• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.2
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• pp.141-157
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• 2012

For the application TBM tunneling method, Both tunnel design standard and case study designed & constructed in domestic and foreign have been conducted. According to the study, the number of lane and inner shape (single or duplex) vary depending on the volume of traffic. Also extra space located in the top and bottom of tunnel is used for a multipurpose such as ventilation, disaster prevention, maintenance and administration. To find area ratio according to the components of road TBM tunnel, a standard section was considered as a two-lane road. Then, the analysis of area ratio of this section which consists of components for clearance, extra space in upper and lower tunnel was carried on two widths of shoulder. In addition, after a structural analysis, a thickness requirement of lower slab which is essential for road tunnel was derived on a few supporting types. Through correlation analysis, the ranges of available cross-sectional area between slab thickness and lower extra space of the tunnel was presented.

• Journal of the Korean Geosynthetics Society
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• v.17 no.1
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• pp.85-93
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• 2018

A existing standard design section of transitional zone between bridge and earthwork section in high speed railway should be designed to gradually change support stiffness from bridge abutment to backfill side that were placed on cemented stabilized gravel, general gravel, soil materials. The larger the backfill slope of the general gravel and soil was more structurally stable, but there is no clear reason about them. In this study, it was compared with settlement and bearing capacity of backfill area in currently design and alternating backfill slope section using large centrifuge tester. As the experimental results, it was showed that the 1:2 slope and 1:1.5 slope have almost similar bearing capacity behavior under the load stage as railway loading level.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.6
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• pp.383-390
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• 2019

A helideck is one of the essential structures in offshore platforms for the transportation of goods and operating personnel between land and offshore sites. As such, it should be carefully designed and installed for the safety of the offshore platform. In this study, a structural design optimization method for a lightweight offshore helideck is developed based on a genetic algorithm and an attainable design set concept. A helideck consists of several types of structural members such as plates, girders, stiffeners, trusses, and support elements, and the dimensions of these members are typically pre-defined by manufacturers. Therefore, design sets are defined by collecting the standard section data for these members from the American Institute of Steel Construction (AISC), and integer section labels are assigned as design variables in the genetic algorithm. The objective is to minimize the total weight of the offshore helideck while satisfying the maximum allowable stress criterion under various loading conditions including self-weight, wind direction, landing position, and landing condition. In addition, the unity check process is also utilized for additional verification of structural safety against buckling failure of the helideck.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.4 s.56
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• pp.107-115
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• 2009

The number of railway tunnel design is increasing recently compare to a great number of highway tunnel design which had increased with a lot of highway construction in the 70's and 80's. Therefore, there is more or less difference of time between highway tunnel and railway tunnel. In this paper, numerical analysis on two kinds of tunnels, such as two-forked road highway ventilation tunnel and double track railway tunnel with 4.3m of center line, in cases of with support materials condition and without support materials condition were conducted. Finally, stability of two kinds of tunnels were compared and analyzed through comparing of principal stresses and deviator stresses in the near base rock of tunnels using results of numerical analysis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5D
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• pp.677-684
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• 2008

The paper provides an approximate cost estimating model that can be used for tunnel. Based on the previous study analyzed critical factors that have impact on tunnel construction cost, this paper establishes a cost variance index table that reflects the cost impacts due to the change of the critical cost factors. An estimating procedure is described utilizing the index table. For the verification of the suggested model, the comparison of the estimated construction cost with real project cost is performed. The estimated results range from 95%~111% of the real project costs. As an approximate tunnel cost estimating model, the model can be utilized to quickly estimate tunnel construction costs based on the conceptual information at the planning stage and to efficiently make a decision on design alternatives.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.11a
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• pp.153-154
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• 2013

내화구조로 인정을 받은 국내의 철골조 기둥의 경우 대다수가 H형강에 내화제품을 피복한 구조이다. 본 연구에서는 한국산업표준에서 제시하고 있는 단면형상계수를 기준으로 H형강 인정구조와 다양한 단면의 내화구조의 비교실험을 통해 국내 인정제도를 개선하기 위한 자료로 활용하고자 하였다.

• Journal of Bio-Environment Control
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• v.20 no.1
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• pp.50-57
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• 2011

This study investigates the structural safety of typical greenhouse to be utilized for developing plant factory. New long-span greenhouse systems were presented according to the results of structural analyses performed by finite-element program, ABAQUS. Reasonable values of design loads such as wind and snow loads in the Greenhouse Design Specifications (1995) were applied to check the new greenhouse systems. It was concluded that the new greenhouse systems were consistently safe enough to resist to both wind load and snow load. The new greenhouse system can be used to make simple and economic plant factory.

• Fire Science and Engineering
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• v.26 no.6
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• pp.72-77
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• 2012

When the concrete and steel combined composite beam is exposed to high temperature, concrete could delay temperature rising of steel by covering or increase heat capacity of structural member. For becoming of structural reinforcing by unification between materials, fire resistance rate of composite beam would be higher than simple steel beam. The temperature rising of exposed steel of composite beam is directly related with section shape and exposure length of steel. In this study, fire resistant tests were carried out for composite beams and steel beam with same thickness of spray-type fire resistant materials in standard fire, and after that, temperature histories were analysed and compared with shape factor. The correlation between steel temperature and shape factor was showed very high. This result suggests that if it can be predict the comparative advantage of member by factor which cause the performance enhancement, it could be conclude that an Standard Accreditation method can be adjust to members without indivisual certifiicate of accreditation.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.6
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• pp.214-224
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• 2008

Member force, strain and stress distribution of a section are obtained for optimized standard 25m~45m PSSC composite bridge subjected to dead and live load in order to interpret the effect of prestressing and deformation of tendon. The stress and strain distribution and moment capacity are obtained for both noncomposite and composite section and for allowable stress limit state, yield limit state and strength limit state. Reliability analysis is conducted after assuming limit states for stress and flexural strength. The reliability index for standard PSSC composite bridge which is designed to satisfy the allowable stress for flexural strength are higher than 3.5 which is required reliability indexes on American code for LRFD. Reliability of PSSC girder which is designed based on allowable stress of bridge design code is high for flexural strength.

• Magazine of the Korea Concrete Institute
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• v.6 no.1
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• pp.101-110
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• 1994

본 연구에서는 임의형상의 속의 찬 또는 중공 단면에 대한 비틀림 상수 및 전단응력 계산용 범용 프로그램 TORSION을 소개한다. Membrane Analogy로부터 차분법을 유도한 뒤 Successive Over Relaxation 방법을 사용하여 정해를 효과적으로 얻을 수 있었다. 사각단면 이외 단면의 경우, 경계조건을 전체 Boundary Mesh에 대하겨 계산 입력해야하는 번거러움을 해격하기 위하여 자동경계 생성기법을 사용하였다. 개발된 프로그램 TORSION을 사용한 Parametric 해석을 통하여 비교적 정확한 일반 중공단면용 비틀림상수 계산을 위한 개략식을 제안한후, 콘크리트 표준시방서에 제시된 방법과 비교하였다.