Experimental Study On Pulsating Gas Pre-split Grouting

Fracturing grouting reinforces the soil and improves the properties of the soil through the squeezing of the soil veins by the veins and the action of its own skeleton.However,when encountering dense formations,the grouting pressure is small,and the slurry is difficult to inject into the soil;if the grouting pressure is too large,the phenomenon of slushing will occur again.To solve this problem,the pulsating gas is used to pre-disturbance the soil,and then the new technology of grouting the pre-disturbed soil.First of all,according to the test requirements,a gas fracturing device with controllable frequency of gas pressure and gas pressure change which can be used for indoor test was designed.The pulsating gas fracturing device and the constant pressure gas fracturing were used to investigate the law of the expansion of the cracks in the soil and the change of the vertical stress of the soil,and explored the differences between the two.In addition,the article also emphatically explored the influence of gas pressure change frequency and gas pressure on pulsating gas fracturing,and summarized its laws.On the basis of summarizing the law of gas fracturing,a laboratory experiment of pre-disturbed soil fracturing grouting was carried out.After fracturing the soil with the aid of the gas fracturing device,the grouting device with independently controlled grouting pressure is used to grouting the undisturbed soil,the constant pressure gas predisturbed soil,and the pulsating gas predisturbed soil respectively.In the process,the grouting pressure,the development of slurry veins and the variation law of vertical earth pressure were explored.The superiority of grouting after pulsating gas pre-disturbed soil is verified through experiments.