大直径微型钢管桩桩基托换技术在地铁施工中的应用

广州地铁二、八号线延长线洛溪站—南洲站盾构区间从彩虹花园密集桩群中通过,大量桩基侵入盾构掘进区域,需对彩虹花园进行加固处理,但加固施工空间狭小。为了解决彩虹花园加固处理难题,采用350 mm大直径微型钢管桩进行桩基托换,盾构到达原桩位置时采取停机截桩方案进行加固处理。加固过程中建筑物沉降稳定,未出现任何裂缝,结构完好,达到预期加固效果,可供相似工程进行参考。

Application of Large-diameter Micro Steel Pipe Pile Underpinning Technology in Construction of Metro Works

Luoxi stationNanzhou 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 settle ment of the buildings is stable and expected reinforcement effect is achieved.