Research On Vibration And Control Of Flexible Connected Fabricated Concrete Frame Structures Induced By Elevated Trains

This paper introduces the reasons for the vibration response of the assembled building frame structure system caused by the elevated train and the characteristics of the vibration.It summarizes the current status,research methods and current achievements of this topic at home and abroad based on the results of previous studies.The vibration of the surrounding environment caused by running trains has a great impact on people’s normal life.Previous studies focused on the vibration response of cast-in-situ structures.Therefore,it is necessary to study the vibration response of assembled buildings caused by elevated trains.In this paper,the semi-rigid connection assembly structure is taken as the research object,and the general finite element calculation software ANSYS is used for modeling calculation.When the finite element model is established,it is divided into two sub-models: train-bridge-pier and foundationsoil-fabricated structure,which are connected by the reaction force at the bottom of the pier.Run the upper sub-model to calculate the reaction force at the bottom of the pier and apply it as an external load to the center position of the lower sub-model pier.The vibration response of the three-story floor of the fabricated structure can be obtained through calculation.During the establishment of the upper model,moving loads were used to simulate train load excitation.The bridge and the pier were simulated by Beam4 elements,and the bearings were connected between them.The bearing structure was simulated by the Combine14 spring damping unit,and the pier bottom reaction force was calculated.In the pile foundation-soil-structure model modeling,the solid body and the pile foundation use Solid45 elements,which are coupled with the degrees of freedom on the contact surface;the bottom of the model adopts a fixed boundary,and the side adopts a three-dimensional viscoelastic boundary;Beam188 unit,the floor adopts Shell181 unit,the beam-column joint simulates semi-rigid connection through three axial and three rotation spring damping units.After the upper load is applied,the vibration acceleration and displacement of the structural floor can be obtained.Through calculation and analysis,it is found that the frequency range of structural vibration is mainly concentrated in the range of 0-40 Hz,which belongs to low frequency vibration;the horizontal vibration caused by the elevated structure caused by the elevated train is also more significant,and the vibration response is more sensitive than the vertical;The working conditions such as the distance from the centerline of the elevated structure and the nature of the soil have a certain effect on the structure vibration.As the node’s rotational stiffness increases,the amplitude of the acceleration spectrum gradually increases,indicating that the node’s semi-rigidity has a certain degree of vibration energy transmission.Impact.In the range of joint stiffness studied in this paper,the horizontal vibration response generally increases with the increase of the joint rotation stiffness,and the vertical vibration response is less affected by the joint stiffness change.The shallower the isolation groove depth,the larger the horizontal displacement change of the floor,and the smaller the vertical displacement change.Therefore,the design of the assembled concrete frame structure needs to control the depth of the isolation groove according to the function of the surrounding assembled structure.