The number of bridges in operation has increased. Along with the increase in the length of time bridges are in service, the structural safety of the bridges also decreases. Bridge substructure is a key component of bridges, but there are few studies on safety management and identification of water bridge substructure damage. Deep learning is a focus of research in the field of target detection, and this document lightens YOLO-v4 to achieve precise and intelligent determination of concrete cracks. This was combined with a point cloud algorithm to provide a three-dimensional estimate of faulty lesions. Finally, the BIM was combined with the method of identifying the underwater structure of the deck. Based on Revit, an integrated management system for underwater bridge structures is put in place. Performing detailed bridge damage management includes (1) 3D visualization of the bridge detail model view, (2) establishment of a bridge damage database, (3) bridge damage management, and (4) management of the comprehensive underwater bridge inspection cycle.

The problem of the underwater structure disease of the bridge is increasingly obvious, which has seriously affected the safe operation of the bridge structure, so it is necessary to detect the underwater structure regularly. There are many kinds of bridge underwater structure diseases. This paper targets the bridge underwater structural crack diseases adopts multiple image recognition networks for verification, compares the advantages of different networks, and takes the YOLO-v4 network as the main body to build a lightweight convolutional neural network.Mobilenetv3 replaced CSPDarkent as the backbone feature extraction network, while the feature layer scale of Mobilenetv3 was modified, and the extracted preliminary feature layer was input into the enhanced feature extraction network for feature fusion. The PANet networks are replaced by the depthwise separable convolution. Using ablation experiments to compare the performance of four algorithm combinations in lightweight networks. At the same time, the disease identification accuracy of each network and the performance of the network are tested in various experimental environments, and the feasibility of the lightweight network is verified in the application of bridge underwater structure damage identification.