Concrete-filled steel tubular column anti-blast test device and test method

Abstract

The present application belongs to the technical field of concrete structure anti-blast, and particularly relates to a kind of steel pipe concrete column anti-blast test device and testing method, comprising: frame support system, secondary fire simulation mechanism and explosion simulation mechanism, the frame support system is used to fixedly install steel pipe concrete column, the secondary fire simulation mechanism is used to construct fire environment outside steel pipe concrete, the explosion simulation mechanism is used to implement explosion operation to steel pipe concrete column, the present application simulates explosion and secondary fire phenomenon caused by explosion in steel pipe concrete column outside in turn, through real environment simulation, the damage law of experimental steel pipe concrete column under explosion, secondary fire phenomenon, and according to the experimental results, reversely adjust the proportioning, shape and other parameters of steel pipe concrete column, and provide great convenience for the optimization of steel pipe concrete structure through reliable data support.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of concrete structure blast resistance, and in particular relates to a steel pipe concrete column blast resistance test device and a testing method. BACKGROUND

[0002] Steel pipe concrete structure is one of the structural forms widely used in modern buildings. It realizes the synergistic optimization of material performance by means of the combined effect of steel and concrete, and exhibits multiple advantages such as excellent bearing capacity, excellent seismic performance and convenient construction.

[0003] In the research and improvement process of steel pipe concrete structure, the optimization of fire resistance is not only a key link to improve the overall performance, but also a focus of attention in the current research field. The fire resistance of steel pipe concrete structure mainly involves the fire resistance of the material itself and the heat insulation and fire retardation efficiency of the external fire protection layer. When the steel pipe concrete structure is affected by explosion at the same time of fire, the steel pipe concrete structure may only be slightly or moderately damaged under the action of explosion, but under the action of secondary fire caused by explosion, the mechanical properties of the structure will be further degraded, and local damage or even overall collapse will occur. In this process, the explosion may cause the fragmentation and peeling of the fire protection layer of the component, as well as the overall bending of the component, the cracking of the concrete and other damages, thereby reducing the bearing capacity, stiffness and fire resistance limit of the component, so that the fire resistance limit of the structure is lower than that under the action of single fire.

[0004] In related research, such as the steel pipe concrete column blast resistance test device and testing method disclosed in the scheme with the application number CN2023110494007 in the related technology, and the test device for testing the blast resistance of concrete column under axial compression state disclosed in the scheme with the application number CN2025102040459, the blast resistance research of such steel pipe concrete column is mainly aimed at the blast resistance research of the component itself, and there is no related research on the damage of the fire protection layer, and there is no related research under the combined action of explosion and secondary fire.

[0005] In view of this, the present application provides a steel pipe concrete column blast resistance test device and a testing method to solve the above technical problems. SUMMARY

[0006] In order to make up for the shortcomings of the prior art and solve the above technical problems, the present application provides a steel pipe concrete column blast resistance test device and a testing method.

[0007] The technical solution adopted by the present application to solve the technical problems is: a steel pipe concrete column blast resistance test device according to the present application, comprising:

[0008] a frame support system for fixedly installing a steel pipe concrete column;

[0009] a secondary fire simulation mechanism for simulating a fire environment outside the steel pipe concrete, the secondary fire simulation mechanism comprising a firing gun and a combustible gas injection pipe;

[0010] and an explosion simulation mechanism for performing an explosion operation on the steel pipe concrete column, the explosion simulation mechanism comprising:

[0011] an explosion chamber installed on the frame support system, the explosion chamber covering the outside of the steel pipe concrete column;

[0012] a cartridge installed in the explosion chamber, the cartridge containing an electronic detonator.

[0013] Preferably, the explosion chamber comprises an explosion-proof chamber body, an explosion cavity, and a drainage steel plate.

[0014] The explosion-proof chamber body is a cylindrical cavity structure, and a mounting slot is formed at the top end of the explosion-proof chamber body, the steel pipe concrete column is installed in the explosion-proof chamber body through the mounting slot, and the steel pipe concrete column is coaxially arranged with the explosion-proof chamber body.

[0015] An explosion cavity is formed on the explosion-proof chamber body, a loading hole is formed on the explosion-proof chamber body, the loading hole is in communication with the explosion cavity, the cartridge is installed in the explosion cavity through the loading hole, and a hatch is hingedly installed on the explosion-proof chamber body, and the hatch is used to close the loading hole.

[0016] A vertically arranged drainage steel plate is installed in the explosion-proof chamber body, and the drainage steel plate is used to guide the airflow generated by the explosion towards the steel pipe concrete column.

[0017] Preferably, the explosion cavity is designed in a ring shape, the drainage steel plate extends into the explosion cavity, a control slot is formed on the side of the explosion-proof chamber body away from the loading hole, an arc-shaped extension rod is installed in the control slot, the arc-shaped extension rod is an electric telescopic rod, the arc-shaped extension rod extends into the explosion cavity, the arc-shaped extension rod is connected with the drainage steel plate, and the arc-shaped extension rod is used to adjust the interval distance between the two drainage steel plates.

[0018] Preferably, a spring plate is fixedly installed at the end of the arc-shaped extension rod, and the arc-shaped extension rod is elastically connected with the drainage steel plate through the spring plate.

[0019] Preferably, the explosion cavity is designed in a plurality of numbers, and the explosion cavities are uniformly arranged along the height direction of the explosion-proof chamber body, and the cross-sectional diameter of the explosion cavity increases as the distance from the steel pipe concrete column shortens.

[0020] Preferably, the explosion-proof chamber is provided with a heat insulation chamber, the heat insulation chamber is located between the explosion-proof chamber and the steel pipe concrete column, the heat insulation chamber is made of heat insulation material, and the secondary fire simulation mechanism is installed on the inner side of the heat insulation chamber.

[0021] Preferably, the frame support system is composed of a support table and a lifting frame, the lifting frame is a frame structure with an open top end, the support table is fixedly installed in the middle of the lifting frame, the explosion-proof chamber is lifted in the lifting frame by a steel cable, the explosion-proof chamber is located directly above the support table, the explosion-proof chamber is provided with an assembly groove at the bottom end, the heat insulation chamber is slidably sleeved on the support table and the steel pipe concrete column, and the heat insulation chamber is provided with a hydraulic lifting cylinder at the bottom.

[0022] Preferably, the explosion-proof chamber is provided with a lifting plate, the outer diameter of the lifting plate is greater than the diameter of the assembly groove, and the inner diameter of the lifting plate matches the outer diameter of the steel pipe concrete column.

[0023] Preferably, the heat insulation chamber has a diameter smaller than that of the assembly groove, and the heat insulation chamber is provided with a separation column at the top end.

[0024] A steel pipe concrete column explosion resistance test method, the method comprises the following steps:

[0025] S1: the steel pipe concrete column sample is coaxially lifted and installed on the support table, the hatch is opened synchronously, and the cartridge is placed in the explosion chamber through the filling hole;

[0026] S2: continuously tighten the steel cable, lift the explosion-proof chamber until the bottom end of the explosion-proof chamber is higher than the top end of the support table, and the lifting plate automatically descends to block the assembly groove;

[0027] S3: adjust the length of the arc-shaped extension rod, push the position of the drainage steel plate, adjust the area of the explosion acting on the steel pipe concrete column, and then detonate the electronic detonator in the cartridge;

[0028] S4: after the explosion, the hydraulic lifting cylinder is started, the heat insulation chamber is pushed up until the bottom end of the heat insulation chamber is separated from the support table, the secondary fire simulation mechanism is started, and a fire environment is created outside the steel pipe concrete column;

[0029] S5: after the secondary fire simulation is completed, the heat insulation chamber and the explosion-proof chamber are lowered in sequence, and the steel pipe concrete parameters are observed and recorded.

[0030] The beneficial effects of the present application are as follows:

[0031] 1. The steel pipe concrete column blast resistance test device and test method, which simulates explosion and secondary fire phenomenon caused by explosion on the outside of the steel pipe concrete column in sequence, simulates the real environment, experiments the damage law of the steel pipe concrete column under explosion and secondary fire phenomenon, and reversely adjusts the proportioning, shape and other parameters of the steel pipe concrete column according to the experimental results, so as to provide great convenience for the optimization of the steel pipe concrete structure with reliable data support.

[0032] 2. The steel pipe concrete column blast resistance test device and test method, which connects the explosion-proof bin body and the heat insulation bin in a mutual sleeving mode, and lowers the explosion impact on the heat insulation bin in the explosion simulation process, so as to reduce the damage probability of the heat insulation bin made of heat insulation material, limits the flame range by the heat insulation bin in the secondary fire simulation process, and effectively reduces the damage probability of the explosion simulation mechanism caused by high temperature by means of the heat insulation bin, the hindering of heat and the non-direct contact between the heat insulation bin and the explosion simulation mechanism. BRIEF DESCRIPTION OF DRAWINGS

[0033] The application will be further described below with reference to the drawings.

[0034] Figure 1 is a perspective view of the application;

[0035] Figure 2 is another perspective view of the application from another angle;

[0036] Figure 3 is a perspective view of the application in an explosion simulation state;

[0037] Figure 4 is a partial sectional view of the explosion bin in the application;

[0038] Figure 5 is an internal structure diagram of the explosion-proof bin body in the application;

[0039] Figure 6 is an assembly perspective view of the drainage steel plate and the arc-shaped extension rod in the application;

[0040] Figure 7 is a perspective view of the heat insulation bin in the application;

[0041] Figure 8 is a sectional view of the application in a secondary fire simulation state;

[0042] Figure 9 is a method flow chart of the application;

[0043] In the figure: 1, support platform; 11, hoisting frame; 12, hydraulic lifting cylinder; 13, steel cable; 2, explosion-proof bin body; 21, mounting groove; 22, explosion chamber; 23, filling hole; 24, hatch; 25, drainage steel plate; 26, control groove; 27, arc-shaped extension rod; 28, spring plate; 3, heat insulation bin; 31, separation column; 4, assembly groove; 41, lifting plate; 5, steel pipe concrete column; 6, combustible gas injection pipe; 61, ignition gun. DETAILED DESCRIPTION

[0044] In order to make the technical means, creative features, purposes and effects of the present application easy to understand, the present application is further described below in combination with specific embodiments.

[0045] As shown in Figures 1 to 9 , the steel pipe concrete column explosion test device comprises:

[0046] A frame support system is used to fix and install the steel pipe concrete column 5.

[0047] A secondary fire simulation mechanism is used to simulate a fire environment outside the steel pipe concrete column, and the secondary fire simulation mechanism is composed of an ignition gun 61 and a combustible gas injection pipe 6.

[0048] An explosion simulation mechanism is used to perform an explosion operation on the steel pipe concrete column 5, and the explosion simulation mechanism comprises:

[0049] An explosion bin is installed on the frame support system, and the explosion bin is arranged outside the steel pipe concrete column 5.

[0050] A cartridge is installed in the explosion bin, and the cartridge is provided with an electronic detonator.

[0051] The explosion bin comprises an explosion-proof bin body 2, an explosion chamber 22 and a drainage steel plate 25.

[0052] The explosion-proof bin body 2 is a cylindrical cavity structure, and a mounting groove 21 is formed at the top end of the explosion-proof bin body 2.

[0053] The explosion-proof bin body 2 is provided with an explosion chamber 22, and the explosion-proof bin body 2 is provided with a filling hole 23.

[0054] The explosion-proof chamber body 2 is internally provided with vertically arranged drainage steel plates 25, which are used to guide the airflow generated by the explosion towards the steel pipe concrete column 5.

[0055] In the research of the effect of explosion and secondary fire caused by explosion on the steel pipe concrete column 5, in order to simulate the actual situation as much as possible, explosion simulation mechanism and secondary fire simulation mechanism are provided in the application, by creating explosion atmosphere and secondary fire atmosphere on the outside of the steel pipe concrete column 5 in turn, the steel pipe concrete column 5 is subjected to explosion impact and fire roasting in turn, finally according to the parameter change of the steel pipe concrete column 5 before and after the experiment, the damage of explosion and secondary fire to the steel pipe concrete column 5 is judged, and the experimental results are reversely deduced, which has certain reference effect on optimizing and adjusting the performance of the steel pipe concrete column 5.

[0056] Specifically, in the application, in order to simulate the influence of explosion and secondary fire caused by explosion on the steel pipe concrete column 5 as much as possible, during the experiment, the steel pipe concrete column 5 is first fixed by using a frame support system, and in order to enhance the effect of simulating reality, an axial compression mechanism is also installed on the frame support system during specific implementation, by applying pressure to the top end of the steel pipe concrete column 5, the load-bearing state of the steel pipe concrete column 5 arranged in the building is simulated, then the hatch 24 is opened, the cartridge is installed in the explosion chamber 22, and the electronic detonator is started by remote control away from the experimental device, so that explosion occurs in the explosion chamber 22, the impact generated by the explosion is guided by the drainage steel plates 25 and impacts on the steel pipe concrete column 5, under the action of the impact force, the fireproof layer and the concrete layer of the steel pipe concrete column 5 are damaged, then through the secondary fire simulation mechanism, combustible gas is pumped into the explosion-proof chamber body 2, and the combustible gas is ignited under the cooperation of the ignition gun 61, according to the pre-set secondary fire simulation plan, the temperature, combustion time and other parameters in the explosion-proof chamber body 2 are actively adjusted, so that the steel pipe concrete column 5 is subjected to fire roasting, after the fire ends, the damage and deformation of the surface fireproof layer, internal concrete layer and steel pipe layer of the steel pipe concrete column 5 are measured, observed and recorded, then the steel pipe concrete column 5 is replaced, different cartridge quantities, fire temperatures and other parameters are replaced according to the experimental process to perform multiple experiments, and finally the influence result of explosion and secondary fire caused by explosion acting on the steel pipe concrete column 5 is output.

[0057] The application simulates explosion and secondary fire caused by explosion on the outside of the steel pipe concrete column 5 in turn, simulates the real environment, experiments the damage law of the steel pipe concrete column 5 under the explosion and secondary fire phenomenon, and reversely adjusts the ratio, shape and other parameters of the steel pipe concrete column 5 according to the experimental results, which provides great convenience for the optimization of the steel pipe concrete structure by reliable data support.

[0058] Meanwhile, in the application, the setting of the explosion-proof chamber body 2 and the explosion cavity 22 not only makes the filling of the cartridge more convenient, but also matches the drainage steel plate 25 to guide the impact generated by the explosion, control the area and position of the explosion impact on the steel pipe concrete column 5, and enhance the controllability of the damage caused by the explosion to the steel pipe concrete column 5, thereby providing convenience for the design of different parameter experimental groups.

[0059] As a preferred embodiment of the application, the explosion cavity 22 is annularly designed, the drainage steel plate 25 extends into the explosion cavity 22, the control groove 26 is formed on the side of the explosion-proof chamber body 2 away from the filling hole 23, the arc-shaped extension rod 27 is installed in the control groove 26, the arc-shaped extension rod 27 is an electric telescopic rod, the arc-shaped extension rod 27 extends into the explosion cavity 22, the arc-shaped extension rod 27 is connected with the drainage steel plate 25, and the arc-shaped extension rod 27 is used to adjust the interval distance between the two drainage steel plates 25.

[0060] It should be noted that, in the application, the arc-shaped extension rod 27 is an electric telescopic rod, specifically, the arc-shaped extension rod 27 is composed of a rod body and an electric control system, the length of the arc-shaped extension rod 27 is adjusted by the electric control system, and after adjustment, the arc-shaped extension rod 27 is in a self-locking state, that is, the length of the arc-shaped extension rod 27 is in a fixed state, so that when the explosion impact acts on the drainage steel plate 25, the arc-shaped extension rod 27 supports the drainage steel plate 25. In other embodiments of the application, the arc-shaped extension rod 27 can also be a hydraulic telescopic rod, the length of the arc-shaped extension rod 27 is adjusted by adjusting the hydraulic strength, and after adjustment, the length of the arc-shaped extension rod 27 is locked.

[0061] The end of the arc-shaped extension rod 27 is fixedly installed with a spring plate 28, the arc-shaped extension rod 27 is elastically connected with the drainage steel plate 25 through the spring plate 28, the impact force during the explosion acts on the drainage steel plate 25 and pushes the drainage steel plate 25 to move, at this time, the spring plate 28 between the arc-shaped extension rod 27 and the drainage steel plate 25 can buffer the explosion impact force by using the elastic force, thereby effectively reducing the probability of excessive damage of the drainage steel plate 25 and the arc-shaped extension rod 27 during the explosion process.

[0062] The explosion cavity 22 is designed in plurality, and the explosion cavities 22 are uniformly arranged along the height direction of the explosion-proof chamber body 2, and the cross-sectional diameter of the explosion cavity 22 increases with the shortening of the distance from the steel pipe concrete column 5.

[0063] To further enhance the ease of adjusting the position and area of ​​the steel-concrete composite column 5 under blast impact, this invention provides a plurality of blast chambers 22 within the explosion-proof chamber 2, arranged along the height of the chamber 2 in a ring shape. During actual adjustment, the positions of the two drainage steel plates 25 are adjusted by changing the lengths of the two arc-shaped extension rods 27, under the elastic connection of the spring plate 28. Since the two drainage steel plates 25 are located on both sides of the filling hole 23, and the drainage steel plates 25 are within the ring of the explosion-proof chamber 2... In the circumferential direction, the gap between the explosion chamber 22, the inner cavity of the explosion-proof chamber 2, and the steel-concrete composite column 5 is sealed, causing the explosion-proof chamber 2 to form two chambers. Therefore, the change in the position of the diversion steel plate 25 causes the impact area of ​​the explosive cartridge on the steel-concrete composite column 5 to change when it explodes. The setting of multiple explosion chambers 22 makes the installation position, number, and dispersion of the explosive cartridges highly adjustable, which provides convenience for various operations such as explosion position, explosion uniformity, and pinpoint explosion. In multiple tests, it also provides certain convenience for the richness of experimental data.

[0064] In a preferred embodiment of the present invention, an insulated chamber 3 is installed inside the explosion-proof chamber 2. The insulated chamber 3 is located between the explosion-proof chamber 2 and the steel-concrete composite column 5. The insulated chamber 3 is made of heat-insulating material, and the secondary fire simulation mechanism is installed inside the insulated chamber 3.

[0065] The frame support system consists of a support platform 1 and a hoisting frame 11. The hoisting frame 11 is a frame structure with an open top. The support platform 1 is fixedly installed in the middle of the hoisting frame 11. The explosion-proof chamber 2 is hoisted inside the hoisting frame 11 by steel cables 13. The explosion-proof chamber 2 is located directly above the support platform 1. An assembly groove 4 is provided at the bottom of the explosion-proof chamber 2. The heat insulation chamber 3 is slidably fitted on the support platform 1 and the steel pipe concrete column 5. A hydraulic lifting cylinder 12 is installed at the bottom of the heat insulation chamber 3. The heat insulation chamber 3 enters and exits the explosion-proof chamber through the assembly groove 4.

[0066] A lifting plate 41 is slidably installed inside the explosion-proof chamber 2. The outer diameter of the lifting plate 41 is larger than the diameter of the assembly groove 4. The inner diameter of the lifting plate 41 matches the outer diameter of the steel pipe concrete column 5. The heat insulation chamber 3 is an incomplete cylindrical structure, and the lifting plate 41 is an incomplete annular structure with notches in both directions. After the diversion steel plate 25 approaches the assembly groove 4, the total width of the diversion steel plate 25 and the assembly groove 4 is less than the width of the notch.

[0067] The diameter of the heat insulation chamber 3 is smaller than the diameter of the assembly groove 4. A separation column 31 is installed at the top of the heat insulation chamber 3, which separates the lifting plate 41 from the heat insulation chamber 3.

[0068] It should be noted that before the heat insulation chamber 3 rises and after the explosion simulation ends, the flow diversion steel plate 25 is moved by the arc-shaped extension rod 27, causing the flow diversion steel plate 25 to approach the control groove 26. At this time, the flow diversion steel plate 25, the control groove 26, the heat insulation chamber 3, and the notch on the lifting plate 41 are aligned. Therefore, when the heat insulation chamber 3 rises, the flow diversion steel plate 25 is separated from the heat insulation chamber 3 by cooperating with the steel pipe concrete column 5. Thus, when the heat insulation chamber 3 is ignited and baked inside, the flame is prevented from directly acting on the flow diversion steel plate 25.

[0069] To prevent conflicts between the explosion simulation mechanism and the secondary fire simulation mechanism, in practical applications, the steel-concrete composite column 5 is first hoisted onto the support platform 1 using hoisting equipment. Then, during the explosion simulation, explosive charges are first filled into the explosion chamber 22 through the filling hole 23. Next, the explosion-proof chamber 2 is lifted by tightening the steel cable 13, causing it to partially cover the steel-concrete composite column 5. At this point, under the influence of gravity, the lifting plate 41 inside the explosion-proof chamber 2 descends and seals the assembly slot 4. Therefore, during the explosion, the explosion only occurs inside the explosion-proof chamber 2. After the impact of the explosion stops, the hydraulic lifting cylinder 12 pushes... The insulated chamber 3 rises, and during the rise, the lifting plate 41 is lifted by the separation column 31 until the insulated chamber 3 covers the steel pipe concrete column 5 that has experienced the explosion. Then, the secondary fire simulation mechanism installed inside the insulated chamber 3 operates, using flames to bake the steel pipe concrete column 5 that has experienced the explosion. The flames are covered by the insulated chamber 3, preventing the flames from directly acting on the explosion simulation mechanism. At the same time, since there is no direct contact between the insulated chamber 3 and the explosion simulation mechanism (except for the connection between the insulated chamber 3 and the lifting plate 41 through the separation column 31), the high temperature has little impact on the explosion simulation mechanism as the heating and baking proceeds.

[0070] This invention connects the explosion-proof chamber 2 and the heat-insulating chamber 3 by interlocking them and by raising and lowering them. During the explosion simulation, this effectively reduces the probability of the heat-insulating chamber 3 being damaged by the explosion impact. In the secondary fire simulation, the heat-insulating chamber 3 limits the range of the flames and, by hindering the heat and by avoiding direct contact between the heat-insulating chamber 3 and the explosion simulation mechanism, effectively reduces the probability of the explosion simulation mechanism being damaged by high temperatures.

[0071] A method for testing the blast resistance of concrete-filled steel tubular columns, comprising the following steps:

[0072] S1: The steel-concrete composite column 5 sample is coaxially hoisted and installed onto the support platform 1. Simultaneously, the hatch 24 is opened, and the explosive cartridge is placed into the explosion chamber 22 through the filling hole 23.

[0073] S2: Continue to tighten the steel cable 13 to lift the explosion-proof chamber 2 until the bottom of the explosion-proof chamber 2 is higher than the top of the support platform 1, and the lifting plate 41 will descend by itself to seal the assembly slot 4.

[0074] S3: Adjust the length of the arc-shaped extension rod 27, push the position of the diversion steel plate 25 to change, adjust the area of ​​the explosion effect on the steel pipe concrete column 5, and then detonate the electronic detonator inside the explosive cartridge;

[0075] S4: After the explosion, the hydraulic lifting cylinder 12 is activated to push the heat insulation chamber 3 up until the bottom of the heat insulation chamber 3 is separated from the support platform 1, and the secondary fire simulation mechanism is activated to create a fire environment outside the steel pipe concrete column 5.

[0076] S5: After the secondary fire simulation ended, the insulation chamber 3 and the explosion-proof chamber 2 were lowered in sequence, and the parameters of the steel pipe concrete were observed and recorded.

[0077] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A blast test apparatus for a concrete filled steel tubular column, characterized by, The application relates to a steel pipe concrete column explosion simulation device. The device comprises a frame support system for fixing a steel pipe concrete column (5); a secondary fire simulation mechanism for simulating a fire environment outside the steel pipe concrete, which is composed of an ignition gun (61) and a combustible gas injection pipe (6) connected with a combustible gas supply device; and an explosion simulation mechanism for performing an explosion operation on the steel pipe concrete column (5), which comprises: an explosion chamber installed on the frame support system and covering the outside of the steel pipe concrete column (5); and a cartridge installed in the explosion chamber and provided with an electronic detonator. The explosion chamber comprises an explosion-proof chamber body (2), an explosion cavity (22) and a drainage steel plate (25). The explosion-proof chamber body (2) is a cylindrical cavity structure, the top end of the explosion-proof chamber body (2) is provided with a mounting groove (21), the steel pipe concrete column (5) is installed in the explosion-proof chamber body (2) through the mounting groove (21), and the steel pipe concrete column (5) is coaxially arranged with the explosion-proof chamber body (2). An explosion cavity (22) is arranged on the explosion-proof chamber body (2), a filling hole (23) is arranged on the explosion-proof chamber body (2), the filling hole (23) is in communication connection with the explosion cavity (22), the cartridge is installed in the explosion cavity (22) through the filling hole (23), and a hatch (24) is hingedly installed on the explosion-proof chamber body (2) and used for closing the filling hole (23). A vertically-arranged drainage steel plate (25) is installed in the explosion-proof chamber body (2) and used for guiding the airflow generated by explosion towards the steel pipe concrete column (5).

2. The blast test apparatus for a concrete filled steel tubular column according to claim 1, wherein: The explosion cavity (22) is annularly designed, the drainage steel plate (25) extends into the explosion cavity (22), a control groove (26) is formed on the side of the explosion-proof chamber body (2) away from the filling hole (23), an arc-shaped extension rod (27) is installed in the control groove (26), the arc-shaped extension rod (27) is an electric telescopic rod, the arc-shaped extension rod (27) extends into the explosion cavity (22), the arc-shaped extension rod (27) is connected with the drainage steel plate (25), and the arc-shaped extension rod (27) is used for adjusting the interval distance between two drainage steel plates (25). The end of the arc-shaped extension rod (27) is fixedly provided with a spring plate (28), and the arc-shaped extension rod (27) is elastically connected with the drainage steel plate (25) through the spring plate (28). The explosion cavity (22) is designed in plurality, and the explosion cavities (22) are uniformly arranged along the height direction of the explosion-proof chamber body (2), and the cross-section diameter of the explosion cavities (22) increases with the shortening of the distance from the steel pipe concrete column (5). A heat insulation chamber (3) is installed in the explosion-proof chamber body (2) and located between the explosion-proof chamber body (2) and the steel pipe concrete column (5), the heat insulation chamber (3) is made of heat insulation material, and the secondary fire simulation mechanism is installed on the inner side of the heat insulation chamber (3).

3. The blast test apparatus for a concrete filled steel tubular column according to claim 2, wherein: ​ 4. The blast test apparatus for a concrete filled steel tubular column according to claim 3, wherein: ​ 5. The blast test apparatus for a concrete filled steel tubular column according to claim 4, wherein: ​ 6. The blast test apparatus for a concrete filled steel tubular column according to claim 5, wherein: ​ 7. The blast test apparatus for a concrete filled steel tubular column according to claim 6, wherein: The frame support system is composed of a support table (1) and a hoisting frame (11), the hoisting frame (11) is a frame structure with an open top, the support table (1) is fixedly installed in the middle of the hoisting frame (11), the explosion-proof cabin (2) is hoisted inside the hoisting frame (11) through a steel cable (13), the explosion-proof cabin (2) is located directly above the support table (1), an assembly slot (4) is formed in the bottom end of the explosion-proof cabin (2), the heat insulation cabin (3) is slidably sleeved on the support table (1) and the concrete-filled steel tubular column (5), a hydraulic lifting cylinder (12) is installed at the bottom of the heat insulation cabin (3), and the heat insulation cabin (3) enters and exits the explosion-proof cabin through the assembly slot (4).

8. The blast test apparatus for a concrete filled steel tubular column according to claim 7, wherein: The explosion-proof cabin (2) is slidably installed with a lifting plate (41), the outer diameter of the lifting plate (41) is greater than the diameter of the assembly slot (4), the inner diameter of the lifting plate (41) is matched with the outer diameter of the concrete-filled steel tubular column (5), the heat insulation cabin (3) is an incomplete cylindrical structure, and the lifting plate (41) is an incomplete annular structure, and both of them are provided with notches in the circumferential direction, and the total width of the drainage steel plate (25) and the assembly slot (4) is less than the width of the notches after the drainage steel plate (25) is assembled close to the assembly slot (4).

9. The blast test apparatus for a concrete filled steel tubular column according to claim 8, wherein: The diameter of the heat insulation cabin (3) is less than the diameter of the assembly slot (4), a separation column (31) is installed at the top end of the heat insulation cabin (3), and the separation column (31) separates the lifting plate (41) from the heat insulation cabin (3).

10. A method for testing the blast resistance of concrete-filled steel tubular columns, characterized in that: The method uses the concrete-filled steel tubular column explosion resistance test device of claim 9, and the method comprises the following steps: S1: coaxially hoisting and installing the concrete-filled steel tubular column (5) sample to the support table (1), simultaneously opening the hatch (24), and placing the cartridge in the explosion chamber (22) through the filling hole (23); S2: continuously tightening the steel cable (13), hoisting the explosion-proof cabin (2), until the bottom end of the explosion-proof cabin (2) is higher than the top end of the support table (1), and the lifting plate (41) automatically descends to block the assembly slot (4); S3: adjusting the length of the arc-shaped extension rod (27), pushing the drainage steel plate (25) to change the position, adjusting the area on which the explosion acts on the concrete-filled steel tubular column (5), and then detonating the electronic detonator inside the cartridge; S4: after the explosion is completed, starting the hydraulic lifting cylinder (12), pushing the heat insulation cabin (3) to rise, until the bottom end of the heat insulation cabin (3) is separated from the support table (1), starting the secondary fire simulation mechanism, and creating a fire environment outside the concrete-filled steel tubular column (5); S5: after the secondary fire simulation is completed, the heat insulation cabin (3) and the explosion-proof cabin (2) are controlled to descend in sequence, and the parameters of the concrete-filled steel tubular column are observed and recorded.

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