东露天矿爆破振动对采空区影响及振速预测研究

发布时间：2018-06-26 18:01

本文选题：爆破振动 + 地下采空区　；参考：《武汉理工大学》2015年硕士论文

【摘要】：因地下矿山整合,东露天矿采场工作面下方存在大量未知采空区,受露天生产爆破振动影响,采空区会出现坍塌破坏现象,引发现场生产事故。就爆破振动对地下采空区影响规律进行分析,以确定主要影响因素,建立采空区顶板振速预测公式,对合理选取爆破参数以控制爆破振动,保证地下采空区的安全稳定性具有重要实际指导意义。通过在现场进行地表振速监测,对比数值模拟预测值,证明所建立爆破振动模型的正确性,再利用LS-DYNA软件建立采空区距炮孔不同水平距离、埋深和跨度条件下的三维爆破振动模型,研究分析了爆破振动对采空区影响的传播衰减规律,并对采空区顶板振速预测模型进行了拟合。主要研究成果如下:(1)地下采空区的存在使得地表测点峰值振速有所增大,但是增幅不明显;受采空区影响爆破地震波持续时间增长,波形出现多个波峰,加强爆破振动对地表建(构)筑物的损伤破坏。(2)对比爆破振动数值模拟和地表振速实测结果,振速衰减规律及测点振速时程曲线与实际吻合,质点峰值振速平均误差为7.4%,证明所选取的本构模型、岩体材料参数及建立的爆破振动模型是正确可靠的。(3)爆破振动对采空区稳定性影响以顶板破坏为主,迎爆面侧墙次之,其中以振速水平分量对采空区破坏最为严重。随采空区离炮孔水平距离增大,顶板振速逐渐减小;迎爆面侧墙振速先增大后减小,距离20m处最大,此时迎爆面侧墙最容易破坏。随埋深增大,顶板水平向振速先稍有增大后减小,埋深35m时最大;迎爆面侧墙振速逐渐减小。随跨度增大,质点峰值振速逐渐增大,当顶板跨度大于30m后,振速增大不明显。(4)确定爆破振动对采空区影响的主要因素包括:单段最大起爆药量、采空区距炮孔水平距离、埋深和跨度,确定量纲分析基变量,运用量纲分析拟合得出受爆破振动影响的采空区顶板振速预测公式。运用得到的振速预测公式可对采空区顶板质点振速进行预测,作为受爆破振动影响地下采空区安全稳定性的判别依据;选取最大安全振速,可计算单段最大安全起爆药量,为现场爆破施工设计提供理论指导。
[Abstract]:Due to the integration of underground mines, there are a large number of unknown mined-out areas under the working face of East Open-pit Mine. Under the influence of blasting vibration in open-air production, caving and destruction will occur in the goaf, which will lead to on-site production accidents. The influence of blasting vibration on underground goaf is analyzed, the main influencing factors are determined, the prediction formula of roof vibration velocity in goaf is established, and the blasting parameters are reasonably selected to control blasting vibration. It is of practical significance to ensure the safety and stability of underground goaf. By monitoring the ground vibration velocity on the spot and comparing the predicted values of numerical simulation, it is proved that the blasting vibration model is correct, and the different horizontal distance between the goaf and the hole is established by using LS-DYNA software. Three dimensional blasting vibration model under the condition of buried depth and span is studied and the propagation attenuation law of blasting vibration on goaf is analyzed and the prediction model of roof vibration velocity in goaf is fitted. The main research results are as follows: (1) the existence of underground goaf increases the peak vibration velocity of surface survey points, but the increase is not obvious. (2) comparing the numerical simulation of blasting vibration and the measured results of surface vibration velocity, the attenuation law of vibration velocity and the time-history curve of vibration velocity at measured point are in agreement with the actual situation. The average error of peak vibration velocity of particle is 7.4, which proves that the selected constitutive model, rock mass material parameters and blasting vibration model are correct and reliable. (3) the effect of blasting vibration on the stability of goaf is mainly caused by roof failure, followed by the side wall of blasting face. The horizontal component of vibration velocity is the most serious damage to goaf. With the increase of the horizontal distance from the goaf to the hole, the vibration velocity of the roof decreases gradually, and the vibration velocity of the wall increases first and then decreases, and the maximum distance is 20m, and the wall on the side of the blasting face is the easiest to destroy. With the increase of the buried depth, the horizontal vibration velocity of the roof increases a little first and then decreases, and the maximum at the buried depth of 35 m, and the vibration velocity of the wall on the side of the explosive face decreases gradually. With the increase of span, the peak vibration velocity of particle increases gradually. When the roof span is more than 30m, the vibration velocity does not increase obviously. (4) the main factors that determine the effect of blasting vibration on goaf include: the maximum detonation charge of single section, the horizontal distance from goaf to the hole, The basic variables of dimensionality analysis are determined and the prediction formula of roof vibration velocity in goaf affected by blasting vibration is obtained by dimensionality analysis fitting. The prediction formula of vibration velocity can be used to predict the vibration velocity of roof particle in goaf, which can be used as the basis for judging the safety and stability of underground goaf affected by blasting vibration, the maximum safe vibration velocity can be selected to calculate the maximum safe detonation charge in single section. To provide theoretical guidance for site blasting construction design.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD824.2

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