Abstract: Luoxi stationNanzhou station shield tunneling section on the extended section of No. 2 and No. 8 line of Guangzhou Metro passes through the pile group of Caihong Garden. Many piles intrude into the clearance of the shieldbored tunnel, therefore Caihong Garden should be reinforced. Furthermore, the operation space for the reinforcement is small. Micro steel pipe piles with 350 mm diameter are adopted to underpin the pile foundation. When the shield arrives at the position of the existing piles, the piles are cut and reinforcement is made. During the reinforcement, the settlement of the buildings is stable and expected reinforcement effect is achieved.

Key words: Metro, shieldbored tunnel, largediameter micro steel pipe pile, underpinning, reinforcement