Study On Seepage Law Of Chenkeng Tailing Dam

The seepage action of water or the burial depth of the infiltration line is too shallow,which is one of the main factors that cause tailings dam accidents.Taking the Chenkeng upstream iron tailings dam of the Makeng Iron Mine in Fujian as the research object,field drilling sampling and indoor conventional seepage tests,consolidation seepage tests and particle grading tests were carried out.Based on the actual situation of the Chen tailings reservoir and the corresponding code requirements combined with engineering examples and based on the SEEP/W finite element seepage analysis platform,a numerical model of the Chenkeng tailings dam seepage was established and calculated and analyzed.The following research results were obtained:1)According to the test results,the iron tailings sand was divided into three types according to different particle size content((1)powder content is less than 40%;(2)powder content is greater than 40%;clay content is less than 15%;(3)clay content is 15%?30%),the three most representative calculation formulas of the permeability coefficients(Terzaghi formula,Hazen formula and Kozeny formula)were used to calculate the permeability coefficient of the iron tailings sand.The results were different from the test results.The calculation formula of permeability coefficient considering the structure and compressibility of iron tailings sand was obtained.2)The Chenkeng tailings dam seepage numerical model was conducted with two types of dam slope drainage conditions(with and without drainage pipes),three dam heights(60m,105 m,205m),and three dry beach lengths(100m,300 m,600m),three kinds of initial dam permeability coefficients(30m/h,3m/h,3 ? 10-7m/h)in a total of 54 kinds of conditions under steady state numerical simulation.3)The drainage system of the Chenkeng tailings dam can play a good role in drainage and reducing the infiltration line.If the drainage channel of the initial dam is blocked by fine particles and the drainage capacity is reduced,the infiltration line of the Chenkeng tailings reservoir may overflow from the dam slope due to the insufficient drainage capacity of the drainage pipe of the initial dam and the dam slope.Endanger the stability of the tailings dam.4)Under the condition of no dam slope seepage when the total dam height is 60 m and 105 m,the normal initial dam seepage can control the infiltration lines under the three dry beach lengths at lower positions.With a total dam height of 205 m and no dam slope seepage,the infiltration point height at the length of the dry beach at 300 m is more than 3/4 of the initial dam height of the dam,which is detrimental to the stability of the tailings dam.The infiltration line at the length of 100 m at the dry beach Seepage from the middle of the tailings dam.When there is seepage from the dam slope,the infiltration line cannot be reduced below the initial dam.5)During the operation of the tailings pond,it should be strictly managed to control the tailings grading and discharge the ore uniformly to avoid the fine particles in the tailings dam from migrating in the reservoir and blocking the initial dam,causing the infiltration line to overflow from the slope of the dam and affect the stability of tailings dam;in order to avoid the rise of the height of the tailings dam and the increased catchment area of tailings pond due to insufficient drainage capacity of the initial dam and dam slope drainage pipe,considering to use larger diameter drainage pipes or more complete drainage systems during dam construction.Figure 49;Table 15;Reference 81...