VERIFYING THE CHOICE OF NUMERICAL MODEL OF A BUILDING BY IN SITU INVESTIGATION AFTER REALIZATION

Choice of the structural system, spatial position of the supporting elements as well as their section are defined in the state of project. The numerical model of a structural reinforced concrete building is based on some assumptions. Mechanical characteristics values of the materials used for the model represent theoretical data recommended by the regulations specific to each country. In the case of seismic design, the dynamic parameters of the structure are fundamental, taking into account or not soil-structure interactions phenomena. Validation of the numerical model in the dynamic domain is based on the deformability capacity, in relation with the inter-floor displacements to be respected according to the regulation. So, the dynamic characteristics period, mode shape and damping are the essential elements of a civil engineering structure to judge of its seismic behavior.In practice, often all the assumptions are not verified, the value of the concrete strength taken into account in the model is not always achieved during the execution phase. It becomes dangerous when the situation leads to a critical state of the work, which is sometimes difficult to make a diagnostic.A recent building located on the periphery of Algiers the capital of Algeria, is taken as an example to illustrate a proposal for experimental verification of a theoretical model. The selected building is located in Algiers department. The site is classified as a zone of strong seismicity. The building is designed and realized according to the assumptions required by the Algerian seismic code RPA99/2003. Numerical results were compared with in situ investigations by the ambient vibration technique.