Scope of Work:	Void detection under the road using Ground Penetrating Radar technology for maintainance and repairing of these voids to restore cracked road surface
Location:	Dahej, Gujarat, India.
Client:	Anandjiwala Technical Consultancy
Equipment:	GSSI SIR-3000 equipped 400 MHz antenna
Challenges:	Differentiating void reflection and reflection form other objects was a big challenge
Summary:	The GPR investigation has been carried out at Dahej for void detection under the road surface to prevent the propagation of cracks on the surface. The project was done for China Steel corporation ltd at Dahej over an area of around 2652 over a road surface and 2040m2 over the shoulder of 5m width each. The objective of the survey was to map all the possible underground voids using GPR to prevent the crack propagation on the road surface hence preventing the road damage. Hence, a GPR survey has been conducted to scan the area and map the possible voids. Various locations have been marked using GPR for the probability of the existence of the air voids under the 13 m wide road surface with 5 m wide shoulder on each side of the road at Dahej. In this GPR survey, an area of around 4700m2 has been scanned in 3D mode to detect air voids beneath if any to prevent the propagation of those cracks on the road surface. Various locations with possible existence of air voids have been observed beneath the road surface. However, shoulders were observed to contain more crucial locations with voids beneath it. Moreover, the profile of the road has also been observed which provided satisfactory possible profile of the road surface. Hence, GPR has been efficiently applied for the void detection at Dahej site.