• 제목/요약/키워드: 성토지반

검색결과 478건 처리시간 0.023초

Excess Pore Water Pressure Response in Soft Clay under Embankment (성토하부 연약지반에서의 과잉간극수압 거동)

  • Kim, Yun-Tae;Kim, Nak-Kyung
    • Journal of the Korean Geotechnical Society
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    • 제18권3호
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    • pp.105-112
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    • 2002
  • Increases in excess pore water pressure without change of surcharge load were reported in clay underneath embankment at Berthierville and Olga sites after the end of construction. These abnormal phenomena could not be explained by classical consolidation theory. This paper presents a nonlinear viscoplastic model to interpret an increase in pore water pressure on natural clay, The proposed model can consider the combined processes of pore water pressure dissipation according to Darcy's law and pore water pressure generation due to viscoplastic strain, as well as time-dependent viscoplastic behaviour and strain rate dependency of preconsolidation pressure. The calculated results using numerical analysis are compared with measured ones under embankments built on soft clay at Berthierville and Olga in Quebec, Canada. It may be possible to explain the phenomenon of excess pore water pressure increase after the end of construction using the proposed nonlinear viscoplastic model.

Estimation of Vertical Stress Developed in Subsurface due to Additional Embankment (추가성토에 의한 성토체 하부에서의 연직응력 산정)

  • Lee, Seung-Hyun;Han, Jin-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • 제12권5호
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    • pp.2410-2415
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    • 2011
  • The needs for enlargement of width of existing embankment have been increasing due to heavy traffic and large amount of transporting goods. In this study, it was intended to derive formula for estimating vertical stress induced by additional embankment. Theoretical background for handling plain strain problem was investigated. It can be seen that stress function considered in the analysis was justifiable for compatibility and boundary condition. Notes for using derived formula were also considered.

Case Study on Embankment Slope Failure by Heavy Rainfall (집중호우에 의한 성토사면 붕괴사례)

  • Park, Jong-Ho;Chang, Buhm-Soo
    • Proceedings of the Korean Geotechical Society Conference
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    • 한국지반공학회 2006년도 추계 학술발표회
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    • pp.626-631
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    • 2006
  • 본 연구는 2006년 7월 집중호우에 의해 많은 인적.물적 피해가 발생한 강원도 지역의 피해 현장을 조사하였으며, 그 중 성토사면붕괴를 붕괴유형별로 구분하고 발생원인과 특성을 분석하여 그에 따른 적절한 대책방안을 제시하였다. 집중호우에 의한 성토사면의 붕괴유형 중 토석류에 의한 도로횡단 배수구조물의 기능상실로 유수가 노면으로 침출되고 수압이 발생하여 도로가 유실된 유형과 하천선형 불량으로 만곡수충부(물이 직접 부딪히는 부분)에서 유속이 빨라져 세굴에 의한 붕괴가 전체성토붕괴사면의 83%를 차지하였다. 이에 대한 대책방안으로는 토석류를 계곡상부에서 부터 예방할 수 있는 방법으로 사방댐 및 그물망 공법 등이 좋은 대책방안이 될 수 있으며, 토석류에 의한 유송잡물을 모두 통과할 수 있도록 충분히 큰 배수시설을 설치하는 방법도 좋은 대책방안이 될 수 있다. 무엇보다 열대성 국지 폭우를 이제 일상의 한반도 기후현상으로 받아들여 주먹구구식의 일회성 대책방안을 지양하고 바뀐 강우특성과 빈도를 고려하여 계획 홍수위를 재산정하고 그에 따라 하천정비계획을 재검토해야 할 것이다.

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Characteristics of Shear Strength and Consolidation Behavior of Soft Ground according to Stage Fill (단계성토에 따른 연약지반의 전단강도 및 압밀거동 특성)

  • Bang, Seongtaek
    • Journal of the Korean GEO-environmental Society
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    • 제21권7호
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    • pp.17-26
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    • 2020
  • The soft ground in the southwest coastal area composed of marine clay is greatly influenced by sediment composition, particle size distribution, particle shape, adsorption ions and pore water characteristics, tide and temperature. In addition, the geotechnical properties are very complex due to stress history, change in pore water, dissolution process and gas formation. In this study, the physical and mechanical properties of the soft ground were evaluated through field tests and laboratory tests to investigate the strength increase characteristics according to consolidation on the soft ground in the southwest coast. In addition, in order to understand the consolidation behavior of soft ground such as subsidence, pore water pressure, horizontal displacement of soil by embankment load, measuring instruments such as pore water pressuremeter, settlement gauge, inclinometer and differential settlement gauge was installed, and a piezocon penetration test was carried out step by step to confirm the increase in shear strength of the ground. Through this, it was confirmed that the shear strength of the ground is increased according to the stages of filling. In addition, by evaluating the properties of consolidation behavior, strength increase and consolidation prediction by empirical methods and theories were compared to analyze the characteristics of strength increase rate and consolidation behavior in consideration of regional characteristics.

Practical Design of the Sandmat Considering Consolidation Settlement Properties (연약지반의 침하특성을 고려한 샌드매트의 실용적 설계를 위한 고찰)

  • Lee, Bongjik;Kwon, Youngcheul;Lee, Jongkyu
    • Journal of the Korean GEO-environmental Society
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    • 제8권5호
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    • pp.31-38
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    • 2007
  • The practical design method on sandmat uses a drain length, rate of consolidation settlement and permeability of sand as a major design factors. And, on the basis of this design process, it has been installed beneath the embankment with same thickness. However, the possibility the underestimation on the thickness of sandmat and the delayed drain have been pointed out by several authors caused by a differential settlement at the center and the end of embankment. In this study, therefore, the effect of the differential settlement on the thickness of sandmat and delayed drain through the numerical analysis of embankment was analyzed. As a result, a substantial sandmat thickness becomes small and the possibility of the delayed drain can be certified because of the development of differential settlement at the center and ends of embankment. As a countermeasure to overcome this problem, the applicability of the mound type sandmat was also investigated by the numerical method. It can be concluded that it maintains the designated substantial sandmat thickness throughout consolidation process, and is useful method to maintain the drain capacity. Especially, the mound type sandmat is effective method for a construction site where can cause a differential settlement such as embankment. Furthermore, it has to be designed on the basis of the accurate prediction of consolidation settlement as well as rate of consolidation settlement, drain length and permeability of sand.

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