Experimental study and theoretical analysis of axial compression bearing capacity of damaged timber columns

The existing timber structures of ancient buildings are mostly damaged by insect infestation and decay, which seriously affect the stability and safety. To obtain the bearing capacity of damaged timber columns, this study conducted axial compression tests on seven specimens. Three sets of numerical models with different damaged areas, lengths and positions were established, and then the bearing capacity calculation model of the damaged timber columns was derived. The results show that: (1) As the damage area increases or the damage location approaches the mid-height of the column, the failure mode transitions from compressive fiber crushing to tensile fiber fracture. (2) When the ratio of the damaged area was 13.13%−70.20%, the bearing capacity decreased by 34.14%−95.02% compared with the intact timber column. When the damaged length increased from 200 mm to 1400 mm, the bearing capacity decreased by 62.75%−69.73%. When the damaged position was in the middle of the column, the bearing capacity was the lowest at 146.14 kN. (3) The damaged degradation model and theoretical calculation model of axial compression bearing capacity of damaged timber column were developed. These conclusions provide theoretical basis for the quantitative evaluation and conservation of damaged timber structures.