Blast induced lateral earth pressures on retaining structures with sand backfill

An experimental study was conducted to investigate the effects of blast loads on the behaviour of reinforced concrete retaining wall (RCRW) with sand as a backfill material. The soil-RW model was subjected to a simulated blast load using a shock tube. The influence of the backfill relative density, backfill saturation, blast load intensity, and live load surcharge on the behaviour of RCRW with sand backfill was studied. Based on the results, it was noted that the maximum dynamic earth pressures were recorded at a time greater than the positive period regardless of the backfill condition. The total earth pressure distribution along the height of the wall showed that the magnitude of total earth pressure for loose and medium backfill at the mid-height of the wall slightly exceeded the dense backfill. In addition, the lateral earth pressures increased with the increase of the blast load intensities. Relationships between the dynamic earth pressure coefficient ( Δ K b d ) and accelerations of the wall and the backfill were determined. The maximum dynamic resistance function was reached when high-intensity pressure is applied. Yield was not reached, and intensities of the shots were below the design capacity of the section. The findings of this research will provide valuable information that can be used to evaluate the vulnerability of transportation structures to surface blast events and the development of guidelines for their design.