Research On Application Technology Of SWFC Continuous Rigid Frame Bridge

This essay is studying on the basis of the construction projects of the Transport Ministry-"the continuous rigid frame bridge SWFC composite structure in the Tibet area"(2013318 J15 390),conducting the in-depth study about the mechanical behavior of SWFC composite continuous rigid frame bridge that introduced by the research group.The main research work and conclusions are as follows:(1)The concept of SWFC continuous rigid frame bridge,which is in the positive moment section of continuous rigid frame bridge set on the bottom surface of the flat plate(S-steel),and connected directly to the welded stirrup and flat steel plate,wearing steel skeleton;in the continuous rigid frame bridge pier beam setting with steel mesh surface configuration.In the negative moment section part,the distance(W-web)should be set and the section with high content of steel fiber should be reinforced by concrete(F-fiber)concrete(C-concrete)deck.For the section,the SWFC composite continuous rigid frame bridge is made of box section and TT section.The TT section is used in the positive bending section.Negative bending moment section adopts pillar top box section.(2)Analysis the enhancement mechanism of SWFC continuous rigid frame bridge's structure.S-steel could enhance the anti-cracking ability of crack resistance of the structure and decline the development of cracks and slow.The concrete constraint of W(mesh)is constraints on the face,which the effect of crack resistance crack constraint is stronger than the line constraint of general rebar.F(hybrid steel fiber)can suppress micro cracks of the internal concrete,which the tensile strength of steel fiber reinforced concrete is far higher than that of ordinary concrete.(3)In terms of SWFC composite continuous rigid frame bridge,discuss the complex modeling method,which uses SolidWorks created complex parts and save in the format of.igs,then import into the Abaqus/CAE establishing the part building.Assembly may exist gaps.For the bridge piers and diaphragm plate,it should adopt the way of stretching,which could avoid an error that occurred by late gap because of meshing.(4)Because of the current research result of the application of reinforced concrete constitutive unity,analysis the positive section of mechanical process and ultimate bearing capacity which under the steam car load situation of across the cross section and the pier top section in the loading background of crossing the CKS bending moment and the pier top negative bending moment.The result of analysis shows that,in the loading situation of positive bending moment,the main girder maximum deflection is 13.5mm under the gravity and is 20.3mm under the one time weight of carload.Under the influence of self-gravity,the stress of the outer arc girder is significantly higher than the inner surface.The inner part of the lateral region of the middle straddle is cracked,and the inside is basically no crack.With the load increasing,the center of plate across cracks on both ends of the area expands gradually.More across the region near the crack is to deepen and extends to the internal.When loading to 12 times of the action of automobile loading,bottom plate began to yield.Most web cracks have been well versed in.At the top of the piers and collar beam location,on the cross direction began to appear in the plastic area.When loading to 14 times of the carload,the steel bars of the cross section IV(the bottom enhancement area)yield,and the pressure zone concrete is crushed.The bridge was completely destroyed.Under the negative bending moment at the top of the pier loading cases,2 # pier top section and side span cross section under vehicle load in the mechanical behavior and the loading process and ultimate bearing capacity of normal section were carried out the analysis.In the action of automobile loading is loaded into the 34 times,2 # pier 1 side across most web cracks has been well versed in.Section IV area(at the bottom of the reinforced area)reinforced began to yield,the top of the bridge pier by across to the right direction and is part of the beam began to appear the plastic area.The pressurized zone concrete was crushed when the load was carried on the 36 times of the load.The bridge was completely destroyed.(5)In terms of SWFC composite bridge in plateau mountainous area,research in detail and discuss the technology of construction about SWFC composite bridge from the concrete construction of steel production,installation and transportation technology,measures to ensure the support scheme of unloading technology in the alpine region and construction monitoring methods for the future practice of a combination of structural engineering in the plateau mountain.