Mechanical Performance Analysis Of School Buildings In The View Of Robustness

Robustness of the structure is now a hot research topic in the field of structural engineering. The domestic and foreign scholars put forward many significant definition and quantitative methods of robustness, but there is neither generally accepted definition nor quantification of robustness. This paper attempts to propose new definitions and the corresponding quantitative methods of the robustness basing on the researches that focus on the importance coefficients of components. At last, the author applies the robustness theory to analyze characteristic of the school building collapsing under earthquake.Firstly, the definition of the vulnerable components is proposed in this paper; meanwhile, the calculate formula of the vulnerability coefficients of components considering the interaction of axial force, shear and flexure when the component is composed of a single material is also analyzed. And based on the research on the force strength of the rectangular reinforced concrete (RC) bars that were under the combined loading indicated axial force, shear and flexure, a unified formula is proposed in this paper to calculate the vulnerability coefficients of components of RC bars considering the overall interactions of compression, shear, flexure and torsion. The coefficient of component vulnerability is reflected in the degree of damage that the components suffered under external loading when the internal force redistributes within a certain range. And these coefficients make it possible to measure the extent of the component damage.According to the theory of the vulnerability coefficients of components proposed in this paper, as well as the importance coefficients of components in existing researches, the new definition of robustness and the robustness coefficients of structure which evaluate the robustness of the structure are proposed. The robustness coefficients proposed in this paper corresponds to the mainstream meaning of robustness, which is a good robustness of the structure ensures the disproportionate damage from the initial one will not occur even under the case of some elements disables. And the theory of robustness in this paper can be applied to RC frames as well. Since the theory is compatible, other methods to evaluate the vulnerability or importance of components from different point of view, or other measure methods of robustness that are based on the vulnerability coefficients and the importance ones can be also carried out.At last, planar frame models of common RC frame school buildings were analyzed in the theory of robustness; and several problems in the structural design of school buildings are pointed out. Some modified design opinions are brought forward. Compared the pushover analysis results and robustness coefficients of the initial model and modified ones, it is indicated that the suggestions effectively improve the performance of anti-collapse.