| Currently, the soft-rock tunnel is a familiar and complicated problem in building a new coal mine, success of its supporting or not decides the safety and normal of mine. If want obtain the successful supporting of this kind tunnel, choosing besides logical section, the scientific and logical supporting form and supporting parameter is important to get the successful supporting. So it is very important and meaningful to study proper supporting technique in deep-seated soft-rock tunnel.This article makes use of the method that associates with theoretical analysis, numerical simulation and local testing, study the supporting form of bolt and grouting which can play a great bring support bearing capacity and surrounding self-bearing capacity, and deeply studied the mechanism of damage and reinforcing by bolt and grouting. Fist, basing on theory and practice, the rule of layout crevice in surrounding and the rule of seepage rate in surrounding rock which generated by stress changing during excavation are analyzed. According to the grouting amount statistic data, generalized cement paste propagation rule, further studies on cement paste propagation characteristic and the relationship with the rock permeability.This article studies and analysis the deformation character and mechanical property, the action of cement paste in bolt and grouting and the reasons of bad anchorage of bolts in supporting the soft rock chamber are analyzed, including the mechanism of injected-bolts reinforcing surrounding, point to the exist problem and developing direction of bolt and grouting. This paper used the finite-difference program FLAC3D to simulate supporting methods in the pump room, via comparing a few of the supporting effect on stress, deformation, plastic zone development and so on in the surrounding rock, proved the effect of anchor-grouting on keeping the surrounding rock steady.According to the elastic-plastic theory, the varying law of grouting-bolting structure in elastic-plastic zone is analyzed in this article, and analyzed calculate the stability of reinforced surrounding rock by grouting-bolt in Misses criterion, including calculating ultimate bearing capacity of grouting-bolting structure, its numerical value far high to the least resistance needed to keep the stability of surrounding rock in rock chamber. In the end of this paper, few factors of impacting the stability of surrounding in soft rock and the start point to study the proper measure are expatiated and summarized. |
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