• 한국강구조학회 논문집
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• 제18권2호
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• pp.173-180
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• 2006

구조물의 지진응답은 기초지반조건의 영향을 받는다. 이 연구에서는 고정지반과 연약지반을 고려한 3, 5, 7층 철골 건축구조물의 밑면전단력을 산정하기 위해 선형 시간이력지진해석과 비선형 Pushover 정적지진해석을 수행하였다. 등가정적강성식으로 구한 기초지반강성은 SAP2000의 Link 요소 중 Damper 요소를 사용하여 입력하였다. 범용구조해석 프로그램 SAP2000에 의한 시간이력으로 구한 철골건축구조물의 밑면전단력을 국내내진설계기준, UBC-97 설계응답스펙트럼, Pushover 정적 비선형해석으로 구한 밑면전단력과 비교하였다. 중력하중과 풍하중으로 설계된 철골 건축구조물은 0.11g의 중진에 대해 탄성응답을 보였고, 탄성 연약지반에서 구조물-지반의 상호작용과 지반 증폭에 의해 구조물의 변위와 밑면전단력이 증가되었다. 따라서, 중약진 지역에서의 건축구조물은 연약지반의 특성을 고려하여 탄성지진해석을 수행하는 것이 더 합리적이다.

• 한국지반신소재학회논문집
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• 제4권3호
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• pp.45-52
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• 2005

대부분의 항만구조물은 초연약 지반상에 축조되고 있으며 도로나 건물부지에는 지반개량이 필요하다. 이 논문에서는 여러 사례연구를 통하여 표층처리후의 복토사례에 대하여 몇가지 고려사항을 언급하였다. 또한, 모래나 산토를 이용한 복토공법에 대하여 강도적용이 고려되었다. 국내 복토공법 토목섬유 인장강도는 15t/m, 복토두께는 1.6~3.1m, 점토지반의 표층강도는 $0.2{\sim}1.2t/m^2$이 대표적이다. 표층처리공 시공시 발생되는 지반교란, 점토유출, 장비전도 등의 사고를 최소화하기 위한 연구가 필요하다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.698-705
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• 2004

Application of structural load on soft ground can cause lateral movement as well as ground break due to pressing and shearing of ground. Especially, abutment supported by pile foundation can make pile deformed due to lateral movement of ground in order to have harmful effect on structure. According to the result of this study, it is required to consider disturbance of weak soil layer when using lateral movement countermeasure method by EPS construction method as a result of performing study on safety review and EPS construction method with respect to this based on site where lateral movement occurs due to backside soil filling load at bridge abutment installed on weak ground, and it is required to sufficiently consider soil reduction during design of EPS construction method due to lateral movement deformation of soft clay layer by losing ground horizontal resistance force due to plasticity of ground around pile as well as combination part damage with pile head and expansion foundation.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.412-419
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• 2009

Large quantity of extra soils discharged from excavation site in Songdo area can be treated by hardening agents and utilized in surface stabilized layer overlying thick reclaimed soft soil deposit. Though surface layer stabilization method using cement or lime for very soft soils has been studied in recent years, but studies on moderately soft clayey silt has not been tried. The purpose of this research is to investigate optimum mixing condition for stabilizing Songdo marine soil with low plasiticity. The optimum mixing conditions of hardening agents with Songdo soil such as kind of agents, mixing ratio, initial water content and curing time are investigated by uniaxial compression test and laboratory vane test. The results indicate that strength increases with high mixing ratio and long curing time, while decreases drastically under certain water content before mixing. Finally, optimum mixing condition considering economic efficiency and workability with test results was proposed.

• 한국해양공학회지
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• 제10권4호
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• pp.141-148
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• 1996

Use of stone column for deep ground treatment in soft clay soils is an effective method. The stone column significantly increases load carrying capacity of the soft clay soil. A analysis method for bearing capacity of stone column in soft clay soil is developed. The capacity made by developed method are compared wity observed values from field load test and a reasonable correlation is noted.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.918-927
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• 2008

The problems associated with constructing high-speed concrete track embankments over soft compressible soil has lead to the development and/or extensive use of many of the ground improvement techniques used today. Drains, surcharge loading, and geosynthetic reinforcement, have all been used to solve the settlement and embankment stability issues associated with construction on soft soils. Geosynthetic-reinforced embankment supporting piles method consist of vertical columns that are designed to transfer the load of the embankment through the soft compressible soil layer to a firm foundation and one or more layers of geosynthetic reinforcement placed between the top of the columns and the bottom of the embankment. In the paper, the evaluations of a seismic performance of geosynthetic-reinforced embankment piles for a ultra soft ground during earthquake were studied. the equivalent linear analysis was performed by SHAKE for soft ground. A seismic performance analysis of Piles was performed by GROUP PILE and PLAXIS for geosynthetic-reinforced embankment piles. Guidelines is required for pile displacement during earthquake. Conclusions of the studies come up with a idea for soil stiffness, conditions of pile cap, pile length and span.

• 지질공학
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• 제29권4호
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• pp.427-437
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• 2019

본 연구의 목적은 대단위 연약지반 조성지역에서 도로를 건설할 때 노체층까지 다짐시공 후 압밀처리기 간완료에 따른 여성토를 제거하고 노상층을 시공하므로 공사비용, 시간, 현장관리 등의 문제점을 개선하고자 하였다. 노상층을 연약지반 개량 전에 선시공하여 여성고에 포함시키고 압밀침하 완료 후 선시공된 노상층의 다짐도 유지유무를 현장시험을 통하여 확인하였다. 실험결과, 제 1노상층을 제외한 모든 노상층은 일정하게 유지되었다. 따라서 제 1노상층을 제외하고 시공한다면 도로건설에서 경제적 시공성을 확보하는 것이 유리한 것으로 판단된다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.731-738
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• 2002

Recently, as large constructions on the coast are performed frequently, surface layer stabilization method which Is one of the improvement methods for dredged soft clay has been applied. However, there have been few studies about the surface layer stabilization method. The purpose of this study is to clarify characteristics of ultra-soft marine clay and hardening agent. Also, optimal mixture ratio of hardening agent was verified through the laboratory tests such as statistical analysis and pilot tests. Laboratory tests were performed with proper hardening agent and test soil and standard mixing tables of hardening agent were determined according to ground conditions through statistical analysis. Also, applicability of surface layer stabilization method to field was verified by pilot tests. From the results of the tests, it was found that hardening agent materials such as cement, slag, fly-ash, inorganic salts, arwin, gypsum etc. affect on the appearing compressive strength. It was defined optimal mixture ratio which satisfies the required compressive strength from the statistical analysis. Also, It was compared the effect of ground improvement by cements and hardening agents through the pilot tests. This study will serve as data for design or construction criteria of stabilization of surface layer on ultra-soft marine clay.

• 한국농공학회논문집
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• 제47권6호
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• pp.47-57
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• 2005

Stress distribution in soils is the very important element to design and to solve the problems of settlement, safety of foundations and trafficability of constructing vehicle in civil engineering. This research presents the comparative estimation of the actual and theoretical measurement on the underground stress of outer layer for each soil after the observation of each top soil layer fur its vertical and horizontal stresses in (1) homogeneous sand ground (2) weak stratum with the sand soil (3) weak stratum with gravel of the soil model, and it also investigates the effect of subsidence of ground by the repeated load. The underground stresses fumed out to be different in the value of theoretical and actual measurement after the trial examination of model. This study has the purpose of suggesting the better construction method of running equipment on weak stratum by comparing the estimated value of trial experiment and theory on underground stress of the weak ground surface area and of raising up the necessity of the continuous research hereafter.

• 한국지진공학회논문집
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• 제21권5호
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• pp.255-264
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• 2017

Dynamic numerical simulation of pile-supported slab track system embedded in a soft soil and embankment was performed. 3D model was formulated in a time domain to consider the non-linearity of soil by utilizing FLAC 3D, which is a finite difference method program. Soil non-linearity was simulated by adopting the hysteric damping model and liner elements, which could consider soil-pile interface. The long period seismic loads, Hachinohe type strong motions, were applied for estimating seismic respose of the system, Parametric study was carried out by changing subsoil layer profile, embankment height and seismic loading conditions. The most of horizontal permanent displacement was initiated by slope failure. Increase of the embedded height and thickness of the soft soil layer leads increase of member forces of PHC piles; bending moment, and axial force. Finally, basic guidelines for designing pile-supported slab track system under seismic loading are recommended based on the analysis results.