| According to the current grouting theory and its practical development, there are two main features:(1)the grouting theory falls behind its practical development;(2) the progress of grouting in rock mass lags behind that of grouting in soil mass. Aiming at the grouting of the fractured rock mass problem of theory and time with the current situation, this essay adopts the method of combining theoretical analysis, laboratory test, numerical simulation with projects of field research, which is based on a research topic about Grouting of the fractured rock mass in shiyuejing candidate beishan area for high level randioactive waste repository in gansu province and makes the following achievements:(1) Based on domestic and foreign researches of grouting of the fractured rock mass and considered the special geological and hydrological conditions in beishan, a suitable grouting material based on superfine cement is put forward by conducting optimum proportion tests.(2) A diffusion model of Binham fluids is deduced from the basic flow equation of Binham fluids, N-S motion equation and continuity equation. Considering time-dependent characteristics of its viscosity and the current typical equation of it, some flow laws of time-dependent based Binham fluids in fracture are achieved.The result indicates that the grouting pressure was changing deeply markedly along the grouting path with the changing of viscosity.The pressure decreased quickly with the increase of viscosity and the spreading radius.(3) The calculation method of fractured rock mass seepage stress coupling is put forward based on discrete element and the calculation process of seepage-stress coupling analysis in UDEC is proposed. The distribution law of grouting pressure in the process of single fractured grout diffusion mechanism is gained by numerical computation method. Through establishing a model of cross fracture network seepage of rock masses, a rule is obtained that the controllable parameters(grouting pressure, grouting time and grouting materials) and the uncontrollable parameters(ground stress, lateral pressure coefficient, joint aperture, joint dipping, joint spacing and length and joint roughness) in grouting system have impact on Binham grouting diffusion.(4) A method based on Monte-Carlo simulation is presented to build a discrete fracture network. Combined with the special geological and hydrological conditions around brohole BS05 in beishan,one discrete fracture network was achieved and a distribution map of permeability coefficient is given in this paper, then study on the numerical simulation by using UDEC software. The calculation results shows that improving the grouting pressure or prolonging the grouting time is benefit to achieve better diffusion effect. It can better optimize the parameters of grouting.A grouting design method based on DFN in fractured rock mass was primary put forward finally. |
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