Shintaro INOUE



Dittermine the Correction Alignment and the Layout of Segments by the Snake Motion Algorithm 



Mitsutaka SUGIMOTO

 

The shield machine is expected to excavate along the planned tunnel alignment. However, it is common to find the machine following a different path. In that case, to keep the deviation within standards, it is necessary to restore the machine to the planned tunnel alignment.
 The most traditional method to decrease the deviation is to adjust the jack patterns. It only provides a way to change the excavation direction. That's why it is only possible to adjust the position of the shield machine, but not the direction of the shield axis. Therefore, the machine deviates again even if the position is restored to the planned tunnel alignment. On the other hand, in the snake motion algorithm, correction alignment is proposed based on the geometric conditions, and the machine excavates along it to restore the position and direction. This algorithm enables more accurately construction than the traditional method.
 The layout of segments is to combine several types of segments according to planned tunnel alignment. Normally the layout is done before excavation. However, when the shield machine following a different path, the layout has to be changed. Since the traditional method has few constraint conditions, the combination of segments to be allocated becomes huge. Since it was calculated by experienced technicians by trial and error, much labor and time were required. However, if correction alignment is determined by the snake motion algorithm, a constraint condition is added. Therefore, the layout of the segments is considered to be easy. Establishing the segment layout algorithm based on the correction alignment can be expected to improve the efficiency of the work.
 In this research, we applied the snake motion algorithm and segment layout algorithm based on the correction alignment to the real construction site. As a result, the knowledge that they are geometrically valid was obtained.