Salt rollers: Structure and kinematics from analogue modelling     

Jean-Pierre Brun  Thomas P.-O. Mauduit 《Marine and Petroleum Geology》2009

Salt rollers are low-amplitude deflections of the upper surface of a salt layer which occur below zones of normal faulting in the overlying sediments. They are widely recognised in association with tilted blocks or listric fault rollover systems. Laboratory experiments on brittle ductile models made of sand and silicone putty are used to study the modes of development, the external shape and the internal structures of these salt rollers. Firstly, flow and strain patterns within décollement zones are described. Finite strain combines layer-perpendicular shortening and layer-parallel shear. Additional flow cells within rollers perturb the laminar flow of the décollement, inducing a passive folding of planar markers. The same type of flow and strain patterns occur in all types of rollers, ranging from those occurring below tilted blocks to those associated with growth faults. Finally, an analysis of roller shapes through the measurement of aspect ratios and asymmetry ratios shows that the shapes of tilted blocks rollers and growth fault rollers—which differ at initiation tend to converge with increasing deformation.  相似文献   

A numerical model of nearshore waves, currents, and sediment transport   总被引：1，自引：0，他引：1  

Pham Thanh Nam  Magnus Larson  Hans Hanson  Le Xuan Hoan   《Coastal Engineering》2009,56(11-12):1084-1096

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Three-dimensional numerical modeling of nearshore circulation   总被引：1，自引：0，他引：1  

SUN Detong 《海洋学报(英文版)》2008,27(Z1):101-118

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Investigations du caractère multifractal des débits maximaux annuels de crue / Investigation of multifractality of maximum annual flood discharges     

《水文科学杂志》2013,58(4)

Abstract

Abstract The multifractal analysis of maximum annual flood discharges at 55 stations of the Tunisian gauging network allows one to associate the various statistical moments of surface discharges of the basins through a scale-invariant law. On this basis, a random cascades model is identified. The scale-invariant law obtained for extreme values represents a theoretical foundation for empirical models proposed since the 1960s which link extreme values, and their associated hazards, with surfaces of drainage areas.  相似文献   

高分辨低漂移的数据采集技术研究     

张俊  邹镇宇  薛兵 《地震地磁观测与研究》2011,32(5):104-108

对于测震观测,大动态和宽频带是当代最主要的技术特征,其关键设备是反馈地震计和24位数据采集器.通过引入调制解调技术来克服由于半导体器件低频噪声和环境温度变化引起的长周期漂移,提高长周期频段数据采集的技术水平.  相似文献   

刘塘坊铁矿1号副井井筒冻结钻孔施工实践          下载免费PDF全文

王兵  汪志祥  董梅  李宏伟 《探矿工程》2011,38(4):53-57

介绍了冻结法施工的原理和特点;简述了刘塘坊铁矿1号副井井筒冻结钻孔的基本情况,分析了本工程施工的难点和采取的技术措施,介绍了施工中需要注意的事项和环节,对本工程进行了施工总结。  相似文献   

地浸砂岩型铀矿致密泥岩齿形复合片钻头的研究与应用   总被引：1，自引：0，他引：1  

要二仓 《地质与勘探》2011,47(2):316-322

针对地浸砂岩型铀矿钻探中致密泥岩钻进效率低的问题,在内蒙古巴音戈壁盆地研究试验了齿形复合片钻头与圆片状复合片钻头,提高了钻进效率.对研磨性较弱,中等硬度致密泥岩,采用Φ104 mm双环式齿形复合片钻头(六组)的钻进效率达到2.60 m/h,比普通复合片钻头提高73%;采用Φ110 mm双环式平底齿形复合片钻头(四组)的...  相似文献   

A numerical model of beach morphological evolution due to waves and currents in the vicinity of coastal structures   总被引：2，自引：0，他引：2  

Pham Thanh Nam  Magnus Larson  Hans Hanson  Le Xuan Hoan 《Coastal Engineering》2011

A numerical model was developed of beach morphological evolution in the vicinity of coastal structures. The model includes five sub-models for random wave transformation, surface roller development, nearshore wave-induced currents, sediment transport, and morphological evolution. The model was validated using high-quality data sets obtained during experiments with a T-head groin and a detached breakwater in the basin of the Large-scale Sediment Transport Facility at the Coastal and Hydraulics Laboratory in Vicksburg, Miss, USA. The simulations showed that the model reproduced well the wave conditions, wave-induced currents, and beach morphological evolution in the vicinity of coastal structures. Both salient and tombolo formation behind a T-head groin and a detached breakwater were simulated with good agreement compared to the measurements.  相似文献   

Analyse multirésolution croisée de pluies et débits de sources karstiquesMultiresolution cross-analysis of rainfall rates and karstic spring runoffs     

David Labat  Rachid Ababou  Alain Mangin 《Comptes Rendus Geoscience》2002,334(8):551-556

In order to quantify the quality of the rainfall/discharge relationship across time-scales, we propose the use of both orthogonal wavelet multiresolution analysis and cross-correlation analysis. By using the two techniques together, it is possible to show, scale-by-scale, the influence of the input to the system (rainfall) on the response (discharge) of the aquifer and also to relate these results to the internal structure of the aquifer and to the degree of organisation of the karst drainage. An application of this method to three Pyrenean karsts is also shown. To cite this article: D. Labat et al., C. R. Geoscience 334 (2002) 551–556.  相似文献   

用相对灰色关联分析法综合评价金刚石钻头          下载免费PDF全文

冯玉国 《探矿工程》1997,(2):36-38

根据ＴＯＰＳＩＳ法原理，提出一种同时考虑“理想方案”和“负理想方案”的金刚石钻头综合评价灰色关联分析法，结合φ６０ｍｍ绳索取心金刚石钻头评价，说明了该方法的具体应用，并与用其它方法评价的结果进行了对比。  相似文献