Building reinforcing method, material and structure

Abstract

A high-ductility material or a high-ductility covering material is disposed on the outer circumferential surface of a member, such as a column, of a structure so as to confine expansion of apparent volume accompanying rupture of the member, to thereby control rupture of the member. The high-ductility material is a fibrous or rubber sheet material. The high-ductility material is disposed in such a manner as to surround the member. Alternatively, the high-ductility material is spirally wound or rolled on the member.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a continuation application of U.S. patent application Ser. No. 10 / 089,108 filed Mar. 26, 2002.TECHNICAL FIELD [0002] The present invention relates to a method, configuration, and material for reinforcing a structure for preventing serious damage to people and property in and around the structure, which would otherwise result from collapse of the structure, even after members (structural components, such as beams, girders, slabs, walls, and columns) of buildings and infrastructures (hereinafter generically called a “structure”) are visibly deformed due to rupture thereof caused by an abruptly imposed external force, such as a seismic force or wind force or an excessive load accompanying demolition, or caused by deficiency in yield strength stemming from deterioration. BACKGROUND ART [0003] An external force imposed abruptly by earthquake or the like, or deficiency in yield strength stemming from deterioration has repea...

AI Technical Summary

Benefits of technology

This approach allows for efficient and cost-effective reinforcement of structures, maintaining stability and preventing catastrophic collapse even after initial deformation, while reducing material and labor costs, and enabling rapid implementation during emergencies.

Problems solved by technology

An external force imposed abruptly by earthquake or the like, or deficiency in yield strength stemming from deterioration has repeatedly caused an abrupt collapse of a structure, resulting in damage to lives and property.

Component members of a structure are ruptured due to excessive load or deficiency in yield strength.

Resultant deterioration of stability of the overall fabric of the structure causes significant deformation to the shape of the structure, thereby causing a reduction in the internal space of the structure; i.e., structural collapse.

In many cases of collapse of a building, floors fall down in a heap, like a stack of pancakes, or collapse.

In many cases of collapse of an elevated bridge, bridge piers are ruptured, resulting in collapse of the bridge.

When an external force in excess of the assumed level is imposed on a member, the member is ruptured, resulting in a failure to ensure the overall stability of a structure.

Thus, in many cases, the conventional measures involve excessively high cost.

Hiring such skilled workers is difficult nowadays.

Accordingly, even when an existing structure is known to involve a great risk of collapse due to deterioration, or because the structure is designed according to old standard or has been damaged by an external force imposed abruptly by earthquake or the like, in many cases, reinforcement of the structure has been unfeasible, for economic and physical reasons.

In a certain case, after occurrence of disaster, such as earthquake, when an examiner(s) entered a damaged structure in order to tentatively evaluate the degree of collapse risk, an aftershock caused the structure to collapse, with the result that the examiner(s) were killed or injured.

In another case, when dwellers and users entered a structure which was judged safe in view of minor damage, an aftershock caused the structure to collapse, resulting in heavy casualties.

As shown in FIG. 22, reinforcement enhances strength and / or toughness; however, there is no guarantee that the member can bear an upper load after a toughness limit is exceeded.

However, in the case of deformation in excess of the range, a mechanism for bearing a load is lost, resulting in rapid progress of deformation.

As a result, collapse of the structure becomes unavoidable.

However, the shearing stress S causes a shear fracture of the column 1 with a resultant impairment in rigidity, organ excessive axial force causes rupture or dislocation of a tie hoop(s) with a resultant failure to bear the circumferential tensile force T. As a result, as shown in FIG. 24(b), deformation progresses rapidly, followed by complete collapse as shown in FIG. 24(c).

In this manner, the aforementioned pancake-like destruction phenomenon unavoidably occurs.

In the case where a large number of structures must be reinforced immediately after occurrence of an abrupt disaster, such as earthquake, or due to revision of the seismic standard, the conventional measures described above are unsuitable for promptly coping with the situation so as to secure safety.

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