Model Test On Segmental Of Cable-pylon Anchorage For Ground Anchor Concrete Single-oblique-pylon Cable-stayed Bridge

The single-oblique-pylon cable-stayed bridge is beautiful.In the construction process,the oblique pylon has a huge overturning moment under the action of the gravity.Therefore,the synchronous construction of pylon and beam method is used to construct the single-oblique-pylon cable-stayed bridge.Setting temporary stent under the oblique pylon without cable and tensioning the cable when construct the the oblique pylon with cable,to resist the overturning moment and to improve the stress condition of the pylon.The synchronous construction of pylon and beam method can effectively shorten the construction period,save the project cost.But the construction process is complex.And there are many interference factors.Therefore,the construction technology requirements are high.At present,scholars have less research on the synchronous construction of pylon and beam of the single-oblique-pylon cable-stayed bridge,but the constructing the single-oblique-pylon cable-stayed bridge safely and quickly becomes an urgent demand.The anchorage zone of the cable-stayed bridge is an important area where the concentrated force of the cable is transmitted to the column safely and evenly.The anchoring point acts with great concentration.The stress state of the anchorage zone is complicated and the stress concentration is obvious which need enough attention.So far,scholars at home and abroad have not studied the mechanical behavior of the "I" section crossing-cable-pylon anchorage zone for single-oblique-pylon cable-stayed bridge.Based on the Guizhou Provincial Department of Transportation science and technology project "Furong River Bridge to anchor concrete cable tower cable-stayed bridge construction of key technology research"(project number 2016-123-048),around the Furong River synchronous construction of pylon and beam,cable-pylon anchorage zone mechanical behavior,this article carry out the following research work:(1)The finite element program is used to analyze the whole process of the synchronous construction of pylon and beam of the Furong River Bridge.The stress of the oblique pylon and the beam in the construction process and the bridge state is studied,and the reasonable timing of the temporary support under the oblique pylon is obtained.The change law of the direction of the resultant force of the oblique pylon in the construction process is studied by using the theory of plane intercrossing forces system.(2)Based on the dimension analysis method and the equation analysis method in the similarity theory,the proportional relationship between the parameters of the narrow scale test model and the real bridge prototype is deduced.Based on the combination of theoretical derivation and numerical analysis,the influence of gravity on the stress distribution of the narrow scale model and the real bridge is studied emphatically.(3)The mechanical behavior of the crossing-cable-pylon anchorage zone with "I" shaped section of single-oblique-pylon cable stayed bridge is studied by means of numerical analysis,1:4 narrow scale model test and real bridge test.The results show that the anchorage zone of the pylon is in an elastic state,which is safe and reliable under the combined action of transverse prestress and cable force.The crossing-cable-pylon anchorage zone with "I" section stress is clear,playing the concrete compression performance fully.Transverse prestress can effectively improve the stress of the pylon,and there is a large safety reserve.The "I" section than the rectangular section only increased the four smaller area of the flange,but it can improve the stress condition of the pylon section significantly.The "I" section pylon is beautiful,and it can play the role of hidden anchor teeth.