Ductile structure design method based on joint staged locking

Abstract

The invention provides a ductile structure design method based on joint staged locking. Structural design is based on staged locking of structural connection joints, and staged locking of the connection joints refers to gradual locking of joint connection from hinged connection to semi-rigid connection to rigid connection; before the connection joints are completely locked to form a complete structural system, the self-weight or decoration load of a floor system is completely loaded to frame beams; the rotational rigidity of semi-rigid connection is smaller than a threshold value; and by the adoption of the scheme, compared with a traditional method that beam ends bear most of the self-weight bending moment, the method reduces the self-weight bending moment of the beam ends to a certain extent, improves the force bearing performance of the beam ends, and enables the beam ends to be capable of better bearing the function of ductile energy consumption under an earthquake.

Description

technical field [0001] The invention relates to the field of construction engineering, in particular to a ductile structure design method based on node locking in stages. Background technique [0002] The current structural design is based on the following model: first, the joints between the structural components are locked or poured into shape, the joints become rigid joints, and the structure forms a complete system, and then the load is applied. For example, in the steel frame structure, the beam-column joints are rigidly connected to form the structural system first, and then the floor is loaded; while in the concrete structure, the scaffolding is set up to support the formwork, and then the column beam slab is poured, and the formwork support is removed after the structure reaches the design strength. When the column-beam-slab becomes a complete structural system, then the load is added; the above two modes are the modes in which the structural system of rigid joints i...

AI Technical Summary

Problems solved by technology

[0003] One of the problems brought about by the above-mentioned current design mode of loading after rigid connection is that the bending moment distributed at the beam end due to the rigid connection of the node is much larger than that at the mid-span, the beam section needs to be made larger, and the beam end needs to be made larger Only strong ones can meet the needs, which in turn makes it difficult to realize the anti-seismic concept of "strong columns and weak beams". The ductility of the structure is low, and the safety of the structure is low when the earthquake comes.

For the steel structure system, the current model beam needs a larger cross-section, and the beam-column joints need to be designed to be stronger than the ductile structure, and the joints are too strong to cause welding damage to the columns. In previous earthquake disasters, the steel columns were damaged The part with more damage is the node part of the beam and column. Correspondingly, in these cases, the steel beam did not play its role of ductility and energy dissipation well.

For concrete structures, there are more and denser reinforcement at the beam end, which easily leads to less dense joint domain and lower strength, which affects the ductility of the joint. The large number of beam end reinforcement is also the main reason why the beam-hinge mechanism is difficult to appear in the concrete frame structure. In earthquakes, column yield failure is often the result, and it is difficult to realize the ductile frame mechanism of beam end yield energy dissipation expected by our design

[0004] The second problem brought about by the above-mentioned current design mode of reloading after just connecting the nodes is the influence of the beam end bending moment on the connected columns. However, due to the unequal spans of beams, unequal loads, and unequal compression deformation of columns, etc., It will lead to unbalanced bending moment of the beam ends on both sides of the column and be attached to the column, increasing the bending moment of the column, which will lead to unfavorable work of the column and the economical efficiency of the system is not good

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