Abstract: Shield tunnel was adopted to underpass through WC taxiway section in the construction Taoyuan International Airport MRT project CU02A bid. Shield tunnels occur at least 20 residual anchors when they approached to faces. It will increase construction risk during shield tunneling. It is quite a special case for shield tunneling encountering the obstacle. Many methods for eliminating existed anchors, such as working shaft, face treatment by face stabilization by means of grouting or dewatering , shield tunneling directly and NATM tunnel, were evaluated except the cut and cover method. NATM tunnel is used to eliminate existed anchor. NATM tunnels and shield tunnels have been successfully completed in the underpassing the taxiway. The evaluation and development of the selection of the countermeasure is presented. In the end, the effectiveness of the adopted methods are studied in forms of the construction phase of NATM tunnel ,the monitoring results ,tunnel stability and settlement control.

Key words: shield tunnel, NATM tunnel, taxiway