The Influence Of Foundation Settlement On Large-span RC Trussed Arch Bridge And The Reinforcement Research

The deck system,superstructure and substructure appear serious disease under the effect of foundation settlement,which will have a great influence on the bearing capacity of bridge.Combined with the Swivel Bridge of Dinglong-highway,by means of investigation and admeasurement,theoretical analysis,finite element simulation and comparative analysis,the study about the influence of foundation settlement on large-span RC trussed arch Bridge and the reinforcement research are performed,and the corresponding reinforcement measures are verified.First of all,the common forms of abutment foundation are introduced and the settlement mechanism are analyzed of trussed arch bridge.Begin with the results of field investigation,the existent diseases of deck system,superstructure and substructure are counted,and the root causes of them are analyzed using the principle of mechanics.Further,the common forms,mechanical properties and characteristics of trussed arch bridge are researched and summarized,the theoretical calculation methods of different members are deduced,and the loading effect and resisting effect of main section are calculated.Secondly,the numerical model is established by using the finite element program,under the symmetrical and eccentric load,with the increase of the uniform settlement,the mechanical behavior and changing regularity of the beam and brace are studied.Through comparative analysis,under the symmetrical and eccentric load,the different effects of uniform foundation settlement on beam and brace are summarized respectively.Based on that,under the symmetrical and eccentric load,with the increase of the non-uniform settlement,the mechanical behavior and changing regularity on beam and brace are studied.Through comparative analysis,under the symmetrical and eccentric load,the different effects of non-uniform foundation settlement on beam and brace are summarized respectively.And the different changes of bearing state because of uniform and non-uniform are researched,the causes of the main components disease are researched and compared with the results by field investigation.Finally,the reinforcements are put forward according to theoretical analysis results and field investigation.The stress and displacement of each control section are studied through the static testing;The frequency,damping and the dynamic magnification factor are tested through the dynamic testing,and the relationship between dynamic magnification factor and vehicle speed is researched;The effect of strengthening technology is verified by comparing the measured data with the theoretical values before and after reinforcement.The results show that the stress state of the structural members is changed,and serious damage will be found in deck system,superstructure and substructure because of foundation settlement on large-span RC trussed arch Bridge;Different settlement conditions have a variety of effects on the beam and brace;The reinforcement technique proposed in this paper is feasible and effective,the results would be the scientific reference to the design and reinforcement of the similar bridges.