Analysis of anchorage performance on new tension-compression anchorⅡ: model test

The new tension-compression composite anchor (TC-anchor) is developed to overcome the shortcomings of the traditional tensile-type anchor (T-anchor) and pressure-type anchor (C-anchor), such as stress concentration, insufficient bonding strength between anchorage body and soil mass, and low uplift bearing capacity. The ultimate uplift bearing capacity and anchorage performance are analyzed comparatively based on the model tests for T-anchor, C-anchor and TC-anchor. The results show that, in contrast with T-anchor, the ultimate uplift bearing capacities of TC-anchor significantly increase by 79% and 161% respectively for the tension-compression anchorage length ratios (TCAL-ratio) of 1:2 and 2:1. The TC-anchor has better displacement ductility and deformation resistivity, and its residual uplift bearing capacity increases significantly. The maximum ratios of the residual uplift bearing capacity to the ultimate one (RU-ratio) of T-anchor and C-anchor are both not more than 0.40, with the average values of 0.292 and 0.259 for relative out deformation of anchor head ξ_s=2.5%. The tension and compression anchorage segments of TC-anchor with TCAL-ratio of 2:1 have stronger coordination-bearing capacity. When the TC-anchor is closed to failure, the bonding strength between grouting body and concrete failure plays sufficiently. So the ultimate uplift bearing capacity of TC-ancor with TCAL-ratio 2:1 is higher.