Parameter Control Optimization And Grouting Effect Evaluation Of Curtain Grouting Process In Jianshan Phosphate Min

With the deepening of mining depth in China,the mine water inflow will increase greatly,affecting the normal mining of mines.In the past few years,mines have generally adopted the method of dewatering and drainage in the case of large water inflow.This method will cause a series of malignant effects on the natural environment,which is not in line with the current concept of green mining in mines.Therefore,in recent years,the method of curtain grouting is proposed.Curtain grouting engineering is a hidden project.At present,curtain grouting technology is mainly based on experience and is an effective water plugging method.However,the evaluation of its effect needs to be further studied.This topic relies on the curtain grouting project of the test section of Jianshan Phosphate Mine in Kunming City,Yunnan Province.The main research contents are as follows :(1)Through the analysis of the geological and hydrological survey data of the mining area,the faults in the mining area are more complex,the length of the faults is large,and most of them show jointed cracks,which are located at the junction of the groundwater runoff area and the drainage area.The groundwater runoff flows into the mine from west to east and from south to north along the cracks.The water inflow of the mine is large,which seriously affects the subsequent normal mining of the mine.The existing drainage and drainage not only has great harm to the environment,but also can not meet the current drainage needs of the mine.In view of the above problems,after the study,the curtain grouting water plugging test section scheme was proposed,and the preliminary geophysical prospecting test was carried out in the mining area to find the abnormal position of the mining area and analyze the curtain area layout.Provide guarantee for subsequent mine water plugging.(2)Through the study of curtain grouting theory,characteristics,types,influencing factors and grouting principles,the theoretical direction and construction experience are provided for the curtain grouting project in the mining area.Based on these theories and empirical foundations,combined with the hydrogeology of the curtain area,the grouting materials and anti-seepage standards of the test section are determined.The geophysical exploration test is used to detect the water passage in the curtain area,and the curtain line is determined in the main water passage area.According to the distribution of the relative aquifuge in the stratum,the type selection and boundary of the curtain are determined.The technological process of curtain grouting is studied and developed,and the construction of the field test section is carried out through the developed grouting process.It provides a basis for parameter control optimization of curtain grouting process.(3)The parameters of curtain grouting process are controlled and optimized by means of water pressure test,borehole imaging,acoustic wave test,electromagnetic wave CT detection and borehole coring.On this basis,the effective diffusion radius of the slurry is analyzed by using the borehole permeability obtained by the water pressure test and the electromagnetic wave CT detection results.Combined with the theoretical formula,the selection and optimization results of grouting parameters such as borehole spacing and curtain thickness are obtained.Through the correlation analysis of grouting parameters by grey theory and multiple regression analysis,the regression equation of the correlation between grouting parameters is obtained.Finally,through the field test,the grouting effect under different borehole layout modes is analyzed,and the most suitable grouting hole layout mode is obtained.(4)A variety of methods are used to evaluate the grouting effect of the curtain grouting project in the test section of the mining area.Through the comparative analysis of the scene pictures before and after the curtain grouting and water plugging construction in the goaf;comparative analysis of borehole cracks before grouting and after grouting through borehole imaging;through the analysis of the variation law of grouting volume and permeability rate of each sequence hole in the west and south test sections;the water permeability rate of the inspection hole is measured by the post-injection water pressure test of the inspection hole in the test section,and the water permeability rate of each sequence hole is compared and analyzed.Through the acoustic wave test of the rock block,the degree of formation fracture development during the grouting of each sequence hole in the test section is obtained,so as to compare and analyze the grouting effect before and after the grouting of each sequence hole and between all sequences of each hole.