Numerical Simulation And Application Of Polymer Grouting

Polymer grouting technology is a new chemical grouting technology that is different from traditional cement grouting.This technology has outstanding advantages and is widely used in building rectification,foundation compensation,road emptying,airport pavement repair,and seepage control.Filling leakage and many other areas.At present,the research on polymer grouting in China mainly focuses on the performance parameters of the material.However,there is still a lack of in-depth research on such issues as the grouting model,working mechanism,grouting volume prediction,and grouting uplifting of the ground.For this reason,the numerical simulation of the grouting of polyurethane polymer material and the grouting construction process were carried out.The main conclusions are as follows:Firstly,A polymer grouting penetration diffusion model was established.The grouting diffusion of polyurethane in rock and soil is regarded as a two-phase flow process under porous media.The definition of various physical properties of polymer and the porosity,average particle size,inertial resistance and viscous resistance under porous media are defined.The VOF model was used to track the two-phase flow interface between the air phase and the polyurethane slurry.Based on the Mohr-Coulomb criterion,the ultimate expansion pressure corresponding to the splitting of soil is deduced from the law of composite foundation and the theory of circular hole expansion.The reaction is exhausted by one reactant or the expansion force is reduced below the soil splitting pressure.End of the sign.Secondly,Sensitivity analysis was carried out on the influencing factors of grouting diffusion range.According to the numerical calculation results,the influence of the average particle size of the injected media is the largest among the influencing factors of the grouting diffusion range,followed by the grouting pressure,the impact of porosity is relatively small,but significantly larger than the pore size and grouting depth of the injection hole..Therefore,it is necessary to pay attention to the soil type or gradation composition before grouting.When the injected medium is dense and fine particles,high pressure grouting is required.At this time,the osmotic diffusion is accompanied by a greater degree of compaction and diffusion.The error may be large.Because the influence of pore size of the grouting hole is small,when the pressure can be satisfied by adjusting the grouting pressure,the lowest value is used as far as possible to achieve the purpose of“minimally invasive”.Thirdly,Grouting process should adopt a small number of grouting methods.For grouting uplift,it is necessary to establish the basis for filling and reinforcement such as loosening of the ground layer.According to the numerical calculation results,a single grouting amount is too long and easily causes the temperature near the grouting hole to be too high,the nozzle is blocked,the slurry is accumulated,and the pore filling is insufficient.Etc.The single grouting time should be controlled at about 10s.The grouting time interval should not be too short,and the subsequent grouting pressure should be increased by 30%⁵0%from the previous value.The polymer grouting in different depth segments can form polymer shaped piles,play a role in the replacement and reinforcement,etc.,and adjust the grouting pressure or grouting amount step by step to form the desired shape of the pile,when the pressure is constant.The pile is inverted.After regression analysis,the regression equation for grouting diffusion radius R with respect to grouting pressure P,grouting diameter r,porosity n,average particle diameter d,and ultimate expansion pressure f is obtained as follows:R?28?716.23P.⁰³⁹⁴r.⁰¹⁹³n.¹²⁰⁵d.⁰⁷⁸⁶f^-.0268.The grouting volume V regression equation isV?28?2440.6P^1.175r^0.585n^4.654d^2.356.Based on the calculation results of the diffusion range,the lifting effect of polymer grouting was studied based on the stochastic medium theory and the circular hole expansion theory.The prediction of surface displacement lift is realized under different grouting volumes.Comparing the results of field shallow grouting reinforcement uplift test,the numerical results of grouting volume and diffusion range are within acceptable limits and can be effectively used for on-site grouting construction guidance.Finally,through the consolidation and solid engineering of cement concrete pavement in a highway service area,the grouting amount,diffusion range,and lift volume were measured.The test results show that the theoretical model and calculation method established in this paper are effective,and the calculation results can be used by relevant units.Reference use.