复合配筋预应力混凝土管桩抗弯性能试验和数值分析

开发研制了复合配筋(GFRP筋)预应力混凝土管桩(以下简称PRC-G桩),并进行了抗弯性能的现场抗弯试验和数值分析。试验研究结果表明,GFRP筋可以明显改善常规管桩的抗弯性能,其开裂荷载和极限荷载均有显著的提高,破坏时PRC-G桩均是受压区混凝土破碎而PRC桩的预应力筋被拉断;数值分析结果表明,PRC桩破坏时,预应力钢筋达到屈服强度1 420 MPa,PRC桩受压区混凝土未达到标准抗压强度,桩身未被破坏;PRC-G桩破坏时,受压区混凝土最大压应力为52.03 MPa,受压区混凝土破碎,管桩破坏。抗弯数值模拟和抗弯试验的结果表明,两者的荷载-挠度曲线的规律基本一致。研究成果可为复合配筋(GFRP筋)预应力混凝土管桩在工程中的推广应用提供理论依据。

Experimental Study and Numerical Analysis on Bending Capability of Compositely Reinforced (GFRP) Prestressed Concrete Pipe Pile

The flexural capacity of compositely reinforced (GFRP) pre-stressed concrete pipe pile are studied through test and numerical analysis. Glass fiber reinforced polymer (GFRP) has some properties such as lightweight, high tensile strength and strong in corrosion resistance, which can be exerted the high strength properties through joining with concrete by the common power mechanisms. The bending test shows that GFRP evidently improves the flexural properties, the cracking load and the ultimate load of PRC-G piles all increase to different extent. Concrete compression zone of PRC-G piles is broken and tendons of PRC piles are pulled off. In addition, based on the data from numerical analysis, the pre-stressed reinforcement reaches the yield strength (1 420 MPa) when PRC piles are damaged, and the compressive strength of concrete does not meet the standard compressive strength, while the pile body is not damaged. However, the maximum compressive stress of compressive concrete zone is 52.03 MPa while the pile is damaged. The results of bending numerical simulation and test show that the load deflection curves are consistent. Meanwhile, research results can provide the theory basis for the popularization and application in engineering of composite reinforcement (GFRP) pre-stressed concrete pipe pile.