The effect of compaction on model fabric reinforced brick faced earth retaining walls

Many theoretical and experimental studies of earth retaining walls have been concerned with backfills placed against the wall and not compacted in situ and therefore they do not represent the constructional techniques of backfilling in actual retaining walls. Compaction has sometimes been accompanied by unexpected excessive movement of the retaining structures, being the horizontal earth pressure developed by soil compaction, blamed for this. The effect of compaction was studied on walls which were built, backfilled and then surcharged. Backfilling was done in layers, each layer being carefully placed and compacted. The results of the present investigation show that for both unreinforced and reinforced earth retaining walls the behaviour on backfilling is complex and also completely different from that on surcharging. On backfilling, most of the variation of the quantities measured is due to compaction rather than to placement of the sand layers, this effect being especially evident in the wall deflection.