| With the improvement of the transportation network in the western of China, the development of hydropower resources and deep exploitation of mineral resources, a large number of traffic tunnels, hydraulic tunnel and mining well projects are under building. In underground constructions under complex hydro-geological conditions, water gushing, collapse and other geological disasters are often encountered. Casualties, property lost and construction delay caused by water gushing are very severe comparing with that by other geological disasters. Therefore, the theory and technology of water gushing disaster governance through grouting method become the key scientific issues witch must be solved peremptorily. In this paper, base on the practice and solution of grouting block diffusion theory and technical problems, a kind of polymer modified cement grout material suitable for grouting in hydrodynamic conditions was developed, a single plane fracture model was established for grouting in in hydrodynamic conditions. by theoretical analysis, model experiment and numerical simulation methods, diffusion and movement laws of the new type material in hydrostatic and hydrodynamic conditions was researched, the criterion of water gushing plugging by grouting was established. Through the comparison with other traditional grouting material, such as c-s grout, influencing factors and mechanisms of grout diffusion for different grouts were analyzed systematically, there engineering application was researched too, a series of research results were obtained on this basis.(1)Based on the special needs for grouting in hydrodynamic conditions and polymer modification mechanism, the main agent and additives of the new grouting material were determined, the material composition and ratio were optimized using orthogonal test. Through a series of mechanical test were carried out to obtain performance indicators of the new material, the methods of measuring pumpability and dispersion resistance were proposed. By instrumental analytical methods, microscopic characteristics of the composite system were studied, the role of the polymer in the composite system was revealed. Based on the project, the technical characteristics and operation process of the new grouting material for water gushing governance were researched. It was confirmed that the good dynamic the new material was suitable for grouting in hydrodynamic conditions.(2)A single plane fracture model for grout diffusion was established. Through measurement of time-dependent behavior of viscosity with cement grouts, viscosity-time function was obtained. The flow pattern of grouts was analyzed systematically. By taking the time-dependent behavior of viscosity into generalized Bingham fluid constitutive equation, the grout diffusion law in hydrostatic and hydrodynamic conditions was researched. The grouting diffusion function for a single plane fracture was established.(3)To ascertain grout diffusion law and its influencing factors, a quasi-three-dimensional single plane fissure grouting model tests were carried out, revealing that cement-based quick-setting grout diffusion obeys "asymmetric elliptic (AE)" law. Transient and steady-state equation of grout diffusion traces was established. The pressure and velocity fields distribution was obtained. The three-dimensional numerical model for a single plane fissure grouting was established. By using time-dependent viscosity constitutive equation, the transient law of grout diffusion behavior, pressure field and velocity field was researched. By mutual verificationd and comparison of theoretical analysis, model tests and numerical simulation results, it was researched that how key parameters, such as underground water pressure, velocity, grouting pressure and quantity of flow, influence distribution of diffusion traces, pressure field and velocity field and its variation law.(4)The conversion law of hydrostatic head, velocity head and head loss in plugging gushing water by grouting, was researched systematically, revealing the relationship between diffusion opening and velocity of underground water. Groundwater velocity maxima existence and grouting the feasibility of complete occlusion was analyzed. Based on the research results of grout diffusion law in a single plane fissure, the criterion of water gushing plugging by grouting was established.(5)The principle of grouts selection in water gushing governance engineering was researched, the application test of the new material in situ was carried out too, confirmed that the material has its obvious advantages in water gushing governance projects, hydrological tracer test and its data analysis method witch was very useful in grouting design was proposed. The research results were applied to water gushing governance grouting in Zhangmatun iron mine and Zhongliangshan Chongqing tunnel gushing water governance, good effect was achieved. They have a broad application prospect of engineering.
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