中文摘要：

为了给出厦门翔安隧道洞口段管棚超前支护的设计参数，采用快速拉格朗日有限差分法分析了管棚超前支护的效果；指出施工中遇到的问题及解决办法．洞口浅埋段采用40m长管棚超前支护，经注浆形成的加固圈起到了“承载拱”的作用，有效控制了地面不匀匀沉降．管棚施工中克服了钻孔循环介质对地层的扰动，为安全进洞发挥了作用．

英文摘要：

The design parameters of shed-pipes of Xiamen Xiang＇ an sub-sea tunnel portal are presented and then the impacts and effects of shed-pipes are analyzed by FLAC （Fast Lagrangian Analysis of Continua）. The key technologies of shed-pipe construction are summarized, and the problems and solutions in the con- struction process are mentioned. The 40 m long shed-pipes combined with grouting can act as “carrying arch”, which makes the distributing of ground subsidence uniform and can control the maximum settlement effectively. The problems of stratum disturbance, which caused by cyclic medium of boreholes, are overcome. The shed-pipes play important roles in tunneling in terms of safety.