Pullout Tests Using Steel Grid Reinforcements with Low‐Quality Backfill

Abstract

Both laboratory and field pullout tests are conducted using steel grid reinforcements with cohesive-frictional backfill soils. The laboratory pullout tests are performed using a large-scale pullout apparatus designed especially for this study. The field pullout tests are performed on the dummy welded-wire reinforcements embedded in a full-scale reinforced test wall/embankment system that utilize three different locally available, low-quality, cohesive-frictional backfill soilds, namely, clayey sand, lateritic soil, and weathered clay, in the three sections along its length. It is observed that the magnitudes of the mobilized field pullout resistances as well as the strains induced in the reinforcing elements are strongly influenced by the response of the wall/embankment system to the subsoil movements and the resulting arching effects due to the presence of the inextensible reinforcements. Meanwhile, the laboratory pullout test results generally seem to provide a conservative approximation of the field pullout resistances of the grid reinforcements in cohesive-frictional backfills. Using the finite element method to model the laboratory pullout tests, the analytical results are observed to agree fairly well with the experimental results.