The Applied Study On The Fractal Forecasting Method Of Karst Geology

On the basic of large engineering practice, according to the complex karst geology problem of karst tunnel construction, the author grasped the major and difficult problem to research. The following main aspects are researched in the paper:1st, the macro-law and fractal character of karst development and distribution;2nd, the micro-law and fractal character of karst development and distribution;3rd, the forecasting model research of karst fractal-geology in advance of the excavation face;4th, the preliminary research of mechanical characteristic and classification of karst rock mass.From the test and research, the main achievements attained are as following:1).The macro-law of karst development and distribution: it mainly expressed on two aspects, that is, regional distribution and vertical section development. First, karst development and distribution are mainly controlled by factors on regional plane, such as, rock character, geologic structure, dynamic condition of groundwater, and climatic condition, etc. Among these factors, the three necessary factors are rock character, geologic structure and dynamic condition of groundwater. According to the regularity of mineral solution and deposition, it is suggested that mineral saturation index such as calcite, magnesium and gypsum be added to karst vertical section zoning, on the basic research of karst vertical section three-zone and the hydro-chemical kinetics theory, the quantitative degree is increased to karst vertical zoning. For the calculation problem of karst water quantity and pressure, a geo-hydro-chemical kinetics model of karst water is established. By using general water chemical component data and available basic geology data, it can be realized to forecast subsection water quantity in karst tunnel.