Bridge strengthening
Bonded steel plate technology
Reinforcement of reinforced concrete beams with steel plates is one of the basic methods for bridge reinforcement.
Engineering survey
In 1969, the design standard of Renminchang Bridge in Haikou City was steam-13, towing-60, crowd load 250kg/m2, full bridge width 11.5m, double lane, net 7m, span combination 5x 16.76m simply supported beam, full length 83.8m. In 1986, the width of the bridge was 22.06 M. The crowd load was 450kg/m2. The cross-section of the structure is shown in Fig. 1 and Fig. 2. Superstructure: original design cast-in-situ I-beam, slightly bent plate. After enlargement, two cast-in-situ T beams are added on both sides of the bridge deck. Bored pile foundation is adopted on the foundation.
Present situation:
In recent years, due to the low original design standards, vehicle loads have increased, bridges have been overloaded, and the main part of the bridge has shown signs of damage.
1) cracks on the lower edge of the main girder of the main bridge.
2) Some of the T-beams built in 1986 failed to meet the design requirements, vertical cracks appeared on the sunny side of the beams, local damage occurred at the end of the beams, and a small number of supporting pads cracked and damaged.
3) The imperfection of the expansion joint restricts the expansion deformation of the bridge deck, and the expansion joint damages and leaks, resulting in the water accumulation of the pier cap beam, the upper edge of the cap beam bearing parts are widespread concrete burst, the stress of the main steel corrosion;
4) the side T beam is partially damaged by ship collision.
5) there are partial bridging cracks in the microplate.
6) the pier beam is cracked and the steel bar is corroded.
Main reinforcement technology and materials
Steel plate sticking technology
Used: HM-120 steel plate bonding adhesive