Stiffness degradation process analysis of multi-ribbed composite wall

Multi-ribbed composite wall is the main anti-lateral force component in multi-ribbed slab structure system and the law of its stiffness degradation under load is one of the fundamental problems about seismic performance of multi-ribbed slab structures. Low-cyclic reversed loading tests were conducted on composite wall samples with the ratio of 1:2, in which the characteristic point stiffness and the law of their stiffness degradation process from loading to failure were studied, and the effect of main influencing factors such as axial compression ratio on the wall stiffness degeneration was analyzed. The results show that with the increase of axial compression ratio, the decrease of the shear span ratio, outside frame section and its reinforcement ratio, rib column(beam) quantity, the speed of stiffness degradation increased. Otherwise it decreased. The stiffness degradation formula and degradation coefficients in different deformation stages were presented and methods to delay stiffness degradation with construction technique improvement and fibers as stuffing materials were also discussed. The study has provided reference for the application of multi-ribbed slab structure.