JPH0826585B2 - Joints for three-dimensional frames in steel structures - Google Patents

Abstract

Three types of fixed girder-pillar joints with two horizontal and vertical wind braces (22, 24) that can be assembled by means of bolts in the building yard for: 1) girders (1) and pillars (11) interrupted in the joint; 2) pillar (11) passing through the joint and interrupted girders; 3) pillar of reinforced concrete (11) with molds bearing the scaffolding and girder steel-concrete. Each type of joint consists of two characteristic parts (a) and (b) with bolted full resistance connections. The part (parts) of the joint (a) are connected near the pillar (pillars) in the workshop, and/or can be used to connect more parts of the joint (b); the parts of the joints (b) are to be welded near the joint.

Description

The present invention relates to a structural member for a building structure, in particular a joint for a metal grid frame formed by columns and beams, optionally reinforced by diagonal columns or braces. Regarding

In general, the current practice in building construction uses three types of joints. That is, a joint that connects the broken metal beams and columns, a joint that connects one metal column that extends through the joint to the broken beams, and a normal beam made of reinforced concrete. The composite columns and joints that connect to the supporting scaffolds are used.

A comparative test conducted on a model of a multi-story building shows that a frame structure with lattice braces reinforced with lattice braces is very effective in bearing seismic energy with significant structural flexibility. Is shown.

The following structural classification can be defined in terms of the degree of this flexibility, ie suppleness. Hinged structures locally braced by either diagonal bars or reinforced concrete wall cores-Full seismic frame reinforced by braces either steel or reinforced concrete-Plastic at column-beam connections It can be classified as a lattice frame structure with flexible joints using hinges.

Optionally, this last structure should be further reinforced by full seismic diagonal bars and flexible stiffening braces to further improve the overall flexibility and economy of the assembly. You can

It is known that hinge structures with steel braces or reinforced concrete braces are more economical and easier to operate than structures with rigid joints. In fact, welded joints of rigid structures and high-seismic bolt connections must obviously be operated inefficiently. Further, the bolt connection must form a through hole at a position close to the position where the bending moment is most concentrated with respect to the pillar, which is the most important structural member, thereby weakening the structure.

French patent specification FR-A-2 457 349 discloses a modular joint. The joint includes a one-piece cylindrical body adapted to receive a vertical post and having a radially extending peripheral portion formed at one end to connect the post to a horizontal beam. It is done like this. The cylindrical body is directly attached to the columns and beams by bolts, and these bolts are inserted into through holes formed in the wall of the cylindrical body. Therefore, the cylinder body is weakened at the most important places. Further, in such a conventional joint, the beam is substantially hinged to each cylindrical body by bolt connection, so that transmission of moment is deteriorated. These modular bodies are formed by a casting process, which is known to be an expensive technique and has undergone stringent non-destructive testing to screen acceptable qualities.

It is an object of the present invention to remedy the above mentioned drawbacks by providing a joint for a lattice frame structure which features a combination of rigidity and high flexibility so as to improve the overall seismic performance against seismic energy. Is.

Another object of the present invention is to provide a joint that prevents weakening of important members of the structure.

Another object of the present invention is to provide a joint which has a simple structure and can be easily mass-produced with a usual material in a specialized factory and can be manufactured at low cost. is there.

Yet another object of the present invention is to provide a joint which is quick to install, safe to assemble in a simple procedure, and which saves time and material.

If the reference numerals used in the embodiments of the present invention described later are additionally described for reference, the present invention is a joint for a building frame that connects a beam to a column and can be connected to the column. And a first member A that is connectable to horizontal and vertical bracing members that are finally provided in the frame by a hinge connection, and at least one second member B that is connectable to each beam, The first member A and at least one second member B are provided with holes and corresponding bolts for connecting them together by a sufficient resistance welded connection during final assembly of the building frame. The first member A and the at least one second member B are each connectable to the column and the beam at a mutually predetermined tilt angle that is variable, And said second member B comprises four plates 2,3,28,30, ie substantially parallel and vertically spaced apart, for transmitting bending moments from said beams to said first member A. Two substantially horizontal plates 2 and 28, which are separated from each other, and a plate 3 which is connected to the beam and which extends in the vertical direction for transmitting shear stress from the beam to the first member A. , For transmitting the torque induced by the beam to the first member A, extending vertically between the two substantially horizontally extending plates 2, 28 and connecting the plates 2, 28 Plate 30 and these four plates are connected to each other by connecting bolts through the first plate.
The second member B is connectable to the member A, and the second member B has a structural strength higher than that of the beam connected thereto.

The advantage afforded by the invention is mainly that the proposed joint provides a total transfer of stress to the column, while allowing the plastic hinge to be locally formed in the event of an earthquake.

Another advantage of the proposed joint is that it allows the bolt-on assembly of the frame in the beam to be assembled and allows the assembly from the top.

Still other features and advantages of the present invention will be readily apparent from the following detailed description in connection with the accompanying drawings of three embodiments given by way of example but not of limitation. In the drawings, FIG. 1 is a partially cutaway elevation view of a first embodiment of a joint structure according to the present invention.

2 is a plan view of the joint structure of FIG. 1 partially broken along line II-II.

3 is a plan view of the joint structure of FIG. 1 partially broken along the line III-III of FIG.

FIG. 4 is a cutaway sectional view of the detail of FIG. 3 along the line IV-IV.

FIG. 5 is a partially cutaway elevation view of the second embodiment of the joint structure according to the present invention.

6 is a plan view of the joint structure of FIG. 5 partially broken along line VI-VI.

FIG. 7 is a partially cutaway elevation view of the third embodiment of the joint structure according to the present invention.

FIG. 8 shows a partially broken seventh line along the line VIII-VIII.
The top view of the joint structure of a figure.

 9 is a cutaway sectional view of FIG. 7 taken along the line IX-IX.

Lattice frame structures incorporating joints according to the present invention include stacked and generally vertically oriented posts 11,15.
Are generally formed by being connected to a substantially horizontally oriented beam 1 which is preferably made of steel.

Referring to FIGS. 1-4, there is shown a first embodiment of a joint connecting a beam and a broken column.
This type of joint is suitable for buildings with few floors. In this case, the mechanical stress transmitted from one pillar to another pillar via a bolt connection has a small magnitude due to a narrow utilization space. This type of joint is therefore adapted for use in the construction of small buildings, and because all braces are interrupted at the joints to have a small size and weight, Suitable for manual assembly.

Referring to FIGS. 5-7, a second type of joint according to the present invention is shown. This applies especially to connecting a single column to a suspended beam. These joints can be arranged, for example, around a 12 m long post and can also be adjusted to the desired height position, which is preferably aligned with the post axis. If members inclined to the horizon are used, they can be attached to the joint by pre-welding at the factory. This type of joint is suitable for any type of structure, including multi-story buildings.

Referring to FIGS. 8-9, there is shown a third embodiment of a joint adapted for use with reinforced concrete columns and metal beams. In this, the beam cooperates with the concrete once it has hardened as well as the added bar. If the metal mold of the pillar is calculated as a bar in the casting support frame, the reinforced concrete of the pillar can be considered to be part of the joint. This kind of joint is very effective in steel frame for concrete structure in large multi-story building.

In general, it is envisaged that all joint structures described above are formed of two main parts or of members designated A and B adapted to be manually attached by bolt connections.

More specifically, the member A is adapted to be fixed to the columns 11 and 15, while the member B is adapted to be connected to the respective beams 1. The member A comprises a pair of superimposed locking plates, namely a lower plate 4 with through holes 21 and an upper plate 20 with through holes 29. Corresponding through holes 21 'and 29' are formed in the member B so that relatively large diameter bolts can be used to form a sufficient resistance welded connection. They do not form a weakened part in the corresponding mounting part. Optional through holes 17 may be formed in plates 4 and 20 to receive the hinged connection to horizontal diagonal member 22. Members A and B can be provided with openings 32 through which building equipment can pass.

In the joints of the second and third type shown in FIGS. 5-9, and also comprising a continuous column extending through the joint made of steel or reinforced concrete, The upper and lower locking plates 4 and 20 have axially aligned central apertures 23 for passing columns.
have. Locking of the main part of the member A to the pillar 15 is performed in the factory by welding means or the like. If the columns exhibit large rolling tolerances (the tolerances that occur during rolling of the element), the positioning gaps and the appropriate connecting plate 16 width dimensions can be varied.

In the case of columns made of reinforced concrete, member A is column 11
Embedded in the composite structure of. The columns 11 made of reinforced concrete are cast and formed integrally with the upper frame. The scaffold is supported by either steel beams, a prefabricated slab (not shown), a support mold 8 or, optionally, a lower diagonal brace 24. The mold 8 can be bolted to the plate 25 at the location indicated at 12. The plate 25 is welded vertically to the plates 4 and 20. By this structure, the plate 25 and the mold 8 delimit the cross-section of the column 11 of reinforced concrete, which forms the forming box.

In the case of a joint adapted for use with posts passing through the joint, the locking plates 4 and 20 are held substantially parallel and spaced apart, and are rigidly stiffened to each other by a spacer plate 5. Be connected. The spacer plates are welded at the top and bottom to these locking plates to form a unitary structure. Such a spacer plate 5 is an opening for passing equipment.
32 and can be connected to member B by an interconnecting plate 26 for transmitting shear stress between the beams and columns. This interconnection plate 26 has through holes 31
Has been formed.

The locking plates 4 and 20 can be further strengthened so that they do not bend themselves by additional stiffening members not shown. The stiffening member is centrally located to resist torque moments and converts some of it into bending moments that are transmitted to diagonal braces that intersect the joints.

In the case of columns that are severed as shown in FIGS. 1-4, the locking plates 4 and 20 are not welded together at the factory prior to frame assembly. However, it can be mounted in place by bolt connections. To this end, the locking plates 4 and 20 have two pairs of spacer members 19
Separated by. This member is constructed with a right angle or similar cross-sectional shape and is welded to plates 4 and 20 at one end. Further, a through hole 31 is formed. The attachment of these two spacer members 19 is done in-situ during frame assembly and allows transmission of bending pressure from the top to the bottom of the column. Furthermore, when this bolted joint is joined to the plate 3 associated with joint B, it also enables the transfer of shear stress from the beam 4 to the column 15.

With reference to a joint adapted for use with an integral post passing through the joint, the upper plate 20 is advantageously smaller than the lower plate 4. This is because the upper plate has a smaller radial spread than the lower plate to allow positioning of the beam relative to the column from above. Member A may include upper and lower connecting fins 65 and may also include peripheral through holes 27 for hinged connection of the vertical brace to the joint. These additional hinge connection means can be welded to the joint or supplied as separate parts and subsequently welded. In this case, those parts can be adjusted appropriately.

Member B is generally formed of a plurality of stress transmitting plates, preferably four plates. These plates are adapted to be attached to the ends of each beam 1 by welding or similar means. The first pair of these plates are substantially parallel and vertically spaced plates 2 and 28 which are attached to the upper and lower wings of the mating beam and which have through holes 21 'and 29' respectively. I have it.
The plates 2 and 28 have a large resistance force in comparison with the wing of the beam connected so as to resist a large moment in the fixed connection position, and have an appropriate length capable of welding the beam 1 to the part of the member B. 2 having bolts and bolted together
It has a width that allows for the positioning of 1'and 29 'and is dimensioned to account for the resistance of the braces that are joined to the joint. To simplify the assembly process, a small number of large diameter bolts should be used for the bolt connection to avoid weakening of the beam. Relatively large diameter through holes cannot be formed during beam assembly due to lack of space in the joint. Therefore, it is obvious that it is advantageous to be formed in the factory before the assembly takes place.

The side plate 2 is made shorter than the upper plate 28 to allow positioning of the beam from above. This is because the expansion of the locking plate 20 of the member A in the radial direction is different. The member B has a plate 3 according to FIG. 3, which is provided with a through hole 31 adapted to transfer the shear stress from the beam 1 to the part of the member A. This plate 3 is welded to the web of beams along the axis of the bolt connection of plates 2 and 28. It may also include optional through holes 32 for passing building equipment. Four
The second plate 30 is connected to the plates 2 and 28 and is adapted to transfer the torque induced by the beam 1 to the member A.

 The above-described structure of the joint provides the following effects.

Even in very small factories, prefabricated joints can be used to build unique structures, leading to the use of windproof brace reinforced frames. Steel construction is most suitable. Because all that has to be done is to loosen the bolts, prepare the elements of the part and weld them in the factory.
The member A is welded to one or a plurality of columns, and the member B is welded to one end of the beam. The only work required on the braces is to cut them to the required dimensions. In this way all structural defects are avoided, which starts with theoretical measures and makes it possible to obtain the regular-shaped structure initially required for seismic structures.

Another advantage is that any structure can be designed, operated and constructed in a very short engine. It is also possible to create a computer program.

This construction method using the joint of the present invention can be considered separately from the rotation tolerance because suitable adapters and spacers can be used in the connecting portion. The desired accuracy of the assembly can be ensured by prefabricated bolt connections made by professional personnel, as well as joint alignment.

If one considers the braces of the lattice framework, they do not have to be maximised and other shapes can be used for easy attachment to the joint. If the parts of the member A are to be connected to a few braces, the unnecessary parts of the joint can easily be cut off.

The dimensions of the joints can be varied so that lower floors have a higher resistance shape and higher floors have a less rigid shape, which allows good material distribution by theoretical calculations. The use of these joints can make the all-metal structure more competitive with respect to composite structures in reinforced concrete, and unlike reinforced concrete, diagonal tension bars are relatively inexpensive. It is possible to form a reinforcing brace having In general, the use of these joints reduces the overall weight of the structure and also ensures beam height uniformity at a cheaper investment. Local windproof braces are no longer required. Therefore, the stress concentration is reduced and the cost for the basic structure is reduced.

This proposed structure of the joint is made up of members A and B
Seismic energy can be lost by the inelastic deformation at the bolt connection portion caused by the through hole having an elliptical shape and the plastic deformation caused by the connection with the member B.

In fact, it is known that the behavior of bolted joints depends on the sliding movement with the connecting parts. It is known that this effect is not completely irregular, and is known to exert a positive effect on seismic resistance. Furthermore,
The suppleness, or flexibility, of structures incorporating bolted joints is at least equal to fully welded structures.

Finally, the use of relatively large diameter bolts resulted in an overall increase in mechanical resistance without compromising this flexibility or flexibility. Also, the dissipation of energy in the hysteresis cycle was significantly increased.

Finally, the proposed joint forms a plastic hinge, in particular at the passage point between the beam-shaped section and the section where the connection takes place. In fact, where the beam must be dimensioned to withstand moments approximately equal to the centerline moment but less than the maximum moment, the fixed joint is given the same dimensions as the beam with the flanged joint, Also, the cross section is sharply reduced.

The proposed joint is seen to allow the post to be assembled from the top. The pillars are lowered by a crane and guided to the site and automatically positioned to prevent them from falling. This is because the pillar leans against the joint and the member B of the joint cannot move in the horizontal direction.

In an exemplary joint construction, there are vertically extending columns, four beams orthogonal to one another, four or eight horizontal braces, and eight vertical windproof braces. . However, with some types of assembly, it is possible to achieve a different number of beams and braces by orienting at different angles and similarly varying the height of the beams. Other different angles in the combined sleeper can be obtained by orienting them to substantially align with plates 2 and 28 of member B and bending those plates in response to plate 30.

Claims (7)

[Claims] 1. A joint for a building frame that connects a beam to a column, which is connectable to the column and to the horizontal and vertical bracing members finally provided to the frame by a hinged connection. A first member (A) and at least one second member (B) connectable to the respective beams, wherein the first member (A) and at least one
The two second members (B) are provided with holes and corresponding bolts to connect them to each other by a sufficient resistance welded connection during final assembly of the building frame; In the joint, the first member (A) and the at least one second member (B) can be connected to the pillar and the beam, respectively, at mutually variable inclination angles that are variable, 2 members (B) are 4 plates (2,3,28,30),
That is, two substantially parallel and vertically-spaced plates (2,28), substantially parallel and vertically spaced, for transmitting a bending moment from the beam to the first member (A). ), A vertically extending plate (3) connected to the beam for transmitting shear stress from the beam to the first member (A), and the two substantially horizontally extending plates. A plate (30) extending between the (2, 28) and extending in the vertical direction and connecting these plates (2, 28) for transmitting the torque induced by the beam to the first member (A). And these four plates are connectable to the first member (A) by connection through bolts,
The joint characterized in that the member (B) has a structural strength higher than that of the beam connected thereto. 2. Joint according to claim 1, characterized in that the connections (21, 29, 31) through the bolts are independent of one another. 3. The joint according to claim 1 or 2, wherein the second member (B) has a varying portion at the point of connection with the beam, the variation being such that a plastic hinge is realized at this point. A joint that is characterized by being performed intermittently. 4. The joint according to claim 1, wherein the first member (A) receives one or more of the second members (B) and which extends through upper and lower bolts. The connection (21,29,31) is provided, and the first
The joint characterized in that the member (A) has higher structural strength than the second member (B). 5. The joint according to claim 4, wherein the first member (A) is provided with a central hole (23) for passing the pillar, and the first member (A) has a unitary structure. One of the further plates including a plate (5,26) for shear stress transmission connected to the further plate (4,20) to achieve
A joint characterized in that one (20) is smaller than the other further plate (4). 6. The joint according to claim 5, wherein the first member (A) is a bolt.
A plate (25) with holes (12) placed on said further plate (4,20) for connecting the two, said plate (25) supporting a support mold (8) A joint that is characterized. 7. The joint according to claim 4, wherein the first member (A) is connected to each other by a bolt connection (31, 21, 29) and at least one second member (B). Made of separate parts, said further plate (4,20) and said horizontally long plate (2,28)
Is provided with a spacer member (19) having a hole corresponding to the bolt connection (31) so as to obtain a clearance.