Study On Mechanic Properties Of Joint Configuraion Located At RC Arch And Stiff Skeleton

Currently,the cantilever assembled method and the cantilever construction method were adopted to erection the long-span concrete arch bridge in China.Though cantilever assembled method could reduce the requirements of cable hoisting system, there are disadvantages, such as excess piecing, poor unity, badly distributed stress, more cracks and undesirable durability.The arch constructed by Cantilever Construction Method has a good nature of integrity,but the longer the cantilever, the more difficult to form a ideal shape of the arch and the more dangerous during the period of the construction.the requirements for anchor systems is also higher.In Japan,many large-span concrete arch bridges were built by adopting the cantilever casting and stiff skeleton method combined construction technique.The arch ring constructed dy this method has a good nature of integrity,In addition,The shape of the arch is easy to control and the requirements for the Lifting capacity of the cable hoisting system is lower.Compared with the complete stiff skeleton method,the combined construction technique can reduce consumption of steel.The background project was constructed by the cantilever casting and stiff skeleton method combined construction technique(that is,along the foot of the arch to the top of the arch,the arch ring is concreted with cantilever method in the first several stages.Afterwards installing a piece of stiff skeleton to shut the arch,finally casting concrete encased the stiff skeleton),The reinforced concrete arch bridge constructed by the combined construction technique, Which stiff skeleton is located at the top of the arch,and the stiff skeleton must anchored in the limited volume of concrete of the cantilever arch section.Compared with the complete stiff skeleton method,The joint of arch ring built by combined construction technique has bad bearing capacity.The joint of arch ring built by combined construction technique is the key section to the design of the bridge.This paperis aim at to study the mechanical behavior of the joints.The main research contents as follows:①According to the construction design chart and construction procedure chart of The background project,carried out the main arch construction phase simulation.②According to the simulation results of construction phase of the main arch. Optimized the structure of stiff skeleton based on its stability and the shear bearing capacity of the joint③Reference the study results of SRC bond-slip theory around the word,Carried out the mechanical properties theory analysis of joint.④Adopted the finite element software ANSYS to establish fine entity model of the joint,which considered SRC bond slip, according to the analysis results of the finite model, carried out the stress distribution analysis of concrete.Verified the length of steel embedded analytical results and presented design recommendations of joint structure.⑤Designed and made a local full-scale test model for axial compression and another for shear.carried out the joint experimental study of axial pressure and shear action,the results of the test and the results of the fine FEM considered the bond-slip between setion and concret were compared.