| The recent three decades witness numerous RC arch bridges in our country, utilizingon-falsework casting, cable-hoisting erection, steel reinforcement casting and rotationmethod. However, current construction methods have their own shortcomings ineconomy and durability. Referring to foreign information, combined method has greatadvantages in integrality, steel consumption and reduces the requirements to pulling andbuckling system. Recent years,3RC arch bridges has been built with free cantilevercasting method, but research related to the combined method has not been carried out yetinteriorly, thus, the mechanical behavior during construction progress is indeterminate.This study relies on the project “Research on the Design&Construction Technology ofRC Arch Bridge Built with Cantilevered-casting Methodâ€. The main work covered in thisthesis includes:â‘ Based on a trial design of300m RC arch bridge, due to the weak flexuralbehavior of the arch during cantilevered casting, this thesis puts forward a “forwardanalysis and stress control method with prediction mechanismâ€, which regard the stressof the arch as control object, the feasible region of the forthcoming cable force can becalculated, therefore the stretching scheme can be determined. Moreover, the simulationmethod based on ANSYS is given.â‘¡The cable force calculation method is given to make the joint consolidationmembers and closure segment assembly in initial prefabricated profile. Based on theUnstressed State Theory, the thesis proposed the cable-force conversion method betweenstages-merged simulation and in-stage simulation.â‘¢This thesis analyses the mutual effect of outer-wrapped concrete casting and thecantilever casting segments. By extracting the stress influence line, the profile controlmethod through cable-dismantling is given.All in all, a complete set of calculating methods have been given to achieve thereasonable mechanical state during construction, and it is suggestive to put the combinedmethod into practice. |
