• 터널과지하공간
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• 제14권4호
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• pp.275-286
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• 2004

본 논문에서는 신규 터널노선과 교차하는 폐터널의 보강방식을 결정하기 위하여 의사결정기법을 검토하였고, 여러 가지 의사결정기법들 중에서 설문조사의 과정을 최소화 하고, 조사항목 별 정성적ㆍ정량적 특성을 모두 반영할 수 있도록 쌍대비교와 퍼지근사추론을 이용하여 폐터널의 보강방식에 대한 적정성을 평가하여 보았다. 페터널 보강방식을 선정하기 위하여 4개의 주 요인들 즉, 시공성, 경제성, 안전성, 유지관리성을 평가의 수단으로 사용하였고, 간단한 설문조사와 쌍대비교행렬을 이용하여 4가지 주 요인들의 가중치를 결정하였다. 퍼지근사추론은 4개의 주 요인별 평가점수를 산정 하는데 사용되어졌고, 이 결과들에 가중치를 반영하여 최종적인 폐터널의 보강방식을 선정할 수 있었다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 가을 학술발표회 논문집
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• pp.44-51
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• 2002

The construction road and addition work are increasing now. Therefore, slope stability is important in construction slope on the fault and fractured zone. Rock bolt method, soil nailing method and anchor method are applied to reinforcement method of slope. This paper is the study for construction management on reinforcement method of slope.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.529-536
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• 2003

In domestic case occurrence of cut slopes according to construction and expansion of road is necessary more than 70% of country has been consisted of mountain area. In the case of Kang-won Do, there are much mountains locals in road wiping away a disgrace and expanded and slant is connoting collapse danger of incision side by each kind calamity being urgent. When route alteration enforces disadvantageous road extension, stability examination and processing way about large slope happened are serious. During road extension work in the Kang-won DO secure stability for falling rock of road slope and failure that happen and established suitable reinforcement and countermeasure in reply in necessity. The Slope is divided rock slope and soil slope, and then in order to analysis soil slope apply LEM theory. And rock slope examined stability about stereographic projection and wedge failure. Is going to utilize in reinforcement and failure prevention if it is efficient cutting as reinterpreting stability and secure stability and wish to consider effective and robust processing plan of great principle earth and sand side, and present countermeasure inside with these data hereafter applying suitable reinforcement countermeasure about unstable section.

• 한국터널지하공간학회 논문집
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• 제7권1호
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• pp.51-61
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• 2005

터널의 주변지반을 보강할 경우 지반의 강도정수는 변화한다. 그러므로 보강된 터널주변지반의 지보, 보조 및 보강, 굴착설계 시 보강된 주변지반의 강도기준에 대하여 고려하여야 할 것이다. 따라서 본 논문에서는 터널의 주변지반을 보강할 경우 터널주변지반의 복합거동에 대한 연구로써 간편 터널 지보/보강 설계법과 보강된 주변지반의 강도정수변화에 대하여 이론적 및 실험적으로 연구하였으며, 또한 터널주변 강도정수 변화 결과에 따른 복합항복함수에 대해서도 제시하였다. 연구결과, 록볼트의 경우에는 터널주변지반의 내부마찰각의 증가보다는 점착력의 증가에 많은 영향을 준다는 것을 알 수 있었다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.405-410
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• 2009

This paper presents a case study that achieved both of serviceability and safety of the building through soil reinforcement and restoration around foundations subjected to serious differential settlement using D-ROG method. The building which has one basement floor and three ground floors is founded on soft ground and differential settlement occurred to the maximum extent of 678mm. The foundation type of the building is a independent mat foundation. Soil profiles consist of landfill layer, alluvial layer, weathered rock, and soft rock. The bearing layer consisting of gravel and weathered rock is located 16.0~17.0m below the bottom of the building. As a result of soil reinforcement and restoration, the recovery ratio of more than 90% can be attained with the maximum set-up of 657mm.

• Geomechanics and Engineering
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• 제20권1호
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• pp.67-73
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• 2020

With the increasing number of underground projects, the problem of rock-water coupling catastrophe has increasingly become the focus of safety. Grouting reinforcement is gradually applied in subway, tunnel, bridge reinforcement, coal mine floor and other construction projects. At present, cement-based grouting materials are easy to shrink and have low strength after solidification. In order to overcome the special problems of high water pressure and high in-situ stress in deep part and improve the reinforcement effect. In view of the mining conditions of deep surrounding rock, a new type of cement-based reinforcement material was developed. We analyses the principle and main indexes of floor strengthening, and tests and optimizes the indexes and proportions of the two materials through laboratory tests. Then, observes and compares the microstructures of the optimized floor strengthening materials with those of the traditional strengthening materials through scanning electron microscopy. The test results show that 42.5 Portland cement-based grouting reinforcement material has the advantages of slight expansion, anti-dry-shrinkage, high compressive strength and high density when the water-cement ratio is 0.4, the content of bentonite is 4%, and the content of Nano Silica is 2.5%. The reinforcement effect is better than other traditional grouting reinforcement materials.

• Geomechanics and Engineering
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• 제14권4호
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• pp.345-354
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• 2018

Currently, layered geogrid method (LGM) is the commonly practiced technique for reinforcement of slopes. In this paper the geogrid-box method (GBM) is introduced as a new approach for reinforcement of rock-soil slopes. To achieve the objectives of this study, a laboratory setup was designed and the slopes without reinforcements and reinforced with LGM and GBM were tested under the loading of a circular footing. The effect of vertical spacing between geogrid layers and box thickness on normalized bearing capacity and failure mechanism of slopes was investigated. A series of 3D finite element analysis were also performed using ABAQUS software to supplement the results of the model tests. The results indicated that the load-settlement behavior and the ultimate bearing capacity of footing can be significantly improved by the inclusion of reinforcing geogrid in the soil. It was found that for the slopes reinforced with GBM, the displacement contours are widely distributed in the rock-soil mass underneath the footing in greater width and depth than that in the reinforced slope with LGM, which in turn results in higher bearing capacity. It was also established that by reducing the thickness of geogrid-boxes, the distribution and depth of displacement contours increases and a longer failure surface is developed, which suggests the enhanced bearing capacity of the slope. Based on the studied designs, the ultimate bearing capacity of the GBM-reinforced slope was found to be 11.16% higher than that of the slope reinforced with LGM. The results also indicated that, reinforcement of rock-soil slopes using GBM causes an improvement in the ultimate bearing capacity as high as 24.8 times more than that of the unreinforced slope.

• 터널과지하공간
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• 제15권6호
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• pp.425-431
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• 2005

본 연구에서는 폐탄광 갱도를 이용한 갱도 전시장의 안정성 평가를 위해서 다양한 조사와 시험을 실시하였다. 이 광산의 일부 갱도는 1999년 폐광 후 관광용의 갱도전시장으로 이용되어지고 있다. 갱도전시장 주 갱도의 규격은 폭이 약 5 m에 높이가 3 m이며 갱도 연장이 230 m이다. 갱도를 구성하고 있는 암반은 흑색 셰일 및 석탄층 그리고 석회암으로 구성되어 있다. 갱도조사결과 갱도는 두 개의 단층과 교차하는 것으로 나타났다. 본 연구에서는 정밀 지질 및 암반조사를 통해 경험적 방법에 의한 안정성평가를 실시하고 보강의 필요성 등을 결정하였다. 그 결과를 토대로 수치해석을 실시하여 갱도 주변 암반의 전반적인 안정성과 보강(안)의 적절성 여부를 검토하였다. 갱도전시장 내부 주요지점의 RMR값과 Q값은 보통(Fair)과 양호(good)의 등급을 나타내었다. Q값을 토대로 산정한 각 지점의 보강안은 무지보나 systematic toiling으로 나타났다. 2차원 전산해석결과 전반적으로 갱도전시장의 안정성은 확보된 것으로 판단되나 일부 불안정 블록에 대한 추가 보강이 필요할 것으로 판단된다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1149-1156
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• 2011

A rockbolt is one of the most important reinforcement of on-site soil, as with the shotcrete and steel rib. The rockbolt by setting within the tunnel can prevent the deformation of the ground profile; furthermore it improves the structural behavior of soil and rock. In general, the rockbolt is mainly used with reinforced steel. However, steel pipe or the materials with the same strength can be used depending on the soil conditions, ground water outflow condition, and the surrounding of applying location. In Korea, most tunnel construction sites have used cement mortar or resin for steel reinforcement on the rock. Due to the ground water outflow in the construction site, the usability of steel reinforcement is poor and it requires curing time especially after installation. To improve exist above problems, this study introduces the development of a swelled steel pipe rockbolt, as well as presents the field testing and performance results.

• 한국농공학회지
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• 제45권6호
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• pp.172-182
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• 2003

In this study, the back analysis was performed by means of stereo-net, plane failure and block failure method to collapsed fields among the rock slopes designed by standardized criterion, and the internal frictions from the back analysis were compared with those used to reinforcement design. It was concluded that in the result of the analysis by means of stereo net, plain failure and block failure methods, the internal frictions used to re-design of collapsed slope underestimated 10$^{\circ}$, 5$^{\circ}$ and 10$^{\circ}$ in average. At present, the internal friction on the design is used the experience value according to the state of weathering, but internal friction angle by the back analysis on collapsed slope with various methods were more reliable values than those from the present method. And it was concluded that re-design was made extravagantly because the internal friction used to re-design for reinforcement of the collapsed slope was less than back analysis.