ABSTRACT
In recent years, various technologies have been incorporated into construction monitoring. These include technologies such as lasers, inclinometers, fiber optics, etc. However, these technologies have not yet been widely utilized in the automated instrumentation of infrastructure projects. This paper presents a case study using MEMS-based linear chain sensors, specifically ShapeArrays (SAA), for convergence displacement monitoring in a new section of tunnel in Line 2 of the São Paulo Metro, which is being constructed using the New Austrian tunnelling method (NATM). The automated use of these sensors allowed for assessing the tunnel’s stability in response to the jet-grouting (JG) columns executed adjacent to the monitored section. This approach ensured greater safety in the ongoing tunnel excavation work and optimized the execution parameters for the JG columns, which reinforced the soil for the arrival of the Tunnel Boring Machine (TBM). The near real-time remote readings were compared with conventional instrumentation data and were crucial for the success of this project phase.
