Positive and negative impacts of longwall mine subsidence on a sandstone aquifer   总被引：3，自引：0，他引：3  

C. J. Booth  E. D. Spande  C. T. Pattee  J. D. Miller  L. P. Bertsch 《Environmental Geology》1998,34(2-3):223-233

 Subsidence due to longwall underground coal mining changes the hydraulic properties, heads, yields, and in some cases the groundwater chemistry of overlying bedrock aquifers. A 7-year study of a sandstone aquifer overlying an active longwall mine in Illinois has supported a comprehensive model of these impacts. Subsidence caused increases in permeability and storativity over the longwall panel. These changes initially caused a major decline in water levels in the sandstone, but the aquifer recovered slightly within a few months and fully within several years after mining. The enhanced hydraulic properties combined with potentiometric recovery resulted in a zone of greater well yield. However, at sites with very poor transmissivity and inadequate recharge pathways, recovery may not occur. Also, at the study site, the physical enhancement was accompanied by a deterioration in groundwater quality from slightly brackish, sodium bicarbonate water to more brackish water with increased sulfate levels. Received: 17 March 1997 · Accepted: 9 September 1997  相似文献   

泥页岩的X射线衍射定向指数与理化性能及井壁稳定的关系   总被引：1，自引：0，他引：1  

沈守文  沈明道  梁大川  张国钊 《沉积学报》1998,(2)

首次提出了泥页岩Ｘ射线衍射定向指数的测定方法,探讨了定向指数与矿物成分,定向指数与泥页岩理化性能（密度、回收率、膨胀率、阳离子交换容量等）的关系。并在定向指数的基础上,提出了综合指数的概念,然后以定向指数和综合指数为主要依据,对坍塌地层泥页岩进行了分类。这对于钻井工程上研究井壁稳定的机理,预防井壁失稳,具有重要的理论意义和实用价值。  相似文献   

Physical properties of the triassic host strata and their relations with gold mineralization in Youjiang Rift, South China     

张景荣  陆建军等 《中国地球化学学报》1998,17(3):226-233

Micro-fine disseminated gold deposits are hosted in the Triassic Baipeng Formation (argillaceous siltstone and arenaceous mudstone)in the Youjiang Rift,South China.Physical properties(grain size,specific surface,porosity and permeability)of the host rocks are studied with respect to ore-fluid cirulation,water-rock reaction and the effective volume from which ore-components could be extracted.On this basis,it is considered that the ore-fluid and oremetals were extracted mainly from the strata and hydrothermal solutions,tending to move to wards low-energy sites,depositing their gold in fault zones at the margins of the basin and in the circle fracture systems around underwater uplifts.The gold deposits resulted from the deepcirculation of hydrothermal solutions,Probably aided by multi-stage superimposition The quantites of ore-fluid necessary to form the deposits were estimated.  相似文献   

煤系岩石工程地质性质指标变异性研究   总被引：2，自引：0，他引：2  

隋旺华  于震平 《煤田地质与勘探》1998,26(5):44-47

对山东金山矿区３煤覆岩及底板工程地质性质类型的物理力学性质指标的变异性进行了研究,用Ｋ－Ｓ法进行的概率分布类型拟合检验表明,各指标基本服从正态分布;另外,还对煤系岩石物理力学性质指标的关联性及各向异性特征进行了初步分析,为煤矿工程地质可靠度研究提供了依据。  相似文献   

关于GIS工具软件可视化设计的几点注记     

秦志远  蔡少华 《测绘学院学报》1998,(1)

文中从实用的角度 ,结合具体实践 ,对 GIS工具型软件可视化设计及实现阶段的基本问题 ,提出了 Visual C++5.0软件环境中有效的解决方法。  相似文献   

土壤风蚀中有关土壤性质因子的研究历史与动向   总被引：10，自引：1，他引：9  

李小雁  李福兴 《中国沙漠》1998,18(1):91-95

国外土壤风蚀中有关土壤性质因子的研究历史可分为四个阶段：第一,定性描述阶段;第二,定量实验研究阶段;第三,运用综合因子建立和完善“通用风蚀方程式”阶段;第四,土壤风蚀土壤亚模型和预测系统的建立和动态研究阶段。国内对土壤风蚀的研究起步较晚,对于不同土类的土壤物理化学性质对风蚀的影响尚没有作深入研究。其历史大致可分为二个阶段：第一,野外观测研究;第二,风蚀的半定量实验研究。目前正由半定量向定量化、标准化、国际化以及动态研究方向发展。  相似文献   

Lake Winnipeg sediment physical properties: interpretation, composite stratigraphic sections and calibration of acoustic reflection profiles     

Kathryn Moran  Catherine A. Jarrett 《Journal of Paleolimnology》1998,19(3):245-253

High resolution sediment physical properties, measured on gravity and piston cores collected during cruises to Lake Winnipeg, include bulk density, acoustic velocity, magnetic susceptibility, shear strength and colour reflectance. The high resolution data are used here to construct complete stratigraphic (composite) sections of Lake Winnipeg sediments from a series of individual, discontinuous cores for the North and South Basins. These composite sections are used to evaluate basin-wide glacial and post-glacial depositional histories and to compare the northern and southern basin histories. In addition, these sections provide a baseline depth reference for interpretation of the biostratigraphy, paleomagnetic record and rock magnetic stratigraphy. Some of the data (density and shear strength) are also be used to estimate sediment stress history for the two major lithostratigraphic units and their variations across the basin.  相似文献   

PHYSICAL PROPERTIES OF THE SYMMETRIC AND ANTISYMMETRIC MOTIONS AND RELATED ENERGY CONVERSION          下载免费PDF全文

Liao Dongxian 《Acta Meteorologica Sinica》1991,5(5):551-563

The physical properties of the symmetric and antisymmetric motions,such as the conservation of the ab-solute angular momentum,the mutual conversions between various forms of energy,have been analysed by usingthe sets of equaticns in p-coordinates controlling the motions in the primitive equation model atmosphere.Theresults show that only the symmetric component of zoral geopotential difference caused by orography and thatof the zonal frictional torque,have contribution to the change of the global angular momentum,and that themutual conversions between various forms of energy,in addition to those similar to the results in the classical case,irclude those associated with the symmetric and antisymmetric motions.  相似文献   

北京地区胀缩性地基土工程特性及其上建筑物破坏原因分析     

李向群 《吉林大学学报(地球科学版)》1991,(4)

本文对北京市通县、南苑、西苑三处的胀缩性地基土进行了物质成分、物理化学性质及微观结构等工程地质特性研究,特别是对影响胀缩土胀缩特性的某些因素作了较深入地研究。并对建筑物变形破坏原因进行了讨论,认为北京市三处胀缩性地基土不均匀收缩变形是导致其上建筑物变形破坏的主要原因。  相似文献   

唐山地震断层破坏及其力学过程的数值模拟   总被引：3，自引：0，他引：3       下载免费PDF全文

王继存  续春荣 《地震地质》1989,11(4):71-76

本文用数值分析方法探讨了地震从孕震到发震的力学过程,以76年的唐山地震为实例,用非线性有限元方法,分析唐山发震断层破坏的力学机制,用增量分析的方法,近似地按时间序列模拟发震断层和周围岩石从孕震到发震的力学过程,并与实测资料进行分析比较  相似文献