Deformation of Geogrid-Reinforced Segmental Retaining Wall due to Insufficient Compaction of Loess Backfill: Case Study in Shaanxi Province, China

Abstract

The distress history of a geogrid-reinforced segmental retaining wall (GR-SRW) that was constructed as a highway shoulder, June 2014, using loess backfill in Shaanxi Province, China, is presented. A narrow, arc-shaped pavement crack propagating toward the wall and a vertical open gap between the cover plate and coping were found in September 2014. Improper diagnosis and treatment caused the crack and gap to worsen until June 2016. Consultation, field observations, measurement, drilling, laboratory tests, and internal stability analyses were executed immediately to determine the causes of the distress. Consultation and field observation were executed to obtain the GR-SRW development on November 5th, 2018. The insufficient and differential compaction of the loess backfill likely caused the distress initially found. Water infiltration, fine-grained loess backfill use, and improper diagnosis and treatment worsened the GR-SRW distress from June 2014 to November 2018. Preliminary repair suggestions, including a prestressed anchoring wallboard retaining wall, upswept drainpipes, rammed soil-cement or compacted soil-lime columns, and rebuilding the existing pavement layers, were provided. Lessons learned provide a reference for future construction.