• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.20 no.6
• /
• pp.699-708
• /
• 2007

Reinforced concrete deep beams are general structural members used as transfer-girder, pile cap, foundation wall and so on. They have a complex stess formation. Generally, failure mechanisms differ from either continuous deep beams or simple supported deep beams. In continuous deep beams, a negative moment is occurred over intermediate support and the location of maximum moment coincide with high shear force. Therefore, failure usually occurs at this region. While on the other hand, in simple supported deep beam, the region of high shear coincides with the region of low moment. The web opening of deep beams for accepting a facility makes shear behaviors of deep beams more complex and gives rise to an expansion of crack around the opening and a decline of shear capacity of deep beams. Therefore, Engineers must determine a delicate reinforcement method to control a crack and increase a shear capacity. The purpose of this report is a computation of an effective reinforcement method through non-linear finite element method by means of adopting various reinforcement method as variables and a computation of shear capacity formula taking an effectiveness of reinforcement into consideration.

• Earthquakes and Structures
• /
• v.9 no.2
• /
• pp.281-303
• /
• 2015

The effects of infill panels on the response of r.c. frames subjected to seismic action are widely recognized. Numerous experimental investigations were effected and several analytical models were developed on this subject. This work, which is part of a larger project dealing with specific materials and structures commonly used in Italy, discusses experimental tests on masonry and samples of bare and infilled portals. The experimental activity includes tests on elemental materials, and 12 wall samples. Finally, three one-bay one-story reinforced concrete frames, designed according to the outdated Italian technical code D.M. 1996 without seismic details, were tested (bare and infilled) under constant vertical and cyclic lateral load. The first cracks observed on the framed walls occurred at a drift of about 0.3%, reaching its maximum capacity at a drift of 0.5% while retaining its capacity up to a drift of 0.6%. Infill contributed to both the stiffness and strength of the bare reinforced concrete frame at small drifts thus improving overall system behavior. In addition to the experimental activities, previously mentioned, the recalibration of a model proposed by Comberscue (1996) was evaluated. The accuracy of an OpenSees non linear fiber based model of the prototype tested, including a strut element was verified through a comparison with the final experimental results. This work has been partially supported by research grant DPC-ReLUIS 2014.

• Computers and Concrete
• /
• v.31 no.4
• /
• pp.337-348
• /
• 2023

Shear wall is commonly used as a lateral force resisting system of concrete mid-rise and high-rise buildings, but it brings challenges in providing relatively large space throughout the building height. For this reason, the structure system where the upper structure with bearing, non-bearing and/or shear walls that sits on top of a transfer plate system supported by widely spaced columns at the lower stories is preferred in some regions, particularly in low to moderate seismic regions in Asia. A thick reinforced concrete (RC) plate has often been used as a transfer system, along with RC transfer girders; however, the RC plate becomes very thick for tall buildings. Applying the post-tensioning (PT) technique to RC plates can effectively reduce the thickness and reinforcement as an economical design method. Currently, a simplified model is used for numerical modeling of PT transfer plate, which does not consider the interaction of the plate and the upper structure. To observe the actual behavior of PT transfer plate under seismic loads, it is necessary to model whole parts of the structure and tendons to precisely include the interaction and the secondary effect of PT tendons in the results. This research evaluated the seismic behavior of shear wall-type residential buildings with PT transfer plates for the condition that PT tendons are included or excluded in the modeling. Three-dimensional finite element models were developed, which includes prestressing tendon elements, and response spectrum analyses were carried out to evaluate seismic forces. Two buildings with flat-shape and L-shape plans were considered, and design forces of shear walls and transfer columns for a system with and without PT tendons were compared. The results showed that, in some cases, excluding PT tendons from the model leads to an unrealistic estimation of the demands for shear walls sit on transfer plate and transfer columns due to excluding the secondary effect of PT tendons. Based on the results, generally, the secondary effect reduces shear force demand and axial-flexural demands of transfer columns but increases the shear force demand of shear walls. The results of this study suggested that, in addition to the effect of PT on the resistance of transfer plate, it is necessary to include PT tendons in the modeling to consider its effect on force demand.

• Journal of the Korean Institute of Rural Architecture
• /
• v.20 no.4
• /
• pp.65-75
• /
• 2018

This thesis attempts to investigate and analyse the architectural characteristics of catholic churches in Gangwon province built in the 1950s. Catholic churches built at that time in Korea had many similarities basically since they were supported by UN forces after the Korean War and were established by priests connected to the Missionary Society of St. Columban. The results of study are as follows. In location, Except one catholic church, the catholic churches preferred low and gentle hill. In layout axis, catholic churches at Youngseo area preferred the north-south layout axis, whereas those at Youngdong favor the east-west layout axis. In approach, most of catholic churches around the Youngseo and Youngdong areas preferred entering the front entrance with a bell tower, whereas three of them at Youngdong did entering the front entrance with a bell tower around the rear corner. In floor plan, catholic churches at Youngseo preferred symmetry, whereas those at Youngdong preferred asymmetry. And every floor plan of catholic churches is rectangular type with transepts except one semicircular type. In apse shape, catholic churches in the Youngseo area preferred non-extruded types like a straight wall, whereas those in Youngdong have extruded types. Every catholic churches have no crypt under ground except one at Gangreung. Except one at Sokcho, every catholic church in this study has choir space in half story.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.22 no.6
• /
• pp.415-422
• /
• 2010

Development of the reliability-based design program in the GUI environment is inadequate for engineers familiar with the deterministic design to deal with the international design criterion based on the probabilistic design. In this study, the design program based on the GUI environment is developed in order to more efficiently input the design factor and more easily carry out the design works. The GUI environment is the GUIDE (Graphic User Interface Development Environment) tool supported by the latest MATALB version 7.1. In order to test the model reliability, the probabilities of failure (POF) on the breakwater armor block (AB) and gravity quay-wall (QW) in the sliding mode are computed using the model in the Level II and Level III. The POF are 55.4~55.7% for breakwater AB and 0.0006~0.0007% for gravity QW. A non-GUI environment program results of the POF are 55.6% for breakwater AB and 0.0018% for gravity QW. In comparison, the POF difference is negligible for breakwater AB because the exact input design parameters are available, whereas the large POF difference, but within the same order, for gravity QW can be explained by the difference of the input design factors because of the poor input data information.

• Journal of the Korean Geosynthetics Society
• /
• v.14 no.4
• /
• pp.87-96
• /
• 2015

Geosynthetics are widely used in different ways such as reinforcement of structures in road, railway, harbor and dam engineering, drainage, separation and erosion prevention. They are especially applied to reinforced retaining wall and slope or ground reinforcement. Recently, geosynthetics reinforced pile supported (GRPS) embankment was developed to improve stability and construability of embankments in railway engineering. Extension strains are usually measured by strain gauges adhered to geosynthetics to evaluate the stability of geosynthetics. However, the measurements are influenced by manufacturing method and stiffness of geosynthetics and also adherence of strain gauge. In this study, wide-width tensile strength tests were performed on three types of geosynthetics including geogrid, woven geotextile and non-woven geotextile. During the test, strains of geosynthetics were measured by both video extensometer and strain gauges adhered to the geosynthetics and the measured results were compared. Results show that the measured results by strain gauges have high reliability in case of large stiffness geosythetics like geogrid and woven geotextile, whereas they have very low reliability for small stiffness geosythetics like non-woven geotextile.

• The Korean Journal of Air & Space Law and Policy
• /
• v.28 no.2
• /
• pp.349-384
• /
• 2013

The Sputnik 1 launching in 1957 made the world recognize the necessity of international regulations on space development and activities in outer space. The United Nations established COPUOS the very next year, and adopted the mandate to examine legal issues concerning the peaceful uses of outer space. At the time, the military sector of the U.S.A. and the Soviet Union were in charge of the space development and they were not welcomed to discuss the prohibition of the military uses of outer space at the legal section in the COPUOS. Although both countries had common interests in securing the freedom of military uses in outer space. As the social and economic benefits derived from space activities have become more apparent, civil expenditures on space activities have continued to increase in several countries. Virtually all new spacefaring states explicitly place a priority on space-based applications to support social and economic development. Such space applications as satellite navigation and Earth imaging are core elements of almost every existing civil space program. Likewise, Moon exploration continues to be a priority for such established spacefaring states as China, Russia, India, and Japan. Recently, Companies that manufacture satellites and ground equipment have also seen significant growth. On 25 February 2012 China successfully launched the eleventh satellite for its indigenous global navigation and positioning satellite system, Beidou. Civil space activities began to grow in China when they were allocated to the China Great Wall Industry Corporation in 1986. China Aerospace Corporation was established in 1993, followed by the development of the China National Space Administration. In Japan civil space was initially coordinated by the National Space Activities Council formed in 1960. Most of the work was performed by the Institute of Space and Aeronautical Science of the University of Tokyo, the National Aerospace Laboratory, and, most importantly, the National Space Development Agency. In 2003 all this work was assumed by the Japanese Aerospace Exploration Agency(JAXA). Japan eases restrictions on military space development. On 20 June 2012 Japan passed the Partial Revision of the Cabinet Establishment Act, which restructured the authority to regulate Japanese space policy and budget, including the governance of the JAXA. Under this legislation, the Space Activities Commission of the Ministry of Education, Culture, Sports, Science, and Technology, which was responsible for the development of Japanese space program, will be abolished. Regulation of space policy and budget will be handed over to the Space Strategy Headquarter formed under the Prime Minister's Cabinet. Space Strategy will be supported by a Consultative Policy Commission as an academics and independent observers. By revoking Article 4 (Objectives of the Agency) of a law that previously governed JAXA and mandated the development of space programs for "peaceful purposes only," the new legislation demonstrates consistency with Article 2 of the 2008 Basic Space Law. In conformity with the principles laid down in the 1967 Outer Space Treaty JAXA is now free to pursue the non-aggressive military use of space. New legislation is the culmination of a decade-long process that sought ways to "leverage Japan's space development programs and technologies for security purposes, to bolster the nation's defenses in the face of increased tensions in East Asia." In this connection it would also be very important and necessary to create an Asian Space Agency(ASA) for strengthening cooperation within the Asian space community towards joint undertakings.