| Nowadays,the construction of tunnel and underground engineering in China is facing the severe test of "complex structure,changeable geological environment,frequent disasters".The water inrush management encountered in the construction can be called the world-class engineering problem.At the present stage,there are two defects in the grouting material in the early stage of grouting and later durability.In order to solve this problem,this paper mainly studies the main factors that affect the performance of C-S materials.By controlling the volume of the first grade fly ash,the water cement ratio of A liquid(cement paste),the volume ratio of A liquid B liquid,and the amount of sodium hydrogen phosphate two,a series of improvements have been made to the C-S double liquid grouting material.Firstly,the optimum formula of modified C-S material was selected by orthogonal experiment.Secondly,under the laboratory conditions,the properties of the modified C-S material and the ordinary grouting material were compared with the properties of the rheological properties and water resistance,and the analysis was carried out through two means of macro and micro.Finally,the grouting simulation was carried out with the solid flow coupling model.The grouting performance of modified C-S material and ordinary grouting material is analyzed,and the grouting equation that accords with modified C-S material is put forward.The main research results are as follows:(1)the A liquid(cement paste)in C-S material is considered according to the two conditions of water separation and fluidity: the greater the ratio of water to cement,the greater the water cement ratio,the worse the water evolution rate of A liquid,the worse the grouting effect;the greater the water cement ratio,the more dispersed the cement particles,the less hydration between the early cement particles and the slow hydration rate of the cement at the early stage,and the more the flow degree is,the more the flow degree is,the more flow degree is,the more fluidity is,the more fluidity is,the more fluidity is,the more fluidity the cement will be.Big.Considering the comprehensive consideration,the water cement ratio of A material(cement paste)of C-S material should be controlled between 0.7-1.3.(2)the water cement ratio of A liquid,the volume ratio between A liquid and B liquid,the amount and amount of the first grade fly ash and the amount of fly ash will affect the setting time of the C-S material,in which the setting time of the C-S material can be well controlled.Increasing the water cement ratio of A solution can improve the fluidity of C-S material.The addition of fly ash can improve the fluidity of C-S material very well.Decreasing the water cement ratio of A solution,reducing the first grade fly ash content and reducing the dosage can reduce the early water evolution rate of C-S material.(3)the formula of the modified C-S material was determined through the orthogonal experiment,and the performance of the modified C-S material,the common C-S material and the single liquid material were compared with the laboratory conditions.Through XRD,SEM and other microscopic means,the reasons for improving C-S performance better than traditional C-S materials in water corrosion resistance are emphatically analyzed.It is concluded that the modified C-S material is superior to the traditional grouting material in terms of rheological property and water corrosion resistance.(4)using the solid flow coupled stratigraphic model to simulate the grouting,it is found that the effective diffusion radius of the modified C-S material is greater than the effective diffusion radius of the traditional grouting material under the same grouting quantity,and the grouting effect is better,and the grouting formula is deduced by the rheological mechanics,and the formula is entered according to the field test.A grouting equation that can reflect the actual grouting condition is obtained by modifying the line. |
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