NATM 터널 시공에 따른 상부 구조물 계측관리 적용사례 연구

Abstract

본 연구를 통하여 얻은 결과를 요약하면 다음과 같다. 1) OO교 및 OO강변대로에서의 NATM터널 시공에 따른 계측결과는 경사계 1/126 ∼ 1/175 (기준값: 1/101 ∼ 1/129), 침하계 2.041mm (기준값: 20mm), 천단변위4mm (기준값: 7.039mm), 내공변위 2mm (기준값: 2.729mm), 상판변형센서 +1.135 ∼ -2.880mm (기준값: +3.135 ∼ -4.880)로 현장관리기준을 충분히 만족하였다. 2) 대상 구조물의 수치해석결과 1 경간의 최소안전율이 1.77이며, 2 경간의 최소안전율은 1.50이고, 기둥모멘트의 최소 안전율은 1.24이고, 기둥축력의 최소 안전율이 1.22로서 설계관리기준을 충분히 만족하였다. 3) 향후 도심지 터널공사시 상시거동에 대한 분석을 통하여 주변시설물의 구조 형식별, 계측 항목별 적절한 현장관리기준의 수립이 필요하다.

A large number of subway constructions are being carried out or planned due to extremely high demand of transportation. And, most of city subway tunnels are being planned by NATM construction method. But, during tunnel construction with NATM construction method, surrounding facilities might be damaged by ground subsidence and vibration. Therefore, stability of surrounding upper facilities for NATM tunneling work should be confirmed and also measurement controls establishing complementary measures are required. This thesis is to study examples of applying measurement control standards in construction fields for assuring the stability of upper facilities when executing NATM tunnel construction. A new standard was established in this study by considering the result from measurements for 23 months from October 2004 to September 2006 in OO bridge and OO riverside road and measurement control standards being used generally for diagnosis of stability, and details of executing field controls according to this standard were arranged. And also, the new standard was set up as field measurement control standards and the range of the study such as stability of facilities was established through verification of facilities with movement of the ground and numerical interpretation from tunneling work and comparative analysis of measurement control standards in designing and measured data. As the result of measurements for NATM tunnel construction in OO bridge and OO riverside road, clinometer was 1/126 ∼ 1/175 (permissible level: 1/101 ∼ 1/129), settlement gauge was 2.041mm (permissible level: 20mm), crown displacement 4mm (permissible level: 7.039mm), convergence was 2mm (permissible level: 2.729mm) and slab deformation sensor was +1.135 ∼ -2.880mm (permissible level: +3.135 ∼ -4.880), all satisfying field control standards. As a result of numerical analysis for target facilities, minimum stability ratio of 1 distance between pillars was 1.77, minimum stability ratio of 2 distance between pillars was 1.50, minimum stability ratio of pillar moment was 1.24 and minimum stability ratio of axial force of pillar was 1.22, all satisfying standards of design and control. Establishment of appropriate field control standards per type of structure of surrounding facilities and per measurement item will be necessary through analysis of regular movement when executing tunneling work in downtown area in future.