CN113447427B - An anti-progressive collapse test device of a curved beam-column structure - Google Patents

Abstract

The invention discloses an anti-continuous collapse test device of an arc-shaped beam-column structure, which comprises an arc-shaped beam-column structure test piece, and is characterized in that it also includes a column head restraint device; the arc-shaped beam-column structure test piece includes an arc-shaped beam-column structure test piece The beam and the supporting columns located at both ends of the arc-shaped beam, and the column head with no support at the lower end in the middle of the arc-shaped beam; the column head restraint device includes a bottom plate and a limiting column arranged on the bottom plate, and the limiting column is provided with A limiting slot along the height direction of the limiting column; the column head of the curved beam-column structure test piece is located in the limiting slot and can slide up and down along the limiting slot. The invention has the advantages that: the rotation and horizontal deformation of the column head in the test piece are constrained, only the vertical degree of freedom is available, and the collapse process of the curved beam structure can be truly simulated; the restraint device and the column head are in contact with each other through a polytetrafluoroethylene plate , the friction force is small, which reduces the vertical resistance provided by the device to the test piece and avoids interference with the test results.

Description

An anti-progressive collapse test device of a curved beam-column structure

technical field

The invention belongs to the field of disaster prevention and mitigation of building structures, and relates to an anti-continuous collapse test device of an arc-shaped beam-column structure.

Background technique

Structural progressive collapse events caused by natural disasters often cause huge casualties and property losses, so the design of structural progressive collapse resistance is very important. The structure has been reasonably designed to resist progressive collapse. When accidental loads cause local damage to the structure, the structure can redistribute the internal force through the backup load path to prevent further expansion of the damage, thereby reducing casualties and reducing the degree of structural damage as much as possible. However, the ability to resist the continuous collapse of the structure often needs to be clarified through experiments.

In the prior art, some researchers have proposed various progressive collapse resistance test methods, such as a concrete slab-column structure progressive collapse performance test device and test method. The purpose of the invention is to realize the progressive collapse test of the slab-column structure. The internal force redistribution of the column structure when the structure is partially damaged and failed due to accidental load; a steel frame continuous collapse dynamic test device, the purpose of which is to realize the steel frame continuous collapse dynamic test, through which the test can be carried out outdoors, And achieve instant loading.

Nowadays, various architectural forms emerge in endlessly, and novel and unique architectural shapes are also of different styles. The shapes of curved windows, curved balconies, and curved corners determine the appearance of curved beam components in the structure. However, there is no progressive collapse test device for curved beam-column structures at present. The collapse mechanism of curved beams is different from that of straight beams. Under non-eccentric vertical loads, the deformation and internal force outside the plane of a straight beam are both zero; under the action of torque, the deformation and internal force in the bending direction are also zero, that is, the straight line The bending internal force and torque of the beam are independent of each other and do not affect each other. But the curved beam is different, there is a bending-shear-torsional coupling phenomenon under the action of vertical load. Therefore, in the unconstrained condition, during the collapse of the arc-shaped beam-column structure, the arc-shaped beam will have out-of-plane displacement and rotation, causing the head of the failed column to overturn and cannot move vertically downward. In actual engineering, considering that the failure of a general frame structure column may be located on different floors and plane positions, the upper floor and surrounding structures will have a restraint effect on the column head of the failed column, so that it can only move vertically downward.

To sum up, the problem existing in the prior art is that the column head must be constrained to limit the out-of-plane displacement and rotation, so as to conform to the real collapse state of the arc-shaped frame structure. At the same time, the vertical resistance provided by the friction between the test piece and the restraint device must be eliminated, otherwise accurate test results cannot be obtained. Furthermore, for arc-shaped beams with different arc angles, the relative positions of column heads are different, and the restraint device must have strong applicability. Finally, there may still be errors in the fabrication of test pieces and devices, which will have a certain impact on the installation of various parts in the test system.

Contents of the invention

In view of the above-mentioned existing technical problems, the present invention proposes a progressive collapse test device for curved beam-column structures, so as to realize the real collapse state of curved frame structures and obtain accurate test results.

The technical scheme that the present invention solves the problems of the technologies described above is as follows:

An anti-continuous collapse test device of an arc-shaped beam-column structure, comprising an arc-shaped beam-column structure test piece, characterized in that it also includes a column head restraint device; the arc-shaped beam-column structure test piece includes an arc-shaped beam and a The supporting columns at the two ends of the arc-shaped beam are unsupported column heads at the lower end in the middle of the arc-shaped beam; the column head restraint device includes a base plate and a limit column arranged on the base plate, and a limit column along the limit column is arranged on the limit column. A limit slot in the height direction; the column head of the curved beam-column structure test piece is located in the limit slot and can slide up and down along the limit slot.

A rectangular PTFE slide-type rubber pad for reducing frictional resistance is arranged on the surface of the column head in contact with the limiting groove.

A polytetrafluoroethylene plate for reducing frictional resistance is also provided on the surface of the limiting groove in contact with the column head.

The limit column includes a fixed steel column and an adjustable steel column oppositely arranged, and half-open grooves are respectively arranged on the opposite sides of the fixed steel column and the adjustable steel column, and the two half-open grooves constitute the limit slot.

The fixed steel column includes a main body and a stiffening rib; the main body is welded by two I-beams, and the stiffening rib is provided along the height direction of the main body; , the width of the constraint plate shall not exceed the distance between the end side of the curved beam and the side of the column head.

The adjustable steel column includes a main body, a stiffener and a perforated bottom plate; the main body is welded by two I-beams, and the stiffener is arranged along the height direction of the main body; the bottom of the main body is welded with a perforated bottom plate; the The side of the flange on one side of the main body of the adjustable steel column is welded with a restraint plate, and the width of the restraint plate does not exceed the distance between the side of the arc beam end and the side of the column head.

The bottom plate of the column head constraint device is a steel plate; grooves are opened near the edge of the bottom plate, and bolt track holes are pre-opened at corresponding positions in the middle of the bottom plate. The bolt track holes correspond to the holes of the adjustable steel column perforated bottom plate one by one.

The column head restraint device also includes pressure beams; the pressure beams are placed on both sides of the bottom plate, the grooves reserved for the pressure beams correspond to the bottom plate grooves, and the bottom plate is anchored to the ground beams of the laboratory by anchor bolts.

The pressure beam is formed by welding two channel steels with reserved channels, and the width of the reserved channels of the two channel steels is consistent with the width of the bottom plate channel.

The fixed steel column is welded on the bottom plate; the adjustable steel column is detachably connected to the bottom plate through high-strength bolts.

Bolt holes are opened at the flanges of the fixed steel column and the lower end of the adjustable steel column. After the adjustment of the adjustable steel column is completed, the adjustable steel column is connected with the fixed steel column through a pull screw to limit the adjustable Slip of the steel column along the direction of the track hole.

The anti-sequential collapse test device of the curved beam-column structure also includes an actuator and a column head converter, and the column head converter is connected to the actuator.

Compared with the prior art, the present invention has the following beneficial effects:

1) When the actuator exerts pressure, the restraint device constrains the out-of-plane displacement and rotation of the column head so that it can only move vertically downward, realizing the real collapsed state of the arc-shaped frame structure. It is applicable to both static collapse test and dynamic collapse test.

2) The arrangement of the tetrafluoroethylene plate and the rectangular tetrafluoro sliding plate rubber pad, together with lubricating oil, greatly reduces the friction between the column head and the device, reducing the impact on the test results. In addition, the setting of the rectangular PTFE sliding plate rubber pad avoids the damage of the column head and the restraint device during the test.

3) The cooperation between the bolt track hole and the pull screw can not only adjust the error caused by the device in the production process, but also limit the sliding of the adjustable steel column along the track hole direction.

4) The design of the channel makes the column head restraint device suitable for the collapse test of curved beams under different curvatures. At the same time, it is also suitable for channel-type or hollow-type laboratory floors, saving resources more.

5) The column head converter can realize the size coordination between the pressure head of the actuator and the column head, and at the same time, it does not affect the use of the column head restraint device.

Description of drawings

Fig. 1 is the general schematic diagram of the anti-progressive collapse test of the curved beam-column structure;

Fig. 2 is a schematic diagram of the curved beam-column structure for the anti-progressive collapse test of the curved beam-column structure;

Fig. 3 is a schematic diagram of the column head restraint device for the anti-progressive collapse test of the curved beam-column structure;

Figure 4 is a structural schematic diagram of a fixed steel column;

Fig. 5 is a structural schematic diagram of an adjustable steel column;

Fig. 6 is the structural representation of pressure beam;

Fig. 7 is the structural representation of base plate;

Fig. 8 is a structural schematic diagram of a column head converter;

In the figure: 1. Laboratory floor; 2. Actuator; 3. Curved beam and column structure; 4. Cap restraint device; 31. Curved beam; 311. Cap; 32. Anchor bolt; 33. First polymer PTFE plate; 34. Rectangular PTFE slide rubber pad; 41. Bottom plate; 411. Anchor bolt; 412. Bolt track hole; 42. Pressure beam; 421. Connecting plate; 422. Channel steel; 43. Adjustable Steel column; 431, hole bottom plate; 432, positioning bolt; 433, adjustable steel column I-beam splicing column; 434, adjustable steel column side stiffener; 435, adjustable steel column top surface stiffener; 436, adjustable Adjusting steel column restraint plate; 44, fixed steel column; 441, fixed steel column restraint plate; 442, fixed steel column I-beam splicing column; 443, fixed steel column side stiffener; 444, fixed steel column Top stiffener; 45, second polytetrafluoroethylene plate; 46, pull screw; 461, bolt hole; 5, column head converter.

Detailed ways

The principles and features of the present invention are described below in conjunction with the accompanying drawings, and the examples given are only used to explain the present invention, and are not intended to limit the scope of the present invention.

Embodiment is basically shown in accompanying drawing 1-8.

Accompanying drawing 1 is the concrete embodiment of anti-progressive collapse test of curved beam-column structure, and present embodiment comprises laboratory floor 1, actuator 2, test specimen curved beam-column structure 3, column head constraint device 4 and column head converter 5.

As shown in FIG. 2 , the arc-shaped beam-column structure 3 includes an arc-shaped beam 31 , anchor bolts 32 , a first polytetrafluoroethylene plate 33 , and a rectangular tetrafluoro-slide rubber pad 34 . In the middle of the arc beam 31 is a column head 311 .

As shown in FIG. 3 , the column head constraint device 4 includes a bottom plate 41 , a pressure beam 42 , an adjustable steel column 43 , a fixed steel column 44 , a polytetrafluoroethylene plate 45 , and a tension screw 46 .

As shown in accompanying drawing 6 and accompanying drawing 7, two channel steels 422 are connected into a pressure beam 42 with a channel under the welding of the connecting plate 421; Bolt track holes 412 are pre-opened; anchor bolts 411 connect the pressure beam 42 and the bottom plate 41 to the laboratory floor 1 .

The design of the channel makes the column head restraint device suitable for the collapse test of curved beams under different curvatures. At the same time, it is also suitable for channel-type or hollow-type laboratory floors, saving resources more. Assume that the span (chord length) of the curved beam is L, the central angle is θ, the length of the bottom plate of the restraint device is H, the distance between the anchor point of the anchor bolt and the outer edge of the long side of the bottom plate of the restraint device is S, and the distance between the channels of the test chamber is l. According to the relative relationship, we can know that:

S＝L/(2sin(θ/2))-(Lcot(θ/2))/2+H/2-l/2

For any central angle, the position of the corresponding anchor point can be determined, and the length of the bottom plate and channel of the restraint device can be designed accordingly to meet the needs of collapse tests of arc beams with different curvatures and enhance the applicability.

As shown in accompanying drawing 1 and accompanying drawing 3, fixed steel column 44 is directly welded on the bottom plate 41; 505mm, 905mm, and 1205mm are respectively welded with fixed steel column side stiffeners 443 at the bayonet joints of the outer flanges on both sides of the fixed steel column, and welded with solid joints at the top inner flange bayonet of the fixed steel column I-beam splicing column 442. Stiffeners 444 on the top surface of the steel column, and bolt holes 461 are opened at the flanges on both sides of the steel column I-steel splicing column 442 at the lower vertical position; the steel column restraint plate 441 is welded and fixed on the On the post 442 of the steel splicing column. A second polytetrafluoroethylene plate 45 is pasted inside the semi-open groove formed by the flange of the I-beam splicing column 422 of the fixed steel column and the two restraining plates 441 of the fixed steel column.

As shown in accompanying drawings 1 and 4, the adjustable steel column 43 and the fixed steel column 44 are composed in the same way, and the two pieces of I-shaped steel are welded and spliced into an adjustable steel column I-shaped steel spliced column 433. Adjustable steel column side stiffeners 434 are respectively welded to the outer flange bayonets on both sides of the top surface at 0mm, 505mm, 905mm, and 1205mm, and the inner flange bayonets on the top surface of the adjustable steel column I-beam splicing column 433 Adjustable steel column top surface stiffeners 435 are welded at the lower position, and bolt holes 461 are opened at the flanges on both sides of the adjustable steel column I-steel splicing column 433 at the vertical lower position; the adjustable steel column constraint plate 436 is welded and fixed on the adjustable steel column Adjust the steel column I-beam splicing column 433, and at the same time, the adjustable steel column 43 is welded with a perforated bottom plate 431 at the bottom of the column. The second polytetrafluoroethylene plate 45 is pasted on the inner side of the semi-open groove formed by the flange of the adjustable steel column I-beam splicing column 433 and two adjustable steel column restraint plates 436 .

As shown in Figure 1, after connecting the bottom plate 41 with the laboratory ground 1 through the pressure beam 42, since the fixed steel column 44 is welded to the bottom plate 41, the position of the fixed steel column 44 has also been determined, and the adjustable steel column 44 is adjusted. The column 43 makes the adjustable steel column restraining plate 436 and the fixed steel column 441 roughly wrap the column head. After the adjustable steel column 43 and the bottom plate 41 are fixed by the positioning bolt 432, the fixed steel column 44 and the adjustable steel column 44 are connected by the tension screw 46. The adjusting steel column 43 is connected as a whole, and now the column head constraint device 4 is installed.

As shown in accompanying drawings 1 and 7, the column head converter 5 is connected to the actuator 2 and placed on the test column head, and connected to the column head by high-strength bolts.

The possible displacement of the column head is constrained by two steel columns, the friction between the column head and the restraint device is reduced by the polytetrafluoroethylene plate, the error caused by the device in the production process can be adjusted by the bolt track hole, and the different curvatures are made by the channel. The curved beam test does not need to replace the device, and the pressure heads of different sizes can be applied smoothly through the column head converter, so that the progressive collapse test of the curved beam-column structure can be better completed.

Claims (7)

1. a kind of arc-shaped beam-column structure anti-progressive collapse test device, comprises arc-shaped beam-column structure test piece, is characterized in that: also comprises a cap restraining device; Described arc-shaped beam-column structure test piece comprises an arc-shaped beam and The support columns located at both ends of the arc-shaped beam are unsupported column heads in the middle of the arc-shaped beam; the column head restraint device includes a bottom plate and a limiting column arranged on the bottom plate, and an edge limiting column is arranged on the limiting column. The limit groove in the height direction of the position column; the column head of the curved beam-column structure test piece is located in the limit groove and can slide up and down along the limit groove; the surface in contact with the limit groove on the column head is provided with a useful A rectangular PTFE slide-type rubber pad for reducing frictional resistance; a polytetrafluoroethylene plate for reducing frictional resistance is also provided on the surface in contact with the column head on the limiting groove; the limiting column includes an opposite fixed connection For the steel column and the adjustable steel column, semi-open slots are respectively provided on opposite sides of the fixed steel column and the adjustable steel column, and the two semi-open slots constitute the limiting slot; The side of the flange on one side of the main body of the fixed steel column is welded with a restraint plate, and the width of the restraint plate does not exceed the distance between the side of the arc beam end and the side of the column head; The side of the flange on one side of the main body of the adjustable steel column is welded with a restraint plate, and the width of the restraint plate does not exceed the distance between the side of the arc-shaped beam end and the side of the column head; There is a channel near the edge of the bottom plate, and bolt track holes are pre-opened at the corresponding position in the middle of the bottom plate; bolt holes are opened at the flanges of the fixed steel column and the lower end of the adjustable steel column, and the adjustable The steel column is connected with the fixed steel column. 2. The anti-progressive collapse test device for curved beam-column structures according to claim 1, characterized in that: the fixed steel column comprises a fixed steel column main body and stiffeners; the fixed steel column main body consists of two The I-shaped steel is welded, and the stiffening rib is provided along the height direction of the main body of the fixed steel column. 3. The anti-progressive collapse test device of curved beam-column structure according to claim 2, characterized in that: the adjustable steel column comprises an adjustable steel column main body, stiffeners and a perforated bottom plate; the adjustable steel column main body consists of Two I-beams are welded, and the stiffening ribs are provided along the height direction of the main body; the bottom of the main body of the adjustable steel column is welded with the perforated bottom plate, and the holes of the perforated bottom plate are connected with the bolt track holes one by one correspond. 4. The progressive collapse test device for curved beam-column structures according to claim 1, characterized in that: the bottom plate is a steel plate. 5. The anti-progressive collapse test device for curved beam-column structures according to claim 1, characterized in that: the column head restraint device also includes pressure beams; The channel of the bottom plate is corresponding, and the bottom plate is anchored to the ground beam of the laboratory through anchor bolts. 6. The anti-continuous collapse test device for curved beam-column structures according to claim 5, characterized in that: the pressure beam is welded by connecting plates after two channels are reserved for channels, and the two channels The width of the steel reserved channel is consistent with the width of the bottom plate channel. 7. The anti-progressive collapse test device for curved beam-column structures according to claim 1, characterized in that: the anti-progressive collapse test device for curved beam-column structures also includes an actuator and a column head converter, and the column head A converter is connected to the actuator.

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