Udc 622. 235 Study of the propagation of the shock-air wave front in the axial air cavity of a borehole charge

UDC 622.235

STUDY OF THE PROPAGATION OF THE SHOCK-AIR WAVE FRONT IN THE AXIAL AIR CAVITY OF A BOREHOLE CHARGE

Sh.A. Ochilov , Associate Professor, Department of Mining, PhD , Assoc.
D.R. Makhmudov, Associate Professor, Department of Geotechnology of Coal and Seam Deposits, PhD , Assoc.
A.N. Karamanov , doctoral student of the department "Mining"
C.M. Raimkulova , doctoral student of the Mining Department
N.Zh. Gulmurodov , master student of the Mining department


Tashkent State Technical University named after Islam Karimov, Tashkent, Uzbekistan


Аbstract: In the article studies of the propagation of the shock-air wave front in the axial air cavity of a borehole charge depending on the detonation velocity, charge mass and cavity cross-sectional area are given. The regularities obtained are characterized by dependences of hyperbolic and linear type. It has been established that the excess pressure at the front of the shock-air wave in the axial air cavity decreases with an increase in the cross-sectional area of the borehole charge cavity and distance, and increases with an increase in the mass of the explosive charge. As a result of the action of the products of the detonation wave, a kind of gas piston is formed in the gap between the charge and the axial air cavity, which, according to the laws of gas dynamics, is a pressure jump propagating at supersonic speed.

Keywords: shock-air wave, borehole charge, explosive, overpressure, air cavity, specific consumption of explosives.

INTRODUCTION. The main directions of the economic development of the Republic of Uzbekistan provide for the rise of the country's economy, mainly due to the acceleration of scientific and technological progress and the widespread introduction of energy-saving technologies. The search for effective ways to reduce the energy intensity of rock destruction is one of the main directions of modern scientific research in mining science.
In fulfilling this task, a special place is given to the mining industry. The leading role in the overall technological complex of mining processes is occupied by blasting of the theory of destruction and deformation of rocks by explosion was made by scientists V.E. Aleksandrov , E.G. Baranov , V.A. Borovikov , K.E. Vinitsky , O.E. Vlasov , A.A. P. Demidyuk , M.F. Drukovannyy , E.I. Efremov , N.F. Kusov , B.N. Kutuzov , F.I. _ Marchenko , N.V. Melnikov , E.O. Mindeli , P.S. Mironov , G.I. Pokrovsky , V.V. _ _ , V.N. Sytenkov , V.P. Tarasenko , N.U. Turuta , A.N. Khanukaev , E.I. also the influence of mining and technological characteristics on the efficiency of blasting.
On the basis of theoretical and experimental studies of N. Vanderberg , A.I.Golbinder , L.V.Dubnov , N.A.Deremin , V.P.Martynenko , V.F.Tyshevich , L.D.Khotin , A.R. Chernenko and other scientists studied the regime of detonation waves in blasthole and borehole explosive charges with an axial air cavity. Under the influence of the initial pulse, an elongated explosive charge with an axial air cavity is detonated, forming detonation waves.
As a result of the action of the products of the detonation wave, a kind of gas piston is formed in the gap between the charge and the axial air cavity, which, according to the laws of gas dynamics, is a pressure jump propagating at supersonic speed. In this paper, a design was developed for the formation of a downhole explosive charge with an axial air cavity made of a polyvinyl chloride (PVC) pipe, which provides an increase in the efficiency of blasting by increasing the duration of the blast wave pulse and reducing the specific consumption of explosives.