柱装药双炮孔岩石爆破模型试验

为了合理有效地利用爆炸能量,提高巷道、隧道工程的爆破掘进质量,以砂岩巷道(隧道)掘进中辅助孔、周边孔的岩石爆破为应用背景,通过柱装药双炮孔岩石爆破的模型实验,对装药结构、介质强度、炮孔间距、抵抗等因素对岩石爆破作用效果以及炸药单耗的影响进行了初步研究.试验结果表明,介质强度、不耦合系数、抵抗和炮孔间距与炸药单耗有着密切的关系,并相互作用、相互影响.空气介质对爆炸能量具有很好的缓冲和消耗作用,而水介质对爆炸能量的消耗作用随着介质强度的增大而减小.对于周边爆破,采用空气不耦合装药结构有利于减轻爆破对围岩的破坏作用;当介质强度大于35MPa时,采用水不耦合装药结构有利于提高爆炸能量的传递效率,降低炸药单耗.依据介质强度,合理选择不耦合系数、抵抗和炮孔间距,可在较小炸药单耗的情况下取得良好的爆破效果.     

底部空气柱装药爆破效果模型试验研究

本文通过水泥砂浆模型上的一系列爆破漏斗试验。研究底部空气柱装药的爆破效果，分析了底部空部空气柱长度变化对爆破作用的影响规律，结果表明，底部空气柱长度与装药深度之比为０．４－０．８时，爆破效果最佳，爆破体积比传统的装药结构增大４５％－５５％，显著提高了炸药能量有效利用率。文中提出了底部空气柱效应新概念，探讨了底部空气柱效应的作用机理。     

提高岩石爆破炸药能量利用率的分析

为了提高岩石爆破炸药能量利用率,本文试图从炸药爆轰产物流动与孔壁的相互作用的角度分析孔壁上所受的爆炸压力和冲量,应力波叠加原理和自封闭装药结构,同时还结合这些分析讨论了相应的起爆方法。研究表明,这些论点,对提高岩石爆破效率和经济效益是非常重要的。     

孔底空气间隔装药降振效应数值模拟分析

针对某土石方工程爆破震动峰值振速过大的问题,引入底部空气间隔装药技术,运用大型显示非线性动力分析软件LS-DYNA分别对耦合装药和空气层比例为10％的孔底空气间隔装药进行数值模拟,分析了底部空气间隔装药降振效应.结果表明,底部空气间隔装药有很好的降振作用,减震率在垂直向最大,最高可达25％,为类似工况采用孔底空气间隔装药降振提供了理论依据.     

偏心不耦合装药爆破损伤分布特征数值模拟

偏心不耦合装药结构由于药卷紧贴炮孔孔壁一侧造成岩体中的爆炸能量分布不均,会影响到光面爆破效果,研究其爆破损伤问题可为实际工程施工提供参考依据.文章基于显式动力分析软件,采用材料本构HJC模型,通过观察爆破过程中炮孔周围岩体压碎区、破坏区和裂隙区范围的变化,研究装药位置、耦合介质以及不耦合系数对岩体的爆破损伤分布特征的影...     

夹矸煤层采用空气柱间隔装药结构开采的试验研究

运用爆炸力学理论和弹性波波导理论,分析研究了空气柱间隔装药的爆破机理及空气柱在爆破中的作用效果,并以良庄矿为主要试验基地,结合该矿煤层中夹有不规则煤矸石的地质特点以及现场出现的爆破效率不高等技术问题,从提高循环进尺、减少抛掷量和降低炸药单耗等方面考虑分析,运用研究成果指导现场的爆破作业,对其工作面的爆破参数进行了科学的分析研究.通过调整药包轴向方向、炮孔间距和装药结构等爆破参数,最终取得了良好的爆破效果,到达了增产提效,实现了薄煤层高产的目的.     

岩体巷道光面爆破参数比较分析与应用

光面爆破效果主要取决于岩石条件、炸药性质及光爆参数,岩石条件不同,则光面爆破参数应作相应调整.为将光面爆破更合理地应用于不同条件下的岩石,基于爆炸应力波和爆生气体共同作用理论,提出了普通光面爆破及计入损伤光面爆破参数计算公式.实例及分析说明：基于爆炸应力波和爆生气体综合作用理论的光面爆破计算公式是合理的,适用于不同岩石条件光面爆破参数的确定;在孔深、孔径和装药相同的条件下,岩石越完整,稳定程度越高,其光面爆破的周边眼间距越小;计入损伤时,光面爆破的周边眼间距可适当增大;岩石单轴抗压强度较大,则装药不耦合系数可取较小值,以提高炸药爆炸能量利用率,单轴抗拉强度越高,则光面爆破的周边眼间距值越小.     

装药结构对爆炸能量传递的影响

根据波的能量反射和透射理论，对三种不同装药结构（偶合装药、空气不偶合装药、水不偶合装药）进行了分析，建立了爆炸能量传递系数，并据此探讨不同装药结构对能量传递的影响。     

工程爆破起爆方向研究

利用ANSYS/LS-DYNA软件,采用数值计算方法,从不同起爆方向,对单孔柱状连续装药爆破对孔壁岩石的影响作了比较分析,得出一些有参考价值的结论。岩石爆破时,应尽量采用反向起爆方式,充分利用炸药能量,减少爆破对岩石造成的损伤。     

沟槽爆破参数优化及成本分析

为降低沟槽爆破成本,通过分析初始爆破成本组成结构,了解到孔网参数、超深、起爆网路、施工进度和装药结构是控制成本的关键技术经济指标,通过优化这些技术参数发现:炮孔孔网参数优化是降低成本最有效的方法,对其2次优化后成本降低了33.39%;炮孔超深从1.5 m优化至1.0 m,降低了钻爆成本;把孔外微差延时起爆网路优化为孔内微差延时,不仅减少了雷管用量,而且取得了更好的爆破效果;对于孔深小于10 m的炮孔采用连续装药爆破效果更为理想,大于10 m深的炮孔采用间隔装药,既节约炸药用量,又能减少大块率;对施工进度调整优化后,相应成本降低了7.33%.最终优化后,成本降至初始成本的0.57倍,大幅度提高了企业的效益.     

Model experiment of rock blasting with single borehole and double free-surface

In order to improve the quality of laneways and tunnel excavation by drilling and blasting and by making effective use of explosive energy, a model experiment of rock blasting with a single borehole and a double free-surface was performed with the objective of studying the effect of parameters such as charge structure, free-surface and rock compressive strength on rock blasting. The model experiments indicate that: 1) the smaller the rock compressive strength and density, the more distinctive the cavity expanding action by blasting; 2) the powder factor in an air-decoupling charge structure is larger than that in a coupling charge structure, i.e., the explosive energy in an air-decoupling charge structure transferred to the rocks is less than that in a coupling charge structure; 3) a free-surface improves the utilizations of explosive energy; 4) an air-decoupling charge structure helps to maintain the integrity and stability of wall rock in controlled perimeter blasting, such as in roadways and tunnel excavation by drilling and blasting.     

Radial explosion strain and its fracture effect from confined explosion with charge of cyclonite

Instrumented experiments were conducted in concrete models to study the explosion-induced radial strain and fracture effect of rock-like media under confined explosion with a charge of cyclonite. As a charge was exploded,two different radial strain waves were sequentially recorded by a strain gage at a distance of 80 mm from the center of charge. Through the attenuation formula of the maximum compressive strain(εrmax), the distribution of εrmax and its strain rate(ε) between the charge and gage were obtained. The effect of the two waves propagating outwards on the radial fracture of surrounding media was discussed. The results show that the two waves are pertinent to the loading of shock energy (Es) and bubble energy (Eb) against concrete surrounding charge, respectively. The former wave lasts for much shorter time than the latter. The peak values of εrmax and ε of the former are higher than those of the latter, respectively.     

Study on orientation fracture blasting with shaped charge in rock

1. Introduction Stones for decoration or bowlder are excavated from ore bodies; however, the stones must be excavated with specific technique requirements. Experience shows that blasting is the method with low cost and high effi- ciency. The most familiar…     

Influence of maximum decking charge on intensity of blasting vibration

1 INTRODUCTIONBlasting vibration analysis constitutes thefoundation for studying the control of blasting vi-bration damage and provides the precondition ofcontrolling blasting vibration. In the past , themain means of analyzing and processing for blas-ting vibration signals was the Fourier transform(FT) . By examining considerable blasting vibra-tion data ,researchers found that the signals havedistinct characteristics of short-duration and abruptchange in the signal structure ,including…     

Fracture characteristics of iron ore under uncoupled blast loading

A blasting experiment was conducted on iron ore samples by considering multiple coupling charge coefficients. The resulting internal fracture and damage characteristics were quantitatively analyzed via computerized tomography (CT), scanning, and three-dimensional (3D) model reconstruction. The results show that the iron ore primarily displayed radial and circumferential cracks along the blast hole under an explosive load. When the decoupling coefficient was small, the crack surface was dominated by transgranular fractures in the form of intracrystalline fractures. As the uncoupling coefficient increased, the crack surface exhibited transgranular and intergranular coupled fracture modes. Using fractal theory to analyze crack distribution characteristics, as the decoupled coefficient increased, the body fractal dimension tended to decrease, and the degree of damage gradually decreased. The degree of damage reached a turning point when the decoupling charge coefficient was approximately 1.33. A numerical simulation suggested that the explosion energy transmitted to the iron ore and the effective stress decrease sharply when the decoupling coefficient exceeds 1.33. In some optimal uncoupling coefficient range, excessive fragmentation of the ore body is prevented, thereby allowing full use of the explosive energy.     

小型雷管输出威力的试验研究

采用符合GJB736.3-1989的试验方法,对小型针刺雷管进行装药量匹配、装药密度、雷管壳强度等对比试验,证明合理调整起爆药与猛炸药的装药量、增加猛炸药的装药密度是增强小型雷管轴向输出威力的主要措施.     

Square concrete columns strengthened with carbon fiber reinforced plastics sheets at low temperatures

Twenty-one square concrete columns were constructed and tested. The testing results indicate that bonded carbon fiber reinforced plastics (CFRP) sheets can be used to increase the strength and improve the serviceability of damaged concrete columns at low temperatures. The failure of the specimens, in most cases, takes place within the middle half of the columns. And the failure of strengthened columns is sudden and explosive. The CFRP sheets increase both the axial load capacity and the ultimate concrete compressive strain of the columns. The ultimate loads of strengthened columns at −10, 0 and 10 °C increase averagely by 9.09%, 6.63% and 17.83%, respectively, as compared with those of the control specimens. The axial compressive strength of strengthened columns is related to the curing temperatures. The improvement of axial compressive strength decreases with reducing temperature, and when the temperature drops to a certain value, the improvement increases with falling temperature.     

焦作电厂老厂煤仓漏斗水压爆破拆除

介绍了用水压爆破拆除钢筋混凝土结构物的设计与施工方法.作者对水压爆破的药量计算方法进行了详细的阐述,对药包布置及爆破网路的设计进行了精心的设计和施工,最后达到了良好的预期效果.     

钢桁架连梁-剪力墙结构受力性能的数值模拟

利用数值模拟技术,建立了两个单跨两层钢筋混凝土连梁和钢桁架连梁的剪力墙结构的有限元模型,对比了二者在循环荷载作用下的受力性能,并分析了轴压比、连梁截面尺寸对剪力墙结构的承载力和变形性能的影响规律.分析结果表明：钢桁架连梁的剪力墙较钢筋混凝土连梁的剪力墙,其承载力虽有所降低,但在很大程度上降低了剪力墙的应力和损伤,且其耗能性能和延性均有大幅的提高;轴压比的增大对剪力墙承载力有所提高,但不成比例;钢桁架连梁腹杆截面尺寸对剪力墙结构的承载力有很大影响,弦杆截面尺寸的影响不显著.研究结果对剪力墙的抗震性能的设计计算具有一定的参考价值.