Performance parasismique des poteaux en tube d’acier remplis De Béton.

Abstract

Mixed steel tube poles filled with concrete are increasingly used in the design of modern multi-stage structures (lathes). The investigations developed in recent decades confirm their beneficial use, they are used as a component of a structural system given excellent ability to absorb and dissipate energy or as a method of reinforcing damaged structures in reinforced concrete such as post or bridge stack , by reinforcement by steel lining. The confinement of concrete by steel pipe has unavoidable technical and economic advantages in the building and public works sector. The majority of the universally established codes ACI, AISC, EO4 have incorporated the methods of analysis and design for the calculation of mixed poles in the regulation, without a repair guide. The current Algerian regulation RPA 99 suffers from this lack. The research focuses in this axis. Moreover, the mixed poles contribute to provide the structural elements with a high resistance, a high ductility and a high rigidity, with a remarkable optimization of the materials implemented In addition to these advantages, the steel tubes also serve as formwork thus reducing the cost and the duration of realization. The current philosophy is that under dynamic load plastic hinges develop in certain critical sections which must be selected beforehand; and it is essential to know the resistance and the deformation capacity of each structural element to ensure that the mechanism of ruin develops in the desired way. In this context, the structural elements are dimensioned so as to be able to withstand lateral displacements without compromising the overall balance of the structure. We present in this thesis: •A bibliographic study with a synthesis of the main existing confinement models, analytical and theoretical. The influence of the main determining parameters in the evaluation of the gain in resistance and deformation. Estimation of the bearing capacity of mixed columns. • An experimental program carried out at the level of the civil engineering laboratory. Eighteen (18) steel tube specimens filled with self-placing concrete were tested for uni-axial compression, for different parameters, with incremental force-displacement acquisition to failure. Four (04) non-confined concrete specimens were subjected to a standard compression test. The analysis and discussion of the results allowed us: to establish a law of behavior of the composite material. To refine the correlation between theoretical and experimental model. • A study on a real case of bridge was applied to estimate the levels of performance (capacity of resistance and deformation) after reinforcement of the stack of this structure by the technique of lining and thus to value the gain in resistance and deformation.