The Diffusion Law Of Waterborne Polyurethane Modified Materials In Different Particle Size Sand Distribution Layer

The coal resources in Northern Shaanxi,Xinjiang and Inner Mongolia are rich,but the water resources are scarce.The wind-blown sand layer and the Quaternary loose pore aquifers such as Salawusu formation are aquifers with water supply significance and important ecological value.In large-scale coal mining,the water conducting fracture zone can develop to the Quaternary aquifer or even the surface,which brings challenges to coal mining.The most complex one is the saturated aquifer sand layer,especially under different geological conditions,the particle grading of the sand layer is also different,and the effect of grouting is also changed.Based on this,this paper comprehensively uses laboratory test,theoretical analysis and other methods to carry out grouting tests of waterborne polyurethane with different particle sizes,and summarizes the diffusion law of waterborne polyurethane under different conditions.The main research results are as follows:(1)A simulation test system for grouting in saturated water bearing sand layer is established,and the basic performance of the water-based polyurethane slurry is tested,and the relationship between the optimal use of retarder and time is obtained.According to the test principle of single variable method,nine different test schemes are designed.(2)Under the same test conditions,the single gradient sand layer and the mixed sand layer were tested by multi-stage grouting.By using the three-dimensional laser scanner,the morphological characteristics of the stone body in different stages were obtained.Through theoretical analysis,the diffusion mechanism of slurry in single gradient sand layer and mixed sand layer is obtained.At the same time,the diffusion mode of slurry in different sand layers is found.The temporal and spatial variation law of the slurry vein when the slurry diffuses in the sand layer is mastered.(3)Grouting tests were carried out in saturated water bearing sand layers with different particle gradations,and the shapes and grouting parameters of stone bodies under different schemes were obtained.The diffusion law of waterborne polyurethane in sand layers with different particle gradations is obtained through comparative analysis.This paper has 43 figures,2 tables and 81 references.