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空孔直眼掏槽成腔模型理论与实践分析 总被引：5，自引：2，他引：3
空孔直眼掏槽是隧道或井巷掘进的主要方法之一。基于典型空孔掏槽炮眼布置,分析了掏槽眼爆破形成空腔的物理力学过程;建立了空腔形成的物理和力学模型;研究了腔内碎石在高压爆生气体作用下的抛射过程;得出了空腔尺寸的理论计算方法。槽腔岩石介质破碎和外端部漏斗形成取决于掏槽眼装药爆炸动作用;碎石的抛出率与炸药性质、岩石性质和爆破参数有关。理论分析与在某矿进行的48次试验结果有较好的吻合性。 相似文献
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单螺旋空孔直眼掏槽成腔过程数值模拟研究 总被引：6，自引：0，他引：6
采用ANSYS三维非线性动力有限元软件,对单螺旋空孔直眼掏槽的爆炸应力波传播规律与成腔过程进行了数值模拟研究,得到了单元有效塑性应变分布图、节点有效速度分布图、节点时间-加速度历程曲线和炸药爆炸体积扩展过程示意图。结果表明,模拟的爆炸应力波是以柱面波形式传递,这与理论上的爆破应力波传递形式相一致,同时还总结出爆破效果与装药孔至空孔的距离相关的结论。整个数值模拟研究实现了掏槽爆破成腔成型过程和压力传播过程的可视化,对预测掏槽爆破效果和优化爆破设计具有积极意义。 相似文献
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目前国内同行在地勘井巷掘进中，常用直线掏槽爆破，掏槽眼和空眼比较多，而且炮眼的平行度要求较严格。一般的凿岩工用气腿式凿岩机钻眼，难于保证精确的炮眼平行度。为此，我们试验一种渐进式直线掏槽爆破，掏槽炮眼比较少，炮眼平行度要求也不 相似文献
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立井冻土爆破的理论与实践 总被引：4，自引：0，他引：4
结合冻土爆破破坏特征,从理论上分析探讨了立井冻土掘进掏槽爆破和光面爆破机理及参数设计,再在实验室中进行模型试验研究,然后将试验结果应用于工程实践去验证和完善. 结果表明:立井冻土掘进爆破以浅眼多循环为宜,眼深Lb =1.2～1.4m;直眼掏槽、周边光爆,较为合理的掏槽参数为:槽眼布置圈径%D%=1.0～1.2 m,眼距a=500～700 mm,单位耗药量q=2.2～2.8 kg*m-3;较为合理的光爆参数为:周边眼距E=500～600 mm,光爆层厚度W＝500～700 mm ,炮眼密集系数m＝0.8～1.2,炮眼装药集中度%q%L=120～160 g*m+-1,空气垫层或空气间隙不偶合装药结构. 相似文献
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为解决煤矿下山巷道爆破掘进中普遍存在的循环进尺小、炮眼利用率低、爆后矸石堆积迎头、留底严重等问题,基于“裂槽、抛碴”思想,有机结合直眼和斜眼掏槽的各自优点,设计了含抛碴眼的楔形掏槽方式这一新型掏槽结构。在华恒矿-1 000水平副暗斜井,通过改变掏槽眼的布置位置和起爆顺序、设置抛碴辅助眼等措施,结合弧形和直线形组成的混合型辅助眼布置方式,制定出3种下山巷道爆破掘进技术方案并进行现场试验。通过掘进进尺、残眼深度、巷道成型、抛碴距离、矸石块度、矸石高度等指标,评价设计方案,最终优选出一种综合指标最好的爆破方案。该矿采用此技术,月进尺提高了40%以上,验证了该技术在下山巷道爆破掘进中的有效性。 相似文献
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我队在江西某矿进行地质勘探工作。70％的平巷和探采天井工作量均在含白银矿石榴子石矽卡岩中掘进，矿岩呈层状，纹理清晰，节理不发育，岩石坚固性系数f=18，具韧性。该矿一直沿用直线龟裂和螺旋掏槽爆破，炮眼利用率低，1989年7月掘进51个循环，平均仅达50％，最低的为20％，8、9两月虽通过外延和内部摸索，但仍只分别为63％和68％。9月下旬起试行五星掏槽，掘进19个循环，平均达83％。1990年经对炮眼参数，几何形状，起爆顺序和辅助眼布设作相应调整后，使炮眼利用率稳定在85％以上，并减少了炮眼个数，降低了材 相似文献
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本文运用断裂力学原理和现代裂纹技术提出了聚能掏槽爆破新方法,并设计出了三星聚能掏槽药包,进行了药包切割钢板、铝板、岩体及聚能掏槽爆破的实验室及现场试验.试验表明,聚能掏槽爆破方法可使坚硬岩石的爆破效率从70%提高到95%左右. 相似文献
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PDC钻头切削齿受力随布齿密度变化关系研究 总被引：1，自引：0，他引：1
采用不同布齿方式的３个ＰＤＣ切削齿同步连续切削转动的岩石为模拟井底钻头切削齿实际工作状态，用切削岩石时相同的布齿参数切削砂轮来磨损切削以模拟切削的以模拟切削齿磨状态，试验研究了不同磨损程度的切削齿受力与布齿密度的关系。 相似文献
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It is well accepted that there is a transition of failure mode from ductile to brittle with increasing depth of cut during rock cutting process. Rock failure modes affect cutting efficiency, and knowledge of the failure transition is essential to the determination of optimum cutting parameters. The critical transition depth can be linked with rock properties. In this study, an attempt was made to model rock cutting process and to check the dependence of the critical failure mode transition depth on the brittleness of rock. For this purpose, dimensional analysis was first performed to establish the correlations between rock macro‐properties and micro‐parameters for discrete element simulations. Following the specimen calibration procedure, two types of synthetic rocks having approximately the same uniaxial compressive strength were generated as the synthetic specimens for simulating the rock cutting process. The first specimen was created using conventional model construction method with identical bond strengths between particles, giving rise to undesirably high indirect tensile strength. The second specimen was created using a proposed clustering algorithm such that the ratio between the tensile and compressive strength matches reasonably well with that of real rocks. The results of rock cutting simulations demonstrate that failure mode transition took place in both models, but for the clustered model the transition emerged at a shallower cutting depth. A further exploration was made to derive the critical depth for this transition based on the simulations performed on the clustered models. The derived relationship indicates that the critical transition depth decreases as strength ratio or brittleness of the rock increases. This provides a very useful tool for predicting the critical depth which can be used to help cutting tool design and cutting parameter optimisations. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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In this paper, an experimental study on the cut depth, which is an important cutting performance indicator in the abrasive waterjet (AWJ) cutting of rock, was presented. Taguchi experimental design of an orthogonal array was employed to conduct the experiments. A variety of nine types of granitic rocks were used in the cutting experiments. The experimental data were used to assess the influence of AWJ operating variables on the cut depth. Using regression analysis, models for prediction of the cut depth from the operating variables and rock properties in AWJ machining of granitic rocks were then developed and verified. The results indicated that the cut depths decreased with increasing traverse speed and decreasing abrasive size. On the other hand, increase of the abrasive mass flow rate and water pressure led to increases in the cut depths. Additionally, it was observed that the standoff distance had no discernible effects on the cut depths. Furthermore, from the statistical analysis, it was found that the predictive models developed for the rock types had potential for practical applications. Verification of the models for using them as a practical guideline revealed a high applicability of the models within the experimental range used. 相似文献
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Tool‐rock interaction processes can be classified as indentation or cutting depending on the direction of motion of the tool with respect to the rock surface. The modes of failure induced in the rock by an indenting or a cutting tool can be ductile and/or brittle. The ductile mode is associated with the development of a damage zone, whereas the brittle mode involves the growth of macrocracks. This is the first part of a series of two papers concerned with an analysis of the cutting and the indentation processes based on using the discrete element method. In this paper, numerical simulations of the cutting process are conducted to reproduce the transition from a ductile to a brittle failure mode with increasing depth of cut, which is observed in experiments. The numerical results provide evidence that the critical depth of cut d * controlling the failure mode transition is related to the characteristic length ? = (KIc ∕ σc)2 with KIc denoting the material toughness and σc its unconfined compressive strength. The nature of frictional contact between the cutter face and the rock in the ductile failure mode is also examined. It is shown that the inclination of the total cutting force is controlled by a multi‐directional flow mechanism ahead of the cutter that is related to the formation of a wedge of failed material, intermittently adhering to the cutter. As a result, the inclination of the total cutting force varies with the rake angle of the cutter and cannot be considered an intrinsic measure of the interfacial friction between the cutter and the rock. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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A two dimensional non-linear finite element simulation model has been developed using a mathematical model for progressive
rock failure for understanding the mode and sequence of rock failure under a drag pick cutter. Rock cutting simulation has
also been done using linear elastic modeling using local stability factor contouring. It has been observed from the simulation
results that during negative rake angle cutting the chipping occurs by shear failure of the elements. Whereas, in positive
rake angle cutting, some elements were observed to fail in shear and some under tension. The predicted peak cutting force
using the developed models was found to be up to 25% higher than the experimental values. The effect of input parameters such
as rake angle, flank wear, depth of cut and rock properties on the predicted peak cutting force has been studied, verified
from earlier experimental studies and compared with some earlier proposed theories on rock cutting. The elastic stress analysis
model based on the stability factor contouring method has also been found to be an effective tool to bracket the expected
peak cutting force for a given operational and rock parameters but failed to simulate the effect of pick geometry (rake angle)
correctly. The non-linear simulation model using progressive rock element failure is superior to elastic linear stress analysis
model by simulating the correct trends for all the rock and machining parameters. 相似文献
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运用钻石光学效果观察仪采集合成立方氧化锆（CZ）样品的光学效果的实测图样,采用中国地质大学（武汉）珠宝学院石斌博士研发的宝石切工仿真分析系统模拟样品的光学效果仿真图样及可视亮度。通过量化程序统计样品实测图样的亮度值,以及仿真图样的亮度值。研究在入射角度为7．12°-12．58°的环形光源下,样品的实测亮度与主要切工参数的关系;对比仿真图样与实测图样的异同;分析样品可视亮度与仿真图样的统计亮度值的变化趋势,发现样品仿真图样的统计亮度值与模拟的可视亮度变化趋势基本一致;对称性较好样品的仿真图样与实测图样较一致;亭角38．5°-41．5°,冠角27°-39°之间一些特定组合的样品具有较高的亮度。结果表明,通过采集、分析图样测量圆明亮琢型宝石实际亮度的方法是准确可行的;对称性或某些参数的细微变化都可能引起样品亮度很大的变化;亮度较高样品的亭角、冠角满足加和规律,即亭角减小必须与需锫增加相静会．才鲐呈拥掂高的毒序 相似文献
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综合利用岩心分析、测井及动态开发资料研究了扶余油田西一、二区北的剩余油分布规律，所研制的油田中、高含水期确定小层剩余油分布图，解决了油田开发中的动态预测小层剩余油分布的难题，并且对１９８２年和１９９２年底的剩余油分布规律作了分析。 相似文献
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通过卤(盐)井的维修施工,消除各种井内故障,恢复生产能力,使卤(盐)井达到设计开采量,同时也能最大程度利用地下宝贵的资源。技术割管在卤(盐)井可将悬挂在溶腔内的技术管按设计要求割断,并掉入溶腔,从而实现卤(盐)井的第二梯度开采;对对接井而言,则可排除溶腔内堆积的沉淀物对直井的不利影响,实现斜井进水直井出卤开采方式,最大程度地满足正常的卤(盐)开采运行模式。我单位经多年的工程实践,已形成了较合理有效的卤(盐)井维修施工工艺,现介绍卤(盐)井割管维修施工中一些关键工艺和施工经验。 相似文献
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通过对水淹层地球化学资料的分析,总结出了不同程度水淹层的地球化学特征,提出了利用地球化学资料从定性识别到定量评价的水淹层评价思路,建立了水淹层水淹程度定性识别方法、剩余油饱和度和含水率定量评价模型.对储层物理性质、岩性、流体性质、水淹程度不同的108口井529层水淹层进行了评价,剩余油饱和度与经校正后的密闭取芯井岩芯分析剩余油饱和度非常接近,水淹级别、含水率与单层试油结果一致.证明利用地球化学资料评价水淹层方法是可行的,结果是可靠的,该方法有很好的推广应用前景. 相似文献