Analysis Of Piers Stress And Structure Stability Of Continuous Rigid Frame Bridge During Incremental Launching

Continuous rigid frame bridge is a kind of Long-span Bridge which widely used in expressway construction in our country,the double pier and the hollow pier has it’s general used on the rigid frame bridge. The continuous rigid frame bridge is the statically indeterminate structure, which may appear the losse of prestress, displacement along the horizontal direction, the downwarp primary beam Shrinkage and other problems under the long term load in long term operation.Too much displacement along the bridge may lead to bridge bracing damage, reduce the stability of the structure and other problems.The most effective way to eliminate this effect is incremental launching on the beam when the bridge closure,which lead to offset of the bridge pier. Then the offset of the pier will be offseted, and the force of the bridge pier will reasonablely.The literature which research on incremental launching most limit in the study of force and the quantity of incremental launching,lack systematic analysis of incremental launching construction.The strength of bridge pier and the stability of structure is an outstanding problem in incremental launching construction.Too small force and quantity of incremental launching can not achieve the intended purpose while too large force and quantity of incremental launching may bring too much moment shear and tensile stress to bridge pier.Therefore,it quite necessary to analysis the strength of bridge pier and the stability of structure.The paper put forward the concept of basic force of incremental launching and obtain the force of incremental launching which used in research.Depend on Engineering case(the bridge of wujiaxiaohegou),the paper mainly analysis the construction of incremental launching by two aspect: strength of bridge pier and the stability of structure.Study the thickness and the height of bridge change influence on pier stress and characteristic value of the structure,and sum rule, provide reference for future engineering.