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Due to the relationship between the elevation of the roads on both sides of the strait and the adjustment with the surrounding landscape, the elevation of the deck of the bridge is restricted when the bridge is designed. When the water level rises below the superstructure of the sea-crossing bridge, the main guardrail of the bridge may be partially or completely submerged in the water, and the superstructure of the bridge is affected by huge waves, which threatens the safety of the bridge. Based on cloud computing technology, this paper establishes a digital model of the crossing bridge and monitors the specific state of the bridge through the simulation of the bridge, collects various data of the bridge, analyzes the dataset, and analyzes the crossing bridge. This paper analyzes the correlation between the magnitude of the wave force and the height of the wave impact on the bridge superstructure and studies the relationship between the lift resistance coefficient and the impact height. The analysis of the lift coefficient and drag coefficient of different water depths in the case of 20-year operation shows that the height of the main beam where the large wave force acts has two values, 2.0 and 3.0 m in the case of 20-year operation; in case of 50-year working conditions, it is 2.5 and 3.0 m; in case of 100-year working conditions, the lift coefficient is 1.5 and 3.5 m, and the resistance coefficient is 2.0 and 3.5 m. Under the three water depth wave conditions, the fluctuation range of the lifting resistance curve is large when the water level depth is 10 m. Once a large wave occurs, the wave will not spread well due to the shallow current, which will cause a large wave force impact on the bridge. Therefore, when choosing a bridge, it is not recommended to build under a water depth of about 10 m. Optimizing the design of the main beam according to the analysis results of this paper will help to improve the ability of the bridge main beam to resist wave loading and provide a reference for seeking effective measures to reduce the impact of waves.

Abstract:The bridges will be in service in a complex environment for over 100 years under the increasing traffic loading. So the long-term performance determines their safety and durability. Limited by the test condition and ability, present researches are mostly focused on the natural environment exposure tests and artificial environment acceleration tests for materials and components. According to the service conditions and load characteristics of the bridges, the accelerated test system was developed for bridge structure under combined environment and loading. This test system consists of three parts, including a large environment box, loading system and monitoring system. The environment box is 32 m long, 4 m wide and 3/10 m high. It is divided into 5 working bins which can be used alone or in combination. The simulation environment includes high temperature drying, low temperature freezing and thawing, damp cold, high temperature cycle, salt fog, rain, carbonation, temperature and humidity alternating and optical spectrum light aging environment. The servo static and dynamic loading system adopts Servotest actuators with loading tonnage from 400 tons to 50 tons. And the total tonnage is 1200 tons. Aided by the prestressed concrete reaction wall, steel structure frames and the anchor system, the external loading system can exert dynamic and static loads on the bridge structure in the environment box. And the non-contact nondestructive monitoring system can real-time monitor and measure their long-term deformation, internal force, cracking and other damage. This artificial acceleration test system can support the Chinese Long Term Bridge Program, and improve the safety, durability, reliability and long service life of bridges and other civil engineering.