Research On Key Technology Of Prestressed Concrete Cable-stayed Bridge During Construction

With the increasing demand for long-span bridges,cable-stayed bridges are more and more widely used in China.At the same time,the design theory,structural analysis and construction technology of cable-stayed bridges are constantly developing.However,modern cable-stayed bridges belong to high-order statically indeterminate structures,which are difficult to design and construct.In order to make full use of the advantages of cable-stayed bridges,it is very important to select reasonable cable forces for completion of bridges.At the same time,we should choose the appropriate construction scheme,accurately calculate the cable forces at all stages of construction,and monitor and control the bridge in real time.One is to ensure the construction safety,the other is to close the state of the bridge after construction with the preset state of reasonable completion.Therefore,the technology and control in the construction process of cable-stayed bridge are particularly important.Based on the Shuiyang River Bridge project in Xuancheng City,this paper systematically studies the design cable force calculation,key construction technology and control and monitoring scheme of the prestressed concrete cable-stayed bridge.According to the cable force of completed bridge given by design institute,the minimum bending energy method is used to calculate and check the cable force of reasonable completed bridge state.Then,through the forward iteration method,the forward analysis of construction is carried out by the structural engineering analysis software Midas,and the cable force value of each construction stage is calculated,which has reference value for the design and calculation of general cable-stayed bridge.Value.Furthermore,according to the measured data,the least square method is used to estimate the parameter error,so as to achieve the purpose of construction control.According to the actual bridge example,on the basis of determining the construction process of the main tower,the key construction technology of the main tower column and cross beam is studied.This paper systematically expounds that the key technology of tower-column construction lies in the construction of tower-column and cross-beam,designs and checks the turning-over tools for tower-column construction,and also analyses the matters needing attention and checking contents in the construction technology of cross-beam.It has reference value for the design and calculation of general concrete tower and column construction.On the basis of explaining the construction process of the superstructure of the main bridge,the construction process and construction technology of the side span closure section and the middle span closure section are studied.The key technologies are the erection of the support system,the locking of the closure section and the weight before closure.In view of these construction techniques,this paper designs and calculates the support system form of the full support,and systematically discusses the locking operation of the closure section,the selection and calculation of the counterweight,which is of guiding value for construction.