上锚式灌浆波纹管连接预制墩柱拟静力试验研究OA北大核心CSTPCDEI

An innovative precast assembled pier column with an upper-anchored grouted metal corrugated ducts connection is a structural configuration where the grouted corrugated duct is embedded in a locally enlarged cross-section pier and connected to the bridge pile cap.This construction method offers convenience and economic efficiency.The seismic performance of precast piers with the upper-anchored grouted corrugated metal ducts connection was investigated by quasi-static tests on two precast piers of different pier heights and one cast-in-place concrete specimen.The scaled-down ratio for all three specimens was 1:2.5.During the tests,each specimen was subjected to constant axial compression and horizontal loads were applied with displacement control until failure.The crack damage state of the specimens was observed,and the seismic performance was analyzed in terms of hysteresis characteristics,skeleton curves,ductility,energy dissipation capacity and residual deformation.The research results indicate that both the upper-anchored specimens and the cast-in-place specimens form effective plastic hinges;however,there are significant differences in the formation position of plastic hinges and the characteristics of ultimate failure.Plastic hinges are formed above the section enlargement segment in the upper-anchored specimens,while the cast-in-place specimen form plastic hinges at the bottom of the pier.At the ultimate failure stage,the main reinforcement in the upper-anchored specimens does not break,whereas the main reinforcement in the cast-in-place specimen exhibits pullout.The yield load and ultimate load of the upper-anchored specimens are 123.8%and 113.7%of those of cast-in-place specimen's values,respectively,indicating a close similarity in load-bearing capacities.However,the ductility of the upper-anchored specimens is weaker than that of the cast-in-place specimen,with displacement ductility and curvature ductility being 75.9%and 92.3%of the cast-in-place specimen's values,respectively.The pier height has a significant influence on the failure mode and characteristics of the upper-anchored grouted ducts connection specimens.The low-height specimen exhibits more shear failure characteristics,poorer ductility,and a curvature ductility of only 38%compared to the high-height specimen.The low-height specimen also has weaker energy dissipation capacity,with cumulative hysteresis energy dissipation being only 62.2%of that of the high-height specimen.The study demonstrates that the seismic performance of precast pier with upper-anchored grouted metal corrugated ducts connection is similar to cast-in-place pier,demonstrating significant pratical value and engineering significance.