• Advances in concrete construction
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• v.1 no.1
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• pp.103-119
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• 2013

The applicability of limit analysis methods in design and assessment of concrete structures generally requires a certain plastic deformation capacity. The latter is primarily provided by the ductility of the reinforcement, being additionally affected by the bond properties between reinforcing steel and concrete since they provoke strain localization in the reinforcement at cracks. The bond strength of reinforcing bars is not only governed by concrete quality, but also by construction details such as bar ribbing, bar spacing or concrete cover thickness. For new concrete structures, a potentially unfavorable impact on bond strength can easily be anticipated through appropriate code rules on construction details. In existing structures, these requirements may not be necessarily satisfied, consequently requiring additional considerations. This two-part paper investigates in a theoretical study the impacts of the most frequently encountered construction details which may not satisfy design code requirements on bond strength, steel strain localization and plastic deformation capacity of cracked structural concrete. The first part introduces basic considerations on bond, strain localization and plastic deformation capacity as well as the fundamentals of the Tension Chord Model underlying the further investigations. It also analyzes the impacts of the hardening behavior of reinforcing steel and concrete quality. The second part discusses the impacts of construction details (bar ribbing, bar spacing, and concrete cover thickness) and of additional structure-specific features such as bar diameter and crack spacing.

• Journal of the Korea Institute of Building Construction
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• v.8 no.6
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• pp.139-145
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• 2008

The objective of this paper is to analyze the construction management capacity of Choseon Dynasty and suggest a new interpretation on the construction capacity of the time management by reviewing the time management case during a representative construction project, HwaSungk construction project implemented in the latter period of Choseon Dynasty around 200 years ago. which was described in HwaSungSungYoukEuGye. The analysis results of the time management capacity during the latter period of Choseon Dynasty depicted in the HwaSungSungYoukEuGye is summarized as follows: (1) It took 2 years and 6 months to complete the Hwasung construction project. However, all of the single buildings were constructed within 6 months, a relatively short period of time. Judging from the fact, it can be assumed that the construction techniques using wood of the time were very sophisticated. (2) When the HwaSung was constructed, it took a relatively short period of time to complete works from placing the foundation to erecting columns and to placing a crossbeam on the columns. Based on the fact, it can be also inferred that assembly processing techniques of the time were also sophisticated and the level of member processing and assembling techniques of the time was considerably good as well. (3) The HwaSung construction was continued throughout the year without any influence by weather conditions, which tells us that division of labor by work was performed, and it was possible to mobilize labor force for the construction project even during the busy farming seasons.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.545-553
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• 2009

A lot of long-span marine bridge, which connects land to island or island to island, are being designed and constructed lately in south-west coast in South Korea. In the past, caisson foundations in marine were mainly adopted in construction and stability aspect, however, nowadays with development of pile construction technology, drilled shaft foundations are mainly adopted. As the long span cable stayed bridge and suspension bridge applied with lots of loads are being designed, the scale of pile foundations are getting larger. As the construction cost of substructure including foundation in marine bridges is too high, the appropriate evaluation of the axial bearing capacity of pile becomes a core factor to decide the construction cost of foundation if the drilled shaft is adopted as foundation type of bridge. The evaluation values of skin friction and end bearing capacity of drilled shaft in weathered rock suggested in south Korea are only to introduce the foreign specifications, and most of them are designed in a kind of hard soil layer. Also the allowable load of pile section is less than the expected bearing capacity of pile in the soil condition since the allowable capacity of pile is undervalued. Recently in order to improve this factor the bi-axial hydraulic load test of pile was taken, the data of load transfer analysis of pile, unit of skin friction and end bearing capacity are accumulated. In our country, the design of piles are made with ASD, however, LRFD considering service, strength and extreme state was adopted in Incheon Grand Bridge implemented with BTL, and the research to systematize the resistance coefficient appropriate at home country are being progressed.

• Journal of the Korean Geotechnical Society
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• v.37 no.8
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• pp.15-24
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• 2021

Recently, cases for inevitable adjacent construction are increasing due to the limited spaces in urban area. When a new structure is constructed near an existing structure, interference effects induced by the pre-existing structure should be considered. Thus, numbers of studies have been conducted to investigate the effects of adjacent construction, while laboratory scales studies are not well reported. In this study, laboratory scale experiments have been conducted to investigate the bearing capacity and settlement variations with different adjacent construction cases. Results show an optimistic ground bearing capacity increase of the new foundation structure due to the existing foundation structure, while concerns on the increased settlement of the pre-existing structure. Thus, both bearing capacity of the new foundation structure and subsequent settlement of the existing foundation structure have to be considered when assessing the technical applicability of adjacent structure construction on site.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2004.05a
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• pp.101-104
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• 2004

If predicting of compressive strength of construction in construction field at early age is possibile, rational strength management & schedule plan is possible. With method for predicting strength of concrete, many researchers have been making study of maturity method. On the other hand, nowadays rationalization of construction capacity and reduction of a term of works due to improvement of construction capacity and application of a new method of construction is gathering strength with important issue. In accordance with this present condition, construction is being progressed in winter, but proper construction mothed and countermeasure for strength management is not established in case of winter construction. Therefore to investigate application in construction field at winter of strength prediction model that developed at former study, this study aim to measure application of developed strength prediction model through manufacture of mock-up concrete according to kind of strength level at 5$^{\circ}C$.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.517-520
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• 2005

The embedded suction anchor(ESA) is and anchor that is driven by a suction pile. The cross-sectional shape of the ESA anchor is circle. Its diameter is the same as that of the suction pile that is used to drive it into the seafloor. For the installation, the anchor is attached to the tip of the suction pile and then driven as a unit with the pile by and applied suction pressure. Once the ESA anchor reaches the desired depth, the pile is retrieved by applying a positive pressure. Finally, only the ESA anchor remains in the soil layer. This paper presents the results of centrifuge model tests to investigate ESA pullout capacity. The main parameters that have effects on the pullout capacity of ESA may include g-level, embedded depth, direction of loading, and loading point. The results of tests show that the pullout loading capacities increase as the loading point shift toward the tip of the anchors for a given loading direction. They also indicate that the loading point associated with the maximum pullout loading capacity is located at approximately 67 percent of the anchor length from the top for the horizontal load.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.666-672
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• 2010

Load bearing capacity of new lattice girder has been evaluated with optimized spider for lattice girder utilized in the construction of tunnels. This newly developed lattice girder is different from existing lattice girder as its design is associated with existing spider with newly developed 2 types of form. The spacing of lattice girder's spider is linked with the weight and it decides the unit cost and construction therefore, different spacing of the developed spider has been produced to evaluate the measurement of load bearing capacity. As the result of the tests by producing the spacing of spider as 0cm and 4cm for developed lattice girder-2, the load bearing capacity of 0cm with spacing of 21%, and 4cm with 25% of increase when they are compared with the existing lattice girder, and the weight of specimen was decreased. As the result of the tests by producing the spacing of 1cm and 6cm for developed lattice girder-3, the spacing of 1cm with 42%, and the spacing of 6cm with 11% of increase which presented higher load bearing capacity in all newly developed forms, and there was a certain degree of increase in weight in case of 1cm of spacing. The result of evaluation regarding on the displacement by applying the evaluation method suggested by the German Railroad administration, the entire specimens were found to satisfy all the evaluation standard suggested by the administration.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.794-799
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• 2008

At the point of changing from the capacity qualification of temporary equipments for building to safety certification system, the meaning of qualification and the present state of main products are evaluated for Capacity qualification system and compare with related system in developed country. These suggest classification of temporary equipments for building construction in safety certification. Now, present state of the capacity qualification system is estimated; according to the reforming system from restating law in 2003, there are a lot of changing of application in every 3 years because of that. The ability of Making business is improved by checking again but, there are limitation to constantly keep the safety as the system to approve form about sent imitation products. Changing from the capacity qualification system to safely certification system make to include the structure of the qualification system and make a plan standard. It make least panic in the building market and set up some standards for capacity by changing building circumstance. The classification of temporary equipment for building construction in safety certification from the module of quotation form classify each duty quotation item, self-regulation safely verification item and option quotation item, these will more improve the system form and quality of temporary equipment for building than before.

• Magazine of the Korean Society of Agricultural Engineers
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• v.10 no.1
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• pp.1413-1419
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• 1968

Yochon reservoir was consturcted with an original storage capacity of 202.7 chung-meters. This reservoir receives the water from watershed area of 933.0 chungbo and has irrigated area of 478.0 chungbo. In 1967 a detailed capacity survey of this reservoir was carried out by a new depth-recorder under the scheme of reservoir sedimentation of Agricultural Engineering Research Center. Significant findings are 1. The capacity of the reservoir for the water storage has been reduced by 8.9%(18.066 chung-meters out of the 202.7 chung-meters) since its construction, a period of just 39.0 years. 2. The sediment accumulation in the reservoir represents an average annual soil loss of 0.496mm depth(0.463 chung-meters) of soil from the watershed area of 933.0 chungbo. Eventually the capacity of the reservoir for the water storage will be reducing by about 25%(50.7 chung-meters out of the 202.7 chung-meters)in one hundred years since its construction. We have to set up controlling projects for those reservoir protections from the sediment, soil loss, and other failures. The depth recorder is very useful, convenient, and accurate machine for surveys of reservoir capacity and other river surveys.

• Journal of the Korea Institute of Building Construction
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• v.5 no.2 s.16
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• pp.139-146
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• 2005

As a result of compressive strength, specimens having mixture rate of cockle shells of $15\%\;and\;20\%$ showed more increases of compressive strength than non-mixture specimens as age increases. Ductility capacity of specimens was higher in specimens mixing cockle shells than in specimens using general fine aggregates and specimen of $10\%$ of cockle shells was highest in ductility capacity. To sum up all experimental results, ductility capacity of specimen without shear reinforcement using mixture of cockle shell was higher than non-mixture specimen and it is considered that mixture of cockle shells up to $20\%$ as fine aggregate for concrete will be available. Continuous researches on durability, workability and economy of crushed cockle shells used for substitute fine aggregate of concrete will be needed.