结合南昌红谷沉管隧道干坞坞底施工，对干坞坞底处理重难点进行分析，通过采取坞底合理优化分区促成管段预制流水化施工、基底软层分区换填、预制基座格梗枕梁采用角钢超平、起浮层采用“混凝土+滤水导流槽”、合理优化排水系统等技术措施，顺利完成干坞坞底施工，满足了管段荷载、快速预制和起浮等各方面要求。

The difficulties in the construction of the bottom of the dry dock of Honggu tunnel in Nanchang are presented. Countermeasures, including proper zone division of the dry dock bottom, zonal replacement filling, adopting angle steel for the sleeper beam, floating layers consisting of concrete and filtering channels and proper optimization of the drainage system, are adopted. In the end, the construction of the bottom of the dry dock has been completed successfully and relevant requirements have been complied with. 