【作者】 柴修伟；

【导师】 梁开水；

【作者基本信息】 武汉理工大学 ， 采矿工程， 2009， 博士

【摘要】 当前资源已成为制约人类发展的三大因素之一,而在陆地资源日趋减少的形势下,世界各国纷纷把目光投向海洋、湖泊、港湾等水下可利用资源。水下爆破技术是开采水下资源和水下施工的一个重要手段,水下爆破技术二战前主要用于军事目的以及零星的水下炸礁工程逐渐扩展到民用行业,如航道疏浚,海港开发,河口、港口整治,沉船解体,交通和水电工程建设,以及科学研究试验等方面。随着安全环保意识增强和钻孔机械设备的改进,水下炮孔爆破逐渐取代水中爆炸和水下裸露爆破成为水下爆破的主要施工方法。水下炮孔爆破的炸药埋藏在岩石或水工结构中,炸药爆炸时的能量分布、冲击波的传播特性以及边界条件的影响都与炸药直接在水介质中爆炸产生的水中冲击波特性有所不同。文章在探讨水中爆炸的基本理论和水中爆炸产生的水中冲击波传播特性及衰减规律的基础上,采用数值模拟方法,对水下炮孔爆破在单自由面、两个自由面的情况下,炸药在岩石中爆炸后产生的应力冲击波在水介质中的传播特性和衰减规律问题展开研究,并取得了以下研究成果:1)对一个炮孔在单自由面、水介质堵塞时炸药产生的水中冲击波进行数值计算发现,炮孔附近的水中冲击波压力峰值是动水运动和气泡脉动的压力的叠加,动水运动和气泡脉动的影响主要是垂直向上;远离爆源时,由孔口局部炸药产生的水中直达波成为水中冲击波的主导波,水中直达波以孔口中心为球心向四周传播。在距炮孔轴线11m后的水中冲击波衰减规律与现场试验数据所回归的衰减规律比较吻合。在其它因素不变的情况下,将不同水深时水中冲击波传播的衰减规律相比较,随着水深的增加,水中冲击波压力峰值在竖直方向上衰减变得更快;而水平方向上,水中冲击波压力峰值在爆源附近区域衰减变快;距炮孔轴线11m后,水深使得水中冲击波衰减变慢,水中冲击波的影响范围变大。2)在两个自由面的水下台阶爆破,水中冲击波的产生机理与单自由面时有所不同。通过对水下台阶爆破最小抵抗线方向、平行台阶坡顶线方向和垂直水底三个方向的水中冲击波传播特性的研究,结果表明:水下台阶爆破的水中冲击波的压力由炮孔中所有药量来决定的,水中冲击波压力在垂直水底方向衰减最快,其次是平行于坡顶线方向,最小抵抗线方向的衰减是最慢的。在其它影响因素不变的情况下,水深5m、10m、15m时水深变化对水中冲击波的传播特性和衰减规律基本没有影响。3)堰内充水爆破拆除围堰时,混凝土围堰内侧中的水平炮孔爆炸产生的水中冲击波有方向性的,炮孔轴线上的水中冲击波压力最大,随着测点偏离炮孔轴线,水中冲击波压力逐渐变小。水中冲击波压力峰值在炮孔轴线上衰减比垂直于炮孔轴线向上衰减慢。某水利工程碾压混凝土围堰爆破拆除的水中冲击波实测数据和水中冲击波波形,验证了围堰水平炮孔产生的水中冲击波具有方向性,炮孔轴线方向上的水中冲击波强度最大,偏离炮孔轴线,水中冲击波压力逐渐衰减。更多还原

【Abstract】 Currently natural resources has become one of three factor for restricting human being development, however, in the situation of land resources gradually lessen, the eyes of each country in the world were trained on the underwater available resources in the sea, lakes, and harbors. The underwater blasting technology was an important means to underwater resources exploration and underwater construction, and its application was extended gradually from the military purpose and scattered underwater reef blasting to civilian industry, such as channel dredging, harbor, estuary exploitation and control, wrecked ship disintegration, transportation and water-power engineering construction and scientific study and test, etc. Following strengthen of safety and environmental awareness and improvement of drilling machines, the underwater borehole blasting become gradually the principle work means. Explosive in underwater borehole blasting was embedded in rock or hydro-structure, and the energy distribution, shock propagation and boundary condition influence were different from the underwater explosion and water surface explosion.On the basis of research results of underwater explosion fundamental theory and water shock propagation and attenuation characteristic, this paper combined the numerical simulation and studied the propagation and attenuation characteristic of shock in water produced by the explosion in rock of underwater borehole blasting under single free surface and dual free surface condition, and reached the study results as follow.1) Through simulating the shock in water produced by a single borehole on single free surface and damping in water condition, the water shock peak pressure was the superposition of dynamic water pressure and bubble pulsation peak pressure, and the effect of dynamic water motion and bubble pulsation was vertical direction. The water direct wave produced by the partial explosives in borehole orifice become the principle wave of shock in water away from the explosion source, and the direct wave propagated around in center of borehole orifice. The attenuation rule of shock in water after 11m away from borehole axes was confirmed to the attenuation rule regressed from the site test data. On the other factor no changed, the attenuation rule of shock in water of different water depth was compared. Following the water depth increasing, the water shock peak pressure attenuated more quickly in vertical direction. In the horizontal direction, the peak pressure attenuation become more quickly near explosion resource but become slow after 11m away from borehole axes.2) In underwater bench blasting with dual free surface, the mechanism of shock in water was different from single free surface condition. Through study the water shock propagation characteristic in minimum burden direction, parallel to bench edge direction and vertical to water bottom direction of underwater bench blasting, the results shows that the water shock of underwater bench blasting was produced by the whole explosive amount in borehole, and the water shock attenuated most quick in vertical direction, the parallel to bench edge direction’s was next quick and the minimum burden direction’s was the slowest. Under other factors no changed condition, the 5m, 10m, 15m water depth were, in the main, no influence on the propagation characteristic and attenuation rule of shock in water.3) The cofferdam was demolished by blasting with inner full water, water shock produced by horizontal borehole explosion in inner side concrete of cofferdam had directivity, and the maximum pressure of water shock existed in borehole axis direction, and the water shock pressure become small following away the borehole axis. The peak pressure attenuation of shock in water in borehole axis direction was slower than the direction vertical to the borehole axis. The monitor data and waveform of shock in water of a hydraulic engineering RCC cofferdam blasting demolition verified the directivity of water shock produced by cofferdam horizontal borehole, the maximum water shock pressure in borehole axis and the water shock pressure declined by away the borehole axis.更多还原