Study on the Microscopic Mechanism of Grouting in Saturated Water-Bearing Sand Stratum Based on VOF-DEM Method

During the construction of tunnels in saturated water-bearing sand stratum, water and mud inrush disasters often occur. Grouting is most convenient effective method to improve mechanical properties soil prevent groundwater seepage. The reasonableness Discrete Element Method (DEM) contact parameters verified by comparing repose angle test with that obtained simulations. grouting model stratum was established based on Volume Fluid-Discrete (VOF-DEM). Then, effects porosity pressure were discussed. results show (1) dense sands, permeation diffusion slurry dominates, whereas loose compaction zone well developed. (2) Loose has a wider propagation stress larger increase state. (3) In significantly affected gravity, along dominant path pipe wall boundary obvious. (4) range positively related pressure. (5) below 200 kPa, no occurs during process, sand, when 500 kPa process.