Numerical investigation into the effect of stepping on the circumferential joint in the precast tunnel segments under TBM thrust jacks


Karimi M., Chakeri H., Namin F. S. , Sharghi M., ÖZÇELİK Y.

ARABIAN JOURNAL OF GEOSCIENCES, cilt.13, sa.15, 2020 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 13 Konu: 15
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1007/s12517-020-05740-w
  • Dergi Adı: ARABIAN JOURNAL OF GEOSCIENCES

Özet

The mechanized tunnelling process is mainly coupled with precast concrete segments, which include segmental rings that they are placed in their place simultaneously with the boring operation. Segments are mainly loaded by thrust jacks during the installation stage. It is essential to limit the cracks and damages of the segments during this stage to be sure of their structural integrity and sustainability. Stepping on the circumferential joint is a problem that can occur during the ring assembly. The main purpose of this study is to investigate the effect of the stepping under the load caused by thrust jacks. For this aim, the occurred stepping has been analyzed in the Tabriz metro line 2 project. In this research, the stepping has been investigated in four states, including non-stepping state, 1-cm stepping state, 2-cm stepping state, and 3-cm stepping state. Each state also has four positions, which include stepping on the right side of the ring, on the left side, on the floor, and on the roof. According to the results of the numerical modeling, increasing the amount of the stepping increases the damages. These damages have reached their highest level when the segment has stepping at the roof position.