Statistical and Numerical Study of Chipping and Cracking in Segmental Lining


  • Mohammad Mohtadinia

    Department of Mining Engineering, Faculty of Engineering, University of Tehran, 16th Azar St, Enghelab Sq, 1417466191 Tehran, Iran

  • Mohammad Hossein Ahmadi

    Department of Mining and Metallurgical Engineering, Amirkabir University of Technology, 424 Hafez Ave, 1591634311 Tehran, Iran

  • Milad Manafi Fasaghandis

    Department of Mining Engineering, Faculty of Engineering, Sahand University of Thechnology, Sahand New Town, 51335/1996 Tabriz, Iran

  • Behnaz Hallaji Dibavar

    Department of Mining Engineering: Rock mechanics, Faculty of Engineering, Hacettepe University, 06800 Beytepe, Ankara, Turkey

  • Seyed Morteza Davarpanah

    Department of Engineering Geology and Geotechnics, Budapest University of Technology and Economics, H-1111 Budapest, Műegyetem rkp. 3., Hungary


Some of the most frequent damages of concrete segments in shield tunnels are chipping and cracking, which are followed by degradation of lining system. In this paper, these types of damages are studied in four subway and two water conveyance tunnels. More than 2100 concrete rings are examined for chipping inspection and another 3000 for determination of the cracking. Statistical analysis of the research data showed that corners of the key and counter-key segments carry the highest number of chipping, while most of the cracking occur in the middle zones and shape of the segments and number of trust jacks affect the cracking pattern. Two kinds of numerical models are used to examine the underlying damages, which are based on geometrical characteristics of tunnel lining and boring machine besides operational mistakes. Findings of the numerical simulation revealed that installation of segmental lining with the least amount of erection tolerances results in low amount of chipping, this is while using key-segments with 12–17 degrees of insertion angle reduces total magnitude of damage due to tensile and compressive stresses. Furthermore, the deviation angle of TBM’s jack and segment’s axis should never be more than 5 degrees; otherwise even high-quality concrete segments wouldn’t remain undamaged. Employment of boring machines with articulated system is proposed in this case.


segmental lining, statistical analysis, numerical modeling, key-segments, damage

Published Online


How to Cite

Mohtadinia, M., Ahmadi, M. H., Fasaghandis, M. M., Dibavar, B. H., Davarpanah, S. M. “Statistical and Numerical Study of Chipping and Cracking in Segmental Lining”, Periodica Polytechnica Civil Engineering, 64(3), pp. 869–886, 2020.



Research Article