Study On The Function Law Of Influencing Factors Of Vacuum Permeation Grouting

Permeation grouting is widely used in engineering because of its small disturbance to stratum.But its low grouting pressure and insufficient slurry diffusion distance often lead to poor grouting effect.Vacuum permeation grouting provides a new technical method to solve this problem.Based on the theoretical formula of permeation grouting and the plane seepage model,this paper deduces the formula of vacuum distribution law under the condition of gas supplement,revises the boundary condition of slurry permeation diffusion,deduces the modified theoretical model of diffusion formula under vacuum negative pressure condition,and draws preliminary conclusions through programming calculation and data analysis,which verifies the correctness of the modified theoretical model.It provides an expanding idea for guiding grouting design and construction scientifically.According to the basic theory of grouting,the cement slurry with bentonite and sodium silicate as additives was selected as the test slurry,and the performance test was carried out,and the appropriate slurry formula was determined.The grout and sand used in the experiment were prepared and particle size analyzed,a test device for easy control of grouting pressure and vacuum degree was self-assembled,the vacuum degree of the device was monitored and debugged.The distribution rule of vacuum degree was predicted according to the deduced theoretical formula.The experimental results are analyzed,and the effects of soil saturation,vacuum degree and slurry viscosity on grouting results such as grouting injectability,consolidation properties and slurry diffusion mode are obtained.By comparing the measured radius with the theoretical model of vacuum correction,it is proved that the theoretical diffusion model of vacuum correction is more suitable for predicting slurry diffusion under vacuum negative pressure,the main characteristics of vacuum permeation grouting process are revealed.The results of this paper are helpful to understand the mechanism of vacuum permeation grouting,provide theoretical support for the application and development of vacuum permeation grouting,and provide reference for engineering design and construction.