Application Of Polymer Grouting Technology In The Treatment Of Floor Heave Disease Of Highway Tunnel

Highway tunnels are an important part of road transportation,with advantages such as overcoming terrain or elevation obstacles and shortening distances.However,during long-term operation,road tunnels passing through poor geological segments often suffer from diseases such as bottom drumming,road surface damage,and lining cracking.Currently,grouting is a common method for treating bottom drumming diseases in highway tunnels.This method has low cost and can quickly restore traffic,but the treatment effect is easily affected by geological environment and grouting material performance.In order to further achieve efficient and economical treatment of road tunnel road surface bottom drumming diseases,this article studied a new type of high polymer grouting material and its grouting process.Field application research was carried out based on in-service highway tunnels in Chongqing,and comparative analysis was conducted with conventional high polymer materials through experiments,resulting in the following conclusions:(1)The mixture ratio and technical requirements of new polymer grouting materials are determined.The new polymer material composed of 1:1 polyether material and polyphenyl polymethylene polyisocyanate has the advantages of improving the bearing capacity,good filling performance,adjus Tab.le setting time and strong chemical corrosion resistance.(2)The diffusion pattern of the new polymer grouting material is influenced by the width of the fissure and the grouting volume: when the fissure width is the same,the larger the grouting volume,the greater the diffusion distance.During grouting,the pressure is highest near the grouting hole,and the pressure will generally decrease gradually along the direction of slurry diffusion.(3)The new polymer grouting material has better filling performance than the conventional polymer grouting material and can achieve efficient filling of the pavement concrete and bedrock debonded areas.(4)According to the bending and settling value monitoring,the conventional polymer grouting material and the new polymer grouting material can effectively fill the empty area,improve the noncompacting property,and improve the pavement bearing capacity and uniformity.The conventional polymer grouting material reduces the average bending and settling value of the pavement in the test section by 19 microns,while the new polymer grouting material reduces the average bending and settling value of the pavement in the test section by 42 microns,which is 1.2 times more than the conventional polymer grouting material.(5)Through long-term monitoring analysis,during the early stage of monitoring,the settlement deformation of each monitoring point had certain deformation fluctuation,within ±4mm;during the late stage of monitoring,the displacement of each monitoring point tended to stabilise,the final cumulative maximum vertical displacement of settlement of test section 2 was 28% lower than that of test section 1,the final average cumulative settlement of each section of test section 2 was 22% lower than that of test section 1;the cumulative maximum horizontal displacement of both sides of the side wall of test section 2 was 9.5% lower than that of test section 1.The cumulative maximum horizontal displacements on both sides of the side walls in Test Section 2 were 9.5% lower than those in Test Section 1,indicating that the treatment effect of the new polymer grouting material was better than that of the conventional polymer grouting material.