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Zhang  Yafen  Zhu  Yulong  Yan  Xiaoyu  Li  Shu  Yu  Qijing  Wang  Yidan 《Natural Hazards》2022,110(1):315-323

Explosives are still the cheapest source of breaking rock in the mining or tunnelling operation and can be applied in varying geological conditions. It generates various troubles such as ground vibration, air overpressure, and fly rocks. It is well known that the maximum charge per delay (MCPD) has to be optimum for safe blasting and can be achieved through trial blasts, which is a complicated and costly process. Therefore, it is required to reduce the number of trial blasts. In this study, a total of 18 blasts were conducted in an underground coal mine and were simulated using similar ground conditions using Ansys software. The Peak particle velocity values obtained in the mines and through the models were compared. The error in PPV found between the actual and predicted by simulation is less than 15%. It can help us design the MCPD in rock excavation operations, visualise damages using simulation in Ansys software, and economical compared to field trials.

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基于滑移线场理论(SLFT),提出了一种边坡双折减系数强度折减法失稳判据:当由滑移线场理论计算得到的极限状态下的边坡坡面(简称\  相似文献   

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煤心采取质量是影响煤田地质勘探成果质量的重要因素,本文介绍一种深孔(500~1000m)煤心采取器,其煤心采取率达到90%以上,且能保证煤心样品的代表性。  相似文献   

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Volkhovites are tektite-like glasses of mafic and ultramafic composition discovered in the fluvioglacial drift of the Valdai glaciation (10–60 ka ago) along the right bank of the Volkhov River (59°27′ N, 32°01′ E). Volkhovite particles are small in size (0.1–3.0 mm) and irregular in shape, with various microtektite aerodynamics (globular, droplike, and dumbbell-like forms). They are perfectly preserved, and, thus, postglacial in age. Sporadic volkhovite grains (up to 20 items per 1 kg of loam) were detected over an area 1.0 × 1.5 km2. Some samples from local spots 20 × 30 m2 in size are anomalously enriched, up to 1700 volkhovite grains per 1 kg of loam. Tiny Ti-Fe, Fe, and Cu-Au spherules, particles of quenched glass and cinder, and fragments of the Precambrian and Paleozoic rocks are spatially associated with volkhovites. The suggested cryptomagmatic model assumes that the glass and cinder are pre-Holocene in age, whereas volkhovites were formed in the post-glacial time as a result of the outburst of the slag-stone-melt-mud-gas mixture that ascended from the asthenosphere to the surface. Drops of the melt solidified in the air instantaneously to form tectite-like glasses, and the tuffisite-like agglomerate mixed with the fluvioglacial drift.  相似文献   

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一种可能的新碳酸岩类型:壳源成因碳酸岩   总被引:6,自引:0,他引:6  
本文是对大冶铁矿床接触带"大理岩"及其中分布的"条带状辉石-石榴石大理岩"进行专门研究的阶段性结果.在野外观察到"大理岩"呈岩墙、岩枝和细脉侵入石英闪长岩.根据石准立等的趋势面分析资料,在深部,本矿区"大理岩"与石英闪长岩的接触带总是以突入石英闪长岩内为特征.在"大理岩"与灰岩接触带附近观察到大理岩粒度由于温度冷却快而变细和在"大理岩"中有灰岩残留体."大理岩"本身的方解石粒度中部粗两侧细.本矿区的"大理岩"矿物结晶颗粒比长江中下游许多接触热变质形成的大理岩粗."大理岩"内部浅色大理岩为白色,常具有定向的细条纹构造(可能为流动构造或构造事件引起的线性构造),局部产状变化急剧.在尖山矿段产在"大理岩"中的"条带状辉石-石榴石大理岩",主要含辉石和石榴石条带,其条带走向与"大理岩"岩体延伸方向斜交,且与区内一组断裂构造有关.显微镜观察结果表明,在制备的约65块包裹体切片中均观察到熔融包裹体或流体-熔融包裹体及流体包裹体.包裹体加热实验结果显示,"大理岩"中方解石及"条带状辉石-石榴石大理岩"中的石榴子石和方解石中熔融包裹体接近均一的温度为880~1 055℃,流体-熔融包裹体均一温度为645~740℃."大理岩"及"条带状辉石-石榴石大理岩"的C和O同位素组成与长江中下游的灰岩大致一致,在δ13C-δ18O相关图中的投影点落在沉积碳酸盐范围.电子探针分析表明,在"条带状辉石-石榴石大理岩"的方解石中的一个熔融包裹体为含Si、Ca、Mg、Al和K的混合物(即玻璃)."大理岩"中的圆形固体包裹体成分经电子探针检查为方解石.能谱分析结果表明,"白云质大理岩"的白云石中圆形固体包裹体成分与白云石类似,但与寄主矿物略有区别.在上述初步研究基础上认为,本文所报道的"大理岩"和"条带状辉石-石榴石大理岩"不是由于接触变质引起方解石重结晶的产物,而可能是一种新的碳酸岩类型--壳源成因碳酸岩.  相似文献   

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Moderately sulfidic hydrothermal auriferous quartz-actinolite-magnetite ores in the Ust'-Kara district are found to be economic and their gold content quite stable paragenetically. This unusual paragenesis of gold, in the second stage of the mineralization, represents a radical strengthening of the oxygen regime by which deposition of sulfides was arrested. The auriferous magnetite ores were laid down as fillings of open fissures as well as metasornatically. — V.P . Sokoloff  相似文献   

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A new type of jet from continental Devonian sediments is described. The substrate for gagatization was fragments of Archaeopteris plants, whose burials in sandstone strata are characterized by a kind of spheroidal weathering of organic matter; the material is completely fusainized. This type of jet combines the properties of classical jet and inertinite. The new type of jet was named tsilmanite—after the place of its discovery.  相似文献   

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The finest open fractures (ultramicrofractures) were found from the study of surface density of open fractures in the rocks from the super-deep Uralian borehole SG-4. The high-resolution method of the registration of open fractures in the rocks is described. The typical structures of systems formed by open fractures are shown and their genesis is proposed.  相似文献   

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Stanniferous ores of quartz-sulfide-tourmaline type in a part of the Delbegetey ore field, within the Kalba zone, resemble the Far-Eastern ones by their geological position, but show no resemblance or kinship with any of Kalba ores. Their cassiterite is relatively high in indium but is almost free from tantalum and Miobium, in contrast with the other cassiterites of Kalba. Their mineralization, imposed as it is onto dikes of the second stage, may have connections with the Semeytau volcanic-plutonic complex, but not with the Kalba granites. —V.P. Sokoloff.  相似文献   

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《地学前缘(英文版)》2020,11(4):1163-1174
Impact diamond is one of perspective natural type of superhard carbon materials,forming huge resources sometimes,such as Popigai impact structure counting the largest diamond storage on the Earth.By present,there are two known types of impact diamonds-after-graphitic and after-coal varieties formed from different carbon precursors.Here we present for the first time a new impact diamond type-diamond fossils,named by "karite",formed about 70 Ma from unmetamorphosed organics in the giant Kara impact crater(Pay-Khoy,Russia).A full complex of the diamond fossil characteristics is described proving its nature and phase state.Karite is presented with supernanocrystalline diamond aggregates,nicely preserves tiny cell morphology and relict features of lignin and cellulose.The diamond fossils are spread widely through the Kara impactites,point to possible wider distribution of impact diamonds within large impact occurrences around the world,can be used for impact modeling,astrobiological and material studies.  相似文献   

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一类新型的散粒型土体本构理论   总被引:1,自引:0,他引:1  
岑威钧  朱岳明  王修信 《岩土力学》2007,28(9):1801-1806
详细地介绍了国际上近30才发展起来的具有独特建模思想的一类新型的散粒型土体本构建模理论--亚塑性本构理论。将该理论与经典的弹塑性理论进行比较后发现,亚塑性理论的本构表达式自动隐含了弹塑性理论中相对应的一些基本概念和假定,无需额外引入,因此增加了模型的客观性。以Gudehus-Bauer亚塑性模型为例,分析了模型在临界状态时的本构特征。此外,通过三轴试验和循环剪切试验的亚塑性数值模拟表明,亚塑性本构模型能很好地反映无黏性散粒型土体的非弹性、非线性及剪胀(剪缩)性等主要应力-应变特性。  相似文献   

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由于已知国内的红土型三水铝土矿矿床均为小型,且矿石质量也偏差,多为小规模开采利用,而国外多为大型—特大型矿床,质量也好.笔者长期在境外开展红土型三水铝土矿的资源勘探和资源评价工作.在结合矿山开采的选矿工作和生产氧化铝的拜耳法工艺,对红土型三水铝土矿按照边界品位即是否需要洗矿,提出了全新的分类方法.  相似文献   

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Milashev, V. A., Fiziko-khimicheskiye usloviya obrazovaniya kimberlitov [PHYSICOCHEMICAL CONDITIONS OF FORMATION OF KIMBERLITES]: Edited by V. V. Dolivo- Dobrovol'skiy. NIIGArk MG SSSR, Izd-vo Nedra, Leningrad, 1972. 176 pp., 29 tables, 28 figs., 47 equations, 189 refs. NK 71– 29(49)

Fleyshman, S. M., Sell [MUDFLOWS]: Gidrometeoizciat, Leningrad, 1970. 352 pp., 29 tables, 95 figs., 79 refs. NK 69–44(68).

Savkevich, S. S., Yantar' [AMBER]; lzd-vo Nedra, Leningrad, 1970. 192 pp., 20 tables, 46 figs., 261 refs. NK 70–14(45).

Chernysheva, Z. S., Dolina Volgi i rel'yef Povolzh'ya v apsheronskoye vremya [THE VOLGA VALLEY AND TOPOGRAPHY OF THE AREA IN APSHERONIAN TIME]: Institute of Geography, AN SSSR. Izd-vo Nauka, 1970. 152 pp., 6 tables, 23 figs., 152 refs. NK 70(34)–78.  相似文献   

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