Study On Slurry Diffusion Characteristics Of Sleeve Valve Tube Grouting Method

Sleeve valve tube grouting has a deep grouting depth,which can be grouted at multiple points,quantitatively and evenly in the reinforced stratum,and has low requirements on the grouting operation surface.It is used in foundation reinforcement,water-proof curtain,control of building settlement and other projects In particular,it is widely used in subway engineering construction.For the geological environment with high groundwater head and high permeability of the soil layer,the sleeve valve tube grouting method can effectively alleviate the problem of easily broken piles compared with other construction methods.The use of fast-setting slurry materials has its unique advantages.In order to better study the slurry diffusion characteristics of the sleeve valve tube grouting method,this paper uses a sand layer with better permeability as the simulated soil,and through research and optimization of the ratio of grout and sheath materials,the Sleeve valve tube grouting method plays a greater advantage in soil reinforcement.The influencing factors of sleeve valve tube grouting effect mainly consider two factors,the basic performance test analysis of slurry and casing material.Among them,the basic performance of the slurry is affected by factors such as the water-cement ratio of the slurry and the concentration of water glass.The greater the concentration of water glass,the more Ca·Si O₂produced by the reaction,and its strength increases;A large amount of Ca·Si O₂ makes the slurry lose its fluidity.As the water-cement ratio increases,more free water acts as a lubricant.Through analysis and test results,the water-cement ratio is in the range of 0.9?1.1,and the volume ratio of cement water glass When it is 1:07,the slurry performance is better.The consolidation mechanism of the shell material is the coordination of the network structure formed by the consolidation of bentonite and the cement hydration cement.The factors affecting the performance of the shell material are the water-cement ratio and the amount of bentonite.By analyzing the test results,the shell is obtained The water-cement ratio of the shell material is in the range of 2?2.3,and the addition ratio of bentonite is in the range of 1?1.5.The stability of the shell material is better.Finally,the microscopic mechanism of the grouting material and the soil consolidation body is analyzed by electron microscope scanning,which is divided into chemical mechanism and physical mechanism.,And then wrap the soil particles to form cemented soil particles for reinforcement.By simulating the grouting reinforcement test of the sleeve valve tube,studied and analyzed the relationship between slurry diffusion and injection pressure and water cement ratio.In this paper,the uniform design test method was used to formulate the grouting test plan,and the diffusion characteristics of the slurry were analyzed by the test effect:slurry Under the action of pressure,the splitting effect predominates and combines with the permeation effect.It coexists in various forms to fill the injected soil layer,and its permeable flow part is well cemented with the injected soil layer;within the injected soil layer,the slurry within the diffusion radius Mainly in the form of veins.Using the data measured by the regression analysis design test,the nonlinear relationship between the diffusion radius of the grouting slurry during the grouting process,the grouting pressure and the slurry water-cement ratio is obtained:R=0.2523P^0.2958w^0.0547.On the basis of experimental research,the sleeve valve tube grouting method was used to reinforce the shield end in the actual project,the engineering site geological conditions were analyzed,reasonable grouting parameters were adopted,and the grouting scheme was designed.Through reinforcement drilling in the later stage and analysis of the geological conditions with high water head in the formation and good permeability of the soil layer,sleeve valve tube grouting is very effective in strengthening the end of the subway,which effectively curbed the problem of water inrush at the end.