is known, that at the front of a coal longwall the so-called bearing pres- sure zone called by hovering of a part of an underworked massif is spreaded. Earlier by Weber was demonstrated, that the seam changes the power on a direction of a coal winning, alternately sometimes thicking, sometimes thining, and the further from working face, the the vibration amplitude should be diminished [1]. Spackeler [2] guessed, that the stratum of an immediate roof represents the viced by one extremity girder. The torque entails some relief in the lower plane of this stratum. By consequent examinations [3] this phenomenon was not confirmed. In the scientific publications is detected, that in a selvage of a band of heightened pressure (HP) the oriented fractures will be derivated, and it is at the front of work- ing face in a plane of a seam the periodic character of development of an abutment pressure [4] is marked. At a location of mine workings in abutment pressure zones the major variability of intensity and extent of an HP [5] is scored. It was clarified simultaneously , that the HP zone in due course changes the location and is dis- placed deep into of massif, thus destroying a selvage of a seam and adjoining rocks. With the help of geophysical studies in Western Donbass in observational wells the alternation of bands of pressure at the front of longwalls by the way of heightened and undervoltages in a mining massif is obtained. On western flank of a field of mine by "The Heroes of Space" it is at the front of single longwall #1162, prepared along the strike of bench coal Ñ11, lieing on depth of 358 m, from a surface two vertical wells (744 and 745) on removal 208...

m were drilled from longwall. The well 744 is drilled in a middle of a wasting pole up to depth of 363 m. The well 745 is drilled in a pole in 14 m from a taking- out drift to depth of 635 m. In accordance with a face advance, in observational wells the complex geophysical studies by following methods were executed: side logging exploration and coal complex of methods of geophysical studies of well; a vertical seismic profiling ; ultrasonic logging and downhole the ultrasonic TV , tiltmeterie. The measurings and interpretation of geophysical materials were executed according to the existing normative documents. In total eleven cycles of examinations were conducted, from them eight - up to the approach of longwalls, three - after a underworking wells. On datas tiltmeterie is established, that there is a undulating angular varia- tion of burial of a underworking seam of soils from 1 î30` up to 15o. Specially con- International Conference