• 한국지반공학회논문집
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• 제16권6호
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• pp.127-139
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• 2000

In the study, an expert system was developed to predict the safety of tunnel and select proper tunnel reinforcement system using fuzzy quantification theory and fuzzy inference rule based on tunnel information database, For this development, many tunnelling sites were investigated and the applied countermeasures were studied after building tunnel database. There will be benefit for the deciding tunnel reinforcement method in the case of poor ground condition. The expert system developed in the study has two main parts, pre-module and post-module. Pre-module is used to decide input items of tunnel information based on the tunnel face mapping information which can be easily obtained in in-situ site. Then, using fuzzy quantification theory II, fuzzy membership function is composed and tunnel safety level is inferred through this membership function. Post-module is used to infer the applicability of each reinforcement methods according to the face level. The result of the predicted reinforcement system level was similar to measured ones. In-situ data were obtained in three tunnel sites including subway tunnel under Han River. Therefore, this system will be helpful to make the mose of in-situ data available and suggest proper applicability of tunnel reinforcement system to development more resonable tunnel support method without dependance of some experienced experts opinions.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.101-108
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• 2000

In this study, an expert system was developed to predict the safety of tunnel and choose proper tunnel reinforcement system using fuzzy quantification theory and fuzzy inference rule based on tunnel information database. The expert system developed in this study have two main parts named pre-module and post-module. Pre-module decides tunnel information imput items based on the tunnel face mapping information which can be easily obtained in-situ site. Then, using fuzzy quantification theory II, fuzzy membership function is composed and tunnel safety level is inferred through this membership function. The comparison result between the predicted reinforcement system level and measured ones was very similar. In-situ data were obtained in three tunnel sites including subway tunnel under Han river, This system will be very helpful to make the most of in-situ data and suggest proper applicability of tunnel reinforcement system developing more resonable tunnel support method from dependance of some experienced experts for the absent of guide.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.1343-1350
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• 2005

In this study, the whole deformation conditions of domestic old tunnels and reinforcement methods for deformation tunnels were investigated and analysed, and the present conditions, occurrence cause and reinforcement methods of cavity behind the tunnel lining were investigated and analysed comprehensively. The deformation causes of domestic old tunnels could be classified in three kinds : change of earth pressure operating tunnel ground, material problem of concrete lining, mistake of design and construction. As a result of analysis, the tunnel deformation was occurred by not specific cause but various cause As a result of investigation for 455 domestic tunnel data, more than 70% of the tunnel deformation was related to leakage and the other deformation cause also accompanied leakage mostly. An applied reinforcement method was related to leakage and flood prevention measures, but application of reinforcement method for boundary area between tunnel and ground and tunnel periphery which influence on the tunnel stability was still defective. The cavity of domestic old tunnel occupied about 16% of the total tunnel length and about 68% of cavity was located in the crown of tunnel, and besides, the occurrence cause of cavity was analysed to design, construction and management cause. The filling method for cavity using filling material was comprehensively appling to cavity behind tunnel lining.

• 한국터널공학회:학술대회논문집
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• 한국터널공학회 2005년도 학술발표회 논문집
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• pp.270-281
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• 2005

An especial attention for old tunnel safety is required on increasing of The various tunnel recently. Specially, the lining investigation method of the old tunnel will be able to presume condition of concrete lining indirectly. Because it is many restriction thought of environment and ground condition investigation method of tunnel lining rear. This study carried out section & convergence measurement of part which was deformed in tunnel lining. It had been observed for the change of tunnel behavior with a continuous measurement. It has been analyzed for a cause of tunnel deformation and inspected for the effect after a repair-reinforcement to tunnel compared with the effect before those by structure analysis. By establishing automatic measurement system after repair-reinforcement to tunnel, it would be accomplished to convergence measurement continually. As a result, it was observed that deflection and deformation of tunnel was convergent. but it should be followed to a continuous maintenance because of unstable ground condition, cause of inner tunnel, environment. The railroad tunnel which was executed a reinforcement of the tunnel lining must investigate the close condition of reinforcement lining and concrete lining.

• 한국터널지하공간학회 논문집
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• 제20권3호
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• pp.625-639
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• 2018

본 연구는 터널 갱구부의 복잡하고 다양한 지형조건과 공학적인 강도특성이 불량한 토사 및 풍화암이 깊은 심도로 분포하는 조건에 대하여 터널 굴착 중 안정성확보를 위하여 보강되는 보조공법의 보강방법에 관한 논문이다. 기존 터널 갱구부 보조공법(강관보강 그라우팅, Ø60.5 mm, Ø114.3 mm)은 장심도 수평시공이 곤란하여 중첩보강 조건으로 시공되고 있다. 근래, 고강성의 대구경 강관 및 수평방향 장심도(L = 30.0~50.0 m) 시공기술이 개발됨에 따라, 터널 갱구부의 지층 및 지반조건에서 보조공법의 보강방법에 대한 공학적인 검토를 수행하여 효과적인 보강방법의 평가가 필요한 상황이다. 따라서 터널 보조공법 무보강 조건, 기존 중첩보강 조건 및 수평보강 조건과 터널 갱구부의 지반조건을 매개변수로 하여 3차원 연속체 수치해석(Midas GTS NX 3D)을 수행하여 보강효과를 검토한 결과, 보조공법 수평보강조건이 변위(천단침하 및 내공변위) 및 지보재 응력이 가장 작게 발생됨에 따라, 보강효과가 가장 큰 것으로 검토되었다. 본 연구 결과를 토대로, 터널 갱구부 현장에 장심도 대구경 강관 수평보강 그라우팅을 설계 및 시공한 결과, 터널 갱구부 변위 및 지보재 응력은 허용값 이내에서 발생되어 충분한 안정성이 확보되는 것으로 검토되었다. 또한, 터널 갱구부의 지반굴착을 최소화함에 따라, 친환경적인 터널 갱구부 형성이 가능한 것으로 파악되었다.

• 자연, 터널 그리고 지하공간
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• 제1권2호
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• pp.59-71
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• 1999

Recently, many deformations in tunnel such as crack and leakage were occulted. Specially, the defects of tunnel lining have been a serious problem in safety and stability many repair works for maintenance in tunnel have been carried out. Therefore, it is necessary to estimate the structural cracking for countermeasure in deformed tunnel and to investigate on the characteristics of lining system and the soundness of tunnel. In this study model tests for tunnel lining were carried out using test apparatus and centrifuge, In the direct loading test, the prototype was Kyungbu high-speed railway tunnel and the scale is 1/10, and lining models were made of concrete. Test conditions included load conditions such as direction, shape and type, lining conditions such as single and double lining, thickness, and reinforcement. In centrifuge model test, the prototype was Seoul subway tunnel and the scale is 1/100, and lining models were made of aluminum and hydrostone. Test conditions included tunnel defects such as thickness shortage. behind cavity and longitudinal cracks, reinforcement methods such as epoxy, grouting and carbon sheet. From these model tests , the characteristics of deformation and failure for tunnel lining were estimated, and the structural behaviors of deformed lining and the effects of repair and reinforcement for tunnel lining were researched.

• Geomechanics and Engineering
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• 제33권5호
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• pp.463-475
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• 2023

Tunnel construction activity, conducted mainly in mountains and within urban centres, causes soil settlement, thus requiring the relevant management of slopes and structures as well as evaluations of risk and stability. Accordingly, in this study we performed a three-dimensional finite element analysis to examine the behaviour of piles and pile cap stability when a tunnel passes near the bottom of the foundation of a pile group connected by a pile cap. We examined the results via numerical analysis considering different conditions for reinforcement of the ground between the tunnel and the pile foundation. The numerical analysis assessed the angular distortion of the pile cap, pile settlement, axial force, shear stress, relative displacement, and volume loss due to tunnel excavation, and pile cap stability was evaluated based on Son and Cording's evaluation criterion for damage to adjacent structures. The pile located closest to the tunnel under the condition of no ground reinforcement exhibited pile head settlement approximately 70% greater than that of the pile located farthest from the tunnel under the condition of greatest ground reinforcement. Additionally, pile head settlement was greatest when the largest volume loss occurred, being approximately 18% greater than pile head settlement under the condition having the smallest volume loss. This paper closely examines the main factors influencing the behaviour of a pile group connected by a pile cap for three ground reinforcement conditions and presents an evaluation of pile cap stability.

• Geomechanics and Engineering
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• 제28권2호
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• pp.145-155
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• 2022

Safety is a most important parameters in underground railway transportation; Also stability of underground tunnel is very important in tunneling engineering. Design of a reliable support system requires an evaluation of both ground demand and support capacity. Iran's traditional railway tunnels are mainly supported with masonry structures or unsupported in high quality rock masses. A decrease in rock mass quality due to changes in groundwater regime creep and fatigue in rock and similar phenomena causes tunnel safety to decrease during time. The case study is an old tunnel in Iran, called "Keshvar"; it is more than 50 years old railway organization. In operating this Tunnel, until the several problems came up based on stability and leaking water. The goal of study is evaluation of the various reinforcement systems for supporting of the tunnel. The optimal selection of the reinforcement system is examined using TOPSIS Fuzzy method in light of the looming and available uncertainties. Several factors such as; the tunnel span, maintenance, drainage, sealing, ventilation, cost and safety were based to choose the method and system of designing. Therefore, by identifying these parameters, an optimal reinforcement system was selected and introduced. Based on optimization system for analysis, it is revealed that the systematic rock bolts and shotcrete protection had a most appropriate result for these kind of tunnel in Iran.

• 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 1999년도 가을 학술발표회 논문집
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• pp.201-208
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• 1999

The NATM(New Austrian Tunnelling Method) has been used for tunnelling since 1980's. But Collapses of tunnel under construction take place frequently, especially at urban areas because of adjacent buildings, underground conduits and traffic loads. This paper is a case study on the reinforcement method of subway tunnel at urban areas. In this study, ground inspection, geological investigation, laboratory test and numerical analysis by means of FDM program were carried out. The tunnel excavation was stopped because of over excessive brake of tunnel crown and shotcrete was installed to prevent deformation of adjacent ground as the temporary method. From the result of field survey and geological investigation, it is found that the soft weathered soil was distributed to the ground of tunnel invert unlike original investigation. The results of the analysis and the study show that the SGR(Space Grouting Rocket) method and Umbrella method can be applied for the stability of tunnel excavation and in addition the reinforcement of concrete lining is required for long-term stability of tunnel.