Based on the analysis of ambient environment and geologic conditions, technical scheme study was carried out for the river-crossing Dongjiang tunnel in terms of construction method, tunnel embedded depth, selection of shield type and segments. In the construction method, related factors such as navigation requirements of Dongjiang river, geological conditions, working site, time limit, etc. Were compared for selection; internal periphery of tunnel lining was determined through analysing clearance, requirements of aerodynamics and installation of pipe lines, considering the segment design factors; tunnel embedded depth was analysed and determined according to the safety of the buildings above the tuunel, geological parameters of the traversed ground, construction safety, anti-floating and anti-flood requirements of the tunnel. Necessary measures for securing construction safety are discussed in the end of the paper.%通过分析周边环境和地质状况,对下穿东江的隧道施工方法、隧道衬砌内轮廓、隧道埋深、管片及盾构机选型进行技术方案研究.其中隧道施工方法考虑了东江通航要求、地质状况、施工场地、工期等因素进行比选；隧道衬砌内轮廓拟定主要通过分析限界、空气动力学的要求、管线布置来确定,并对管片设计要素进行论述；隧道埋深则从隧道上方建筑物安全、下穿地层的地质参数、施工安全、隧道抗浮、防洪要求来分析确定；最后论述在施工过程中应采取保证施工安全的措施.
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