Evaluation of space radius formed by blasting pressure with linear charges

Based on the mechanism analysis of space form caused by blasting with linear charges, elastic-plastic model of space form caused by blasting was established in this paper. In terms of state equation of blasting and the balance of quality, evaluation formula based on elastic-plastic to estimate space diameter caused by blasting with linear charges was given. The procedure structure of evaluation was introduced. We did 18 experiments on situ and compared experiments results with evaluation ones. They are correspondent very well. Then a new method of evaluating underground space diameters caused by blasting with linear charges was given. The method has more great guidance significance to the optimism plan of the new blasting technology that utilizes the explosion effect of the explosive to compact the soil to form the underground space.     

Interaction of linear bursting charges

Conclusions In the study of the physical model, we investigated the interaction of blasts generated by a system of two linear bursting charges under full-scale conditions. The mechanism of the “rejection” of gaseous blast products in the stage of acceleration of ejected soil and the mechanism of mound formation at the center of the excavation, which is associated with the characteristic features of the soil's dispersion on detonating two linear charges are ascertained. It was shown that the rate of ascent of the dome of each charge increases monotonically from the velocity of an initial single charge to the velocity value of a charge of the total energy as the charges are brought together as a result of blast interaction. Correspondingly, the width of the funnel for a total-energy charge increases monotonically as the burst rate when the charges are merged into one. Relationships between the final dimensions of the excavation formed by two linear bursting charges with varying intercharge distance are established. Also determined are the optimal distances between excavations and the intercharge distances at which a wide excavation with a flat bottom is obtained without a reduction in burst volume. Conditions favorable to mound formation at the center of the excavation with increasing distance between linear excavating charges are obtained. Relationships between the dimensions of the mound and the embedment parameters of the charges are presented. It is demonstrated that the mound is an independent factor from which it is possible to judge the character of the interaction between two linear excayating charges. O. Yu. Schmidt Institute of Physics of the Earth, Academy of Sciences of the USSR, Moscow. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh No. 3, pp. 72–77, May–June, 1989.     

Shock blasting of ore stockpiles by low-density explosive charges

The authors offer a new approach to the actual scientific and technical task of enhacing efficiency of heap leaching of rebellious oxidized and complex gold-containing ore. The optimization of the leaching technology can be reached through the application of regular shaking and shattering of ore stockpiles using low-density explosive charges.     

多孔球状药包爆破一次成井技术试验研究

以爆破漏斗理论为依据,在与成井试验同一台阶面、岩性相近的场地做了单孔爆破漏斗试验,得出此种岩性的场地最佳埋深比,基于单孔爆破漏斗试验得出的结论和矿山实际情况,通过圆形布孔、不等高分层、设置中间层、多层上下依序起爆和分层间合理延时爆破等技术,成功地将爆破一次成井深度突破到32 m。     

针对建构筑物不同振速要求的隧道爆破药量计算方法

在城区进行巷道或隧道爆破时,许多建构筑物有不同的振速要求,同时满足多种被保护物振速的安全药量计算是一个设计难题。以重庆市隧道爆破为研究背景,建立隧道曲线、被保护物的空间轨迹方程;在地铁、文物建筑、地面建筑3种振速控制下,研究药量-桩号函数关系式:对位于隧道外侧的文物建筑,采用延长建筑物轮廓线将隧道分成若干段并推导相应Q-S分段函数;地铁安全药量根据隧道爆源点到地铁直线的空间垂直距离代入公式获得;其它建筑控制振速下根据爆源至隧道正上方地面距离进行药量计算;利用Matlab软件分别解算隧道各位置的3种药量值,并取其中最小值作为设计药量。     

一次爆破仓储采煤方法分析

文章对一次爆破仓储采煤方法的可行性作出分析,并就该方法中出现的爆破、仓房尺寸、矿山压力和通风安全等问题,提出解决的技术途径。     

Model studies of well stimulation using propellant charges

Plexiglass models were used to investigate crack initiation and propagation from boreholes charged with propellants which deflagrate (as opposed to explosives which detonate).High-speed photography was used to view the propagating cracks and the 7products of deflagrations after ignition occurred. Pressure-time data were obtained from the borehole and in the propagating cracks. The fracture surfaces created were examined and correlated to the type of pressure profile responsible for their generation.Tests were conducted with fluid-filled as well as air-filled boreholes. The effect of grooved boreholes on propagation distance was also determined.Results show that very little borehole deformation (crushing) occurs with a propellant-loaded borehole when compared to an explosively-loaded one. It was also found that the cracks initiate and propagate quickly enough so that the propellant is still burning as it is pushed into the created fractures. The pressurization of the propagating fractures when driven by a propellant appeared to be more complete than when driven by an explosive.     

Ratio of the cavity volumes in confined explosions of concentrated and linear charges

Numerical calculations are performed to obtain a formula showing that confined cavities obtained from the explosions of linear charges are smaller in volume than those obtained from the explosions of concentrated charges containing the same mass of explosive. This phenomenon is explained by the fact that the energy similarity law governing the effect of explosions is satisfied approximately. Institute of Geosphere Dynamics, Russian Academy of Sciences, Moscow. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 58–63, May–June, 1999.     

软岩巷道实现光面爆破的尝试

针对兴隆庄煤矿一采边界泄水巷所处软岩地层特性，设计了一套合理的光爆参数，总结了一些光爆施工方法，从中为软岩巷道实现光面爆破积累了一些经验。     

采区煤仓导硐爆破施工技术

介绍一种圆形垂直式煤仓导硐施工的方法,在煤仓中心适当位置布置一定炮眼,用普通钻机正向钻孔贯穿煤仓,再从下至上逐段控制爆破形成导硐。     

微差爆破对爆破效果的影响

针对宿州符顺石灰石有限公司爆破大块率较高的实际情况,为了确定合理的微差间隔时间,降低爆破块度,南矿区采用普通导爆管毫秒雷管逐孔起爆方法,北矿区采用高精度澳瑞凯导爆管雷管逐孔起爆技术。结果表明:高精度导爆管雷管在降低爆破块度方面具有优越性,爆破效果优良,综合成本低于普通微差爆破。