Modification Experiment And Applied Study On The Grouting Support Material Of Broken Surrounding Rock

The stability of tunnel surrounding rock is an important condition to ensure mine safety production,For the broken surrounding rock tunnel,grouting is an effective support method to improve the stability of them. At present, most of the grouting support technology use the pure cement as the grouting material, it exists some disadvantages,such as the poor pour-ability, short diffusion distance and large pumping resistance, so that the effect of grouting is bad, which affects the safety of the mine tunnel. To solve the above problems, this paper proposes to mix some admixture in the pure cement slurry,to improve the pour-ability by change the property of the cement slurry, it can increase the diffusion radius of the cement, enhance the effect of grouting,improve the safety in production of tunnel.This paper carries out a series of experimental studies on the cement slurry which mix admixture.(1) Study on physical-mechanical propertie of the admixture slurry.The results show that when the water cement ratio is between 0.5 and 0.6,the quantity of admixture is 5%,every property parameters of the admixture slurry is more stable than pure cement slurry.(2) Study on pour-ability of the admixture slurry. The study found that the admixture slurry can penetrate the simulative rock crack quickly and in the same grouting pressure and grouting time, the admixture slurry flow faster, the discharge is bigger than pure slurry.(3) Study on the cohesion of the admixture slurry.The study found that the admixture slurry has the same strength as that of the pure slurry and it can enhance the plasticity of the bond body, delay the broken time.Applied the above experimental study results to 1110 tunnel scene support test of No.3 nickel mine area in Jinchuan. It achieved good grouting effect,accelerated the rate that supporting structure the control the deformation of tunnel. Obviously, the admixture slurry can improve the grouting effect effectively, strengthen the supporting function of the grouting, and provide better safety guarantee for the stability of tunnel surrounding rock.