# Using AI-Based Tools to Quantify the Technical Condition of Bridge Structural Components
## 1 Introduction  
Bridges have accompanied humanity throughout history, connecting cities, regions, and countries, ensuring the mobility of people and transport, thereby contributing to economic development. The first bridge structures had a fairly simple structure and were made of available natural materials such as wood, plant fibers, animal skin, and stone. Modern bridge structures are complex and differ in technical solutions, dimensions, materials used, mass, and other characteristics. The technical condition of bridges is determined by the level of their functional consumer properties: load-bearing capacity, throughput, traffic safety, fire and environmental safety, protection from extreme natural and man-made impacts, and durability [1; 2]. At the same time, different types of damage affect specific consumer properties: force damage--on load-bearing capacity, corrosion damage--on durability, and damage to the bridge deck--on throughput and traffic safety [3]. During use, bridges are subjected to various loads, which leads to the development of defects and, ultimately, to the loss of the structure's bearing capacity. Various methods are used to assess the technical condition of structures to prevent such situations. This concept refers to a set of individual characteristics and criteria that allow determining the deviations of local or integral parameters characterizing the operation of the structure from some initial values, for example, the type and size of defects, stresses, deformations, deflection values, vibration frequencies, etc. Ensuring reliable and trouble-free operation of bridges, which are an integral part of the transport infrastructure, becomes more and more urgent every year due to several reasons [4]:  
* A significant increase in traffic intensity on highways;
* A change in the composition of vehicles in the direction of increasing load;
* An increase in traffic speed;
* An increase in the level of environmental aggressiveness. Currently, there is no single methodology that would allow us to obtain all the necessary information about the technical condition of bridge structures. However, the generally accepted stages of diagnostics are their periodic inspection and testing [5]. Inspection is the process of obtaining qualitative and quantitative indicators of the operational properties of an object, determining and assessing its technical condition, and providing recommendations for maintaining its operational suitability or terminating its operation [6]. When conducting inspections, initial information about the condition of structures is obtained, which allows for the specification of further areas of research. Inspection methods include visual inspection of a structure and flaw detection--ultrasonic, magnetic, and others--aimed at detecting several types of damage. Based on the data obtained, calculations are made of changes in the strength characteristics of structural elements, load-bearing capacity, assessment of material wear, and other parameters that affect the safety and durability of the structure. Timely inspection allows us to collect data on the bridge's condition, which is critically important for making decisions about its operation. Practice shows that inspection costs pay off due to the optimization of bridge operation and maintenance costs. Early detection of problems allows preventive work to be carried out, which reduces the risk of major accidents and the need for expensive repair work. In the case of testing, information is obtained about various integral characteristics under static and dynamic test conditions. Static testing involves applying controlled loads to a structure and measuring its response (e.g., displacements, strains, and stresses). Dynamic testing involves subjecting the bridge to dynamic excitations and measuring its dynamic properties, such as natural frequencies, mode shapes, and damping ratios.