城际铁路隧道下穿机场滑行道方案探讨

珠三角城际铁路新塘经白云机场至广州北工程花机间隧道下穿广州白云国际机场T3、T4及特种车滑行道。针对穿越工程地层上软下硬、岩溶发育的特点,在不停航的情况下,对盾构法及矿山法穿越方案进行探讨。设计通过超前预注浆加固、高压水平旋喷桩超前支护、长管棚超前支护等措施保证穿越工程的安全。经数值分析,各项指标满足机场方面要求,明确采用矿山法下穿滑行道的可行性,同时建议对先行隧道施工过程中的最大沉降控制值按最终控制标准的80%~90%进行控制。岩溶按"开挖前探明、开挖中发现"进行分类处理。

Discussion on the Scheme of Intercity Railway Tunnel Passing under Airport Taxiway

The tunnel of Guangdong Pearl River Delta Intercity Railway( Xintang-Baiyun Airport-Guangzhou North Railway Station project) passes under T3 / T4 and special vehicles taxiway of Guangzhou Baiyun International Airport. Based on the geologic conditions with complex strata and highly developed karst,this paper discusses the feasibility of using shield driving method and mining method to excavate the tunnel passing under the airport taxiway. In the design process,such auxiliary measures as long pipe roof,horizontal jet grouting pile and grouting reinforcement are selected to ensure the safety of engineering. The numerical computation analysis proves the compliance of all indexes with the requirements for airport operations and the feasibility of mining method tunnel to pass under airport taxiway,also recommends that the maximum subsidence control value in the process of the first tunnel excavation should be 80 to 90 percent of the final control standard. The karst cave is treated accordingly based on "investigation before excavation and identification during excavation".