Ground Penetrating Radar

Infrastructure hidden risks/Subgrade defects/Ballast bed contamination detection system

GD Real Testing has been dedicating to the research in advanced ground penetrating radar technology applied in subgrade/ballast bed/tunnel Infrastructure of the ballasted track. This involves the development and promotion of comprehensive detection equipment and software packages. The "High speed Detection System for Heavy Haul Railway Subgrade/Ballast" independently developed by GD Real Testing is a vehicle mounted high-speed non-destructive detection system that based on the deep detection scene of China's heavy-haul railway and the maintenance decision-making requirements of China's national railway. Its detection targets are infrastructure hidden dangers/subgrade defects/ballast bed contamination of the ballasted track. It has been promoted and applied in the entire line of Shuohuang and Xinshuo heavy-haul railway of China National Energy Group. Nearly 30000 kilometers of testing mileage have been completed at the Shanghai Railway Bureau of China National Group Corporation, Providing a comprehensive data bank for the transition of track ballast maintenance operations from 'periodic repair' to 'condition-based repair', thereby saving a significant amount of rail track maintenance costs.

1. System Introduction

(1) system function

(2) Detection target

Subgrade defects: subgrade voids, settlement, fragmentation, water rich areas, etc;

Ballast bed contamination: ballast bed contaminants distribution, areas rich in water, slurry boiling, mud overflow, evaluation of large machine cleaning effectiveness, detection of ballast deficiency, etc;

(3) system composition

The system mainly consists of a radar host, ballast bed detection antenna, subgrade detection antenna, structural detection antenna, data acquisition industrial computer, data acquisition software, data processing software, and connecting cables.

2. Test case

The "High speed Detection System for Heavy haul Railway subgrade/ballast bed" adopts a high-power system design and customized development of high gain antennas, which can achieve deep detection of tunnel subgrade (4.5 meters), accurate evaluation of subgrade contamination, and has the ability to detect frozen soil.

(1) The comprehensive inspection of in the Shuohuang heavy-haul railway of China National Energy Group

(2) China Railway Shanghai Bureau Railway ballast bed contamination and subgrade defects detection

3. Results Display

(1) Tunnel subgrade inspection 

(2) Distribution of contamination on the subgrade

(3) Real time contamination curve output

(4) Excavation verification(Sand content in subgrade)

(5) Sand content in subgrade

4. Advantages

Through long-term cooperation with Shuohuang Company and the Shanghai Railway Bureau, a substantial experimental data bank has been established. Based on excavation verification, size calibration, and experiments on the dielectric constant of contaminated track beds, GD Real Testing Company has achieved significant results in the quantitative detection of track bed contamination and algorithm research on track bed contamination. These achievements can be summarized as follows:

1. A quantitative evaluation system based on radar detection of track bed fouling rates;

2. An assistance decision-making and screening quality evaluation system;

3. Customized development of integrated ground-penetrating radar detection equipment for heavy-haul railway track bed/subgrade/foundation structures;

4. The first implementation of "condition-based repair" guided by detection data for screening construction, leading to significant savings in staff costs.