• Proceedings of the Korean Geotechical Society Conference
• /
• 2001.03a
• /
• pp.121-128
• /
• 2001

This is a case study of stability analysis and reinforcement design for the tunnel where the collapse of the entrance slops occured along the fault zone developed in the bed rock. According to the site investigation, the main factor of sliding is the influence of fault gouge and heavy rainfall. Considering the in-situ condition, the versatile reinforcement methods is needed, and so the close investigation on the site area was accompanied with the stability analysis of tunnel and slops. The FRP(Fiberglass reinforced plastic) grouting method improved the defect of Steel Umbrella Arch Method, such as oxidation, low work efficiency, the material's heavy weight, is adapted as the reinforcement methods.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2000.11a
• /
• pp.143-150
• /
• 2000

A field test performance of FRP-Grouting method at a collapsed slope were carried out to verify the improving effect. The results are summerized in this paper.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2001.10b
• /
• pp.60-76
• /
• 2001

The grout-effect evaluation of the ground reinforcement technique, which has been widely applied to civil engineering and construction fields, is not established for the guidelines of choosing the efficient evaluation method, and in fact the expects have little effort to determine the reinforcement effect quantitively. This paper presents some results a field test performance of FRP pressure grouting method at a collapsed slope were carried out to verify the improving effect.

• 도로교통
• /
• s.87
• /
• pp.56-63
• /
• 2002

• Proceedings of the Korean Geotechical Society Conference
• /
• 2000.03b
• /
• pp.199-206
• /
• 2000

The grout-effect evaluation of the ground reinforcement technique, which has been widely applied to civil engineering and construction fields, is not established for the guidelines of choosing the efficient evaluation method, and in fact the experts have little effort to determine the reinforcement effect quantitatively. The evaluation of the grout was carried out by experiments on core specimen and drilling, which is impossible to evaluate grout-reinforcement effect quantitatively. This paper presents an example on verification of FRP grout-effect using geophysical prospecting on ground surface, which is 2D resistivity survey that easily visualize survey results with color graphics and seismic refraction method that interprets the subsurface seismic velocity structure.

• Korean Journal of Agricultural Science
• /
• v.35 no.2
• /
• pp.213-223
• /
• 2008

The instability of rock slopes caused by heavy rainfall and soil mass sliding needs the preventable and reinforcing method. The most important factor for the stability is the shear strength available in the planar part of the failure surface, which shows that a progressive failure takes place and a reinforcing of rock slope using FRP grout is effectively available. In this study, a grouting bolting interval predictions by limit equilibrium analysis and Matlab mathematical computer codes in several cases is presented for FRP reinforced rock slope. The proposed mathematical computer code can be easily applied for seeking properly FRP grout intervals prior to design and execute a reinforcement of a rock slope in practice.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2000.11b
• /
• pp.155-180
• /
• 2000

The pattern of domestic slope construction has been steadily changed from the simpled and small-scale to the large-scale and complicated one, frequently near the existing structures, as the density of population and the traffic increases. In some cases, the slopes become steeper and larger due to the road improvement and construction. For the rock slope, the existence of discontinuity cannot be disregarded and acts as an important factor on the slope stability. Most of the existing methods for stabilizing the slope were focused on reducing the slope angle. Under the specific geographic condition, it is necessary to concentrate more efforts on the research and development of supporting system for the slope stability. As a supporting system, it is often very advantageous to use the FRP pipe grouting method that is similar to the existing soil nailing method or the rock bolting method but uses the high strength FRP pipe as a principal reinforcement in place of steel bar. Through the FRP pipe, the grout material can be injected into the rock mass to improve its shear strength to the required value. .In this study, the characteristics of FRP are investigated by the laboratory tests and the field tests. And, the practical aspects of FRP method are reviewed and analyzed.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2001.10b
• /
• pp.44-58
• /
• 2001

FRP(Fiberglass Reinforced Plastic)관을 이용한 사면보강은 천공 후 그라우트재에 압력을 가하여 그라우트재의 천공홀 충전뿐만 아니라 지반으로의 침투주입 효과를 일으켜, 전체적인 보강력 증대를 기대하는 공법이다. 이런 특성을 설계에 반영하기 위해서는 구조재료인 FRP관 자체에 의한 지반보강효과 뿐만 아니라 그라우팅에 따른 지반강도의 증진효과를 정량적으로 평가하는 것이 선행되어야 하나 아직까지는 이에 대한 연구가 부족한 실정이다. 따라서 대상지반을 토사와 암반사면으로 구분하여 각각의 보강효과를 확인하고자 현장시험 및 수치해석을 실시하였으며, 이로부터 지반종류에 따른 보강특성과 합리적인 설계를 위한 설계인자를 추출하고자 하였다.

• The Journal of Engineering Geology
• /
• v.23 no.3
• /
• pp.283-292
• /
• 2013

A calcareous rock slope failed during excavation of the slope for construction of a tunnel entrance. The slope is located at the construction site for widening highway in Yeongwol, Korea. Field surveys, laboratory tests, and numerical analyses were performed to determine the reason for the slope failure. The numerical analysis revealed that the safety factor of the slope before construction of the entrance was less than 1, and that this decreased after construction. After construction of the entrance, the sliding zone of the slope increased and slope stability decreased because the shear strain and plastic zone in the slope over the tunnel entrance showed an increase relative to the lower part of the slope. To enhance the stability of the slope for construction of the tunnel entrance, countermeasures such as rock bolts, rock anchors, and FRP (Fiber glass Reinforced Plastic) grouting were adopted in light of the field conditions. Serial field monitoring performed to confirm the reinforcing effects of the adopted countermeasures revealed a small amount of horizontal deformation of the slope soils, most of the elastic deformation that can regain its former value. In addition, the axial forces of the rock bolt and anchor were more strongly affected by slope excavation during construction of the tunnel entrance than by tunnel excavation or the rainy season, and the axial forces tended to converge after excavation of the tunnel. Therefore, we can confirm that the slope is currently safe.