FFU在盾构施工中的应用

随着盾构施工技术的不断发展和完善，越来越多的地铁区间隧道采用了盾构法施工。对于盾构始发和到达端头地层通常要进行加固处理，并且需要事先机械或人工破除围护结构；但若采用其他材料代替盾构穿越范围围护结构，盾构机则可直接切削该种材料，且地层加固范围可大大缩小。结合广州地铁五号线大坦沙南-中山八站区间盾构始发井设计，探讨SEW工法以及FFU在盾构始发施工中的应用。

Application of Fiber-reinforced Foamed Urethane (FFU) in Shield Tunneling

 Due to the development and improvement of the shield tunneling technology, more and more Metro tunnels are constructed by shield tunneling method, which in most cases calls for the consolidation of the launching and arrival shafts. In cases where the launching and arrival shafts are consolidated by traditional methods, the retaining structures of the launching and arrival shafts should be dismantled by machinery in advance. If some new materials, such as Fiber reinforced Foamed Urethanes (FFU), are used to replace the traditional retaining structures within the cross section of the shield bored tunnels, however, the retaining materials can be cut directly by shield machines and the ground consolidation scope can be greatly reduced. On basis of the design of the launching shaft of South Datanshan～Zhongshan Eight Road shield bored tunnel on line 5 of Guangzhou Metro, the authors present the application of Shield Earth retaining Wall system (SEW) construction method and FFU in shield launching construction.