Study On Wind-induced Response Of Hanging Basket Construction Of High Pier Bridge In Mountainous Area

With the development of the “The Belt and Road Initiative”,the construction of road infrastructure in the central and western regions of China has grown by leaps and bounds.There are more mountainous areas in the central and western regions.A large number of bridges need to be built across the canyons and rivers.Among them,the suspended casting method is a new technology used to bridge across the canyons and rivers and other zone that inconvenient to set up stent.The construction of the suspended casting method has the advantage of being unconstrained by the terrain conditions compared to the construction of the stent construction.Suspension casting method has been gradually promoted in China.However,the hanging basket used in the suspension casting method is a large-span steel structure,which has the characteristics of large flexibility and low self-vibration frequency.When the wind vibration frequency is close to the natural vibration frequency of the hanging basket,the hanging basket is prone to damage.Research on wind-induced response to hanging baskets helps design and application of hanging baskets.This paper takes the hanging basket construction by suspension casting method of Xifu Expressway Yanzhihe Bridge as the background.Study on wind-induced response of triangle hanging basket in the canyon terrain.The main research is as follows:(1)Based on the wind engineering theory and CFD technology,according to the topographic map,use Global Mapper and Imageware software to process the terrain around the Yanzhihe Bridge,and import Gambit software,divide the grid cells,set the boundary conditions,and use the Fluent simulation to calculate the canyon terrain wind field.(2)Select the 3# block hanging basket construction with the heaviest one as the research object.Perform a triangle basket static analysis.Create a triangle hanging basket model in Midas Civil,apply constraints on the model,and perform static analysis;the static analysis is carried out in two working conditions,namely the bridge construction process and the hanging basket walking process.Calculating and analyzing the stress and deformation characteristics of each part of the triangle hanging basket under two working conditions.The results show that the stress and strain of each part of the triangular hanging basket are all within a reasonable rangeunder the two working conditions.(3)For the simulation of the wind field,the static wind simulation is simulated by the UDF program in the Fluent software,and the pulsating wind field simulation is performed using the numerical calculation software Matlab according to the harmonic synthesis method.The Fluent software was used to calculate the wind speed and wind pressure on the surface to the triangle hanging basket.Obtain the wind pressure and wind speed parameters of the triangle hanging basket surface.Calculating the wind load.The wind load is applied to the triangle hanging basket established by Midas Civil for wind-induced response analysis of the triangle hanging basket.According to the results of wind-induced response analysis of the hanging basket,the horizontal displacement of the hanging basket in the walking condition under the action of average wind changes significantly,and the maximum value can reach 63.5mm.Under the action of pulsating wind,there is no significant change in the hanging basket in both conditions,but the damage of buffeting to the hanging basket cannot be ignored.