共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
3.
The Rapid Inversion of 3-D Potential Field and Program Design 总被引:1,自引:0,他引:1
The application of three-dimensional inversion of gravity and magnetic fields is very important not only in geophysical researches, but also in the study of geological structures. A formula of potential field in frequency-domain, developed by Parker in 1973, can be used as a rapid and effective algorithm in gravity and magnetic inversion. The technique has been improved then by Oldenburg, Sprenke, Feng and others.In addition to a brief introduction of Parker's algorithm and its applications, this paper includes the following five parts: basic computational techniques, inversion of single layer, convergence and constraints, simultaneous inversion for density and topography as well as inversion of multilayers. The authors present relevant practical iterative formulas and its varieties when density distribution varies with depth in linear or exponential relation. In order to maintain computation stability and speed up iteration convergence, some approaches are taken in the program design, for instance shifting lower interface of the studied layer, inverting corrections of topography, reducing grid boundary effects and utilizing low-pass filter. With the consideration of the nonuniqueness of the inversion, a method of using seismic data to constrain the range ofpossible models is discussed. It is pointed out that the density variation generates less effects than those of topography on the spectrum of gravity anomaly in second order. Therefore density contrast and topography can be inverted simultaneously by an alternative weighting iteration. By analogy, the inversion of multilayer model can be done in the above procedure. An approach of model decomposition is useful in the computation of multilayer model. The techniques discussed in the present paper for gravitational field are also valid for magnetic field. 相似文献
4.
5.
D. Thornton S. S. Kanchibotla I. Brunton 《Fragblast: International Journal for Blasting and Fragmentation》2002,6(2):169-188
Most blast fragmentation models assume the rock mass properties. explosive properties and blast design variables to be constants and uniformly distributed within a blast. However, in reality all these input variables vary within a blast resulting in variation in the resulting fragmentation size distribution. A stochastic modelling approach is introduced in this paper to quantify this variation. This technique takes the input variables as statistical distributions rather than constants and through several thousand iterations, generates a statistical representation of the expected fragmentation resulting from a poduction blast. A case study of three production blasts from a large open pit mine are presented and the modelled fragmentation 'envelope' shows good agreement with the fragmentation 'envelope' estimated from Split image analysis. The various blast-related parameters influence different parts of the fragmentation distribution, e.g., rock strength and explosive velocity of detonation have most impact on the fines. The technique is used to identify the parameters that have the greatest influence on various size fractions. Such an analysis will be useful to direct resources to efficiently minimise the variation. 相似文献
6.
7.
8.
介绍了MD-50型钻机液压系统的设计原理和主要液压元件的选择依据,并通过对设计和实践的总结,谈了作者在全液压钻机液压系统设计中的一些体会。 相似文献
9.
10.
岩心定向检测仪的设计与实验研究 总被引:2,自引:0,他引:2
本文设计了一种基于机械法的岩心定向仪。机械部分采用三把刻刀在岩心上刻标记线,作为岩心方位的基准线;电路部分以ATmega8单片机为控制核心,用HMR3300传感器随钻测得靠近岩心管的仪器仓的俯仰角和侧滚角,间接测得岩心的俯仰角和侧滚角,存于U盘。介绍了HMR3300与刻刀的安装关系,推导了高边工具面角的计算方法,并通过实验找到HMR3300不同安装方式下,高边工具面角真值φ'与计算值φ间的关系,岩心方位角与测井得到的孔斜方位角ψ和高边工具面角真值φ'的关系,依此PC机编程计算得岩心方位角。实验表明,在井眼顶角大于1°时,其测量平均误差能够控制在3°以内,并可稳定工作,基本满足工程要求。 相似文献
11.
12.
TK-3液压立轴式钻机 总被引:2,自引:0,他引:2
继TK-1、TK-4、TK-5钻机之后,我们又研制成功了 TK-3钻机。这种钻机保留了原 TK 系列钻机的优点,克服了 TK 系列钻机的不足,在试验中获得较好的评价。 相似文献
13.
14.
15.
在三维地震勘探中,在山地大型障碍区布设观测系统,为了避免因地表障碍物使地震反射剖面出现间断,需要动态调整观测系统设计,跨越大型障碍物(水库,矿区等),以确保面元属性均匀,最佳压制噪声,以获得好的反射资料。在参与和研究野外实际过障碍观测系统的基础上,提出一套从物理点优化调整到辅助检测的方法。其基本思路是:利用高精度数字卫星照片和地震测量成果,对设计的规则观测系统进行反复调整,尽量避开障碍物,在计算出调整后的覆盖次数、炮检距,以及方位角分布情况后,设计出适用于障碍区的动态观测系统。这里总结了几条设计原则,并给出了相应的调整方法和辅助检测手段。通过合理动态调整炮点和检波点的位置,成功地解决了穿越大型障碍区时有效接收和安全激发的问题,确保了面元内覆盖次数、炮检距、方位角等属性的均匀,在W探区三维资料采集应用中取得了理想的效果。 相似文献
16.
17.
18.
19.
20.
Blast Design Using Measurement While Drilling Parameters 总被引:1,自引:0,他引:1
J. B. Segui M. Higgins 《Fragblast: International Journal for Blasting and Fragmentation》2002,6(3):287-299
Measurement while drilling (MWD) techniques can provide a useful tool to aid drill and blast engineers in open cut mining. By avoiding time consuming tasks such as scan-lines and rock sample collection for laboratory tests, MWD techniques can not only save time but also improve the reliability of the blast design by providing the drill and blast engineer with the information specially tailored for use. While most mines use a standard blast pattern and charge per blasthole, based on a single rock factor for the entire bench or blast region, information derived from the MWD parameters can improve the blast design by providing more accurate rock properties for each individual blasthole. From this, decisions can be made on the most appropriate type and amount of explosive charge to place in a per blasthole or to optimise the inter-hole timing detonation time of different decks and blastholes. Where real-time calculations are feasible, the system could extend the present blast design even be used to determine the placement of subsequent holes towards a more appropriate blasthole pattern design like asymmetrical blasting. 相似文献