Prestress concrete bridge corrosion fatigue life prediction method

Abstract

The invention discloses a prestress concrete bridge corrosion fatigue life prediction method. A stress of a steel strand is divided into three parts as follows: a tensile stress caused by a residual effective pre-applied force, an elastic stress caused by a fatigue load and a stress caused by plastic deformation of concrete in a pressed region. The structural residual pre-applied force is obtainedby predicting a rust corrosion level of the steel strand; a stress concentration factor is introduced to consider stress concentration influence caused by pitting corrosion, and a steel strand elastic stress growth model under the combined action of corrosion and fatigue is proposed; section loss of the steel strand is used as a fatigue damage parameter, degeneration of an elasticity modulus of the concrete after fatigue is considered, and a steel strand plastic stress growth model is established; and the failure criterion of the concrete, the steel strand and a common reinforcement is determined, and a full set of prestress concrete bridge life analysis method under the action of a corrosion environment and the fatigue load is formed. The prediction method disclosed by the invention is reasonable and high in applicability, and can provide support for safety assessment of an in-service prestress concrete bridge.

Description

technical field [0001] The invention relates to the field of safety assessment of bridges in service, in particular to a method for predicting the corrosion fatigue life of prestressed concrete bridges. Background technique [0002] Prestressed concrete bridges have strong spanning ability and account for a large proportion of highway bridges in my country. In recent years, the durability problems of such bridges have gradually emerged. For post-tensioned prestressed concrete beams, the construction technology requires that the prestressed tendons need to be grouted after the prestressed tendons are stretched. However, in the post-tensioned prestressed concrete bridges built in the early stage, due to construction defects, bleeding and other reasons, the problem of insufficient grouting in the prestressed concrete beam channel is more common. Insufficient grouting will accelerate the intrusion of corrosion ions and cause corrosion of steel strands, reducing the synergy bet...

AI Technical Summary

Problems solved by technology

After the steel strands in post-tensioned prestressed concrete bridges are corroded, the stress state is more complex, and the determination of fatigue damage parameters is more difficult

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