NATM터널의 안정성 해석과 계측을 통한 변위에 관한 연구

Abstract

요 지

최근 도시 교통량의 증가에 따른 대안으로 친환경 교통수단인 도시철도의 건설이 활발히 이루어지고 있는 상황으로, 도심지 곳곳에서 터널공사가 시공 중에 있으며, 터널 설계시 수치해석적 방법을 이용하여 예측한 터널의 거동은 지하 지반의 토질 상태와 굴착 이후 응력이완 등으로 실제 시공 중의 거동과 일치하지 않은 경우가 일반적이다. 본 연구에서는 NATM터널 굴착시의 현장 계측치를 유한차분법에 의한 안정성 해석 자료와 비교 분석을 실시하였다. 이를 위해 4개소의 천단침하와 수평측선 내공변위를 측정, 분석하였으며, 수치해석기법을 적용한 최대 변위량 해석치와 편차를 대비한 결과, 최대 변위량은 천단침하와 내공변위 모두 3mm로, 해석치 대비 천단침하는 평균 1.66mm 크게 내공변위는 1.02mm 크게 분석 되었으며, 이는 굴착시의 발파진동과 이완된 지반의 응력전이 현상에 일부 기인한다고 판단된다. 또한 현장에서의 관리기준치 대비 안전 수준으로 관측된 것으로, 이는 지보패턴 등 보강설계가 적정하고, 유사 암종 분포구조에 기인한다고 사료된다. 현재 사용되는 계측관리 방식은 측량기를 이용한 2차원 방식으로 시간적, 공간적 제약이 많으나, 최근 활용되고 있는 단면측정기(Profilometer)의 일종인 Laser Scanner는 입체적 분석이 가능하고 수치자료를 전산화하여 관리함으로써 시공 중 또는 유지관리 중에 다양한 형태의 분석이 가능하다. 본 연구에서의 해석치는 초기 지반조사에 의한 예측치로, 실제 터널을 시공하면서 암반 및 보강재의 물성치를 구하고 이를 다시 입력자료로 하여 수치해석을 함으로써 시공 중의 변위량을 예측하고 이를 토대로 역학적 안정성을 검토하는 방법과 3차원 해석이 가능한 새로운 계측관리 기법은 좀 더 다양한 연구와 발전이 필요하다고 사료된다.

주요어 : NATM, 계측, 유한차분법, 안정성 해석, 변위| ABSTRACT

A Study on the Displacement of NATM Tunnel by Stability Analysis and Measurement.

Hong, Joon-Hee Master of Science in Civil Engineering Graduate School of Engineering Hanyang University Advisor : Associate Professor Park, Du-Hee

Alternative due to the recent increase in traffic, the city actively being made in the construction of eco-friendly urban rail transportation, the displacement predicted by using numerical methods in the design of the tunnel, is generally does not match the displacement of the actual construction stage due to the soil condition of the underground and stress relaxation after excavation. In this paper, stability analysis by the finite difference method, data and comparative analysis was carried out on-site measurements of the tunnel excavation. In order to perform this paper, the measurement of the tunnel section of the four places in the crown settle mesurement and convergence measurement, the initial value after approximately 4 months of data were analyzed, compared maximum displacement deviation analized value, applied numerical methods to all 3mm, 1.66mm larger than an average of crown settle measurement, 1.02mm larger than convergence measurement the analyzed, the blasting vibration and stress relaxation transfer phenomena should be attributed. In addition, on-site management of the standard to be observed as compared th the level of safety, which is a reasonable steel-rib reinforcement design patterns, and similar rock types is thought to be due to the distribution. Management methods that are currently used measurement using a two-dimensional manner temporal and spatial constraints, recently been used in the cross-section measuring (Profilometer), a kind of three-dimensional Laser Scanner and numerical data can be analyzed by a computerized management during construction or during maintenance of various types of analysis. The numerical value of this study is values predicted by the initial site investigation, the actual tunnel construction and reinforcement properties of rock while it seeks to re-enter the data by the numerical analysis to predict the displacement of construction based on this review of mechanical stability and a new three dimensional analysis simultaneously measuring a variety of management techniques more research and development should be needed.

Key words : NATM, Measurement, Finite difference method, Stability analysis, Displacement.; ABSTRACT

A Study on the Displacement of NATM Tunnel by Stability Analysis and Measurement.

Hong, Joon-Hee Master of Science in Civil Engineering Graduate School of Engineering Hanyang University Advisor : Associate Professor Park, Du-Hee

Alternative due to the recent increase in traffic, the city actively being made in the construction of eco-friendly urban rail transportation, the displacement predicted by using numerical methods in the design of the tunnel, is generally does not match the displacement of the actual construction stage due to the soil condition of the underground and stress relaxation after excavation. In this paper, stability analysis by the finite difference method, data and comparative analysis was carried out on-site measurements of the tunnel excavation. In order to perform this paper, the measurement of the tunnel section of the four places in the crown settle mesurement and convergence measurement, the initial value after approximately 4 months of data were analyzed, compared maximum displacement deviation analized value, applied numerical methods to all 3mm, 1.66mm larger than an average of crown settle measurement, 1.02mm larger than convergence measurement the analyzed, the blasting vibration and stress relaxation transfer phenomena should be attributed. In addition, on-site management of the standard to be observed as compared th the level of safety, which is a reasonable steel-rib reinforcement design patterns, and similar rock types is thought to be due to the distribution. Management methods that are currently used measurement using a two-dimensional manner temporal and spatial constraints, recently been used in the cross-section measuring (Profilometer), a kind of three-dimensional Laser Scanner and numerical data can be analyzed by a computerized management during construction or during maintenance of various types of analysis. The numerical value of this study is values predicted by the initial site investigation, the actual tunnel construction and reinforcement properties of rock while it seeks to re-enter the data by the numerical analysis to predict the displacement of construction based on this review of mechanical stability and a new three dimensional analysis simultaneously measuring a variety of management techniques more research and development should be needed.

Key words : NATM, Measurement, Finite difference method, Stability analysis, Displacement.