京雄城际铁路机场隧道DK46+092~DK53+300区间位于区域性地面沉降明显地段,为了更加迅速、直观地了解隧道在施工和后期运营过程中的安全情况,掌握隧道结构的健康状态,需要对其进行安全监测。基于光纤光栅感测原理,在京雄高铁的在建隧道中进行了隧道衬砌环向应变感测、隧道衬砌变形缝相对位移感测和隧道周边分层沉降监测;详细介绍了传感元件的布设安装工艺,实现了大断面隧道结构健康监测的自动化、远程化控制。初期监测结果显示了隧道在混凝土浇筑养护期以及回填期内断面上应变、轴力与弯矩的变化规律。光纤光栅自动化、长期监测的实时性和精确性有利于实现对隧道结构的实时监控和早期预警。

The DK46+092-DK53+300 sections of the Jingxiong intercity railway airport tunnel are located in the area with obvious land subsidence. In order to understand the safety situation of the tunnel during construction and later operation in a more rapid and intuitive way, it is necessary to monitor the health status of the tunnel structure. In this paper, based on the fiber grating sensing principle, the circumferential strain sensing of the tunnel, the relative displacement sensing of the deformation joint, and the layered settlement monitoring around the tunnel are carried out. The layout and installation processes of the sensor elements are introduced in detail, and the automatic and remote control of the health monitoring of the large-section tunnel structure is realized. The initial monitoring results show the changes of the strain, axial force, and bending moment of the tunnel during the concrete pouring and curing period and backfilling period. The automation and long-term monitoring of fiber Bragg grating are beneficial to the real-time monitoring and early warning of the tunnel structure.