Fracturing Grouting Mechanism And Experiment Study In Low-Permeability Soil

Underground Engineer in urban area was often constrained by environment, which it may cause a great influences to! These influences include the stratum settlement and the discharge of underground water. The technology of fracturing grouting is an effective method to prevent the underground water discharge to the tunnel or excavation meanwhile it is also used to control the settlement during the procedure of excavation. however, there is no enough attention payed to the mechanism theory of fracturing grouting in low-permeability soil. On the base of the fracturing grouting experiment for the engineer of highway to airport in Xiamen city, do the research studies on the theory of fracturing mechanism, the flowing of concrete grout , the uplift of stratum and the simulation method of fracturing grout prediction. The studies involve : 1, On the base of TRESCA criterion of soil elastic- plastic mechanism ,the mechanicmodel of soil fractured by the expanding cylindrical grout vacuole is built. Thefracturing press can be computed from the model. Then the second grout fracturingpressure can be induced on the mechanic theory of cooperation of the two phase——soil and grouting concrete. 2, On the base of Navi-Stokes equation of Poiseuille flow, the theory of grouting fluidrheology and the theory of varying viscosity of the grouting fluid , build the computingmodel of the largest radius covered by grouting fluid! The computing result from themodel is in according with the data of the experiment. 3, The uplift model of stratum is given on the theory of 'largest radius' and circulartruncated cone. 4, A simple computing method for grouting result prediction is given on the function ofthe grouting fabric in soil! 5, The choosing criterion of grouting material is given on the theory of grouting mechanic.The mechanic model and uplift model is also proved by the data of the groutingexperiment!...