Experimental Study On Sodium Silicate Reinforced Sand

Poor geological conditions bring many hazards to engineering construction,so in engineering practice,it is necessary to deal with and improve the load-bearing conditions of the section where it is located.Grouting reinforcement is a commonly used method of foundation soil reinforcement in engineering,and water glass is its commonly used sand-solid grouting material.Therefore,it is necessary to carry out experiments on the sand-fixing effect of sodium silicate,continuously optimize the parameters and improve the sand-fixing effect.Based on the properties of sodium silicate,the paper analyzes and summarizes the influencing factors and characteristics of sodium silicate slurry,and analyzes and studies the physical and mechanical characteristics of sodium silicate-sand soil and its penetration and diffusion characteristics through geotechnical tests and simulation tests,and obtains the following Mainly understand the results.1.The aging,viscosity and gel time of water glass are all affected by modulus and Baume degree.Among them,the relationship between gel time and modulus and Baume degree is nonlinear.The nature of the seepage of the grout in the soil depends on its rheology;the gel time of the water glass will affect the consolidation time of the water glass grouting solid sand body,and then affect the grouting effect such as the strength of the solid sand body sample.2.The single factor test of the gel time of water glass shows that under low p H conditions,the gel time of the slurry decreases with the increase of p H,showing a non-linear relationship.When the p H is greater than 6,the change of the gel time is small;When the degree is constant,the gel time of the slurry decreases with the increase of the modulus,and the gel time-modulus curve gradually converges with the increase of the modulus;when the modulus is constant,the gel time of the slurry decreases with the increase of the Baume degree,and the gel time decreases with the increase of the Baume degree.The gel time-Baume degree curve gradually converges with the increase of Baume degree.3.The results of the consolidation test show that the consolidation time of the water glass to stabilize sand is related to the modulus and Baume degree of the water glass.Generally,the consolidation time increases with the increase of the Baume degree and the modulus of the water glass.And reduce.4.The results of the unconfined compression test found that the consolidation age has a significant impact on the strength;when the consolidation age increases from 3 days to 14 days,the strength of the sample increases from 300～1000kpa to 4000～5600kpa,and the sample is damaged From plastic deformation to brittle failure;the degree of consolidation gradually deepens from the outer layer to the inside of the sample,so the sample also shows segmental failure when it fails.5.The process and results of the direct shear test show that: ○1 Under natural conditions,the sample is first consolidated from the outside.As the age increases,the degree of consolidation of the sample increases,and the consolidation range gradually deepens to the inside.A certain structure is formed inside;this kind of consolidation method and structural characteristics of the sample make it stable when subjected to external forces;○2 The strength and consolidation age of the water glass solidified sand,and the modulus of the water glass Baume degree is related,and it is not determined by a single factor,and there is a coupling effect between various factors.6.The results of the disintegration test show that the stability of the reinforced sand in water is related to the Baume degree of sodium silicate.The greater the Baume degree of sodium silicate,the higher the disintegration rate of the reinforced sand and the worse the water stability of the solid sand body..The consolidation age and the modulus of sodium silicate have little effect on the disintegration of the solid sand body.7.The test results of the particle size analysis of the solid sand show that the content of smaller particles in the sand body after water glass reinforcement decreases,and the content of larger particles increases;the reinforced sand is compared with unreinforced sand.The sandy soil is reduced,indicating that the soil particles are more evenly distributed after reinforcement.8.Permeation and diffusion test results show that: under certain grouting pressure and grouting volume,due to the high viscosity of water glass with high Baume degree,the diffusion range of penetration grouting will increase with the increase of Baume degree of water glass.Decrease;the diffusion range of water glass in the sandy soil layer will also be affected by the modulus of the water glass.As the water glass modulus increases,the diffusion range of the grout in the sandy soil layer first decreases and then increases,at a modulus of 2.5 When reaching the lowest value.According to the SEM image,it can be seen that the water glass gel is wrapped on the surface of the soil particles,and the surface of the gel has fibrous flocculent crystals extending into the pores of the soil.