泥岩层状破碎带特大涌水处理方法探索与实践     

万翔鸿  张迪迪  张磊 《探矿工程》2010,37(6):65-66,70

泥岩地质条件一般较差,在这种基础上修建大型水利工程,基础处理难度较大。哈达山水利枢纽工程坝基为近水平发育的泥岩,坝基深处发育层状破碎带,严重影响坝基的稳定安全。通过分析这种地层中的涌水的渗透通道,采取了一系列注浆处理措施。这种处理方法既节约成本,又保证施工质量。结合本工程发电厂房集水井特大突水及整个P7破碎带处理方法,总结针对泥岩地层中特大涌水处理的思路和方法。  相似文献   

低密度水包油钻井液在中原油田水平井的应用          下载免费PDF全文

郑德荣  孙善刚  李国保  黄宁  史沛谦 《探矿工程》2010,37(9):15-18

根据低压力储层水平井钻井油气层保护要求,通过室内研究形成了密度在0.89~0.99 g/cm3之间可调,具有良好乳化稳定性和流变性,防塌能力强的低密度水包油钻井液配方。在达平1井等井的现场应用中,水包油钻井液性能稳定,易于维护调节,钻井施工安全快速,能够满足低压水平井近平衡、欠平衡钻井和地质要求,保护储层作用明显,收到了良好的应用效果。  相似文献   

MAIC-2, a latitudinal model for the Martian surface temperature, atmospheric water transport and surface glaciation     

R. Greve  B. Grieger 《Planetary and Space Science》2010,58(6):931-940

The Mars Atmosphere-Ice Coupler MAIC-2 is a simple, latitudinal model, which consists of a set of parameterisations for the surface temperature, the atmospheric water transport and the surface mass balance (condensation minus evaporation) of water ice. It is driven directly by the orbital parameters obliquity, eccentricity and solar longitude (L_s) of perihelion. Surface temperature is described by the Local Insolation Temperature (LIT) scheme, which uses a daily and latitude-dependent radiation balance. The evaporation rate of water is calculated by an expression for free convection, driven by density differences between water vapor and ambient air, the condensation rate follows from the assumption that any water vapour which exceeds the local saturation pressure condenses instantly, and atmospheric transport of water vapour is approximated by instantaneous mixing. Glacial flow of ice deposits is neglected. Simulations with constant orbital parameters show that low obliquities favour deposition of ice in high latitudes and vice versa. A transient scenario driven by a computed history of orbital parameters over the last 10 million years produces essentially monotonically growing polar ice deposits during the most recent 4 million years, and a very good agreement with the observed present-day polar layered deposits. The thick polar deposits sometimes continue in thin ice deposits which extend far into the mid latitudes, which confirms the idea of “ice ages” at high obliquity.  相似文献   

高速铁路运行引发场地振动的空沟隔振分析          下载免费PDF全文

肖慧娟  董尘 《地震工程学报》2021,43(6):1419-1428

为研究高速列车作用下,层状地基中空沟对场地振动的隔振效果,基于车辆-轨道耦合动力学理论及有限元法,对建立完善高速车辆-无砟轨道-地基耦合系统动力学模型进行仿真计算,分析设置空沟对场地振动的影响,并探讨了空沟的深度、位置、宽度以及列车速度的影响。结果表明：设置空沟加强了沟前场地的振动,但可使空沟后方地基的竖向和水平振动水平大幅减小,但在特定位置存在振动放大区,引起隔振效果减弱;过浅或过深的空沟均不能达到最优隔振效果;对于在线路旁需要特殊隔振的场地,存在一个适用于其本身的空沟最佳位置;空沟的宽度对隔振效果无明显影响;空沟对更高速度运行列车引起场地竖向和横向振动的隔振效果更明显。  相似文献   

小角法在水平位移监测中的应用分析     

苏京平 《上海国土资源》2010,(2):50-53

目前广泛进行的建筑变形监测中,一些监测人员利用小角法测量水平位移时不能正确把握测量的关键环节,导致监测失误甚至酿成质量事故的现象屡有发生。本文对小角法应用中的关键环节进行技术分析,提出个人的观点,并以实例进行说明。  相似文献   

Uniform asymptotic Green's functions for efficient modeling of cracks in elastic layers with relative shear deformation controlled by linear springs     

Anthony P. Peirce  Hongren Gu  Eduard Siebrits 《国际地质力学数值与分析法杂志》2009,33(3):285-308

We present a uniform asymptotic solution (UAS) for a displacement discontinuity (DD) that lies within the middle layer of a three‐layer elastic medium in which relative shear deformation between parallel interfaces is controlled by linear springs. The DD is assumed to be normal to the two interfaces between the elastic media. Using the Fourier transform method we construct a leading term in the asymptotic expansion for the spectral coefficient functions for a DD in a three‐layer‐spring medium. Although a closed‐form solution will require a solution in terms of an infinite series, we demonstrate how this UAS can be used to construct highly efficient and accurate solutions even in the case in which the DD actually touches the interface. We compare the results using the Green's function UAS solution for a crack crossing a soft interface with results obtained using a multi‐layer boundary element method. We also present results from an implementation of the UAS Green's function approach in a pseudo‐3D hydraulic fracturing simulator to analyze the effect of interface shear deformation on the fracture propagation process. These results are compared with field measurements. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

Growth of new economic sectors in second-tier extended cities in the Changjiang River Delta     

Chen Wen  Sun Wei  Xiang Jun-bo 《中国地理科学(英文版)》2004,14(4):296-303

The second-tier extended metropolises in the Changjiang (Yangtze) River Delta, including Suzhou, Wuxi and Changzhou near Shanghai, are becoming the most active and new innovative industrial agglomerating areas. Manufacturing industries in these second-tier cities have been in rapid growth due to increasing foreign investment. Nevertheless, the economic prospect of these cities is still constrained by a lack of local R&D capacity and production services, which are mainly dependent upon Shanghai. This paper analyses the impact of globalization on the new economic sectors in these cities, the change of industrial structure, the limitation of urban development and the problem of sustainability. Then, the paper analyses the conditions for the high-tech industry and production services in these areas. Also, it applies the industrial organization theory to these cities and examines how these cities can cooperate with each other in terms of horizontal linkages. Finally, the paper gives the future growth prospects in high-tech industry and production services. Foundation item: Under the auspices of the National Natural Science Foundation of China (No. 40371031) Biography: CHEN Wen (1967–), female, a native of Ningde of Fujian Province, professor, specialized in urban economic and urban geography. E-mail: wchen@niglas.ac.cn  相似文献   

A pulsational approach to near-infrared and visual magnitudes of RR Lyr stars     

G. Bono  F. Caputo  V. Castellani  M. Marconi  J. Storm  S. Degl'Innocenti 《Monthly notices of the Royal Astronomical Society》2003,344(4):1097-1106

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Distant field blue horizontal branch stars and the mass of the Galaxy – I. Classification of halo A-type stars     

L. Clewley  S. J. Warren  P. C. Hewett  John E. Norris  R. C. Peterson  N. W. Evans 《Monthly notices of the Royal Astronomical Society》2002,337(1):87-97

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崔笃信  王庆良  王文萍  胡亚轩 《大地测量与地球动力学》2007,27(1):24-30

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