Blast response of cantilever retaining wall: Modes of wall movement

For the past few decades, there has been an increase in awareness regarding the safety of highway bridges from blast loads. Since abutments/Retaining walls (RWs) are portions of bridges, investigating abutments/RW or RW behaviour under blast loads is important. As there have not been any studies investigating the dynamic response of retaining walls due to blast loading, an experimental study was conducted to examine the influence of blast loads on the dynamic behaviour of reinforced concrete retaining wall (RCRW) with sand as a backfill material. A shock tube was used to generate blast loads on the soil-RW model. The influence of the relative density, backfill saturation, blast load intensity, and traffic load equivalent surcharge on the blast behaviour of RCRW with sand backfill was studied. The results showed that the modes of wall movement were affected by the backfill relative density, blast load intensities, and degree of saturation. Under the same load conditions, an increase in the wall movement was noticed in loose backfill, and a translation response mode was evident in this condition. A relationship between wall relative movements and mobilized earth pressure coefficients was determined. The mobilized passive resistance of the RW backfill induced by blast load was used to determine the force--displacement relationship. Acceleration time histories for RW/backfill were found for all conditions. The findings of this research will help to properly evaluate and design bridges' abutment and to develop resilient transportation infrastructure systems.