循环爆破加载对露天采场边坡岩体的累积损伤研究

发布时间：2018-06-28 01:42

本文选题：循环爆破作用 + 岩体累积损伤效应　；参考：《江西理工大学》2015年硕士论文

【摘要】：爆破对于矿山、水利和城建等的生产和建设,是快捷且卓有成效的手段,但爆破诱发的震动负面效应也屡见不鲜。对于矿山持续的生产爆破,其对工程岩体的破坏损伤是持续累积的。当累积到一定阈值时,将造成工程岩体的失稳破坏。目前,针对矿山频繁的生产爆破,对工程岩体的累积损伤效应特性研究较少。而循环爆破加载对工程岩体的损伤也是个极其复杂的过程。本文将采用声波仪与爆破振动监测仪,研究矿山频繁生产爆破作用,对爆破中远区工程岩体的累积损伤效应。主要研究内容及成果如下:(1)采用地质钻钻取声波测试孔。即保证了测试孔平行度及孔壁的光滑,能使水很好的与岩壁耦合,也消除了因打孔对岩体的冲击损伤,从而使试验数据误差显著减小。试验过程,采用RSM-SY5声波仪与Minimate Blaster型爆破振动监测仪,在矿山完成了11次循环生产爆破和5次小药量模拟爆破试验。研究频繁爆破加载对露天采场岩体声波波速与累积损伤效应。(2)频繁生产爆破荷载作用下爆破中远区的工程岩体,发生损伤效应的测点数非常有限,而发生损伤效应的测点,则是以损伤增量突然剧增的损伤形式为主。爆心距越小对岩体的累积损伤效应越明显,单段最大药量与损伤强度呈正相关性,爆炸应力波的振动频率及传播方向对岩体累积损伤都有很大的相关性。(3)通过大量的实测数据表明,节理裂解较发育的工程岩体,其受生产爆破循环加载作用的累积损伤形式,以宏观原生裂隙的张开、扩展或贯通等形式为主。微观裂隙的张开闭合扩展等和新裂隙的形成及力学特性的劣化不明显。爆炸应力波对处于中远区工程岩体的作用,岩体表现出的力学性质,主要由宏观结构面的力学性质决定。(4)利用Geo Studio仿真软件,计算边坡在爆破动载荷作用下边坡安全系数的变化。通过软件计算后,反映出爆破对边坡的破坏不仅与质点振动强度有关也与振动频率有关。通过分析安全系数随时间的变化曲线图,还可以反映出,边坡岩体在爆破地震波的作用下发生了损伤现象。本文对频繁生产爆破作用下工程岩体累积损伤效应的研究。为进一步系统研究频繁生产爆破荷载作用下,工程岩体的力学形式及其损伤破坏理论,提供大量现场数据和技术基础。
[Abstract]:Blasting is a quick and effective means for the production and construction of mines, water conservancy and urban construction, but the negative effects of vibration induced by blasting are not uncommon. For the continuous mine blasting, the damage to the engineering rock mass is continuously accumulated. When accumulated to a certain threshold, it will lead to the instability of engineering rock mass. At present, there is little research on cumulative damage effect of engineering rock mass due to frequent mine blasting. The damage of engineering rock mass caused by cyclic blasting loading is also a very complicated process. In this paper, acoustic wave instrument and blasting vibration monitor are used to study the cumulative damage effect of mine frequent production blasting on engineering rock mass in the middle and far area of blasting. The main research contents and results are as follows: (1) the acoustic testing hole is drilled by geological drilling. The parallelism of the test hole and the smoothness of the hole wall are guaranteed, the water can be well coupled with the rock wall, and the impact damage caused by the perforation on the rock mass is eliminated, thus the error of the test data is significantly reduced. In the course of the test, the RSM-SY5 acoustic wave instrument and the Minimate Blaster blasting vibration monitor were used to complete 11 circulatory blasting and 5 small charge simulated blasting tests in the mine. The effects of frequent blasting loading on acoustic wave velocity and cumulative damage effect in open-pit stope rock mass are studied. (2) in engineering rock mass in the middle and far area of blasting under frequent blasting load, the number of damage effect is very limited, but the point where damage effect occurs is very limited. It is to the damage increment sudden increase in the main form of damage. The accumulative damage effect of rock mass is more obvious when the distance of blasting center is smaller, and the maximum amount of charge in single section is positively correlated with the damage intensity. The vibration frequency and propagation direction of explosion stress wave have great correlation with the cumulative damage of rock mass. (3) through a large number of measured data, it is shown that the cumulative damage form of jointed cracked engineering rock mass is subjected to cyclic loading of production blasting. The main form is the opening, spreading or penetrating of macroscopic primary fractures. The opening and closing propagation of microcracks and the formation of new fissures and the deterioration of mechanical properties are not obvious. The effect of explosion stress wave on engineering rock mass in the middle and far region is mainly determined by the mechanical properties of macroscopic structural plane. (4) Geo Studio simulation software is used. The change of slope safety factor under blasting dynamic load is calculated. The results show that the blasting damage to the slope is not only related to the vibration intensity of the particle but also to the vibration frequency. By analyzing the curve of safety factor with time, it can also be shown that the slope rock mass is damaged by blasting seismic wave. In this paper, the cumulative damage effect of engineering rock mass under the action of frequent production blasting is studied. In order to study the mechanical form of engineering rock mass and its damage and failure theory systematically under the action of frequent production blasting, a large amount of field data and technical basis are provided.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD854.6

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