Links

Tools

Export citation

Search in Google Scholar

Analiza fraktalnih karakteristika krhotina kod ispitivanja rasprsnuća stijene pri različitim stupnjevima opterećenja ; Analysis of fractal characteristic of fragments from rock burst tests under different loading rates

Journal article published in 2016 by Bao-Zhu Tian, Shan-Jun Liu, Yan-Bo Zhang, Zhan-Le Wang
This paper is available in a repository.
This paper is available in a repository.

Full text: Download

Question mark in circle
Preprint: policy unknown
Question mark in circle
Postprint: policy unknown
Question mark in circle
Published version: policy unknown

Abstract

Prsnuće stijene je uobičajena ozbiljna geološka opasnost kod podzemnih tehničkih radova koja uvelike utječe na razvoj projekata. Mehanizam prsnuća stijene može se objasniti zakonom raspodjele komadića stijene i njihovim fraktalnim karakteristikama. Proveden je simulacijski eksperiment rasprsnuća stijene s uzorcima granita pri dvoosnom opterećenju strojnog sustava u analizi fraktalnih karakteristika krhotina rasprsnule stijene. Krhotine granita su sakupljene i metodom selekcije podijeljene u grube, srednje, fine i mikro zrnca. Broj i raspodjela mase krhotina po veličini u različite nizove također su analizirani. Izračunate su fraktalne dimenzije krhotina stijene metodom distribucije mase-zrnatosti. Rezultati pokazuju da je stupanj opterećenja proporcionalan stupnju štete nastale prskanjem stijene; masa ostataka stijene povećava se porastom stupnja opterećenja, što pokazuje da visoki stupanj opterećenja dovodi do znatnog oštećenja stijene. Visoki stupanj opterećenja također rezultira malim količinama finih i srednjih zrna i velikim iznosom grubih zrna, uz zanemarivu promjenu mikro zrna. U uvjetima visokog stupnja opterećenja, fraktalne dimenzije ostataka stijene su male, ali je oslobođena energija rasprsnuća stijene velika. Zaključci dobiveni ovim istraživanjem potvrđuju mogućnost smanjenja rizika rasprsnuća stijene podešavanjem brzine iskapanja kod tehničkih radova i osnova su za daljnja istraživanja mehanizma rasprsnuća stijene. ; Rock burst is a common serious geological hazard in underground engineering, which seriously affects the progress of projects. The mechanism of rock burst can be explained by the distribution law of rock fragments and its fractal characteristics. A simulation experiment of rock burst was conducted with the granite samples under a biaxial loading machine system to analyze the fractal characteristics of the fragments from rock burst tests. The granite fragments were collected and divided into coarse, medium, fine, and micro grains by a screening method. The number and mass distribution of the fragments in different size ranges were also analyzed. The fractal dimensions of the rock fragments were calculated by the mass-granularity distribution method. Results show that the loading rate is proportional to the damage degree of rock burst; the mass of rock burst debris increases with the increase in loading rate, which indicates that a high loading rate leads to considerable rock damage. A high loading rate also results in small proportions of fine and medium grains and a large proportion of coarse grain, with no significant change in the micro grain. Under the high-loading-rate condition, the fractal dimensions of rock fragments are small, but the released energy of rock burst is large. The conclusions obtained in this study confirm the feasibility of reducing the risk of rock burst by adjusting the excavation rate in engineering practice and provide the basis for further study on the mechanism of rock burst.