• Title/Summary/Keyword: Carrying capacity model

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Experimental Performance Verification of Load Carrying Capacity Algorithm of Bridges using Ambient Vibration (상시진동을 이용한 교량 내하력 추정 알고리즘의 실험적 성능 검증)

  • Lee, Woo-Sang;Park, Ki-Tae;Han, Sung-Ho
    • Journal of the Korean Society of Safety
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    • v.25 no.3
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    • pp.83-90
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    • 2010
  • In this study, it is conducted that the performance verification of the ambient load carrying capacity algorithm using long-term measurement systems of bridges. For this purpose, a steel-box type model bridge is fabricated and the public load carrying capacity of a steel-box model bridge is estimated by conducting the numerical analysis and load test. In addition, we compare the public load carrying capacity with the estimated result of a steel-box model bridge using the ambient load carrying capacity algorithm. By the assessment result, it is shown that the estimated ambient load carrying capacity is the difference of approximately 6.0 percentages as compared with the public load carrying capacity.

Sustainable Land Use within a Limit of Environmental Carrying Capacity in Metropolitan Area, Korea (지속가능한 발전을 위한 환경용량의 산정과 토지이용형태 연구 - 수도권지역을 중심으로 -)

  • Moon, Tae-Hoon
    • Korean System Dynamics Review
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    • v.8 no.2
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    • pp.51-82
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    • 2007
  • The purpose of this paper is exploring changes in land use pattern when considering environmental carrying capacity. A sustainable development requires a society to define sustainability constraints, environmental carrying capacity. Environmental carrying capacity can be defined as a level of human activity a region can sustain at a desired level of quality of environment. This concept of environmental carrying capacity can be applied to land use to explore sustainable land use pattern. Since land use pattern can affect environment in an important way, exploring sustainable land use pattern within the limit of environmental carrying capacity can suggest useful implications for a sustainable regional management and planning. For this purpose, this paper built the environmental carrying capacity land use model and applied it to the Metropolitan Area, Korea. System dynamics modeling methods was used to build the model. The model developed in this paper consisted of 6sectors; population, housing, industry, land, environment, and traffic sector. The model limits its main focus on the NO2 level as an indicator of quality of environment in Metropolitan Area. Box model was translated into system dynamics model and combined to urban dynamics model to estimate NO2 level, the maximum number of population, industry structure, housing and maximum amount of land use for industrial, housing, and green space that can sustain desirable NO2 level. Metropolitan area was divided into 16 areas and the model was applied to each area. Since NO2 is flowing in and out from each area, model was built to allow this transboundering nature of air pollutants. Based on the model estimation, several policy implications for a sustainable land use pattern was discussed.

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A Study on Social Carrying Capacity in Outdoor Recreation Setting: An Exploratory Analysis on the Perceived Crowding Path Model in National Park (옥외휴양공간에서의 사회적 수용능력연구: 국립공원에서의 혼잡지각의 경로모형 분석)

  • Park, Chung In
    • KIEAE Journal
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    • v.5 no.1
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    • pp.35-42
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    • 2005
  • The primary concerns of recreation plan are to provide visitors with quality of recreational experience and to protect of recreation resources. The quality of recreational experience is often defined in terms of social carrying capacity. The carrying capacity is revealed as perceived crowding. In this respects, measuring perceived crowding is useful tool of social carrying capacity determination. This study is to test the structural equation model that includes variables affecting perceived crowding. Through an on-site questionnaire survey, 467 visitors on Naejangsan national park were collected. The results of the study are follows. The encounter level on facility area is higher evaluated as crowding factor than other area in the park. It can be concluded that visitor perceived crowding when facility area situates high density use level rather than other areas expose high density use level. In the path analysis, the input variables(attitude, experience, encounter level) on the structural equation model affect significantly on perceived crowding. Especially, the attitude on the park management polocy is the most affecting factor on perceived crowding.

Strength Prediction of Corbels Using Strut-and-Tie Model Analysis

  • Kassem, Wael
    • International Journal of Concrete Structures and Materials
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    • v.9 no.2
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    • pp.255-266
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    • 2015
  • A strut-and-tie based method intended for determining the load-carrying capacity of reinforced concrete (RC) corbels is presented in this paper. In addition to the normal strut-and-tie force equilibrium requirements, the proposed model is based on secant stiffness formulation, incorporating strain compatibility and constitutive laws of cracked RC. The proposed method evaluates the load-carrying capacity as limited by the failure modes associated with nodal crushing, yielding of the longitudinal principal reinforcement, as well as crushing or splitting of the diagonal strut. Load-carrying capacity predictions obtained from the proposed analysis method are in a better agreement with corbel test results of a comprehensive database, comprising 455 test results, compiled from the available literature, than other existing models for corbels. This method is illustrated to provide more accurate estimates of behaviour and capacity than the shear-friction based approach implemented by the ACI 318-11, the strut-and-tie provisions in different codes (American, Australian, Canadian, Eurocode and New Zealand).

Load carrying capacity of deteriorated reinforced concrete columns

  • Tapan, Mucip;Aboutaha, Riyad S.
    • Computers and Concrete
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    • v.6 no.6
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    • pp.473-490
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    • 2009
  • This paper presents a new methodology to evaluate the load carrying capacity of deteriorated non-slender concrete bridge pier columns by construction of the full P-M interaction diagrams. The proposed method incorporates the actual material properties of deteriorated columns, and accounts for amount of corrosion and exposed corroded bar length, concrete loss, loss of concrete confinement and strength due to stirrup deterioration, bond failure, and type of stresses in the corroded reinforcement. The developed structural model and the damaged material models are integrated in a spreadsheet for evaluating the load carrying capacity for different deterioration stages and/or corrosion amounts. Available experimental and analytical data for the effects of corrosion on short columns subject to axial loads combined with moments (eccentricity induced) are used to verify the accuracy of proposed model. It was observed that, for the limited available experimental data, the proposed model is conservative and is capable of predicting the load carrying capacity of deteriorated reinforced concrete columns with reasonable accuracy. The proposed analytical method will improve the understanding of effects of deterioration on structural members, and allow engineers to qualitatively assess load carrying capacity of deteriorated reinforced concrete bridge pier columns.

Evaluation of Carrying Capacity and Sustainability of Jeju Island using Onishi Model (Onishi Model을 이용한 제주도 기반시설 환경용량 산정 및 지속가능성 평가)

  • Park, Jinseon;Kim, Solhee;Kim, Yooan;Hong, Sewoon;Suh, Kyo
    • Journal of Korean Society of Rural Planning
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    • v.26 no.2
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    • pp.95-106
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    • 2020
  • The Onishi model is an objective indicator which can be used to evaluate the relevance of city environmental management in regard to the capacities and processing status of existing urban infrastructure. This study is to analyze the facility carrying capacity and processing status of Jeju Island, a famous tourist site in South Korea. General variables covered by the Onishi model are considered, including water supply, wastewater treatment, waste disposal, and air pollution. Furthermore, the facility carrying capacities for transportation, such as airports and ports, as well as accommodations are assessed as variables pertinent to the characteristics of Jeju island. With the annual number of tourists exceeding that of residents on the island, more facilities for sewage treatment and waste disposal are required. Furthermore, transportation and accommodations used by tourists have already exceeded their capacity. For the future sustainability of Jeju Island, a plan will be needed for adjusting the volume of tourists based on the capacity of each relevant facility.

Analysis of Discriminant Accuracy of Estimated Load Carrying Capacity in Bridges (교량 추정 내하율 판별 정확도 분석)

  • Kyu San Jung;Dong Woo Seo;Byeong Cheol Kim;Gun Soo Kim;Ki Tae Park;Woo Jong Kim
    • Journal of Korean Society of Disaster and Security
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    • v.16 no.4
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    • pp.123-128
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    • 2023
  • This paper presents the results of an analysis of the discrimination accuracy of a bridge load carrying capacity estimation model based on data from inspection reports. The load carrying rate estimation model was derived using statistical methods through the collection of 2,161 inspection reports. By entering the bridge specifications and maintenance information, you can check the estimated load carrying capacity of the bridge. In order to verify the discrimination accuracy of the estimated load carrying rate model, the estimated load carrying rate was compared with the load carrying rate in the inspection and diagnosis report for 164 public bridges for which data was available. Although there are differences depending on the bridge type, the results were obtained with an accuracy of over 80% in determining the estimated load carrying capacity.

Evaluation of Bridge Load Carrying Capacity of PSC Girder Bridge using Pseudo-Static Load Test (의사정적재하시험을 이용한 PSC 거더교의 공용 내하력평가)

  • Yoon, Sang-Gwi;Shin, Soobong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.4
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    • pp.53-60
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    • 2019
  • In this study, a method for updating the finite element model of bridges with genetic algorithm using static displacement were presented, and verified this method using field test data for PSC girder bridge. As a field test, static load test and pseudo-static load test were conducted, and updated the finite element model of test bridge using each test data. Finally, evaluated the bridge load carrying capacity with updated model using pseudo-static load test's displacement data. To evaluate the bridge load carrying capacity, KHBDC-LSD, KHBDC and AASHTO LRFD's live load model were used, and compared the each results.

Reliability-Based Assessment of Safety and Residual Load Carrying-Capacity of Curved Steel-Box Ramp Bridges (신뢰성에 기초한 강상형 곡선램프교의 안전도 및 잔존내하력 평가)

  • Cho, Hyo-Nam;Choi, Young-Min;Min, Dae-Hong
    • Journal of Korean Society of Steel Construction
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    • v.9 no.1 s.30
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    • pp.51-63
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    • 1997
  • Highly curved steel-box bridges are usually constructed as ramp structures for the highway interchange and metropolitan elevated highway junction, but a number of these bridges are deteriorated and damaged to a significant degree due to heavy traffic. The main objective of the study is to develop a practical reliability-based assessment of safety and residual load carrying-capacity of existing curved steel-box ramp bridges. In the paper, for the realistic assessment of safety and residual load carrying-capacity of deteriorated and/or damaged curved steel-box bridges, an interactive non-linear limit state model is formulated based on the von Mises's combined stress yield criterion. It is demonstrated that the proposed model is effective for the assessment of reliability-based safety and the evaluation of residual load carrying-capacity of curved steel-box bridges. In addition, this study comparatively shows the applicability of various reliability analysis methods, and suggests a practical and effective one to be used in practice.

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Carrying Capacity and Fishery Resources Release in the Bangjukpo Surfzone Ecosystem (방죽포 쇄파대생태계의 수용력과 수산자원방류)

  • KANG Yun Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.36 no.6
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    • pp.669-675
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    • 2003
  • To increase fishery resources in coastal waters, juvenile fish and bivalves are artificially released every year in Korea. This study provides a methodology to estimate an optimal release quantity based on the carrying capacity of the receiving basins. Carrying capacity was defined by E.p. Odum's theory of ecosystem development as the upper limit of biomass, where total system respiration equals total primary production. The Ecopath trophic ecological model was used to determine carrying capacity in the surfzone ecosystem of Bangjukpo on the southern coast of Korea. Using a top-down control method, various biomasses of fish groups were given to the simulation, with primary production constant and no catch. The results showed that biomass of selected fish groups increased by two orders of magnitude, yielding a five-fold increase in overall consumer biomass. The resultant values are 10 times higher than those estimated in open seas. This can be explained by higher primary production in the Bangjukpo surfzone ecosystem. This method can be used for strategic releases and ecosystem management, particularly when based on an ecological background.