A seismic isolation and damping system based on tree spatial layout form

Abstract

The application belongs to the technical field of earthquake prevention and disaster reduction, and proposes a seismic isolation and damping system based on spatial arrangement of trees. The system comprises a density gradient tree arrangement area, a periodic tree array area, a target protection area and a buffer transition zone. The density gradient arrangement area is located at the front end of the system, and the tree density gradually increases along the direction of seismic wave propagation, which is used to realize impedance smooth transition and guide wave energy into the array area; the trees in the periodic array area are arranged at equal intervals to form a quasi-periodic elastic structure, which is used to produce Bragg scattering band gap effect, reflect and dissipate seismic waves of a specific frequency band; the target protection area is used to arrange buildings or infrastructure that need to be protected; the buffer transition zone is arranged between the array end and the target area, which is used to absorb residual wave energy and reduce echo amplification effect. The application constructs a green, low-cost and sustainable natural seismic isolation system, which has good seismic wave control effect and engineering adaptability.

Description

Technical Field

[0001] This application belongs to the field of earthquake prevention and disaster reduction technology, specifically relating to an earthquake isolation and damping system based on the spatial arrangement of trees. Background Technology

[0002] Current seismic isolation and damping devices commonly used in engineering construction and building complexes, such as lead-core bearings, viscous dampers, and viscoelastic damping walls, can improve the seismic performance of structures to a certain extent, but they generally suffer from high manufacturing costs, complex maintenance, limited service life, and poor environmental adaptability. Especially in rural areas, mountainous regions, and ecologically sensitive areas, traditional devices are difficult to promote on a large scale due to cost and applicability issues. Therefore, there is an urgent need for a new type of green, low-cost, and sustainable seismic isolation and damping technology.

[0003] Recent studies have found that natural media such as trees, during seismic wave propagation, can form a mechanically coupled structure with the foundation through the bending elasticity of their trunks and the anchoring effect of their root systems. Under the action of seismic shear waves, this mechanically coupled structure can produce scattering, local reflection, and energy dissipation effects on the incident waves, exhibiting wave regulation capabilities similar to artificial energy-dissipating structures, thus providing a certain degree of "flexible damping" for the natural environment. Existing experiments and numerical simulations have shown that densely vegetated areas can significantly disturb the propagation paths of shear waves and surface waves, possessing potential seismic isolation and damping functions. However, related research mostly remains at the level of phenomenological observation, lacking systematic design methods and engineering-implementable structural configurations or spatial layout strategies, which limits the practical application of natural vegetation in the field of earthquake prevention and disaster reduction.

[0004] Meanwhile, "artificial periodic structures" based on the theory of seismic metamaterials have shown significant advantages in the field of wave control in recent years. Seismic metamaterials are a class of artificial periodic structural systems that control the propagation behavior of elastic waves by precisely designing periodic structural parameters. Typical artificial periodic structures induce Bragg scattering of seismic waves within a specific frequency band by constructing periodic changes in stiffness, density, or interfacial impedance, thereby forming a "seismic bandgap" that effectively suppresses the propagation of seismic waves in that frequency band, possessing frequency-selective shielding and wave localization capabilities. Although these "artificial periodic structures" have shown good vibration reduction performance in laboratories and localized engineering projects, their complex construction, long manufacturing cycle, and the need for high-precision control during installation and deployment hinder their widespread application.

[0005] Against this backdrop, naturally occurring structures with periodic characteristics, such as forests (quasi-periodic elastic structures), are considered a low-cost, environmentally friendly medium for modulating seismic waves. The trunks and roots of forests spatially constitute a natural, quasi-elastic periodic structure with wave scattering capabilities, theoretically capable of achieving an "earthquake bandgap" effect similar to artificial metamaterials. Therefore, it is urgent to understand their natural modulating mechanisms and, combined with scientific layout design and density gradient control, construct an ecological seismic isolation and damping system based on the spatial arrangement of trees, possessing both natural characteristics and engineering functions. This would provide a new path for achieving cost-effective and sustainable seismic protection for engineering buildings and building complexes. Summary of the Invention

[0006] To address the aforementioned issues, this application proposes a seismic isolation and damping system based on the spatial arrangement of trees. By scientifically arranging trees in space, they form a natural elastic structure with band gap effect and energy dissipation capability in the seismic wave propagation path, thereby achieving a green, low-cost, and sustainable seismic isolation and damping effect.

[0007] To achieve the above objectives, this application adopts the following technical solution:

[0008] A seismic isolation and damping system based on the spatial arrangement of trees includes a density-gradient tree arrangement zone 2, a periodic shape tree array zone 3, a buffer transition zone 4, and a target protection zone 5, wherein:

[0009] The density-gradient tree deployment area 2 is located at the front end of the seismic isolation and damping system, facing the direction of potential seismic wave incidence. The tree density gradually increases along the direction of seismic wave propagation. It is used to construct a flexible transition zone with gradually changing wave impedance characteristics, realize a smooth impedance transition, thereby reducing the reflection intensity of the incident wave and guiding the wave energy into the rear periodic shape tree array area 3.

[0010] The periodic shape tree array area 3 is set after the density gradient tree layout area 2. The trees are arranged at equal intervals to form a two-dimensional elastic periodic structure, which triggers the Bragg scattering effect in a specific frequency band, effectively reflecting and dissipating incident seismic waves, and realizing the wave propagation suppression function in the target frequency band.

[0011] The buffer transition zone 4 is set between the periodic shape tree array area 3 and the target protection area 5 to further absorb the seismic wave energy that is not completely dissipated by the periodic structure and reduce the reflection and interference superposition effect of seismic waves in this area.

[0012] The target protection zone 5 is located after the periodic character-shaped tree array zone 3. As the core protected area in the seismic isolation and damping system, it is used to deploy the engineering buildings and building complexes to be protected.

[0013] Furthermore, the specific arrangement of the density-gradient tree distribution area is as follows:

[0014] A density-gradient tree planting area is set up on the side closest to the direction of seismic wave incidence;

[0015] The spacing between trees was gradually reduced along the direction of seismic wave propagation.

[0016] Tree species with shallow root systems and good flexibility are preferred for the layout to enhance the adaptability and deformation capacity of the structure, forming a flexible, gradually changing medium layer that can buffer fluctuations and guide energy propagation.

[0017] Furthermore, the specific layout of the periodic shape tree array area is as follows:

[0018] After the area with trees of gradually varying density, a grid-like array of trees with equal spacing is laid out, which serves as the main wave scattering and reflection functional structure in the seismic isolation and damping system.

[0019] The array spacing d is designed based on the target bandgap frequency and should satisfy the Bragg scattering condition, as shown in formula (1):

[0020] 2dsinθ=nλ (1)

[0021] In the formula, λ is the wavelength of the seismic wave, θ is the incident angle, and n is an integer;

[0022] The selected tree species are preferably those with well-developed root systems and high trunk rigidity to enhance their ability to resist and reflect seismic waves.

[0023] The layout can be square, hexagonal, or staggered to accommodate multi-directional wave propagation and extend the bandwidth.

[0024] Furthermore, under the action of seismic motion, the front density gradient tree layout area and the periodic shape tree array area form a synergistic impedance system, which together weakens the kinetic energy density of seismic waves during propagation, reduces the intensity of seismic motion entering the target protection area 5, and thus improves the seismic safety of structures within the target protection area.

[0025] Furthermore, the buffer transition zone is specifically arranged as follows:

[0026] A buffer zone of a certain width is reserved between the end of the periodic tree array area and the target protection area as an energy attenuation zone to absorb residual fluctuation energy.

[0027] Additional damping devices can be designed in conjunction with shallow underground root systems or natural terrain conditions to further enhance wave dissipation capacity and overall system attenuation performance.

[0028] The beneficial effects of this invention are:

[0029] This invention constructs a natural quasi-periodic elastic structure consisting of a density-gradient tree distribution area and a periodic shape tree array area, forming a "green isolation zone" that has a disturbance, scattering and energy dissipation effect on seismic wave propagation, which can significantly improve the attenuation efficiency of seismic waves.

[0030] Compared to traditional seismic isolation devices that rely on artificial damping elements or rigid support structures, the seismic isolation and damping system constructed in this invention has significant advantages such as being green and environmentally friendly, having strong ecological compatibility, requiring no external energy consumption, being easy to construct, and having low maintenance costs. It is particularly suitable for ecologically sensitive areas, mountainous regions, rural areas, and other areas with limited resources or high environmental requirements. Simultaneously, by utilizing the Bragg scattering mechanism achieved through periodic deployment and the impedance matching mechanism achieved through gradual density changes, shear waves and surface waves can be effectively weakened across multiple frequency bands, improving the safety and resilience of the structure under seismic loading. Furthermore, as trees grow over time, their trunk stiffness and root system range continuously increase, making the damping performance evolve and be sustainable, providing a new path for constructing low-carbon, ecological, and resilient earthquake-resistant and disaster-mitigation infrastructure. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of a seismic isolation and damping system based on the spatial arrangement of trees.

[0032] Figure 2 A top view of the area with gradually varying tree density and the area with periodic, shaped tree arrays.

[0033] Figure label:

[0034] 1. Seismic waves;

[0035] 2. Trees in areas with gradually changing density; 21. Trees within areas with gradually changing density;

[0036] 3. Periodic morphological tree array area; 31. Trees within the periodic morphological tree array area;

[0037] 4. Buffer transition zone; 41. Trees within the buffer transition zone; 42. Flexible root network structure within the buffer transition zone;

[0038] 5. Target protection zone. Detailed Implementation

[0039] The technical solutions provided in this application will be further described below with reference to specific embodiments and accompanying drawings. The advantages and features of this application will become clearer from the following description.

[0040] Example

[0041] This implementation describes a seismic isolation and damping system based on a spatially distributed tree arrangement. It is suitable for regions where the dominant seismic frequency is concentrated in the 3–12 Hz range, such as most mountainous and rural areas of China. The design can be adjusted to suit specific site conditions. Those skilled in the art, guided by this invention, can implement the system through calculation, analysis, and engineering experiments based on existing geological data, construction experience, and structural response requirements, without affecting the scope of protection of this invention.

[0042] like Figure 1 As shown, the present invention provides a seismic isolation and damping system based on the spatial arrangement of trees, which includes, in sequence along the propagation direction of seismic wave 1: a density-gradient tree arrangement zone 2, a periodic shape tree array zone 3, a buffer transition zone 4, and a target protection zone 5.

[0043] Specifically, the density-gradient tree deployment zone 2 is located at the foremost end of the proposed seismic isolation and damping system, facing the direction of potential seismic wave incidence. Within the density-gradient tree deployment zone, the density of trees 21 gradually increases along the direction of seismic wave propagation, forming a wave impedance gradient layer, which can effectively reduce interface reflection and guide seismic waves into the rear periodic shape tree array zone 3.

[0044] In this embodiment, the trees 21 in the density-gradient tree layout area are arranged parallel to the direction of seismic wave propagation; the initial spacing of the trees 21 in the density-gradient tree layout area is approximately 2.5 meters, gradually decreasing to 1.5 meters inwards along the direction of seismic wave propagation, such as... Figure 2 As shown in (a), the trees 21 in the density gradient tree layout area are selected from trees with shallow roots, greater flexibility and easy survival (such as poplar). The layout can be staggered or non-uniformly progressive to break the consistency of the wave path and improve the overall wave scattering effect. The layout length can be set to 10 to 15 meters and the number of rows can be 3 to 4.

[0045] Specifically, the periodic shape tree array area 3 is set after the density gradient tree layout area 2 and is arranged as a two-dimensional equally spaced elastic periodic structure to induce the Bragg scattering effect, form a seismic gap, and then generate reflection and scattering effects on shear waves and surface waves in a specific frequency range.

[0046] In this embodiment, the trees 31 in the periodic shaped tree array area are arranged at equal intervals of 1.0 to 1.2 meters, and the arrangement can be square, hexagonal, or staggered grid, such as... Figure 2As shown in (b), in order to adapt to the propagation path of seismic waves with different incident angles and improve the wave energy interference capability; in the periodic shape tree array area, trees 31 with well-developed root systems and high trunk stiffness (such as locust trees and goldenrain trees) are selected to enhance the array structure's ability to disturb and reflect seismic waves; the array parameter design satisfies the Bragg scattering condition, i.e., formula (1); in order to broaden the effective band gap range and enhance the multi-band wave energy attenuation capability, an interlaced arrangement can be adopted to break the consistency of the structure's periodicity; the array length is 10 to 30 meters, and the number of rows and columns can be adjusted according to the site and the protection target.

[0047] Specifically, the target protection area 5 is set after the periodic shaped tree array area 3, and serves as the core protected area in this system, used to deploy engineering buildings and their ancillary facilities, such as residences, schools, hospitals, and power facilities.

[0048] In this embodiment, the target protection zone 5 does not directly install energy-dissipating components. Instead, it relies on the progressive attenuation and reflection of incident seismic waves by the gradually varying density of the tree planting area 2 and the periodic, shaped tree array area 3, thereby reducing the intensity of ground motion entering the protection zone. Buildings within the target protection zone 5 do not require additional traditional seismic isolation bearings, thus reducing engineering costs. Depending on engineering requirements, the boundary of the protection zone can be optimized to further enhance its ability to absorb and control aftershocks.

[0049] Specifically, the buffer transition zone 4 is set between the periodic shape tree array area 3 and the target protection area 5 to absorb the seismic wave energy that is not completely dissipated in the periodic array area and reduce the problem of local acceleration amplification caused by reflection, interference and other effects.

[0050] In this embodiment: the buffer transition zone 4 can be set as an open area with a width of 5 to 10 meters. The layout includes: setting trees 41 in the buffer transition zone, such as low-density shrubs, grasslands or shallow-rooted vegetation, to form a natural energy-dissipating cover; a flexible root network structure 42 (such as vegetation blankets or artificial net bundles) can be buried underground in the buffer transition zone to generate shear slip and friction energy dissipation when the wave passes through.

[0051] Furthermore, numerical simulation platforms based on the finite element method (FEM) (such as ABAQUS, COMSOL, etc.) can be used to evaluate the response effect of the system of the present invention, so as to optimize the layout density, arrangement and array geometry, and ensure that the system achieves good fluctuation control effect within the target frequency range.

[0052] The above description is merely a description of preferred embodiments of this application and is not intended to limit the scope of this application in any way. Any changes or modifications made by those skilled in the art based on the above-disclosed technical content should be considered as equivalent and valid embodiments and fall within the scope of protection of the technical solution of this application.

Claims

1. A seismic isolation and damping system based on the spatial arrangement of trees, characterized in that, It includes a density gradient tree layout area (2), a periodic character tree array area (3), a buffer transition zone (4), and a target protection area (5), wherein: The density gradient tree layout area (2) is located at the front end of the seismic isolation and damping system, facing the direction of potential seismic wave incidence. The tree density gradually increases along the direction of seismic wave propagation. It is used to construct a flexible transition zone with wave impedance gradient characteristics, realize a smooth impedance transition, thereby reducing the reflection intensity of the incident wave and guiding the wave energy into the rear periodic shape tree array area (3). The periodic shape tree array area (3) is set after the density gradient tree layout area (2). The trees are arranged at equal intervals to form a two-dimensional elastic periodic structure, which triggers the Bragg scattering effect in a specific frequency band, effectively reflects and dissipates incident seismic waves, and realizes the wave propagation suppression function in the target frequency band. The buffer transition zone (4) is set between the periodic shape tree array area (3) and the target protection area (5) to further absorb the seismic wave energy that the periodic structure has not completely dissipated, and reduce the reflection and interference superposition effect of seismic waves in this area. The target protection area (5) is located after the periodic character tree array area (3) and serves as the core protected area in the seismic isolation and damping system, used to deploy the engineering buildings and building complexes to be protected.

2. The seismic isolation and damping system based on the spatial arrangement of trees as described in claim 1, characterized in that, The specific layout method of the density gradient tree layout area (2) is as follows: A density-gradient tree planting area is set up on the side closest to the direction of seismic wave incidence; The spacing between trees was gradually reduced along the direction of seismic wave propagation. Tree species with shallow and flexible root systems are selected for planting to enhance the adaptability and deformation capacity of the structure, forming a flexible, gradually changing medium layer that can buffer fluctuations and guide energy propagation.

3. The seismic isolation and damping system based on the spatial arrangement of trees as described in claim 1, characterized in that, The specific layout of the periodic character-shaped tree array area (3) is as follows: After the area of ​​trees with gradually varying density, a grid-like array of trees with equal spacing is laid out, which serves as the main wave scattering and reflection functional structure in the seismic isolation and damping system. Array spacing d The design should be based on the target bandgap frequency and should satisfy the Bragg scattering condition, as shown in formula (1): （1） In the formula, The wavelength of the seismic wave. θ Angle of incidence n It is an integer; The selected tree species are those with well-developed root systems and high trunk rigidity to enhance their ability to resist and reflect seismic waves. The deployment pattern adopts a square, hexagonal, or staggered layout to adapt to multi-directional wave propagation and expand the bandwidth range.

4. A seismic isolation and damping system based on a spatial tree arrangement as described in claim 1, characterized in that, Under the action of seismic motion, the front density gradient tree layout area and the periodic shape tree array area form a cooperative impedance system, which together weakens the kinetic energy density of seismic waves during propagation, reduces the seismic motion intensity entering the target protection area (5), and thus improves the seismic safety of structures in the target protection area.

5. A seismic isolation and damping system based on a spatial tree arrangement as described in claim 1, characterized in that, The buffer transition zone (4) is specifically arranged as follows: A buffer zone of a certain width is reserved between the end of the periodic tree array area and the target protection area as an energy attenuation zone to absorb residual fluctuation energy. Additional damping devices are designed in conjunction with the underground shallow root system structure or natural terrain conditions to further enhance the wave dissipation capacity and the overall attenuation performance of the system.

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