Study On Parameter Optimization Of 2 ~ # Dump In An Open - Pit Iron Mine

Paper an iron 2# mine project design, adopting the research method of the slope and detailed study of the rationality of the design of 2# mine, through study on soil mechanics parameter, mechanical shear strength of soil is better, think 2# pile next dumping performance also has a large space, in the row of soil mechanics parameters measurement is put forward on the basis of 2# design parameters and the maximum heap emissions next dumping scheme and run for 2# mine safety and economic effect to improve to provide technical support and theoretical support. Through the site Hansen formula to calculate the ultimate bearing capacity of basement can be seen that mine foundation bearing capacity is uneven, mine the foundation ultimate bearing capacity is poor, mine must clean up the weak stratum. Through the site of soft rock foundation pile load stability numerical simulation research think choose reasonable bearing stratum is a priority for the 2# mine design. Clear base after the pile of displacement design scheme has a certain practical significance, put forward a clear base after the optimal soil parameters and displacement process. The feasibility of this plan still need to do a lot more comprehensive and detailed research work, such as load-bearing performance test of mine base, rows of natural soil is rest Angle measuring and determination of soil shear strength and displacement process influence on the stability and so on, therefore, the pile of displacement design scheme is only a row of soil parameters optimization theory.In this article, through the literature research form the comprehensive understanding of mine slope stability, some iron ore 2# mine stability factors influence the field investigation and indoor test and research; optimize the site 2# in the original design, the pile of displacement design scheme is put forward. Study the following research results and conclusions:(1) Through investigation, analysis of factors influencing the stability of 2# mine, reorganize its influence factors are summarized, lay the foundation for stability study. By average formation parameters, the weakest layer and equivalent safety coefficient calculation parameters using Hansen site the formula to calculate the ultimate bearing capacity of the basement, found mine basal ultimate bearing capacity is poor, must be removed before the weak soil strata. Adopt the safety coefficient inversion of shear strength parameters than the weakest layer increases, the change of cohesive force of the inversion method of calculated results is smaller than change the Angle of internal friction calculation results, the importance of Angle of internal friction in the calculation of visible than the cohesive force is high, its influence degree is higher, the accuracy of the internal friction Angle should be paid great attention to engineering practice.(2) Through field test and laboratory test in combination with the physical and mechanical properties of soil medium, provide the basis for stability calculation parameter selection. By sieving method and the direct measuring method of determination of soil particle size composition, due to the displacement steps below 40 m, soil particle size differentiation is not obvious, use of waste rock medium size instead of mine particle size. Mining waste rock blasting heap of repose of the asymmetry of wide grading is a good material, mine earth material for mixed soil float (eggs). In accordance with the "regulations of highway geotechnical test gauge" (JTG F41-2005) by using irrigation field to determine the density of earth material. USES the trial pit water injection method for the determination of the coefficient of permeability of dump, the drying method determination of indoor soil moisture content. In accordance with the geotechnical test procedures (SD128-87) and In YZW50 microcomputer control electric stress type direct shear apparatus on the die shear method is used to determine soil shear strength parameters. Experiment results show that the equivalent substitution method of material shear strength properties is better than that of the similar grading method.(3) Based on 2-2’section of the base to simulate the research object, using ANSYS10.0 to complete the modeling process, import the FLAC3D to study soil evolution process of stress and strain. Simulation vertical stress is layered distribution inside the earth, as the soil accumulation appears at the bottom of the mine stress concentration, the basal shear strength low, and basal forming shear fracture snap out of a row of soil slope. Zero displacement of slope surface gradually expand to the deep, with the increase of pile load from the arc shape gradually to bent, and workers can be data survey landslide types in the region as a mansard, to determine the actual type of landslide to mansard.(4) Site in calculating the limit tier, the non-ferrous metal mine mine design code (GB50421-2007) 1981 su shi formula recommended by dumping height should be conservative. By Hansen formula and static water pressure formula combining site calculation of limit tier and su shi formula contrast, the former calculation result is not stable. Calculation of limit tall should base the actual contact formation parameters, take easy to cut the bad location or basal parameter calculation of limit tall theoretically reasonable.(5) According to experimental measured soil shear strength parameters of 2# site design parameter optimization, the mine finally 12° slope Angle increase, produce 530000m3 after the net amount of soil. Analysis to discuss the feasibility of the optimization scheme thinks that the pile displacement design is simply the soil parameter optimization theory, the feasible optimization scheme is still need a lot of the experimental study, and the feasibility of optimization, the parameter selection of rock and soil mechanics is the key factor. Paper put forward the order of the state parameter optimization; optimization of simple linear model is set up.