Study Changes In The Radius Of Curvature Continuous Rigid Frame Bridge On Influence Law

As high-level highway has been widely constructed,curved continuous rigid-frame bridge has massively built due to its advantages which can live up to the advantages of mountainous region. However, due to its complicated structure stress, it makes the calculate its internal force and deformation major issue to deal with. Hence,it is perfectly necessary to make a research on structure calculation of curved continuous rigid-frame bridge.At present, exclusive computing software on bridge at home is mainly graphic analysis program which can not fit curved continuous rigid-frame bridge. Software MIDAS from South Korea is able to calculate and analyze the space of curved continuous rigid-frame bridge. This paper calculates and analyzes a newly-built curved continuous rigid-frame bridge by applying MIDAS, furthermore changes plan curvature of its main girder. To calculate internal force and deformation of plan curve radius of the curved continuous rigid-frame bridge at different constructional stages and make an analysis on the calculation results, this paper employs MIDAS with an aim to study the influence of curvature changes on internal force and deformation of main girder. Hence, this paper is going to make the following tasks:1. According to the process of construction, it is going to calculate internal force including bending moment,torque and deformation including torsion and radial displacement of main girder at different constructional stages under the circumstances of dead weight, prestressing force and working load.2.On the assumptions that the pier height,span length of main girder,prestressing steel are unchanged, it makes comparison and analysis the structural internal force and deformation of newly-built bridge at the stages of maximum cantilever state, bridge-constructed and live load function works. The result shows that when curvature radius changes from 584 m to 200 m which is the minimum of plan curve radius of highway, curvature goes less and less which leads bending moment of main girder goes less, and maximum increment is maximum bending moment which occurs when live load works which can be neglected due to 7% increment bending moment. Vertical deflection of main girder, the biggest one in all spans, increases while curvature radius slows,which has a small increment as a whole and this can be neglected.Maximum torque and radial displacement of main girder, which occurs at pier top, rapidly increases as curvature radius slows and has relatively big changes that can not be neglected in calculation and construction.Torsion angle of main girder becomes maximum near the a quarter span at the stage of maximum span and becomes maximum at the middle span in the bridge-built stage, which both increase fast while curvature radius slows and have big changes as a whole. This needs to be paid attention by putting setting up reverse camber into consideration. While under the circumstance of live load, torsion angle reduces, which can neglect the influence of curvature radius.This paper offers reference on the design, calculation and construction of curved continuous rigid-frame bridge and makes contribution to comparative analysis on different span length and pier height of curved continuous rigid-frame bridge.