A device adapted for earthquake impact sequence action test and its use method

Abstract

The present invention discloses a device adapted for earthquake impact sequence action test and its use method, the test device includes a support assembly, an anti-jump assembly, an axial force assembly and a drop hammer assembly; the support assembly is composed of two counterweight boxes and a connecting beam, and the counterweight boxes are fixed to both sides of the test bench base through the connecting beam with an adjustable spacing; the anti-jump assembly includes a limit column pre-embedded in the counterweight box and a height-adjustable transverse constraint beam for limiting the displacement of the model end; the axial force assembly is provided at both ends of the model, including an axial force block, a tie rod and an axial force application mechanism, forming a closed-loop axial force transmission system; the drop hammer assembly includes a slide rail, a drop hammer with adjustable counterweight and a hammer head, and the drop hammer is slidably connected to the slide rail. The present invention can adapt to models of different sizes, match the special-shaped bridge pier model with a large lower end and a small upper end after the vibration table test, and break through the limitation of the traditional drop hammer device on the model size; at the same time, it simulates the fixed connection of the bottom of the model and the hinge of the top of the model, thereby increasing the accuracy of the simulation test.

Description

Technical Field

[0001] The present invention belongs to the technical field of earthquake disaster chain simulation test, and specifically relates to a device adapted for earthquake impact sequence action test and a method for using the device. Background Art

[0002] Earthquakes not only directly damage bridge structures but can also trigger chain reactions of secondary disasters in mountainous areas, such as landslides, rockfalls, and debris flows, and on roads, vehicles losing control and colliding with bridge piers. In mountainous areas, strong earthquakes can loosen the mountain's rock formations, generating a large number of sharp-edged rocks. They also alter the terrain and flow conditions, making post-earthquake debris flows faster and more powerful. On roads, earthquake-induced road damage and vehicle loss of control can very likely cause vehicles to collide with bridge piers. More critically, earthquake shaking and subsequent impacts can simultaneously affect bridge structures, creating a "damage cascade effect" that accelerates pier failure. Therefore, studying the coupled damage process of earthquakes and impacts is crucial for bridge disaster prevention.

[0003] An important means of studying the coupling effect of earthquakes and shocks is to use the method of scaled earthquake shock sequence test to objectively and intuitively present the changes of component models under the coupling effect of earthquakes and shocks. At present, researchers mainly simulate disasters through two types of independent tests:

[0004] Vibration table test: Figure 7 and Figure 8 As shown in the figure, the shaking table test platform uses hydraulic or electric servo-driven actuators to provide push or pull force to the table surface to control the movement of the table surface, thereby simulating the shaking damage to the bridge caused by an earthquake. However, this device can only provide acceleration generated by the bottom and cannot reproduce the impact process.

[0005] Drop hammer impact test: By adjusting the shape and mass of the drop hammer of the drop hammer test platform, the instantaneous damage caused by stones of different shapes and masses hitting the bridge piers is simulated. However, it cannot provide bottom acceleration to the components and cannot produce damage caused in advance by an earthquake.

[0006] The core defects of the existing technology are:

[0007] 1. The shaking table test and drop hammer test need to be carried out on different models respectively, which makes it impossible to continuously simulate the disaster chain of "earthquake damage-secondary impact" on the same specimen, and it is impossible to conduct earthquake impact sequence action tests, making it difficult to reveal the coupling mechanism of damage accumulation and impact destruction in real disasters.

[0008] 2. Conventional shake tables and drop hammer impact platforms are both standardized, and no drop hammer impact platform is perfectly adapted to the size of the shake table model. Bridge pier models for shake table tests are typically designed as a trapezoidal structure, narrow at the top and wide at the bottom (the bottom must be securely mounted on the shake table). Traditional drop hammer devices require the model to be of identical dimensions at both ends for stable mounting. Therefore, a single model cannot meet the installation requirements of both tests.

[0009] 3. Conventional drop-weight test bench bases are designed for small specimens, whereas bridge pier models used in seismic testing often reach heights exceeding two meters. Existing equipment is unable to secure large, irregularly shaped models and lacks adjustment capabilities. Consequently, many organizations possess both types of equipment but are unable to use them together due to the mismatch in size, resulting in idle resources.

[0010] These defects have made it difficult for the scientific community to truly reproduce the complete destructive process of the earthquake disaster chain for a long time, and have also restricted the comprehensive utilization efficiency of large-scale test equipment. Summary of the Invention

[0011] The main purpose of the present invention is to provide a device and a method for using the device for adapting to earthquake impact sequence action test, which can reproduce the entire process of "earthquake damage-secondary impact" chain disaster on the same model.

[0012] The device provided by the present invention is suitable for earthquake impact sequence action test, including a support assembly, an anti-jump assembly, an axial force assembly and a drop hammer assembly; the support assembly is composed of two counterweight boxes and connecting beams, and the counterweight boxes are fixed to both sides of the test bench base with adjustable spacing through the connecting beams; the anti-jump assembly includes a limit column embedded in the counterweight box and a height-adjustable lateral constraint beam, which is used to limit the displacement of the model end; the axial force assembly is arranged at both ends of the model, including axial force blocks, tie bars and axial force application mechanisms to form a closed-loop axial force transmission system; the drop hammer assembly includes a slide rail, a drop hammer with adjustable counterweight and a hammer head, and the drop hammer is slidably connected to the slide rail; the device is suitable for the bridge pier model after the vibration table test, the special-shaped model is fixed by the support assembly, the axial force assembly applies and monitors the axial force, the anti-jump assembly suppresses impact rebound, and the drop hammer assembly simulates the impact of the collapsed body.

[0013] In one embodiment of the above device, the counterweight box is a concrete-filled steel plate box with reserved bolt holes on the side and square holes and a pouring port on the top.

[0014] In one embodiment of the above device, the connecting beam is an axial I-beam, and both ends are fastened to the bolt holes reserved in the counterweight box by bolts to achieve adjustment of the box spacing.

[0015] In one embodiment of the above device, the limit column is a vertical I-beam, which is pre-embedded and fixed to the counterweight box; the transverse restraint beam is a transverse I-beam, which is bolted to the limit column through a perforated steel plate.

[0016] In one embodiment of the above device, in the axial force assembly, the axial force applying mechanism includes a jack provided at the top of the model and a pressure sensor provided at the bottom of the model, and an anti-shattering steel plate is provided between the jack and the model.

[0017] In one embodiment of the above device, the tie bars are passed through the holes at both ends of the axial force block and are limited by bolts to form a closed loop structure.

[0018] In one embodiment of the above device, the drop hammer adjusts the impact energy through an internal counterweight block, the hammer head is made of high-strength material, and the slide rails are smooth cylinders on both sides of the test bench base.

[0019] In one embodiment of the above device, the contact surface between the model and the support component and the anti-jump component is padded with anti-shatter steel plates, wherein a V-shaped groove is opened in the middle of the anti-shatter steel plate on the top of the model and a steel roller is embedded to simulate the hinge, and a conventional steel plate is used at the bottom to simulate the fixed connection.

[0020] A method for performing a drop hammer test on a bridge pier model after a shaking table test using the above-mentioned device comprises the following specific steps:

[0021] Step 1: Assemble the support components: Select the bottom and top steel boxes based on the end dimensions of the pier model after the shaking table test. Insert vertical I-beams into the square holes on the top of the two steel boxes and secure them. Pour concrete through the pouring openings to form a counterweight anti-overturning structure. Use axial I-beams to connect the bolt holes reserved on the sides of the two steel boxes and tighten them with bolts to form the overall structure. Simultaneously adjust the spacing between the boxes to adapt to the model length.

[0022] Step 2: Simulate boundary conditions: Place anti-shatter steel plates at both ends of the model. Use a conventional steel plate at the bottom to simulate a fixed connection. Use a V-grooved steel plate with an embedded steel roller at the top to simulate a hinge. Adjust the thickness of the anti-shatter steel plate and the position of the steel roller to make the center axis of the model horizontal.

[0023] Step 3: Install the anti-jump assembly: Connect the horizontal I-beam to the inner flange of the vertical I-beam with bolts; adjust the installation position of the horizontal I-beam according to the height of the model end to limit the vertical displacement of the end during impact;

[0024] Step 4: Set up the axial force assembly: Install a pressure sensor at the bottom of the model and a jack at the top of the model; install an axial force block outside the sensor and jack, insert it into the hole through the tie rod and tighten it with bolts;

[0025] Step 5: Apply axial load: Start the jack to apply the predetermined axial force, and the pressure sensor records the load changes in real time;

[0026] Step 6: Simulate the impact of a drop hammer: Place the drop hammer sleeve on the slide rail and adjust the impact energy by adding or removing the counterweight; release the drop hammer to hit the specified position of the model to simulate the impact of rocks from the landslide after the earthquake; use the same model to continuously withstand axial force and dynamic impact to replicate the "earthquake damage-landslide impact" chain disaster coupling process.

[0027] The beneficial effects of the present invention are:

[0028] 1. By filling the concrete-filled steel plate box with adjustable spacing between axial I-beams, as well as pre-embedded vertical I-beams and liftable transverse I-beams, the system adapts to models of varying sizes. It can even handle special-shaped bridge pier models with larger lower ends and smaller upper ends after shaking table testing, overcoming the limitations of traditional drop hammer devices on model size. Furthermore, the system combines a fixed steel plate at the bottom and a V-grooved articulated steel roller at the top to simulate the fixed connection at the bottom of the model and the articulation at the top, increasing the accuracy of simulation tests.

[0029] 2. Using jacks for pressure application, pressure sensors for monitoring, and reinforcement for fastening, the system records changes in axial force under impact loads in real time. Anti-shatter steel plates effectively prevent concrete breakage at the model ends. The deadweight of the support components and anti-jump components work together to suppress impact rebound and overturning, ensuring stable boundary conditions for large-scale models under dynamic impact, significantly improving the authenticity of test data.

[0030] 3. Impact tests are conducted directly on specimens tested on the vibration table, continuously reproducing the entire process of the "earthquake damage-secondary impact" chain disaster on the same model for the first time. Rapid installation is achieved based on the existing test bench base, eliminating the need for customized modifications. This enables efficient resource reuse of the vibration table and drop hammer test platform, reducing the cost of large-scale chain disaster simulation tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the axonometric structure of an embodiment of the present invention.

[0032] Figure 2 for Figure 1 Schematic diagram of the top view structure.

[0033] Figure 3 for Figure 1 Schematic diagram of the side elevation structure.

[0034] Figure 4 for Figure 1 Installation diagram of the middle support assembly and anti-jump assembly.

[0035] Figure 5 for Figure 1 Schematic diagram of the structural explosion of the anti-jump component.

[0036] Figure 6 for Figure 1 Schematic diagram of the structure of the central axis force component.

[0037] Figure 7 It is a structural diagram of the vibration table test platform in the background technology.

[0038] Figure 8 for Figure 7 Schematic diagram of the use status of the medium vibration table test platform. DETAILED DESCRIPTION

[0039] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the relevant technical solutions. Obviously, the embodiments described are only some embodiments, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] Combine Figure 1 、 Figure 2 and Figure 3 It can be seen that the device adapted for earthquake impact sequence action test disclosed in this embodiment includes a support assembly, an anti-jump assembly, an axial force assembly and a drop hammer assembly.

[0041] like Figure 4 As shown, the support assembly includes two rectangular concrete-filled steel boxes with the same width but different lengths and heights, namely the bottom steel box 1 and the top steel box 2, which are placed on the front and back sides of the original test bench base in the test site.

[0042] Two rows of pre-set bolt holes are evenly spaced on the sides of the two steel boxes. The two boxes are connected as a whole by three axial I-beams, with the ends of the I-beams aligned with the pre-set bolt holes on the sides of the boxes and secured with bolts to enhance overturning resistance. The axial I-beams also adjust the spacing between the boxes to accommodate models of varying lengths.

[0043] Two square holes and a pouring port are provided on the top of the two steel plate boxes. The square holes are used to embed the vertical I-beam 4, and the pouring port is used to pour concrete into the steel plate boxes. After the concrete solidifies, a rigid support body is formed.

[0044] The support device of this embodiment relies on the weight of its own steel plate and internal concrete to not only effectively prevent the model from rebounding when impacted, but also avoids the end from shaking or even overturning during impact, which can fully ensure that the test process meets the expected assumptions.

[0045] like Figure 5 As shown, the anti-jump assembly includes a vertical I-beam 4 and a transverse I-beam 5.

[0046] Multiple vertical I-beams 5 are pre-buried and fixed in two steel plate boxes by pouring concrete. The upper inner flange plates of the vertical I-beams have two rows of bolt holes. The two ends of the horizontal I-beams 5 are welded with perforated steel plates, which are bolted to the vertical I-beams through the perforated steel plates.

[0047] The transverse I-beam of the anti-jump device can be adjusted in height according to the specific specimen size, and to a certain extent can adapt to models of different sizes, broadening the scope of application of the simulated post-earthquake debris flow stone impact test.

[0048] The bottom of the pier model 6 is set on the bottom steel box 1, and the top is set on the top steel box 2. Two anti-jump components pre-embedded in the corresponding steel boxes limit the two ends of the pier model to the steel boxes.

[0049] The contact positions between the supporting components, anti-jump components and the pier model are padded with anti-fragmentation steel plates 7.

[0050] A V-shaped groove is opened in the middle of the anti-fragmentation steel plates at the upper and lower ends of the top of the pier model 6, and steel rollers 8 of corresponding sizes are set in the V-shaped groove to simulate the hinged state of the top of the pier during the impact process.

[0051] The anti-shatter steel plates and the steel rollers between the plates can not only effectively prevent the test errors caused by the crushing of the concrete at the end during the impact test, thereby enhancing the authenticity of the test simulation; they can also effectively form a fixed connection at the fixed end at the bottom of the column and release the rotational freedom of the end at the top of the column to form a hinged support connection.

[0052] like Figure 6 As shown, the axial force assembly includes an axial force block 9, a tie rod 10 and a jack 11.

[0053] Axial force blocks 9 are provided at both ends of the pier model 6. The axial force blocks are square blocks made of steel. Holes are opened at both ends of the axial force blocks, and tie bars 10 are inserted into the holes and limited by bolts.

[0054] A jack 11 is provided between the top of the pier model 6 and the axial force block 9, and a pressure sensor is provided between the bottom of the pier model 6 and the axial force block. Anti-shattering steel plates are placed between the jack and the pressure sensor and the pier model.

[0055] The jack effectively simulates the axial pressure experienced by a bridge pier under real-world conditions, while a pressure sensor at the other end records the changes in axial force in real time during impact. A steel plate between the jack, sensor, and model effectively prevents axial force loads and recording distortion caused by concrete crushing.

[0056] The drop hammer assembly includes a drop hammer slide rail 12 , a drop hammer 13 and a counterweight 14 .

[0057] The drop weight slide rails 12 are smooth cylinders arranged on the left and right sides of the original test bench base in the test site.

[0058] Both ends of the drop hammer 13 are sleeved on the drop hammer slide rail 12 and can fall freely; the bottom end of the drop hammer is a hammer head made of high-strength material.

[0059] The drop hammer 13 is slotted internally and equipped with multiple counterweights 14 via a limit rod. The mass of the counterweights can be adjusted to perform drop hammer tests with varying impact forces. After the drop hammer test is completed, the drop hammer is raised via an external sling to allow for the next test.

[0060] A method for performing a drop hammer test using the device, the specific steps are as follows:

[0061] Step 1: Assemble the support components:

[0062] The bottom and top steel boxes are selected based on the end dimensions of the pier model after the shaking table test. Vertical I-beams are inserted into the square holes on the top of the two steel boxes for pre-embedding and fixation. Concrete is poured through the pouring opening to form a counterweight anti-overturning body. Axial I-beams are used to connect the bolt holes reserved on the sides of the two steel boxes, and they are fastened with bolts to form an integrated structure. The spacing between the boxes is simultaneously adjusted to suit the model length.

[0063] Step 2: Simulate boundary conditions

[0064] Anti-shatter steel plates were placed at both ends of the model, with conventional steel plates used at the bottom to simulate a fixed connection. A V-grooved steel plate with embedded steel rollers was used at the top to release rotational freedom and simulate a hinged joint. By adjusting the thickness of the anti-shatter steel plates and the position of the steel rollers, the central axis of the model was horizontal, ensuring an accurate impact load transfer path.

[0065] Step 3: Install the anti-jump component

[0066] Connect the transverse I-beam to the inner flange of the vertical I-beam with bolts; adjust the installation position of the transverse I-beam according to the height of the model end to limit the vertical displacement of the end during impact;

[0067] Step 4: Set the axial force component

[0068] A pressure sensor is installed at the bottom of the model, and a jack is installed at the top. An axial force block is installed outside the sensor and jack, inserted into the hole through a tie rod and fastened with bolts. This forms a closed-loop axial force transmission system to avoid load distortion caused by concrete crushing.

[0069] Step 5: Apply axial load

[0070] Start the jack to apply the predetermined axial force, and the pressure sensor records the load changes in real time;

[0071] Step 6: Simulate the impact of a falling hammer

[0072] The drop hammer sleeve is placed on the slide rail, and the impact energy is adjusted by adding or removing the counterweight; the drop hammer is released to hit the specified position of the model, simulating the impact of rocks from the landslide after the earthquake; the same model is used to continuously withstand axial force loads and dynamic impacts to achieve the reproduction of the "earthquake damage-secondary impact" chain disaster coupling process.

[0073] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although detailed descriptions have been provided with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A device adapted for earthquake impact sequence action testing, characterized by: It includes a support assembly, an anti-jump assembly, an axial force assembly and a drop hammer assembly; The support assembly consists of two counterweight boxes and connecting beams. The counterweight boxes are concrete-filled steel boxes with reserved bolt holes on the sides and square holes and pouring ports on the top. The counterweight boxes are fixed to both sides of the test bench base through the connecting beams with adjustable spacing. The connecting beams are axial I-beams, with both ends fastened to the reserved bolt holes of the counterweight boxes by bolts. The anti-jump assembly includes a limit column embedded in the counterweight box and a height-adjustable transverse restraint beam. The limit column is a vertical I-beam embedded and fixed in the counterweight box; the transverse restraint beam is a transverse I-beam, connected to the limit column bolts through a perforated steel plate, used to limit the displacement of the model end; The axial force assembly is installed at both ends of the model, including axial force blocks, tension bars and axial force application mechanisms, forming a closed-loop axial force transmission system; the drop hammer assembly includes a slide rail, a drop hammer with adjustable counterweight and a hammer head, and the drop hammer is slidably connected to the slide rail; Anti-shatter steel plates are placed on the contact surfaces between the model and the support and anti-jump components. A V-shaped groove is opened in the middle of the anti-shatter steel plate on the top of the model and a steel roller is embedded to simulate a hinge. Conventional steel plates are used on the bottom to simulate a fixed connection. The device is adapted to the bridge pier model after the shaking table test. The special-shaped model is fixed by the support component, the axial force component applies and monitors the axial force, the anti-jump component suppresses the impact rebound, and the drop hammer component simulates the impact of the landslide body, continuously reproducing the entire "earthquake damage-secondary impact" chain disaster process on the same model.

2. The device for adapting to the earthquake impact sequence action test according to claim 1, characterized in that: In the axial force assembly, the axial force applying mechanism includes a jack arranged on the top of the model and a pressure sensor arranged on the bottom of the model, and an anti-shattering steel plate is arranged between the two and the model.

3. The device for adapting to the earthquake impact sequence test according to claim 2, characterized in that: The tie bars are passed through the holes at both ends of the axial force block and are limited by bolts to form a closed loop structure.

4. The device for adapting to the earthquake impact sequence test according to claim 1, characterized in that: The drop hammer adjusts the impact energy through the internal counterweight block. The hammer head is made of high-strength material, and the slide rails are smooth cylinders on both sides of the test bench base.

5. A method for performing a drop hammer test on a bridge pier model after a shaking table test using the apparatus according to any one of claims 1 to 4, comprising the following steps: Step 1: Assemble the support components: Select the bottom and top steel boxes based on the end dimensions of the pier model after the shaking table test. Insert vertical I-beams into the square holes on the top of the two steel boxes and secure them. Pour concrete through the pouring openings to form a counterweight anti-overturning structure. Use axial I-beams to connect the bolt holes reserved on the sides of the two steel boxes and tighten them with bolts to form the overall structure. Simultaneously adjust the spacing between the boxes to adapt to the model length. Step 2: Simulate boundary conditions: Place anti-shatter steel plates at both ends of the model. Use a conventional steel plate at the bottom to simulate a fixed connection. Use a V-grooved steel plate with an embedded steel roller at the top to simulate a hinge. Adjust the thickness of the anti-shatter steel plate and the position of the steel roller to make the center axis of the model horizontal. Step 3: Install the anti-jump assembly: Connect the horizontal I-beam to the inner flange of the vertical I-beam with bolts; adjust the installation position of the horizontal I-beam according to the height of the model end to limit the vertical displacement of the end during impact; Step 4: Set up the axial force assembly: Install a pressure sensor at the bottom of the model and a jack at the top of the model; install an axial force block outside the sensor and jack, insert it into the hole through the tie rod and tighten it with bolts; Step 5: Apply axial load: Start the jack to apply the predetermined axial force, and the pressure sensor records the load changes in real time; Step 6: Simulate the impact of a drop hammer: Place the drop hammer sleeve on the slide rail and adjust the impact energy by adding or removing the counterweight; release the drop hammer to hit the specified position of the model to simulate the impact of rocks from the landslide after the earthquake; use the same model to continuously withstand axial force and dynamic impact to replicate the "earthquake damage-secondary impact" chain disaster coupling process.

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