Scholarly record

USING OF CONICAL GAUGES PROBE FOR MEASUREMENT OF STRESS CHANGES INDUCED BY PROGRESS OF LONG WALL

L. Stas, K. Soucek, J. Knejzlik

Abstract

A new device for stress tensor measurement is developing on base relief overcoring method applied on conical shaped borehole bottom. Developing of equipment has progressed to two parallel types: for measurement of total rock stress tensor by overcoring procedure and for monitoring of induced changes of rock stress tensor impressed with uderground human activity (progress of long wall face,\ldots). This second type of device has been used to long term monitoring of the stress – strain changes. A functionality of this device was verified both in the laboratory conditions and in the conditions of Carboniferous rock mass. The induced changes of stress state of rock mass impacted by progress of long-wall were investigated. This experiment demonstrated that monitored strain changes on borehole bottom are formed both by geomechanical situation based on a progress of long-wall and perhaps by local geomechanical situation based on stress redistribution after boring of measuring borehole and on plastic deformation of creeping rock material. Relatively high time consumption to stabilization of this deformation process after drilling measuring borehole and installation of the probes is shown. In this paper the first experience of “in-situ” measurement by this equipment during of long wall extraction is described.

Publication details

Back to publication list