Influence of Axial Compression Ratio on the Seismic Performance of Precast Columns with Grouted Sleeve Connections

Substantial attention has been paid to precast structures due to their obvious advantages. While precast members connected by grouted sleeves are used in seismic regions, studies on the seismic performance of precast column under large axial compression ratio are few, especially in underground structures. In this paper, three full-scale precast columns were designed and tested under axial compression ratios of 0.2, 0.5, and 0.85. Additionally, three monolithic cast-in-place columns with identical details served as a control. The main objectives of this study are to study the influence of the axial compression ratio on the global mechanical behavior of precast columns subjected to low-cyclic reversed horizontal loads, and to discover the internal force distribution and reach the appropriate axial compression ratio for precast columns. The test results are: (1) Precast columns were capable of matching the deformation and lateral strength of monolithic connections under the same compression ratio, while they were affected significantly by the axial compression ratio. (2) The plastic hinge location of precast columns shifted above the grouted sleeve region. It is found that good ductility can be exhibited compared with conventional cast-in-place column. (3) An effective measure to relieve uncoordinated stiffness along the height of the column was introduced. (4) Based on strength and deformation with the same axial compression ratio, the appropriate axial compression ratio was achieved for precast columns and the relationship of spliced-bar strain ratio and axial compression ratio was presented.

Automated summary

This study focused on the influence of axial compression ratio on the global mechanical behavior of precast columns under low-cyclic reversed horizontal loads, finding significant effects of the axial compression ratio on precast columns and good ductility compared with conventional cast-in-place columns. Additionally, an effective measure was introduced to relieve uncoordinated stiffness along the height of the column.