Research On Mechanical Behavior Of Stress Ribbon Bridge Supported On Concrete Filled Steel Tube Arch

Arch bridge and cable bridge are main bridge types from the ancient. Stress ribbon supported on arch is an emerging bridge type in the last few years, from which stress ribbon bridge supported on concrete filled steel tube arch evolves exhibits the advantages of graceful appearance and reasonable stress, it reduces the damands for foundation and simplifies concrete load-transfer members of self-anchored bridges into abutments, improving utilization efficiency of structures. To understand mechanical property and computing method of this type of bridge and promote its applicaition, this paper carries out trial design, construction supervision and finite element analysis, the major work and results are as follow:(1) Trial design for a stress ribbon bridge supported on concrete filled steel tube arch and corresponding researches are carried out, referred to domestic current codes and rules, this paper checked the components and structures of the bridge, the calculations show the trial design meets mechanical requirements and it is mechanical feasible.(2) Referred to design and modeling ideas for existing stress ribbon bridges and concrete filled steel tube arches, modeling principles for stress ribbon bridge supported on concrete filled steel tube archs are put forward. monitoring data of arch rib defletion, stress variation law under main construction states tallies with calculation results., which indicates the finite element model proposed simulated mechanical properties of stress ribbon bridge supported on concrete filled steel tube arch well.(3) Linear elastic analysis has been applied for studying stability performance of stress ribbon bridge supported on concrete filled steel tube arch, it concludes buckling mode of the new type of bridge is lateral roll bucking, while its stability coefficients during the whole construction period are much larger than allowable value, suggesting this type of bridge exhibits an excellent stability performance.(4) Referred to existing camber setting method in bridge construction, this paper analyzes the applicability of camber setting method for arch ribs of stress ribbon bridge supported on concrete filled steel tube arch.the consistency of measured values and theoretical calculation values for final alignment suggests the method proposed is feasible.(5) According to existing codes and regulations, construction control precision indexes of geometric dimensions, alignments of steel tube arch ribs, alignments of stress ribbon are presented, through analysing the maximun deviations, it can be manifested that the imfluences imposed by the maximum alignment deviations on mechanical properties of strcuture are small, the construction control precision indexes are feasible.(6) Analyse main design parameters of stress ribbon bridge supported on concrete filled steel tube arch, results can be concluded as: along with the increasing of rise-span ratio, the axial forces in arch springing and stress ribbon and thrust force all reduces; increasing extroverted angels will weaken the support the arch does for the stress ribbon and decrease the stability with the buckling mode convert form out-plane into in-plane; the larger ratio of support section to suspension benefits mechanical performance of stress ribbon, while the thrust to foundation increases; thinner ribbon deck has advantages to mechanical performances of the bridge; the pre-stress system can reduces thrust force effectively; hinge joint and solid joint makes little different to mechanical, cast-in-place ribbon deck can reduce ribbon displacements and improve the stability performance.