Behaviour of a double reinforced concrete wall under impact of a soft missile

EDF is required to design some structures, in French NPP, in order to withstand plane impacts (safety barriers). However, in the case of some building configurations, the safety barrier is protected by another structure which has a different function. The existence of this double-walled protection leads to the possibility of designing the safety barrier for less severe impacts, taking into account the loss of energy of the missile. Experiments which consisted of projecting steel pipes against reinforced concrete slabs were carried out. During the same time, in order to calculate the residual speed and energy of a soft missile after passing through a reinforced concrete wall, EDF has developed a computer program. Comparisons between tests and computer results are pointed out. Applications of this code (e.g. for aircraft impacts) are outlined and further developments are indicated. (orig./HP)