偏心跟管钻具钻进的仿真分析          下载免费PDF全文

罗宏保  宋军  赵建勤  黄晓铭 《探矿工程》2010,37(11):6-8

针对偏心跟管钻具工作环境与受力作用复杂的情况,通过建立跟管钻具在地层中钻进的有限元模型,设定各种边界条件及载荷,运用有限元分析软件ANSYS 12.0对跟管钻具的钻进工况进行仿真模拟,分析钻具在钻进时与地层岩土体相互作用下的应力应变情况。根据模拟分析结果能够更清楚地了解钻具钻进时的应力状态,并对钻具的设计、优化起到指导性作用以及为钻具设计结构的合理性提供了理论依据。  相似文献   

Recent studies on surface water–groundwater relationships at hydro‐projects in India using environmental isotopes     

U. Saravana Kumar  Suman Sharma  S.V. Navada 《水文研究》2008,22(23):4543-4553

Environmental isotopes (²H or D, ¹⁸O, ³H), along with geology, hydrochemistry and in situ physicochemical parameters (EC, T, DO, pH) were employed to study surface water (reservoir, lake)–groundwater (spring) relationships at (1) Nagewadi, a minor irrigation project in the State of Maharashtra, Western India; (2) Kanhirapuzha reservoir in the State of Kerala, Southern India and (3) Ghatghar Pumped Storage Hydroelectric Project in the State of Maharashtra, Western India for the purpose of understanding the seepage/leakage and its associated problems. The studies concluded that the springs found downstream of the Nagewadi project originate from the reservoir and not from the abutments or shallow aquifers. The Kanhirapuzha reservoir receives a substantial base‐flow component compared to riverine inputs. The reason for the water‐logging problem at a nearby downstream village during the non‐summer periods is due to the change in the upstream groundwater flow direction under reservoir filling conditions and is not due to reservoir leakage. Most of the springs in the approach tunnel to the underground power house of the Ghatghar Project originate from the lower reservoir and not from the upper reservoir or the overburden rock matrix. The above case studies illustrate the diversity of environmental isotope applications in surface water (reservoir, lake)–groundwater (spring) relationships related to sustainability of hydro‐projects. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

Some numerical issues using element‐free Galerkin mesh‐less method for coupled hydro‐mechanical problems     

Mohammad Norouz Oliaei  Kenichi Soga  Ali Pak 《国际地质力学数值与分析法杂志》2009,33(7):915-938

A new formulation of the element‐free Galerkin (EFG) method is developed for solving coupled hydro‐mechanical problems. The numerical approach is based on solving the two governing partial differential equations of equilibrium and continuity of pore water simultaneously. Spatial variables in the weak form, i.e. displacement increment and pore water pressure increment, are discretized using the same EFG shape functions. An incremental constrained Galerkin weak form is used to create the discrete system equations and a fully implicit scheme is used for discretization in the time domain. Implementation of essential boundary conditions is based on a penalty method. Numerical stability of the developed formulation is examined in order to achieve appropriate accuracy of the EFG solution for coupled hydro‐mechanical problems. Examples are studied and compared with closed‐form or finite element method solutions to demonstrate the validity of the developed model and its capabilities. The results indicate that the EFG method is capable of handling coupled problems in saturated porous media and can predict well both the soil deformation and variation of pore water pressure over time. Some guidelines are proposed to guarantee the accuracy of the EFG solution for coupled hydro‐mechanical problems. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

A comparison of variational formats for porous media subjected to dynamic loading     

B. Lenhof  F. Larsson  K. Runesson 《国际地质力学数值与分析法杂志》2011,35(7):807-823

This paper presents a comparison of two variational formats for fully saturated porous media subjected to dynamic loading, whereby the general situation of relative fluid acceleration is considered: (1) the classical three‐field ( u , p, w )‐format and (2) a novel two‐field ( u , p)‐format, where the seepage velocity w is a spatially ‘local’ field whose treatment resembles that of internal variables in material models. The limited numerical comparison shows that the ( u , p)‐format competes well with the ( u , p, w )‐format. Indeed, it is consistent with the general acceleration modeling in the full range of permeabilities. Moreover, in the low permeability regime (where the magnitude of w is insignificant), the new format reflects the situation pertinent to ‘added‐mass’ and is more efficient than the classical ( u , p, w )‐format. Finally, the ( u , p)‐formatcan conveniently be implemented in existing FE‐codes based on the ‘added mass’ formulation. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

潜孔锤跟套管技术在挡土墙加固工程中的应用     

计胜利  张勇  张育柏 《世界地质》2001,20(2):206-208

由于地层较为复杂，采用普通潜孔锤钻进方法难以成孔，实践证明，风动潜孔锤跟管进技术是破碎复杂地层中钻进成孔最为有效的方法。下锚结束后，应及时将套管从孔中拔出，单纯依靠钻机自身提引力很难实现，采用潜孔锤向上反击起拔套管，既保护了钻机又节省了起拔套管的时间。  相似文献   

冲击回转碎岩机理试验研究   总被引：2，自引：0，他引：2       下载免费PDF全文

常玉军  殷琨 《探矿工程》2001,(4):62-64

在模拟孔底冲击回转钻进条件的试验台上，对岩石的冲击回转碎岩机理进行了试验研究，提出了大直径潜孔钻头的合理布齿及钻进参数选择依据。  相似文献   

The effect of surface texture on the determination of the surface hardness of rock using the schmidt hammer     

R. B. G. Williams  D. A. Robinson 《地球表面变化过程与地形》1983,8(3):289-292

The Schmidt hammer is employed by geomorphologists as a convenient field instrument for measuring the hardness of rock surfaces. Field trials indicate that the readings obtained are a function of not only the hardness of the surfaces but also their texture. Smooth planar surfaces give much higher readings than rough or irregular surfaces. This makes interpretation of the results particularly difficult when the hammer is used to measure the hardness of natural rock surfaces that have been roughened by weathering.  相似文献   

西部特殊景观区钻探取样技术展示     

王达 《探矿工程》2005,32(1):1-5

针对西部特殊景观区海拔高、地势险峻、地形地质条件复杂、自然条件恶劣、地理位置偏远、交通不便等问题，我国科研人员经过多年努力，开发并完善了一批适合于特殊景观区的钻探技术——空气组合钻探技术、水文水井泡沫增压钻探技术、复杂地层钻探取样新技术、液动潜孔锤钻进技术、特殊地层取样钻机及钻探工艺、节水钻探新技术、新疆吐鲁番铀矿勘探及罗布泊环境科学钻探用取样工艺、西部特殊景观区资源勘查及重大建设工程中地质灾害监测和防治新技术、存储式多点连续测斜仪等，介绍了各项新技术的原理、研究进展及取得的成果。  相似文献   

The influence of rock resistance on coastal morphology around Lord Howe Island,southwest Pacific     

M. E. Dickson  D. M. Kennedy  C. D. Woodroffe 《地球表面变化过程与地形》2004,29(5):629-643

An Erratum has been published for this article in Earth Surface Processes and Landforms 27(7) 2004, 931. Lord Howe Island, in the northern Tasman Sea, is a remnant of a much larger Late Miocene basaltic shield volcano. Much of the island's coastline is exposed to waves that have unlimited fetch, but a marked contrast is provided by a fringing coral reef and lagoon that very effectively attenuate wave energy along a portion of the western coastline. The geology of the island is varied, with hard and resistant basalt lavas, breccias and tuffs of intermediate resistance, and highly erodible eolianites. This variability provides an excellent opportunity to examine the in?uence of rock resistance on the development of the spectacular rock coast landforms that occur around the island. The hardness of rocks and the extent of weathering around the coastline were assessed using a Schmidt hammer, and statistical analysis was undertaken to remove outlying values. On all but one occasion, higher mean rebound values were returned from fresh surfaces than weathered surfaces, but only half of these differences were statistically signi?cant. Shore platforms with two distinct levels are juxtaposed along two stretches of coastline and Schmidt hammer results lend support to hypotheses that the raised surfaces may be inherited features. Relative rock resistance was assessed through a combination of Schmidt hammer data and measurements of joint density, and constrained on the basis of morphological data. This approach formed a basis for examining threshold conditions for sea‐cliff erosion at Lord Howe Island in the context of the distribution of resistant plunging cliffs and erosional shore platforms. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

潜孔锤在鄂西找水勘察施工中的应用效果          下载免费PDF全文

黄云龙  申晓彬 《探矿工程》2005,32(7):56-57

为了尽快解决湖北恩施自治州部分乡镇缺水问题，我院连续4年投入少量找水勘察任务，使用空气潜孔锤钻进，取代传统岩心钻探方法，加快了勘察施工速度，积累了经验，为今后使用潜孔锤在基岩地层找水成井施工打下了基础。  相似文献