Finite Element Numerical Simulation Analysis Of A 0~# Block Support Based On A Extradosed Bridge

Support is an indispensable link in bridge construction,which is the key to ensure the safety and quality of the main structure of the bridge.With the rapid development of bridges in China,more and more kinds of supports are built,and the height and scale of supports are increasing.Steel pipe supports are widely used in the construction of concrete bridges in China.With the increase of bridge scale,the use performance of steel pipe support is also put forward higher requirements,including the strength,stiffness and stability of the support.In order to reduce the cost in the project,the software is usually used to simulate the actual project in advance,and the overall performance of the support is analyzed and checked by the software simulation results.Based on the 0~# block support project of a bridge project in Hunan Province,this paper uses the spatial finite element simulation software MIDAS CIVIL to model and calculate the support.The results are checked and analyzed from three aspects:strength,stiffness and structural stability.Because of the different checking methods of the load-bearing capacity between the beam support and the beam bottom support in the 0~# block support,the 0~# block support is divided into two parts(including the lateral formwork support and the beam bottom support)to check the load-bearing capacity.The checking calculation of the bearing capacity of the outer formwork support mainly includes the strength and stiffness of the members,while there are long and thin bars in the bottom support,so besides the checking calculation of the strength and stiffness of the bottom support,the checking calculation of the stability.The maximum stress of the rod in the lateral formwork support is 137.6MPa and that of the steel formwork is 55.7 MPa,which does not exceed the allowable stress of A3 steel.The maximum vertical deformation of the lateral formwork support is 1.7 mm,which does not exceed the allowable deflection of the support.The maximum stress of the member in the support at the bottom of the beam is 162.5 MPa,which does not exceed the allowable stress of A3 steel;the maximum vertical displacement of the structure occurs on the longitudinal distribution beam,the relative displacement is 2.681mm,which is less than the allowable deflection of the longitudinal beam,indicating that the structure will not occur stiffness failure;the stability coefficient is 9.952 under the condition of buckling mode 1.The critical load is 2448.6 kN,which is larger than the maximum reaction force of 1184.9 kN.Therefore,the local stability of the steel pipe pile will not be destroyed.Therefore,the results of software simulation show that the design of the scaffold meets the needs of the structure.