Experimental Study And Finite Element Analysis On A Model Of Cable Tower Anchorage Zone Of A Bridge Tower

With the continuous development of long-span cable-stayed bridges,the structure of cable-stayed bridge pylon is also put forward higher requirements.As the cable tower anchorage zone connecting the superstructure and cable tower structure of cable-stayed bridge,it is the key part of the control design because of the stress concentration and complex structure.This paper takes the anchorage zone of the pylon of the Yangtse River Highway Bridge under construction as the object of study,combined with the actual situation,the finite element analysis and experimental study on the anchorage zone structure of the anchorage system of the grouped cable tower are carried out.The main research contents and conclusions are as follows:(1)In this paper,the finite element analysis software ABAQUS is used to analyze the anchorage segment model of the grouped cable tower in detail,The theoretical results of grouped anchor structures under different load conditions are obtained.The results are as follows:1)Steel beam,steel anchor plate,vertical plate,steel anchor box,webs and the top and bottom of the stress to remove the stress concentration,were less than the allowable stress of steel under load working condition 1 and load working condition 2.2)Steel beam,steel anchor plate,vertical plate to remove the stress concentration,were less than the allowable stress of steel under load working condition 3 and load working condition 4.Steel anchor box,webs and the top and bottom of the stress to remove the stress concentration,less than yield strength.3)Under four load cases,The maximum compressive stress of concrete pylon is less than the design value of compressive strength.The deformation shape of top and bottom baseplate of steel beam is similar.(2)The test model intercepts the sixth steel beams of the pylon according to the most unfavorable force principle,scale model is made according to 1:6 proportion.Experimental model study on model steel beam,steel anchor box,the top and bottom web vertical baffle the stress and displacement of the top and bottom of steel beam,concrete pylon stress under the action of four load cases.The stress characteristics and stress distribution law of the area are obtained.The conclusions are as follows:1)Theoverall stress level of the steel beam is low,and the plates are in the state of elastic working under load working condition 1 and load working condition 2.The stress on the steel anchor box N3 is always larger than that on the N4.2)The Mises stress of each member of the steel beam is less than the allowable tensile and compressive stress of the steel,which shows that the steel anchor box can continue to bear the design load under load working condition 3.Except for the N3 plate,the stress values of the other members of the steel beam are less than the allowable stress of the steel.3)Under four load cases,the midspan displacement of the steel beam roof is larger than that of the upper section,the displacement of the roof in the upper section is larger than that of the bottom plate.The relative displacement of the bottom plate of the steel beam is positive,and the relative displacement of the central part of the roof is negative under load working condition 4.4)Each plate of steel beam stress,displacement of roof and floor,and concrete pylon stress and theoretical values and measured values are consistent on the whole.(3)In order to ensure the safety of the structure,verify the steel beam bearing plate and concrete pylon under four load conditions are always closely connected.Established contact element between the tower and steel beam,the concrete column and steel beam bearing plate with contact surface is simulated,security at the junction is analysed.Analysis shows: The tower and the bearing plate surface is in compression under the action of four load cases,concrete and steel beams are not separated from each other.Due to the existence of pre tightening force and boundary force of anchor rod,the static friction of tower-steel beam joint surface is huge.The static friction force does not reach the bonding and faces the boundary friction force,there is no relative slip between the interfaces,the tower has always been closely connected and rigid beam.