沉管隧道底钢板空鼓的原因及对策

以广州生物岛—大学城沉管隧道工程为例，分析底板采用底钢板为外包防水的沉管管段在施工中出现钢板与结构混凝土局部脱空形成空鼓的原因及对结构产生的危害，并结合施工工艺优化阐述如何防止空鼓产生及出现空鼓后的后期治理措施。通过加强过程控制和必要的后期补救措施，有效改善底钢板空鼓这一施工缺陷的产生，降低渗漏水隐患，保证管段预制质量。

Causes and Countermeasures for Hollowing of Steel Bottom Plates of Immersed Tubes

The causes for the hollowing between the steel bottom plates and the structural concrete of the immersed tubes of the immersed tunnel from Shengwudao to University Town in Guangzhou are studied, the adverse impacts of the hollowing on the tunnel structure are analyzed, the countermeasures to prevent the hollowing and the treatment measures for the hollowing are presented. It is concluded that the defect of the hollowing of the steel bottom plates can be effectively controlled, the water leakage of the tunnel can be minimized and the quality of the prefabricated immersed tubes can be guaranteed, provided that the prefabrication process of the immersed tubes are strictly controlled and necessary repairing measures are taken.