Analysis of case study presenting ground anchor load-transfer response in shale stratum

This paper presents the analysis of the instrumentation and monitoring of ground anchors for a landslide stabilization system located at the State Route 82 Bridge, near Brecksville, Summit County, Ohio (SUM 82). The stabilization system consisted of two tieback walls. Site conditions and design aspects are considered; also, the construction sequence is presented. Field performance data were collected during and after construction, representing a total monitoring period of about 340 days. Load transfer was studied based on strain gage measurements along the bonded length of the anchors. Load variation during preproduction and performance tests of the anchors is described and discussed. A numerical procedure is presented to evaluate the anchor load–deformation characteristics based on the t-z approach. Two strain-softening load-transfer functions were used at the interface between the bonded length of the anchors and the rock. The analysis shows that the prediction of the load–displacement curve for each anchor is more influenced by the selected ultimate side frictional resistance along the anchor–rock interface than the shear stiffness of the interface. This study concludes that it is critical that peak and residual load characteristics be included in the load-transfer models for anchors installed in rock.