R.I. Shishkov

Kuzbass State Technical University, Kemerovo Russian Federation

 S.M. Tagiev

Kuzbass State Technical University, Kemerovo Russian Federation

A.V. Remezov

 Kuzbass State Technical University, Kemerovo Russian Federation

 

STUDY OF ROCK PRESSURE AND ITS FORMS IN THE CONDUCT CLEANING WORKS (PART II)

 

            Annotation: analysis of the factors determining the formation of the reference pressure in the zones of influence of geomechanical and advanced treatment developments.
            Keywords: geomechanics , rock pressure , voltage , roofing
 


Fig. 2. Scheme of interaction of basic and immediate roof with steep seams ( section through the fall )
            There are several classifications of the roof coal seams demolition. By easily collapses rocks are mostly of the roof , in which the power of the immediate roof easily collapses more than 7 times the capacity of the reservoir , ie híê / m> 7, It destroyed hard - who híê ≤ 1m. When híê / m> 8-10 breed close the roof completely swelling main roof . With a relatively rigid support in the goaf , she collapses , but only bends .

            Periodically freeze and caving and close the main seam roof as stope causes the wave-like nature of the reference pressure . Fig . 3 shows a diagram of the wave-like nature of the bearing pressure at the top of the formation , executed by longwall with full caving roof .



Fig. 3. Scheme of the wave-like symptoms bearing pressure front face of lava : 1 , 2 , 3, 4 - reference pressure curves in the roof ; I, II, III, IV - the position of the working face
        Under the influence of stress in part of marginal stope often there is a shift towards the formation of coal mined-out space , the development of cracks in it and its destruction . This process is commonly referred to spin the coal working face . The width of the coal extraction area depends on many geological and mining- technical factors and varies from 0.3 to 4.3 m .
            Stability breeds coal seam roof in a near space lava can be estimated coefficient Ku sustainability loose roof [ 2 ] :
                                                                 (3)

where mñë  - the power of the lower layer ( formation separately ) immediate roof ; - Tensile strength of the layer breed in compression ; Ks - the inverse of the square of the loose roof space; Êòð - fracture coefficient equal to the square root of the total number of cracks per 1 m2 of the roof.

        When Êó < 0,8  and a false roof is formed immediately upon the outcrop , with Êó = 0,8-1,1 she is in critical condition and needs fixing after coal mining , with Êó=3-5 is stable with lining , and when Êó =5-6 is stable without lining .
        Thus, analyzing the subject it can be said that the implementation of the prevention of rock pressure and its form is determined by a combination of the following factors : physical and mechanical properties of rocks ; strained state of the array ; by structural weakening , and their orientation in space of principal stresses .

 

Bibliography:

1.                 1. Artemiev, B. V. Mining mechanical / B. V. Artemyev, G. I. Korshunov, A. K. Loginov [et al.] – St. Petersburg: Nauka, 2011. – 102.

2.                 2. Egorov, P. V. Geomechanics / P. V. Egorov, G. G. Stumpf, A. A. Renev [and others]. – Kemerovo, 2002. -239 C.