Research On Dynamic Behavior And Seismic Response Of Single Pylon Cable-stayed Bridge

Huang Pi Houhu bridge of Wuhan is a single pylon and single cable planecable-stayed bridge, which is constructed with pre-stressed concrete box girder. Itsspans are90+128m. The connection mode of the main girder, bridge pylon and thepiers of the single pylon cable-stayed bridge, determines the effectiveness of themindshare among the internal system components. For single pylon cable-stayedbridge of different connection form among pylon, girder and piers, studying thedynamic behavior and seismic performance is of practically significant. In this paper,the author has mainly done the following research work.(1) The overall arrangement of single pylon cable-stayed bridge and thebehaviors of the different structure system have been discussed.(2) For single pylon cable-stayed bridge of different structure system, the authorhas studied the modeling method in analyzing dynamic behavior s. Take Huang PiHouHu bridge of Wuhan (rigid-frame structure system, auxiliary pier is set at the sidespan) as the background, the boundary conditions of the pylon, beam and pier havebeen changed, finite element analysis software--Midas Civil has been used toestablish a rigid frame model--half floating beam model, floating model, pylonconsolidation model and a side span rigid frame model2with no auxiliary pier hasbeen established at the same time, as to find the differences of the two patterns.Multiple Ritz vector method has been used to analyzes the dynamic behavior s of thefive different model, and compare the differences of the behavior value.(3) Standard acceleration response spectrum has been used as the input spectrumcurve, to analyze the response spectrum of the five different models. Take the rigidframe model1as an example to calculate the eight (one dimensional-three, twodimensional-two and three dimensional-three) seismic response of the single pyloncable-stayed bridge in different combination, and have obtained the general rule ofseismic response. The author has calculated the earthquake response of five differentmodel in the condition of six (Elevated direction+0.3times of Transversedirection+0.3times of vertical direction), and has compared the differences of thedisplacement and internal force response among different control sections.(4) The modified Taft wave has been input as the ground motion, to do thedynamic time history analysis on five different models under the consistent incentiveeffect condition. Take rigid frame model1as an example to calculate the earthquakeresponse of the single pylon cable-stayed bridge in eight different combinations, and has compared the differences between the rule of seismic dynamic time historyresponse and the rule of the spectrum response. Five different model’ earthquakeresponse in the condition of six (Elevated direction+0.3times of Transversedirection+0.3times of vertical direction) have been calculated, and the differencesbetween the displacement, internal force response in different control section and thatin response spectrum have been compared.Considering the randomness of the seismic action, the calculation result of twomethods has obvious difference. For safety’s sake, whenever analyzing the seismicresponse of the single pylon cable-stayed bridge, two methods ought to be combined,and comprehensive consideration should be taken to get satisfactory results.