• Title/Summary/Keyword: Site Conditions

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Diurnal changes of Tissue Water Relations in Two Allopatric Tree Species (이소적 두 수종의 수분관계 일변화)

  • Park, Yong-Mok
    • The Korean Journal of Ecology
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    • v.19 no.5
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    • pp.453-463
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    • 1996
  • Diurnal changes of microclimatic conditions and tissue water relations were measured at two sites where Carpinus laxiflora and C. cordata were allopatrically distributed. The microclimatic conditions at a site where C. laxiflora was distributed produced severe water stress condition during summer months. Daily maximum temperature reached $30.4^\circC$ and the highest vapor pressure deficit was 1.31 KPa when 13 rainless days were continued. During this period soil water content decreased to below the field capacity even at a depth of 20 cm and xylem pressure potential also decreased to ­2.04 MPa. However, turgor potential was maintained more than 0.4 MPa. Patterns of stomatal conductance were changed with evaporative demand and soil water availability. On the other hand, microclimatic conditions at a site where C. cordata was distributed were moderate water strees condition compared with those at a site C. laxiflora was distributed. Though soil water content was maintained above field capacity C. cordata showed a remarkable decrease in turgor potential and stomatal conductance throughout the experiment. These results indicate that there is a difference in habitat characteristics between the two species and C. laxiflora is more resistant than C. cordata to water stress.

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Study on the selection of TBM in consideration of field conditions (시공여건을 반영한 TBM선정 방법에 대한 연구)

  • Oh, Joon-Geun;Sagong, Myung
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.16 no.2
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    • pp.125-133
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    • 2014
  • In this study, TBM selection methods to meet soil and site conditions were presented. Factors and excavation equipment affecting TBM selection by soil and environmental condition were selected and classified. Weights between equipment and influencing factors selected were calculated by applying the AHP (Analytic Hierarchy Process) method. The results of the analysis influence factors, Ground condition was a major factor in objective factors and strength was a major factor in the hard condition of criteria factors and water pressure was a major factor in the soft ground condition of criteria factors. In Environment condition, existence of adjacent structures was evaluated more important than existence of feasible site. Lastly, Adequacy was verified through the deduction of results that coincide with input equipment by applying derived weights to actual site conditions.

Investigation on site conditions for seismic stations in Romania using H/V spectral ratio

  • Pavel, Florin;Vacareanu, Radu
    • Earthquakes and Structures
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    • v.9 no.5
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    • pp.983-997
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    • 2015
  • This research evaluates the soil conditions for seismic stations situated in Romania using the horizontal-to-vertical spectral ratio (HVSR). The strong ground motion database assembled for this study consists of 179 analogue and digital strong ground motion recordings from four intermediate-depth Vrancea seismic events with $M_w{\geq}6.0$. In the first step of the analysis, the influence of the earthquake magnitude and source-to-site distance on the H/V curves is evaluated. Significant influences from both the earthquake magnitude and hypocentral distance are found especially for soil class A sites. Next, a site classification method proposed in the literature is applied for each seismic station and the soil classes are compared with those obtained from borehole data and from the topographic slope method. In addition, the success and error rates of this method are computed and compared with other studies from the literature. A more in-depth analysis of the H/V results is performed using data from seismic stations in Bucharest and a comparison of the free-field and borehole H/V curves is done for three seismic stations. The results show large differences between the free-field and the borehole curves. As a conclusion, the results from this study represent an intermediary step in the evaluation of the soil conditions for seismic stations in Romania and the need to perform more detailed soil classification analysis is highly emphasized.

A Study on the factors of Quality variation for High Flowing Concrete in Site (고유동 콘크리트의 품질변동 요인에 관한 연구)

  • Kwon Yeong-Ho;Lee Hyun-Ho;Lee Hwa-Jin;Ha Jae-Dam
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.743-746
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    • 2004
  • This research investigates experimentally an effect on the properties of the high flowing concrete according to variations of concrete materials and site conditions. Variations of sensitivity test are selected items as followings; (1)Concrete temperature, (2)Unit water(Surface moisture of fine aggregate), (3)Fineness modulus of fine aggregate, (4)Addition ratio of high-range water reducing agent. And fresh conditions of the high flowing concrete should be satisfied with required range including slump flow$(65{\pm}5cm)$, 50cm reaching time of slump flow$(4\~10sec)$, V-box flowing time$(10\~20sec)$, U-box height(min.300mm) and air content$(4{\pm}1\%)$. As results of sensitivity test, material variations and site conditions should be satisfied with the range as followings; (1)Concrete temperature is $10\~20^{\circ}C$ (below $30^{\circ}C$), (2)Surface moisture of fine aggregate is within ${\pm}0.6\%$, (3)Fineness modulus of fine aggregate is $2.6{\pm}0.2$ and (4)addition ratio of high range water reducing agent is within $1\%$ considered flow-ability, self-compaction and segregation resistance of the high flowing concrete.

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An Off-Site Consequence Modeling for Accident Using Monte Carlo Method (몬테칼로 방법을 사용할 사고후 영향 평가모델)

  • Chang Sun Kang;Sae Yul Lee
    • Nuclear Engineering and Technology
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    • v.16 no.3
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    • pp.136-140
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    • 1984
  • A new medal is presented in order to evaluate the risk from a nuclear facility following accidents directly combining the on-site meteorological data using the Monte Carlo Method. To estimate the radiological detriment to the surrounding population-at-large (collective dose equivalent), in this study the probability distribution of each meteorological element based upon on-site data is analyzed to generate atmospheric dispersion conditions. The random sampling is used to select the dispersion conditions at any given time of effluent releases. In this study it is considered that the meteorological conditions such as wind direction, speed and stability are mutually independent and each condition satisfies the Markov condition. As a sample study, the risk of KNU-1 following the large LOCA was calculated, The calculated collective dose equivalent in the 50 mile region population from the large LOCA with 50 percent confidence level is 2.0$\times$10$^2$ man-sievert.

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A Study on the Case of Application of a Process at the Construction Stage of the Color Planning at the Construction Site of Muju Taekwondo Park (무주 태권도원 현장 색채계획 시공단계 프로세스 적용사례연구)

  • Yun, Gye-Yeong
    • Korean Institute of Interior Design Journal
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    • v.22 no.5
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    • pp.320-327
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    • 2013
  • In order to maintain and protect professionalism in color planning, the present study examined the process at the time of realization of color through color inspection and supervision in the actual construction site and suggested plans for improvement. Reflecting the characteristics that the governing body of the construction site is not a private person but an organization, the present study aims to provide institutional measures so that the supervisor of color construction at the actual site of construction can propose concerns related to proper construction at the right time, and the matters cannot be decided from the perspective of a layman. The institutional measures are proposed through the case of application of a process at the construction stage of the color planning at the construction site of Muju Taekwondo Park. First, the process clarified where the responsibility lies by specifying special conditions concerning color inspection on the field guide and color contract. Second, the sample for building materials was selected after obtaining it from a company capable of supply and is appropriate for the planned unit cost so that it could play an important role in realizing colors at the stage of basic design. Third, the process of construction was ensured not by temporary selection of colors but by continuous approval of colors in consideration of the conditions of construction site through letter of approval of color at each stage and point of time. Fourth, coordination of various color elements of other fields including landscape, interior, and electricity ensured construction of the whole structure in one color concept. Fifth, color inspection through the mock up of the site will minimize erroneous construction and reconstruction and prevent decrease in productivity. Sixth, this study also suggested more comfortable and positive color environment through evaluation by experts and users. The researcher of this study expects that color experts actively participate in the stage of construction to contribute to improvement of the color environment.

AN EXPERIMENTAL STUDY ON THE PRODUCTION OF HIGH-STRENGTH CONCRETE PILE IN SITE (현장생산용 고강도 콘크리트 파일에 관한 실험적 연구)

  • 박칠림;권영호;백명종;이상수;정도순
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.04a
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    • pp.183-188
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    • 1995
  • Up to date, high-strength concrete pile which is producing in factory sells in the market. But according to the site and the construction conditions, the system to produce high-strength concrete pile directly in site is utilized in advanced country. Such the production system is the technique phenomenon very disirable in the side of quality control in site and the construction schedule, the time and the cost saving. This study is a fundamental experiment including concrete mixing design, non-autoclave curing method and the optimum condition to produce high-strengh concrete pile in site. As results of this study, High-strength concrete pile in site which target strength is 400kg/ $\textrm{cm}^2$ is able to produce it with optimum curing ciondition(75$^{\circ}C$, 9hr)and mixing design.

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Analysis of landing site for lander and rover on Moon and Mars

  • Seo, Haingja;Kim, Eojin;Kim, Joo Hyeon;Lee, Joo Hee;Choi, Gihyuk;Sim, Eun-Sup
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.105.1-105.1
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    • 2012
  • Moon and Mars have been explored by landers and rovers. Apollo missions landed five times on Lunar surface, and various rovers, including Curiosity landed and explored Mars. The selection of landing site have to be considered engineering and scientific side: the landing site to be available to land stably? the obstacle is not around the rover such as rocks and pothole? the landing site is valuable with scientific? And then landing site have to be the place which is satisfied two objects. We search the information about landing sites of Moon and Mars, and compile the conditions of landing sites. We expect that these data are useful when the landing site of Moon or Mars for Korean mission is selected.

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Automated 3D Model Reconstruction of Disaster Site Using Aerial Imagery Acquired By Drones

  • Kim, Changyoon;Moon, Hyounseok;Lee, Woosik
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.671-672
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    • 2015
  • Due to harsh conditions of disaster areas, understanding of current feature of collapsed buildings, terrain, and other infrastructures is critical issue for disaster managers. However, because of difficulties in acquiring the geographical information of the disaster site such as large disaster site and limited capability of rescue workers, comprehensive site investigation of current location of survivors buried under the remains of the building is not an easy task for disaster managers. To overcome these circumstances of disaster site, this study makes use of an unmanned aerial vehicle, commonly known as a drone to effectively acquire current image data from the large disaster areas. The framework of 3D model reconstruction of disaster site using aerial imagery acquired by drones was also presented. The proposed methodology is expected to assist rescue workers and disaster managers in achieving a rapid and accurate identification of survivors under the collapsed building.

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Verification of 2-Parameters Site Classification System and Site Coefficients (I) - Comparisons with Well-known Seismic Code and Site Response Characteristics (2-매개변수 지반분류 방법 및 지반 증폭계수의 검증 (I) - 국외 내진설계기준 및 부지응답특성과의 비교)

  • Lee, Sei-Hyun;Sun, Chang-Guk;Ha, Jeong-Gon;Kim, Dong-Soo
    • Journal of the Korean Geotechnical Society
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    • v.28 no.3
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    • pp.25-34
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    • 2012
  • In order to verify that the recently proposed two-parameters site classification system and the corresponding site coefficients are suitable for the local geological conditions in Korea, a comparison was conducted with current Korean seismic code, Eurocode-8, NYC DOT seismic code. The design spectrum of the current Korean seismic code is significantly amplified in the long-period range, whereas the other response spectra, including the proposed two-parameters approach, are significantly amplified in the short-period range, which is a typical geological condition in Korea. In addition, based on the results of site response analyses in the specific $10km{\times}10km$ area of Gyeongju, spatial distributions of site coefficients from site-specific seismic response analyses were compared with the proposed site coefficients, as well as those specified in the current Korean seismic code. The site coefficients ($F_a$ and $F_v$) from the current Korean seismic codes show significantly high spatial error distributions compared with those specified by the two-parameters site classification system. Therefore, the proposed system is suitable for regions of shallow bedrock including the Korean peninsula.