Significance of GPR Studies in Urban Planning and Road Works—A Case Study from Gujarat, India

In this study, ground penetrating radar (GPR) survey has been carried out at proposed underpass location of Vaishnodevi Circle, Ahmedabad, Gujarat, India. The aim of the study is to map all the possible underground utilities (up to 8 m depth) including cables, water pipelines, gas lines and sewerage to prevent any potential damage to the same during future constructions. The main focus of the study is to exactly map the alignment of two water pipelines found at depth of 5.5 m from the natural ground level during piling works. Considering site requirements and expected depth of utilities, the area has been surveyed using 100, 200 and 400 MHz central frequency antennas mounted on SIR 3000 and SIR 4000 GPR systems to cover the depth upto 8 m with fair resolution. The data has been collected both in longitudinal and transverse directions and at night to have least disruption to traffic flow and ensure safety of people at site. The data has been properly processed and efficiently interpreted on the basis of observed features in the data, surface features and inputs from the local public and site engineers. A total of 26 utilities along the road and a number of utilities across the road stretch were found running beneath the ground at different depths and with different alignments. This study helps in minimizing the risks in the future construction phases and also helps in planning the excavation and drilling works after GPR survey results to arrive at best possible location and alignment of piles.