FLEXIBLE AND RIGID FACED MSE WALLS SUBJECT TO BLASTING

Mechanical stabilized earth (MSE) walls are often used in military and civilian applications to protect personnel and property from accidental detonation of stored explosives, munitions, and ammunition plants. The advantages of geosynthetics reinforced soil and Reinforced Earth (registered trademark) (RE) structures lie in their cost-effectiveness, rapid construction, and minimization of occupied ground area and high tolerance of differential settlements. Concrete faced RE structure has very presentable concrete facing and was found to be able to withstand base shaking arising from earthquake. For protection against blast, geosynthetics reinforced soil walls are able to impede the propagation of a blast at ground level and absorb high levels of energy due to their tolerance for deformation before collapse. In using geosynthetics as facings and reinforcements, the reinforced soil structures not only can absorb fragments from cased weapon explosion, but they also do not suffer brittle fracture like concrete after blasting. Hence they minimize the dispersal of debris and are resistant to multiple blasting. A geosynthetics reinforced soil wall and a RE wall with precast concrete facings were constructed and subjected to multiple blasts and their extent of damage was recorded and studied. After a series of blasts, the concrete facings in front of the RE wall collapsed and the soil mass slid down to the front. There were obvious pullout failures of the metal reinforcement strips as well as tension failure at the joints of the panel facings and reinforcements. However, the geosynthetics facing of the reinforced soil wall only suffered superficial damage due to high temperature and direct impact of fragments. Acknowledging the differences in failure modes of reinforced soil and RE walls under blast loading, it was obvious that geosynthetics reinforced soil walls with flexible geosynthetics wrapped around type of facing can be effectively used for blast resistant soil structures in military applications.