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起爆时差是超深孔一次成井爆破设计中的一个重要参数,合理设计起爆时差和起爆顺序,能够达到先起爆炮孔为后起爆炮孔创造良好自由面和补偿空间,实现筒状硐室分层、分段爆破的目的,并能降低围岩震动破坏。为合理选取起爆时差,基于超深孔微差爆破破岩机制,从理论上推导了一次成井预裂爆破延期时间,掏槽孔与相邻辅助孔、同分段辅助孔、相邻分段辅助孔的起爆时差等计算公式;同时提出了自下而上预裂爆破、先上下后中间光面爆破等6种一次成井起爆顺序。在华恒矿-650矸石仓,结合施工条件合理确定起爆时差等爆破参数,形成爆破设计方案。爆破过程中实现了分层、分段爆破,获得了良好的硐室成型,验证了形成的超深孔微差爆破技术是成功的,其结果对类似工程的实施具有一定的参考价值。 相似文献
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微差爆破降震效果影响因素分析 总被引:3,自引:0,他引:3
依托单段实测爆破振动信号,借助Matlab软件编程,分析了特性各异的子信号在不同微差时间下叠加信号的时频特征,通过引入“降幅率”和“振速比例”的概念,提出了微差爆破叠加信号各特性随微差时间、起爆顺序及子信号特性的变化规律。分析发现,使叠加信号达到一定降幅率的时差并非某一具体时差点,而是多个间断的时差区间,其主频随微差时间的不同呈阶跃锯齿型变化;合理微差时间下,两单段信号的振动特性越相近,干扰降震效果越明显;若装药已定,优先起爆小药量的段别所达到的降震效果更佳。现场试验数据显示,研究结果基本符合微差爆破的现实运作规律 相似文献
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目前爆破震动荷载作用下地下围岩稳定性判别主要依靠单一强度因子的独立阈值稳定性判据,这类判据多为定性分析,没有同时考虑爆破震动三要素的综合作用效果,且未建立稳定性判据与巷道围岩破坏程度之间的定量关系,在实际工程应用中存在一定的缺陷和不足。通过建立爆破荷载作用下的不同类别巷道围岩有限元模型,提取巷道围岩的响应信号,基于小波变换理论建立时间能量密度函数分析巷道围岩响应信号的时、频域特征,进而将时间能量密度曲线与时间轴围成的面积TEDI作为评估爆破震动效应的判别指标,建立了TEDI与巷道围岩损伤程度的定量关系,为进一步完善基于小波能量理论的巷道围岩损伤预警体系奠定基础。 相似文献
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简述了太子矶长江航道整治工程水下控制爆破施工情况和该地区爆破震动监测情况。振动监测表明,工程所设计的爆破方案,采用微差起爆系统对邻近的长江两岸防洪堤是安全的,为控制爆破参数和评价长江堤防的安全提供了科学依据。 相似文献
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深厚淤泥爆破挤淤震动效应测试与控制技术 总被引:2,自引:0,他引:2
结合工程实例,对深厚淤泥爆破挤淤震动效应进行测试和分析,线性拟合得出震动速度随距离衰减规律,并从控制单段最大药量、选择合理微差时间、调整震动波传播方向3个方面对地震效应控制技术开展了试验研究。试验结果表明,这些措施可以有效地控制地震效应。控制单段起爆药量是最根本因素;在相同装药量的情况下,按照大于200 ms的微差时间进行控制,最大震动速度可减小20 %~30 %,药包中心连线方向的震速比垂直于中心连线方向的震速低15 %~25 %。试验结果可为类似工程提供借鉴。 相似文献
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爆破震动对土质边坡动力稳定性影响研究 总被引:8,自引:1,他引:7
采用拟静力化的惯性力法,利用改进了的条分法来计算主动土压力,并考虑爆破地震的时程效应,提出了已有边坡在爆破过程中的动力稳定性系数的新的计算方法。实例证明,所得计算结果综合考虑了爆破震动波传播过程的衰减、频谱结构及相位差等因素的影响,因此该方法在土质边坡稳定分析中与拟静力法相比更具理论基础,其结果也更接近工程实际。 相似文献
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Optimum delay interval design in delay blasting 总被引:2,自引:0,他引:2
Tatsuya Hoshino Gento Mogi Kou Shaoquan 《Fragblast: International Journal for Blasting and Fragmentation》2000,4(2):139-148
The major concern of this research is the reduction of blast vibrations at certain points of foremost importance. A procedure for optimum delay interval design, considering detonation time errors of the electric detonators, was proposed. Using the relationship between the peak particle velocity (PPV) and the delay at certain points of interest which was calculated by means of a computer program by simulating the superposition of the vibration waves emitted from each borehole, one can usually select the optimal delay interval in order to minimize the PPV. But due to the variations in the actual delay caused by the detonation time errors, the expected PPV usually not only depends on the nominal delay but also on the sensitivity of the PPV. Therefore, the selection of the optimum time interval for a delay blast should be based on both the optimum as well as several sub-optimal time intervals as candidates. In addition, the detonation time errors should be taken into consideration. Also, a new design concept, called 'combined delay blasting', which uses electronic detonators, is proposed to further reduce the PPV at the points of interest. Estimated vibration time histories based on this concept and their PPVs indicated considerably favorable results. 相似文献
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饱和钙质砂爆炸响应动力特性试验研究 总被引:1,自引:0,他引:1
钙质砂是一种特殊的海洋沉积物,开展钙质砂在爆炸作用下动力响应特性研究具有重要的理论意义和工程实用价值。通过室内小型爆炸试验,研究饱和钙质砂在爆炸作用下土压力、孔隙水压力和质点振动加速度等参数的变化规律。结果表明:饱和钙质砂中爆炸应力波随距离增大而衰减,但随爆心距增大衰减速度呈减小趋势;随试样相对密度增大爆炸应力波的衰减速度趋缓;爆炸引起的超孔隙水压力在10~30 ms内到达峰值,在前3 min内快速消散,消散幅度达90%以上;双发雷管微差起爆相对于单发起爆,最大单段起爆药量相同,但微差起爆由于爆炸应力波的叠加,使得钙质砂动力响应加剧。与相同试验条件下石英砂爆炸响应对比表明,相同测点处钙质砂动力响应弱于石英砂,应力波在钙质砂中衰减速度远比石英砂快,说明饱和钙质砂对爆炸应力波有着极强的吸收和衰减作用;爆炸近区钙质砂颗粒大量破碎,形成爆炸破碎和压缩区,形成这几个区域所耗损的爆炸冲击能量大约占总能量的25%左右。 相似文献
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Manoj Khandelwal 《Geotechnical and Geological Engineering》2012,30(1):205-217
The purpose of this article is to evaluate and predict the blast induced ground vibration using different conventional vibration
predictors and artificial neural network (ANN) at a surface coal mine of India. Ground Vibration is a seismic wave that spread
out from the blast hole when detonated in a confined manner. 128 blast vibrations were recorded and monitored in and around
the surface coal mine at different strategic and vulnerable locations. Among these, 103 blast vibrations data sets were used
for the training of the ANN network as well as to determine site constants of various conventional vibration predictors, whereas
rest 25 blast vibration data sets were used for the validation and comparison by ANN and empirical formulas. Two types of
ANN model based on two parameters (maximum charge per delay and distance between blast face to monitoring point) and multiple
parameters (burden, spacing, charge length, maximum charge per delay and distance between blast face to monitoring point)
were used in the present study to predict the peak particle velocity. Finally, it is found that the ANN model based on multiple
input parameters have better prediction capability over two input parameters ANN model and conventional vibration predictors. 相似文献
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D. P. Blair 《国际地质力学数值与分析法杂志》1993,17(2):95-118
It is becoming increasingly important, from an environmental viewpoint, to minimize vibrations induced in urban dwellings by blasting. The present study illustrates how the delay interval between blastholes can be chosen to control and minimize the vibration energy within the structural response band of most houses. In particular, it is shown that the only possibility of reducing such energy is to employ a delay interval in the range 10–35 ms. However, the induced vibrations are also dependent upon the accuracy of the delay initiators as well as the level of random fluctuations between each blasthole signature. It is shown that only very accurate electronic delays give the possibility of utilizing fully the delay sequence in order to control structural vibrations. If the vibration emission from each blasthole is totally uncorrelated with that of any other blasthole then the resulting amplitude spectrum of the blast will be totally unpredictable. This situation occurs irrespective of the delay initiation sequence or its accuracy. Under these conditions it is impossible to predict the blast-induced energy lying within the structural response band. 相似文献
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This study evaluates the impacts resulting from quarry-blasting operation on nearby buildings and structures as it generates ground vibration, air blast, and fly rocks. In this paper, first blasting operation and its possible environmental effects are defined. Then the methods of blast-vibration prediction and commonly accepted criteria to prevent damage were introduced. A field experimental work was conducted to minimize the vibration effects at Saribayir quarry as it is an identical case for the many quarries situated in and around Istanbul, Turkey. Although the local surrounding geology and rock mechanics have great influence on vibrations as uncontrollable parameter, the charge weight per delay, delay period, geometric parameters of the blasts were changed to solve the existing vibration problem in the studied quarry. To obtain a realistic result, 10 blasts were carried out and 30 seismic records were made in different places mainly very close the buildings and the other vulnerable structures around the quarry. The evaluation is performed whether the vibration level are within safe limits or not. The prediction equation based on scaled distance concept is also determined, however, it is a site-specific model and need to be updated when the quarry advances. The safe blast parameters which minimize the environmental effect were determined for the Saribayir quarry. 相似文献