To address the issue that high water content in newly constructed tunnels causes significant attenuation of ground penetrating radar(GPR)signals,rendering them unable to detect voiding areas,this study took the following steps:firstly,forward modeling experi-ments were conducted to simulate GPR signal responses under different water content condi-tions.Then validation experiments were set up in actual engineering scenarios to collect GPR data and analyze their characteristics.Special attention was paid to the influence of reinforce-ment bars(rebars)on the signal,and targeted solutions were proposed based on the experi-mental results.Finally,GPR data features under different aging conditions were compared to determine the optimal detection timing.The experimental results show that high water con-tent and the presence of rebars significantly affect the characteristics of GPR signals.Under low water content conditions,GPR data features are more pronounced,facilitating accurate detection of voiding defects.For newly constructed tunnels with plain concrete structures,it is recommended to conduct non-destructive tests at the age of 120 days,while for reinforced concrete structures,testing should be carried out after 180 days.This study delves into the response characteristics of GPR signals under different water content conditions and identi-fied the optimal detection timing and methods.Targeted solutions are proposed to address the interference caused by high water content and rebars,providing crucial technical support for non-destructive detection of voiding defects in tunnels.
NETL
NSTL
万方数据
