Tests of small scale buried structures under surface impact loading

The tests described are part of research into the response of a structure with a reinforced concrete roof, embedded in a shallow depth of burial to an external surface impact. The experimental system consist of a small scale Plexiglas cylinder embedded under a shallow depth of dry Ottawa sand, supporting a reinforced micro-concrete roof and sand backfill subjected to a mechanical impact. Measurements were acquired of the roof motion (velocity and displacement), and of the pressure over the roof and in the free field. This technique combines the convenience of a laboratory testing with the capability to conduct precise measurements of the system important variables. The experimental results showed a relation between the loading on the buried roof and its motion, thus indicating the occurrence of phenomena that are caused by the soil-structure interaction. The value of this test is demonstrated by comparison to observations from a soil-structure reference system with larger dimensions, different geometry, and higher external load, that indicate the occurrence of phenomena, similar to those that were indicated in the small scale tests. -Authors