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…     

基于人工神经网络的爆破震动速度峰值的预报

介绍了BP神经网络知识，建立了3层BP神经网络模型，并将此模型应用于爆破震动速度峰值的预测，并将其预测值与常规方法的预测值进行了比较．     

新浇大坝基础混凝土爆破安全震动速度研究

在考虑动荷载效应、微裂隙影响、骨料粒径效应等因素对混凝土极限拉应变影响的条件下,提出了全级配混凝土容许拉应变计算公式.在此基础上,结合早期混凝土力学性能及拉应变增长规律,推算了新浇大坝基础混凝土7d内的爆破安全峰值震动速度.与水工建筑物岩石基础开挖工程施工技术规范比较,发现现行规范规定的龄期超过1d的新浇筑混凝土的容许质点峰值震动速度偏于安全,而龄期小于1d的容许质点峰值震动速度则较理论推算值大,可能会引起工程质量事故.     

Study on detonation velocity deficits of bending flexible detonation fuses

In order to study the detonation velocity deficits of bending flexible detonating fuses,a physical model and a theoretical mathematical equation of detonation velocity deficits for bending flexible det...     

水耦合炮孔毫秒爆破成缝试验研究

为研究煤体微差爆破致裂提高煤体瓦斯抽放效率,本文采用模拟试验方法以导爆管长度精确控制微差时间,完成了单孔和三孔试件相似模拟爆破试验.单孔爆破试验结果表明：复合型切缝药包水介质耦合装药是最佳装药结构;不同微差间隔三孔爆破试验结果表明：合理微差间隔爆破可以形成确定方向裂缝并在其他方向形成一定的微裂纹.     

Investigation on the threshold control of safety blasting vibration velocity for the extraction of complicated orebody under railway

The threshold control of safety blasting vibration velocity is a significant process for the underground mining of complicated ore deposit under construction, road, and water. According to the equivalent principle of displacement and velocity of mass point, differential evolution is put forward based on 3DEC dynamic analysis, making the calculation more efficient and accurate. The 3DEC model of the complicated orebody under railway is established according to the topographic maps and geological data of the eastern Pyrite Mine. The stimulus-response distribution of internal stress and displacement fields are demonstrated by analyzing the on-site monitoring vibration displacement and velocity data of the mass point. The reliability of parameter selection, such as blasting simulation waveforms, rock damping, is identified. The safety vibration velocity of railway is set to 4.5 cm/s in line with the requirement of safety blasting rules. Thus, the maximum amount of single-stage explosive in this region is 44.978 kg. The simulation result is in good agreement with the on-site monitoring datum. No displacement and settlement of the 701 railway special line was achieved by choosing the critical amount of the singlestage explosive.     

空气间隔与耦合装药混凝土爆破对比分析

采用动力有限元软件LS-DYNA分析空气间隔装药与耦合装药结构对混凝土介质的破坏机理,结合混凝土模型对两种装药结构进行了光面爆破试验。结果表明,采用空气间隔装药结构进行爆破后,混凝土表面平整度要优于无空气间隔的情况;空气间隔装药结构能调节炸药能量分布,使孔内爆炸压力沿炮孔轴向的分布更均匀,从而提高炸药爆炸能量的有效利用率。     

Influence of charge density and chain length on the interaction between organic anion and montmorillonite

Anionic surfactant sodium dodecyl sulfate (SDS), cationic surfactant cetyl trimethyl ammonium bromide (CTAB) and acrylic acid (AA) were introduced as molecular models to study the interaction between montmorillonite and organic molecules with different charge or chain length. The compounds were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and 13C nuclear magnetic resonance (13C NMR). The results show organic anion could interact strongly with montmorillonite, even the molecules could intercalate into the layers of MMT.     

Vibration velocity and frequency of underwater short-hole blasting

Based on the measuring data of underwater blasting vibration and the regression analysis results of these data, two formulae usually used of blasting vibration velocity were compared. Factors that can affect blasting vibration and frequency were summarized and analyzed. It is thought that the effect of the number of freedom face and burden direction on blasting vibration should be considered during blasting design. Based on the relevant research results and the regression results of these data, a formula to calculate under water blasting frequency was put forward.     

Numerical study on rock fracture and vibration due to blasting

Fracture and ground vibration of rock subjected to different decoupling decked charges are investigated based on the numerical simulation.The dynamic pressure value is studied,which demonstrates that simulation of fracture zone is feasible.Attenuation index of dynamic pressure is 2.06,2.05 and 1.93 for air,water and sand intervals respectively.The small attenuation of sand interval results in the large ground vibration.The predicted vertical vibration waveform and peak particle velocities(PPV) in far-field are in agreement with the monitoring results.The results show that the air and water decked charges can improve the effect of rock fracture in near-field and reduce ground vibration in far-field.     

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…     

边坡爆破振动传播规律的试验研究

从爆破地震效应分析入手,对实验室内混凝土边坡的爆破振动进行试验研究,探讨爆破振动在边坡中的传播规律,并分析了边坡爆破振动对边坡作用机理和地震强度的影响。结果表明,人工预留的预裂缝作为减震沟有明显的减震效果,且表明可运用于实际的边坡爆破工程。     

爆破震动衰减规律的影响因素

爆破震动衰减公式中K和α的取值对爆破震动的准确预报具有重要意义,在理论分析的基础上,根据大量的实测资料,探讨了K和α值的影响因素. 分析结果表明:爆破条件对衰减公式中的 K值影响甚大,在不同的孔径、孔深及装药结构条件下,爆破震动衰减规律会存在很大区别;而岩体及地形条件的改变都会对K和α值造成较大的影响,相对爆源不同方向和距离上的震动衰减规律也是不尽相同的.     

爆破对岩体节理裂隙的影响

利用Ｍｏｎｔｅ－Ｃａｒｌｏ技术模拟岩体的节理裂隙分布的网络结构,从断裂力学的角度出发,分析岩体的节理裂隙的起始扩展和裂纹的止裂,并计算了岩体节理裂隙在爆破作用下的扩展角和扩展量,绘制爆破后的节理岩体的裂隙结构网络图,对研究爆破后岩体的性质具有重要的作用。     

钢筋混凝土冷却塔爆破拆除控振措施研究

在采用控制爆破方法拆除高大建筑物工程中,不可避免会对周围建筑物和设备产生一定程度的振动影响,尤其是建筑物倒塌触地冲击振动的影响.分析了高大建筑物倒塌触地振动的理论计算方法,并提出了相应的控制倒塌触地振动的措施,且简单分析了这些控振措施的控振原理,最后在爆破拆除实践工程中对这些控振措施进行了现场测试检验,测试结果表明,提出的控振措施减振效果明显,实测振速值小于理论计算振速值(最大减振幅度可以达到60%).     

爆破震动对新浇混凝土质量的影响及控制

在邻近岩石开挖爆破的部位进行混凝土的浇筑,短龄期的新浇混凝土容易受到爆破震动的影响,甚至可能会造成质量事故．介绍了在三峡工程施工中新浇混凝土的爆破震动测试成果,分析了产生震速超标的原因,提出了爆破震动控制与超标预防的主要措施．     

爆破地震动频率特性诱导结构破坏分析

爆破地震效应是爆破的主要负面效应,目前多采用爆破质点振动速度来表述地震效应的影响程度大小;同时爆破振动频率特性对结构体的破坏程度也有很大的影响作用,并随工程结构特性而异.从爆破震动频率特性的角度,通过理论计算和分析对爆破振动波频率特性诱导结构体破坏作用进行了研究,结果认为结构体对于介质中传来的爆破振动波的选择放大效应.     

台阶深孔爆破振动控制

对某水电站蠕变体高边坡的台阶深孔爆破振动进行观测和分析,得到考虑高程效应的爆破地震波衰减经验公式.根据该蠕变体高边坡的特点,提出爆破振动控制标准.由经验公式和控制标准,得出蠕变体高边坡新浇混凝土支护区爆破安全控制参量.最后结合该蠕变体高边坡爆破实测,建议了台阶深孔爆破所需要采取的降震措施.从工程实施效果看,该研究成果与结论得到了较好的应用,保障了该工程爆破的顺利完成.     

爆破震动场动力有限元模拟中爆破荷载的等效施加方法

比较了,应用LS—DYNA软件进行爆破震动场数值模拟时的几种不同计算方法的优缺点．结合各方法的特点及爆破震动场模拟的要求,提出了爆破荷载的等效施加方法,即将作用在炮孔壁上的爆破荷载依据圣维南原理等效后,施加在同排炮孔联心线或者面上,以模拟爆炸作用．数值模拟结果表明,不同的爆破荷载施加方法对应的数值模拟结果在近区存在一定差异,但在中远区吻合得较好．因此,使用施加等效爆破荷载的方法对中远区的爆破震动场进行数值模拟是可行的,且该法极大地降低了计算耗费．     

爆破震动场动力有限元模拟中爆破荷载的等效施加方法

比较了应用LS-DYNA软件进行爆破震动场数值模拟时的几种不同计算方法的优缺点.结合各方法的特点及爆破震动场模拟的要求,提出了爆破荷载的等效施加方法,即将作用在炮孔壁上的爆破荷载依据圣维南原理等效后,施加在同排炮孔联心线或者面上,以模拟爆炸作用.数值模拟结果表明,不同的爆破荷载施加方法对应的数值模拟结果在近区存在一定差异,但在中远区吻合得较好.因此,使用施加等效爆破荷载的方法对中远区的爆破震动场进行数值模拟是可行的,且该法极大地降低了计算耗费.