TBMs: Capabilities, Limitations and Challenges Yun Bai 1(&) , Xi Jiang 1 , Diana Diaz 1 , Xuehui Zhang 1 , and ZhuanZhuan Zhang 2 1 Department of Geotechnical Engineering, Tongji University, Shanghai, China baiyun1958@tongji.edu.cn 2 China Tiesiju Civil Engineering Group Co., Ltd., Hefei, China Abstract. The Tunnel Boring Machine (TBM) technology has significant advantages over conventional Drill & Blast method, and it has become one of the most common tunnel excavation methods in the world. However, weak- nesses of TBM such as the poor adaptability to complex geological conditions create a bottleneck in its functionality, and restrict its further development. Therefore, factors such as engineering geological conditions, construction schedule, cost, environmental impact and other multi-disciplinary influences should be well considered in the TBM selection. This paper presents the capabilities, limitations and challenges of TBM method by a study of various case projects, and proposes effective countermeasures towards bad geological conditions. The results of this research are helpful for improving the TBM working ef ficiency and ensuring a smooth and safe construction. Keywords: Tunnel excavation Á TBM method Á Capacity Á Limitations Complex geology 1 Introduction In the 21st century, a new trend in development has emerged, which is called “sus- tainable development” and most policies and processes must follow up its goals and considerations. As a result, the underground space is again valuable as a space for human beings to survive on earth [1]. After more than two centuries of wide application of TBMs (Tunnel Boring Machines), and thanks to continuous scientific and techno- logical advances, such mechanized excavation technology is being extensively used around the world for tunnel construction in all kinds of infrastructure projects (like railway, highway, hydropower, etc.). Among its multiple functions, a TBM can excavate, support, install lining and remove muck synchronously. Moreover, with the extensive use of electronic infor- mation technology, such as real-time monitoring and distant control, full access to the construction process becomes possible, allowing it to reach a relatively optimized state. Until today, these were the key advantages of TBM technology. TBM’s construction speed is probably the biggest advantage, which is 4 to 10 times as high as the conventional Drill & Blast (D&B) method. In addition, TBM tunneling offers a lower life-time cost, saves much labor force, and is environmentally friendly. © Springer Nature Singapore Pte Ltd. 2018 D. Zhang and X. Huang (Eds.): GSIC 2018, Proceedings of GeoShanghai 2018 International Conference: Tunnelling and Underground Construction, pp. 528–535, 2018. https://doi.org/10.1007/978-981-13-0017-2_53