• Title/Summary/Keyword: Alluvial

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Site effect microzonation of Babol, Iran

  • Tavakoli, H.R.;Amiri, M. Talebzade;Abdollahzade, G.;Janalizade, A.
    • Geomechanics and Engineering
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    • v.11 no.6
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    • pp.821-845
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    • 2016
  • Extensive researches on distribution of earthquake induced damages in different regions have shown that geological and geotechnical conditions of the local soils significantly influence behavior of alluvial areas under seismic loading. In this article, the site of Babol city which is formed up of saturated fine alluvial soils is considered as a case study. In order to reduce the uncertainties associated with earthquake resistant design of structures in this area (Babol city), the required design parameters have been evaluated with consideration of site's dynamic effects. The utilized methodology combines experimental ground ambient noise analysis, expressed in terms of horizontal to vertical (H/V) spectral ratio, with numerical one-dimensional response analysis of soil columns using DEEPSOIL software. The H/V spectral analysis was performed at 60 points, experimentally, for the region in order to estimate both the fundamental period and its corresponding amplification for the ground vibration. The investigation resulted in amplification ratios that were greater than one in all areas. A good agreement between the proposed ranges of natural periods and alluvial amplification ratios obtained through the analytical model and the experimental microtremor studies verifies the analytical model to provide a good engineering reflection of the subterraneous alluviums.

Text mining-based Data Preprocessing and Accident Type Analysis for Construction Accident Analysis (건설사고 분석을 위한 텍스트 마이닝 기반 데이터 전처리 및 사고유형 분석)

  • Yoon, Young Geun;Lee, Jae Yun;Oh, Tae Keun
    • Journal of the Korean Society of Safety
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    • v.37 no.2
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    • pp.18-27
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    • 2022
  • Construction accidents are difficult to prevent because several different types of activities occur simultaneously. The current method of accident analysis only indicates the number of occurrences for one or two variables and accidents have not reduced as a result of safety measures that focus solely on individual variables. Even if accident data is analyzed to establish appropriate safety measures, it is difficult to derive significant results due to a large number of data variables, elements, and qualitative records. In this study, in order to simplify the analysis and approach this complex problem logically, data preprocessing techniques, such as latent class cluster analysis (LCCA) and predictor importance were used to discover the most influential variables. Finally, the correlation was analyzed using an alluvial flow diagram consisting of seven variables and fourteen elements based on accident data. The alluvial diagram analysis using reduced variables and elements enabled the identification of accident trends into four categories. The findings of this study demonstrate that complex and diverse construction accident data can yield relevant analysis results, assisting in the prevention of accidents.

Delineation of internal heterogeneities of Geum River point bar deposits in Buyeo area using GPR Data (지하 투과 레이다 조사를 통한 부여 지역 금강변의 충적 대수층 내부 불균질성 파악)

  • Rhee, Chul-Woo;Kim, Hyoung-Soo;Lee, Kyung-Joo
    • Journal of the Korean Geophysical Society
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    • v.5 no.4
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    • pp.337-344
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    • 2002
  • The alluvial deposits along meandering rivers can be used as an artificial aquifer for infiltration of river waters. Internal heterogeneity of the alluvial deposits is a prerequisite information for the development of alluvial groundwater because vortical and lateral movement of alluvial ground water depends on the internal heterogeneity The internal heterogeneity due to variations in channel behavior can be delineated using GPR survey, GPR profiles for the point bar deposits near Buyeo county reveals two different stratigraphic units: the lower inclined heterogeneous strata and the upper horizontally stratified strata. The upper unit is largely indicative of vertical accumulation by overbank floods within a floodplain, whereas the lower one represents typical point bar deposits formed by lateral accretion. The stratigraphic variation in the heterogeneity shows that GPR survey is a useful and necessary investigation method for the development of alluvial ground water.

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The Influence of the Characteristics of Drainage Basin on Depositional Processes of the Alluvial Fan: An Example from the Cretaceous Duwon Formation in Goheung Area (유역분지 특성에 따른 충적선상지의 퇴적작용: 고흥군 백악기 두원층의 예)

  • Lee, Kyung Jin;Park, Seung-Ik;Lee, Hyojong;Gihm, Yong Sik
    • Economic and Environmental Geology
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    • v.54 no.4
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    • pp.441-456
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    • 2021
  • The Cretaceous Duwon Formation was studied on the basis of sedimentologic analysis in order to unravel geologic conditions for the development of the streamflow-dominated alluvial fan under arid to semi-arid climatic conditions. The Duwon Formation unconformably overlies the Paleoproterozoic gneiss (basement). Based on the sedimentologic analysis, the Duwon Formation is interpreted to have been deposited in gravelly braided stream (FA-1) near the basement, laterally transitional to sandy braided stream (FA-2) and floodplain environments (FA-3) with distance (< 7 km) from the basement. Lateral changes in sedimentary facies and the well development of calcrete nodules in FA-3, together with radial paleocurrent directions measured in FA-1, are suggestive of the deposition of the Duwon Formation in streamflow-dominated alluvial fan under arid to semi-arid climatic conditions. Recent analysis of detrital zircon chronology suggests that sediments of the Duwon Formation were derived from the southwestern part of the Korean peninsula, including the western part of Yeongnam Massif and the southwestern part of Okcheon Belt. This implies the alluvial fan where the Duwon Formation accumulated had the large drainage basin. Because the large drainage basin can supply the significant amounts of water and temporarily store the sediments within the basin, watery floodwater carried sediments to the alluvial fan rather than the debris flows. Furthermore, the drainage basin largely composed of coarse-grained metamorphic and igneous rocks produced sand-grade sediments, preventing evolution of floodwater into debris flows. We suggest that combined effects of the large drainage basin and its coarse-grained metamorphic and igneous rocks provided favorable conditions for the development of streamflow-dominated alluvial fan, despite arid to semi-arid climatic conditions during sedimentation.

지하수 수위 변동을 이용한 지하수 함양률 산정(전주-완주, 곡성 지역)

  • 조민조;하규철;이명재;이진용;이강근
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2002.04a
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    • pp.217-220
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    • 2002
  • To investigate the conditions of groundwater resources In Jeonju, Wanju, and Goksung, a basic groundwater survey was performed. From the survey, various useful informations such as groundwater use, waterlevel distribution, water chemistry were obtained. This study focused on the analysis of the water levels, which were automatically monitored with pressure transducers or manually measured. The monitorings were conducted for both shallow wells completed in alluvial aquifers and deep wells in bedrock aquifers. The automatically monitored waterlevels for alluvial aquifer were also used for estimation of recharge in the study area. This study presents results of the investigation.

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