Research On Traveling Wave Effect Of Super-long Terminal Structure

With the development of the earthquake-resistant design of structure,the seismic design is gradually detailed.Based on the traveling wave effect of super-long structure,this paper analyzes the appropriate value method and basis of apparent wave velocity,summarizes the influence of traveling wave effect on structure stress,and makes a certain research on the design method of floor slab based on the analysis results of traveling wave effect.The main results are as follows:1)Based on the propagation characteristics of seismic waves in the soil layer,the method of determining the apparent wave velocity is analyzed.Based on the law of seismic wave propagation in a single soil layer,the calculation method of apparent wave velocity in a single soil layer is given in this paper.On this basis,considering the refraction law of seismic waves in different soil layers,the relevant literature and norms,the calculation method of apparent wave velocity in multiple soil layers is given.Combining with engineering experience,this paper presents a simplified calculation method which is suitable for engineering and is inclined to safety.On this basis,various parameters affecting the value of apparent wave velocity are analyzed in this paper.The analysis shows that the influence of structure length on the value of apparent wave velocity is negligible,but except for shallow earthquake,the influence of construction site type on the value of apparent wave velocity is negligible,and the lower limit of apparent wave velocity is close to the shear wave velocity of the crust.2)Based on the appropriate value of apparent wave velocity,the influence of traveling wave effect on ultra-long structures is analyzed.Based on the field geological prospecting of Xiamen airport,this paper selects appropriate apparent wave velocity and seismic wave,and analyzes the influence of travelling wave effect on Xiamen airport by considering different seismic waves,different input directions and different apparent wave velocity.The analysis results show that the total shear force at the bottom of the structure is almost unchanged,and the torsion ratio of the main structure increases by 8%at most after considering the traveling wave effect.The increase of internal force of each type of bar is less than 10%,and the distribution diagram of the increase of internal force of each type of bar is given.On the basis of the existing results,this paper analyzes and demonstrates the conclusion: when the traveling wave effect is analyzed by the time history of column bottom displacement,the influence coefficient of internal force is determined according to the 95% components that are less affected by multi-point excitation,so as to ensure the safety of the structure and avoid the abnormal increase of traveling wave effect caused by too small internal force of the components.3)Based on theoretical analysis and finite element verification,a floor design method based on principal stress is proposed.In this paper,based on the analysis of the floor stress,a floor design method based on the principal stress is preliminarily proposed,and a preliminary comparative analysis and mutual verification of the floor strength under the bidirectional stress state is conducted with ABAQUS.Finally,based on the engineering experience,the seismic performance indexes and strengthening measures of the floor slab are given.