Research On Simulation Test Of Vacuum Grouting Under Silty Sand Stratum

With the rapid economic development and the increasing scale of the infrastructure,grouting technology which is an effective way in the ground improvement,is widely used in many areas such as civil engineering,transportation,water,mining,etc.The research on grouting theory falls behind the engineering practice generally,while the permeation grouting theory that developed based on groundwater flow mechanics is the most comprehensive,and it has a wide range of applications.However,in practical engineering,using ordinary pressure and other traditional grouting method is difficult to achieve effective perfusion or unable to realize the design of diffusion radius in many grouting strata containing fine sand or silt,which has poor permeability because of the small pore.Based on this situation,the experimental study of the vacuum grouting technique has a particularly important significance.Through the indoor model experiment,this paper studied the propagation law of vacuum negative pressure in the silty sand soil and the diffusion regularity of slurry in silty sand soil body and visualization experiment of the vacuum grouting.Some understanding and achievement of this paper include:1 Based on the nature of silty sand soil and the characteristics of the vacuum experiment,this paper designs the new indoor simulation experiment model2 Through the vacuum propagation experiment,this paper concluded the propagation law of the vacuum degree in silty sand soil along the direction of one dimensional and the vacuum transmission law of which cross the vacuum well and parallel to the longitudinal walls of linear symmetric distribution points3 Through the vacuum grouting experiment,this paper summarizes the diffusion regularity of the acid sodium silicate grout in silty sand soil,under different vacuum degree,and compared it with the theoretical value of the classic osmotic grouting regression formula,analyze the difference.4 Through the visual vacuum grouting experiment,observe and record the diffusion process and form of the dyeing polyacrylamide slurry in the silty sand soil.Do some analysis and sum up the dispersion characteristics of the different viscosity of chemical grout in silty sand soil,under different vacuum degree.