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Jurassic granitoid dike in Luodian, Guizhou Province: discovery and geological significance

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Acta Geochimica 2019年第1期38卷 159-172页

作者： Mingjin Zhu Aiguo Nie Yazhou Tian Xinsong Wang Jun Sun Guizhou University Guizhou Institute of Technology State Key Laboratory of Ore Deposit Geochemistry Institute of Geochemistry Chinese Academy of Sciences

In this paper, the Jurassic granitoid dike that intrudes into Permian diabase was reported in Luokun,Luodian County, south Guizhou. Zircon LA-ICP-MS U–Pb dating of the granitoid dike yielded an age of 164.3 ± 2.4 Ma with the e Hf(t) range from + 7.8 to + 12.1. The high contents of SiO_2(65.2%–66.8%) and total alkali(Na_2O + K_2O: 9.01%–9.95%), and low contents of Mg, Fe, Ca, P and Ti show the characteristics of alkali-rich granite. The total contents of rare earth elements range from 289.90 to 394.23 ppm. The Rb, Ba, K, Th, U and other LILE, Ta, Sr, P, Ti are enriched, and heavy rare earth elements are depleted. Petrogeochemical characteristics show that the dike was derived from a partial melting of newly-grown basaltic crust, and contaminated by crustal materials before experiencing strong fractional crystallization. The dike was formed in the intraplate post-orogenic extension stage and indicates that parental magma rose to the shallow crust through a fault. This provides new evidence of tectonic and mantle-crust magmatic activities and may contribute to regional Au mineralization in southern Guizhou and neighboring areas.

关键词： Jurassic granitoid dike Geochemical characteristics Geochronology Luodian Guizhou province

Simulation of flow pattern at rectangular lateral intake with different dike and submerged vane scenarios

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Water Science and Engineering 2017年第3期10卷 246-255页

作者： Hojat Karami Saeed Farzin Mohammad Tavakol Sadrabadi Hasan Moazeni Faculty of Civil Engineering Semnan University School of Water Sciences Engineering Shahid Chamran University of Ahvaz

A comprehensive understanding of the sediment behavior at the entrance of diversion channels requires complete knowledge of threedimensional(3 D) flow behavior around such structures. dikes and submerged vanes are typical structures used to control sediment entrainment in the diversion channel. In this study, a 3 D computational fluid dynamic(CFD) code was calibrated with experimental data and used to evaluate flow patterns, the diversion ratio of discharge, the strength of secondary flow, and dimensions of the vortex inside the channel in various dike and submerged vane installation scenarios. Results show that the diversion ratio of discharge in the diversion channel is dependent on the width of the flow separation plate in the main channel. A dike perpendicular to the flow with a narrowing ratio of 0.20 doubles the ratio of diverted discharge in addition to reducing suspended sediment input to the basin, compared with a no-dike situation, by creating the outer arch conditions. A further increase in the narrowing ratio decreases the diverted discharge. In addition, increasing the longitudinal distance between consecutive vanes(Ls) increases the velocity gradient between the vanes and leads to a more severe erosion of the bed, near the vanes.

关键词： Three-dimensional simulation Computational fluid dynamics Submerged vanes dike Side and vortex flow

Stability of the Guiding dike in Yangtze Estuary Under the Wave Load

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China Ocean Engineering 2005年第4期19卷 659-670页

作者：闫澍旺刘润范期锦谢世楞 School of Civil Engineering Tianjin University Tianjin300072 China Yangtze Estuary Waterway Construction Co. Ltd. Shanghai 200003China The First Waterway Design Institute Tianjin300222China

During the construction of the guiding dike in the Yangtze Estuary, some of the caisson structures sank into the soil for 1 -5 m or slid about 20 m away from the original place when a strong storm attacked this area. Dynamic triaxial tests were carried out to simulate the behavior of foundation soils under wave loading. The test results show that the excessive settlement and lateral movement of the caissons are due to the weakening of the soft clay strength during the strong storm. The test results also show that the ability of the soft clay to resist the wave force will be greatly increased when the soft soil samples are suitably improved. Based on the test results, an improvement method combining vertical drains with surcharge loading was proposed to strengthen the foundation soil. On the improved soil foundation, the dike has been reconstructed and undergone several strong storms without any damage. A finite element approach has been developed for analyzing the settlement and stability of the dike under the action of strong storm.

关键词： soft clay strength weakening dike dynamic triaxial test FE analysis

Design Methods for Geotextile Tubes Application in dike Construction

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China Ocean Engineering 2008年第3期22卷 445-453页

作者：闫玥闫澍旺邱长林郑刚 School of Civil Engineering Tianjin University

The technique of geotextile tubes used to construct dikes for land reclamation has been widely used. The tubes are usually filled with slun＇y of soil, such as sand, silt or clay. The tensile stress developed in the geotextile during filling the tube is the dominant factor for construction of a safe dike. The existing design methods are good for designing sausage shaped tubes and can not be directly applied for designing fiat tubes, which are commonly used in dike construction. This paper presents a procedure that can detenmine the relatiorrship among the tube size, the pumping pressure, the unit weight of the slurry, and the tensile stress developed in the geotextile during the tube filing. When the tubes are piling up to form the dike, the tubes in the bottom will sustain the load from the weight of the upper ones. A procedure is also developed to calculate the changes of the mechanical and geometrical behavior of the tubes under the load with a similar method. All these approaches have been programmed, which can help dike designers to select the suitable geotextile and determine the profile of the dike.

关键词： geotextile tube design dike inflated tensile force

Validation of an operational forecasting system of sea dike risk in the southern Zhejiang Province, South China

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Journal of Oceanology and Limnology 2019年第6期37卷 1929-1940页

作者： LI Tao WANG Fangdong HOU Jingming CHE Zhumei DONG Jianxi National Marine Environmental Forecasting Center Beijing 100081China Key Laboratory of Research on Marine Hazards Forecasting of State Oceanic Administration Beijing 100081China Beijing Space Flight Control Center Beijing 100094China Marine Monitoring and Forecasting Center of Zhejiang Province Hangzhou 310007China

In this study,an operational forecasting system of sea dike risk in the southern Zhejiang Province,South China was developed based on a coupled storm-surge and wave *** forecasting system is important because of the high cost of storm-surge damage and the need for rapid emergency planning.A comparison with astronomical tides in 2016 and the validation of storm surges and high water marks of 20 typhoons verified that the forecast system has a good simulation *** system can forecast relatively realistic water levels and wave heights as shown under the parametric atmospheric forces simulated in a case study;the sea dikes in credible high risk were mainly located in the estuaries,rivers,and around the islands in the southern ***,the forecast system is applicable in the southern Zhejiang with a support to the effective prevention from typhoon storm-surge damage.

关键词： storm surge sea dike operational forecast southern Zhejiang Province risk calculation

Application of Geotextile Bag Dehydrated Soil to dike Construction

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Transactions of Tianjin University 2004年第4期10卷 297-303页

作者：朱平闫澍旺刘润 Geotechnical Research Institute Tianjin University Tianjin 300072 China

Using geotextile bag dehydrated soil to construct dikes for land reclamation to substitute conventional straw bags is an urgent need in Tianjin New Harbor, China. This paper introduces the method to build a dike for hydraulic filling. The soil for filling the geotextile bags was tested in wave trench; the stress developed during construction was calculated by establishing a numerical model and compared with the tensile strength of the geotextile; the stability and settlement of the dike were estimated by performing centrifuge tests. Through this study, the following information was obtained: 1) The cohesionless silt with plasticity index less than 10 is suitable for filling the geotextile bags. The geotextile bag dehydrated soil consolidated very quickly even under the action of wave force. 2) A numerical model was devised to find the limit injection height and to calculate the tensile stress developed in the geotextile bags when they were piled up to form the dike. The calculated stress was compared with the strength of the geotextile, showing that the design is reasonably safe. 3) Centrifuge test results show that the designed dike will be stable and the settlement of dike will be less than the design requirement.

关键词： geotextile bag dehydrated soil silt dike reclamation centrifuge test

Geochronology, geochemistry and tectonic implications of Xiongshan diabasic dike swarm, northern Fujian

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Science China Earth Sciences 1997年第4期40卷 411-417页

作者：任胜利李继亮周新华孙敏 Department of Earth Science China University of Geosciences Beijing 100083 China Institute of Geology Chinese Academy of Sciences Beijing 100029 China Department of Earth Sciences University of Hong Kong Hong Kong

Sm/Nd isotopic age determination showed that Xiongshan dike swarm was at 585.7 Ma±30 Ma. The trace element geochemistry and Sr/Nd/Pb isotope geochemistry studies indicate that the dike swarm was products of back-arc basin spreading ridge and the magma originated from the depleted mantle region which was metasomatized by LTLE-rich liquids/melts derived from subduction slab.

关键词： dike swarm petrochemistry Sinian-early Paleozoic back-arc basin northern Fijian

Discovery and significance of Xucun late Proterozoic composite dike swarm in southern Anhui Province

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Chinese Science Bulletin 1997年第4期42卷 328-330页

作者： Tang, HF Zhou, XM Zhi, LG Department of Earth Sciences Nanjing University Nanjing China No. 332 Geological Party Bureau of Geology and Mineral Resources of Anhui Province Huangshan China

GEOLOGICALLY, southern Anhui Province, East China, is a part of late Proterozoic collision orogens of the southeast margin of the Yangtze Block. In this region the development of late Proterozoic Fuchuan ophiolite suite and collision granitoids of Xiuning, Xucun and Shexian mark the existence of the intensely tectonic-magmatic events. Recently discovered Xucun

关键词： late Proterozoic composite dike swarm southern Anhui Province.

dike FORMATION WITH SUBMERGED VANE

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International Journal of Sediment Research 2006年第3期21卷 200-208页

作者： Umesh P. GUPTA C. S. P. OJHA Nayan SHARMA Morphology Directorate Central Water Commission New Delhi India Civil Engg. Dept. Indian Institute of Technology Roorkee India Prof. WRD&M Dept. Indian Institute of Technology Roorkee India Prof.

Submerged vanes are submerged foils constructed in a river at an angle of attack to induce horizontal circulation in the downstream flow. The initial height of vanes is 0.2 – 0.4 times the local water depth (d) at the design stage. Its length expressed as a multiple of the height to length ratio (H/L) normally is 0.25 to 0.5. With the use of a submerged vane in straight channels, dikes (heaps of sediment) were formed downstream. At an optimal angle of attack of 40o and at a Froude number of 0.25, the formation of the dike starts at some distance from the trailing edge of the rectangular and trapezoidal submerged vanes with a collar. A significant scour hole results at the trailing edge of a vane with a collar. A typical dike formed along the vane on the suction side with a symmetric bell-shaped profile. The dike formation phenomenon triggered by a vane close to the bank-line at a flow with a relatively higher Froude number, such as 0.25, does not seem to follow a straight alignment, but has a sort of curvilinear shape bent towards the suction side. The dike formation process for a flow with a smaller Froude number, such as 0.13, is observed to not be appreciable. With the same installation height of H, a vane without a collar was dislodged by the flow at a Froude number of 0.25, whereas it was stable at a Froude number of 0.13.

关键词： Rectangular and trapezoidal submerged vanes Circulation Collar dike Scour Froude number