그라우팅 보강에 의한 터널 라이닝 하중 연구 = (A) Study of tunnel lining load induced by grouting reinforcement

다국어 초록 (Multilingual Abstract)

Backfill and Consolidation Grouting is one of the major reinforcing methods that enhance the stiffness of the ground and make sure the whole tunnel stability. However, the study of grouting effect on tunnel lining system has been unsatisfied yet.
In this study, Field measurements such as Pressure Meter Test and Lugeon Test, and also in-situ monitoring using strain gauges and pressure cell were executed in detail to analyze the grouting effect.
Prediction of lining loads and rock relaxation load due to the tunneling was discussed and calculated because this was major issue to be addressed in the lining design.
Numerical analysis is one approach to the tunnel design. To have a better understanding of the grouting effect and to check the lining stability considering the grout pressure, structural analysis using the program SAP2000 was analyzed also.
The followings are the results in conclusion.
(1) In case of this study, the modulus of elasticity due to grouting reinforcing was increased up to 5 times than that of original rock mass. But after grouting, distribution deviation of values (coefficient of permeability) had a great difference. It proves that the reduction effect of permeability just depends on the formation of rock joints and characteristic of arbitrary selective running.
(2) In design of lining concrete considering grout pressure, reasonable reduction factor is necessary to the analysis. Because existing design assumptions in practice about grout pressure on the back face of lining are conservative extensively. In this study, grout pressure of 2 at back face of lining was only a 10% of original injection pressure, 20.
(3) Prediction of lining loads in design process is a pre-requisite work to assess the initial values in numerical analysis and the results should be confirmed by field measurements. In this study, the increasement of lining loads due to grout injection was 21.25. Dimensionless factor, (Height of soil carried by lining / Diameter) was increased by 3 times during grouting comparing with before grouting.
(4) As a result of structural analysis of lining including with grout pressure, internal working stress of the lining concrete was less than the allowable compressive stress. It is recommended that analysis should be processed in various load combinations and optimized in reasonable ways, because the results are affected by the input values, which also vary from one method to another depending on the rock relaxation loads or water pressure increasement.
(5) More case study should be needed, especially about the estimation of lining loads, the application of reduction factor of grout pressure, and grout reinforcing range and its effects on tunnel lining.

목차 (Table of Contents)

• 제1장 서론 = 1
• 1.1 연구배경 = 1
• 1.2 연구목적 = 2
• 1.3 연구범위 및 내용 = 2
• 제2장 도수로 터널 개요 = 4
• 2.1 개요 = 4
• 2.2 시험구간 지질현황 = 4
• 2.3 보강현황 = 5
• 2.4 재료 특성치 = 6
• 제3장 암반하중 이론 = 10
• 3.1 개요 = 10
• 3.2 암반하중 산정법 = 10
• 3.2.1 Bierbaumer의 이론 = 12
• 3.2.2 Terzaghi의 이론 = 13
• 3.2.3 Terzaghi의 암반 하중 분류표 = 14
• 3.2.4 Unal and Venkateswarlu = 15
• 3.3 요약 = 16
• 제4장 현장시험과 계측 = 17
• 4.1 개요 = 17
• 4.2 터널 하중 계측 = 17
• 4.2.1 필요성 = 17
• 4.2.2 터널계측의 문제점 = 18
• 4.2.3 터널 하중 계측 방법 = 18
• 4.2.4 평가 = 20
• 4.3 시험 개론 = 21
• 4.3.1 시험 일정 = 21
• 4.3.2 주입 방법 = 22
• 4.3.3 압밀그라우팅공의 배역 = 23
• 4.3.4 종방향 압밀그라우팅 모식도 = 23
• 4.5 공내재하시험 및 수압시험 = 24
• 4.5.1 공내재하시험 = 24
• 4.5.2 투수시험(Lugeon Test) = 27
• 4.5.3 현장시험 요약 = 30
• 4.6 계측 = 31
• 4.6.1 계측 개요 = 31
• 4.6.2 계측기의 배치 = 31
• 4.6.3 변형율계(Strain Gauge) = 31
• 4.6.4 설치 = 34
• 4.7 계측결과 및 분석 = 37
• 4.7.1 무응력 스트레인 게이지 = 27
• 4.7.2 매입형 스트레인 게이지 = 39
• 4.7.3 부착형 스트레인 게이지 = 43
• 4.7.4 토압계 = 45
• 4.7.5 배면그라우팅 효과 분석 = 47
• 4.7.6 압밀그라우팅 효과 분석 = 47
• 4.8 요약 = 48
• 제5장 라이닝 하중 예측 및 평가 49
• 5.1 개요 = 49
• 5.2 라이닝의 개념적 이해 = 49
• 5.3 Combined Lining System의 라이닝 하중 산정 = 50
• 5.3.1 STeel Rib + Shotcrete Lining = 50
• 5.4 그라우팅이 라이닝 하중에 미치는 영향 평가 = 53
• 5.5 요약 = 54
• 제6장 Lining 구조해석 = 56
• 6.1 해석 개요 = 56
• 6.2 라이닝의 역할 = 56
• 6.3 해석 프로그램 (SAP2000) = 57
• 6.4 Modelling = 58
• 6.4.1 설계조건 = 58
• 6.4.2 라이닝 모델링 = 60
• 6.4.3 지반반력 계수 = 60
• 6.5 하중조합 = 63
• 6.5.1 설계 적용하중 = 63
• 6.5.2 하중조합 = 67
• 6.5.3 경계조건 = 68
• 6.6 해석 및 분석 = 69
• 6.6.1 분석 방법 = 69
• 6.6.2 해석 결과 = 70
• 6.7 요약 = 76
• 제7장 결론 = 78
• 참고문헌 = 80
• ABSTRACT =82
• 감사의 글 = 84