A two-dimensional kinematic model for predicting muckpile shape in bench blasting

Summary Most existing models of blasting are stress-based and involve many fundamental parameters difficult or impossible to measure in practice. Even a single prediction with such models takes large quantities of computer time, so that calibration becomes a major impediment to their practical use.The model in this paper is based on a simple kinematic approach to modelling muckpile formation. This has the advantage of relative simplicity, while still reflecting the essence of the blasting displacement process. Because of the simple implementation, the model can be calibrated against field data in a straightforward manner and then used for predictions at the same site. The inputs to the model are simply the blast design parameters. The output of the model is a muckpile cross-section, within which contours of diggability or distribution of materials can also be calculated. Case studies have shown that, provided the model is calibrated to the site condition, it will give accurate predictions for altered blast designs.     

地下水流二维、准三维及三维模型模拟结果比较

本文为三种简单的由多个含水层和弱透水层组成的越流含水系统建立了二维、准三维和三维数学模型,并对它们的解进行了比较分析.三种水流系统的二维、准三维及三维数学模型计算结果相互间的偏差随抽水时间的延长而增大,随井距的增大而减小;二维与准三维数学模型计算结果间的偏差随弱透水层越流系数的减小而减小;两种准三维数学模型计算结果间的偏差随抽水含水层与弱透水层间贮水系数比值的增大而减小;考虑弱透水层弹性释水的准三维模型与三维模型的解最为接近,它们之间的水头差当贮水系数比值一定时,随抽水含水层与弱透水层间渗透系数比值增大而减小,且随各向异性比值的增大而增大.     

Environmental impacts of bench blasting at Hisarcik Boron open pit mine in Turkey

This paper presents the results of ground vibration measurements carried out in Hisarcik Boron open pit mine located on the west side of central Anatolia near Kütahya province in Turkey. Within the scope of this study to predict peak particle velocity (PPV) level for this site, ground vibration components were measured for 304 shots during bench blasting. In blasting operations, ANFO (blasting agent), gelatin dynamite (priming), and delay electric detonators (firing) were used as explosives. Parameters of scaled distance (charge quantity per delay and the distance between the source and the station) were recorded carefully and the ground vibration components were measured for all blast events using two different types of vibration monitors (one White Mini-Seis and one Instantel Minimate Plus Model). The absolute distances between shot points and monitor stations were determined using GPS. The equation of square root scaled distance extensively used in the literature was taken into consideration for the prediction of PPV. Then, the data pairs of scaled distance and particle velocity obtained from the 565 event records were analyzed statistically. At the end of statistical evaluation of the data pairs, an empirical relation which gives 50% prediction line with a reasonable correlation coefficient was established between PPV and scaled distance.     

三维高密度电法用于工程勘查的试验

国内三维高密度电法在工程上的应用,大都采用二维数据反演,通过三维成图软件把视电阻率剖面连成三维视电阻率分布立体图,而很少将三维数据拼接在一起,通过三维软件反演。结合管线探测,对真三维高密度电法进行了探测试验,并取得了良好的勘探效果,为三维高密度电阻率法的进一步推广提供了宝贵的实践经验。     

Generalized contact model for polyhedra in three‐dimensional discontinuous deformation analysis

We present a generalized contact computation model for arbitrarily shaped polyhedra to simplify the contact analysis in discontinuous deformation analysis. A list of generalized contact constraints can be established for contacting polyhedra during contact detection. Each contact constraint contains information for 2 contact points, unique contact plane, and related contact modes (open, locked, or sliding). Computational aspects of the generalized contact model include identification of contact positions and contact modes, uniform penalty formulation of generalized contact constraint, and uniform updating of contact modes and contact planes in the open‐close iteration. Compared with previous strategies, the generalized contact computation model has a simpler data structure and fewer memory requirements. Meanwhile, it simplifies the penalty formulation and facilitates the open‐close iteration check while producing enough accuracy. Illustrative examples show the ability of the method to handle the full range of polyhedral shapes.     

深部矿产资源立体地球化学勘查方法技术体系

深部矿产资源的勘查是战略性矿产资源勘查的一个重要方面。找矿实践证明，化探方法技术在矿产勘查乃至深部找矿中发挥了重要的、不可或缺的作用。找矿工作的不断深入和找矿难度的不断加大，促使化探方法技术不断的发展和完善，在传统方法技术的基础上，研发出了许多新的方法技术。本文从方法论和系统论的角度出发，对现有的找寻深部隐伏矿盲矿的有效化探方法技术进行了系统的归纳和总结，提出了立体地球化学勘查方法技术体系的概念，将立体地球化学勘查方法技术划分为地面地球化学测量方法技术和地下地球化学测量方法技术，建立了深部矿产资源立体地球化学勘查方法技术体系。不同的方法技术有不同的优势和不同的适用条件，实际工作中应当根据不同的勘查阶段，不同的勘查目的和不同的地质地球化学条件选择不同的立体方法技术组合才能发挥出最大效益，取得最大效果。     

基于量纲分析的岩石相似材料抗压强度计算模型

物理相似模型试验是复杂、难采矿技术研究的有效手段,而岩石相似材料物理力学特性的研究是试验有效进行的前提。根据相似原理和岩石的力学特性,论证了岩石相似材料单轴抗压强度的力学代表性。统计并分析了影响岩石相似材料单轴抗压强度的一系列因素,基于量纲分析的方法构建了岩石相似材料单轴抗压强度与砂粒径、配比材料总量、充填材料（砂）用量、水用量、养护方式等重要因素间的无量纲计算模型,结合岩石相似材料配比试验得到了定量关系式。选取3组具有代表性的岩石相似材料配比试验对所建立的单轴抗压强度计算关系式进行验证,其计算结果与实验室实测结果相吻合,平均误差为4.20%,定量关系式在岩石相似材料参数的研究上具有一定的合理性。研究结果可以为相似材料物理力学参数的预测及岩土工程物理模型试验相似材料的高效选取提供参考。     

宝昌火山盆地骆驼山地区781矿点铀矿化 三维模型与定位预测

宝昌火山盆地骆驼山地区781矿点位于燕辽构造岩浆活动带西段,是著名燕辽铀成矿带内新近勘查发现的重要矿化区之一。通过对矿区73个钻孔、地形、地层及剖面资料的综合研究,利用Surpac三维软件首次建立了781矿点铀矿化的可视化三维模型,直观地显示了地形、地层、构造、矿体的空间变化特征。地层、构造及矿体三维模型联合研究表明,新识别出的Fa隐伏断裂是最直接的导矿构造和控矿构造,上侏罗统玛尼吐组火山地层为重要含矿层和铀源层。掌握781矿点关键控矿因素,结合矿体空间赋存、分布规律等研究结果,利用Surpac软件在深部定位预测找矿靶区Ⅰ区和Ⅱ区,其具有较精确的空间三维坐标,对深部找矿具有重要指导意义。     

三水模型在腰英台油田储层测井解释中的应用

腰英台油田青山口组储层岩性致密, 低孔低渗, 孔隙结构复杂, 纵向和横向变化大。用传统测井解释模型往往造成解释级别较低, 与测试结果吻合率不高等情况。本文对三水模型进行改进, 并进行了数据处理和解释评价, 利用岩芯分析资料分区块、分层段分别确定模型的参数, 克服了三水模型参数多且不易确定的难点。在研究区致密含油层、低阻油层评价及油水界面划分上取得良好的应用效果, 提高了油气储层解释的可靠性。     

井下采掘三维定位自动监控系统功能架构设计

设计了井下采掘三维定位自动监控系统的总体结构,详细介绍各个功能模块的设计原理及系统实现的功能。应用三维GIS技术J、ava3D技术建立了矿山三维可视化平台,并在此基础上与矿山井下人员定位系统、矿业产量远程监控系统,集成开发了井下采掘三维定位自动监控系统,实现了井下采掘的实时监控、人员实时定位,降低了矿山开采的安全隐患,提高了对矿山开采的监管力度,能够为矿产资源开发与保护、矿山安全管理等提供信息服务。     

A three‐dimensional displacement approach for analysis of laterally loaded piles in nonhomogeneous soil

An analytical approach using the three‐dimensional displacement of a soil is investigated to provide analytical solutions of the horizontal response of a circular pile subjected to lateral loads in nonhomogeneous soil. The rocking stiffness coefficient of the pile shaft in homogeneous soil is derived from the analytical solution taking into account the three‐dimensional displacement represented in terms of scalar potentials in the elastic three‐dimensional analysis. The lateral stiffness coefficient of the pile shaft in nonhomogeneous soil is derived from the rocking stiffness coefficient taking into account the rocking rotation of a rigid pile shaft. The relationship between horizontal displacement, rotation, moment, and shear force of a pile subjected to horizontal loads in nonhomogeneous soil is obtainable in the form of the recurrence equation. The formulation of the lateral displacement and rotation of the pile base subjected to lateral loads in nonhomogeneous soils is presented by taking into account Mindlin's equation and the equivalent thickness for soil layers in the equivalent elastic method. There is little difference between lateral, rocking, and couple stiffness coefficients each obtained from both the two‐dimensional and three‐dimensional methods except for the case of Poisson's ratio near 0.5. The comparison of results calculated by the current method for a pile subjected to lateral loads in homogeneous and nonhomogeneous soils has shown good agreement with those obtained from analytical and numerical methods. Copyright © 2017 John Wiley & Sons, Ltd.     

考虑非饱和浸润层厚度和累积入渗量的改进Green-Ampt模型

矿山内排土场因其储量大、结构松散和强度低等特点,在降雨条件下极易产生侵蚀或整体失稳破坏,因此降雨入渗分析对预测内排土场稳定性至关重要。以元宝山露天煤矿内排土场为原型,按相似试验理论进行物理模型试验,研究降雨入渗特征,根据试验结果对经典Green-Ampt入渗模型进行改进。结果表明：雨水入渗过程中,随着浸润锋的向下运移,坡面侵蚀由溅蚀凹槽开始,逐渐过渡为径流侵蚀,最后呈现为溯源侵蚀破坏,整体呈现平行于坡表面的浅层滑坡特征;浸润锋之上非饱和浸润层的存在,导致经典Green-Ampt模型计算结果不准确;在考虑浸润层厚度和累积入渗量基础上,推导出改进的Green-Ampt模型;改进后的Green-Ampt模型为分段函数,能够反映降雨入渗使坡面由非饱和向饱和过渡的实际特征。验证结果显示,使用改进模型,浸润锋入渗深度和累积入渗量的预测精度显著提升,虽然冲蚀破坏和初始含水率的差异导致降雨入渗后期的预测精度有所下降,但相关结果对煤矿内排土场降雨初期稳定性分析具有重要意义。改进后的Green-Ampt模型的计算结果与实测数据更为接近,能为分析露天煤矿内排土场降雨入渗规律及边坡稳定性研究提供参考。     

全长粘结式锚杆加固洞室抗爆性能试验研究

通过模型试验, 研究了在平面装药爆炸应力波的作用下,全长粘结式锚杆加固洞室抗爆性能。试验结果表明,通过分析自由场压力-时程曲线,证明试验数据可靠;经过加固的洞室拱顶位移峰值减少明显,当比例距离为5.23 cm/g1/2时,洞室发生破坏;在平面波的作用下,两个洞室洞壁各个位置都产生压应变,最大应变出现在拱脚处,随着比例距离减小,拱顶应变峰值先增加后减小,最大应变峰值越来越大;拱顶是加速度振动最激烈的地方,经过加固可以降低拱顶加速度,但效果不明显,在变形不大时底板加速度增加较大,必要时应该采取减震措施,经过加固洞室侧墙加速度普遍有不同程度减小,并且破坏越严重效果越明显,随着比例距离减小,拱顶和侧墙加速度越来越大,尤其当比例距离为5.23 cm/g1/2时,加速度急剧上升。     

北京不同区域明挖基坑地表沉降变形特征研究

基于近年北京地区不同区域大量明挖基坑工程地表沉降实测数据,利用理论计算与回归分析方法,对预测地表沉降的典型曲线“四点折线法”及其模型参数（斜率K及截距b）进行了反演分析,获得了不同区域地质条件下明挖基坑地表沉降预测经验参数;通过对沉降数据及经验参数的统计分析,总结了地表沉降区域变化规律,明确了参数的取值范围,并利用实测数据验证了经验参数的预测精度。结果显示：北京西部区域最大沉降点距离围护结构的水平距离相对中、东部偏大,约为基坑深度的30%,中、东部区域相对较小,均约为基坑深度的26%;地表沉降曲线形态随着区域地质条件不同而不同,四点折线图第一段直线AB的斜率K的绝对值由西向东依次增大,表明东部粉细砂地层比西部砂卵石地层沉降坡度更加明显,第二段直线BC的斜率K的绝对值东部区域比西部区域反而较小,这表明东部区域的沉降影响范围较大;参数bAB绝对值均值由西向东依次增大,表明东部粉质黏土、细沙层相对西部砂卵石地层的桩侧土体沉降值更大,约为最大沉降值的31%,中部区域为21%,西部区域仅为16%。该研究成果将为本地区明挖基坑工程地表变形预测和安全风险控制提供重要的参考依据。     

遗传算法在反演三维地下水流模型参数中的应用

本文以非均质各向同性承压三维非稳定流为理想模型,结合有限元法讨论了用遗传算法反演水文地质参数问题.计算结果表明,本文在简单遗传算法(SGA)的基础上提出的优体克隆+子体优生遗传算法(BCC-YGCD-GA)具有收敛速度快、解的精度高和避免出现早熟等优点.在水资源评价和矿床疏干计算中有广阔的应用前景.     

基于Surpac的贵州水银洞金矿Ia2矿体金品位模型及分形结构特征

以贵州贞丰水银洞金矿Ia2矿体为研究对象,整合二维地质资料,利用Surpac软件建立矿体三维地质模型。以此模型为基础,直观地反映矿体的几何特征,有效把握矿体空间特征,通过与构造蚀变体(SBT)形态相比较,可以看出矿体产出受SBT控制。用距离幂次反比法对品位进行估值,建立块体模型,用不同颜色直观展现矿体品位的分布情况。对Au品位的分形结构特征进行研究,多分数维反映了多次矿化时间的叠加,分数维个数与主要矿石类型相对应。研究成果利于更好地利用地质矿产资料和矿产资源。     

Building a three dimensional sealed geological model to use in numerical stress analysis software: A case study for a dam site

The dam area of the SUOXI hydropower project shows high terrain undulation and complex geological conditions, containing 6 faults and 7 weak inter-beds. A geometric model developed to represent the geology and engineering structures should incorporate the geological realities and should allow suitable mesh generation to perform numerical stress analysis. This is an important precondition to perform rock mass stability analysis of a dam foundation based on a numerical stress analysis software such as FLAC^3D. Using the modeling tools available in FLAC^3D, it is difficult to construct a complex geological model even after performing a large amount of plotting and data analyses. The 3-D geological modeling technique suggested in this paper, named as Sealed Geological Modeling (SGM), is a powerful tool for constructing complex geological models for rock engineering projects that require numerical stress analysis. Applying this technique, first, the geological interfaces are constructed for the dam area of SUOXI hydropower project using various interpolation procedures including geostatistical techniques. Then a unitary wire frame is constructed and the interfaces are connected seamlessly. As the next step, a block tracing technique is used to build a geological model that consists of 130 seamlessly connected blocks. Finally, based on the Advancing Front Technique (AFT), each block is discretized into tetrahedrons and a mesh is generated including 57,661 nodes and 215,471 tetrahedrons which is suitable to perform numerical stress analysis using FLAC^3D.     

A mathematical model for predicting coupled heat and water movement in unsaturated soil

An investigation was conducted to develop a comprehensive moisture model for predicting non-isothermal moisture conditions in soils. An extensive literature review indicated that a model based on the Philip and de Vries equations for non-isothermal moisture movement and heat conduction would give the best results. By using numerical methods, the implicit finite difference approximations to the moisture movement and heat-transfer equations were programmed for computer solution of water content and temperature in the soil with time. Validation studies indicate that the moisture model can be used to predict accurately moisture conditions in the soil. The model was validated by using hydraulic data from laboratory studies conducted on soil columns compacted with AASHO A-3 and AASHO A-4 soil. The application of the moisture model to the study of non-isothermal moisture movement in the field is demonstrated. The influence of parameters such as water table depth, precipitation, and soil hydraulic properties on soil moisture content are shown by use of the moisture model. The model is shown to be applicable to a wide range of boundary conditions and that it predicts the moisture-temperature regime with time in soils utilizing climatic input data.     

露天矿坑岩质边坡浸润线及稳定性研究分析

浸润线是露天矿坑岩质边坡的生命线。针对山东三山岛露天矿坑尾矿库高陡岩质边坡非恒定渗流问题,依据同一条浸润线不同渗流截面的渗流量相等以及不同浸润线同一截面的渗流量差值为库水位的增量建立平衡方程,求解浸润线方程的解,运用Seep/W进行模拟,将理论计算结果与模拟值进行对比,验证浸润线方程的正确性;同时将浸润线方程应用到工程实际中,将库水位监测数据进行曲线拟合,与观测孔数据结合分析浸润线位置的变化,运用ABAQUS流固耦合模型对尾矿库边坡的塑性区和安全系数进行分析。研究结果表明:浸润线方程的解与模拟值最大误差为0.01%,满足实际要求;浸润线观测孔数据与理论计算数据基本吻合,误差最大为0.75m,进一步证明理论可靠性;尾矿库水位的上升增加了塑性区范围,安全系数与尾矿库水位变化曲线为"V"字形,库水位为100m时,安全系数最低为1.06,处于极限平衡状态,同时应将库水位设定在-45m以下,为后期库水位设计提供依据。     

三度体球冠模型重力异常计算方法及其重力归一化总梯度场特征

提出利用铅垂柱体薄片作为面元的面元积分法,计算三度体球冠重力异常的计算公式,用三度体球冠模型模拟三度背斜体,计算了均匀密度球冠模型、非均匀密度储油球冠模型的重力异常。最后通过误差分析,验证了该方法的可行性。采用波数域重力归一化总梯度计算方法,计算了均匀密度球冠模型、非均匀密度储油气球冠模型G^H场,发现似三度背斜体与二度背斜体有相似的G^H场等值线特征,似三度贮油气藏背斜构造的G^H场亦表现出明显的“两高夹一低”的储油典型标志。所以,可以用非均匀密度三度体储油球冠模型模拟三度贮油气藏背斜构造。