Stochastic Simulation Study Of Flow And Solute Transport In Multi-Scales Fractured Media

In the paper, based on concrete engineering, laws of flow and solute transport are researched in fractured media. Some aspects involved in model constitution, methods innovation and engineering application are discussed detailedly. Furthermore, these contents are analyzed in single fracture and network fracture scales. Simultaneously, in the course of constituting model and using methods, randomness of geological and hydro-geological features, physical parameters, is taken into account. As a result, some beneficial results are obtained.Based on the statistic characteristics of fractured geometrical elements, fracture network system is made by the Monte-Carlo method. Fracture intersection points are acted as nodes, and fractures between nodes are regarded as linear element. According to cubic law of single fracture and mass conservation principle in fracture network, the seepage mathematics model for discrete fractured network is developed in fractured rock mass. Furthermore, the calculation of the model is, also, put forward. The numerical simulation programs of groundwater movement in fractured rock mass are explored and developed by the author. The programs are involved in preprocess program Disc.for, calculation program Netw.for, and post-process program Vector.for, which can be used independently or together.According to research problems, complete couple of inhomogeneous anisotropy is made in fractured media. Compared it with traditional couple, the couple methods adequately takes randomness of fractured geometrical characteristics into account. There are two couples for different problems. One is couple of anisotropy media, that is to say, flow movement of artery fractures is described by discrete fractured network model. At the same time, it of ramification fractures and pore by equivalent continuous media model. The other is couple of inhomogeneity. It divides research region into many parts according to growth of fractures. And different mathematical models are used in different parts, which is domain decomposition algorithm.A chaos-genetic hybrid numerical algorithm of model parameters identification is putforward in fractured rock mass. It combines the advantages of chaos optimization and geneticalgorithm and expands range of search. Further, the method is of ability of jumping localoptimization. Cases show it can search the optimization values of objection function quickly.Modified stochastic walk method and emulation simulation technique are applied tomodeling solute transport in fractured network. Time step of the former is adjusted automatically, which can avoid artificial factors of defining time step, as rationality of time step has an important effect on simulation results. It is usually applied to simulation of single and planar network fracture. The latter makes full use of the laws of probability statistics, and mainly applied to simulation of planar and three dimension network fractures.At last, constituting model and using methods are applied to practical engineering, and satisfactory results are obtained.