Construction Control And Temperature Effect Analysis Of Continuous Rigid Frame Bridge In Mountain Area

In recent years,continuous rigid-frame bridges have been widely used in mountainous areas with deep trench gorge geomorphology and rugged terrain due to their excellent mechanical performance,economical cost,ease of construction,and comfortable driving,but such bridge construction procedures It is more complicated,difficult,and risky.To ensure construction safety and high-precision design goals,it is essential to control the construction of long-span continuous rigid frame bridges.Based on the background of the Middle Road Bridge in Diqing Tibetan Autonomous Prefecture of Yunnan Province,this thesis studies the construction control and temperature effect of the continuous rigid frame bridge in the mountain area.The main contents and results of the research are as follows:(1)The key problems of bridge construction control and the classical calculation method of finite element numerical simulation of bridge structure are reviewed.According to its applicability,the theoretical method of formal assembly calculation according to the actual situation of the project is selected.The control measures of the construction process and its influencing factors are selected.Conducting analytical research provides strong support for the establishment of a construction control system.(2)Using the forward analysis method to simulate the middle bridge,the finite element model of the middle bridge was established,and the pre-camber value of the main beam of the middle bridge was obtained according to the simulation result combined with the cosine curve distribution method;the bulk density of the concrete was revealed by simulation calculation.Based on the influence of parameters such as elastic modulus and prestress on the stress and deflection of the main beam,the stress and line monitoring scheme of the main beam was established,and the construction control system of the middle bridge was established.(3)Based on the measured data of the preloading of the hanging basket,the load-deformation relation is obtained by fitting,and the load-deformation relation is modified based on the theoretical measured data.On this basis,the modified relation is used.The deformation of the hanging basket during the construction stage was accurately predicted,which improved the precision of the main beam linear control.Based on the results of finite element analysis and field measured data,the optimal top thrust of the middle bridge is determined,which effectively improves the internal force state after the bridge is closed.The construction control results of the Zhonglu Bridge show that the main beam shape and structural stress control effect is good,the structure after the bridge is safe and reliable,the line shape is smooth and smooth,and the expected goal is achieved.(4)The Zhonglu Bridge is located in the V-shaped mountainous area,and the temperature effect on the stress and deflection of the main beam structure is more complicated.Based on a large number of field temperature measured data,the measured temperature field of the continuous rigid frame bridge girder under the V-type mountain topography is obtained.Based on the finite element analysis results,the main beam temperature field and the main beam are studied.Under the condition of no pavement layer,the temperature effect under half of the conditions of sunshine,sunshine,and overall temperature rise.