• 한국철도학회논문집
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• 제12권1호
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• pp.55-64
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• 2009

콘크리트궤도는 유지보수상의 장점으로 인하여 자갈궤도를 급속히 대체하고 있다. 반면에 보수보강이 어렵기 때문에 매우 엄격한 설계와 시공기술이 필요하며 이러한 기술을 만족하기 위해서는 평가기술 또한 뒷받침이 되어야 한다. 본 논문에서는 이와 같이 시공 및 유지보수의 핀 평가기술을 확보하기 위한 방안으로서 탄성파를 이용하는 비파괴조사기법을 다양하게 적용하였다. 사용된 기법은 SASW시험, 임팩트에코시험, 연속임팩트에코시험이다. 시험은 49개의 프리캐스트 판넬의 강성구조와 충진성능을 평가하는 목적으로 총 5,353회에 걸쳐 수행되었다. 적용 결과, 콘크리트재료 자체의 비균질성으로 인하여 탄성파시험의 적용 및 분석이 제한적이지만 본 논문에서 목적하는 슬래브의 강성구조과 충전성(공극)에 대한 신뢰성 있는 조사 결과를 얻을 수 있을 것으로 나타났다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1990년도 PROCEEDINGS OF THE FIRST KOREA-JAPAN JOINT GEOTECHNICAL SEMINAR ON EXCAVATION and TUNNELING IN URBAN AREAS
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• pp.25-34
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• 1990

For the construction of twin single track subway tunnels by NATM within close proximity of existing vehicle underpass in the highly congested area of downtown Seoul, finite element analyses were performed to evaluate the ground responses during tunnelling and also the stability and safety of the underpass structure and subway tunnels. Results of the analyses indicated the need to improve the soil beneath the underpass, and pre-grouting was carried out prior to the tunnel excavation. During tunnel construction field measurement program was implemented to confirm the results of anslyses and to control the tunnel construction procedures, thus ensuring stability of the existing structres.

• 터널과지하공간
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• 제28권6호
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• pp.528-546
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• 2018

국내외 터널공사에서 TBM의 적용사례가 지속적으로 증가하고 있으며, 특히 도심지터널과 하 해저터널의 시공에서 TBM 굴착 공법은 발파공법에 비해 여러 장점을 가지므로 우선적으로 고려되는 경우가 많다. 도심지와 하 해저 터널에서는 연약지반 혹은 특수지반을 조우할 가능성이 높으며, 이러한 지질특성으로 인한 지반보강과 지반개량을 필수적으로 고려하여야 한다. 터널공사에서 지반 보강 및 개량 공법으로 그라우팅 공법이 널리 활용되고 있다. TBM 공법이 가지는 고속굴진, 굴진안정성, 환경피해 최소화 등 장점을 극대화하기 위해서 특수지반 조우 시 지반조건에 적합한 그라우팅재료와 공법을 선정하는 것이 공사비와 공기의 증가를 줄이는데 매우 중요하다. 하지만 현재까지 국내에서는 특수지반에 대한 보강 체계가 정립되어 있지 않으므로 본 논문에서는 특수지반에서의 효율적인 시공을 위한 기초연구로서, 일반적인 암반 토사 지반조건 이외 특수지반에서 쉴드TBM 굴착 시 적용될 수 있는 그라우팅 공법에 대하여 고찰하였다. 또한 국내외에서 특수지반 쉴드TBM 시공사례로부터 지반조건에 따른 그라우팅 공법의 적용성을 분석하여 정리하였다. 향후 쉴드TBM을 적용한 터널 시공 시 지반조건에 따른 적합한 그라우팅 재료와 공법을 선정하는데 기초자료로 사용될 수 있을 것으로 기대된다.

• Geomechanics and Engineering
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• 제15권5호
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• pp.1029-1038
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• 2018

A superposition-iteration (S-I) model is proposed to simulate the jet grouting pre-reinforcing impact for a shallow-buried tunnel. The common model is deduced by theoretical (force equilibrium) analysis and then transformed into the numerical formulation. After applying it to an actual engineering problem, the most obvious deficiency was found to be continuous error accumulation, even when the parameters change slightly. In order to address this problem, a superposition-iteration model is developed based on the basic assumption and superposition theory. First, the additional deflection between two successive excavation steps is determined. This is caused by the disappearance of the supporting force in the excavated zone and the soil pressure in the disturbed zone. Consequently, the final deflection can be obtained by repeatedly superposing the additional deflection to the initial deflection in the previous steps. The analytical solution is then determined with the boundary conditions. The superposition-iteration model is thus established. This model was then applied and found to be suitable for real-life engineering applications. During the calculation, the error induced by the ill-conditioned problem of the matrix is easily addressed. The precision of this model is greater compared to previous models. The sensitivity factors and their impact are determined through this superposition-iteration model.

• Geomechanics and Engineering
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• 제14권5호
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• pp.429-437
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• 2018

In order to reduce deformation of roadway floor heave in deep underground soft rockmass, four support design patterns were analyzed using the Fast Lagrangian Analysis of Continua (FLAC)3D, including the traditional bolting (Design 1), the bolting with the backbreak in floor (Design 2), the full anchorage bolting with the backbreak in floor (Design 3) and the full anchorage bolting with the bolt-grouting backbreak in floor (Design 4). Results show that the design pattern 4, the full anchorage bolting with the bolt-grouting backbreak in floor, was the best one to reduce the deformation and failure of the roadway, the floor deformation was reduced at 88.38% than the design 1, and these parameters, maximum vertical stress, maximum horizontal displacement and maximum horizontal stress, were greater than 1.69%, 5.96% and 9.97%. However, it was perfectly acceptable with the floor heave results. The optimized design pattern 4 provided a meaningful and reliable support for the roadway in deep underground coal mine.

• 화약ㆍ발파
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• 제13권3호
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• pp.19-30
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• 1995

NATM as method of tunneling has been applied to construction of domestic subway, roads, rail way, water way etc. Accordingly, we have NATM's many drafts and constructional results, but many problems and accidents have occurred under construction of tunnel using NATM for shortage of technical data. Poorness of constructional improvement, systemic inconsistency etc. Especially, everyone was shocked at Gupo's train wrecking accident lately. The purpose of this thesis is presentation of means for setting technical problems, by looking into Gupo's train wrecking accident and home records that applying NATM in tunneling failed, to minimize future safety accidents we find that the general problems of home fifteen sites having occured accidents is badly geological survey, nonconfirmationi of base rock's state, formal measuring management, shortage of specialists, systemical discrepancy and that disregarding NATM's rules makes general problems. The results of this study are Summarised as follows : 1. We advise repletion of design standards to practice crosshole test for confirming connected rock base on vertical section of tunnel. 2. We advise to practice pre0boring and pre-grouting for a weak layer difficult in applying NATM. 3. We advise systemic improvements that field servicer can construct tunnel of his own free will considering base rock's state at tunnel . 4. We advise that specialist, who can make a conduct and supervise above mentioned items as well as measuring management, should be posted at field.

• 한국안전학회지
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• 제9권4호
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• pp.92-102
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• 1994

NATM as method of tunneling has been applied to construction of domestic subway, roads, rail way, water way etc. Accordingly we have NATM's many drafts and constructional results, but many problems and accidents have occurred under construction of tunnel using NATM for shortage of technical data, poorness of constructional improvement, systemic inconsistency etc. Especially, everyone was shocked at Gupo's train wrecking accident lately. The purpose of this thesis is presentation of means for settling technical problems, by looking into Gupo's train wrecking accident and home records that applying NATM in tunneling failed, to minimize future safety accidents we find that the general problems of home fifteen sites haying occured accidents is badly geological survey, nonconfirmation of base rock's state, formal measuring management, shortage of specialists, systemical discrepancy and that disregarding NATM's rules makes general problems. The results of this study are summarised as follows ; 1. We advise repletion of design standards to practice crosshole test for confirming connected rock base on vertical section of tunnel. 2. We advise to practice pre-boring and pre-grouting for a weak layer difficult in applying NATM. 3. We advise systemic improvements that field servicer can construct tunnel of his own free will considering base rock's state at tunnel. 4. We advise that specialist, who can make a conduct and supervise above mentioned items as well as measuring managements, should be posted at field.

• 터널과지하공간
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• 제25권4호
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• pp.383-396
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• 2015

모래자갈층에서 터널굴착 시 발생하는 지표침하에 의해 지상빌딩에 발생하는 손상도를 분석하였다. 모래자갈층의 두께와 터널까지의 심도는 약 20m이고 터널의 폭과 높이는 각각 12m, 8.6m이다. 터널은 막장전방을 3열의 강관다단그라우팅으로 보강하면서 시공하였다. 터널시공 중에 빌딩주변 36개소에서 지표침하를 계측하였고 이를 이용하여 3차원 지표침하면을 구하고 빌딩의 위치에 따라 처짐비와 수평변형율로 빌딩의 손상도를 평가하였다. 시공 중 계측된 지표침하는 약 1~4mm로 작았고 빌딩은 수평압축변형을 받는 상태가 되어 빌딩에 손상이 발생하지 않았다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.465-474
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• 2005

This paper presents the interaction effect between tunneling and groundwater on tunnel behavior. A parametric study is then conducted on the various tunneling situations frequently encountered in Seoul area using a 3D stress-pore pressure coupled finite-element model with emphasis on the effects of ground and lining permeabilities. It is shown that the ground and lining responses are significantly influenced by the relative permeability between the ground and the lining, and that the circumferential pre-grouting is effective in minimizing the tunnelling and groundwater interaction.

• 한국구조물진단유지관리공학회 논문집
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• 제13권6호통권58호
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• pp.192-203
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• 2009

본 연구는 경부고속철도(대구~부산) 도심통과 노반신설 공사중 기존 부산지하철 1호선 및 부산지하철 2호선 구간에 대한 안정성에 관한 연구로서 현장조사를 실시하여 대상시설물의 외관상태, 품질상태 및 내구성능 등을 평가하고 MIDAS/GTS를 이용한 수치해석을 통해 대상시설물 및 본선터널의 안정성을 검토하는데 그 목적이 있다. 지하수위 하에서 터널이 시공되는 기본 메카니즘과 3차원 유한요소해석 응력-간극수압 연계해석을 수행한 후 라이닝 작용하중, 막장안정성, 지표침하 등 지하수와 터널굴착의 상호관계를 고찰하였다. 수치해석의 결과 1, 2호선의 최대침하, 부등침하, 라이닝응력 등은 허용치 이내이며 손상 정도는 무시할 수 있는 정도의 경미한 것으로 나타나고 있다. 그러나 실제 터널 시공시 막장거동을 최소화하기 위하여 필요시 Pre-Grouting을 시행하여 터널 굴착시 터널내 유출수를 최소화하는 것이 필요할 것으로 판단된다.