Model tests on fracture grouting reinforcement of silt embankment by using Soletanche method

Based on large-scale indoor model tests, the attenuation law of strength and stiffness of silt embankment under the action of capillary water and the reinforcement effect of the embankment by using the Soletanche method are studied. Four working conditions, newly constructed embankment, attenuated embankments affected by the capillary water with different groundwater levels (20 and 40 cm) and fracture grouting reinforced embankment, are simulated. Moisture content distribution, physical and mechanical properties of the silt embankment are detected. General stiffness, force and deformation characteristics of the embankment model are obtained under grading cyclic loading and unloading conditions. Micro-piles and fracture grouting spread forms are observed during the excavation of the embankment model. The test results indicate that the general stiffness of the silt embankment will reduce by 70% because of the capillary water, the shear strength of embankment soil will decline, and the vertical plastic deformation of the embankment increases rapidly with the increasing load. The horizontal layered fracture grouting not only blocks the rising channels of capillary water, but also forms a space frame with the bottom expansion micro-piles to bear the load with soil together, of about 50%. The reinforcement effect of the embankment by means of the Soletanche method is significant.