Ventilation Technology for High Altitude Long Distance Tunnel Construction(To be continued)

5. Construction ventilation effect

On November 27, 2009, the ventilation effect test was carried out for each tunnel opening, and the ventilation effect of each working face was good. Taking the No. 10 inclined shaft as an example, the construction area used 4 working faces to construct at the same time, and the air quality met the sanitation and safety of the plateau alpine tunnel construction. Environmental control standards, the measured results are shown in Table 5.

Table 5    No. 10 inclined shaft ventilation effect monitoring data table

Location Ventilation method and status Measuring point location On-site work status palm mileage Ventilation distance and the length of the

tunnel ventilation duct from the face (m)

Measurement item
O2 content(%) CO content(ppm) H2S content(ppm)
No. 10

Inclind shaft

Clapboard ventilation,

fan power 2x55kW

I line Xining direction face mucking and removing, ventilated DK307+384 1358/25 18.5 53 60
I line Golmud direction face Gunite, ventilated DK309+798 1940/25 19.0 3 0
Ⅱ line Xining direction face Palm stops working, ventilated DK307+350 1392/30 18.9 6 0
Ⅱ line Golmud direction face Palm stops working, ventilated DK309+809 1942/30 19.1 3 0

6. Conclusion

6.1 The Guanjiao Tunnel is currently the longest mountain tunnel under construction in China. It faces major technical difficulties in construction ventilation at high altitudes, long distances, and multiple working faces. The ventilation standards implemented in various countries in the world are generally between 3 and 8m3/(kW·min). According to the actual situation in my country, the implementation sanitation standards for the construction of high-altitude Guanjiao tunnels are proposed.

6.2 According to the various construction organization forms implemented in the Guanjiao Tunnel, through systematic theoretical research and field tests, the staged construction ventilation and the mixed ventilation of the inclined shaft clapboard roadway are proposed, which successfully solves the construction ventilation problem. The long tunnel construction has accumulated successful experience.

6.3 The four working faces of Line 1 and Line II are used for the construction of the inclined shaft in the construction of the positive tunnel at the same time. The test results show that the ventilation effect of each working face is good, and the air quality meets the ventilation standards.

                                        End


Post time: Jul-04-2022