• Title/Summary/Keyword: engineering geology

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Engineering Geological Characteristics of the Cenozoic Strata (신생대 지층의 지질공학적 특성)

  • Yoon, Woon-Sang;Jeong, Ui-Jin;Park, Jeong-Hoon;Kim, Choon-Sik;Ann, Kyeong-Chol;Kim, Taek-Kon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.10a
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    • pp.231-238
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    • 2005
  • Incompetent sediments and competent volcanics are consisted of the Cenozoic geology in Korea. Although the Cenozoic area is small, it is necessary to special interesting for ground of these geological material. The Cenozoic geology shows heterogeneous characteristics. We can look at the weak Cenozoic sedimentary rocks under the hard Cenozoic basalt in the area. Some Cenozoic un(or half)-consolidated soft sediments have large, heavy and hard boulders. Some volcanics and tuffaceous sediments have swelling clays. These characteristics give very difficult problems to engineering geologists and civil engineers.

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The Datum Design Study of High Precision GPS Height Monitoring Network---- with the Example of Monitoring Land Subsidence & Ground Fissure in Xi'an City

  • Qin, Zhang;Li, Wang;Zhong, Liu;Guan-wen, Huang;Xiao-guang, Ding
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.1
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    • pp.229-234
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    • 2006
  • There are still some key problems having to be solved in theory and technique applications when GPS is used to monitor the vertical deformation of ground with high precision. Utilizing the GPS technology to monitor the deformation of the land subsidence and ground fissure in Xi'an, this paper puts forward advice that the datum frame of GPS network has significant influence on the precision and accuracy of the vertical deformation results by some research. The co-authors make some theoretical study of the datum error and practice by establishing the datum error models, especially the influence of scale and azimuth datum errors on GPS monitoring network. Then the datum frame design methods and arithmetic of GPS monitoring network are presented and have taken a good effect.

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Rock Permeability Estimation from Hydraulic Injection Tests in a Sealed Borehole Interval

  • Quach, Nghiep Q.;Jo, Yeonguk;Chang, Chandong
    • The Journal of Engineering Geology
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    • v.28 no.1
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    • pp.1-9
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    • 2018
  • We propose a borehole test technique to estimate permeability of rocks in borehole. The borehole tests are hydraulic injection tests such as leak-off test and hydraulic fracturing tests, which are originally conducted for stress or casing integrity assessment and not for permeability measurement. We use one-dimensional radial diffusion equation to interpret fluid injection test results in terms of permeability. We apply this technique to a leak-off test conducted at a depth of 700 m in a wellbore, where rock formation is mudstone. The estimated permeability is at an order of $10^{-16}m^2$, which is somewhat high but within the range reported for mudstones previously. Quantitative rick assessment suggests that an accurate measurement of open hole section length is important to improve reliability of results. More data may be needed to ensure the reliability of this technique. If validated, however, this technique can provide cost-effective estimation of in situ permeability without conducting independent permeability tests in borehole.