Analysis On Seismic Performance Of High Ductility Of Steel Bar For Prestressed High Strength Concrete Pile

Prestressed high strength concrete pile(PHC pile)has been widely used in engineering construction, because PHC piles have the advantage of high bearing capacity of a single pile and high speed of construction. However, the earthquake resistance capability of the pile is insufficient, according to domestic and external earthquake damage investigation, which greatly limits the use of PHC piles. Therefore,it is necessary to adopt the proper improvement measures to improve the seismic performance of PHC piles. High ductility of steel bar for prestressed high strength concrete pile(HDPHC pile), is improved from the original PHC pile. PHC pile’s prestressed steel bars are replaced by the same number of high ductility steel bars.The HDPHC piles model was analyzed by using the finite element software ANSYS, evaluate the seisimc performance of HDPHC pile under cyclic loading.Firstly,The finite element model of PHC pile was established by using ANSYS.And the quasi-static analysis method was applied for the numerical analysis. The analysis results were compared with the experimental result of PHC pile test to verify the effectiveness of the model;Secondly, the HDPHC pile model was established based on ANSYS by replacing PHC pile model’s the prestressed steel bars with the same number of high ductility of steel bars. The same analysis method was applied for the numerical analysis to study the seismic performance of HDPHC piles;Finally, For further study, volume stirrup rate, percentage of the prestressed reinforcement,effective pre-stress of concrete and strength grade of concrete was considered to study this factors’ effect on the seismic performance of HDPHC pile.Through analysis, the following conclusions can be obtained. HDPHC pile hysteretic curve than the PHC pile hysteretic curve more full,shows its better seismic performance;compared with the skeleton curve of PHC pile,HDPHC pile skeleton curve is smooth and has obvious decline period,explain the ductility of HDPHC pile has been very good improvement;the surrounded by HDPHC pile with each cycle the hysteresis loop area larger,show its better energy dissipation capacity,has the very good to reduce the seismic response and reduce the ability of earthquake damage;change the stirrup ratio can improve the seismic performance of HDPHC pile,high ductility of steel bar diameter on the seismic performance of pile increasessignificantly improved the effective prestressing force concrete,the increase can not improve the seismic performance of pile.