ABSTRACT
Esme tunnel for the Izmir – Ankara high speed railway project is located in the rural parts of the city called Usak in the mid-west section of Turkey. A 13,77 m diameter Robbins Crossover TBM has been utilized for the construction of the single tube tunnel with a total length of approximately 3 km. The tunnel alignment is developed through two main lithologies which are gneiss and mudstone, respectively. Gneiss was observed right after TBM launch for a few hundred meters, while the dominant lithology was dry mudstone with considerable amount of fine particle. Regarding the hydrogeological aspect, the project area is quite dry and can be considered almost arid. The low water amount and high fine content of the ground make the excavation with the Crossover TBM difficult, thus making the ground conditioning a challenge for the project success. In addition to that, the lack of natural or municipal water resources was a relevant issue in terms of sustainable operation, considering the water requirements of large diameter TBM. To manage all the project aspects and improve the TBM performance, a set of laboratory tests has been conducted on the samples taken from the jobsite to determine the best possible solution for the ground conditioning with a minimum amount of water. A tailor-made product has been developed and tested on site to see the in-situ large scale effects of the developed foaming agent. As a result of the good collaboration with the team on the jobsite, after a few hundred meters, record breaking advance rates and average monthly advances have been recorded for the given diameter. In this paper, preliminary laboratory tests, on-site tests, and TBM performance along with the data extracted from the TBM data logger are analysed and presented.
