Experiments of cast-in anchors under simulated seismic loads

This paper presents a series of tests of cast-in anchors subjected to simulated seismic loads, including 19 shear tests and 17 tension tests. The specimens were subjected to both monotonic and displacement-controlled quasi-static cyclic loading. The anchors under cyclic loading showed strength degradation, especially towards the later stages of loading with relatively large displacement levels. Anchors controlled by steel fracture in shear had significant strength reduction, which was attributed to bending in anchor shafts caused by progressive concrete damage. The cyclic tests were added to a database of 114 tests (11 from this study) in shear and 22 tests (8 from this study) in tension. These available tests of cast-in anchors indicated that the existing seismic reduction factor of 0.75 in ACI 318 failure is conservative for concrete breakout failure mode. Meanwhile, a capacity reduction factor for anchors with steel failure in shear seems necessary, and a reduction factor of 0.75 is suggested though further study is needed to better understand the related behavior.

Automated summary

This study conducted a series of tests on cast-in anchors subjected to simulated seismic loads, finding strength degradation in anchors under cyclic loading, especially with large displacement levels. Anchors controlled by steel fracture in shear showed significant strength reduction, indicating the need for further research to better understand the behavior.