Study About Mechanism Of Bolting-Grouting Support Based On Nonlinear Analysis

The underground terrane keeps balance state before the roadway is excavated, and once the roadway has been excavated , the stress of surrounding rocks will lose its original balance.for keeping the balance state , the stress will redistribute , and in the course of redistributing , if the intensity of rocks , the surrounding rocks will lose balance , and the roadway will be destroyed, so control steps must be taken, namely controlling of surrounding rocks. The method of control is different with the distinctness of the character of rock, the size of section , the service time , and especially the influence on roadway from earth stress.Some normal supports in our country are wooden supports , all sorts of metal bracket supports , stone or concrete space supports , bolting rods and bolting-grouting supports and so on , in other countries bolting-grouting supports , all sorts of metal bracket supports are main supports, and we call these traditional support formsWith the increase of exploitative deepness , the spread of exploitative range , unstable and terribly unstable surrounding rocks(hereinafter soft rocks for short) are more and more serious with the time , which inpact severely on the improvement of mechanization and normal production in mines . Many experts in the world study the supports of the soft rocks for a long time, and wealthy fruits have been attained.Nowadays, as a popularizing reinforcement form in soft rocks support, bolting-grouting support have some merits of construction rapid , good reinforcement effect, lower cost and so on. But at present according to the lack about theoretic fruits of bolting-grouting reinforcement and selection of support parameters only from the method of experiments and analogy, on the basis of rich analysis about the phenomena of pull and press zones, and subarea cracking in deep soft rocks, in this paper "mechanics calculational model " of original surrounding rocks in soft rocks and "nesting mechanics analysis calculational model" of bolting-grouting support body are provided , and theoretic calculation foundation is provided . In allusion to mechanics calculational model, elastic and plastic theoretic analysis of displacement is completed , and the expressions of stress and displacement of different zones about calculational model , and controlling relative expressions among radius of plastic zones and bolting-grouting zones and original anchor-hold in bolting rods have been attained. Mechanics of bolting-grouting support...