爆破振动对含结构面边坡稳定性影响研究

发布时间：2018-06-07 00:25

本文选题：结构面 + 爆破振动　；参考：《武汉理工大学》2015年硕士论文

【摘要】：岩体是一种不连续、各向异性的非均质结构体,其间断层、节理、裂隙和破碎带等结构面随机分布,爆破振动会对含结构面边坡稳定性产生重要的影响。钻沟石灰石露天矿边坡岩层之间存在较为明显的结构面,由于受边坡岩体结构面和频繁生产爆破等因素的影响,其稳定性已成为制约矿山安全生产的重要因素。因此,必须研究爆破振动对含结构面边坡稳定性的影响。在钻沟石灰石露天矿爆破现场进行地质调查、岩石物理力学指标试验和爆破振动试验,并对现场实测的爆破振动信号进行小波包能量分析。采用ANSYS/LS-DYNA动力有限元分析软件对矿山边坡进行爆破数值模拟,研究爆破荷载作用下含结构面边坡的动力响应,并提出了邻近边坡爆破的减振措施。本文主要研究成果如下:(1)通过现场地质调查,得到了矿山边坡结构面的分布情况,即结构面倾向为顺坡方向,与水平夹角为70°,结构面厚度为0.5m。(2)现场爆破振动试验表明,爆破地震波穿越结构面时,爆破振动速度衰减较为明显,其平均衰减率为48.59%;而地震波未穿过结构面时,其爆破振动速度并没有明显的变化。小波包分析结果表明,地震波穿越结构面时会造成爆破振动信号高频振动能量比例降低,低频振动能量比例升高。(3)数值模拟结果表明,地震波穿越结构面时,其前后质点振速幅值的平均衰减率约为50%。而通过小波包能量分析发现,50Hz左右频带的能量呈衰减趋势,而20Hz左右频带的能量呈增加趋势。对比现场试验与数值模拟的结果发现,地震波穿越结构面时爆破振动速度平均衰减率为48.59%,而数值模拟所得平均衰减率为56.29%,相对误差为9.68%。此外,数值模拟的小波包能量分析结果与现场实测的小波包能量分析结果基本一致。(4)分别考察爆源距离由20m增加到40m,炮孔孔径由160mm减小到90mm,炮孔孔数由三孔减小到单孔起爆,延期时间由25ms增加到65ms以及由无预裂爆破到有预裂爆破时,爆破振动对边坡稳定性的影响相应减小。因此,在矿山临近边坡爆破时,应采用小孔径爆破、逐孔起爆、65ms排间延时爆破及预裂爆破等减振措施,以保证边坡的稳定性。(5)采用通径系数法分析了爆破振动速度和主频两个特征参量与爆心距、总装药量、最大段装药量、高差、前排抵抗线和岩石完整性系数等爆破条件之间的关联性,得出爆心距和最大段装药量对爆破振动速度的影响较大,而对爆破振动主频影响较大的是爆心距和岩石完整性系数。(6)从能量源和爆破地震波传播过程两个方面提出了科学合理的邻近边坡爆破减振措施,并设计了一套有利于钻沟石灰石矿山生产和保证边坡稳定的生产爆破参数和预裂爆破参数。根据上述研究得到了不同爆破荷载对含结构面边坡稳定性的影响规律,提出了科学合理的邻近边坡爆破减振措施,保证了边坡的稳定性。
[Abstract]:Rock mass is a discontinuous anisotropic heterogeneous structure with random distribution of structural planes such as faults joints fractures and broken zones. Blasting vibration will have an important effect on the stability of slopes with structural planes. There are obvious structural planes between the slope strata of the limestone opencast mine in Shuangou. Due to the influence of the structural plane of the slope rock mass and the frequent production blasting, its stability has become an important factor restricting the safe production of the mine. Therefore, the effect of blasting vibration on slope stability with structural plane must be studied. Geological investigation, rock physical and mechanical index test and blasting vibration test were carried out in the blasting site of Shuangou limestone opencast mine, and wavelet packet energy analysis of the field measured blasting vibration signal was carried out. The blasting numerical simulation of mine slope is carried out by using ANSYS/LS-DYNA dynamic finite element analysis software. The dynamic response of slope with structural plane under blasting load is studied, and the vibration reduction measures of adjacent slope are put forward. The main research results of this paper are as follows: (1) through the field geological investigation, the distribution of the structural plane of the mine slope is obtained, that is, the slope direction is inclined, the angle to the horizontal plane is 70 掳, the thickness of the structure surface is 0.5 m.m-2) the results of field blasting vibration test show that, The attenuation of blasting vibration velocity is obvious when the blasting seismic wave passes through the structural surface, and the average attenuation rate is 48.59, while the blasting vibration velocity does not change obviously when the seismic wave does not cross the structural surface. The results of wavelet packet analysis show that when seismic waves cross the structural plane, the ratio of high frequency vibration energy to blasting vibration signal decreases, and the ratio of low frequency vibration energy to low frequency vibration energy increases. The average attenuation rate of the amplitude of the particle velocity is about 50. Through the analysis of wavelet packet energy, it is found that the energy of 50 Hz or so band is decreasing, while the energy of 20Hz band is increasing. The results of field test and numerical simulation show that the average attenuation rate of blasting vibration velocity is 48.59 while the average attenuation rate of numerical simulation is 56.29 and the relative error is 9.68. In addition, the simulated wavelet packet energy analysis results are basically consistent with the field measured wavelet packet energy analysis results.) the explosion source distance is increased from 20 m to 40 m, the hole aperture is reduced from 160mm to 90 mm, and the number of holes is reduced from three holes to one hole. When the delay time is increased from 25ms to 65ms and from non-presplitting blasting to pre-splitting blasting, the effect of blasting vibration on slope stability is reduced accordingly. Therefore, small aperture blasting, 65 Ms delay blasting and pre splitting blasting should be used in the blasting near the mine slope. In order to ensure the stability of the slope, the method of path coefficient is used to analyze the blasting vibration velocity and main frequency, the distance between the blasting center and the core, the total charge, the maximum charge and the difference in height. According to the correlation between the front resistance line and the rock integrity coefficient, it is concluded that the blasting vibration velocity is greatly affected by the blasting center distance and the maximum charge quantity. On the other hand, the main frequency of blasting vibration is greatly affected by blasting centroid distance and rock integrity coefficient .6) from two aspects of energy source and blasting seismic wave propagation process, scientific and reasonable blasting vibration reduction measures for adjacent slopes are put forward. A set of production blasting parameters and pre-splitting blasting parameters are designed which are beneficial to the production of limestone mines and ensure the stability of slope. According to the above research, the influence of different blasting loads on the stability of slope with structural plane is obtained, and a scientific and reasonable blasting damping measure is put forward to ensure the stability of the slope.
【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】：TD235

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