Method for calculating crack width of reinforcing steel bar-steel fiber concrete shield duct piece

Abstract

The invention discloses a method for calculating the crack width of a reinforcing steel bar-steel fiber concrete shield duct piece. The method comprises: S1, carrying out loading testing on a reinforcing steel bar-steel fiber concrete beam; S2, carrying out calculation based on loading test data to obtain a crack width influence coefficient; S3, determining a corresponding pre-crack width according to the crack width influence coefficient; S4, carrying out calculation based on loading test data to obtain a tensile strength influence coefficient; S5, determining a corresponding crack bending moment based on the tensile strength influence coefficient; and S6, carrying out correction based on the calculation formula of the pre-crack width and acquiring a corresponding crack width according tothe corrected calculation formula. The calculation result is more accurate and close to the actually measured result. The method is easy to apply directly in the engineering practice and the reference is provided for the tunnel duct piece design. The method has the important engineering application value. An assessment basis is provided for evaluating the durability of the high-strength reinforcing steel bar-steel fiber concrete shield duct piece.

Description

technical field [0001] The invention belongs to the technical field of calculating the crack width of concrete members, and in particular relates to a calculation method for the crack width of a steel bar-steel fiber concrete shield segment. Background technique [0002] Rebar-steel fiber concrete is prepared by mixing a certain amount of short steel fibers randomly distributed in the ordinary reinforced concrete matrix, which greatly improves the ductility and toughness of the concrete, and prevents the development of micro-cracks inside the concrete and the formation of macro-cracks. Expansion, so that the damage of concrete has certain ductility characteristics, and its durability and fatigue resistance have also been greatly improved. [0003] With the wide application of tunnel shield technology, the problem of segment cracking has gradually emerged. The shield segment needs to bear the uncertain load in the process of manufacturing, handling and installation and the h...

AI Technical Summary

Problems solved by technology

The traditional method of calculating the cracking moment of steel fiber reinforced concrete is relatively conservative, and only for members with strength grades of CF20~CF40, which is not satisfied with engineering practice.

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