• Earthquakes and Structures
• /
• v.16 no.4
• /
• pp.401-413
• /
• 2019

The concept of base isolation for equipment is well known. Its application in buildings and structures is rather challenging. Introduction of horizontal flexibility at the base helps in proper energy dissipation at the base level thus reducing the seismic demand of the super structure to be considered during design. The present study shows the results of a series of numerical simulation studies on seismic responses of secondary system (SS) housed in non-isolated and base-isolated primary structures (PS) including equipment-structure interactions. For this study the primary structure consists of two similar single bay three-store reinforced cement concrete (RCC) Frame building, one non-isolated with conventional foundation and another base isolated with Lead plug bearings (LPB) constructed at IIT Guwahati, while the secondary system is modeled as a steel frame. Time period of the base isolated building is higher than the fixed building. Due to the presence of isolator, Acceleration response is significantly reduced in both (X and Y) direction of Building. It have been found that when compared to fixed base building, the base isolated building gives better performance in high seismic prone areas.

• International Journal of High-Rise Buildings
• /
• v.6 no.3
• /
• pp.227-235
• /
• 2017

This paper describes some of the challenges for structural design of a mid-story seismic isolated high-rise building, which is located near Tokyo station, completed in 2015. The building is a mixed-use complex and encompasses three volumes: one substructure including basement and lower floors, and a pair of seismic isolated superstructures on the substructure. One is a 136.5m high Main Tower (office use), and the other is a 98.5 m high South Tower (hotel use). The seismic isolation systems are arranged in the $3^{rd}$ floor of the Main Tower and $5^{th}$ floor of the South Tower, so that we call this isolation system as the mid-story seismic isolation. The primary goal of the structural design of this building was to secure high seismic safety against the largest earthquake expected in Tokyo. We adopted optimal seismic isolation equipment simulated by dynamic analysis to minimize building damage. On the other hand, wind-induced vibration of a seismic isolated high-rise building tends to be excited. To reduce the vibration, the following strategies were adopted respectively. In the Main Tower with a large wind receiving area, we adopted a mechanism that locks oil dampers at the isolation level during strong wind. In the South Tower, two tuned mass dampers (TMDs) are installed at the top of the building to control the vibration. In addition, our paper will also report the building performance evaluated for wind and seismic observation after completion of the building. In 2016, an earthquake of seismic intensity 3 (JMA scale) occurred twice in Tokyo. The acceleration reduction rate of the seismic isolation level due to these earthquakes was approximately 30 to 60%. These are also verified by dynamic analysis using observed acceleration data. Also, in April 2016, a strong wind exceeding the speed of 25m/s occurred in Tokyo. On the basis of the record at the strong wind, we confirmed that the locking mechanism of oil damper worked as designed.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.20 no.3
• /
• pp.181-190
• /
• 2016

The objective of this study is to apply performance-based seismic design to high-rise apartment buildings in Korean considering collapse prevention level. The possible issues during its application were studied and the suggestions were made based on the findings from the performance-based seismic design of a building with typical residential multi-unit layout. The lateral-force-resisting system of the building is ordinary shear walls system with a code exception of height limit. In order to allow the exception, the serviceability and the stability of the ordinary shear wall structure need to be evaluated to confirm that it has the equivalent performance as the one designed under the Korean Building Code 2009. The structure was evaluated whether it satisfied its performance objectives to withstand Service Level and Maximum Considered Earthquake.

• Journal of the Korean housing association
• /
• v.15 no.4
• /
• pp.35-43
• /
• 2004

The environment pollution is very important problem. Even at the field of architecture, a study about method of saving energy and constructing environment friendly building will have performed with activity. But trends of Korea housing market are changed that the height of building become more higher and the level of comfort going up. Therefore, these requirements force to increase the energy usage for indoor environmental controls. Thus, the purpose of this study is to reduce the heating and cooling energy requirements of High-rise Residential Buildings by the analysis of Energy Performance. From now on, we search improvement plan for the most efficient Energy Saving at present High-rise Residential Buildings.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.05a
• /
• pp.204-205
• /
• 2017

In this study, flowability and strength on ultra high performance concrete(UHPC) pre-mixed binders with fiber was investigated. The flow of UHPC with pre-mixed binders was higher than that of seperate mixing conditions. The UHPC using PVA fiber with high specific surface area showed a low flow compared to steel fiber. An pre-mixing method led to improved strength of UHPC and low deviation of specimens due to dispersion effect of each materials.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.39 no.4
• /
• pp.477-483
• /
• 2019

Recently, precast type SCP modules are being used instead of PSC structures in order to reduce the construction period and costs of special structures such as nuclear power plants and LNG storage tanks. The inside of the SCP module is connected with a stud for the integral behavior of the steel and concrete, and the use of high fluidity concrete is required. High fluidity concrete generally has a high content of binder, which leads to an increase in hydration heat and shrinkage, and a problem of non-uniform strength development. Therefore, in this study, fluidity and passing performance of high fluidity concrete according to material properties are investigated to select optimum mix design of low binder based high fluidity concrete. Mechanical properties of high fluidity concrete before and after pumping are examined using pump car. The filling performance of SCP mock-up members was evaluated by using high fluidity concrete finally.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2005.05a
• /
• pp.179-183
• /
• 2005

In apply roof waterproof system using of synthetic high polymer sheet for rooftop measure physical performance (tension$\cdot$tearing ability, temperature relativity, heating stretch performance, junction performance, wind resistance test) by various test environment condition waterproof test of structure and performance of construction work aspect, present suitable form of construction work under these environment. Also, wish to improve durability of concrete structure as that examine in priority about adhesion method and joint junction method with waterproof out surface, and present new direction about roof system application of waterproofing method for rooftop.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2011.05a
• /
• pp.7-10
• /
• 2011

In this study, evaluation system of impact resistance performance is proposed. Compressive strength of concrete is 40, 60 and 80MPa. It evaluate impact resistance performance to use projectile 6, 7 and 8mm size. As a result, safety performance is more higher when the compressive strength is increased in. Compared with Hughes's formula, evaluation system of impact resistance performance is appropriated.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2014.05a
• /
• pp.286-287
• /
• 2014

Performance degradation of Ultra High Strength Concrete occurs more than that of normal strength concrete at high temperature. Thus, strain of concrete subjected to high temperature and loading is one of the core assessment items for evaluating performance of structures. Therefore, in this study, creep of ultra high strength concrete subjected to various temperature conditions and 25%, 40% loading was evaluated. As the results, Creep strain increased with increase of temperature and loading. Creep strain of concrete at high temperature is influenced by loading.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.10a
• /
• pp.553-556
• /
• 1999

In this dissertation, experimental research was carried out to study the hysteretic behavior of reinforced high-strength concrete beam-column joints designed by high performance techniques, such as application of high-strength concrete, reducing of joint regions damage, moving of beam plastic hinge. Specimens(HJAI, HJCI), designed by the development of earthquake-resistant performance, moving of beam plastic hinge, and new design approach, were attained the moving of beam plastic hinge and developed significantly earthquake-resistant performance of such joints.