空气间隔装药爆炸冲击荷载作用下混凝土损伤分析

采用JHC混凝土损伤演化模型,模拟计算了不同空气间隔装药结构情况下炮孔近区岩石损伤破坏机制,分析了空气层比例以及起爆方式对爆破效果的影响。计算表明,不同空气层位置及比例会产生不同的爆破效果,并能运用于不同的爆破目的。空气层比例与炮孔粉碎区大小成反比,空气比较小时可以用于梯段爆破,而空气比较大时可用于预裂或光面爆破。对于梯段爆破、反向起爆（空气层位于上部）和中间起爆（空气层位于中间）的效果要好;起爆方式对梯段爆破效果的影响要比预裂和光面爆破效果明显。     

超深孔一次成井微差爆破技术研究

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。     

导爆管在小断面竖井施工中的应用

我队机掘分队,曾在某金矿的43m勘探竖井的施工中,为克服和解决因岩石坚硬,涌水量多,采用火雷管起爆瞎炮率高,爆破效率低,点炮安全性差的困难,推广使用了非电导爆管起爆系统和起爆方法,解决了火雷管爆破中的不安全因素,实现深井爆破一次性点火,起爆精度高,提高了爆破效率.     

石笕岭隧道掘进爆破方案设计

分析了石笕岭隧道短台阶掘进爆破施工中存在的问题，在使用自制简易凿岩平台可实现全断面掘进钻眼条件下，提出了全断面掘进爆破方案。采用工程类比法设计，并通过场试验确定了合理适用的光面爆破参数。探讨了在隧道掘进中，利用非电毫秒差雷管孔外微差接力传爆，扩大起爆雷管使用段数的方法。     

宽级配废石的高排土场稳定性研究

宽级配废石的一坡到底的高台阶排土场具有明显的粒径分级特征,传统稳定性分析方法将其简化为多层各向同性的均质土体,却实质性忽略了排土场粗粒土各粒组分布的不均匀性和随机性,导致难以获得其边坡稳定性的合理结论。依托江西某铜矿高台阶排土场,借助自编元胞自动机程序EPOHHM,采用5组窄级配粗粒土表征了高台阶排土场的粒径分级现象,模拟了各粒组散体分布的不均匀性和随机性,分析了不同工况下排土场的位移场及塑性状态,系统地探讨了不同堆排模式下排土场边坡的安全稳定性,提出了一种宽级配废石的高台阶排土场稳定性的精细化分析方法。研究结果表明,排土场发生“拉-剪”破坏;土体中上部有圆弧形滑坡趋势,下部变形表现为沉降,顶部平台产生拉剪裂缝。仅考虑散体力学强度时,底部粗颗粒（ 100 mm）含量的增加对排土场起显著的稳固作用,“单台阶全段高”的堆排模式比“全覆盖式多台阶”更有利于宽级配废石的高排土场安全稳定。研究成果将为保证明显粒径分级的排土场的长期安全稳定提供指导,也为今后分析此类工程问题提供借鉴。     

水压与钻孔爆破联合拆除水塔

:道县机械厂水塔高 15m ,塔身为砖混结构 ,上部储水池为钢筋混凝土结构 ,采用联合拆除法 ,即塔身采用钻孔爆破法 ,储水池采用水压爆破法。介绍了爆破参数设计、起爆方法、施工与安全防护等技术     

既有隧道扩建爆破振动数值模拟研究

基于原有隧道改扩建拱顶塌腔段扩建开挖,系统研究了多临空面条件下岩体爆破振动规律。采用完全重启动数值方法和拉格朗日算法分析岩体爆破振动规律,模拟爆破振动对隧道塌腔加固区和既有隧道围岩的影响,并获得了特征点的振动速度和衰减规律。数值模拟的最大振速符合爆破振动安全允许标准的要求,从而验证了爆破设计的可行性,并指导了爆破施工。同时,对隧道塌腔段开挖进行爆破振动监测。通过对比分析现场振动监测数据,数值模拟与现场监测结果吻合。结果表明,采用拉格朗日算法和完全重启动数值模拟方法可以描述隧道多孔毫秒延期爆破破岩和质点振动传播规律。该研究结论对隧道多孔毫秒延时控制爆破工程具有参考和指导意义。     

多孔同段爆破漏斗形成机理的数值模拟研究

采用ANSYS/LS-DYNA非线性三维动力有限元软件,对岩石在多孔同段爆破作用下的应力分布与传播机制,进行了数值模拟。得到了不同时刻的应力分布云图和典型单元的应力-时间历程曲线, 根据结果分析研究了应力波传播规律与爆破漏斗的形成过程,探讨了影响爆破漏斗形成的相关因素,并通过现场试验加以验证,试验结果与数值模拟结果相吻合。     

破碎岩体浅埋大跨公路隧道开挖方案对比研究

三车道高速公路隧道通常跨度较大、高跨比较小属于大跨扁平隧道。这种结构型式对围岩稳定和结构受力均产生不利影响,因此施工中有必要通过开挖方案比选确定合理的开挖方法。江苏省宁波-常州高速公路茅山东隧道为上下行分离式双向6车道浅埋大跨扁平隧道。对于破碎的Ⅳ级围岩,针对设计阶段拟采用CRD法和实际施工采用下断面左右分部台阶法的开挖方案在设计支护条件下的三维数值模拟,从理论上分析了下断面左右分部台阶法是可行的。与实际施工过程的监控量测结果进行对比分析,进一步证实了实际开挖方案的合理性。研究成果可以为同类工程的设计与施工提供理论参考。     

基于超剪应力控制的岩爆防治措施研究

简要介绍了断裂型岩爆的超剪应力理论,初步讨论了爆破开挖扰动对超剪应力的影响,并从控制超剪应力的角度建议了相应的岩爆防治方法,给出了工程实例。研究表明,开挖动态扰动将使断裂两侧岩体在较低的超剪应力条件下就产生滑动,另外,高地应力条件下爆破开挖过程中地应力动态卸载扰动可以引起围岩中动态剪应力的增大,直接增大超剪应力,这两种情况都可能导致岩爆的发生。因此,可从控制爆破扰动的角度来控制岩爆的发生,具体措施有炮孔合理布置、起爆网络的优化和加强支护。     

空气间隔装药爆破机理研究

利用爆轰波理论分析了空气间隔装药炮孔内一维不定常激波的相互作用及其在炮孔堵头、孔底的反射过程,同时分析了孔内各点的压力随时间的变化过程,介绍了空气间隔装药爆破的机理及设计参数。基于此,认为应充分利用空气间隔爆破结构的优势,并在梯段爆破中满足以下两个条件：（1）在设计过程中要尽量使稀疏波及从孔底反射的稀疏波传播过程能在整个孔内每一断面都作用到,即稀疏波到达孔底的时间要比从堵头反射的压力波到达孔底要早;（2）反射压力波应该到达空气与爆生气体接触面的时间比从孔底反射的稀疏波到达空气与爆生气体接触面的时间要早。由此通过计算得到了在梯段爆破工程中合理的空气层长度比例值约为30 %～42 %。计算结论与已有实测成果基本一致。     

Finite element analysis of vibrations induced by propagating waves generated by tunnel blasting

Summary The excavation of underground tunnels close to existing substructures or the ground surface presents problems especially when blasting is being carried out. The high intensity waves which are generated and propagated through the rock medium, due to the detonation of explosives, may still have large amplitudes when they reach the ground surface. In order to study the vibration effects due to these propagating waves associated with blasting, a finite element simulation of tunnel blasting has been carried out in this paper.An example of a new tunnel excavated below an existing tunnel has been studied. Even though this problem is three dimensional in nature, due to the large computational efforts involved in three dimensional dynamic analysis, a two dimensional finite element analysis has been adopted. A pseudo-plane strain concept has been used since it has been found that the results obtained using such an approach are more realistic than the conventional plane strain analysis.It is concluded that results from such a numerical analysis could compliment the field investigations to produce guidelines for safe and controlled blasting.     

软弱破碎围岩双连拱隧道安全施工与监测

针对软弱破碎Ⅱ类围岩双连拱隧道采用三导洞施工方法的特点,阐述了其安全施工技术要点,实际施工中,就其监测内容及监测结果进行了实时分析,为隧道安全施工提供了依据,长期监控量测结果表明,该隧道结构是安全的,达到了围岩与支护结构体系安全与稳定的要求,所采用的安全施工措施以及信息化施工方法对类似工程具有指导和借鉴意义.     

Effect of Blast-Induced Vibration from New Railway Tunnel on Existing Adjacent Railway Tunnel in Xinjiang, China

The vibrations of existing service tunnels induced by blast-excavation of adjacent tunnels have attracted much attention from both academics and engineers during recent decades in China. The blasting vibration velocity (BVV) is the most widely used controlling index for in situ monitoring and safety assessment of existing lining structures. Although numerous in situ tests and simulations had been carried out to investigate blast-induced vibrations of existing tunnels due to excavation of new tunnels (mostly by bench excavation method), research on the overall dynamical response of existing service tunnels in terms of not only BVV but also stress/strain seemed limited for new tunnels excavated by the full-section blasting method. In this paper, the impacts of blast-induced vibrations from a new tunnel on an existing railway tunnel in Xinjiang, China were comprehensively investigated by using laboratory tests, in situ monitoring and numerical simulations. The measured data from laboratory tests and in situ monitoring were used to determine the parameters needed for numerical simulations, and were compared with the calculated results. Based on the results from in situ monitoring and numerical simulations, which were consistent with each other, the original blasting design and corresponding parameters were adjusted to reduce the maximum BVV, which proved to be effective and safe. The effect of both the static stress before blasting vibrations and the dynamic stress induced by blasting on the total stresses in the existing tunnel lining is also discussed. The methods and related results presented could be applied in projects with similar ground and distance between old and new tunnels if the new tunnel is to be excavated by the full-section blasting method.     

近距离交叉隧洞爆破对既有隧道的振动影响

结合南山下隧洞下穿温福客运专线钱仓山隧道工程,实时监测近距离交叉隧洞爆破施工对既有隧道的振动影响。实测结果表明,（1）迎爆面位置影响既有隧道断面的爆破振动速度分布;震源距离测点大于30 m时,距离是爆破振动的主要影响因素;震源距离测点小于30 m时,主要影响因素则为装药量与距离。（2）岩体越坚硬完整,爆破振动波传播衰减越慢。采用导洞先行预留光面爆破、导洞爆破掏槽眼和周边眼及底板眼分开起爆、控制最大段装药量等措施,可有效地降低爆破振动影响,控制其对钱仓山隧道的影响,对类似工程有借鉴作用。     

台阶压碴爆破效果遗传神经网络预测

应用遗传神经网络模型对台阶压碴爆破效果进行了预测,增强了预测结果的可靠性。遗传神经网络是人脑的模型,从爆破实例中获取经验知识,并应用专家知识对爆破效果进行预测,取得了符合实际的预测结果,从而,为选择爆破控制参数和取得良好的爆破效果提供了依据。     

Mechanism of tracer blasting

Summary A variety of overbreak control techniques are used during excavation with the drill and blast system. Tracer blasting is used in Canadian underground mines to minimize blast damage and involves placing a low-strength detonating cord along the length of a blast hole prior to charging with ammonium nitrate-fuel oil (ANFO). The results of tracer blasting are not always consistent and its mechanism is only hazily comprehended. In the absence of a clearly defined mechanism, it is difficult to analyse the results of tracer blasting and to identify the factors responsible for the inconsistency of results.A series of bench blasts and pipe tests were carried out to investigate the mechanism of tracer blasting. The evidence indicated partial deflagration and desensitization of ANFO, thus reducing the total available explosive energy. The rock mass surrounding the traced blasthole experienced a low level of ground vibrations. As a result of the continuous side initiation of ANFO, energy partitioning was more in favour of gas energy. A mechanism of tracer blasting has been proposed and the factors responsible for the inconsistency of the results have been identified in this paper.     

混凝土含水裂隙中爆炸压力传播的模型试验研究

爆炸作用下含水裂隙中水压力的分布及传播特征对分析含水裂隙岩体初始裂纹扩展机制具有重要意义。通过含水裂隙的混凝土室内爆炸试验,测量了爆炸时含水裂隙中的水压力,分析了含水裂隙中水压力的荷载特性及传播特征,并研究了裂隙张开宽度及爆炸药量对水压力荷载的影响。试验研究结果表明：爆炸作用下含水裂隙中水压力时程分布呈多峰波动分布,水压力来源包括爆源通过水介质直接传递的荷载及通过混凝土间接传递的荷载,且在不同裂隙长度,荷载峰值主要来源不同;相同装药条件下,含水裂隙中水压力随距爆源距离增大而迅速衰减,裂隙中同一位置水压力大小与裂隙张开宽度呈负相关;混凝土室内爆炸试验含水裂隙中水击波所带能量频谱主要集中在7.8～62.5 kHz,是一种高频信号。随距爆源距离的增加,能量分布向低频集中;水击波频带能量分布特征受爆炸药量及裂隙张开宽度的影响。当量为4.5 g TNT（三硝基苯）乳化炸药装药相比 8.1 g TNT乳化炸药装药爆炸时水击波高频信息更丰富;相同爆炸药量时,随混凝土中含水裂隙张开宽度的增加,水击波频带能量分布峰值呈现向中间频带移动的趋势。     

A Non-Ideal Detonation Model for Evaluating the Performance of Explosives in Rock Blasting

Summary  A new model to predict the non-ideal detonation behaviour of commercial explosives in rock blasting is presented. The model combines the slightly divergent flow theory, polytropic equation of state, simple pressure-dependent rate law and statistical expressions to model the effect of confinement on detonation. The model has been designated as DeNE, an acronym for the Detonics of Non-ideal Explosives. It is aimed at predicting the detonation state and subsequent rarefaction (Taylor) wave to provide the pressure history for different explosive, rock type and blasthole diameter combinations. It enables the prediction and comparison of the performance of commercial explosives in different blasting environments. The unconfined detonation velocity data has been obtained from the testing of six commercial explosives to calibrate DeNE. A detailed sensitivity analysis has been conducted to evaluate the model. The model has been validated using the results of hydrocodes as well as measured and published in-hole detonation velocity data. Author’s address: Sedat Esen, Metso Minerals Process Technology (Asia-Pacific), Unit 1, 8–10 Chapman Place, Eagle Farm, Qld 4009, Australia