Study On Construction Control Of Self-anchored Suspension Bridge Across The Yihe River In Luoyang Kaituo Road

In recent years,with the continuous development of long-span bridges in our country,the self-anchored suspension bridges are widely favored by engineers for their beautiful appearance and strong topographic adaptability.Because of the particularity of the structure system of the self-anchored suspension bridge,its construction process also shows relatively complex nonlinearity,so the construction control of self-anchored suspension bridge is particularly important.This paper takes the Self-anchored Suspension Bridge across the Yihe River in Luoyang Kaituo Road as the research object.On the basis of summing up the theoretical results of construction control at home and abroad,the construction control of the Self-anchored Suspension Bridge across the Yihe River in Luoyang Kaituo Road is studied.The main research contents and conclusions are summarized as follows:(1)The development process of the suspension bridge calculation theory is introduced,and the theory of finite element iterative analysis is introduced in detail.The finite element real bridge simulation of the bridge was carried out by Midas Civil,and the lining theoretical internal force of each locating stage was obtained.Combined with the monitoring data,the sling force of each construction control stage is calculated by the unstressed cable force calculation method,and compared with the model theoretical data,the accuracy of the method is verified.(2)Two methods for calculating the main cable shape of the suspension bridge are introduced in detail.Combined with the calculation results of the bridge,the difference between the two methods is obtained.The difference between the parabolic theory and the catenary theory is obtained,that is,when the span of the suspension bridge is large,priority is given to select the catenary theory to conclude the main cable design.The finite element main cable shape of the bridge was checked,and the main cable shape under the condition of free air cable was determined,and theoretical data was provided for the setting position of the main cable.(3)Exploring the tensioning method of slings,introducing the advantages of the stress-free state method in the determination of the sling force of the reasonable bridge and the selection principle of the tensioning sequence,and the specific analysis of thetension-free state of the hanger method In order to solve the unstressed length of the cable.Based on the selection principle of the sling tensioning sequence,the practical simulation method of the stress-free state method is used reasonably,and the suspension tensioning scheme of the bridge is drawn up.(4)Introduced the construction monitoring principle in the adjustment phase,adjusted the construction plan by monitoring the main cable before the adjustment,and determined the actual adjustment plan.The length of the sling is controlled by the cable clamp positioning and the change of the main cable displacement before the cable.In the adjustment phase,the internal force and deformation monitoring of the boom control point and the main tower control point were carried out respectively,which verified the rationality of the unstressed state method.