Abstract: The construction methods for large-diameter vertical shafts of deep highway tunnels (700 m) in cold and high-altitude areas are hard to choose. Therefore, based on severe environmental requirements of Xinjiang, China, complex engineering geologies of the Tianshan, urgent need for ventilation in the "three-hole" combination of drilling and blasting method and TBM method, as well as various factors such as construction conditions, construction period, and cost control, a survey is conducted on various shaft excavation methods such as top-down boring method, raise-boring method, drilling method, and vertical tunneling machine method with different shaft depths in different industries globally. Then comprehensive comparison is conducted in terms of geological adaptability, construction period requirements, site conditions, technical maturity, safety, environmental protection, and cost. Based on the construction experience of the 2-2 vertical shaft project of the Tianshan Shengli tunnel, some conclusions are drawn as follows: (1) The top-down boring, raise-boring, and drilling methods are mature in coal mine projects, and corollary equipment is complete, whereas they are new in 700 m-deep vertical shafts with great difficulty. (2) Before construction of the shaft, the permeability coefficient, water inflow, rock lithology, strength, location and length of fracture zone should be investigated and rechecked in detail. (3) The drilling method will increase the cost and construction period when applying in hard rocks, which should be carefully selected. (4) The super-deep vertical shaft tunneling equipment and technology are still in the exploratory stage, the cost will be drastically increased due to long equipment manufacturing period, slurry pump replacement, deviation correction, grease leakage of cutterhead, and frequent cutter replacement.

Key words:

highway tunnel, shaft, top-down boring method, raise-boring method, drilling method, vertical tunneling machine method