• Journal of Korean Association for Spatial Structures
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• v.7 no.2 s.24
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• pp.97-104
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• 2007

Recently, the demand of the large span structures has been increasing. The large span structures include such a large scaled structures such as: the shell structure, the space frame structure, the membrane structure and the cable structure, etc. The large span structures are supposed to be confirmed and issued carefully at the initial process of the design besides the construction engineering aspects because of the structural specific cause that should solve and accomodate those large and wide space without columns. In the field of the large span structure construction, the erection construction method has been regarded as a major affected aspects on the construction cost, construction term, and stability. In the field of the large span structure construction, there are various construction method and system could be applied depends on the condition of the construction site and other circumstances such a major construction method as: the element method, the block method, the sliding method, the lift-up method and complexed method, etc. In this study, as the case study of the erection construction method of the large span structures, after survey and study that those existing large span structures construction cases which had applied and adopted the election construction method and analysis and classify into the Uoups by the size, span, ceiling height, structural system in odor to supply and suggest the data for the enhancement and development in the field of the erection construction method as a efficient structural solution of the large span structure construction.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.77-78
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• 2023

As large logistics buildings have high floor heights and long spans, these buildings are designed as PC structures, and large cranes are used to lift PC members. PC erection planning can generally cause errors depending on the field engineer's experience. To solve this problem, a basic analysis method is needed to establish a systematic PC member erection plan. Crane work can be minimized if the trajectory is easily and quickly calculated according to the location of the crane and applied to the site. Therefore, the objective of this study is a basic study of crane trajectory distance calculation for sustainable PC members erection of large logistic building. In this study, a crawler crane commonly used for lifting PC members is limited. The trajectory distance for the PC erection plan was automatically calculated using the algorithm.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.229-233
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• 2011

Recently, the scale of buildings has been increasing because of the high-rise trend and complexity of underground spaces. A significant number of steel structures have therefore been adopted for building construction. Since workers need to work in high places to install steel beams, many industrial accidents easily occur during steel-frame work. Furthermore, considering the increasing trend of building steel structures, the safety of the workers during the steel beam erection work is of concern. To improve the safety, a new type of joint, located between the steel column and beam, which can eliminate the need for working at the elevated height during steel beam erection has been developed in Korea. Using the newly developed technology in the construction field, the safety performance needs to be evaluated. This study presented the safety evaluation approach for the newly developed technology from the literature review, and applied the method to a self-supported steel joint. The result showed that applying the self-supported steel joint improved the safety of the steel erection work in terms of working posture, working environment, and risk exposure time.

• Journal of the Korean Professional Engineers Association
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• v.19 no.2
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• pp.34-42
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• 1986

These brief studies and reports of the use of exposed aggrigate precast concrete in practice are combined with a description of some notable co-ordination such as shop drawing, manufacturing and erection in the field construction. Above mentioned exposed aggrigate P. C. means architectural P. C. which was used to the VOTRAKON site in Riyadh, Saudi Arabia. Fabricated P. C. on the site without autoclaving and steam curing plant had been successfully carried out on this project-core building, conference room and others. The project designed by HOPE/VTN international INC. which is located in San Diego, California U.S.A. stands for vocational training and related support facilities contract. We had to submit shop drawings showing complete information for fabrication and installation of P. C. unit reinforcement. Also we should be indicated member dimension and cross section, location size and type of necessary for erection. We can delineate the following characteristic results. One of the most important things how to handle exposed aggrigate P.C. unit as specified was quality assurance and co-ordination for shop drawing, manufacturing and erection.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.135-139
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• 2008

For deep basement construction of buildings downtown, the usage of Top-Down Method is increasing as much as ever from strong demand. One of the essential elements for the construction by Top Down Method is the pre-founded columns, which are installed in the ground and on which a building is installed. The fact that the pre-founded columns are placed in the ground makes them susceptible to its plumbness; this aspect distinguishes pre-founded columns from general columns. However, there are no criteria for erection tolerance. Therefore, field-measured-data concerning out-of-plumb of pre-founded columns in the construction field should be accumulated and investigated so that criteria and specifications for the erection tolerance of pre-founded columns may be established through the understanding of its aspects. In this paper, we investigate out-of-plumb of pre-founded columns for the construction case and analyze its aspects, and propose considerations for design and construction phase.

• Wind and Structures
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• v.6 no.1
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• pp.1-22
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• 2003

Nowadays balanced cantilever construction plays an essential role as a sophisticated erection technique of bridges due to its economical and ecological advantages. Experience teaches that wind has a great importance with regard to this construction technique, but methods proposed by codes to take wind effects into account are still rather crude and, in most cases, completely lacking. Also research in this field is quite limited and aimed at studying only the longitudinal shear and the torque at the pier base, caused by the mean wind velocity and by the longitudinal turbulence actions over the deck. This paper advances the present solutions by developing a new procedure that takes into account all wind effects both on the deck and on the pier. The proposed model assumes the mean wind velocity as orthogonal to the bridge plane and considers the effects produced by all the three turbulence components and by the vortex shedding. The applications point out the role of each loading component on different bridge configurations and show that disregarding the presence of some effects may imply oversimplified results and relevant underestimations.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.5A
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• pp.255-266
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• 2012

Main cable of a suspension bridge is the important member which shows the overall structure integrity at bridge completion. Configuration of main cable is a free hanging state at cable erection completion and is different from that at bridge completion supporting the dead loads such as hanger, girder, and so on. Accordingly, the configuration control under cable erection is considerably significant because the configuration at cable erection completion has direct influence on that at bridge completion. That is performed by sag adjustments at center, side span and tension adjustments at anchor span. The former needs the sag sensitivity which represents the control quantity of strand length corresponding to that of sag. The latter requires the tension sensitivity which shows the change of strand tension according to that of strand temperature. In this study, the fundamental equations of cable were derived with the assumption of either catenary or parabola shape, the differential-related equations using chain rule on horizontal tension were drawn from those and finally the estimation methods of the sag / tension sensitivity were proposed from both those. The nonlinear numerical analysis flow charts of sag sensitivity based on the catenary equations were proposed and the sag sensitivities grounded on the differential-related equations were compared with the results using them for various parameters of sag change. Also, considering the combinations of sag change parameters, the calculation method of the final variation for the cable sag was suggested. For the real suspension bridge under construction with PPWS method, the sag/tension sensitivity were estimated considering the construction conditions like the change of PPWS length, PPWS temperature, bridge span, etc.. We hope that this study will be a systematic guideline for the configuration control under main cable erection and improved highly by field verification in the real bridge site.

• Biomolecules & Therapeutics
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• v.11 no.4
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• pp.232-237
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• 2003

The present study examined functional effects of a new selective phosphodiesterase type 5 inhibitor, 1-[4-ethoxy-3-(6,7-dihydro-1-methyl-7-thioxo-3-propyl-1H-pyrazolo[ 4,3]pyrimidin-5-yl)phenylsulphonyl]-4-methyl piperazine (KJH-1002), in the isolated rabbit corpus cavernosum (RCC). Relaxing effects of KJH-1002 were also compared with those of sildenafil, which is currently used as an oral therapy for penile erectile dysfunction. In the isolated RCC precontracted with phenylephrine, both KJH-1002 and sildenafil in the concentration range of 1 to 1000 nM, produced a comparable potentiation of the electical field stimulation-induced relaxation in a concentration-dependent manner. In the sodium nitroprusside (SNP)-induced relaxation, the $IC_{50}$/ values, concentrations of SNP required to produce a 50％ relaxation of the phenylephrine-induced contraction, were significantly decreased to the similar extent by treatments with KJH-1002 and sildenafil. The results suggest that a new selective phosphodiesterase type 5 inhibitor, KJH-1002, has an augmentative effect on penile erection comparable to that of sildenafil and can be useful for the treatment of erectile dysfunction.

• Korean Journal of Construction Engineering and Management
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• v.5 no.5 s.21
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• pp.183-192
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• 2004

Even in Korea the number of steel structure buildings that allow internal space and easy change of their layouts in accordance with the purpose of buildings and box-type steel bridges constructed with thick plates with thickness in a rage just from a few $\beta$AE to \$100\beta$AE is increasing these days and therefore, domestic fabrication and processing technology of members for steel structures is being improved at a pace faster than in the past to meet the growing requirements of consumers for high reliability on quality control on the related steel structures. However, most domestic fabricators os steel structures who are turning out their steel products in accordance with the designs prepared by engineering companies in their respective works for the sake of cost cut more than anything else, hesitating to introduce any advanced new technology into themselves. In the case of the steel structure design application for small and mid-size buildings in particular, it is quite meaningful not only for those who are involved in steel structure business, but also for the people working at construction work fields to review the result of the study on the connections of steel structure members deigned to obtain superb quality of steel structures within short period for steel fabrication and erection at fields in economical ways, as there is a glowing tendency seeking standardization of connection of steel structure members as well as whole structure together with the development on design of construction system of buildings including their exterior and interior decoration materials, manufacture of the related members and fabrication technique structure. This paper has been prepared with the aim to review the peculiar characteristics of buildings constructed with the main frames of steel structures and actual cases of the change made ing the connections between steel structure columns and between columns and girder members in order to reduce the work period necessary for fabrication and erection of steel structures at the maximum as well as the some examples of steel structures fabricated through automatic welding by robots for box-type columns in addition to the description of the problems found in the course of fabricating those steel structures, suggesting possible counter-measures to solve them.

• Korean Journal of Construction Engineering and Management
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• v.15 no.3
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• pp.128-135
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• 2014

This paper studied design of slip form system considering the erection of a pylon mock-up. The height of the pylon is 10 m. A rectangular hollow cross-section was considered. The outer and inner dimensions of the pylons were varied with respect to the height. The thickness of 1 sides among the 4 faces were varied. Accordingly the slip form was designed to respond to continuous changes in its dimensions and thickness. Structural analysis was conducted to examine structural safety of the slip form. Virtual construction by BIM proved its practicality. The developed design technologies were successfully applied to the erection of a 10m high pylon executed for field verification test.