Development of seismic resistant glass partitions

The condition of undamaged or lightly damaged internal partitions after seismic events is of utmost importance for at least three building performance levels: i) life safety, ii) operational and iii) damage. Indeed, victims may be caused by the weight of falling partitions, the obstruction of the ways out and the dust released by some (e.g. brick) partitions. Cracks and dislocations of internal partitions, which can be also caused by frequent earthquakes, may lead to the downtime of the building hosting the partitions; downtime cannot be accepted in case of strategic buildings and may lead to large losses in case of industrial and commercial buildings. Large economic losses are also related to the damage itself of the partitions. Consequently, modern seismic codes pay attention to the protection of these nonstructural elements, imposing their seismic qualification and providing strength verifications, based on accelerations, and displacement verifications, based on story drifts. Their protection also conditions the structural design: seismic codes link the stiffness of the structure to the damage of the partitions and the structural strength distribution to the possible irregular distribution of the partitions. Contemporaneous architectural choices are leading to a large increase of the use of glass partitions, for both aesthetic and functional reasons: sound and thermic compartmentations should not be also visual barriers. Glass partitions are more and more used in offices, belonging also to strategic buildings. On the other hand, fragility, stiffness and weight of the glass sheets are features increasing the seismic vulnerability of this partition type. Consequently, the development of glass partitions, remaining operational after strong earthquakes, is an urgent need, which cannot be reached without a strong cooperation between research and industry. Indeed, glass partitions are sophisticated industrial products, characterized by a detailed and expensive manufacture of glass and either steel or aluminum. The paper shows the development of glass partitions which remain operational after very severe earthquakes, i.e. under large accelerations and story drifts, as shown by shake table tests. Four types of partitions are developed, fully glass, glass partition with a glass door, mixed glass and steel and, finally, mixed glass and wood. It is confirmed that, as already known, simple details may largely increase the seismic performance of nonstructural elements.