• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.194-195
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• 2021

Due to urban regeneration projects or changes in the living environment, there is an increasing need to demolish old buildings that have lost their functions. Demolition of above ground and underground structures is an important construction project that greatly affects the construction period and safety of the entire process. However, it is difficult for the safety officer to manage the demolition work due to the lack of specific and diverse data applicable to the site of the demolition plan. Therefore, in this study, items that need to be improved in structural safety when the above-ground and underground structures are demolished are reviewed and organized. For the main contents of structural safety management in demolition work, 1) structural review reflecting the order of demolition work, 2) installation and dismantling of steel pipe scaffolding and dust nets, 3) installation and dismantling of system scaffolding, 4) installation and dismantling of fall prevention nets, 5) jack support Installation and dismantling, 6) movement of equipment, movement and planning between floors, 7) equipment for demolition of structures, height of remnants, 8) site cleanup, and 9) equipment operators were categorized and arranged.

• Structural Monitoring and Maintenance
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• v.11 no.2
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• pp.87-100
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• 2024

Traffic-induced vibrations (TIVs) possess the potential to induce structural damage in both historical and critical edifices. Recent investigations have underscored the adverse impact of TIVs within buildings, manifesting as a deleterious influence on the quality of life and operational efficiency of occupants. Consequently, these studies have dichotomized TIVs into two primary limit categories: the threshold for vibrations capable of causing structural damage and the limit values associated with human comfort. In this current research endeavor, an exhaustive analysis of peak ground acceleration (PGA), peak ground velocity (PGV), peak ground displacement (PGD), and the frequency spectrum of ground motions originating from diverse traffic sources has been conducted. Furthermore, the detrimental repercussions of these vibrations on structures, gauged through the assessment of the peak particle velocity (PPV) parameter, have been systematically evaluated. The findings of this study elucidate that TIVs within the examined structures do not attain magnitudes conducive to structural compromise; however, the levels surpassing human comfort limits are evident, attributable to specific sources and distances. Moreover, this investigation sheds light on the absence of comprehensive criteria and guidelines pertaining to the assessment of TIVs in structures within the Turkish Building Seismic Design Code 2018. It seeks to raise awareness among building constructors about the critical importance of addressing this issue, emphasizing the imperative for guidelines in mitigating the impact of TIVs on both structural integrity and human well-being.

• Journal of the Earthquake Engineering Society of Korea
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• v.15 no.5
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• pp.25-33
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• 2011

In the nonlinear response history analysis of building structures, the input ground accelerations have considerable effect on the nonlinear response characteristics of structural systems. As the properties of the ground motion, using time history analysis, are interrelated with many factors such as the fault mechanism, the seismic wave propagation from source to site, and the amplification characteristics of the soil, it is difficult to properly select the input ground motions for seismic response analysis. In this paper, the most unfavourable real seismic design ground motions were selected as input motions. The artificial earthquake waves were generated according to these earthquake events. The artificial waves have identical phase angles to the recorded earthquake waves, and their overall response spectra are compatible with the seismic design spectrum with 5% of critical viscous damping. It is concluded that the artificial earthquake waves simulated in this paper are applicable as input ground motions for a seismic response analysis of building structures.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.3C
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• pp.121-127
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• 2012

This paper investigates the response of frame structures with the consideration of tunnel construction (ground loss) conditions. The response of four-story open frame structure and block-infilled frame structures, which are subjected to tunnelling-induced ground movements, has been investigated in different construction (ground loss) conditions using numerical analysis. The open frame structure has been modelled as an elastic structure, while the block-infilled frame structure has been modelled to have real cracks when the shear and tensile stress exceed the maximum shear and tensile strength. The response of the two different frame structures has been investigated in terms of construction (ground loss) conditions considering the magnitude of deformations and cracks in structures. In addition, the damage levels, which are possibly induced in the structures, has been provided in terms of construction (ground loss) conditions using the state of strain damage estimation criterion (Son and Cording, 2005). The results of this study will provide a background for better understandings for controlling and minimizing building damage on nearby frame structures due to tunnelling-induced ground movements.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.230-233
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• 2006

Conventionally, it used to be focused on simply prevention of further settlement of structures, where, much of problems were raised and sometimes the construction itself was not possible. Further, rough estimation of the ground, which is unseen, often incurred many troubles in the maintenance. D-ROG method is a high-tech technology that changes almost all of the concepts on the conventional grouting, is expanding its application scope spanning from the restoration of settled structures to ground strengthening works necessary for building enlargement and remodeling.

• Proceedings of the Korean Society for Language and Information Conference
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• 2007.11a
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• pp.29-41
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• 2007

Concepts of greater and greater complexity can be constructed by building systems of entities, by relating other entities to that system with a figure-ground relation, by embedding concepts of figure-ground in the concept of change, by embedding that in causality, and by coarsening the granularity and beginning the process over again. This process can be called the Ontological Ascent. It pervades natural language discourse, and suggests that to do lexical semantics properly, we must carefully axiomatize abstract theories of systems of entities, the figure-ground relation, change, causality, and granularity. In this paper, I outline what these theories should look like.

• Earthquakes and Structures
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• v.15 no.2
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• pp.179-191
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• 2018

This study is aimed at investigating the dynamic performance of a composite building structure under seismic ground motions. The building structure is an official fire department building located in southern Taiwan. It is composed of a seven-story reinforced concrete (RC) and an eight-story steel reinforced concrete (SRC) frame. Both frames share a common basement and are separated by expansion joints from the first to the seventh floor. Recorded floor accelerations of the building structure under eight earthquakes occurring during the period from 2011 to 2013 were examined in this paper. It is found that both frames had similar floor acceleration amplifications in the longitudinal direction, while the SRC frame revealed larger response than the RC frame in the transverse direction. Almost invariant and similar fundamental periods under the eight earthquakes in both directions were obtained from their transfer functions. Furthermore, numerical time-history simulations were carried out for the building structure under the most intensive earthquake. It is realized that the seismic response of the composite building was dominated by the first translational mode in each horizontal direction. Higher modes did not significantly contribute to the structural response. The conventional Rayleigh damping model could be appropriately applied to the time-history simulations under bi-directional excitations. Approximate floor acceleration envelopes were obtained with a compound RC and SRC structural model by using the average damping ratios determined from the different structural arrays.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.692-697
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• 2006

The importance about the maintenance consideration of the building has a great impact and regarding the life continuation of the building the many interest is becoming intensively. The housing lot of the heart of urban at the capital region has insufficient recently and the construction of the ground complex building in solution for the insufficiency is increasing at the rapid pace. The ground complex building is brings the maximization of land use from inside the site, but maintenance consideration phase is caused by administration cost share and administration bound limit where person is concerned for a many problem point it contains. The objective of the present paper is that the building is maintain an efficiency initially and is improve in order to develop guide line for a maintenance consideration improvement from design phase. According as literature research and question research is enforce, the paper is escape problem point the maintenance consideration and is bring up guide line for the architectural plan field and the maintenance consideration improvement of the building. Result of the study is expected a help in maintenance consideration improvement during life cycle of the building

• Journal of the Korean Geotechnical Society
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• v.15 no.4
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• pp.19-42
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• 1999

In urban area, there are several major factors to be considered in tunnel design and construction. The first is to predict the magnitude and distribution of ground movements for particular ground conditions and construction procedures. The second is to assess the potential damage to nearby structures in response to the predicted ground movements. The third is to select the measures to be taken if a potential damage is foreseen. This study is concerned primarily with the first and second stages of the problem. Particularly, this paper is focused on the second stage to assess the potential damage to the nearby building with any type of geometries and locations above ground surface. In order to solve this problem, we introduced damage parameters(angular distortion, deflection ratio, maximum building settlements, maximum differential settlements, horizontal strain, etc.), and extended these parameters into 3-dimensional safety assessment. Also, to assess the safety of any walls existing in the building, we developed a 3-dimensional analysis program, and various parametric studies for the nearby building with any type of geometries and locations were presented. In addition to these parametric studies, we compared the results of the proposed techniques with some abroad case records for particular tunnels and adjacent buildings.

• Geotechnical Engineering
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• v.14 no.2
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• pp.107-126
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• 1998

Ground settlements induced by tunnel excavation cause the foundations of the neighboring building structures to deform. An expert system called NESASS( Neural network Expert System for Adjacent Structure Safety analysis) was developed to analyze the structural safety of such building structures. NESASS predicts the trend of ground settlements resulting from tunnel excavation and carries out a safety analysis for building structures on the basis of the predicted ground settlements. Using neural network technique. the NESASS learns the database consisting of the measured ground settlements collected from numerous actual fields and infers a settlement trend at the field of interest. The NESASS calculates the magnitudes of angular distortion, deflection ratio, and differential settlement of the structure. and in turn, determines the safety of the structure. In addition, the NESASS predicts the patterns of cracks to be formed in the structure, using Dulacska model for crack evaluation. In this study, the ground settlements measured from Seoul subway construction sites were collected and classified with respect to the major factors influencing ground settlement. Subsequently, a database of ground settlement due to tunnel excavation was built. A parametric study was performed to select the optimal neural network model for the database. A comparison of the ground settlement predicted by the NESASS with the measured ones indicates that the NESASS leads to reasonable predictions. The results of confidence evaluation for safety evaluation system of the NESASS are presented in this paper.