极硬岩条件下露天台阶深孔爆破质量改善研究

发布时间：2018-05-05 00:22

本文选题：极硬岩 + 露天台阶　；参考：《武汉工程大学》2015年硕士论文

【摘要】：本论文对极硬岩条件下露天台阶爆破参数进行研究,以江西金鼎钨钼矿为研究背景。该矿在开采过程中的问题主要有:爆破的大块率高、采场的二次破碎量大、炸药单耗高。本论文总结了近年来矿山爆破参数优化的方法和数值模拟在爆破模拟中的应用以及发展趋势;通过岩石力学试验得出矿岩的力学参数:单轴抗压强度241MPa,弹性模量62GPa,泊松比0.38,属于极坚硬矿岩;运用有限元软件ANSYS/LS-DYNA进行爆破模拟。主要有以下研究成果:(1)在岩石力学参数的研究中采用常规的三轴试验得到其力学特性,然后用H-B经验强度准则对研究的岩石力学参数进行估值,同时采用岩石的单轴抗压强度试验、点荷载强度试验以及摩尔应力圆作图法得到的结果对之前的估值进行了检验,综合分析并确定了金鼎钨钼矿高精度的岩石力学参数。根据岩石力学参数,基于经验估算,确定炸药单耗为0.65kg/m3。(2)在岩石力学试验研究中发现用H-B经验强度准则估算岩石的抗拉强度和岩石粘聚力与实际测量结果偏差较大,所以这种方法不适合来估算岩石的抗拉强度与粘聚力。(3)对孔径d=11cm,d=15cm和d=20cm进行模拟对比分析,d=20cm时爆破应力值最大,实验表明大孔径炮孔在高台阶露天爆破中有利于改善爆破效果,本论文选择d=20cm孔径。(4)对炸药单耗q=0.60kg/m3、q=0.65kg/m3、q=0.70kg/m3进行模拟对比分析,研究发现q=0.70 kg/m3时爆破应力值最大,台阶顶部和底部的岩石均可以很好的破坏,炸药单耗选择q=0.70kg/m3。(5)对炮孔密集系数m=1.2、m=1.5、m=1.8进行模拟对比分析,研究发现在m=1.5和m=1.8时爆破应力值均能将坡顶和坡底的岩石破坏,但m=1.5时产生的爆破振动危害较小,综合考虑选择m=1.5。对于这种极硬岩石的爆破,适当增加炮孔的密集系数,能够改善爆破效果。(6)模拟方案方面在选择了合适的爆破孔径和炸药单耗之后,在此基础上以炮孔密集系数为变量进行模拟,建立双排四炮孔的模型,能够同时考虑炮孔之间的相互作用,更加符合矿山爆破实际情况。(7)根据数值模拟选择的爆破参数,在江西金鼎钨钼矿96m水平进行现场爆破实践,爆破效果有了很大改善,与数值模拟相吻合,证明了数值模拟的可行性。本论文研究的这种矿岩极坚硬,而且横向变形性较大,极难爆破,本论文通过数值模拟获得合适的爆破参数,为该矿山解决实际问题,同时可以为类似矿山提供参考经验。
[Abstract]:In this paper, the open-air bench blasting parameters under extremely hard rock conditions are studied, with the background of Jinding tungsten molybdenum mine in Jiangxi Province. The main problems in the mining process of the mine are: high blasting rate, large secondary crushing in stope and high explosive unit consumption. In this paper, the methods of mine blasting parameter optimization, the application of numerical simulation in blasting simulation and the development trend are summarized. The mechanical parameters of ore rock are obtained by rock mechanics test: uniaxial compressive strength 241 MPA, elastic modulus 62 GPA, Poisson's ratio 0.38, and the finite element software ANSYS/LS-DYNA is used to simulate blasting. The main research results are as follows: (1) in the study of rock mechanical parameters, conventional triaxial tests are used to obtain their mechanical properties, and then H-B empirical strength criterion is used to estimate the rock mechanical parameters studied. At the same time, the results of uniaxial compressive strength test, point load strength test and molar stress circle mapping method are used to test the previous estimates, and the high precision rock mechanics parameters of Jinding tungsten molybdenum ore are analyzed and determined. According to the rock mechanics parameters and based on the empirical estimation, it is determined that the unit charge of explosive is 0.65 kg / m ~ (3. 2). In the rock mechanics test, it is found that the H-B empirical strength criterion is used to estimate the tensile strength and the cohesion of rock, which deviates greatly from the actual measurement results. Therefore, this method is not suitable to estimate the tensile strength and cohesion of rock. In this paper, the d=20cm pore size is chosen to simulate and compare the explosive consumption of 0.60 kg / m ~ 3Q ~ + 0.65 kg / m ~ 3 / m ~ (3) Q ~ (2 +) ~ 0.70 kg / m ~ 3. The results show that the blasting stress is the largest at 0.70 kg/m3, and the rock at the top and bottom of the steps can be destroyed well. The blasting stress values of m ~ (1.5) and m ~ (1.8) can destroy the rock at the top and bottom of the slope, but the blasting vibration damage caused by m = 1.5 is relatively small, so considering the selection of m ~ (1. 5), the blasting vibration damage is relatively small when the explosive unit consumption is 0.70 kg 路m ~ (3.5) 路m ~ (5) ~ (-5). The results show that the blasting stress can destroy the rock at the slope top and the slope bottom at m ~ (1.5) and m = 1.8, but the blasting vibration damage is relatively small when m = 1.5. For this kind of extremely hard rock blasting, if the density coefficient of the hole is increased properly, the blasting effect can be improved. (6) after selecting the appropriate blasting aperture and explosive unit consumption, the blasting effect can be improved. On the basis of this, the density coefficient of the hole is taken as the variable to simulate, and the model of the double row four holes is established, which can consider the interaction between the holes at the same time, which is more in line with the actual situation of mine blasting. The blasting parameters are selected according to the numerical simulation. The field blasting practice at 96m level in Jinding tungsten and molybdenum mine in Jiangxi Province shows that the blasting effect has been greatly improved, which coincides with the numerical simulation, which proves the feasibility of numerical simulation. The ore rock studied in this paper is very hard and has a large lateral deformation and is very difficult to blasting. In this paper, the appropriate blasting parameters are obtained by numerical simulation, which can solve the practical problems of the mine and provide reference experience for similar mines at the same time.
【学位授予单位】：武汉工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD235

【相似文献】