大型内河沉管隧道基础灌砂模型试验及效果检测技术研究

Model Test and Effect Monitoring Technologies for Gravel Filling of Foundation of Large-scale Inland Immersed Tunnel

对某大型内河沉管隧道基础灌砂足尺模型试验进行详细阐述,应用冲击映像法、全波场无损检测法相结合的方式对试验模型中不同工况下灌砂前、灌砂过程中以及灌砂后的效果进行测试,对模型试验中不同工况下各项测试数据及结果进行系统分析,对沉管隧道基础灌砂工艺与灌砂效果进行评价。此外,介绍该大型内河沉管隧道基础灌砂效果现场监测内容及具体实施方法,基于先期施工各管段基础灌砂现场监测、潜水探摸及管段后续沉降监测结果,对大型内河沉管隧道基础灌砂效果现场检测及处理技术进行系统的研究。主要研究结论如下:1)冲击映像法可以监测砂积盘的生成及发展过程,可以较准确地判断灌砂填充状况和快速检测混凝土底板下部灌砂填充状态,是沉管隧道基础灌砂效果评价的有力手段,是动态把握灌砂过程、实时追踪施工过程的砂液变化的有力手段。2)已施工管段现场沉降量观测结果显示,沉管隧道E1—E6各管段已灌砂基础的承载力均满足设计要求,证明冲击映像法可以作为沉管隧道基础灌砂检测评定方法。

The model test of gravel filling of a large-scale inland river immersed tunnel is introduced in detail. The gravel filling effects of the model before gravel filling, during gravel filling and after gravel filling are evaluated under different construction conditions by impact imaging method and full wave field nondestructive detection method. The results of model test are analyzed. The gravel filling technologies and gravel filling effect of immersed tunnel foundation are evaluated. The site monitoring items and technologies of gravel filling of foundation of the large-scale inland immersed tunnel are introduced. The gravel filling effect of foundation of the large-scale inland immersed tunnel is analyzed based on site monitoring results of gravel filling, underwater detection and segment settlement. Some conclusions are drawn as follows： 1 ） The formation and development of gravel accretion disk can be detected by impact imaging method. 2） The segment settlement monitoring results show that the gravel filling effects of foundations from segment E1 to segment E6 are good.