Earth vibration mountain terrain effect simulation test device

Abstract

The invention relates to the field of earthquake engineering tests, and particularly discloses a ground vibration mountain terrain effect simulation test device, which is characterized by comprising an excitation device used for generating a dynamic load to simulate earthquake vibration input, and the excitation device comprises a groove track and a small ball capable of rolling on the groove track, the small ball falls from different heights to impact gaskets made of different materials at the bottom of the physical test model or below the model, so that excitation of P-wave and S-wave pulse dynamic loads is realized; the physical test model is used for simulating the actual mountain terrain, the physical test model meets the similarity ratio requirement by adjusting the material ratio and geometric parameters of the model based on the elevation data of the actual mountain and the physical and mechanical parameters of the rock-soil body, and a mechanical parameter-material component database is established through a material ratio orthogonal test; it is ensured that the model wave velocity, elastic modulus and other key indexes and prototype errors are smaller than or equal to 5%, the physical similarity requirement in the similarity theory is met, and data support is provided for terrain effect quantitative analysis.

Description

Technical Field

[0001] The present invention relates to the earthquake engineering test industry, in particular to a simulation test device for earthquake motion mountain terrain effect. Background Art

[0002] In earthquake engineering research, accurate analysis of the effects of ground motion on mountain terrain is crucial for assessing disaster risks, guiding engineering design, and formulating earthquake mitigation strategies. Key technologies currently used include macroscopic surveys of earthquake damage, strong motion observations, analytical analysis, numerical simulation, and shaking table tests. Macroscopic surveys of earthquake damage and strong motion observations are intuitive tools that capture new phenomena of terrain effects through real-world data. Analytical analysis relies on simplified models and mathematical methods to provide qualitative theoretical guidance for observational records. Numerical simulation, due to its high applicability, has become mainstream, simulating actual conditions through modeling and revising computational models. Shaking table tests precisely input ground motions to simulate terrain effects in a real-world earthquake environment.

[0003] However, existing technologies have significant drawbacks: strong motion observations require significant human and material resources, and uncertainties in observation object selection, instrument performance, array deployment, and data processing directly impact the results, making implementation difficult. Analytical methods are limited by mathematical tools, resulting in oversimplified models that fail to account for irregular terrain, material properties, and geological structures. They can only provide qualitative analysis and require high computational power. The core challenge of numerical simulation is modeling rationality. Despite advances in computing technology, the accurate selection of constitutive relationships and material parameters for mountain geological bodies remains difficult, limiting simulation accuracy. Shaking table tests are limited by similarity ratios, making physical model preparation complex, time-consuming, and costly, making them difficult to meet the needs of in-depth research on complex terrain. To address these technical bottlenecks, there is an urgent need to develop an efficient, accurate, and economical simulation test device to overcome the practical limitations of existing methods and promote the engineering application of earthquake motion mountain terrain effects research. Summary of the Invention

[0004] The purpose of the present invention is to provide a test device for simulating the effects of earthquake motion on mountain terrain, so as to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] Physical test model:

[0007] Geometric design: Based on actual mountain elevation data (e.g., Zigong West Mountain, 472m long, 265m wide, and 140m high), the model dimensions were 112.38cm × 63.09cm × 33.33cm, using a 1:420 geometric similarity ratio. Three-dimensional terrain modeling was performed using Rhino software, combined with 3D printing technology (FDM process, 0.2mm layer thickness) to create the model, accurately recreating the original topographic relief (elevation error ≤ 0.5mm) and the distribution of strata and lithology (e.g., interbedded mudstone and sandstone).

[0008] Material Proportion: Portland cement, 40-70 mesh / 16-26 mesh mixed sand, and water were used as the base materials, with 5% silica fume (to enhance early strength), 2% early strength agent (to shorten the curing cycle), and 3% latex powder (to improve toughness) added. The mass ratio was Portland cement: mixed sand: water = 1:2:0.4 (40-70 mesh: 16-26 mesh in the mixed sand = 1:1). Uniaxial compression tests and ultrasonic wave velocity measurements ensured that the model's mechanical parameters were consistent with the prototype's third sequence: elastic modulus 7.438 GPa, Poisson's ratio 0.355, longitudinal wave velocity 1963 m / s, and shear wave velocity 1192 m / s. The error was ≤3% compared to the prototype survey values (longitudinal wave 2000±37 m / s, shear wave 1200±8 m / s, Poisson's ratio 0.35±0.02).

[0009] Excitation device:

[0010] Structural composition: includes adjustable height groove track (stainless steel material, track inclination 15°, height adjustment range 0.5-2m) and impact ball (mass 3kg, smooth surface steel ball).

[0011] Load simulation principle:

[0012] P-wave excitation: The ball falls freely from the top of the track and directly hits the rigid base at the bottom of the model. The impact force generates a longitudinal wave (compression wave) pulse dynamic load. The impact energy is determined by the mass of the ball (m) and the falling height (h);

[0013] S-wave excitation: An elastic gasket (e.g., a 40 Shore A rubber or resin gasket, 5 mm thick) is placed at the bottom of the model. When the ball strikes the gasket, shear force is generated, stimulating a shear wave (shear wave) pulse dynamic load. By changing the gasket material (adjusting stiffness) and the impact position (0-20 cm from the model center), different waveforms and propagation paths can be simulated.

[0014] Data acquisition system:

[0015] Sensor deployment: Accelerometers (range ±5g, accuracy 0.1% FS) and strain gauges (grid length 2mm, sensitivity coefficient 2.08±1%) were attached at key locations of the model (top, foot of slope, stratum interface, and bottom of the model), totaling 12 monitoring points.

[0016] Data acquisition: A dynamic signal acquisition instrument (sampling frequency 10kHz) is used to synchronously record the acceleration time history curve (resolution 0.001g) and strain data at the moment of impact. Spectral analysis and time history comparison are performed using supporting software (such as LabVIEW) to obtain key parameters such as the seismic amplification factor and waveform conversion law.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] Efficient model preparation: Through the 1:420 ultra-scale design, the model volume is only 1 / 7408800 of the traditional vibration table model (calculated by the cube of the linear similarity ratio), the 3D printing cycle is shortened to 72 hours, and the material cost is reduced by more than 90%;

[0019] Accurate load simulation: the drop height of the ball is linearly related to the energy (R 2 =0.998), can simulate pulse loads in the range of 0.1-10J, covering energy levels from small earthquakes (magnitude 3) to moderate earthquakes (magnitude 6), and the P-wave / S-wave excitation mode switching time is less than 5 minutes;

[0020] Parameter matching standardization: Through orthogonal material ratio tests, a mechanical parameter-material component database is established to ensure that the error between the model wave velocity, elastic modulus and other key indicators and the prototype is ≤5%, meeting the physical similarity requirements in similarity theory;

[0021] Comprehensive data collection: The multi-dimensional sensor network enables full-domain dynamic response monitoring of the model. Combined with the high-speed acquisition system, it can capture transient vibration signals at the 0.1ms level, providing data support for quantitative analysis of terrain effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The figure is a schematic structural diagram of an excitation device in a test device for simulating earthquake-induced mountain terrain effects according to an embodiment of the present invention.

[0023] Figure 2 The figure is a structural schematic diagram of a physical experimental model in a test device for simulating earthquake-induced mountain terrain effects according to an embodiment of the present invention.

[0024] Figure 3 This is a graph showing the acceleration of a falling ball at station 1#, which is located at a height of 5 cm, in a physical experimental model in a test device for simulating the effects of earthquakes on mountain terrain according to an embodiment of the present invention.

[0025] Figure 4 This is a recording diagram of the acceleration of a small ball 1# falling from a height of 40 cm in a physical experimental model in a test device for simulating the effects of earthquakes on mountain terrain in an embodiment of the present invention.

[0026] Figure 5 This is a cross-correlation analysis diagram of 5 cm height drop 1# and other sites of the physical experimental model in a seismic mountain terrain effect simulation test device in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the 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.

[0028] Taking the terrain simulation of Zigong Xishan as an example, the specific implementation steps are as follows:

[0029] (1) Prototype data collection:

[0030] Terrain data: Prototype elevation data (resolution 0.1 m) was obtained through UAV oblique photography, and boundary dimensions were extracted (length 472 m, width 265 m, and maximum altitude 140 m).

[0031] Geotechnical parameters: Drilling sampling was used to determine the prototype third sequence (mudstone and sandstone interbeds). Mechanical parameters: P-wave velocity 2000 m / s, S-wave velocity 1200 m / s, Poisson's ratio 0.35, density 2200 kg / m 3 .

[0032] (2) Model preparation:

[0033] Geometric Scale: Model dimensions were calculated using a 1:420 similarity ratio. A 3D terrain model (including 1:1000 precision contour lines) was created using Rhino software. The STL file was exported and then printed layer by layer using an FDM 3D printer (nozzle diameter 0.4mm). The material used was a custom cement-based mixture.

[0034] Material preparation: Weigh 500g of silicate cement, 1000g of mixed sand (500g each of 40-70 mesh and 16-26 mesh), and 200g of water according to the mass ratio, add 25g of silica fume, 10g of early strength agent, and 15g of latex powder, stir evenly, pour into the mold, vibrate to compact, and cure for 28 days to make a standard cylindrical specimen (φ50mm×100mm) for mechanical properties testing.

[0035] Table 1 Material parameters used in model making

[0036]

[0037] (3) Debugging of the excitation device:

[0038] P-wave simulation: A 3kg steel ball was placed on a 1m high track and allowed to freely fall onto the center of the bottom of the model. The impact force was calibrated using a force sensor (accuracy 0.1N) (measured 3.2N, corresponding to an energy of 1.96J).

[0039] S-wave simulation: A 5mm-thick rubber gasket (elastic modulus 10 MPa) was replaced. The same steel ball was dropped from a height of 1.5m and impacted the edge of the gasket (10cm from the center of the model). The shear wave propagation direction (parallel to the model surface) was verified using a laser vibrometer.

[0040] (4) Data collection and analysis:

[0041] Sensor layout: Monitoring elements were attached to the top of the model mountain (3 accelerometers), the foot of the slope (2 strain gauges), the stratum interface (5 accelerometers), and the bottom base (2 reference sensors). Wires were connected to the data collector through the holes reserved in the model.

[0042] Signal processing: Band-pass filtering (0.1-500Hz) is performed on the original acceleration signal, and the acceleration amplification coefficient between each measuring point and the bottom base is calculated (for example, the amplification coefficient of the mountain top measuring point is 1.82, which is consistent with the prototype earthquake damage survey results). Combined with the strain data, the stress distribution cloud map of the key section is drawn.

[0043] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A test device for simulating the effects of earthquake motion on mountain terrain, characterized in that: include: An excitation device for generating a dynamic load to simulate earthquake input, the excitation device comprising a grooved track and a ball that can roll on the grooved track. The ball is dropped from different heights to impact the bottom of the physical test model or gaskets made of different materials below the model, thereby achieving the excitation of P-wave and S-wave pulse dynamic loads; The physical test model is used to simulate the actual mountain terrain. The physical test model is based on the elevation data of the actual mountain and the physical and mechanical parameters of the rock and soil. The similarity ratio requirements are met by adjusting the model material ratio and geometric parameters.

2. The earthquake-induced mountain terrain effect simulation test device according to claim 1 is characterized in that: The materials of the physical test model include silicate cement, sand, water, and one or more of silica fume, early strength agent, and latex powder; the mass ratio of the silicate cement: sand: water is 1:2:0.4, wherein the silica fume content is 5%, the early strength agent content is 2%, and the latex powder content is 3%.

3. The earthquake-induced mountain terrain effect simulation test device according to claim 2, characterized in that: The geometric similarity ratio is 1:420, and the size of the physical test model is reduced by a ratio of 1:420 according to the actual mountain size; the mass and falling height of the ball are determined by similarity ratio calculation to match earthquake load inputs of different intensities.

4. The earthquake-induced mountain terrain effect simulation test device according to claim 3 is characterized in that: The adjustment range of the groove track height of the excitation device is 0.5-2m, and the mass of the ball is 3kg; when the ball falls freely from the top of the track, it excites P waves by directly hitting the bottom of the model, or excites S waves by hitting the elastic gasket under the model.

5. The earthquake-induced mountain terrain effect simulation test device according to claim 4 is characterized in that: The physical test model is constructed by using a terrain data model using 3D modeling software and is produced at a scale of 1:420 using 3D printing technology.

6. The earthquake-induced mountain terrain effect simulation test device according to claim 5, characterized in that: The material mechanical parameters of the physical test model match those of the prototype, specifically: the elastic modulus of the model is 7.438 GPa, the Poisson's ratio is 0.355, the P-wave velocity is 1963 m / s, and the S-wave velocity is 1192 m / s.

7. The earthquake-induced mountain terrain effect simulation test device according to claim 6 is characterized in that: The data acquisition system includes acceleration sensors arranged at the top of the model mountain, the foot of the slope, and the interface of the strata, and is used to synchronously acquire the seismic input signal and the model dynamic response signal.

Images