1. Set steel dowel at the lower part of the beam first, and then pour it at the lower part of the beam to reinforce the original concrete.

2. Secondly, a bridge is built on the steel dowel at the lower part of the beam, so that the steel dowel at the lower part of the beam can be poured together with the lower beam.

3. Finally, check whether the bridge is covered with concrete. If not, the bridge can be reinforced again and then poured.