Subsoil Recognition for Road Investment Supported by the Integration of Geodetic and GPR Data in the Form of a Point Cloud

Abstract

During road construction investments, the key issue affecting the structure’s safety is accurate subsoil recognition. Identifying subsoil variability zones or natural voids can be performed using geophysical methods, and ground-penetrating radar (GPR) is recommended for this task as it identifies the location and spatial range karst formations. This paper describes the methodology of acquisition and processing of GPR data for ground recognition for road investment. Additional subsoil research was performed after karst phenomena were identified in the investment area, formations not revealed by geological recognition from earlier studies during the pre-design stage. Mala Ramac CU II radar with a 250 MHz antenna and a Leica DS2000 with 250 and 700 MHz antennas with real-time geopositioning were used to obtain the data. Regarding GPR data postprocessing, we present a method of converting spatial visualization into a point cloud that allows for GPR and geodetic data integration and confrontation. This approach enabled us to determine the locations of control trenches, the results of which were used for material validation, which is necessary to improve the reliability of subsoil recognition. The results showed a high correlation between the recorded GPR signals and the subsoil structure. Additionally, differences in the quality of results for measurements conducted before laying supporting layers with slag and on the completed road structure surface are illustrated.

Accuracy Tests and Precision Assessment of Localizing Underground Utilities Using GPR Detection

“…However, when choosing the technology reinforcing the tracking accuracy, one should consider the movement of the GPR (its speed may reach up to 10 km/h or even faster). It results in significant challenges for positioning, mainly due to the problems with obtaining "fix" solutions, i.e., capturing the total number of GNSS-wave phase cycles [29]. Similarly, when a georadar with an integrated GNSS receiver moves to the obscured areas, the visibility of available satellites will also be lost.…”

“…To ensure high accuracy and reliability of the location of the detected utility networks, the work of georadars is supported by other instruments: mainly surveying, such as GNSS satellite receivers, which work in real-time and use differential adjustments [28] so that they offer the accuracy of 3D positioning ranging from one to several centimetres (usually 1 to 5 cm), as well as robotic electronic total stations [29]. The latter enables to conduct precise positioning works on a level lower than one centimetre [8].…”

Building Information Modeling Uses and Complementary Technologies in Road Projects: A Systematic Review

“…When combined with drones (T 4 ), laser scanning (T 3 ) can provide topographic data from aerial perspectives, which improves the accuracy of the BIM model. Ground-penetrating radar (T 24 ) complements laser scanning (T 3 ) by detecting subway features that are vital for comprehensive road infrastructure planning [127]. 3D printing (T 20 ) leverages the detailed data provided by laser scanning (T 3 ) to create physical scale models and components for physical simulations and design validations, which facilitates a more iterative and accurate design and construction process.…”

Special Issue “Ground Penetrating Radar (GPR) Applications in Civil Infrastructure Systems”

“…Two different types of multichannel GPR were employed to study the depth and detection performance of abnormal objects. The remaining three papers [8][9][10] cover various topics and are classified as technical notes in this Special Issue.…”