Beijing Capital International Airport T3B-T2 APM Tunnel and Traffic Link Tunnel

The first time in the world that a shallow-buried large-span tunnel protected by pipe-roof has been built beneath and operating runway.

Beijing Capital International Airport’s annual throughput is over 100 million, ranking first in China and second in the world. Due to the planning constraints and construction conditions, the East Terminal Area (T3 terminal building) and the West Terminal Area (T1, T2 terminal buildings) are far apart and without convenient traffic links.

The demands of passenger turnover and vehicle turnover between the East and West Terminals are up to 1,000 passengers per hour and 165 vehicles per hour, respectively. To improve the transfer convenience and turnover efficiency of Beijing Capital International Airport, an APM tunnel and a traffic link tunnel were built in parallel between T3 Terminal Building and T2 Terminal Building, despite the problem of constructing a large double-span tunnel, 23m in width, under the world’s busiest airport runway in service.

During the construction period, the runway had to remain in normal use, and the upper limit of runway settlement caused by tunnel construction could be no more than 30mm.

An intelligent deviation correction system for mini pipe-roof jacking shield was developed and applied in this project. The construction accuracy of 230m long pipe-roof was: horizontal deviation of less than 15mm, vertical deviation of less than 10mm.

A remote automatic real-time monitoring technology was used for the operating runway settlement monitoring.

The grouting technique for runway settlement control in upper pipe-roofs was developed and used. During the construction, the maximum runway settlement was only 11.2 mm, and the runway remained in good condition throughout.