Abstract:The plain concrete abutment body of an interchange in Nanchang has cracked diagonally. In 2010, the crack width was measured to be 1.5 mm. In 2011, the cleaning grouting reinforcement was adopted. By 2020, during the reinforcement construction, after the surface coating was chiseled off, it was found that the crack width had expanded to 5 to 6 cm. The sediment accumulated inside the crack, and top pavement locally cracked and sunk, which seriously affected the safety of bridge operation. The crack propagation disease is caused by the infiltration of silt and sand from the backfill behind the abutment, which makes it difficult to clean thoroughly, and the crack cannot be completely repaired by grouting. The support is aging, and the cracks continues to expand under the action of the beam temperature expansion and contraction, and the vehicles. The repeated painting of bridges has a covering effect on cracks, and the appearance inspection cannot truly reflect the width of cracks, resulting in failure to reinforce in a timely manner. Based on the traffic conditions, crack damage and causes, the temporary steel pipe is set up to support the girder in order to ensure the traffic on the bridge without interruption. RPE water-expansion anchor rods are used to anchor the concrete on both sides of the abutment crack. The cracks are washed clean, and filled and sealed with grout. To prevent cracks from cracking and expanding again, the steel bars are planted at the location of the crack on the abutment and a 1-m thick reinforced concrete wall is poured to connect the abutment as a whole, which improves the bearing capacity of abutment. The abutment has been operating well after reinforcement. The reinforcement scheme can provide reference and inspiration for similar projects.
