• Title/Summary/Keyword: local soil conditions

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Study on Physical Characteristics of Historical and Artificial Ground Acceleration (역사지진 및 인공지진의 물리적 특성에 관한 연구)

  • 이대형;정영수;전환석
    • Journal of the Earthquake Engineering Society of Korea
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    • v.2 no.2
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    • pp.35-44
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    • 1998
  • Because of the continual occurrence of minor and moderate earthquakes in Korean peninsula, it is generally considered that Korean is not located in a safe region against probable earthquake any more, even though being recognized as a safe country in earthquake. It is in particular noted that nowadays there has been much concern about unexpected tragedy due to probable earthquake since the disaster of 1995 kobe earthquake. Thus, the objective of this research is to develop appropriate design spectrum which could be practicably used in seismic design of important structures taking into consideration of local physical characteristics. Particularly, we have to keep in mind the lessons from 1985 Mexico earthquake which had disregarded deep research on local ground conditions, being a possible magnification phenomena of ground motions in weak soil layer. Various spectra has been described based on the analysis of historical earthquakes, and generate the artificial ground acceleration. Also, rational numbers of artificial ground acceleration is investigated by the seismic analysis for skew slab bridges.

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A Study on the Long-term Settlements Characterlistics and Settlement Prediction of Soft Ground in West-South Region (서남권 연약지반의 장기침하 특성과 침하예측에 관한 연구)

  • Lee, Seungho;Jung, Jisu;Ji, Younghwan;Kim, Sungmun
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.4
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    • pp.77-91
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    • 2012
  • Recently, construction of housing sites, complexes, roads, ports and airports is increasing for high-intensity use of the country and balanced development between regions. Presently, constructions are being conducted at soft ground. Consequently, engineering problems as long-term settlement of the ground, differential settlement, local structural damage have been reported consistently at construction site. In particular, long-term subsidence of the ground as various constructions and loads by the load will necessarily occur in the soft ground of west-south coast and inland coast. Therefore, in this study, regional proper analysis methods of the Hyperbole method, Hosino method, $\sqrt{S}$ method, Asaoka method etc as existing long-term settlement prediction methods have been examined and a study on new prediction method was conducted through deduction of a generalized equation. Correlation coefficients of soil properties and construction conditions has been analyzed and a matching coefficient of long-term settlement characteristics has been deducted. Comparison and analysis of monitoring data and numerical analysis results of 16 local area have been conducted.

Estimation of Resident Support Fund Regarding Types of Environmental Foundational Facilities - Focus on Gangwon Provincial Government - (환경기초시설별 주민지원금 산정방안 - 강원도 중심으로 -)

  • Choi, Yong-Bum;Lee, Hae-Seung
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.9
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    • pp.905-910
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    • 2006
  • This research is conducted to calculate optimum residents grant regarding types of environmental foundational facilities. In the case of Gangwon province, it was particularly referred in this study, the residents grant of waste treatment facilities was excessively discharged as $1.6{\sim}75.0%$ of construction cost. This kind of excessive residents grant has overweighted the local governments' financial conditions. Accordingly, it is necessary to increase the amount of charge on the national treasury. In the calculation method of optimum residents grant reasonable resident support fund of waste treatment facilities was computed the range of 20%, food waste treatment facilities was 10% ranges and sewage and night soil combination treatment facilities was $3{\sim}5%$ ranges.

An empirical bracketed duration relation for stable continental regions of North America

  • Lee, Jongwon;Green, Russell A.
    • Earthquakes and Structures
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    • v.3 no.1
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    • pp.1-15
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    • 2012
  • An empirical predictive relationship correlating bracketed duration to earthquake magnitude, site-to-source distance, and local site conditions (i.e. rock vs. stiff soil) for stable continental regions of North America is presented herein. The correlation was developed from data from 620 horizontal motions for central and eastern North America (CENA), consisting of 28 recorded motions and 592 scaled motions. The bracketed duration data was comprised of nonzero and zero durations. The non-linear mixed-effects regression technique was used to fit a predictive model to the nonzero duration data. To account for the zero duration data, logistic regression was conducted to model the probability of zero duration occurrences. Then, the probability models were applied as weighting functions to the NLME regression results. Comparing the bracketed durations for CENA motions with those from active shallow crustal regions (e.g. western North America: WNA), the motions in CENA have longer bracketed durations than those in the WNA. Especially for larger magnitudes at far distances, the bracketed durations in CENA tend to be significantly longer than those in WNA.

Evaluation of Site Specific Ground Response (부지 고유의 지반 거동평가)

  • 김동수;이진선;윤종구
    • Journal of the Earthquake Engineering Society of Korea
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    • v.3 no.4
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    • pp.1-10
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    • 1999
  • Free-field ground motion during earthquake is significantly affected by the local site conditions and it is essential for the seismic design to perform the site specific ground response analysis. In this paper, the procedures of site specific ground response analysis were suggested based on the Korean seismic guideline and the review of state of the art technologies. The concept of ground response analysis was introduced, and the techniques of obtaining soil data for one dimensional equivalent linear analysis which include site investigation planning, field and laboratory testing techniques, deformational characteristics of soils at small to large strains, and site characterization techniques combining field and laboratory test results, were suggested. Finally, the case study was performed at Inchon area following the suggested procedure.

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Production of Gluconic Acid by Some Local Fungi

  • Shindia, A.A.;El-Sherbeny, G.A.;El-Esawy, A.E.;Sheriff, Y.M.M.M.
    • Mycobiology
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    • v.34 no.1
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    • pp.22-29
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    • 2006
  • Forty-one fungal species belonging to 15 fungal genera isolated from Egyptian soil and sugar cane waste samples were tested for their capacity of producing acidity and gluconic acid. For the tests, the fungi were grown on glucose substrate and culture filtrates were examined using paper chromatography analysis. Most of the tested fungi have a relative wide potentiality for total acid production in their filtrates. Nearly 51% of them showed their ability of producing gluconic acid. Aspergillus niger was distinguishable from other species by its capacity to produce substantial amounts of gluconic acid when it was cultivated on a selective medium. The optimized cultural conditions for gluconic acid yields were using submerged culture at $30^{\circ}C$ at initial pH 6.0 for 7 days of incubation. Among the various concentrations of substrate used, glucose (14%, w/v) was found to be the most suitable carbon source for maximal gluconic acid during fermentation. Maximum values of fungal biomass (10.02 g/l) and gluconic acid (58.46 g/l) were obtained when the fungus was grown with 1% peptone as sole nitrogen source. Influence of the concentration of some inorganic salts as well as the rate of aeration on the gluconic acid and biomass production is also described.

A Study on Design and Fabrication of SRD Impulse Generator and Antenna for Ground Penetrating Radar System (지반투과 레이더 시스템을 위한 SRD 임펄스 발생기 및 안테나의 설계 및 제작에 관한 연구)

  • Kim, Hyoung-Jong;Shin, Suk-Woo;Choi, Gil-Wong;Choi, Jin-Joo;Shin, Shang-Youal
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.3
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    • pp.509-516
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    • 2011
  • In this paper, a ground penetrating radar(GPR) system is implemented for landmine detection. The performance of the GPR system is associated with the characteristics of local soil and buried target. The choice of the center frequency and the bandwidth of the GPR system are the key factors in the GPR system design. To detect a small and shallow target, the higher frequencies are needed for high depth resolution. We have been designed, fabricated and tested a new impulse generator using step recovery diodes. The measured impulse response has an amplitude of 6.2V and a pulse width of 250ps. The implemented GPR system has been tested real environmental conditions and has proved its ability to detect a small buried target.

Public Perceptions and Support of Environmental Management in the Source Area of Drinking Water for Beijing, China

  • Wang, Xiaoyan;Feng, Qing;Zhang, Yafan;Duan, Shuhuai;Novotny, Vladimir
    • Environmental Engineering Research
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    • v.15 no.1
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    • pp.49-56
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    • 2010
  • Based on a survey of citizens and data analysis on the environmental status of the Miyun Reservoir watershed, China, the environmental awareness of citizens residing in the watershed and the impacting factors are discussed. The contingent valuation method was used to evaluate the willingness of villagers to pay (WTP) for abatement of the rural domestic pollution and to assess the intensity level of the villagers' desire for improving environmental conditions in the Miyun Reservoir watershed. It was found that rural watershed residents had a fundamental cognitive understanding of the pollution status and protection measures of the Miyun Reservoir. However, based on the survey, local residents had only a small interest in their participation to improve the environmental status of the reservoir, despite their general attitude to protect the reservoir being very positive. Gender and family income were closely associated with the overall attitudes of the population. Public media are the most preferable means for conveying knowledge of environmental protection to people living in the watershed. Increasing the educational level, along with income, are the best ways to enhance the desire of the villagers to improve the environmental quality and management.

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.

Spore Inoculum Effectiveness of Korean and American Strains of Ectomycorrhizal Fungus Pisolithus tinctorius under Nursery Conditions (한국산(韓國産)과 미국산(美國産) 모래밭버섯 균근균(菌根菌)의 리기테다 소나무 파종균(播種苗)에 대한 포자접종효과(胞子接種効果) 비교(比較))

  • Lee, Kyung Joon;Koo, Chang Duck
    • Journal of Korean Society of Forest Science
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    • v.65 no.1
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    • pp.43-47
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    • 1984
  • Pinus rigida ${\times}$ P. taeda seedlings in a nursery was inoculated with basidiospores of Pisolithus tinctorius (Pt) either collected from Suweon, Korea or introduced from U.S.A. to compare the effectiveness of the spores from two different origins as mycorrhizal inocula. Nursery beds were fumigated with methyl bromide and 1g of spores was used to inoculate $1m^2$ of soil surface just before seed sowing. Seedlings inoculated with American Pt (#250 strain from Georgia, U.S.A.) were 15% taller than Korean Pt at the end of the first growing season. The seedlings from fumigation treatment only (no inoculation involved) was slightly taller (statistically unsignificant) than those with Korean Pt, but slightly smaller than those with American Pt. In a subsequent year experiment, the seedlings inoculated with American and Korean Pt after soil fumigation were 66% and 60% taller, respectively, than seedlings infected by natural fungi without soil fumigation, suggesting the dual effects of Pt and fumigation on the seedling growth. Therefore potential of Pt spores for an effective inoculum exists and selection of Pt strains which have adapted to specific local environments is needed to develop better sources of mycorrhizal inocula.

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