Induced seismicity in large-scale mining in the kola peninsula and monitoring to reveal informative precursors   总被引：1，自引：0，他引：1  

N. N. Melnikov  A. A. Kozyrev  V. I. Panin 《Pure and Applied Geophysics》1996,147(2):263-276

Large volumes of rock mass, mined-out and moved within these deposits, resulted in irreversible changes in the geodynamic regime in the upper earth's crust of the adjacent territory. These changes manifest themselves in a more frequent occurrence of such intensive dynamic phenomena as tectonic rock bursts due to fault movement adjacent to the area which is mined-out and man-made earthquakes which sharply decrease mining safety and result in great material losses.To develop the prediction techniques of such phenomena, a monitoring system is created, based on the program of the Kola Complex of geodynamic measuring stations. Most of this system is realized in the region of the Khibiny apatite mines. The system provides regional seismological monitoring, local prediction of seismicity in separate areas of a rock mass and, determination of stress and strain in rock masses, local geophysical monitoring over the state of rocks in a rock mass as well as physical and mathematical modelling of geodynamic processes in the upper earth's crust.The investigations have resulted in the distinguishing of some regularities in manifestations of induced seismicity and tectonic rock bursts and in the determination of strain precursors of intensive seismic events in the Khibiny mines.The mechanism is provided by the induced seismicity which resulted from the anthropogenic impact on the geological medium. A geodynamic monitoring complex is described, which is used to reveal the precursors of powerful seismic eventsin situ, and monitoring results are shown, obtained in the Kola Complex of geodynamic stations. Methods of preventing tectonic rock bursts and induced earthquakes are presented.  相似文献   

Sinkhole subsidence due to mining   总被引：2，自引：2，他引：2  

Kalendra B. Singh  Bharat B. Dhar 《Geotechnical and Geological Engineering》1997,15(4):327-341

This paper reviews the modes of formation of sinkhole subsidence associated with mining activities, drawing on examples in India. Sinkhole (pot-hole) subsidence is an abrupt local depression at the surface which can be hazardous to life and property due to its tendency to occur without warning. Shallow extraction, weak overburden and geological discontinuities are the main factors which cause them. Sinkholes occur due to the failure of a mine roof which migrates through the overlying strata until the failure zone intercepts the unconsolidated overburden. Alternatively they may occur by the creation of cavities in the overburden following the inflow of sand and soil from the overlying weathered and friable strata through faults. Overburden cavities eventually cave in and sinkholes appear at the surface. Sinkholing phenomena can be controlled to some extent by proper design of mining supports and construction of walls to create a barrier around an area prone to sinkholes in bord and pillar workings. Backfilling and grouting can be used to stabilize abandoned underground workings.  相似文献   

适合飞机人工增雨作业天气系统的雷达回波特征分析          下载免费PDF全文

王吉宏  韩江文  胡伟  盛永  杜见微 《气象与环境学报》2006,22(3):1-6

应用2004～2005年沈阳辉山新一代天气雷达资料和常规气象资料,对实施飞机人工增雨作业的天气系统、增雨作业云系及其雷达回波特征进行了归纳和分析,并提出了飞机人工增雨作业条件和作业时机、作业区域等判别方法,为实施飞机人工增雨作业提供科学依据。  相似文献   

平面拓扑模型的多边形矢量更新算法     

崇素文  王庆  王慧青 《测绘科学》2016,41(1):170-174

为了提高土地利用变更图斑的更新效率,文章提出了一种平面拓扑图模型下的多边形矢量数据更新算法:采用平面拓扑图的数据结构,实现多边形几何对象间的线段求交计算,解决多边形间在重点和重边情况下的几何裁剪问题;通过对底图几何对象与变更几何对象之间拓扑关系的判别,不仅能够检测出矢量底图数据中发生变化的几何信息,而且可以减少几何运算的次数,提升矢量数据的更新效率。实验结果表明该算法具有良好的适用性及较高的更新效率。  相似文献   

基于V9I的空间关系映射与操作   总被引：4，自引：0，他引：4  

赵仁亮  陈军  李志林  张学庄 《武汉大学学报(信息科学版)》2000,25(4):318-323

利用V9I模型中目标的边界、内部和Voronoi区域均可量测及易于操作的特点 ,研究建立底层数据结构与空间关系语义层之间的V9I映射机制 ,在Voronoi的动态栅格生成算法的基础上 ,构建空间关系的基本操作。最后 ,以VC 为开发工具并采用面向对象的技术 ,设计了基于V9I的空间关系操作工具原型VTKit ,并给出部分操作实例  相似文献   

Influences of retrogressive erosion of reservoir on sedimentation of its downstream river channel——A case study on Sanmenxia Reservoir and the Lower Yellow River     

Jianguo Chen  Wenhao Zhou  Shanshan Han  Gaohu Sun 《国际泥沙研究》2017,32(3)

Retrogressive erosion, a widespread phenomenon of sediment transport in reservoirs, often impacts on both the reservoir capacity and the sedimentation in the downstream river channel. Based on field data from the Sanmenxia Reservoir and the Lower Yellow River over the past decades, three courses of ret-rogressive erosion with distinctive features were analyzed. The results indicate that retrogressive erosion, especially caused by rapid reduction in the water level till the reservoir is empty, often results in the serious siltation of the lower Yellow River and threatens the safety of the flood control in the Lower Yellow River. Unreasonable operation of the reservoir and incoming hyperconcentrated floods accom-panied by retrogressive erosion also aggravate the siltation of the main channel of the river. However, a reasonable operation mode of the reservoir so named"storing the clear (low sediment concentration) water in the non–flood season, and sluicing the muddy(high sediment concentration) water in the flood season" was found, which might mitigate the deposition in both the reservoir and the Lower Yellow River. This operation mode provides important experience for the design and operation of large reser-voirs in other large rivers carrying huge amounts of sediment.  相似文献   

Freshwater flow to the San Francisco Bay‐Delta estuary over nine decades (Part 2): Change attribution          下载免费PDF全文

Paul H. Hutton  John S. Rath  Sujoy B. Roy 《水文研究》2017,31(14):2516-2529

This paper explains observed trends in freshwater flow to the San Francisco Bay‐Delta estuary as reported in a companion paper (Hutton, Rath, & Roy, 2017 ). We employ a historical hydrologic record spanning nine decades and define a set of idealized flow scenarios to identify drivers of change in delta outflow and consequent salinity regime. Flow changes are measured against a baseline scenario representing 1920‐level land use and water management conditions. Additional scenarios are defined to represent the system absent state and federal water project reservoir and export operations, absent key non‐project reservoir operations, and absent historically‐observed sea level rise. These scenarios, in conjunction with the principle of superposition, are used to ascribe outflow and salinity trends to different anthropogenic and natural causes. We find that project and non‐project water management are attributed similar responsibility for decreasing outflow trends in April and May and consequent increasing spring salinity trends. In contrast, we find that increasing July and August outflow trends (and lagged decreasing salinity trends) are attributed to flow contributions from project water management; these contributions more than fully attenuate impacts associated with non‐project water management.  相似文献   

Microalgal Cultivation Using Animal Production Exhaust Air: Technical and Economic Feasibility     

《洁净——土壤、空气、水》2017,45(4)

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Application of human reliability analysis to repair & maintenance operations on-board ships: The case of HFO purifier overhauling     

《Applied Ocean Research》2019

Maintenance and repair at the operational level is a critical function to comply with the standard of competence for officers in charge of an engineering watch in a manned/unmanned ship engine room. The human factor in ship maintenance especially deals with fulfilling of the required competency about dismantling, inspecting, repairing and reassembling equipment in accordance with manuals and good practice stated in STCW Code, as amended in 2010. This study extends the shipboard operation human reliability analysis (SOHRA) through the marine auxiliary machinery maintenance operations. The approach involves the determined marine-specific error producing conditions (EPC) and generic task type parameters to quantify generic error probability (GEP) values along with the subtasks of the maintenance operation. To acquire the EPC and GEP values, the real case study on heavy fuel oil (HFO) purifier overhauling considers different operating conditions on-board selected five ships in a dry bulk fleet. The case study shows that human error probability (HEP) values of tasks in maintenance operation change in regard to ship operating conditions. Consequently, the study contributes to the marine engineering field in improving the human factor in ship repair and maintenance operations. This approach is further extended by incorporating maintenance 4.0 requirements into ship operating environment to conduct scenario-based task analysis.  相似文献   

Analytical and numerical study of the ground-track resonances of Dawn orbiting Vesta     

N. Delsate 《Planetary and Space Science》2011,59(13):1372-1383

The aim of Dawn mission is the acquisition of data from orbits around two bodies (4) Vesta and (1) Ceres, the two most massive asteroids.Due to the low thrust propulsion, Dawn will slowly cross and transit through ground-track resonances, where the perturbations on Dawn orbit may be significant. In this context, to safety go the Dawn mission from the approach orbit to the lowest science orbit, it is essential to know the properties of the crossed resonances.This paper analytically investigates the properties of the major ground-track resonances (1:1, 1:2, 2:3 and 3:2) appearing for Vesta orbiters: location of the equilibria, aperture of the resonances and period at the stable equilibria. We develop a general method using an averaged Hamiltonian formulation with a spherical harmonic approximation of the gravity field. If the values of the gravity field coefficient change, our method stays correct and applicable. We also discuss the effect of one uncertainty on the C₂₀ and C₂₂ coefficients on the properties of the 1:1 resonance. These results are checked by numerical tests. We determine that the increase of the eccentricity appearing in the 2:3 resonance is due to the C₂₂ and S₂₂ coefficients.Our method can be easily adapted to missions similar to Dawn because, contrarily to the numerical results, the analytical formalism stays the same and is valid for a wide range of physical parameters of the asteroid (namely the shape and the mass) as well as for different spacecraft orbits.Finally we numerically study the probability of the capture in resonance 1:1. Our paper reproduces, explains and supplements the results of Tricarico and Sykes (2010).  相似文献