Study on Flexural Bearing Capacity of Ultra-high Strength Concrete Mixed Reinforced Pipe Pile
In order to study the flexural bearing capacity of ultra-high strength concrete(C105)mixed reinforced pipe piles,the flexural performance test of six concrete pipe piles was carried out,and the influence of non-prestressed reinforcement configuration on the flexural performance of ultra-high strength concrete pipe piles was analyzed.The test results show that both PRC pipe pile and PHC pipe pile specimens show flexural failure,and the former shows more obvious ductile failure state when it is destroyed.The configuration of non-prestressed steel bars improves the distribution of cracks in the pipe pile.The number of cracks increases with the increase of the reinforcement ratio of non-prestressed steel bars,and the average crack spacing decreases gradually.The maximum crack width under the same load also decreases with the increase of non-prestressed reinforcement ratio.Compared with the test results,the calculated value of the flexural bearing capacity of the curr-ent atlas is small,and the safety reserve is too high for the PRC pipe pile with good ductility.And the relevant calculation parameters are mostly empirical parameters,lacking a certain theoretical basis.Therefore,considering the influence of the resultant force of Cl05 concrete and prestressed reinforcement in tension zone on the bending capacity of pipe piles,the formula of bending capacity of the atlas is modified based on the relevant calculation assumptions.The calculation results show that the modified calculation formula is 5%~10%higher than the calculation results of the curr-ent atlas.