• Applied Chemistry for Engineering
• /
• v.28 no.4
• /
• pp.427-431
• /
• 2017

Recently, complaints of floor noise have been growing up with the rapid increase of the residential buildings. This demands the effective floor noise isolation system. Since the construction of high-rise the residential buildings will be increased even more in future, the noise isolation is a more important technology in the market. In this study, a new floor noise isolation panel (FNIP) was designed and manufactured using waste rubbers. The noise isolation was investigated at both laboratory and field conditions. Light and heavy weight shock wave showed 52 dB and 48 dB in the field test, respectively. The new system could reduce the total floor thickness by 22~42 mm.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1998.04a
• /
• pp.371-376
• /
• 1998

As the requirement of high-rise buildings in big cities increases, steel structural system becomes more popular in spite of the relatively higher material cost compared to that of the concrete structural system. Most of the steel structure adopts metal deck floor system because of the easiness in construction. However, the metal deck floor system has a weakness on vibration which became very important factor in office buildings, hotels and residential buildings as the more sensitive machines being used. Therefore, most, of the building codes in many countries restrict the natural frequency of the each floor should be higher than or equal to 15 Hz. Floor vibration of the KEM deck composite floor system which has been , developed recently from the engineers and scientists in Korea was measured. Also, the simplified analytical derivation of natural frequency for each floor was studied according to the measured natural frequency for each different boundary condition of the floor. As the length of the slab gets bigger, the natural frequency of the slab becomes lower even though the structural designer still considers it as a one-way slab.

• International Journal of High-Rise Buildings
• /
• v.3 no.1
• /
• pp.9-19
• /
• 2014

In this study the seismic performances of reinforced concrete apartment buildings with Y- and box-shaped plans having central core are investigated. Three types of model structures are designed for each shape depending on the amount of shear partition walls: structures with all shear walls, structures with all columns except the core walls, and structures with shear walls and columns combined. The required amount of concrete to satisfy the specified design loads is the largest in the all shear wall structures, and decreases as more and more shear walls are replaced with columns. The amount of re-bars increased significantly in the flat plate structures. According to nonlinear static and dynamic analysis results, the structures with all shear walls and all columns turn out to have the largest and the smallest strengths, respectively. However it is observed that even the all-column structures with shear core have proper load resisting capacity for design level seismic load.

• International Journal of High-Rise Buildings
• /
• v.1 no.3
• /
• pp.229-235
• /
• 2012

In this paper the progressive collapse potential of building structures designed for real construction projects were evaluated based on arbitrary column removal scenario using various alternate path methods specified in the GSA guidelines. The analysis model structures are a 22-story reinforced concrete moment frames with core wall building and a 44-story interior concrete core and exterior steel diagrid structure. The progressive collapse resisting capacities of the model structures were evaluated using the linear static, nonlinear static, and nonlinear dynamic analyses. The linear static analysis results showed that progressive collapse occurred in the 22-story model structure when an interior column was removed. However the structure turned out to be safe according to the nonlinear static and dynamic analyses. Similar results were observed in the 44-story diagrid structure. Based on the analysis results, it was concluded that, compared with nonlinear analysis procedures, the linear static method is conservative in the prediction of progressive collapse resisting capacity of building structure based on arbitrary column removal scenario.

• Journal of the Korean Society for Precision Engineering
• /
• v.30 no.4
• /
• pp.390-396
• /
• 2013

Due to the development of technology, there is a considerable increase in the number of skyscrapers in the world. Accordingly, there are rapid growing requests about maintenances such as cleaning, painting, and inspection. However, it is extremely dangerous working the walls of buildings, and crashes from buildings have accounted for large proportion of constructional accidents. Especially, as the number of buildings with irregular shapes increases, the accident rate during the maintenance work increases each year, and most of the accidents lead to death. An alternative solution must be developed with the commercialization of automatic systems. In this research, a fundamental research has been conducted for drafting and commercializing an automation tool that is carried in the built-in guide system, which can perform cleaning.

• International Journal of High-Rise Buildings
• /
• v.2 no.3
• /
• pp.171-178
• /
• 2013

The emergence of a growing number of tall buildings, often with unusual shapes and innovative structural systems, has led to the realization of the need for and the importance of field measurements. The new China Central Television (CCTV) Tower in Beijing is one of tall buildings with a highly unusual shape and a complex structural system, requiring field measurements to identify its dynamic characteristics for the subsequent dynamic analysis of the tower under wind excitation, seismic-induced ground motion and traffic-induced ground motion. The structural system and the finite element model of the CCTV Tower are first introduced in this paper. The computed natural frequencies and mode shapes are then presented as a reference for the field measurement. After introducing the arrangement of the ambient vibration measurement, the field measured natural frequencies and damping ratios of the CCTV Tower are presented and the measured natural frequencies are finally compared with the computed ones. It was found that the structural damping ratios of the CCTV Tower are small and the computed natural frequencies are smaller than the measured ones by about 12~17%.

• International Journal of High-Rise Buildings
• /
• v.3 no.4
• /
• pp.285-296
• /
• 2014

The objective of optimization is to present a design process that minimizes the total material consumption while satisfying current codes and specifications. In the research an optimization formulation for RC shear wall structures is proposed. And based on conceptual design methodology, an optimization process is investigated. Then optimal design techniques and specific explanations are introduced for residential buildings with shear wall structure, especially for that with a rectangular layout. An example of 30-story building is presented to illustrate the effectiveness of the proposed optimal design process. Furthermore, the influence of aspect ratio on the concrete consumption and the steel consumption of the superstructure are analyzed for this typical RC shear wall structure; and their relations are obtained by regressive analysis. Finally, the optimal material consumption is suggested for the residential building with RC shear wall structure and with rectangular layout. The relation and the data suggested can be used for guiding the design of similar RC shear wall structures.

• International Journal of High-Rise Buildings
• /
• v.1 no.4
• /
• pp.283-300
• /
• 2012

Wind-induced vibrations of buildings can be perceived when movement of objects caused by the vibration is seen. However, movement of objects that would normally be expected to trigger visual perception of building vibrations is not necessarily seen in actual building environments. Therefore, to evaluate habitability to building vibrations, it is necessary to examine the influence of movement of objects on vibration perception taking into account probability of seeing the objects. As the first step in this study, those data necessary to estimate probability of vibration perception from seeing of swaying objects have been measured during normal activities in actual buildings. In addition, statistical analysis of the data has also been carried out. As the second step in this study, the probability distribution of vibration perception by visual sensation is estimated using the series of data measured in the first step. Probability of seeing object is considered in the estimated probability distribution.

• KIEAE Journal
• /
• v.6 no.3
• /
• pp.35-42
• /
• 2006

The apartment buildings now covers more than 50% of the total residential types in Korea and the urban residential area becomes increasingly congested with newly constructed high-rise apartment buildings. Judicial precedents require, for securing the solar rights in the residential area, that the consecutive sunshine duration should be at least two hours from 9:00 to 15:00 or the accumulative sunshine duration should be at least four hours from 8:00 to 16:00 as of the winter solstice. Disputes are increasing, however, on infringed solar rights and view rights for the neighboring structures as cases occur where the requirement cannot be satisfied in congested residential areas. The sunshine duration scan be assessed by measuring it on the site of the dispute, but it is impracticable to actually measure it for every case on the winter solstice, only one day out of the whole year. At a trial, therefore, 3D computer simulation is used to calculate the sunshine duration and determine the extent of infringement for submission of the evaluation to be used as the basis of the judgment. The simulation, however, may have an error in its result up to the program characteristics and the accuracy of the input data such as the structure shape and height, the distance between structures, and the ground level. This study, therefore, used a self-developed VIEW program with Autodesk VIZ 2006 to provide a simulation method for solar access evaluation, and verified its efficacy by comparing the results with the actual measurements.

• Structural Engineering and Mechanics
• /
• v.41 no.3
• /
• pp.313-337
• /
• 2012

A three-dimensional formulation is proposed to analyze the lateral loading distribution of external actions in high-rise buildings. The method is extended to encompass any combination of bracings, including bracings with open thin-walled cross-sections, which are analyzed in the framework of Timoshenko-Vlasov's theory of sectorial areas. More in detail, the proposed unified approach is a tool for the preliminary stages of structural design. It considers infinitely rigid floors in their own planes, and allows to better understand stress and strain distributions in the different bearing elements if compared to a finite element analysis. Numerical examples, describing the structural response of tall buildings characterized by bracings with different cross-section and height, show the effectiveness and flexibility of the proposed method. The accuracy of the results is investigated by a comparison with finite element solutions, in which the bracings are modelled as three-dimensional structures by means of shell elements.