Experimental Study on the Filling of Fluidized Solidified Soil in Tunnel Foundation Pits

Based on a field test of fluidized solidified soil filling in a tunnel excavation project, the construction process and filling effect were evaluated and analyzed. The test results show that the existing slurry preparation and mixing systems can achieve a satisfactory mixing effect, producing fluidized solidified soil with good homogeneity. The fluidized solidified soil can achieve a compact filling density. Within the tested parameter range, the strength of the fluidized solidified soil varied from 0.06 to 0.717 MPa, with a maximum dry shrinkage strain of approximately 0.41%. Under a 10% cement dosage, the empirical strength value at 24 hours reached about 0.3 MPa. This strength range can meet the requirements of various application scenarios in backfill engineering.