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1.
在系统开展海洋区域地质调查的过程中，荷兰广泛使用了各种地球物理调查方法，并在方法选用、测线部署、资料处理和图件编制等方面有许多独到之处；对中荷两国的做法进行了系统的比较；对今后在我国海洋区域地质调查中如何开展地球物理调查工作提出了建议。 相似文献
2.
Technical difficulties associated with excavation works in tectonized geological settings are frequent. They comprise instantaneous
and/or delayed convergence, sudden collapse of gallery roof and/or walls, outpouring of fault-filling materials and water
inflows. These phenomena have a negative impact on construction sites and their safety. In order to optimize project success,
preliminary studies on the reliability of rock material found on site are needed. This implies in situ investigations (surface
mapping, prospective drilling, waterflow survey, etc.) as well as laboratory investigations on rock samples (permeability
determination, moisture and water content, mineralogy, petrography, geochemistry, mechanical deformation tests, etc.). A set
of multiple parameters are then recorded which permit better insight on site conditions and probable behavior during excavation.
Because rock formations are by nature heterogeneous, many uncertainties remain when extrapolating large-scale behavior of
the rock mass from analyses of samples order of magnitudes smaller. Indirect large-scale field investigations (e.g. geophysical
prospecting) could help to better constrain the relationships between lithologies at depth. At a much smaller scale, indirect
analytical methods are becoming more widely used for material investigations. We discuss in this paper X-ray computed tomography
(XRCT) and neutron tomography (NT), showing promising results for 3D petrographical investigations of the internal structure
of opaque materials. Both techniques record contrasts inside a sample, which can be interpreted and quantified in terms of
heterogeneity. This approach has the advantage of combining genetic parameters (physico-chemical rock composition) with geometric
parameters resulting from alteration or deformation processes (texture and structure). A critical analysis of such 3D analyses
together with the results of mechanical tests could improve predictions of short- and long-term behavior of a rock unit. Indirect
methods have the advantage of being non-destructive. However, as it is the case with large-scale geophysical surveying, XRCT
and NT are affected by several error factors inherent to the interaction of a radiation modality (X-ray or neutron beam) with
the atomic structure of the investigated materials. Recorded signals are therefore in particular cases not artifact-free and
need to be corrected in a subsequent stage of data processing. 相似文献
3.
浅层地震技术在隧道勘察中的应用 总被引：2，自引：0，他引：2
论述了在深圳市东部沿海高速公路隧道勘察中,应用浅层地震勘探方法查明地下地质构造、风化带、分层等,并根据资料解释成果、钻探资料和工区地质资料,对隧道开挖过程中可能遇到的断层及塌陷等情况进行了讨论。 相似文献
4.
回顾了2003年以来中国IODP专家委员会的主要工作。10年来专家委员会开展了大量卓有成效的工作,提出了我国参加大洋钻探活动的战略和规划,组织了多种形式的学术活动,推动了我国深海科技事业蓬勃健康发展。 相似文献
5.
Rosi LIEM Research Engineers Institute of Hydraulic Engineering Water Resources Management Aachen Univer-s of Technology Germany Volker SPORK Research Engineers Institute of Hydraulic Engineering Water Resources Management Aachen Univer- 《国际泥沙研究》1997,(3)
I.INTRODUCTIONToconstructanidealmeasuringdeviceforin-situstUdiesincomparisontolaboratorydeVicesastrongeremphasishastobesetonthehandlingoftheSystemandtheresistanceunderwater,whichaughtbethereasonwhynotmanyapproachesonrealin-situinvestigationwerecaaccedoutlately.Sincetheedupandtheconstructionseemtodemandahigheramountofcostsandeffort,quasiin-siamstudieswerecAnedoutrefetringtoanundisturbedsedimentsampledrawnfromthesedimentbedoutofthewaterintothesamplingchamberofameasuringdevice.Evenifthisisa… 相似文献
6.
基于实践,分析了现有无纸化考试系统中试题难度的处理办法,结合专家经验和项目反应理论,给出了本课题所研发的考试系统中试题难度确定方法。该方法简明实用,能较好地控制试题难度,提高考试的公平合理性,通过对试题难度的分析,可提高教学和培训质量;具有自适应功能,为将来智能化出题打下基础。 相似文献
7.
勘察工作如同工业产品生产一样,也需遵循一定的程序步骤。本文论述了勘察工作应遵循的基本工作步骤,并对每个工作步骤的内容、作用及存在的问题进行了介绍,对部分工作之间的相互制约关系进行了阐述,同时,也对一些常见的问题提出了解决对策。作者想通过本文的论述,揭示了勘察工作各个环节之间存在着千丝万缕的联系,我们需要认真对待每一个环节,所有从事勘察工作的人员都要高度重视按程序步骤进行勘察工作的重要性,要从勘察作业程序上对勘察工作进行保障。 相似文献
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9.
E. M. Frempong 《Environmental Geology》1999,37(3):255-260
An engineering geological investigation has been undertaken of a proposed landfill site in coastal southwestern Ghana which
is characterized by torrential rains, high relative humidity, shallow groundwater conditions and almost surrounded by a ridge.
The study shows that the site has some desirable characteristics such as availability of suitable soils for the construction
of the capping and bottom liners of the landfill, a large tract of land for landfilling operation and its location close to
a major highway. However, the groundwater table was shallow and there was a high potential for leachate intrusion into and
consequent contamination of nearby groundwater abstraction wells and surface potable water sources thereby constituting serious
threat to life. Construction costs could be prohibitive as extensive dewatering and backfilling of vast portions of the project
site would be required to enable the provision of a separation between the shallow water table and the bottom of the landfill.
Received: 20 January 1998 · Accepted: 26 May 1998 相似文献
10.
