Abstract

The shield TBM method can eliminate environmental hazards such as noise and vibration, and is environmentally friendly and allows safe tunnel construction even in soft ground conditions, but there are many restrictions on its application due to its high construction costs compared to the NATM. Therefore, in order to increase the appli- cability of the shield TBM method, it is necessary to ensure economic efficiency by reducing construction costs, and it is very important to reduce segment construction costs, which account for the largest proportion of shield TBM tunnel construction costs at about 35 to 40%. As part of this, this paper considers the changes in segment stress during tunnel construction and operation, tunnel external load conditions, etc. through analysis of long-term measurement data of shield TBMs in Japan, which has abundant experience in shield TBM construction, and compares and analyzes the differences between predicted values at the design stage and measured values during operation. Through this, we study improvements to ensure segment economic effici- ency at the shield TBM design stage.