Three-way layered shearing assembly type model box for simulating underground structure under earthquake action

Abstract

The invention relates to the field of rock and soil earthquake engineering, and particularly discloses a three-way layered shearing assembly type model box for simulating an underground structure under earthquake action, which comprises eleven layers of H-shaped aluminum alloy rectangular frame laminated structures, eight groups of integrated EG series four-row steel ball linear guide rails, high-strength self-resetting springs and MEMS displacement sensor three-way shearing connecting devices, the model box adopts a bolt assembly type design, and is provided with a 3m * 3m Q345B steel plate bottom plate and a cross H-shaped steel external limiting frame. The device can synchronously simulate X / Y / Z three-direction six-degree-of-freedom seismic actions, realizes submillimeter displacement control through white noise frequency sweeping calibration, effectively inhibits boundary reflected wave interference, is suitable for seismic performance research of structures such as underground pipe galleries and subway stations, and has the advantages of rapid disassembly and assembly and accurate reproduction of three-dimensional coupling vibration.

Description

Technical Field

[0001] The invention relates to the technical field of geotechnical earthquake engineering, in particular to a three-dimensional layered shear assembly model box simulating an underground structure under the action of earthquake motion. Background Art

[0002] In recent years, with the continued expansion of urban underground space development, the seismic safety of large underground structures such as subway stations and utility corridors under complex three-dimensional seismic motions has become increasingly prominent. In seismic research on underground structures, using shaking table model tests to study the seismic response characteristics of underground structures and verify the rationality of existing results has become an effective means of studying the seismic performance of underground structures. To more accurately simulate the dynamic response of underground structures under three-dimensional (six degrees of freedom in the X / Y / Z directions) seismic motion, it is particularly important to rationally design a continuum model box for multi-array shaking table testing.

[0003] Traditional shaking table model boxes mostly adopt a unidirectional or bidirectional layered shear design, and their lateral constraints are fixed with rigid steel plates and bolts. When simulating the three-dimensional shear deformation of the soil, the boundary reflection wave energy accounts for more than 30%, which seriously interferes with the measurement accuracy of the soil-structure interaction force and makes it difficult to meet the requirements of the seismic design code for the refined analysis of underground structures.

[0004] Existing model boxes face significant technical bottlenecks in multidimensional seismic motion simulation. First, traditional prefabricated frames rely on one-way slide rails, enabling only horizontal shear displacements. Z-axis stiffness redundancy is insufficient, making it impossible to simultaneously simulate the coupling effects of vertical seismic components and horizontal shear. Second, the integrally welded structure results in inefficient assembly and disassembly, and the consistency of test results after repeated assembly is significantly reduced. Furthermore, existing support systems generally utilize fixed supports or low-precision sliding devices, which can easily cause the structure to lift or overturn when simulating Z-axis vibrations.

[0005] Based on this, this study proposed a three-dimensional layered shear assembly model box to simulate underground structures under earthquake motion. Summary of the Invention

[0006] In response to the above-mentioned problems of the prior art, the present invention provides a three-dimensional layered shear assembly model box that simulates the underground structure under the action of seismic motion, which can accurately simulate the seismic response of the underground structure under the action of three-dimensional seismic motion and effectively improve the test efficiency.

[0007] To achieve the above-mentioned objectives, the present invention proposes a three-way layered shear assembly model box that simulates underground structures under the action of seismic vibrations, comprising: a plurality of stacked rectangular frames, a three-way shear connection device arranged between adjacent rectangular frames, a steel plate bottom plate supporting the rectangular frames, and a cross-shaped H-shaped steel external limit frame surrounding the rectangular frames.

[0008] Preferably, the rectangular frame is an eleven-layer stacked structure, and a single-layer frame is constructed by bolting an H-shaped aluminum alloy of 2200mm×2000mm, with a spacing of 10mm between adjacent frames.

[0009] Preferably, the three-way shear connection device is provided with EG series low-assembly linear guide rails in two horizontal directions and a sleeve in the vertical direction, and a high-strength self-resetting spring and a MEMS displacement sensor are installed in the sleeve.

[0010] Preferably, the MEMS displacement sensor has a measuring range of ±150 mm and a sampling rate of 1 kHz.

[0011] Preferably, the bottom plate is made of 16mm thick steel plate, with a length×width of 3m×3m, and has holes with a diameter of 32mm on all sides. It is connected to the vibration table by bolts, and the bottom plate is connected to the bottom of the rectangular frame by bolts.

[0012] Preferably, the external limiting frame is a cross-shaped frame made of an H-shaped steel frame that limits the overall displacement of the model box.

[0013] Preferably, the middle layer of the rectangular frame is connected to the three-way shear connection device by bolt connection, and 8 three-way shear connection devices are evenly arranged between two adjacent layers of the rectangular frame.

[0014] Preferably, the model box further comprises a correction system, which obtains the fundamental frequency of the model box by white noise frequency sweeping, and corrects the preload force of the shear devices between each layer by means of a built-in MEMS displacement sensor.

[0015] Preferably, the model box is an assembled structure, and the components are connected by bolts and connecting devices.

[0016] Preferably, the assembly process of the model box includes:

[0017] Step 1: Connect the bottom rectangular frame 1 to the bottom plate 3 and fix them to the vibration table with M30 high-strength bolts;

[0018] Step 2: hoist the middle layer rectangular frame 1 layer by layer, and complete the inter-layer connection through the three-way shear connection device 2;

[0019] Step 3: Install the external limit frame 4 to complete the assembly of the entire model box;

[0020] Step 4: Sweep the white noise frequency to obtain the fundamental frequency of the model box, and calibrate the preload of the shear device between each layer through the built-in MEMS displacement sensor.

[0021] Therefore, the present invention proposes a three-dimensional layered shear assembly model box that simulates underground structures under earthquake motion, and its beneficial effects are as follows:

[0022] Through its three-dimensional layered shear design, the model box can accurately simulate the seismic response of underground structures under three-dimensional ground motion, effectively reducing the influence of the model box boundary effects, thereby more accurately simulating the horizontal shear behavior of the soil. In addition, the model box adopts an assembled design, which facilitates rapid assembly and disassembly on site, greatly improving testing efficiency. At the same time, the built-in new three-dimensional shear connection device and high-precision MEMS displacement sensor not only enhance the stability of the structure, but also enable real-time monitoring of the ground motion process, providing a more reliable and efficient solution for geotechnical engineering shaking table testing.

[0023] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is an oblique view of an assembled three-dimensional layered shear assembly model box for simulating an underground structure under earthquake motion according to the present invention;

[0025] Figure 2 This is a front view of an assembled three-dimensional layered shear assembly model box for simulating underground structures under earthquake motion according to the present invention;

[0026] Figure 3 This is an oblique view of an end box of a three-dimensional layered shear assembly model box for simulating an underground structure under earthquake motion according to the present invention;

[0027] Figure 4 This is an oblique view of a three-way shear connection device of a three-way layered shear assembly model box simulating an underground structure under earthquake motion according to the present invention;

[0028] Reference numerals

[0029] 1. Rectangular frame; 2. Three-way shear connection device; 3. Base plate; 4. External frame; 5. First linear guide rail; 6. Second linear guide rail; 7. Sleeve; 8. Self-resetting spring. DETAILED DESCRIPTION

[0030] To make the technical solutions, advantages, and purposes of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The described embodiments are part of the embodiments of the present invention, not all of them. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0031] Unless otherwise defined, technical or scientific terms used in the present invention shall have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

[0032] like Figures 1-4 As shown, according to the present invention, a three-way layered shear assembly model box is provided to simulate the underground structure under the action of earthquake vibration. The device is installed on a vibration table and includes a rectangular frame 1, a three-way shear connection device 2, a base plate 3, and an external frame 4.

[0033] The model consists of eleven layers of rectangular frames stacked one on top of the other. Each layer is connected by two 2200mm and two 2000mm H-shaped aluminum alloy bolts to simulate the horizontal shear properties of soil. The rectangular frames are spaced 10mm apart and connected in between using a three-way layered shear device.

[0034] The rectangular frame of the middle layer is connected to the three-way shear connection device 2 by bolt connection, and eight three-way layered shear devices 2 are arranged between two adjacent layers of rectangular frames 1 to work together.

[0035] The three-way shear connection device 2 consists of two horizontal EG series low-assembly type first linear guide rails 5 and second linear guide rails 6 and a vertical sleeve 7. A high-strength self-resetting spring 8 is installed inside the vertical sleeve. The first linear guide rails 5 and the second linear guide rails 6 control the two horizontal degrees of freedom, and the sleeve 7 controls the vertical degree of freedom, thereby realizing the three-way free vibration of the model device.

[0036] The EG series low-assembly linear guide uses a four-row steel ball load-bearing design, giving it high rigidity and high load characteristics. It also has four-directional load characteristics and an automatic centering function to absorb assembly errors on the mounting surface.

[0037] The maximum travel of the three-way shear connection device 2 in the X, Y, and Z directions is 18 mm. A built-in MEMS displacement sensor with a ±150 mm range and a 1 kHz sampling rate is used to monitor and record the displacement of the shear device between layers in real time, ensuring that the displacement control accuracy is within an error range of no more than 2%.

[0038] The base plate 3 is made of 16mm thick Q345B steel plate, with a length x width of 3m x 3m. It has holes on all sides, with bolt holes arranged in a 400mm x 400mm array, and a hole diameter of 32mm ± 0.1mm. It is connected to the vibration table via bolts when in use.

[0039] The external frame 4 is a cross-shaped frame made of an H-shaped steel frame, which serves as a limit for the overall position of the model box and ensures the safety of the test.

[0040] This device is a prefabricated assembled model box. The various components are connected by bolts and connecting devices and can be assembled and used on site.

[0041] The model box also includes a correction system that obtains the fundamental frequency of the model box through white noise frequency sweeping, and corrects the preload of the shear device between each layer through the built-in MEMS displacement sensor.

[0042] The assembly process of the model box includes:

[0043] Step 1: Connect the bottom rectangular frame 1 to the bottom plate 3 and fix them to the vibration table with M30 high-strength bolts;

[0044] Step 2: hoist the middle layer rectangular frame 1 layer by layer, and complete the inter-layer connection through the three-way shear connection device 2;

[0045] Step 3: Install the external limit frame 4 to complete the assembly of the entire model box;

[0046] Step 4: Sweep the white noise frequency to obtain the fundamental frequency of the model box, and calibrate the preload of the shear device between each layer through the built-in MEMS displacement sensor.

[0047] Therefore, the present invention provides a three-dimensional layered shear assembly model box that simulates the three-dimensional layered shear motion of underground structures under earthquake motion. The model box simulates the three-dimensional layered shear motion of underground structures under earthquake motion through a three-dimensional shear connection device. The EG series low-assembly linear guide rails and high-strength self-resetting springs in the three-dimensional shear connection device allow the model box to shear horizontally and vertically, while the MEMS displacement sensor monitors and controls the displacement accuracy in real time. The model box ensures the accuracy of the preload force of the shear devices between each layer through a correction system, thereby more accurately simulating the response of the underground structure under earthquake motion.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A three-dimensional layered shear assembly model box for simulating underground structures under earthquake motion, characterized in that: include: A plurality of stacked rectangular frames, a three-way shear connection device arranged between adjacent rectangular frames, a steel plate bottom plate supporting the rectangular frames, and a cross-shaped H-shaped steel external limiting frame surrounding the rectangular frames.

2. A three-dimensional layered shear assembly model box for simulating underground structures under earthquake motion according to claim 1, characterized in that: The rectangular frame is an eleven-layer stacked structure, and a single-layer frame is constructed by bolting H-shaped aluminum alloy of 2200mm×2000mm, with a spacing of 10mm between adjacent frames.

3. The three-dimensional layered shear assembly model box for simulating underground structures under earthquake motion according to claim 1, characterized in that: The three-way shear connection device is provided with EG series low-assembly linear guide rails in two horizontal directions and a sleeve in the vertical direction. A high-strength self-resetting spring and a MEMS displacement sensor are installed in the sleeve.

4. The model box according to claim 3, characterized in that The MEMS displacement sensor has a measuring range of ±150 mm and a sampling rate of 1 kHz.

5. The three-dimensional layered shear assembly model box for simulating underground structures under earthquake motion according to claim 1, characterized in that: The bottom plate is made of 16mm thick steel plate, with a length×width of 3m×3m, and has holes with a diameter of 32mm on all sides. It is connected to the vibration table by bolts, and the bottom plate is bolted to the bottom of the rectangular frame.

6. The three-dimensional layered shear assembly model box for simulating underground structures under earthquake motion according to claim 1, characterized in that: The external limiting frame is a cross-shaped frame made of an H-shaped steel frame that limits the overall displacement of the model box.

7. The three-dimensional layered shear assembly model box for simulating underground structures under earthquake motion according to claim 1, characterized in that: The middle layer of the rectangular frame is connected to the three-way shear connection device by means of bolt connection, and eight three-way shear connection devices are evenly arranged between two adjacent layers of the rectangular frame.

8. The three-dimensional layered shear assembly model box for simulating underground structures under earthquake motion according to claim 1, characterized in that: The model box also includes a correction system, which obtains the fundamental frequency of the model box through white noise frequency sweep and corrects the preload force of the shear device between each layer through the built-in MEMS displacement sensor.

9. The three-dimensional layered shear assembly model box for simulating underground structures under earthquake motion according to claim 1, characterized in that: The model box is an assembled structure, and the components are connected by bolts and connecting devices.

10. The three-dimensional layered shear assembly model box for simulating underground structures under earthquake motion according to claim 1, characterized in that: The assembly process of the model box includes: Step 1: Connect the bottom rectangular frame 1 to the bottom plate 3 and fix them to the vibration table with M30 high-strength bolts; Step 2: hoist the middle layer rectangular frame 1 layer by layer, and complete the inter-layer connection through the three-way shear connection device 2; Step 3: Install the external limit frame 4 to complete the assembly of the entire model box; Step 4: Sweep the white noise frequency to obtain the fundamental frequency of the model box, and calibrate the preload of the shear device between each layer through the built-in MEMS displacement sensor.

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