• Journal of Korean Tunnelling and Underground Space Association
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• v.6 no.4
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• pp.345-356
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• 2004

Open-cut method has been widely used to construct underground structures, but it causes several problems such as traffic congestion and public resentment resulting from severe construction noise and ground settlement. In many cases, it is very difficult to build underground structures safely due to the unknown locations of buried facilities such as water pipes, drainage pipes, gas pipes and high-pressure cable conduits etc. Also in open-cut method, moving buried facilities causes additional cost and extension of construction period. Therefore, this paper is to present a case study in which Tubular Roof construction Method (T.R.c.M.), a newly developed construction method for underground structures using slab steel pipes and PC wall trench, is applied for the construction of a subway tunnel in Seoul. As a result, it is found that T.R.c.M. is a construction method by which tunnels can be constructed safely without any effect on the surrounding environment and traffic flow due to the minimized construction vibration and noise.

• Korean Journal of Construction Engineering and Management
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• v.9 no.6
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• pp.147-155
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• 2008

In the 1970s, increasing penetration of the housing co-housing policy, reconstruction be a great success to improve 1990‘s Old aged apartment's performance. However, in case of reconstruction, it causes the problem such as city environment destruction, resource waste, real-estate speculation etc. With the trend of sustainable construction and resource recycling, remodeling gets more attention than before. In case of country's remodeling, conventional method causes some problems such as delayed construction period and increased cost. Therefore, efforts that obtain economical efficiency are required to power remodeling through use of prefabrication method like PC technology that is useful for reduction effect of construction period, cost and site labor and excellent quality. This research indicates reduceing factor for facilitating prefabrication method and technology selecting framework through specific of Expanding Floor method and remodeling cases to increase the efficiency of remodeling, considers construction parties approaching plan for prefabrication as occasion that powers remodeling.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.113-118
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• 2007

In this study, we select a site adopting real composite precast concrete method. Estimating real construction cost and imaginary cost appling reinforced concrete method in the site, we compare the costs. Through using high intensity concrete and prestressed concrete, amount of concrete is reduced more than 50% but there isn't big gap in material cost. In the main construction cost of composite precast concrete method, the material cost with production cost and transportation cost are in that, joints and topping concrete are account for 90%. But in case of reinforced concrete, labor cost spent at concrete steel bar and form is account for 30%. In the cost of attached, compared with composite precast concrete method, the reinforced concrete method taken in big portion by temporary work and scaffolding is twice as much as composite precast concrete method in construction cost. Therefore, economic efficiency is excellent reducing 11% total cost of composite precast concrete method from the reinforced concrete method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.05a
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• pp.15-19
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• 2008

The use of Precast Concrete (PC) stairways is increasing to replace existing Reinforced Concrete (RC) stairways for the faster construction and the better quality control. Among several already developed PC stairway construction methods, RC Core Sequential Construction Method by Using PC Stairways (COSEC) has advantages of 1) allowing core of a building to be built prior to PC stairways so that two different procedures will not interfere with each other, and 2) having a newly developed joint connection with the core so that the RC core and PC stairways can be easily put together. In this paper, cases of several construction sites with the PC stairways method are analyzed. The elements of the developed method are described for further application and improvement.

• Journal of the Korean Geotechnical Society
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• v.28 no.1
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• pp.55-66
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• 2012

The load transfer mechanism of hybrid model of soil-nailing and compression anchor is studied in this paper. The hybrid model is composed of an anchor bar (installed at the tip) with two PC strands and a steel bar. It can make active behavior of skin friction by applying the pre-stress. In this paper, the load transfer mechanisms of soil-nailings, compression anchors, and hybrid models, respectively, are obtained from skin friction theory and load transfer theory. Field pullout tests are performed to identify the load transfer mechanism and experimental results are compared with analytical solution. In case of soil-nailings, the tension load is transferred from face to tip, however, in case of compression anchors, the compression load is transferred from tip to face. The experimental behavior of the hybrid model is similar to that of compression anchor when only pre-stress is applied. If the pullout test is performed by simultaneously pulling out the anchor and the nail, the compression load is dominant at the tip and tension load is dominant at the face. The load transfer mechanism of the hybrid model shows the combined behavior of soil-nailings with compression anchors.

• Korean Journal of Construction Engineering and Management
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• v.13 no.3
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• pp.34-42
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• 2012

Green frame technology intended to facilitate the remodeling of apartment housing complexes in Korea and extend their service life has been developed. Green frame design is a Rahmen structure using composite precast concrete members and, unlike a bearing-wall structure, lifting and installing structural members accounts for major steps of structural construction. Therefore, if green frame structure construction is to be scheduled appropriately, systematic lifting plan needs to be developed in advance. Development of lifting plan also requires unit lifting process of composite PC members (columns and beams) that consist of green frame to be analyzed first. Therefore, this study attempts to analyze the lifting process of composite PC members used in green frame structure. To that end, lifting procedure and time of composite PC column and beam are estimated and applied to a project case to analyze the lifting cycle of reference floor. Outcomes produced herein will be used as key data for development of lifting plan in subsequent green frame structure construction.

• 지반과기술
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• v.4 no.1
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• pp.85-92
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• 2007

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.6
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• pp.417-426
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• 2021

Recently, use of the precast concrete (PC) system, which can increase economy by minimizing field work, has rapidly increased. However, the PC system cannot exhibit structural performance under construction, specifically before integration between members. Furthermore, since it is difficult to secure the structural integrity of beam-column joints even after construction, the PC system is vulnerable to progressive collapse. In the PC system, various types of details for PC beam-column joints have been proposed, while the structural/construction details of PC system generally used in Korea differ from those of overseas PC systems. However, studies on the progressive collapse of the domestic PC system are limited. Thus, in this study, we investigated the structural/construction details of PC beam-column joints mainly used in Korea. Based on the investigation, for the prototype PC system with typical joint details, a nonlinear finite element analysis was carried out to evaluate its structural performance under progressive collapse. Further, a parametric study was performed, and the effect of the design parameters was investigated, to recommend a method to improve the progressive collapse resistance of the PC system.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.459-460
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• 2009

The purpose of this study is to develop precast concrete structural wall panel that can assure reliable seismic performance. In the previous study, the connection of precast concrete structural wall has some problems in seismic performance. Therefore, this research proposed the precast concrete structural walls which can improve seismic performance. And their seismic performance was verified through lateral loading experiment.

• Proceedings of the Korean Geotechical Society Conference
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• 1992.06a
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• pp.57-86
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• 1992

본 연구에서는 기존의 PC말뚝과 PHC말뚝의 시공성과 지지력에 대한 비교확인 시험의 결과를 근거로 하여 PHC말뚝의 시공상의 장점, 특성 및 경제성을 파악하였으며, SIP공법에 의하여 PHC말뚝을 사용시 기존 PC말뚝이나 강관말뚝보다 경제성이 우수함을 확인하였다. 또한 PHC말뚝은 압축강도와 지지혁이 기존 PC말뚝보다 높을 뿐만아니라 강관말뚝과 같이 용접이음이 가능하고 말뚝의 심도가 깊은 경우에도 강관말뚝과의 대체시공이 가능하여 PHC말뚝의 성능을 극대화할 수 있는 적절한 항타장비를 사용하는 경우에는 혁신적인 원가절감이 가능함을 확인할 수 있다.