【作者】 韩博；

【导师】 马芹永；

【作者基本信息】 安徽理工大学 ， 采矿工程， 2013， 博士

【摘要】 在矿山井筒掘进施工中,主要采用钻眼爆破法。频繁且大规模的爆破作业在完成岩体开挖的同时,不可避免地会产生爆破振动效应,对井壁及周围岩体等产生不利影响。因此,既要充分发挥炸药爆炸所释放的能量,提高井筒工程的掘进速度和效率；又要对炸药的爆炸能量进行有效地控制,将围岩及支护结构等受爆破振动的影响控制在设计要求限度内。针对井筒掘进存在的上述问题,本文结合皖北煤电集团“朱集西矿井井筒与巷道硬岩段高效爆破技术研究”和“恒源煤矿千米深井硬岩段高效爆破与快速掘进关键技术研究”课题研究,在理论分析爆破地震波传播特性的基础上,进行了立井掏槽爆破两圈眼同时起爆、三圈眼延期起爆等不同爆破方案的模型试验研究,并对爆破振动、爆破应变等进行测试与分析；进行工程应用性验证,同时开展爆破振动效应的现场监测与分析,确保围岩及支护结构的稳定性。主要结论如下：(1)以矿山井筒为原型,根据相似理论建立相似准则,确定模型材料、几何形状及爆破参数。采用预留炮眼方法,设计二圈10个炮眼,三圈20个炮眼混凝土试件,进行齐发爆破、延期爆破等不同掏槽方案的模型试验。分析了爆破损伤对声波传播速度的影响规律,并根据声速的变化特征,判别混凝土试件的损伤程度。试验得出,同时起爆能够获得更多能量,掏槽深度大,产生的振动效应大,爆破损伤程度高；延期起爆能够充分利用自由面,掏槽体积大,爆破损伤程度小。(2)对不同掏槽爆破方案的模型试验进行爆破振动测试研究。得到的爆破振动信号水平横向振速最小,水平纵向和垂直方向振速较大且基本相等。同时起爆时峰值振动速度较大,可以获得较大的起爆能量,有利于掏槽爆破,增大槽腔体积与深度；延时起爆时峰值振动速度较小,可以获得较好的成型效果,有利于辅助眼及周边眼爆破,降低超、欠挖量。随着延期时间增大,各段起爆产生的波形彼此相互独立,峰值振速由各段起爆药量决定。在总药量一定情况下,合理的增加段数并控制最大段起爆药量是降低爆破振动强度的有效方法。对爆破振动信号进行了频谱分析,得出爆破试验在模型试件表面产生的振动信号频带较宽,主振频率突出。(3)对不同掏槽爆破方案的112个测点进行爆破应变测试分析。得到有效应变波形,将应变片电压值通过公式换算为应变值,得到电压信号与动应变的转换关系。分析了应变时间历程关系曲线的变化规律。(4)根据模型试验的研究结果,结合具体井筒工程实际,根据矿山井筒岩石性质、爆破器材性能及凿岩设备条件,优化爆破方案,提出深孔双阶同深掏槽方式,针对炮眼布置方式、炮眼直径、炮眼深度、装药量及微差起爆顺序等对爆破参数进行了优化设计。应用于井筒爆破掘进中,提高了井筒爆破效率及掘进速度,炮眼利用率达到91.7%,并降低了爆破振动对井壁及周围岩体的影响。经过实际应用,对矿山井筒爆破施工的快速掘进与安全具有重要的指导意义,取得了良好的社会和经济效益。(5)通过对爆破振动进行现场测试及分析,得出地震波传播衰减公式、爆破振动信号不同频带的能量分布特征,质点振动速度峰值及时刻与各段起爆的炸药量和延时具有相关性。采用延期爆破方式,控制最大段起爆药量,降低了爆破振动效应,提高爆破效率。更多还原

【Abstract】 The drilling and blasting method is mainly used in the construction of mine shaft. Shaft lining and surrounding rock is subjected to negative impact because of the blasting vibration effect caused by frequent and large-scale blasting operation while completing the rock excavation. Blasting energy should not only be fully used to improve advancing speed and efficiency, but also be effective controlled to keep the vibration of surrounding rock and supporting structures within the limits.In order to solve the problem in shaft excavation, combining with projects "Research on Efficient Blasting Technology for Hard Rock Section of Shaft and Roadway in Zhujixi Coal Mine" and "Research on Key Technology of Efficient Blasting and Rapid Excavation for Hard Rock Section of Deep Shaft in Hengyuan Coal Mine", model tests for shaft cut blasting in two-circle simultaneous blasting and three-circle delay blasting were carried out based on theoretical analysis of blasting seismic wave propagating properties. Blasting vibration and strain tests were also carried out. Moreover, field monitoring and analysis of blasting vibration were presented in engineering application to ensure the stability of surrounding rock and supporting structures. Main conclusions are as follows:(1) According to similarity theory, similarity criterion for coalmine shaft was established; model material, model geometry and blasting parameters were also determined. Blasting holes were reserved during concrete pouring. Two-circle model contains ten blasting holes and three-circle model contains twenty blasting holes to implement simultaneous blasting and delay blasting. The influence of blasting to longitudinal wave velocity was also analysised and the damage degree is determined by longitudinal wave velocity changing. It was found that simultaneous blasting can generate more energy resulting in greater cavity depth, stronger vibration effect, and larger blasting damage; while delay blasting can make full use of free surface leading to greater cavity volume and lower blasting damage.(2) Vibration monitoring was conducted in all cut blasting tests. The results showed that vibration in horizontal was the smallest, and vibration in longitudinal and vertical were bigger and almost the same. Simultaneous blasting could generate larger vibration velocity and more blasting energy, which is good for cut blasting leading to great cavity volume and depth. While millisecond delay blasting could generate smaller vibration velocity and better shape, which is good for auxiliary and surrounding holes blasting, reduces overbreak and underbreak. With the delay time increasing, waveforms were independent to each other, peak vibration velocity was determined by dosage in different relays. When the total dosage was certain, an effective method in reducing and controlling blasting vibration was increasing the relays of detonation and limiting the dosage in simultaneous detonation. By spectral analyses of blasting vibration signals, vibration signal on specimen surface had a wider frequency band and main vibration frequency.(3) Dynamic strain in all cut blasting tests,112measuring points, were analyzed and effective strain waves were obtained by conversion of voltage signal to strain signal. The change rule of strain-time curve was also analyzed.(4) Based on the results of model tests, a cutting mode of double-row with the same depth was put forward according to rock properties, blasting equipment performance and drilling equipment condition. The blasting parameter was optimization designed considering the arrangement, diameter and depth of blasting holes, the charge and firing sequence. In engineering application, advance rate and efficiency was improved, blasting hole utilization reached91.7%, the vibration of shaft wall and surrounding rock was reduced. This would provide guidance for rapid excavation and safe construction of coalmine shaft achieving good social and economic benefits.(5) Through field test and analysis of blasting vibration, the propagation attenuation formula of seismic wave and the energetic distribution of signals with different frequency bands were obtained. The peak particle velocity and time are related to the charge of each interval and delay time. Delay blasting method and controlling maximum instantaneous charge were adopted to reduce the blasting vibration and to improve blasting efficiency.更多还原