Shaking Table Model Test For The Tower Of Offshore Cable-stayed Bridge

With the development of economy, the role of bridge in infrastructure is becoming more and more important. The construction of the large scale bridge provides the convenience for communication between the various regions. And many areas affected by natural barriers are linked together. The bridge is the important component of the transportation line. The consequence of the damage to the structure of bridge is quite serious. Most areas in our country are in the earthquake regions, so the large-scale bridges constructed recent years across river and sea are under the potential earthquake threat. In this case, it is of great practical significance to study the earthquake resistance of large-scale bridges.In this paper, the large-scale deepwater cable-stayed bridge proposed to design and construction is studied through the shaking table model test. The structure vibration characteristics, dynamic response and damage law of the single tower structure of the cable stayed bridge under earthquake are researched considering the hydrodynamic pressure. Through the dynamic analysis of the tower structure, the influence of hydrodynamic pressure on the large-scale deep water structure is studied. The validity of reduced-scale dynamic model test on large engineering structure is explored. The whole process of dynamic model test on shaking table is discussed in detail. The design of the model and the implementation process of shaking table test are mainly introduced. Some conclusions are obtained in this paper, which provide valuable reference for the study of seismic resistance of bridges in the future.(1) The mechanical properties of the micro-concrete affected by water cement ratio, aggregate gradation, and the amount of rubber particles are researched through the material test. The experimental results show that the increase of the water cement ratio can significantly reduce the elastic modulus and compressive strength of the micro-concrete. The mechanical properties of the micro-concrete with coarse and fine aggregate is better than that with only one kind of aggregate. With the increase of the ratio of rubber particles, the elastic modulus and compressive strength of the micro-concrete are decreased. But adding too much rubber particles to the micro-concrete will increase the dispersion of the material. It is concluded that the micro-concrete is a kind of ideal dynamic model simulation material through the experiment.(2) Shaking table dynamic model test is an important method to study the earthquake resistance of engineering structures. Through the implementation of shaking table test on deepwater cable-stayed bridge with single tower structure, the vibration characteristics and dynamic response of the structure consisting of single tower structure and group pile foundation are researched under earthquake. Research shows that the bottom of tower and the lower cross beam is the weak parts of the structure. The dynamic characteristics of the structure are greatly influenced by the surrounding water. The tower structure is more easily damaged than group pile foundation, which should be paid more attention in the design.(3) The structure in the water will be affected by the dynamic water pressure generated by surrounding water under the action of earthquake. The influence of dynamic water pressure on the single tower structure of cable-stayed bridge is studied by numerical simulation. The results show that the hydrodynamic pressure reduces the natural frequency of the structure so as to increase the structural dynamic response under earthquake.