Research On The Mechanical Characteristics Of Key Components Of Steel Box Basket-handle Arch Bridge During Construction

Bridge construction monitoring is an important part in the construction process of long-span steel box basket-handle arch bridge,and its purpose is to make the completed state of the bridge meet the design and specification requirements as much as possible.This paper takes the Weihe River Bridge of East Fourth Road,Caijiapo Shanxi Province(hereinafter referred to as the Weihe Bridge)as the engineering background,and uses the forward finite element model to simulate the key construction stage of the Weihe Bridge.It mainly studies the influence of temperature on the assemble of steel box arch ribs,the optimization of suspenders stretching sequence,the monitoring of suspenders stretching process,the research on the removal scheme of arch rib temporary supports and steel pipe support of bridge deck system,the stress distribution in Suspender anchoring zone and the mechanical characteristics of the connection of pin connection.The main research work and results are as follows:1.The engineering situation of Weihe Bridge and the division of arch rib segments are introduced.The influence of temperature on the location coordinates of arch ribs is analyzed,and a correction method for the location coordinates of arch ribs considering the influence of temperature is proposed.2.The arrangement of suspenders and the structural of suspenders and ear plates of Weihe Bridge are introduced.The allowable error angle of the upper and lower ear plates is analyzed,and the measured angle and theoretical data are compared and analyzed to better control the inclination angle of the upper and lower ear plates.This paper analyzes the different tension schemes of the Suspender of Weihe bridge,and gets the optimal scheme suitable for the suspenders stretching of Weihe bridge.The method and principle of measuring the cable force of the suspender are briefly described,and the cable force calculation formula considering the bending rigidity of the suspender without using the bending rigidity is derived.This paper study on the tension scheme of the same group of suspenders for asynchronous tensioning,and puts forward some strategies for ensuring the cable tension uniformity of the asynchronous tensioning scheme.3.This paper introduces the simulation method of the removal of arch rib temporary supports and the matters needing attention in the process of removing arch rib temporary supports and bridge deck support.This paper puts forward an analysis mode that firstly analyzes the synchronous decentering scheme,then judges the feasible decentering frame scheme according to the result of the synchronous decentering scheme,and finally obtains the optimal decentering scheme by comparing the advantages and disadvantages of each scheme.The analysis mode can provide reference for the steel pipe support removal scheme of other bridges.4.The stress distribution in the D1 suspender anchorage zone of Weihe Bridge is studied,and the stress concentration phenomena are found in the weld of the stiffening rib of the ear plate,the two sides of the round hole of the ear plate,the root of the ear plate,etc.The fatigue problem in the anchoring area of the suspender is analyzed briefly,and the distribution of the main damage areas in the anchoring area is determined.Detailed simulation of plug-in pin shaft connection is carried out,and the stress form of this type of connection is determined.