A test device for civil structures subjected to lateral impact and explosion under service load

Abstract

The present application relates to a kind of test devices that civil structure under service load encounters lateral impact and causes explosion, the left and right sides of protective box are respectively provided with fixed support and movable support, fixed support and movable support are fixed with test piece between them;Explosion initiation assembly is arranged at the top of protective box, and explosion initiation assembly is connected with explosive at the bottom of protective box;After the impact end of impact assembly downwardly impacts explosion initiation assembly, explosion initiation assembly downwardly impacts test piece and triggers explosive explosion;Axial load loading assembly is connected with movable support, and axial load assembly applies axial load to test piece by movable support;Data acquisition assembly includes acquisition sensor and camera unit, acquisition sensor is arranged on test piece, and camera unit is arranged outside protective box and is used to shoot the deformation process of test piece.The present application has reasonable structure design, so that test can be carried out in laboratory, and it has important significance for the performance of structure under the action of impact-induced explosion.

Description

TECHNICAL FIELD

[0002] The application belongs to the technical field of engineering structure test, and particularly relates to a test device for a civil structure subjected to a transverse impact and explosion under service load. BACKGROUND

[0004] Civil structures will inevitably be subjected to an impact and explosion during their service life. For example, a bridge pier is subjected to an explosion caused by a vehicle-ship impact. Once the bridge, as an important component of a traffic lifeline engineering, is subjected to damage and even collapse, a regional traffic connection will be directly interrupted, and a series of negative chain effects such as material transportation delay, influence on the transportation of the wounded and aggravation of the disaster development will be caused, resulting in a loss of social economy. However, for a long time, the impact and explosion effect can only be researched by means of numerical simulation, and a key means of civil engineering research, i.e., a structure test, is lacked, so that the mechanical properties of the structure under the working condition of the transverse impact, explosion impact and coupling effect of high temperature caused by the explosion cannot be directly observed and the mechanical property indexes cannot be obtained, resulting in that the research results lack a verification means and have insufficient reliability. Therefore, it is necessary to provide a test device for a structure member subjected to a transverse impact and explosion under service load which can be safely carried out in a laboratory. SUMMARY

[0006] The application improves the prior art, and the technical problem to be solved by the application is to provide a test device for a civil structure subjected to a transverse impact and explosion under service load, which is reasonable in design and can more truly reflect a load working condition of the structure subjected to a transverse impact and explosion.

[0007] In order to achieve the above object, the application adopts the technical scheme of a test device for a civil structure subjected to a transverse impact and explosion under service load, which comprises an impact assembly, a protective box body, an axial load loading assembly, an explosion initiation assembly and a data acquisition assembly. The left and right sides of the protective box body are respectively provided with fixed supports and movable supports, and a test piece is fixed between the fixed supports and the movable supports and penetrates the protective box body in the transverse direction. The explosion initiation assembly is arranged at the top of the protective box body and is connected with explosives arranged at the bottom of the protective box body. The impact assembly is arranged above the protective box body. When the impact end of the impact assembly impacts the explosion initiation assembly downward, the explosion initiation assembly impacts the test piece downward and triggers the explosion of the explosives. The axial load loading assembly is connected with the movable supports, and the axial load assembly applies an axial load to the test piece through the movable supports. The data acquisition assembly comprises an acquisition sensor and a camera unit. The acquisition sensor is arranged on the test piece, and the camera unit is arranged outside the protective box body and is used for shooting the deformation process of the test piece.

[0008] Further, the axial load loading assembly comprises a plurality of loading rods distributed outside the protection box and arranged transversely, left and right ends of the loading rods are respectively slid through fixed supports and movable supports, the fixed supports are provided with driving members for driving the loading rods to move transversely, and elastic members capable of deforming transversely are arranged between the movable supports and the right ends of the loading rods.

[0009] Further, the driving members comprise a plurality of oil pump jacks corresponding to positions of the loading rods, the oil pump jacks are arranged transversely, and telescopic ends of the oil pump jacks are extended to the left and connected with the left ends of the loading rods; the elastic members comprise a plurality of disc springs corresponding to positions of the loading rods, the disc springs are sleeved outside the right ends of the loading rods, right ends of the disc springs are connected with the loading rods, and left ends of the disc springs are connected with right side surfaces of the movable supports.

[0010] Further, the fixed supports are fixed on the rigid platform, and the movable supports are in transverse sliding fit with the rigid platform through transverse sliding members.

[0011] Further, a vertical through hole is formed in a middle portion of a top surface of the protection box; the explosion initiation assembly comprises an impact conversion head, an explosion initiator and an explosive lead, a lower end of the explosive lead is connected with the explosive, and an upper end of the explosive lead is connected with the explosion initiator arranged on the explosion face of the test piece; the impact conversion head is arranged in the vertical through hole and corresponds to the impact end of the impact assembly, a trigger rod for contacting the explosion initiator is fixed on a lower end side wall of the impact conversion head, and when the impact conversion head is impacted by the impact end of the impact assembly and moves downward, the trigger rod contacts the explosion initiator.

[0012] Further, a plurality of vertical buckles are connected between a side wall of the vertical through hole and a circumferential side wall of the impact conversion head, and a plurality of pulley blocks distributed vertically are arranged on the side wall of the vertical through hole, and the circumferential side wall of the impact conversion head is provided with vertical sliding rails corresponding to positions of the pulley blocks, and when the impact conversion head moves downward, the vertical sliding rails are in sliding fit with the pulley blocks.

[0013] Further, the protection box is made of a plurality of protection plates and has a cuboid shape, and the protection plates comprise, from outside to inside, an outer steel plate, concrete, an inner steel plate and an asbestos plate.

[0014] Further, the front and rear side walls of the protective box are provided with shooting windows, and explosion-proof glass is installed in the shooting windows; the camera unit comprises a pair of front and rear distributed high-speed cameras, the high-speed cameras are installed on the camera support, and the high-speed cameras are opposite to the shooting windows; the collection sensor comprises an acceleration sensor, an overpressure sensor and a thermocouple, the overpressure sensor is arranged on the blast-facing surface of the test piece, the acceleration sensor is arranged on the blast-backing surface of the test piece, and the thermocouple is arranged on the surface of the test piece.

[0015] Further, the impact assembly is a drop hammer type impact testing machine, the drop hammer type impact testing machine comprises a testing machine frame, a pair of steel rail slides vertically arranged in the testing machine frame, and a drop hammer in sliding cooperation with the steel rail slides, a winch is installed at the top of the testing machine frame, the winding end of the winch is connected with the drop hammer through a steel wire rope, and the winch is controlled by an electromagnetic valve; a counterweight is installed at the upper end of the drop hammer.

[0016] Another technical solution of the application is a test method for explosion caused by transverse impact of civil structures under service load, comprising the following steps:

[0017] Step S1: the acceleration sensor is arranged on the blast-backing surface of the test piece, and the acceleration sensor is fixed through a steel base welded on the outer steel pipe of the test piece; the overpressure sensor is arranged on the blast-facing surface of the test piece; and the thermocouple is fixed on the surface of the test piece.

[0018] Step S2: the two ends of the test piece are respectively inserted through the left and right side walls of the protective box, the left end of the test piece is fixed on the right side of the fixed support through bolts, and the test piece is supported and placed horizontally; then the movable support is moved, and the right end of the test piece is fixed on the left side of the movable support through bolts;

[0019] Step S3: the explosion initiator is fixed on the blast-backing surface of the test piece, and the explosive and the explosion initiator are connected through an explosive fuse;

[0020] Step S4: assemble the protective box;

[0021] Step S5: the high-speed camera frame is arranged on the camera support on the front and rear sides of the protective box, and the high-speed camera performs real-time shooting through the explosion-proof glass;

[0022] Step S6: start the oil pump jack, the oil pump jack drives the loading rod to move to the left side, the loading rod applies an axial load to the movable support and the test piece through the disc spring, and the disc spring is in a compressed state to store elastic potential energy;

[0023] Step S7: the winch hoists the drop hammer, and then the winch is powered off and the drop hammer is released by the electromagnetic valve, the drop hammer hits the impact conversion head downward, hits the vertical buckle, and at the same time, kinetic energy is transmitted to the impact conversion head, the impact conversion head slides down the pulley set and acts on the test piece, the process of the impact conversion head falling is triggered by the trigger lever to trigger the explosion initiator to cause explosion; at the same time, the acceleration sensor, the overpressure sensor and the thermocouple collect the acceleration response of the test piece, the explosion shock wave and the surface temperature of the test piece respectively, and the whole process deformation of the test piece is recorded by the high-speed camera.

[0024] Compared with the prior art, the present application has the following effects: the structure design of the present application is reasonable, the test can be carried out in the laboratory while simulating the impact and explosion, which has important significance for studying the performance of the structure under the action of impact-induced explosion. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a front view structural schematic diagram of the embodiment of the present application;

[0027] Figure 2 is Figure 1 is a structural schematic diagram of the front end of the protective box body in the embodiment of the present application;

[0028] Figure 3 is a left view structural schematic diagram in the embodiment of the present application;

[0029] Figure 4 is a right view structural schematic diagram in the embodiment of the present application;

[0030] Figure 5 is a three-dimensional structural schematic diagram of the protective box body in the embodiment of the present application;

[0031] Figure 6 is a structural schematic diagram of the protective plate in the embodiment of the present application;

[0032] Figure 7 is a sectional structural schematic diagram of the protective plate in the embodiment of the present application;

[0033] Figure 8 is a structural schematic diagram of the impact conversion head in the embodiment of the present application;

[0034] Figure 9 is a structural schematic diagram of the explosion initiation assembly in the embodiment of the present application.

[0035] In the drawings:

[0036] 1-rigid beam; 2-lattice steel column; 3-rail slide; 4-counterweight; 5-drop hammer; 6-oil pump jack; 7-disc spring; 8-loading rod; 10-fixed support; 11-movable support; 12-ground anchor bolt; 13-protection box; 131-outer steel plate; 132-concrete; 133-inner steel plate; 134-asbestos plate; 14-high-strength bolt; 15-high-speed camera; 16-camera support; 17-test piece; 18-bolt; 19-acceleration sensor; 20-overpressure sensor; 21-thermocouple; 22-explosion initiator; 23-explosive fuse; 24-explosive; 25-impact conversion head; 251-vertical buckle; 252-pulley block; 253-trigger lever; 26-explosion-proof glass; 27-shooting window; 28-transverse through hole; 29-protection plate; 30-drop hammer impact testing machine; 31-vertical column; 32-vertical through hole; 33-fixed clamping rod; 34-clamping convex part; 35-movable clamping rod; 36-clamping groove; 37-pulley block; 38-vertical slide rail. DETAILED DESCRIPTION

[0038] The application will be further described below in conjunction with the drawings and specific embodiments.

[0039] In the description of the present application, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0040] As Figures 1-9As shown, the application is a test device for civil structure under service load encountering lateral impact and explosion, which comprises an impact assembly, a protective box 13, an axial load loading assembly, an explosion initiation assembly and a data acquisition assembly, the left and right sides of the protective box 13 are respectively provided with a fixed support 10 and a movable support 11, the fixed support 10 and the movable support 11 are fixed with a test piece 17 penetrating the protective box 13 in the transverse direction through bolts; the explosion initiation assembly is arranged at the top of the protective box 13, and the explosion initiation assembly is connected with the explosive 24 arranged at the bottom of the protective box 13; the impact assembly is arranged above the protective box 13, when the impact end of the impact assembly impacts downward on the explosion initiation assembly, the explosion initiation assembly impacts downward on the test piece 17 and triggers the explosive explosion; the axial load loading assembly is connected with the movable support 11, and the axial load assembly applies axial load to the test piece 17 through the movable support 11; the data acquisition assembly comprises an acquisition sensor and a camera unit, the acquisition sensor is arranged on the test piece, and the camera unit is arranged outside the protective box 13 and is used for shooting the deformation process of the test piece under explosion.

[0041] In this example, the impact assembly is a drop hammer impact testing machine 30, which is used to convert the potential energy of the drop hammer into kinetic energy to apply impact load. The drop hammer impact testing machine 30 comprises a testing machine frame, a pair of steel rail slides 3 arranged vertically inside the testing machine frame, and a drop hammer 5 in sliding fit with the steel rail slides 3. The top of the testing machine frame is provided with a winch (not shown in the figure), the winding end of the winch is connected with the drop hammer 5 through a steel wire rope, the drop hammer 5 is arranged between the pair of steel rail slides 3, and the winch pulls the drop hammer 5 to move downward along the steel rail slides 3 through the steel wire rope. The winch is controlled by an electromagnetic valve, and the winch is de-energized by the electromagnetic valve control, at which time the drop hammer can drop downward along the steel rail slide under the action of gravity, which is convenient, safe and reliable to operate.

[0042] In this example, the upper end of the drop hammer 5 is provided with a counterweight 4, and the mass of the drop hammer 5 can be adjusted within a certain range by changing the mass of the counterweight 4, which is matched with different heights to meet different impact performance requirements.

[0043] In this example, the testing machine frame is a portal steel frame composed of a rigid cross beam 1 and a vertical lattice steel column 2, and vertical columns 31 are fixed at the top corners of the bottom surface of the rigid cross beam 1.

[0044] In the embodiment, the axial load loading assembly is used for applying and maintaining the service load of the structure, which comprises six loading rods 8 distributed on the front and rear sides of the protection box 13 and arranged transversely, the left and right ends of the loading rod 8 are respectively slid through the fixed support 10 and the movable support 11, the fixed support 10 is provided with a driving member for driving the loading rod 8 to move transversely, and the right end of the loading rod 8 and the movable support 11 are provided with an elastic member which can be deformed transversely, when the driving member drives the loading rod 8 to move transversely to the left, the elastic member is in a compressed state and stores elastic potential energy, and the elastic member applies an axial load on the test piece through the movable support.

[0045] In the embodiment, the driving member comprises six oil pump jacks 6 corresponding to the positions of the six loading rods, the oil pump jacks 6 are arranged transversely, the telescopic ends of the oil pump jacks 6 are extended to the left and connected with the left ends of the loading rods 8 corresponding in position, the oil pump jacks 6 drive the loading rods 8 to move transversely left and right, so as to apply the axial force required by the test; the elastic member comprises six disc springs 7 corresponding to the positions of the six loading rods 8, the disc springs 7 are arranged transversely, the disc springs 7 are sleeved outside the right ends of the loading rods 8, the right ends of the disc springs 7 are connected with the loading rods 8, and the left ends of the disc springs 7 abut against the right side surface of the movable support 11, when the oil pump jacks 6 drive the loading rods 8 to move transversely to the left, the loading rods 8 compress the disc springs 7, and the disc springs apply an axial load on the test piece through the movable support.

[0046] In the embodiment, the lower end of the fixed support 10 is fixed on a rigid platform (not shown in the figure) through a ground anchor bolt 12, and the movable support 11 is slidably connected with the rigid platform transversely. Preferably, the transverse sliding member is a linear bearing arranged transversely, which can constrain the displacement of the test piece in all directions except the axial direction, so that the support realizes the boundary condition of clamping support.

[0047] In the embodiment, during the impact process, the test piece 17 is rapidly shortened in the axial direction due to the deflection, at the moment when the test piece 17 is shortened along the axis, the disc spring 7 releases the elastic potential energy stored in it in advance, so that the axial force continues to be loaded on the test piece 17, and in this process, the problem of partial unloading of the axial force can be solved by selecting appropriate number of springs.

[0048] In the embodiment, the protective box 13 is provided with transverse through holes 28 in the middle of the left and right ends of the protective box 13 for facilitating the penetration of the test piece 17, and the protective box 13 is provided with a vertical through hole 32 in the middle of the top surface of the protective box 13, and the front and rear side walls of the protective box 13 are provided with shooting windows 30, and the shooting windows 30 are provided with explosion-proof glass 26. Further, the protective box 13 is made of multiple protective plates 29 and has a cuboid shape, and the protective plate 29 includes an outer steel plate 131, concrete 132, an inner steel plate 133 and an asbestos plate 134 arranged from outside to inside. The protective plate adopts a double-layer steel plate filled with concrete structure, has good impact resistance and energy absorption capacity; the asbestos plate 134 is arranged on the inner steel plate 133 to avoid the influence of high temperature caused by explosion on surrounding equipment and personnel. It should be noted that the protective box is assembled by high-strength bolts, and has the advantages of convenient disassembly and assembly when carrying out large-scale structure test.

[0049] In the embodiment, the explosion initiation assembly includes an impact conversion head 25, an explosion initiator 22 and an explosive lead 23, the lower end of the explosive lead 23 is connected with the explosive 24, and the upper end of the explosive lead 23 is connected with the explosion initiator 22 arranged on the back explosion surface of the test piece 17; the impact conversion head 25 is arranged in the vertical through hole 32 and corresponds to the drop hammer 5 of the drop hammer impact testing machine, and the lower end side wall of the impact conversion head 25 is fixed with a trigger rod 253 for contacting the explosion initiator 22, when the impact conversion head 25 is impacted by the drop hammer 5 and moves downward, the impact conversion head 25 applies an impact action to the test piece 17, and the explosion is initiated at the moment when the trigger rod 253 contacts the explosion initiator 22, so that the test piece 17 simultaneously suffers the combined action of transverse impact action, explosion shock wave and explosion high temperature. By arranging the vertical through hole in the middle of the top surface of the protective box and arranging the impact conversion head in the vertical through hole, the damage of explosion to the drop hammer 5 can be prevented.

[0050] In the embodiment, the vertical through hole 32 is connected with the circumferential side wall of the impact conversion head 25 by four vertical buckles arranged in a circumferential direction, the impact conversion head 25 moves downward under the impact of the drop hammer, so that the vertical buckles are separated, the vertical buckles include a fixed clamping rod 33 and a movable clamping rod 35, the fixed clamping rod 33 is fixedly installed on the side wall of the vertical through hole 32, and the upper end of the fixed clamping rod 33 is provided with an arc-shaped clamping convex part 34; the movable clamping rod 35 is L-shaped and is fixed to the outer side wall of the impact conversion head 25, and the vertical section of the movable clamping rod 35 is provided with an arc-shaped clamping recess 36, and the clamping recess 36 is used for cooperating with the clamping convex part 34. Preferably, the fixed clamping rod is welded on the outer steel plate 131 and the inner steel plate 133 of the protective plate.

[0051] In the embodiment, the side wall of the vertical through hole 32 is further provided with four vertically distributed pulley sets 37, the four pulley sets 37 are circumferentially distributed, and the circumferential side wall of the impact conversion head 25 is provided with vertical sliding rails 38 corresponding to the positions of the four pulley sets 37. When the impact conversion head moves downward, the vertical sliding rails 38 slide with the pulley sets 37 to guide the vertical movement of the impact conversion head. By arranging the vertical buckles and the pulley sets, the impact conversion head is temporarily fixed in the vertical through hole through the vertical buckles. When the drop hammer falls on the impact conversion head, the kinetic energy converted from the potential energy of the drop hammer is transferred to the impact conversion head, forcing the impact conversion head to push away the vertical buckles and move downward along the pulley sets. At the same time of impacting the test piece, the explosion initiator is triggered by the trigger rod to cause an explosion, so that the test piece is subjected to the combined action of the lateral impact, the explosion shock wave and the high temperature of the explosion.

[0052] In the embodiment, the camera unit includes a pair of front and rear distributed high-speed cameras 15, the high-speed cameras 15 are installed on the camera bracket 16, the high-speed cameras 15 are opposite to the shooting window 27, and the high-speed cameras 15 perform real-time shooting through the explosion-proof glass 26 of the protection box 13 to record the test phenomena in the whole process of the formation, propagation and structural interaction of the shock wave, so as to realize the collection of test related data. The collection sensor includes an acceleration sensor, an overpressure sensor and a thermocouple. In order to measure the distribution characteristics of the explosion load, the overpressure sensor is arranged on the explosion-facing surface of the test piece (i.e. the side surface facing the explosive). The acceleration sensor is arranged on the explosion-backing surface of the test piece (i.e. the side surface away from the explosive) to measure the dynamic response of the test piece under the explosion action, and to avoid the acceleration sensor 19 from falling off or being damaged under the action of the explosion shock wave. Preferably, the acceleration sensor 19 is fixed by a steel base welded on the outer steel pipe of the test piece. The thermocouple is arranged on the surface of the test piece to measure the high temperature caused by the explosion.

[0053] In the embodiment, the test method for the civil structure subjected to lateral impact and explosion under service load includes the following steps.

[0054] Step S1, installing the acceleration sensor 19, the overpressure sensor 20 and the thermocouple 21: arranging the acceleration sensor 19 on the explosion-backing surface of the test piece 17, and fixing the acceleration sensor 19 by a steel base welded on the outer steel pipe of the test piece 17; arranging the overpressure sensor 20 on the explosion-facing surface of the test piece 17; fixing the thermocouple 21 on the surface of the test piece 17;

[0055] Step S2, installing the test piece 17: passing the left and right ends of the test piece 17 through the left and right side walls of the protection box 13 respectively, fixing the left end of the test piece 17 on the right side surface of the fixed support 10 through the bolt 18, supporting the test piece 17 and keeping it horizontally placed; then moving the movable support 11, fixing the right end of the test piece 17 on the left side surface of the movable support 11 through the bolt.

[0056] Step S3, installing explosion initiation assembly: fixing the explosion initiator 22 on the back explosion surface of the test piece 17, connecting the explosive and the explosion initiator 22 with the explosive fuse 23;

[0057] Step S4, installing protective box: assembling the protective box 13 and fixing it by using high-strength bolts 14;

[0058] Step S5, arranging high-speed cameras 15: arranging the high-speed cameras 15 on the front and back sides of the protective box 13 through the camera support 16, and the high-speed cameras 15 are used for real-time shooting through the explosion-proof glass 26;

[0059] Step S6, applying axial load: starting the oil pump jack 6, the oil pump jack 6 drives the loading rod 8 to move to the left side, the loading rod 8 applies an axial load to the movable support 11 and the test piece 17 through the disc spring 7, and the disc spring 7 is in a compressed state to store elastic potential energy;

[0060] Step S7, implementing impact initiation explosion test: lifting the drop hammer 5 by the winch, then controlling the winch to be powered off and releasing the drop hammer through the electromagnetic valve, the drop hammer hits the impact conversion head 25 downward, the vertical buckle is hit open, and kinetic energy is transmitted to the impact conversion head 25, the impact conversion head 25 slides down along the pulley set 37 and acts on the test piece 17, the process of the impact conversion head 25 falling is used for triggering the explosion initiator 22 through the trigger rod, and explosion is initiated; at the same time, the acceleration response of the test piece 17, the explosion shock wave and the surface temperature of the test piece are collected through the acceleration sensor 19, the overpressure sensor 20 and the thermocouple 21 respectively, and the whole process deformation of the test piece is recorded through the high-speed camera.

[0061] If the present application discloses or involves parts or structural members fixedly connected with each other, unless otherwise stated, the fixed connection can be understood as: detachable fixed connection (for example, connected by using bolts or screws), and can also be understood as: non-detachable fixed connection (for example, riveting, welding), of course, the fixed connection with each other can also be replaced by an integral structure (for example, manufactured by integral forming process, except that integral forming process is obviously unavailable).

[0062] In addition, the terms used to represent the position relationship or shape in any of the technical solutions disclosed in the present application include the approximate, similar or close state or shape, unless otherwise stated.

[0063] Any component provided by the present application can be assembled from multiple individual components, or can be a single component manufactured by integral forming process.

[0064] It should be pointed out finally that the above examples are only used to illustrate the technical solutions of the present application but not to limit it; although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the specific embodiments of the present application can be modified or some technical features can be replaced by equivalent ones without departing from the spirit of the technical solutions of the present application, and all of them should be covered in the technical solution range claimed by the present application.

Claims

1. A test apparatus for testing the explosion of a civil structure under service load due to a lateral impact, characterized in that: The impact assembly, the protective box, the axial load loading assembly, the explosion initiation assembly and the data acquisition assembly are included, the left and right sides of the protective box are respectively provided with fixed supports and movable supports, the test piece is fixed between the fixed supports and the movable supports and penetrates the protective box along the transverse direction, the explosion initiation assembly is arranged on the top of the protective box and is connected with the explosive arranged on the bottom of the protective box, the impact assembly is arranged above the protective box, when the impact end of the impact assembly impacts the explosion initiation assembly downwards, the explosion initiation assembly impacts the test piece downwards and triggers the explosive explosion, the axial load loading assembly is connected with the movable support, the axial load assembly applies the axial load to the test piece through the movable support, the data acquisition assembly includes the acquisition sensor and the camera unit, the acquisition sensor is arranged on the test piece, and the camera unit is arranged outside the protective box and is used for shooting the deformation process of the test piece. A vertical through hole is arranged in the middle of the top surface of the protective box, the explosion initiation assembly includes the impact conversion head, the explosion initiator and the explosive lead, the lower end of the explosive lead is connected with the explosive, the upper end of the explosive lead is connected with the explosion initiator arranged on the back explosion surface of the test piece, the impact conversion head is arranged in the vertical through hole and corresponds to the impact end of the impact assembly, the lower end side wall of the impact conversion head is fixed with the trigger rod used for contacting the explosion initiator, when the impact conversion head is impacted by the impact end of the impact assembly and moves downwards, the trigger rod contacts the explosion initiator. A plurality of vertical buckles are connected between the side wall of the vertical through hole and the circumferential side wall of the impact conversion head, a plurality of vertical pulley blocks are arranged on the side wall of the vertical through hole in the vertical direction, and the circumferential side wall of the impact conversion head is provided with vertical sliding rails corresponding to the positions of the plurality of pulley blocks, when the impact conversion head moves downwards, the vertical sliding rails and the pulley blocks are in sliding cooperation.

2. The test apparatus for a civil structure subjected to a lateral impact and explosion induced by a service load according to claim 1, characterized in that: The axial load loading assembly includes a plurality of loading rods distributed outside the protective box and arranged in the transverse direction, the left and right ends of the loading rods are respectively slidably penetrated through the fixed supports and the movable supports, the fixed supports are provided with driving members for driving the loading rods to move in the transverse direction, and the movable supports and the right ends of the loading rods are provided with elastic members which can be deformed in the transverse direction, when the driving members drive the loading rods to move in the transverse direction to the left, the elastic members are in a compressed state.

3. The test apparatus for a civil structure subjected to a lateral impact and explosion induced by a service load according to claim 2, characterized in that: The driving members include a plurality of oil pump jacks corresponding to the positions of the plurality of loading rods, the oil pump jacks are arranged in the transverse direction, the telescopic ends of the oil pump jacks extend to the left and are connected with the left ends of the loading rods, the elastic members include a plurality of disc springs corresponding to the positions of the plurality of loading rods, the disc springs are sleeved outside the right ends of the loading rods, the right ends of the disc springs are connected with the loading rods, and the left ends of the disc springs are connected with the right side surfaces of the movable supports.

4. The test apparatus for a civil structure subjected to a lateral impact and explosion induced by a service load according to claim 3, characterized in that: The fixed supports are fixed on the rigid platform, and the movable supports are in transverse sliding cooperation with the rigid platform through the transverse sliding members.

5. The test apparatus for simulating an explosion of a civil structure subjected to a lateral impact under a service load according to claim 4, characterized in that: The protective box is made of a plurality of protective plates and has a cuboid shape, and the protective plates include an outer steel plate, concrete, an inner steel plate and an asbestos plate arranged in sequence from outside to inside.

6. The test apparatus for a civil structure subjected to a lateral impact induced explosion under a service load according to claim 5, characterized in that: The front and rear side walls of the protective box are provided with shooting windows, and explosion-proof glass is installed in the shooting windows; the camera unit comprises a pair of front and rear distributed high-speed cameras, the high-speed cameras are installed on camera supports, and the high-speed cameras are opposite to the shooting windows; the collection sensor comprises an acceleration sensor, an overpressure sensor and a thermocouple, the overpressure sensor is arranged on the blast-facing surface of the test piece, the acceleration sensor is arranged on the blast-backing surface of the test piece, and the thermocouple is arranged on the surface of the test piece.

7. The test apparatus for simulating an explosion of a civil structure subjected to a lateral impact under a service load according to claim 6, wherein: The impact assembly is a drop hammer type impact testing machine, the drop hammer type impact testing machine comprises a testing machine frame, a pair of steel rail slides vertically arranged in the testing machine frame, and a drop hammer in sliding cooperation with the steel rail slides, a winch is installed on the top of the testing machine frame, the winding end of the winch is connected with the drop hammer through a steel wire rope, and the winch is controlled by an electromagnetic valve; a counterweight is installed on the upper end of the drop hammer.

8. A method for testing a civil structure subjected to a lateral impact causing an explosion under a service load, characterized by: The method comprises the following steps: Step S1: the acceleration sensor is arranged on the blast-backing surface of the test piece, and the acceleration sensor is fixed by a steel base welded on the outer steel pipe of the test piece; the overpressure sensor is arranged on the blast-facing surface of the test piece; and the thermocouple is fixed on the surface of the test piece; Step S2: the two ends of the test piece are respectively passed through the left and right side walls of the protective box, the left end of the test piece is fixed on the right side of the fixed support through bolts, and the test piece is supported and placed horizontally; then the movable support is moved, and the right end of the test piece is fixed on the left side of the movable support through bolts; Step S3: the explosion initiator is fixed on the blast-backing surface of the test piece, and the explosive lead is connected with the explosive and the explosion initiator; Step S4: the protective box is assembled; Step S5: the high-speed camera frame is arranged on the camera support on the front and rear sides of the protective box, and the high-speed camera performs real-time shooting through the explosion-proof glass; Step S6: the oil pump jack is started, the oil pump jack drives the loading rod to move to the left, the loading rod applies an axial load to the movable support and the test piece through the disc spring, and the disc spring is in a compressed state to store elastic potential energy; Step S7: the winch lifts the drop hammer, then the winch is controlled to be powered off through the electromagnetic valve and the drop hammer is released, the drop hammer impacts the impact conversion head downward, the vertical buckle is knocked off, the kinetic energy is transmitted to the impact conversion head, the impact conversion head slides down along the pulley set and acts on the test piece, the process of the impact conversion head falling is used to trigger the explosion initiator through the trigger rod to cause explosion; meanwhile, the acceleration response of the test piece, the explosion shock wave and the surface temperature of the test piece are collected through the acceleration sensor, the overpressure sensor and the thermocouple respectively, and the whole process deformation of the test piece is recorded through the high-speed camera.

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