• Title/Summary/Keyword: long-term settlement

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크리프와 건조수축을 고려한 철근콘크리트 기둥과 동바리의 축력 재분배 해석법

  • 김선영;이태규;김진근;이수곤
    • Journal of the Korea Concrete Institute
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    • v.13 no.6
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    • pp.629-636
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    • 2001
  • To apply the research results to the design and the construction of the high rise buildings, long-term behavior of reinforced concrete structure have been widely studied. However, shoring and reshoring at early ages have not been considered in the most of studies. The removal of forms and shores has been dealt with one construction sequence. i.e. the deformation occurred at the early age before the removal of shore has been neglected. In this paper, two-dimensional frame analysis program for long-term behavior of reinforced concrete was developed. In the developed program, construction sequence including the settlement and the removal of shores is considered to predict axial force variation due to forms ,shores, and time-dependent concrete stiffness. Analysis results show that the time-dependent axial force of shores is reduced, and the redistributed axial force of the interior column is greater than the value by elastic analysis and that of the exterior column is smaller. In order to demonstrate the validity of this program, the test frame was constructed in sequence of the placement of concrete, form removal, reshoring, shore removal, and the application of additional load. The proposed program predicts experimental results well.

Estimation of Allowable Bearing Capacity and Settlement of Deep Cement Mixing Method for Reinforcing the Greenhouse Foundation on Reclaimed Land (간척지 온실기초 보강을 위한 심층혼합처리공법의 허용지내력 및 침하량 산정)

  • Lee, Haksung;Kang, Bang Hun;Lee, Kwang-seung;Lee, Su Hwan
    • Journal of Bio-Environment Control
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    • v.30 no.4
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    • pp.287-294
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    • 2021
  • In order to expand facility agriculture and reduce greenhouse construction costs in reclaimed land, a greenhouse foundation method that satisfies economic feasibility and structural safety at the same time is required. As an alternative, the allowable bearing capacity and settlement were reviewed when the DCM(Deep cement mixing) method was applied among the soft ground reinforcement methods. To examine the applicability of the greenhouse foundation, the allowable bearing capacity and settlement were calculated by applying the theory of Terzaghi, Meyerhof, Hansen, and Schmertmann. In case of the diameter of 800mm and the width and length of the foundation of 4m, the allowable bearing capacity was 179kN/m2 and the settlement was 7.25mm, which satisfies the required bearing capacity and settlement standards. The calculation results were verified through FEM(Finite element method) analysis using the Mohr-Coulomb material model. The allowable bearing capacity was 169kN/m2 and the settlement was 2.52mm. The bearing capacity showed an error of 5.6% compared to calculated value, and the settlement showed and error of 65.4%. Through theoretical calculations and FEM analysis, it was confirmed that the allowable bearing capacity and settlement satisfies the design criteria as a greenhouse foundation when the width and length of the foundation were 4m. Based on the verified design values, it is expected to be able to present the foundation design criteria for greenhouses through empirical tests such as bearing capacity tests and long-term settlement monitoring.

Development of Real Time Monitoring Program Using Geostatistics and GIS (GIS 및 지구통계학을 이용한 실시간 통합계측관리 프로그램 개발)

  • Han, Byung-Won;Park, Jae-Sung;Lee, Dae-Hyung;Lee, Gye-Choon;Kim, Sung-Wook
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.1046-1053
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    • 2006
  • In the large scale recent reclaiming works performed within the wide spatial boundary, evaluation of long-term consolidation settlement and residual settlement of the whole construction area is sometimes made with the results of the limited ground investigation and measurement. Then the reliability of evaluation has limitations due to the spatial uncertainty. Additionally, in case of large scale deep excavation works such as urban subway construction, there are a lot of hazardous elements to threaten the safety of underground pipes or adjacent structures. Therefore it is necessary to introduce a damage prediction system of adjacent structures and others. For the more accurate analysis of monitoring information in the wide spatial boundary works and large scale urban deep excavations, it is necessary to perform statistical and spatial analysis considering the geographical spatial effect of ground and monitoring information in stead of using diagrammatization method based on a time-series data expression that is traditionally used. And also it is necessary that enormous ground information and measurement data, digital maps are accumulated in a database, and they are controlled in a integrating system. On the abovementioned point of view, we developed Geomonitor 2.0, an Internet based real time monitoring program with a new concept by adding GIS and geo-statistical analysis method to the existing real time integrated measurement system that is already developed and under useful use. The new program enables the spatial analysis and database of monitoring data and ground information, and helps the construction- related persons make a quick and accurate decision for the economical and safe construction.

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Analysis of Ground Subsidence according to Tunnel Passage in Geological Vulnerable Zone (지질취약구간 터널통과에 따른 지반침하량 분석)

  • Choi, Jung-Youl;Yang, Gyu-Nam;Kim, Tae-Jun;Chung, Jee Seung
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.3
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    • pp.393-399
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    • 2020
  • In this study, the subsidence behavior caused by groundwater ex-flow in a limestone cavity encountered during tunnel excavation was quantified based on numerical analysis and the effect was analyzed. Based on the groundwater level and surface subsidence surveyed at the site, a numerical analysis technique was applied to analyze the characteristics of the subsidence behavior according to the tunnel passage of the geological vulnerabilities. The results of groundwater seepage-coupled analysis were analyzed to reflect the actual ground subsidence behavior. As a result of the study, it was analyzed that the ground subsidence due to the tunnel excavation in the limestone common section(the geological vulnerable zone) was analyzed that the dramatical decrease in groundwater level was the main cause. As a result of numerical analysis, it was analyzed that the long-term cumulative settlement of the asphalt surface after the groundwater ex-flow was 76~118mm due to the reduction of the volume of the soil layer due to the decrease in the groundwater level, and the settlement amount increased as the depth of the soil layer increased.

Seismic Behavior of Deterioration Reservoir Embankment Using Dynamic Centrifugal Model Tests (동적원심모형실험에 의한 재개발 저수지의 동적 거동특성)

  • Park, Sung-Yong;Chang, Suk-Hyun;Lim, Hyun-Taek;Kim, Jung-Meyon;Kim, Yong-Seong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.58 no.3
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    • pp.91-100
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    • 2016
  • Recently, lots of damages have been lost because large magnitude earthquakes were occurred in the world. It has been increased the number of earthquakes in Korea. It needs improvement required for the repair of deteriorated reservoirs, reinforcement and raised reservoir coping with climate change and earthquake. This study aims to investigate the seismic behavior of deterioration reservoir levee using dynamic centrifugal model test. Therefore, two case tests in centrifugal field of 60 g, the result has provided the influence on the acceleration response, displacement, settlement and the pore water pressure of the reservoir with earthquakes. From the results larger displacement and acceleration response at the front side of reservoir embankment with poor-fabricated core in seismic condition may degrade overall stability. Reasonable reinforcement method of the raised reservoir embankment is required for ensuring long-term stability on earthquake.

The Time-Dependent Behavior Characteristic of Bottom Ash by Maximum Particle Size and Application of Creep Models (Bottom Ash의 최대입경에 따른 시간-의존적 거동 특성 및 크리프 모델 적용성 검토)

  • Kim, Tae-Wan;Son, Young-Hwan;Bong, Tae-Ho;Noh, Soo-Kack;Park, Jae-Sung
    • Journal of The Korean Society of Agricultural Engineers
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    • v.55 no.5
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    • pp.9-16
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    • 2013
  • This study finds the characteristics of long-term settlement of Bottom Ash and to review the application of Singh-Mitchell creep equation and Burgers Model to the creep behavior of Bottom Ash. In the undrained state, it was confirmed that creep behavior appeared in the range to 30-80 % of the maximum deviator stress by applying condition in other three stresses through triaxial compression test after isotropically consolidation. By using sieve analysis, it was compared to each sample that was passed through 9.5 mm, 2 mm, 0.25 mm sieves. Also, using Singh-Mitchell creep equation and Burgers Model, it was compared between the theoretical behavior and the observed behavior for each sample. In the result, it is found that creep behavior of Bottom Ash is similar to the theoretical behavior of Singh-Mitchell creep equation and Burgers Model in early stage and it is possible to predict creep behavior of Bottom Ash by these models.

Capacity Evaluation of Cylindrical Plastic Board Drain with The Composite Discharge Capacity Apparatus (복합통수능시험기를 이용한 실린더형 플라스틱 보드 드레인의 성능 평가)

  • Lee, Chan-Woo;Jung, Du-Hwoe;Kim, Yun-Tae;Jin, Kyu-Nam
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.293-299
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    • 2008
  • If a conventional type of Plastic Board Drain (PBD) is installed to the deep clay deposit, it is subjected to a high lateral earth pressure. a flow channel of PBD may be reduced by the collapse of cores and clogged by the intrusion of filter into the space between cores which are made by lateral pressure. It could decrease the ability of initial discharge capacity and the reliability of long term discharge capacity. A cylindrical plastic board drain (C-PBD) considered in this study consists of cylindrical core and several supports so that it can prevent the reduction of area of flow channel from the higher lateral earth pressure effectively. The discharge capacity of C-PBD was compared to that of a conventional PBD through performing experiments using the composite discharge capacity apparatus which can consider in-situ condition such as penetration of drains, ground settlement and discharge capacity. As a result, C-PBD showed much better performance than PBD in the ability of discharge. It was observed that the C-PBD was folded whereas the conventional PBD was folded after the experiment.

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A Study on Inhabitant's Mental and Residential Environment Improvement of Old Residential Area in Pohang (포항시 노후 주거지의 거주자 의식과 주거환경정비방향)

  • Kwon, Yong-Il;Han, Sang-Hoon
    • Journal of the Korean housing association
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    • v.22 no.1
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    • pp.75-84
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    • 2011
  • This study examines the characteristics and the degree of inhabitant's mental against to their residential environment which was developed within the boundary of Haedo Dong in Pohang City during the 1970s and the early of 1980s and currently designated as programed site for Urban Maintenance Project. Findings from the study are as follows; First, the numbers of household occupied by lessee were greater than the numbers of household occupied by homeowner. Second, most of the lessee was living in single family household. Third, although the degree of satisfaction for their residential environment was not so good in general perspectives the degree of satisfaction of the long term residents for their residential environment was slightly higher than the others. Fourth, the degree of satisfaction for their neighborhood was the most while the degree of satisfaction for public facilities such as parks was the least. Fifth, Urban maintenance project shall be proceeded to raise re-settlement ratio of residents, to enforce a business by steps, to lead positively participation of a resident and to enlarge role of administration.

A Study on the Appropriate Allotment Methodology of Middle School District According to Urban Growth - Focusing on the Middle School District in Sejong City - (도시성장에 따른 효율적인 중학교군 설정 방법 연구 - 세종특별자치시의 중학교군을 중심으로 -)

  • Cho, Chang-Hee;Lee, Hwa-Ryong;Dong, Jae-Uk
    • Journal of the Korean Institute of Educational Facilities
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    • v.23 no.5
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    • pp.11-18
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    • 2016
  • This study aims at proposing the efficient settlement of middle school district and the appropriate allotment of middle school student. It focuses on the middle school district in Sejong city where has recently been developed. Firstly this study analyzes the long-term plans of school establishment, the current state of the student accommodation and the number of increasing students according to the continuing developments. To set up the efficient school district, it investigates the number of students per school district, school location and the commuting condition to each school. Throughout a question investigation to school parents, it analyzes the school choice factors - distant to school, school environment, school facilities, teacher's passion, the school curriculum, and so on. Furthermore it carries out focus group interview(FGI) targeting parents and teachers. It proposes a short-distance allotment method as an appropriate disposition of middle school student in Sejong city, which conducts a process of the first-application and the later-draw with a community as a unit.

A Exploratory Study of Integration-Support Paradigm for Transnational Marriage and Family: Focused on the Dongdaemun-gu Transnational Marriage and Family Support Center (결혼이민자가족을 위한 통합지원 패러다임 모색에 대한 탐색적 연구 -동대문구 결혼이민자가족지원센터를 중심으로-)

  • Oh, Yoon-Ja
    • Journal of Family Resource Management and Policy Review
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    • v.11 no.4
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    • pp.73-92
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    • 2007
  • This study explored the integration-support paradigm for transnational marriages and families as a well-grounded service model supporting a transnational family of immigrants in Korea at a time when Korean society showed increased interest in interracial marriages. The research mainly focused on the Dongdaemun-gu Transnational Marriage and Family Support Center, utilizing the relative actual practice at the center and the secondary data of previous studies. The findings were as follows: The integration-support paradigm for transnational marriage and family comprised of the following elements : the institutionalization of welfare and medical services; the systematization of legal institution and execution the settlement of mid- and long-term policies and the practical programs of the government proper approaches to the formation of a healthy marital couple and family relations; total services related to rearing and educating children properly including education cost support to family incomehousing for the stabilization of family life support for socio-cultural exchanges within the family : as well as the radical conversion of social recognition of a transnational family. This paradigm is expected to be a well-grounded service for the integration-support of transnational families.

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