• Journal of the Earthquake Engineering Society of Korea
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• v.21 no.1
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• pp.69-76
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• 2017

Seismic analyses of a pile under a large rigid basement foundation embedded in the homogeneous soil layer were performed practically by a response displacement method assuming a sinusoidal wave form. However, it is hard to take into account the characteristics of a large mat foundation and a heterogeneous soil layer with the response displacement method. The response displacement method is relevant to the 2D problems for longitudinal structures such as tunnel, underground cave structure, etc., but might not be relevant with isolated foundations for building structures. In this study, seismic pile analysis by a pseudo 3D finite element method was carried out to compare numerical results with results of the response displacement method considering 3D characteristics of a foundation-soil system which is important for the building foundation analyses. Study results show that seismic analyses results of a response displacement method are similar to those of a pseudo 3D numerical method for stiff and dense soil layers, but they are too conservative for a soft soil layer inducing large soil pressures on the foundation wall and large pile displacements due to ignored foundation rigidity and resistance.

• Geomechanics and Engineering
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• v.14 no.1
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• pp.51-60
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• 2018

The foundations are classified into shallow and deep, which have important differences: in terms of geometry, the behavior of the soil, its structural functionality, and its constructive systems. The shallow foundations may be of various types according to their function; isolated footings, combined footings, strip footings, and slabs foundation. The isolated footings are of the type rectangular, square and circular. The combined footing may be rectangular, trapezoidal or T-shaped in plan. This paper presents a new model for T-shaped combined footings to obtain the most economical contact surface on the soil (optimal dimensioning) to support an axial load and moment in two directions to each column. The new model considers the soil real pressure, i.e., the pressure varies linearly. The classical model uses the technique of test and error, i.e., a dimension is proposed, and subsequently, the equation of the biaxial bending is used to obtain the stresses acting on each vertex of the T-shaped combined footing, which must meet the conditions following: The minimum stress should be equal or greater than zero, and maximum stress must be equal or less than the allowable capacity that can withstand the soil. To illustrate the validity of the new model, numerical examples are presented to obtain the minimum area of the contact surface on the soil for T-shaped combined footings subjected to an axial load and moments in two directions applied to each column.

• Earthquakes and Structures
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• v.8 no.3
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• pp.801-820
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• 2015

The seismic sequence which hit the Northern Italian territory in 2012 produced extensive damage to reinforced concrete (RC) precast buildings typically adopted as industrial facilities. The considered damaged buildings are constituted by one-storey precast structures with RC columns connected to the ground by means of isolated socket foundations. The roof structural layout is composed of pre-stressed RC beams supporting pre-stressed RC floor elements, both designed as simply supported beams. The observed damage pattern, already highlighted in previous earthquakes, is mainly related to insufficient connection strength and ductility or to the absence of mechanical devices, being the connections designed neglecting seismic loads or neglecting displacement and rotation compatibility between adjacent elements. Following the vulnerabilities emerged in past seismic events, the paper investigates the seismic performance of industrial facilities typical of the Italian territory. The European building code seismic assessment methodologies are presented and discussed, as well as the retrofit interventions required to achieve an appropriate level of seismic capacity. The assessment procedure and retrofit solutions are applied to a selected case study.

• Earthquakes and Structures
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• v.18 no.6
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• pp.667-675
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• 2020

The current study compares the effect of structure-soil-structure interaction (SSSI) on the dynamic responses of adjacent buildings and isolated structures including soil-structure interaction (SSI) with the responses of fixed-base structures. Structural responses such as the relative acceleration, displacement, drift and shear force were considered under earthquake ground motion excitation. For this purpose, 5-, 10- and 15-story structures with 2-bay moment resisting frames resting on shallow foundations were modeled as a group of buildings in soft soil media. Viscous lateral boundaries and interface elements were applied to the soil model to simulate semi-infinite soil media, frictional contact and probable slip under seismic excitation. The direct method was employed for fully nonlinear time-history dynamic analysis in OpenSees using 3D finite element soil-structure models with different building positions. The results showed that the responses of the grouped structures were strongly influenced by the adjacent structures. The responses were as much as 4 times greater for drift and 2.3 times greater for shear force than the responses of fixed-base models.

• Geomechanics and Engineering
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• v.32 no.2
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• pp.193-207
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• 2023

In general, the numerous classical approaches available in the literature can anticipate the settlement of shallow foundations. As long as the footings are not in close proximity to other subsurface buildings, the findings achieved using these methods are legitimate and acceptable. However, due to increased urbanisation and land scarcity, footings are frequently built close together. As a result, these footings' settlement behaviour differs from those of isolated footings. A simpler approach for assessing the settlement behaviour of two square or rectangular footings placed in close proximity is presented in this work. A Parametric study has been carried out to examine the interference effect on the settlement of these footings placed in close vicinity on the surface of a homogeneous, isotropic and elastic soil medium. The interaction factors are examined by varying the different aspect ratios (L/B), clear spacing ratio (S/B) and intensity of loading on the right footing with respect to the left footing. Further, variation of the settlement ratio (δ/B) with respect to embedment depth ratio D_f/B is examined. For square and rectangular footings, the interference settlement profile is also investigated by varying the clear spacing ratio (S/B) and the degree of loading. The results were compared to 3D finite element analysis and experimental data that were available.

• Wind and Structures
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• v.21 no.6
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• pp.693-707
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• 2015

The efficiency of wind turbines (WT) is primarily reflected in their ability to generate electricity at any time. Downtimes of WTs due to "conventional" inspections are cost-intensive and undesirable for investors. For this reason, there is a need for structural health monitoring (SHM) systems, to enable service and maintenance on demand and to increase the inspection intervals. In general, monitoring increases the cost effectiveness of WTs. This publication concentrates on the application of two vibration-based SHM algorithms for stability and structural change monitoring of offshore WTs. Only data driven, output-only algorithms based on stochastic subspace identification (SSI) in time domain are considered. The centerpiece of this paper deals with the rough mathematical description of the dynamic behavior of offshore WTs and with the basic presentation of stochastic subspace-based algorithms and their application to these structures. Due to the early stage of the industrial application of SHM on offshore WT on the one side and the required confidentiality to the plant manufacturer and operator on the other side, up to now it is not possible to analyze different isolated structural damages resp. changes in a systematic manner, directly by means of in-situ measurement and to make these "acknowledgements" publicly available. For this reason, the sensitivity of the methods for monitoring purposes are demonstrated through their application on long time measurements from a 1:10 large scale test rig of an offshore WT under different conditions: undamaged, different levels of loosened bolt connections between tower parts, different levels of fouling, scouring and structure inclination. The limitation and further requirements for the approaches and their applicability on real foundations are discussed along the paper.

• Korea journal of population studies
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• v.27 no.1
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• pp.171-201
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• 2004

Modern sciences in the West are deeply rooted in the Greek and Roman cultural heritage. Consequently, the academic achievements accomplished by the scholars of the Arabs including Persian world, the profound thoughts developed in the Indian subcontinent, and the excellent works made by the East Asian scholars have mostly been neglected in the past. This paper attempts to compare the thoughts and theories on population developed by the Western scholars with those of East Asian scolars, in chronological order, ancient, mediaeval, and modern period before Malthus. The thesis that excessive population growth may reduce output per worker, depress levels of living for the masses and engender strife is of great antiquity. In fact, overpopulation in East Asia, especially in China, goes back to very ancient times, most Confucian scholars maintained the notion of a numerical balance between population and environment. They also looked for means to check the increase in numbers. The foundations of a theory of optimum population level, fully developed in the twentieth century, can be found in their writings. Although early population thoughts in China had not advanced far in the analysis of the significance of population size and growth, it had taken only a few steps forward. At some times and to some observers, populousness appeared desirable; at other times and to other observers, it seemed all too evident that the number of people could become too great. These viewpoints foreshowed some of the later developments. The early population literatures reviewed here seem to consist of a number of quite isolated contributions. In fact, however, there may have been a greater continuity of thought than now appears, for many of the contributions may have been lost and there are many gaps in the record. An intensive review on comparing two works, those of Malthus' and Hong, Liang-chi's, are presented in this paper. Only five years before Malthus published his famous work, An Essay on the Principle of Population, Hong published his theories on population. Some of them, Hong insisted, are very similar to the Malthusian concepts of geometrical increase, natural and artificial checks of population. Despite the excellent works in the ancient period, this paper concludes with an investigation of the reasons why modem achievements in scientific areas in the East Asia have been far behind that of the West.

• Journal of the Korean Geographical Society
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• v.31 no.2
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• pp.213-254
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• 1996

The Korean Geographical Society was founded in 1945, when Korea was liberated from the Japanese rule. And The Journal of the Korean Geography activated academic studies of geography by publishing research papers in it. Professor Kang, Dae-Hyun wrote the first two specialized papers of rural geography in 1966: " Flood Plain Settlements on the Han River" and "The Location and Form of the Dispersed Villages around Dae-Cwan-Ryung". The early studies of rural geography were not based on serious academic foundations, such as the adjustment of theoretical notions and a good grasp of subjects. After choosing subjects that came to hand without academic consideration. they simply enumerated generalized items of the results of the field work investigation such as the location the landscape and the process of formation of the settlements. In the 1970s and 1980s, however, rural settlement studies progressed remarkably in Korea. More than 80% of 318 dissertations, theses, or papers collected for this review were written in the late 1980s, and the subjects and methodology became diversified. As may be expected, recent studies are found very systematic and problem-solving in the various fields - contexual understanding spatial structure, the development of clan villages according to the socialization process, the effects of rural-out migration on the change of villages etc. Such a trend can be understood as a reaction to the circumstances under which, as the Western society already experienced, rural villages become washed out by the waves of industralization and urbanization and hardly continue to exist. In this paper, geographical studies of rural settlement which have been carried out in Korea last fifty years will be reviewed under the four headings on the studies related to a) farming villages; b) fishing villages; c) mountain villages: and d) special function villages. Studies of farming villages and related ones are very diverse. The results of the studies carried out last fifty years can be classified into sixteen subjects. Just as, in the West, studies of rural settlement have been mainly concerned with farming villages since rural geography came into being, so, in Korea, they have been centred on farming villages. It is a natural result considering the history of human life. Even in Korea, however the rural settlement is no more an isolated life space which keeps unique traditions of old life style, but it begins to form a dynamic life space connected to big cities by heavy traffic. Because the modern farming villages of Korea have an undetachable connection with the cities, special methodology to solve new problems has been posed in the studies of rural settlement. Many scholars have produced a lot of studies of farming villages, and three of them are prominent: Oh. Hong-Seok, Choi, Ki-Yeop, and Lee, Moon-Jong. Oh, Hong-Seok is a versatile and hard-working scholar who has published more papers than anyone else in the various fields of rural geography such as farming villages, fishing villages, mountain villages, and reclamation villages. And he has expanded his concerns to environment issues in recent years. Choi, Ki-Yeop has maintained that the prototype of Korean rural villages is clan villages continuing to write a series of good papers in which he pursues their regionalizion in the process of socialization. Lee, Moon-Jong divides the spatial organization of side settlement, sahachon (settlement near the temple), religion settlement, orchard settlement, settlement near the foreign military camp, displaced people's settlement. Chung Gam Lok settlement, etc. Though The Korean Geographical Society has half a century's history, academic activties in the field of rural settlement have been performed no more than thirty years. We cannot help saying that it is admirable that in such a rather short time we have five academical schools of the rural geography in Korea. geography in Korea.

• Journal of Korean Academy of Nursing
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• v.21 no.3
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• pp.396-417
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• 1991

In order that nursing care an essential quality of nursing practice be acceptable and satisfying, it is necessary that client's culture be respected and that nursing practice be appropriate to that culture. Since cultural elements are an important influence on health practices and life patterns related to medical treatment, recovery from and prevention of disease, nurses need to have an understanding and knowledge of social and cultural phenomena to aid in the planning of nursing interventions. To understand the health practices surrounding health and illness, the health beliefs and practices of both folk and professional healing systems should be ascertained. Cultural data are required to provide care of high quality to clients and to reduce possible conflict between the client and the nurse. It is nursing's goal to provide clients from various cultures with quality nursing care which is satisfying and valuable. The problem addressed by this study was to identify Korean health practices which would contribute to the planning of professional caring practice with the culture : ultimately this study was intended to make a contribution to the development of the science of nursing. The concrete objectives of this study were ; 1) to identify Korean health practices, 2) to interpret the identitial health practices through traditional cultural thought, and 3) to compare the Korean health practices with those of other cultures. The investigator used the ethnosceintific approach outlined by spradly in a qualitative study. To discover ancestral wisdom and knowledge related to traditional health practeces, the subjects of this study were selected from residents of a small rural mountain village in south west Korea, a place considered to be maintaining and transmitting the traditional culture in a relatively well -preserved state because of being isolated from the modern world. The number of subjects was 18, aged 71 to 89. Research data were collected from January 8 to March 31, 1990. Five categories of health practices were identified : “Manage one's own mind”, “Moderation in all thing”, “Live in accord with nature”, “Live in mutuality with others”, and “Live to the best of one's ability”. Values derived from these ways of thinking from Confucianism, Taoism and Buddhism help fashion a traditional way of life, examplified by the saying “Benifience to all”. Korean thought and philosophy is influenced primerily by Confucianism, Confucian principles of ethics, embedded deeply in the peoples' minds, form the idea that “heaven and human being are intimately united” based on concept that “heaven is, so to speak, reason”. Twoe Gae's theory of existential subjectivity develops the concept of self which is the basis of the spirit of reverence in modern Confucian philosophy. The human md is granted from heaven out of the idea of matter, and what control the mind is the spirit of reverence. Hence the idea of “The primacy of the mind" and provided that one should control one's own mind. The precepts of duty to parents, respect for elders and worship of ancestors, and moderation in all behavior put a restraint on life which directed that one live earnestly according to Nature's laws with their neighbors. Not only Confucianism, but also Buddism and Taoism have had an important effect upon these patterns of ideas. When compared with western culture, Korean health practices tend to be more inclusive, abstract and intuitive while westerner health practices found to be mere concrete, practical and personal. Values and beliefs based and pragmatism and existentialism infuence western civilization, Ethical values may be founded on utilitarianism, which considers what is good for the persons in their circumstances as the basis of conduct and takes a serious view of their practical lives including human aspirations rather than an absolute truth. These philosophical and ethical ideas are foundations for health practices related to active, practical and progressive attitudes. This study should be enable nursing not only to understand clients as reflections of the traditional culture when planning nursing practice, but to dovelop health education corresponding to cultural requiments for the purpose of protection against disease and improvement of health, and thus promote sound health practice. Eventually it is hoped that through these processes quality nursing care as the central idea of the science of nursing will be achieved.