Seismic performances of precast segmental column under bidirectional earthquake motions: Shake table test and numerical evaluation

Precast segmental concrete column, as one of the prefabricated structures used to accelerate the construction speed in the urban areas with heavy traffic, has been more and more widely used recently. Current applications of such structures are mainly limited to the low seismicity areas due to the lack of knowledge on its seismic performances. Recently, extensive research efforts have been made to understand the force-displacement relationship of such columns under quasi-static cyclic loading through experimental and numerical investigations. The behaviours of the column under real dynamic earthquake motions were, however, rarely investigated. Moreover, only the uniaxial motion was considered in the limited shake table tests of such columns despite earthquake excitations have three components in reality. This study carries out shake table tests on the seismic performances of precast segmental concrete column, and bidirectional earthquake motions were used as inputs. For comparison, the behaviours of the traditional cast-in-situ monolithic column were also experimentally investigated and compared with the segmental column. Interestingly, the experimental results showed that significant twisting occurred to the segmental column under the bidirectional earthquake motions. To prevent the adverse twisting response, shear keys between the segments are proposed. The effectiveness of the proposed method is demonstrated through numerical simulations after the model is validated by the experimental results.