Auxiliary device for preventing viaduct from settling and construction method thereof

The invention relates to the field of urban bridges, and discloses an auxiliary device for preventing a viaduct from settling and a construction method thereof. The auxiliary device has the function of preventing the viaduct from settling, and comprises an auxiliary bearing platform and a lateral limiting supporting part, the auxiliary bearing platform is arranged on a pile foundation of the viaduct, the outer part of an original bearing platform of the viaduct is covered with the auxiliary bearing platform, and pier studs of the viaduct penetrate through the auxiliary bearing platform; the lateral limiting supporting part comprises a supporting base and a supporting frame, the supporting base is arranged on the ground and is located at the outer sides of the pier studs, a base-connecting end of the supporting frame is connected to the supporting base, and a beam-connecting end of the supporting frame is connected to the position in which a cover beam of the viaduct is connected to the pier studs. According to the auxiliary device for preventing the viaduct from settling and the construction method thereof, the outer part of the original bearing platform of the viaduct is covered with the auxiliary bearing platform, thus the lower ends of the pier studs are more stable, and the bridge can be prevented from settling; through the adoption of the lateral limiting supporting part, the bridge can be effectively prevented from laterally deviating, and thus uneven settlement of the bridge is stopped from further deteriorating.