Shaking Table Test And Wind Tunnel Tests Study And Application Of Tall Tower Structures Of Airport

The control tower of Beijing Airport is the highest aero-tower built in China. This paper give the main research results about the tall tower building in seismic vibration and wind-induced performance taking the control tower of Beijing Airport as engineering background. The primary contents and results are as follows.1. Researching on the vibration experiment of the aeroelastic model of the control tower of Beijing Airport and other questions.This paper presents the similarity rule of the aeroelastic model of the control tower of Beijing Airport based on the similarity theory, and gets the similarity parameter of gas-dynamic elastic-model and the shrink ratio of the model parameter. On the base of similarity ratio using the similarity theory, this paper presents more research on the method on the condition of the test sample fulfils the similarity relationship approximately. The prototype control tower in this paper is made up by two kind of structure systems, the upper part belongs to steel-frame structure and the lower part belongs to concrete-tube structure. About this structure, it is difficult to give a model from the point of rigidity. This paper gives analysis on the similarity condition from the point of mechanics, and gets the material similarity from the wind-induced vibration similarity. Namely the model density, the elastic-module and other parameters can be modeled by the way of equivalent rigidity. When designing on the model of the control tower, we can unify the rigidity similarity and the figuration similarity and make the elastic parameter fusing into the rigidity distribution similarity. This new method comes over the shortcomings of using the rigidity similarity and the figuration similarity respectively. By this way, we can model the elastic parameter of the structure completely, and simplify the model execution. It can give the reference to other model design.The across-wind vibration of the tower is larger than the downwind vibration, the result from the test is consistent to that of the theory analysis. According to the lateral coefficient of the wind-tunnel test, we can get the lateral coefficient-angel curve of low muss-flow, and give the half-analysis method of the control tower with eight-polygon section when we neglect the influence of the lateral-coefficient if the muss-flow changes alone the height and the hypothesis of permit-stable is tenable, all above is based on a great deal of researches.2. Researching on the press experiment of the rigid model and the across-wind response of the control tower of Beijing airportThe figuration of the control tower changes largely, so the design-value enduring wind-press can't be ascertained using the tall tower building design criterion. In order to research on the anti-wind property of the control tower of Beijing airport, this paper does systemic research on the wind tunnel test of the tower model. A 1/80 rigid model of a control tower of Beijing airport is tested on the wind tunnel measuring on the press, and a 1/60 scaled aeroelastic model is tested . The distribution rule of the average press and the relativity are achieved. The result shows that the shape coefficient given in the design criterion is much safer. This paper presents the wind-press for doing tall tower building design.According to the research of the simulated border-layer wind tunnel tests on tall tower building model which has eight-polygon section,and according to a deeper research of some interrelated length and the lift coefficient, we get the distributive exterior press of the eight-polygon section of tall high building and tests results of the interrelated length. So we got the calculation of seismic response caused by vortex on the not-round section of tall tower building. This can give reference to the engineering deviser.3. Researching on the vibration experiment of the control tower of Beijing airport and other questions.When designing on the vibration test model, the geometry similarity, the physics similarity and the physics process similarity should be met. But all above are difficult to realize for the tall tower building. The main reasons are that the ratio of height to width is larger, and two kinds of structure systems are used. To the property of the tall tower building, one should take the following into consider when designing on the vibration test model: 1) To the control tower of Beijing Airport in which two kinds of systems are taken into considered, one can transform the elastic coefficient similarity into the rigidity similarity. So the elastic coefficient similarity is modeled completely and the simulating-condition is simplified. 2) Because the value of the height to width is large, it is difficult for the elements of different kinds to fulfill the geometry similarity at the same time. In the design process, one can merge the elements according to the principle of physics process similarity, so he can get the result that the rigidity and the mass of whole modelstructure is similar to that of the whole prototype. 3) The interior space is finite, it is difficult to fulfill request to the mass, so Sε≠1 and the model is distortion. So the acceleration coefficient similarity should be changed, namely by the way of enlarging the peak of the acceleration to fulfill the acceleration of the seismic. All the measures can be consulted when designing on the vibration test model.A 1/30 scaled reinforced mortar model of a control tower of Beijing Airport is tested on shaking table, and the dynamic characteristics and seismic response such as the eigen period, the vibration shape and the damping-ratio of each vibration model are measured. The property under the seismic action is mastered for the tall tower building. The test result shows that the light room and the upper side have the feature-branch effect. The primary frequency of the structure is far away from the primary frequency of the seismic wave, the horizontal seismic response is low frequency vibration, and the response is rather little. The vertical period of the principle part is far away from the predominating period of the ground movement, so the upper side has not the feature-branch effect. The first vertical frequency is 15 times the first horizontal frequency; it is close to high frequency vibration. To the tall tower building under the vibration action, the blowup coefficient gets lower and the displacement response gets larger when the seismic intensity gets higher, this shows that the model rigidity descends and the structure is in nonlinear condition. Though the rigidity is larger and the displacement is smaller when the structure is in linear condition, the light room of the upper side moves largely and the seismic acceleration is larger under the condition of the usual seismic intensity and the unusual intensity. In order to guarantee the aviation-controlling room to service normally, some measurements to lessen the seismic response should be done.Seismic response of each vibration mode of the tall tower model is obtained based on time-historians analysis method with respect to the reduced-scale model test. The modal damping ratio of the compound structure is discussed. The analysis of the calculation results reveal that the high-order modes contribute little to the seismic displace of the tower. however, the high-order models play an important role in the seismic shear force of the tower. A real mode-decoupling method can be used to solve the dynamic equilibrium under earthquake force. Revisions of influence coefficient in the seismic code for building in China are present in order to diminish calculation error. The result of research come up with the earthquake resistant design theory and set up model earthquake resistant analysis of this kind of structure.