Abstract: A reinforcement structure includes multiple steel bars, a primary spiral hoop enclosing the multiple steel bars, wherein joints of the primary spiral hoop and the steel bars are securely combined, multiple secondary spiral hoops, wherein multiple steel bars are inserted into each of the secondary spiral hoops from outside of the primary spiral hoop to inside of the secondary spiral hoop so that joints between the primary spiral hoop and the secondary spiral hoop are formed. A steel bar is sandwiched between the primary spiral hoop and the secondary spiral hoops and joints of the steel bar to the primary spiral hoop and the secondary spiral hoops are securely combined via steel wires. The reinforcement is thus formed by the steel bars, the primary spiral hoop and the secondary spiral hoops.