Optimization on energy saving ventilation of gallery-type combined construction shaft exhaust in extra long tunnel

In order to solve the problem of construction ventilation in extra-long tunnel under the context of drilling blasting method and trackless transportation, the construction shaft is used as an air inlet or outlet to better ventilation effect. Construction shaft, used as an air inlet or outlet for better ventilation effect, is applied into the construction ventilation of extra-long tunnel under drilling blasting method and trackless transportation. Numerical simulation and field measurement being taken into consideration, Shaft effect has been profoundly analyzed on this study based on construction ventilation of Guantian tunnel, the optimization of fan arrangement near cross passage and the bottom of shaft. The result shows that it is reasonable to install the fan at the point which is 5m away from the axis between the shaft and exhausting connection passage. The best area to layout the jet fan is under the direction of airflow, which is close to the cross passage. And it is necessary that it should not be too far away from the cross passage and better to be installed in high places as possible is more reasonable. (c) 2017 The Authors. Published by Elsevier Ltd.