• Title/Summary/Keyword: Intermediate Foundations

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Dynamic response of pile foundations with flexible slabs

  • Kaynia, Amir M.
    • Earthquakes and Structures
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    • v.3 no.3_4
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    • pp.495-506
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    • 2012
  • An elasto-dynamic model for pile-soil-pile interaction together with a simple plate model is used in this study to assess the effect of flexible foundation slabs on the dynamic response of pile groups. To this end, different pile configurations with various slab thicknessesare considered in two soil media with low and high elastic moduli. The analyses include dynamic impedances and seismic responses of pile-group foundations. The presented results indicate that the stiffness and damping of pile foundations increase with thickness of the foundation slab; however, the results approach those for rigid slab as the slab thickness approaches twice the pile diameter for the cases considered in this study. The results also reveal that pile foundations with flexible slabs may amplify the earthquake motions by as much as 10 percent in the low to intermediate frequency ranges.

Development of Design and Field Quality Control Techniques of Shallow Foundation Resting on Intermediate Geomaterials (중간토에 지지된 직접기초의 설계 및 현장품질관리기법 개발)

  • Byun, Young-Gi;Park, Young-Ho;Jeong, Hoon-Jun;Lee, Woo-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.1148-1155
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    • 2010
  • To suggest a modified shallow foundation design method which can be considered the scale effect of foundation on IGM(intermediate geomaterial) soil layer, the weathered soil layer that is uniformly formed up to 8m(2B) with over 50 N-value is selected and 3 times field loading tests are performed on several sized square-shaped shallow foundations with 30, 75, 150, 240 and 400cm in width respectively. Because the soil modulus of elasticity(Es) calculated by soil investigation and 1st field test(PBT) results showed an underestimated tendency, a modified correlation is required for the reasonable estimation of Es on the weathered soil. Also, the N-value was increased with an increasing in depth. However, the N-values around the test foundations showed the different values even though the foundations on the same level because the test site was arranged by excavation. Therefore, the more detail soil investigations are required for the each test foundations respectively. Since Es based on elasticity theory is determined by the stress distribution shape of the foundation and elasticity modulus of the soil, the scale effect considered pressure-settlement curve can be clearly derived from the correlation on stress distribution shape and the variation of soil elasticity modulus with depth. Therefore, the modified correlation will be suggested to estimate a reasonable Es on the weathered soil, and the scale effect considered shallow foundation design method is also developed based on the elastic theory and field tests in this research.

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A Study on the Bearing Capacity of Rammed Aggregate Pier as the Intermediate Foundations (중간기초개념으로서 짧은 쇄석다짐말뚝의 지지력 특성에 관한 연구)

  • CHUN BYUNG-SIK;KIM KYUNG-MIN;KIM JUN-HO
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.11a
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    • pp.247-252
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    • 2004
  • To secure stability and availability of Rammed Aggregate Pier method as the foundation of a structure, the bearing capacity and failure behavior characteristics was studied through soil laboratory tests in a model ground. In this study, soil laboratory tests use carried out to find the applicability of RAP method as the foundation of a structure. And bearing capacity and the failure mechanism of RAP method was studied according to relative density($60\%,\;70\%,\;90\%$), diameter(45mm, 60mm, 70mm) of each pier ana depth(5cm, l0cm, 15cm, 20cm, 25cm, 30cm). Earth pressure cell is set up approach RAP and 1.0D space at RAP center. Bearing acpacity and the failure mechanism of RAP is investigated by load test As a result, bulging failure was happened in $5\~10cm\;(1.0D\~2.00)$ depth which the maximum lateral earth pressure is acting. Especially, diameter changing of RAP are in inverse proportion to the relative density and the lateral stress is very much influenced by the lateral earth pressure in every layer and tends to decrease according to depth.

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What are the Community Foundation Doing, and What Difficulties do They Have? (지역재단의 운영실태와 문제점)

  • Noh, Hyejin;Lee, Hyunok
    • The Journal of the Korea Contents Association
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    • v.17 no.8
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    • pp.226-240
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    • 2017
  • The purpose of this study is to explore in depth what is the identity of the community foundation, how it operates, and what difficulties it faces. For this purpose, this study conducted in-depth interviews with 5 practitioners working in community foundations. The results of the study are as follows. First, it is important for the participants to identify what their organizations are doing for the community rather than to distinguish them by their legal status. Second, community foundations recognize fundraising as an important achievement regardless of the type. Third, community foundations have experienced difficulties in raising funds, establishing community foundation identity, relationship with other nonprofit organizations in the area, citizen participation, organizational capacity and institutional instability. Therefore, as a policy alternative for community foundations, this study suggested that the establishment of identity and model of community foundation suited to Korean situation, the enhancement of capacity as intermediate support organizations, and the administrative and institutional support of government.

A Study on the Point Makeup Purchasing and Using Behavior according to the Personal Color Awareness (퍼스널 컬러 인식에 따른 색조 화장품 구입 및 사용행동)

  • Woo, Soo-Jin;Kim, Yong-Sook
    • The Research Journal of the Costume Culture
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    • v.19 no.5
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    • pp.889-902
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    • 2011
  • The purposes of this study were to identify point makeup purchasing and using behavior according to the personal color awareness. Most women considered their favorite color first when purchasing lipsticks and skin color when purchasing cheek powder or foundation. They considered makeup concept first when applying lipsticks, eye shadows, and cheek powder but skin color applying foundations and manicures. Factors of personal color awareness were preferences & utilization awareness, other's advice, and direct awareness, and were segmented into PC intermediate group, high PC group, and PC retard group. PC intermediate group were in the late 20's and the early 30's, average incomes with high education, and patronized discount stores for point makeups, used fashion color as a criterion when selecting lipsticks, foundations, and manicures, apparel color when applying eye shadows, skin color when applying cheek creams, and preferred imported lipsticks and manicures. High PC group were among unmarried women in the early 20's, university students, high income households with medium level of pocket money, spent more for point makeup, and patronized department stores and internet shopping mall, used skin color or fashion color as criteria when selecting point makeup, referenced makeup concept when applying point makeup, preferred imported point makeup. PC retard group were among married women in the late 30's with low education and low income, spent less for point makeup and pocket money, and selected domestic point makeup, used their favorite color as a criterion when selecting point makeups and apparel color when applying lipsticks and cheek creams.

The Effect of Information Technology on Arms-Length Buyer-Supplier Relationship

  • Kim, Soo-W.
    • International Journal of Quality Innovation
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    • v.9 no.3
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    • pp.57-69
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    • 2008
  • This paper posits that arm's length buyer-supplier relationship as the intermediate type between market exchange relations and strategic partnership might be advisable, and information technology may have a role as a mechanism actualizing the effects of such arm's length relationship by strategic supply-line diversification. Based on the theoretical analysis on interactive feedback relationships among IT level, buyer-supplier relationships, and supply chain structure, we suggest a set of advisable buyer-supplier relationship type for efficient supply chain management. Also, doing so would be helpful in suggesting a dynamic IT investment and adoption model appropriate for the establishment of productive buyer-supplier relationship, and further in providing theoretical foundations and practical guidelines on the role and function of B-to-B E-commerce for efficient SC integration.

Feasibility Exploration of Social Cooperatives as a Community Social Work Practice Model (지역사회복지실천모델로서 사회적협동조합의 가능성 탐색)

  • Cho, Mihyoung
    • Journal of Agricultural Extension & Community Development
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    • v.21 no.3
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    • pp.91-119
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    • 2014
  • This study explored feasibility of social cooperatives as a strategy of struggle to social exclusion in the social services area based on the relationships between people. Is social cooperatives on the Fundamental Act on Cooperatives a new type of social welfare service providers comparing the social welfare foundations and social enterprises? Would be expected as social inclusion processes effects arising from the properties of cooperative in social welfare sector? If social welfare institutions function as an intermediate medium between government and users, social cooperatives can be performed function in the community in a variety of cooperative relationships with Multiple stakeholders, e.g. various service providers, care-givers, social workers, and users, etc., conflicting the interests. In this perspective, looked the possibility of social cooperatives as community welfare practice model.

Study of Dynamic Characteristics of West Coast Saemangeum Sand by Torsional Shear Test (비틂전단시험에 의한 서해안 새만금 모래의 동적특성 연구)

  • Jeon, Hong-Woo;Son, Su-Won;Kim, Jin Man
    • Journal of Ocean Engineering and Technology
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    • v.27 no.6
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    • pp.73-80
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    • 2013
  • The dynamic characteristics of west coast sand were investigated in order to evaluate the design properties of the offshore wind turbine foundations to be constructed in the West Sea. Torsional shear tests were performed at different confining pressures and densities on specimens constituted by the dry fluviation method. The strain-dependent shear modulus and damping curves were obtained, together with modulus degradation curves. The results show that the confining pressure is more influential on the dynamic characteristics of the sand than the density. It was also found that the dynamic curves from this study were similar to those proposed by others. The modulus degradation ratio $G/G_{1st}$ varies slightly at a small strain level, but increases significantly once beyond the intermediate strain level.

A Study on Preschool Children's Perceptions of a Robot's Theory of Mind (유아에게 인지된 로봇의 마음이론에 관한 연구)

  • Lee, Hawon;Shin, Wonae;Cho, Hyekyung
    • The Journal of Korea Robotics Society
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    • v.15 no.4
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    • pp.365-374
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    • 2020
  • In this paper, we analyzed how 5-year-old children perceive a robot's ability to attribute mental states to oneself and to others, which shall hereafter be referred to as a robot's theory of mind (RToM). A total of 34 5-year-old children were given two typical false-belief tasks, an 'unexpected-contents task' and a 'change-of-location task', in order to evaluate whether a child's perceived RToM was connected to their own ToM. In addition, we investigated whether a child's perception of RToM was influenced by either a priori experience with robots or that child's gender. The results are as follows. Firstly, the 5- year-old preschool children universally recognized robots as beings that have a human-like mind both in 1st order and 2nd order perspectives, which indicates that children perceive robots as beings distinct from mechanical toys. Secondly, a priori child-robot interaction experience was found to have a positive influence on a child's perceived RToM. Thirdly, the gender of children did not significantly affect their perceived RToM. This study serves to add to the macroscopic results of prior research, which indicate that children perceive robots as intermediate beings between living and inanimate objects: significantly, it analyzes the children's perception of robots through the lens of theory of mind, which is one of the key elements of cognitive development. This research lays the foundations for designing effective child-robot interactions, in situations in which robots serve as peers or assistants for educational purposes.

Reduction Factor for the Site Coefficient of a Building built on a Poor-backfilled Embedded Foundation (뒷채움이 부실한 묻힌기초 위에 세워진 건축물의 지반증폭계수에 대한 저감계수)

  • Kim, Yong-Seok
    • Journal of the Earthquake Engineering Society of Korea
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    • v.16 no.1
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    • pp.1-12
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    • 2012
  • In this paper, the reduction factors to calculate the site coefficients of an embedded foundation are estimated, considering the effect of a poor backfill for the seismic design of a building built on an embedded foundation. This is determined by utilizing in-house finite element software, P3DASS, which has the capability of horizontal pseudo 3D seismic analysis with nonlinear soil. The 30m thick soil on stiff rock was assumed to be homogeneous, elastic, viscous and isotropic, and equivalent circular rigid foundations with radii of 10-70m were assumed to be embedded 0, 10, 20, and 30 m in the soil. Seismic analyses were performed with 7 bedrock earthquake records de-convoluted from the outcrop records; the scaling of the peak ground accelerations were to 0.1 g. The study results show that the site coefficients of a poor-backfilled foundation are gradually reduced as the foundation embedment ratio increases, except in the case of a small foundation embedded deeply in the weak soft soil. In addition, it was found that the deviation of the site coefficients due to the foundation size was not significant. Therefore, the typical reduction factors of an embedded foundation with poor backfill are proposed in terms of the shear wave velocity and site class. This is in order to find the site coefficients of an embedded foundation by multiplying the reduction factor by a site coefficient of a surface foundation specified in the design code. They can then be interpolated to determine the intermediate shear wave velocity.