| At present,grouting technology is widely used in the treatment of water inrush problems in tunnels and hydraulic tunnels,as well as in the treatment of dam body and dam foundation leakage.Grouting can not only seal the cracks,but also strengthen the surrounding rock mass,so as to enhance the stability of the structure.Due to the unique invisibility of grouting construction,it is necessary to study the diffusion law and sealing mechanism of grouting in the cracks.Based on the existing research results,this paper studies the diffusion law of slurry in inclined smooth fracture and inclined rough fracture under the condition of dynamic water flow by building indoor dynamic water grouting test platform,and analyzes the factors and reasons influencing the grouting water plugging effect according to the slurry diffusion image,dynamic water flow,slurry coverage and other data obtained from the test The results are as follows:(1)Based on dynamic water flow,grouting test of smooth single crack under inclined Angle was carried out,sixteen groups of orthogonal tests with four factors and four levels were carried out,the test results show that the influence weight of grouting water plugging effect from large to small is fracture angle,flowing water velocity,grouting pressure and water cement ratio.According to the slurry diffusion images recorded by 16 groups of orthogonal experiments,the slurry diffusion patterns can be divided into three categories:similar circular diffusion to the fracture boundary,similar elliptic diffusion to the fracture boundary and similar elliptic diffusion to the fracture exit.There are three types of images drawn from water flow data measured by 16 groups of orthogonal experiments:single platform decline type,multi platform decline type and continuous decline type.(3)Based on Bingham fluid slurry,combined with statics,theoretical mechanics and geometry,the force analysis of fluid micro element is carried out,and the Bingham slurry diffusion model in inclined fracture under dynamic flow condition is established.The factors such as fracture inclination angle,grouting pressure,water flow velocity and fracture opening are considered,and the slurry diffusion equation is derived on this basis.(4)Based on the dynamic water flow,the grouting experiment of rough fracture under different inclined angles was carried out,three common Barton roughness curves(JRC=8～10,14～16,18～20)are selected to carry out four factors and three levels orthogonal test.The results show that the influence weight of grouting water blocking effect is roughness coefficient,dynamic water velocity,grouting pressure and fracture inclination.Four slurry distribution patterns are derived from experiments:①successful plugging,without water passage;②general plugging effect,without obvious water passage,but with partial cavity area;③poor plugging effect,with water passage and cavity area along both sides of fracture;④poor plugging effect,with large water passage and cavity area along both sides of fracture.The flow data obtained from 9 groups of orthogonal experiments can be divided into three types:horizontal continuous decline type,double platform decline type and sawtooth fluctuation type. |
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