In the years to come, Korea will have the privilege to become the country presenting the most diversified bridge construction activities that will constitute precious case studies for the international bridge community. Until 2011, about 50 major bridges with various types will link some of the 3,000 islands of the peninsula to the mainland, which are taking place in the ambitious plan for building an efficient national transportation network and set the bases for the future strategic hub of Northeast Asia. In order to sustain this unprecedented construction activity of infrastructure systems and the encouraging technological accomplishments that have been acquired to date, the Korean R&D community agreed with the necessity to prepare for the next generation of construction technology. There is a clear need to develop and construct a new generation of high performance facilities by means of enhanced materials, advanced structural systems and technologies as well as upgraded or improved specifications or standards in a lifetime perspective. This paper identifies some major technical issues and challenges for the next generation of bridge and addresses relevant and systematic construction-related R&D programs in Korea. Among them, the Korea Bridge Design & Engineering Research Center (KBRC) has been launched in 2004 as a national research program of the Ministry of Construction and Transportation to be the core of new research and technology transfer program in the area of bridge technology and expedite the process of full transition to the reliability-and performance-based bridge design codes and specifications in Korea. Other large R&D programs are also reviewed in terms of durability and lifecycle cost with lifetime perspective like the Bridge 200 R&D project of the Korea Institute of Construction Technology and high-performance materials like the High Performance Construction Material Research Center (HIPER CONMAT).
This study describes an analytical proposal to predict lateral shear capacity of confined masonry walls that fail by diagonal splitting, where the maximum shear is evaluated as the dowel action of confined columns' reinforcement added to the shear capacity of the plain masonry panel. In order to validate the proposed approach, experimental test results and gathered data from literature were used. The experimental tests concerned two confined clay brick walls subjected to different level of gravity load and cyclic lateral loading. The applicability of some empirical formulae found in literature regarding the stiffness degradation was investigated. Good correlation between the predicted lateral resistance using the proposed approach and all data was achieved.
In this study, the mechanisms associated with the seismic response of a long-period structure when subjected to a long-period seismic excitation are clarified. A typical scale cable-stayed bridge with prestressed concrete girders (PC cable-stayed bridge) was selected for analysis. First, we simulated long-period components of the ground motion at the site of the Ji-Lu Bridge, which was damaged in the 1999 Chi-Chi, Taiwan earthquake, and the damage of the bridge was assessed by nonlinear seismic analysis using the simulated ground excitations. Second, shaking table tests of a model PC cable-stayed bridge were carried out, in consideration of the similarity law, to clarify the mechanisms involved, focusing on the linear and nonlinear seismic responses of the tower and cables.
XFEMにおいて生じる構成する節点が部分的にエンリッチされた要素であるBlending Elements (BE) は，PU条件を満足しないことから，その内部において近似精度が低下する．そこで，本研究ではXFEMが特に有効であるき裂解析を対象として，まずき裂先端近傍に生じるBEの解析精度への影響を評価し，BEとJ積分法に基づいた破壊力学パラメータの解析精度に関する因果関係を明確にした．さらにこの結果を基に，BEの直接的な影響を容易に回避できる，J積分経路およびエンリッチメントに関するモデル化の提案を行った．本提案を用いて解析を行った結果，最小範囲のエンリッチメントにより，従来の方法と比較して十分な精度で解析できることが明らかとなった．