This new archeological find was really sensationalized in the press. Most articles implied, without explicitly stating, that the gates were huge in order to accommodate giants like Goliath.
But here is the sober actual announcement.
Prof. Maeir, of the Martin (Szusz) Department of Land of Israel Studies and Archaeology, said that the city gate is among the largest ever found in Israel and is evidence of the status and influence of the city of Gath during this period. In addition to the monumental gate, an impressive fortification wall was discovered, as well as various building in its vicinity, such as a temple and an iron production facility. These features, and the city itself were destroyed by Hazael King of Aram Damascus, who besieged and destroyed the site at around 830 BCE.
The Daily Mail, which sensationalized everything, does have good pictures and a video flyover of the site.