Abstract: Saturated sand foundation may be liquefied under explosive load. Structures on the foundation will suffer a dual influence of explosive load and sand liquefaction, which causes uneven settlement and destructive deformation. Based on a large-scale field test of liquefied foundation induced by embedded blast, the dynamic response of the shallow-buried reinforced concrete (RC) structures subjected to explosion and its deformations after liquefaction are examined. It is indicated that, obvious uneven settlement of the RC structure occurs; and the maximum settlement reaches 10% of the height of the RC structure; and differential settlement reaches 1/5 of the maximum settlement. The settlement comes to be stable in 15 hours after the explosion. There is no obvious crack appearing on the surface of the structure; and the dynamic tensile and compressive strains are both under 400 ??, which would not cause significant damage to the structure. The acceleration peak of the column is larger than that of the girder; however, the time required for the dynamic stability of column is shorter than that of the girder, i.e. column suffers a larger instantaneous impulse and has stronger ability to resist instantaneous impulse. The results provide references for the seismic design of shallow-buried RC structures in the liquefiable soils.

Key words: blast induced liquefaction, shallow-buried reinforced concrete structures, dynamic response, settlement and deformation, in-situ test