为提高城市内河沉管隧道建设质量，首先，对广州市中心城区已建及在建沉管隧道建设特点进行分析，概况总结出4个建设难点，包括： 1）两岸路网衔接受限，隧道平纵布置困难； 2）周边环境复杂、隧道建设景观要求和环境保护要求高； 3）珠江航道较窄、堤岸防洪要求高、隧道建设关联工程量大； 4）基岩埋藏浅、岩面起伏大，基槽开挖与基础设置难度大。其次，结合广州市洲头咀隧道、车陂南隧道、如意坊隧道和会展西隧道的建设实践，系统阐述沉管隧道共享融合环保建设创新理念，并对包括变截面管节技术、共享干坞技术、硬质地基模袋砂围堰技术、水下基槽爆破开挖环境振动控制技术和管节干坞内全断面浇筑技术在内的沉管隧道建造创新技术进行总结。最后，展望未来中心城区沉管隧道建设重点研究方向，包括：
沉管隧道与城市地下空间有机融合总体设计方案、管节移动干坞预制技术和无干坞浮态浇筑技术推广、城市敏感环境下岩层基槽环保高效开挖方法，以及管节新材料、新结构应用。
In order to improve construction quality of immersed
tunnel in urban river, the construction characteristics of the immersed tube
tunnel built and under construction in Guangzhou are studied, and four
construction characteristics are summarized as follows: (1) difficult tunnel
layout due to the limited connection between the road network on both sides;
(2) complex surrounding environment, high requirements for tunnel construction
landscape and environment protection; (3) the narrow Pearl River Channel, high
embankment flood control requirements and large associated engineering; (4) the
difficult foundation trench excavation and foundation setting owing to the
shallow burial bedrock and great rock surface undulation. Then，combined
with the construction practice of Zhoutouzui tunnel, Chebeinan tunnel, Ruyifang
tunnel, and Exhibition West tunnel in Guangzhou, the innovative concepts of
sharing, integration and environmental protection are systematically
elucidated, and the innovative technologies including the variable section
element, shared dry dock, mold bag sand cofferdam on hard foundation,
environmental vibration control of underwater foundation trench blasting
excavation, and full section pouring in dry dock are summarized. Finally, the
future research of immersed tunnel construction in central urban area is
prospected to focus on the aspects such as the overall design scheme integrating immersed tunnel and urban
underground space, the prefabrication technology in mobile dry dock, the
element floating pouring technology without dry dock, the environmental
protection and efficient excavation method for the rock foundation groove under
sensitive urban environment，and application of new
material and novel structure for pipes.
