• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 연약지반처리위원회 학술세미나
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• pp.14-22
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• 1999

Daylight collapse have been occurred by about 6.$^{0}$ m deep at ground surface which connected to the ground surface and excessive overbreak have been occurred by the space and height of 3.$^1$~6.$^2$m at crown head part of the tunnel during tunnelling of lower-half part after completing upper-half part on tunnelling of a phyllite mountain by NATM method at the construction work of two way-double track national road. This study is a successful illustration case of earth improvement by confirming structural safety of the tunnel in a whole through solving the cause of the tunnel collapse and the work have completed successfully through applying such earth strengthening method as cement mortarㆍcement milk injection, S.G.R, steel pipe reinforced multi-step grouting etc.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 지반공학 공동 학술발표회
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• pp.581-590
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• 2005

The grouting method is widely used as the impermeable effect and ground reinforcement in construction. But, it has a problem that cement and grout material are not mixed well in the injection tip equipment and an opposite flow and interception state of the chemical grouting is happened. so, continuous work is difficult. McG method installed a special grouting and device, made possible go well mixing of grouting material and prevent flowing backward and block of nozzle also diversify powder rate of cement that is grouting material to select sutible material in layer conditions. YSS that lowered $Na_2O$ influencing durability and circumstance is developed by gel-forming reaction material. so eco-circumstance and durability is increased by minimizing dissolution of underground water. In this study, it is assumed that seepage state of the injection material using a special injection tip equipment and a unconfined compressive strenth by mixing a various injection material of various. And it is confirmed that strenth increase effect and permeable decrease of the improved body through the test execution and field execution.

• 한국터널지하공간학회 논문집
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• 제11권2호
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• pp.199-211
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• 2009

쾌적한 지상공간의 삶을 위하여 전세계적으로 지하공간 개발이 활발히 이루어지고 있으며, 그 규모도 점차 대형화하고 었는 추세이다. 하지만 밀집한 상부 구조물에 대한 피해 우려와 기존 지하공간과의 간섭 등으로 인하여 새로운 지하공간 건설 시 많은 주의가 필요한 실정이다. 천층에 굴착되는 터널의 경우, 굴착으로 인한 상부 구조물의 피해를 최소화하기 위하여 구조물 하부 및 터널 주변지반의 보강이 필수적이나 그 적정범위에 대한 기준은 마련되어있지 않은 설정이다. 본 논문에서는 직경 20 m의 대단면 터널이 구조물 하부에 시공되는 경우에 대해서 수치해석을 실시하여, 터널과 구조물간의 수직 및 수평이격거리에 따른 구조물 피해정도를 조사하였고 보강이 필요한 경우에는 각각의 경우별로 최적의 보강범위를 제시하였다. 본 논문에서 다룬 지반조건에 대한 해석결과, 수직이격거리가 0.50(D 터널등가직경)인 경우에는 수평이격거리가 0D에 근접하면서부터 보강이 필요한 것으로 나타났으며, 수직이격거리가 0.75D인 경우에는 터널이 구조물 하부에 위치할 때 보강이 필요하였다. 또한 수직이격거리가 1D 이상인 경우에는 수평이격거리에 상관없이 보강이 필요 없는 것으로 나타났다. 구조물 기초지반 보강범위는 갚이 7 m, 폭은 구조물 전제를 포함하여 터널 측벽에서 5 m 벗어난 곳까지이다. 상황에 따라 적절한 보강공법을 선택하였을 경우, 이와 같은 보강범위는 구조물 안정에 충분한 것으로 나타났다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 가을 학술발표회 논문집
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• pp.127-134
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• 2000

Soil nailing is in-situ ground improvement technique of reinforcing soils using passive inclusions for the purpose of slope stability. Also soil nailing, in general, was used and studied as a reinforcement technique at cut slope, but this paper presents the results of study for soil nailing application as a reinforcement technique at the banking over slided slope. In-situ pull-out tests of nails, instrumented with strain gauges, were performed to investigate the maximum pull-out load and to calculate the unit side resistance in each different layer. And the apparent average unit side resistance of this study was compared with that of other sites installed at cut slope.

• Geomechanics and Engineering
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• 제35권5호
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• pp.555-570
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• 2023

In the current study, a series of experimental and analytical evaluations were performed to introduce the horizontal pseudo static coefficient (kh) as a function of the wall configuration and the reinforcement type for analyzing reinforced soil walls. For this purpose, eight shaking table tests were performed on reduced-scale models of integrated and two-tiered walls reinforced by metal strip and geogrid to determine the distribution of dynamic lateral pressure in the walls. Then, the physical models were analyzed using Mononobe-Okabe method to estimate the value of kh required to establish the dynamic lateral pressures similar to those observed in shaking table tests. Based on the results, the horizontal pseudo static coefficient and the position of resultant lateral force (R) were introduced as a function of the horizontal peak ground acceleration (HPGA), the wall configuration, the reinforcement type as well as maximum wall displacement.

• ETRI Journal
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• 제45권5호
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• pp.735-745
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• 2023

This paper surveys recent multiagent reinforcement learning and neural Myerson auction deep learning efforts to improve mobility control and resource management in autonomous ground and aerial vehicles. The multiagent reinforcement learning communication network (CommNet) was introduced to enable multiple agents to perform actions in a distributed manner to achieve shared goals by training all agents' states and actions in a single neural network. Additionally, the Myerson auction method guarantees trustworthiness among multiple agents to optimize rewards in highly dynamic systems. Our findings suggest that the integration of MARL CommNet and Myerson techniques is very much needed for improved efficiency and trustworthiness.

• Geomechanics and Engineering
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• 제28권1호
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• pp.1-10
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• 2022

In Korea, accidents related to the collapse of deteriorated aging reservoirs occur every year. The grouting method is generally applied to reinforce an aging reservoir. However, when using this method, different reinforcing effects appear depending on the ground conditions. Thus, new construction methods and materials capable of providing consistent reinforcing effects are required. In this study, the direct shear test (DST), model test, and simulation analysis were performed to evaluate the impact of surface stabilizers, generally used to reinforce roads, rivers, and slopes of roads, applied using surface curtain walls on aging reservoirs. The DST results indicate that when the surface stabilizer was mixed with in-situ soil, the increase in cohesion was the highest at a mixing ratio of 9%. No changes in the friction angle were evident; therefore, 9% was determined to be the optimal mixing ratio. In addition, the model test and simulation analysis showed that when 9% of the surface stabilizer was mixed and applied to the aging reservoir, the seepage quantity of water and the saturated area were reduced by approximately 42% and 73%, respectively. Moreover, the comprehensive analysis of results showed that the grouting method could be completely replaced by surface stabilizers applied through surface curtain walls because the technique could secure stability by decreasing the seepage in the aging reservoir.

• 한국지반공학회논문집
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• 제21권1호
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• pp.29-41
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• 2005

우리나라의 소규모 항만이나 어항인 경우에 설계파는 낮지만 지반조건이 좋지 않은 경우가 많기 때문에 기존의 방파제 축조공법을 이용할 경우 비용이 커질 뿐만 아니라 건설재료의 확보가 어려운 실정이다. 따라서 설계파가 비교적 낮은 경우에 저렴하게 적용할 수 있는 새로운 형식의 방파제에 대한 수요가 증가함에 따라, 본 연구에서는 지반에 대한 특별한 처리 없이 간편하게 설치할 수 있는 가로널식 방파제를 개발하였다. 이 논문은 개발된 가로널식 방파제에 대해 방파제의 근입깊이 및 보강기법, 배치 형태 등 다양한 조건에 따른 방파제의 횡방향 거동을 분석한 것으로 이를 위해 느슨한 모래지반을 대상으로 모형 토조실험을 수행하였다. 실험 결과, 근입깊이 이외에도 경사 버팀보나 앵커등 보강재의 효과 및 방파제 배치 형식에 따른 경향을 확인하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 추계 학술논문 발표대회
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• pp.213-214
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• 2012

This study is about the assessment of utilization possibility as a material for cementation of ground which is necessary for the reinforcement of soft ground by making environment-friendly inorganic composite utilizing inorganic recycled resources, and it was verified that it showed higher uniaxial compressive strength than the existing cementitious ground solidifier when it was applied as a combination material for soft ground such as dredge reclaimed land, and since an inorganic composite utilizing recycled resources such as high calcium fly ash and blast furnace slag etc. does never use cement, it is considered that it would be safe in the issue of a hexavalent chromium that was recognized as a problem of a cementitious solidifier.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 가을 학술발표회 논문집
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• pp.398-403
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• 2002

The low slump mortar grouting is widely used in reinforcement of structural foundation and ground improvement in soft ground. It also has merit that construction is possible in insufficient space. In this study, the main purpose is to evaluate effects for contiguous structures that can be happened along with soft ground improvement by the low slump mortar grouting. To estimate these effects, numerical analysis using finite difference method was applied. It was performed to analyze settlement, upheaval and horizontal displacement of surrounding ground and to measure horizontal stress variation by the first and the second grouting in the pile foundation.