Research And Application Of Construction Control Of Long Span Continuous Rigid Frame Bridge In Coastal Area

The prestressed concrete continuous rigid frame bridge has the characteristics of high strength,good seismic performance,simple construction and strong spanning ability,so it is widely used in long-span bridges.Continuous rigid-framed bridges constructed by symmetric cantilever casting method are subject to various determinations and uncertain factors such as shrinkage and creep of concrete,differences in design parameters and actual values,construction errors,measurement errors,temperature changes,etc.The influence brings complex internal force and displacement changes to the bridge structure,so that the actual state of the bridge deviates from the ideal design state.In order to ensure the quality of bridge construction and bridge construction safety,it is necessary to ensure that the main beam shape and structural internal force of large continuous rigid frame bridges meet the design requirements after bridge formation,and bridge construction control is indispensable.This paper takes the Puba Port super large continuous rigid frame bridge as the engineering background,and studies the theory and method of large span bridge construction control.The main contents are as follows:1.The characteristics and development trend of long-span prestressed continuous rigid frame bridge are analyzed and summarized.The purpose,significance,content,theory and method of construction control are expounded.2.The large-scale engineering software MIDAS/CIVIL is used to simulate and simulate the full-bridge cantilever construction,and the various stages of construction are adjusted and controlled.The block casting of block 0# and block 1# and the bracket pouring and cantilever pouring of the side span are carried out.The technology such as the construction of the closure segment was studied.3.Combined with the measured data,the linear control and stress control of the bridge cantilever casting construction process were studied,and the concrete application of construction control theory in engineering practice was analyzed in detail.In the linear control,by analyzing the design elevation and the measured elevation,it is found that the difference between the two is small,and the requirements for the linear design of the bridge design and specification are met.4.In the stress control,from the change of the stress of each section,the top stress is greater than the bottom stress due to the prestressed position,and the stress change trend agrees well with the theoretical value;from the stress of each cross section,each cross section Both are subjected to compressive stress,and the maximum compressive stress does not exceed 12 MPa.The structure is in a safe state throughout the construction process,achieving the purpose of stress control of the bridge.