【作者】 康强；

【导师】 叶海旺；

【作者基本信息】 武汉理工大学 ， 采矿工程， 2012， 硕士

【摘要】 在炮孔内装入间隔器,形成空腔取代一部分炸药的装药结构被称为空气间隔装药技术。空气间隔段位置及比例是空气间隔装药最重要的参数,采用合适的间隔位置与间隔比例,在有效降低爆破成本的同时,还可以起到改善破碎效果、减少根底,降低爆破振动效应等作用。以往的空气间隔装药爆破机理研究主要是基于均质、完整岩体的假设条件,而在节理裂隙发育岩体中进行空气间隔装药爆破的研究在我国极为少见。本文分别利用数值模拟及现场试验来研究节理裂隙岩体中的空气间隔装药爆破技术,试图探索最佳的空气间隔装药爆破技术参数。完成的工作及取得的主要成果如下：(1)运用有限元分析软件ANSYS//LS-DYNA,模拟了炮孔内不同空气间隔位置与间隔比例、不同节理裂隙类型与间距条件的空气间隔装药爆破过程,对比分析了不同间隔装药条件下的岩体损伤范围、应力分布与变化规律。模拟结果表明：顶部、底部及中部三种空气间隔装药结构,采用相同空气层比例时,空气层位于炮孔中部的空气间隔装药爆破对周边岩体的损伤范围最大；在空气层周边的应力作用相比连续耦合装药更为持久；与连续耦合装药结构比较,空气间隔装药结构空气层周边岩体在爆破作用过程中受到的拉应力作用相比连续耦合装药更为强烈；岩体节理裂隙对于爆炸应力波的传播有显著影响,节理裂隙越密集,爆炸应力波在向外传播过程中衰减得越快。(2)在贵州典型的喀斯特地貌地区,选取节理裂隙发育与相对较完整的两个试验地点,进行了孔口、孔底、孔正中部、孔中上部、孔中下部五种间隔位置多种不同空气间隔比例条件的空气间隔装药爆破试验,采用块度分析软件Split-Desktop3.0进行块度分析。试验结果表明：在节理岩体中,采用合理间隔比例的空气间隔装药爆破,爆后平均块度、大块率接近连续耦合装药,同时可以有效降低粉矿率,改善爆破块度均匀性；空气层置于炮孔孔口和炮孔中部是最佳的空气间隔装药结构,其合理间隔比例为10～20%；在节理裂隙发育岩体中不宜采用孔底空气间隔装药爆破技术。更多还原

【Abstract】 In bench blasting, air-decking charge is a kind of charge structure. The position and the ratio of air-decking is the most important parameters of air-decking charge blasting, and suitable position and ratio of air-decking could not only reduce the cost of blasting effectively, but also improve the fragmentation effect, decrease toe rock and the blasting vibration.The researches of air-decking charge blasting theory are mainly based on the assuming conditions of homogeneous and intact rock, and it is extremely rare on the research of air-decking charge blasting in jointed and fractured rock mass. Numerical simulation and field test are used to study the air-decking charge blasting in jointed and fractured rock mass, and the best parameters of air-decking charge blasting are explored. The main work and the results obtained are listed as follows.(1) The finite element analysis software, ANSYS/LS-DYNA, is used to simulate the blasting process of air-decking charge blasting with different air-decking positions and ratios, different types of joints and fractures and different fracture spacing. The damage range and stress distribution of rock mass at different conditions of air-decking charge blasting are analyzed comparatively. The simulation results show that the blasting with air-decking in the middle of the hole has the greatest damage to the around rock compared with the air-decking at the top or at the bottom of the charge segment; the action time of stress wave of air-decking blasting is longer than continuous coupling charge blasting; comparing with the continuous coupling charge blasting, the rock around the air-decking has a stronger effect of tension stresses; the joints and fractures of rock mass have a noteworthy influence on the propagation of explosion stress wave, and the more concentrated joints and fractures are, the faster the explosion stress wave decreases.(2) Air-decking charge blasting experiments with different air-decking ratios and five air-decking positions (top of hole, bottom of hole, middle part of hole, middle-upper part of hole, and middle-down part of hole) were carried out at two sites in the typical Karst landforms area in Guizhou province, China, and the rock with developed joints, fractures and relatively intact rock. And the block size is analyzed with the Split-Desktop3.0software. The experiments results show that the average block size and boulder yield of air-decking charge blasting with suitable air-decking ratio in jointed rock mass are close to those of continuous coupling charge blasting, the fine ore ratio decreases effectively, and the block uniformity improves; the best position of air-decking is at the top and at the middle of the charge segment, and the reasonable air-decking ratio is10%～20%; and air-decking charge blasting technology is not suitable to be used in developed jointed and fractured rock mass.更多还原