长期以来针对隧道防水该采用全包防水方案还是半包防水方案,一直是人们争论的焦点。依托厦门翔安海底隧道,对不同防排水方式(即全封堵、堵排结合及排放方式)的隧道衬砌水压力分布规律采用相似模型试验的方法进行研究,模型试验的比例尺为1:38.88,试验台架可同时施加土压和水压。通过模型试验得出结论:全封堵条件下,防水板全包、半包对衬砌背后的水压力、结构的受力无明显影响;隧道内排水后,半包段衬砌背后水压力明显减小,并随着排水量的增加,水压力基本成直线下降,并且半包段衬砌应变较全包段小,半包情况下衬砌结构受力较为有利。
Arguments and focus have always been given to the evaluation of the fully and partially wrapped waterproof systems for tunnel linings. Based on Xiangan subsea tunnel project in Xiamen, similarity model tests are performed to explore the distribution of water pressures under various drainage conditions (fully undrained, partially drained and drained). The model test scale is 1:38.88. The water pressure and soil pressure are applicable at the mean time during the tests. The test results show that the fully and partially wrapped waterproof systems are similar under undrained condition, while the partially wrapped waterproof system can effectively reduce the water pressure against the tunnel linings, and it is more friendly to the structure under the drained condition. In addition, the area of the partially wrapped waterproof system is smaller than that of fully wrapped waterproof system. Therefore, the partially wrapped waterproof system is recommended.