All the palaces and palaces have been grounded. What does it mean? Which word echoes the following text?

Refers to Qin Shihuang's vigorous construction of Epang Palace in Qin Dynasty, which consumed a lot of manpower, material resources and financial resources. When Epang Palace was built, Qin Shihuang had no way to govern the country. Later, Liu Bang and Xiang Yu broke Qin. After entering the customs, Xiang Yu set fire to Epang Palace, and the prosperous and luxurious Epang Palace instantly turned into scorched earth.