沉管隧道基础灌砂的实时无损检测试验研究

Experimental Research on Real Time Nondestructive Detection for the Filling Sand Foundation of Immersed Tunnel

灌砂法已成为沉管隧道基础处理的主要施工方法,在灌砂过程中实施监测并对灌砂效果进行评价对确保基础灌砂施工质量显得尤为必要。本文依托南昌红谷隧道工程等比例基础灌砂模型试验,采用冲击映像法和全波场法相结合的无损检测方法,对灌砂前、灌砂后以及灌砂过程中砂积盘的扩散状况进行了监测。通过在不同灌砂工况下波形、时频以及成像剖面的分析,比较平均冲击响应强度的变化,建立起沉管隧道基础灌砂施工的实时无损检测方法。通过定义充盈率指标,实现对灌砂施工效果的定量评价。本试验研究成果将为实际沉管隧道基础灌砂施工的监测提供依据与技术支撑。

The filling sand method has become the main construction method of foundation treatment for immersed tunnel. It is particularly necessary that the implementation of monitoring in the filling sand process and the evaluation of filling sand effect will ensure foundation construction quality. Based on the same-scale filling sand model test of Nanchang Honggu Tunnel,the diffusion state of sand deposit is monitored before filling sand,after filling sand and in filling sand process using non-destructive detection method combining impact image method and full wave field method in this paper. The waveform,frequency and imaging section are analysed and compared with an average impact response intensity changes under different filling sand conditions. The real-time non-destructive detection method for foundation construction of immersed tunnel is established. By defining the filling rate index, the quantitative evaluation of filling sand construction effect is realized. The results of this study will provide the basis and technical support for monitoring the actual filling sand construction of immersed tunnel foundation.