• Journal of the Korean Geotechnical Society
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• v.18 no.5
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• pp.55-65
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• 2002

Model tests were performed to investigate the mechanism of lateral earth pressure on a buried pipe, which was installed in a plastic flowing soil mass undergoing lateral movement. On the basis of failure mode tests, the equation of lateral earth pressure to apply Maxwell's visco-elastic model was proposed to consider the soil deformation velocity. Through a series of model tests of differential soil deformation velocity, lateral earth pressure of theoretical equation was compared with experimental results. When lateral soil movement was raised, the lateral earth pressure acting on buried pipe increases linearly with the soil deformation velocity. It shows that the lateral earth pressure on buried pipe is largely affected by soil deformation velocity. When plastic soil movement was raised, lateral earth pressure predicted by theoretical equation showed good agreement with experimental results. Also, coefficient of viscosity by theoretical equation had a good agreement with direct shear test results.

• Journal of the Korean Geotechnical Society
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• v.28 no.12
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• pp.99-110
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• 2012

Inclined Earth Retaining Structure Method (IER method, briefly) is developed in order to improve the existing earth retaining method. In IER method, there are three main structures, front support, back support, and head binding. Especially, back support acts the role that reduces the earth pressure acting on the front support. In this study, the stability according to the installation angle and stiffness of front or back support is analysed by model tests. By the test results, it is known that inclined back support is very effective to reduce the earth pressure acting on the front support. Especially, the effect of the stiffness and installation angle of back support is analysed.

• Journal of the Korean Geotechnical Society
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• v.22 no.2
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• pp.29-39
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• 2006

In the companion paper (Paik 2006), a new formulation for calculating the nonlinearly distributed active earth pressure acting on a caisson backfilled with crushed rock and sand is proposed, and it takes into account arching effects as well as difference in internal friction angles and unit weights between sand and crushed rock. In this study, in order to partially check the accuracy of the proposed equation, the results of the proposed equation are compared with the equation proposed by Paik (2003a) for caissons with rough surface and homogeneous backfill, and are compared with results of Rankine's theory for caissons with smooth surface and homogeneous backfill. In addition, a parametric study is performed to investigate the effect of $phi_{r}$, $phi_{s}$, $\delta_{r}$, $\gamma_{r}$, $\gamma_{s}$ and $\beta$ on the magnitude of active earth pressure acting on the caisson, and construction methods for minimizing active earth pressure on the caisson are also provided based on the results of a parametric study.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.10a
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• pp.213-214
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• 2000

총 암모니아성 질소(TAN)은 고밀도 양식에서 한계요소로 작용하는 수질인자 중의 하나이다. 생물학적 처리법에 의한 암모니아의 제거는 순환여과식 양식 시스템의 설계에서 가장 중요한 부분이다. 효율적인 순환 여과식 양식 시스템을 위해서는 생물반응기의 질산화 속도식을 구하여 적정한 용량의 처리시스템을 설계하여야 한다. (중략)

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2003.08a
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• pp.98-102
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• 2003

지금까지 실무에서는 경사식 방파제 적정 단면 결정시 피복재 산정 및 설계파에 대한 파력을 산정하여 상치콘크리트 구조물의 안정성을 검토하는 것이 전부였다 하지만 현장에서 발생하는 상황은 더 많은 변수들이 작용하는 것을 보여 주고 있다. 예를 들면 파에 의하여 발생하는 투과파 및 월파로 제체의 내부 및 배면 석재의 이탈이 발생하는 경우는 익히 보아 왔던 일이지만, 반대로 월파가 발생하지 않았는데도 불구하고 제체의 침하와 배면의 석재에 이탈 즉 세굴이 발생하는 경우도 있다. (중략)

• Monthly Duck's Village
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• s.132
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• pp.28-33
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• 2014

오리고기 소비의 계절인 여름이 찾아왔다. 다양한 효능을 갖고 있는 오리는 사계절 내내 먹기에 손색이 없지만 여름에는 특히 원기회복식과 보양식 수요가 많은 계절이기 때문에 3대 보양식 중 하나로 꼽히는 오리를 찾는 사람들이 많다. 조선 명의 허준이 지은 동의보감에는 '오리고기가 오장육부를 모두 편하게 하는 몇 안 되는 음식 중에 하나'라고 기록되어 있으며, 중국 명나라 의서인 본초강목에도 '오리는 해독작용을 하고 혈액순환을 돕는다'고 적혀 있다. 과거 오래전부터 입증된 오리의 효능은 현재까지도 의사, 교수, 요리연구가 등 전문가들에 의해 여러 차례 소개되고 있다. 전문가들이 말하는 오리예찬 내용을 살펴보고, 무더위를 대비한 체력보강 차원에서 오리고기를 든든히 섭취할 것을 제안해본다.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.324-325
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• 2001

총 암모니아성 질소(TAN)은고밀도 양식에서 한계요소로 작용하는 수질인자 중의 하나이다. 생물학적 암모니아 처리공정의 효율적인 설계를 위해서는 생물반응기의 암모니아 제거속도식을 구하여 처리시스템의 최적 용량을 구하여야 한다. 그러나 현재까지 진행된 고정화 미생물을 이용한 암모니아 제거공정에 대한 연구는 고정화 재질의 특성이나 장치의 운전효율에 대한 것으로 속도식에 대한 연구는 부족하다. (중략)

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.4
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• pp.469-480
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• 2022

To design the crown wall of rubble-mound breakwaters, the horizontal wave load should be available, but determining this load remains difficult. Lee et al. proposed modification factors for Goda's formula for the horizontal wave pressures on acrown wall. The empirical formula by Lee et al. was based on a two-dimensional model test with a relatively narrow armour crest width in front of the crown wall. In this study, a series of experiments at the same facility were conducted on the horizontal wave pressures on the crown wall of a rubble-mound breakwater with a wide armour crest width. As a result, the pressures of the unprotected part of the crown wall were nearly identical to the narrow crest width. However, the pressures of the protected part tended to decrease with a change in the armour crest width. From the experimental results, the horizontal pressure modification factors of Goda's formula including the armour crest width effect are suggested here and are likely applicable to practical designs of the crown walls of rubble-mound breakwaters covered with tetrapods.

• The Korean Journal of Petroleum Geology
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• v.1 no.1 s.1
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• pp.1-13
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• 1993

The diagenetic history of the carbonate rocks of the Mungok Formation near Machari area, Kangwondo, was investigated based on textural, isotopic, and chemical data. Paragenetic relationship among diagenetic minerals, coupled with their distinct geochemical contents, shows that the Mungok Formation have undergone several stages of diagenetic events: 1) shallow marine, 2) meteoric, 3) shallow to intermediate burial, and 4) deep burial diagenesis. Shallow marine diagenesis includes fibrous calcite cementation, micritization, and framboidal pyritization, and meteoric diagenesis involved dissolution and recrystallization of unstable allochems (both aragonite and HMC), syntaxial overgrowth on echinoderm fragments, and equant calcite cementation. During shallow to intermediate burial, idiotopic dolomite and chert formed, and xenotopic dolomitization took place before stylolitization of the rocks. After the rocks were deeply buried, saddle dolomitization, second stage of silicification, and dedolomitization occurred.

• Journal of the Korean Geotechnical Society
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• v.22 no.6
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• pp.27-40
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• 2006

Damage of cut-and-cover tunnel lining can be attributed to physical and mechanical factors. Physical factors include material property, reinforcement corrosion, etc. while mechanical factors include underground water pressure, vehicle loads, etc. This study is limited to the modeling of rigid circular cut and cover tunnel constructed at a depth of $1.0{\sim}1.5D$ in loose sandy ground and subjected to a vibration frequency of 100 Hz. In this study, only damages due to mechanical factors in the form of additional loads were considered. Among the different types of additional, excessive earth pressure acting on the cut-and-cover tunnel lining is considered as one of the major factors that induce deformation and damage of tunnels after the construction is completed. Excessive earth pressure may be attributed to insufficient compaction, consolidation due to self-weight of backfill soil, precipitation and vibration caused by traffic. Laboratory tunnel model tests were performed in order to determine the earth pressure acting on the tunnel lining and to investigate the applicability of existing earth pressure formulas. Based on the difference in the monitored and computed earth pressure, a factor of safety was recommended. Soil deformation mechanism around the tunnel was also presented using the picture analysis method.