Back to Luocang was built in the early years of the Sui Dynasty. "Suishu·Shihuozhi" states: "Emperor Yang ascended the throne... the eastern capital was established, with Shangshu Ling Yang Su as the general supervisor, and two million people were recruited every month. The people from Luozhou Guonei and the world There are tens of thousands of wealthy businessmen in the prefecture. The new houses are in Xingluo and Luocang." According to reports, Cangcheng "returns ten miles a week and wears three hundred pits" to store grain and supply the eastern capital of Luoyang. After excavation and identification of the soil quality, it is found that the construction sequence of the warehouse is approximately as follows: first dig an outer diameter of 16 or 7 meters, an inner diameter of 10 to 12 meters, a width of 3 meters, and a depth of 1.5 meters. To the 2m annular base tank, then the base tank is rammed to form a solid silo opening. Then dig a cylinder-shaped silo with a depth of about 10 meters and a mouth slightly larger than the bottom in the mouth of the rammed silo. The outer base trough is like a "protective cover" to make the inner cellar stronger.

According to existing data, a warehouse with an inner diameter of about 10 meters and a depth of about 10 meters should store about 500,000 kilograms of grain. In order to keep the warehouse dry, craftsmen first use fire to grill the entire warehouse during construction. Then apply a layer of green plaster on the wall surface, then pave a layer of wooden boards with wooden nails, and finally put a layer of mats on the wooden boards before storing the grain. (For reprinting, please indicate see Tao.com www.seetao.com) Seetao.com editor/Xia Changwang