随着我国沉管技术的发展，越来越多的水下隧道采用沉管法施工。而沉管隧道中，固定干坞以及移动干坞方案的选择与工程造价有着莫大的关联，以广州市生物岛—大学城隧道工程为例，对预制管节的场地选择（固定干坞及移动干坞）在经济上进行分析比较，并综合考虑隧址周边环境、施工条件、工期等因素，确定了该隧道采用固定干坞作为管段预制场。

Along with the development of the immersed tunnel technology, more and more underwater tunnels are constructed by immersed tube method in China. The selection between fixed dry dock option and movable dry dock option is closely related to the project cost. Taking ShengwudaoDaxuecheng tunnel as an example, the author makes economic analysis on the fixed drydock option and movable drydock option. Taking the surrounding environment, construction conditions and schedule of the project into consideration, the author finally concludes that fixed dry dock option should be adopted for the prefabrication of the tunnel elements.