Wall vibration isolation system suitable for periodic bending of high and steep roadbed fill slope

Abstract

The invention discloses a wall vibration isolation system suitable for periodic bending of a high and steep roadbed fill slope, which comprises a plurality of vibration isolation structure units arranged according to a period, each vibration isolation structure unit comprises a straight wall (1), an upper covering plate (2), a middle covering plate (3) and a bottom plate (4), and effective control of Rayleigh waves is realized through a specific structure size and arrangement mode; the straight wall (1) is a main body part of the vibration isolation structure unit, is arranged perpendicular to the ground and is used for reflecting a horizontal component of Rayleigh waves; the upper covering plate (2) is of a plate-shaped structure horizontally extending from the top of the straight wall (1) to the vibration source direction and is used for enhancing constraint of a top soil body and a wall body. The middle covering plate (3) is arranged at the middle position of the straight wall (1), horizontally extends towards the direction of a vibration source, is in synergistic effect with the upper covering plate (2), and is used for segmenting the influence range of Rayleigh waves; the bottom plate (4) is arranged at the bottom of the straight wall (1), horizontally extends towards the two sides and is used for restraining displacement of the bottom of the straight wall and promoting conversion from surface waves to body waves.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high and steep embankment slope vibration isolation and damping safety protection technology, in particular to a wall vibration isolation system suitable for periodic bending of high and steep embankment slope. BACKGROUND

[0002] When the train passes, the vibration energy is mainly released outward in the form of Rayleigh wave, shear wave and compression wave, among which Rayleigh wave accounts for 67% of the total energy and has an influence depth of about 2 times the wavelength. In high and steep embankment, when Rayleigh wave reaches the surface of embankment slope, due to the difference of medium, Rayleigh wave will be totally reflected, thereby forming a larger reflected stretching wave on the surface of the slope. The effect of the stretching wave will threaten the safety and stability of the slope over time; secondly, under the action of rainfall, rainwater is easy to accumulate on the surface of the slope, and when Rayleigh wave reaches the surface of the slope, the "compression" and the "stretching" of the reflected Rayleigh wave will accelerate the formation and effect depth of the saturated zone on the surface of the slope, threatening the stability of the slope.

[0003] Therefore, how to effectively control the propagation of Rayleigh wave to the slope direction after the train runs is of great significance to the safety and stability of high and steep embankment slope.

[0004] The current common vibration isolation structure includes ditch, wall and row pile. Generally, the isolation effect of ditch is the best, but the ditch itself has no strength or small strength (filled ditch), which obviously cannot meet the high strength and stiffness requirements of embankment. Row pile has the advantages of large construction depth and strong environmental adaptability, but row pile belongs to non-continuous vibration isolation barrier, and wall belongs to continuous vibration isolation barrier, so the isolation effect of wall is better.

[0005] Most of the existing vibration isolation walls belong to cast-in-place walls, that is, a ditch is first dug on the foundation, and then the wall is constructed by filling. Due to the constraints of construction technology and geological environment, the current vibration isolation wall is mostly a straight wall, and the influence of wall characteristics on vibration isolation effect is rarely considered. In view of the application scene of high and steep filling slope of railway embankment, which belongs to post-filling engineering, the characteristics of the wall can be fully considered to achieve better vibration isolation effect.

[0006] As known, Rayleigh wave is a structure surface coupling of horizontally polarized P wave and vertically polarized SH. When the incident Rayleigh wave reaches the wall surface, the horizontal component of the wave is reflected back to form a reflected surface wave; the vertical component of the wave turns to the deep part of the foundation to form a body wave. In order to obtain better vibration isolation effect, both the horizontal component and the vertical component of Rayleigh wave must have good constraint. However, the existing technology has the following technical defects: (1) For the horizontal component of Rayleigh wave, although the horizontal component of Rayleigh wave is perpendicular to the wall, the wave has a good reflection effect in the azimuth. However, the compaction degree of the railway subgrade is large, and the mechanical performance parameters of the subgrade and the wall are small, the single-row wall has limited reflection wave capacity, and the multi-row wall lacks effective theoretical design method.

[0007] (2) For the vertical component of Rayleigh wave, the vertical constraint of the straight wall is provided by the friction between the wall and the soil, and the friction constraint of the straight wall itself is weak. On the one hand, if the top wall-soil friction constraint is insufficient, the surface wave is effectively converted into a body wave; on the other hand, due to the constraint of the wall structure itself, the construction depth of the wall itself is not large (compared with the pile), if the bottom wall-soil friction constraint is insufficient, the wall will move together with the soil, and the wall is virtual. In addition, the constraint range of the straight wall and the soil is limited to a very small area around the wall, and most of the area between the walls has no vertical constraint. Therefore, the current design of the straight wall is insufficient for the vertical component of the wave. SUMMARY

[0008] The purpose of the present application is to provide a wall vibration isolation system suitable for periodic bending of high and steep subgrade filling slope, for the vertical and horizontal components of Rayleigh wave, considering that Rayleigh wave only exists in the ground down 1-2 times the wavelength, a new vibration isolation device and its arrangement form are proposed, the causes and propagation characteristics of Rayleigh wave are fully considered, the vertical and horizontal components of Rayleigh wave are controlled from the structure and method, and the long-term safety and stability of the high and steep filling subgrade slope is significantly improved by innovative structure design and periodic arrangement form.

[0009] The purpose of the present application is to provide a wall vibration isolation system suitable for periodic bending of high and steep subgrade filling slope, for the vertical and horizontal components of Rayleigh wave, considering that Rayleigh wave only exists in the ground down 1-2 times the wavelength, a new vibration isolation device and its arrangement form are proposed, the causes and propagation characteristics of Rayleigh wave are fully considered, the vertical and horizontal components of Rayleigh wave are controlled from the structure and method, and the long-term safety and stability of the high and steep filling subgrade slope is significantly improved by innovative structure design and periodic arrangement form. A plurality of vibration isolation structure units arranged in cycles, the vibration isolation structure unit comprising a straight wall (1), an upper cover plate (2), a middle cover plate (3) and a bottom plate (4), and realizing effective control of Rayleigh wave through specific structure size and arrangement mode; wherein: The straight wall (1) is the main part of the vibration isolation structure unit, which is arranged vertically to the ground and used for reflecting the horizontal component of Rayleigh wave; the upper cover plate (2) is a plate-shaped structure horizontally extending from the top of the straight wall (1) to the vibration source direction and used for enhancing the constraint of the top soil and the wall; the middle cover plate (3) is arranged at the middle position of the straight wall (1), horizontally extends to the vibration source direction and cooperates with the upper cover plate (2), and is used for dividing the influence range of Rayleigh wave; and the bottom plate (4) is arranged at the bottom of the straight wall (1) and horizontally extends to both sides, and is used for constraining the displacement of the bottom of the straight wall and promoting the conversion of surface wave to body wave. The upper cover plate (2) is fixedly connected with the top of the straight wall (1) to form a T-shaped structure; the middle cover plate (3) is fixedly connected with the middle of the straight wall (1) and is located below the upper cover plate (2); and the bottom plate (4) is fixedly connected with the bottom of the straight wall (1) to form an inverted T-shaped structure; and the upper cover plate (2), the middle cover plate (3) and the bottom plate (4) are all located on the same side of the straight wall (1), that is, the side facing the vibration source.

[0010] As a preferred embodiment, the vibration isolation system is arranged between the vibration source and the protected area in a periodic arrangement mode of multiple rows of vibration isolation structure units; wherein: The horizontal spacing L between each vibration isolation structure unit is set to 2 , wherein represents the wavelength of Rayleigh wave at the main frequency of the subgrade slope, the horizontal spacing L is , and the vertical spacing S is set to 2 , so that the transmission wave and the reflection wave can produce destructive interference based on the Bragg scattering mechanism in the periodic structure theory.

[0011] As a preferred embodiment, the number n of rows of the vibration isolation structure units is determined by numerical simulation optimization according to the measured vibration acceleration amplitude and in reference to the allowable vibration acceleration amplitude.

[0012] As a preferred embodiment, the vibration isolation structure unit is prefabricated by reinforced concrete.

[0013] As a preferred embodiment, the height H of the straight wall (1) is set to 3 -4 , so as to ensure that the depth of the straight wall (1) exceeds the influence depth 1 -2 of Rayleigh wave, and guarantee the basic vibration isolation effect.

[0014] As a preferred embodiment, the width a of the upper cover plate and the width b of the middle cover plate are both set to 0.8 -1 This increases the constraint effect between the soil and the wall by increasing the contact area.

[0015] In a preferred embodiment, the distance c between the upper cover plate (2) and the middle cover plate (3) is set to 0.5. -1 This effectively segments the influence range of the Rayleigh wave.

[0016] In a preferred embodiment, the width d of the base plate (4) is set to 1. -1.5 This provides sufficient bottom constraints.

[0017] In a preferred embodiment, the longitudinal section of the vibration isolation structure unit is rectangular, and the longitudinal length M of the vibration isolation structure unit is determined according to the lifting weight of the construction equipment and is adjusted within the range of 1-5m according to the construction conditions.

[0018] In a preferred embodiment, the thickness w1 of the straight wall (1) is set to 0.2-0.3m; the thickness w2 of the upper cover plate (2) is set to 0.1-0.15m; the thickness w3 of the middle cover plate (3) is set to 0.1-0.15m; and the thickness w4 of the bottom plate (4) is set to 0.2-0.3m.

[0019] The beneficial effects of the wall vibration isolation system of the present invention are as follows: 1. Vibration isolation of the vertical component of Rayleigh waves. Its isolation principle is based on the concept of surface waves and rotating body waves, and its specific beneficial effects are reflected in: (1) Two cover plates and one base plate were added to the straight wall. The cover plates can significantly increase the contact area between the soil and the wall, thereby improving the vertical constraint of the Rayleigh wave.

[0020] (2) The distance between the two covering plates is set to 0.5-1 times the Rayleigh wavelength, which can cut off the influence range of Rayleigh waves (1-2 wavelengths) and thus better disperse the force.

[0021] (3) The direction of the cover plate (only on one side of the straight wall) is opposite to the direction of wave propagation, which means that the cover plate only affects the incident wave and has little effect on the reflected wave. This helps the reflected wave to better penetrate into the depth of the roadbed, thereby reducing the impact of the reflected wave on the roadbed surface.

[0022] (4) The base plate is set with a large width (1.5-2 times the wavelength), which can constrain the displacement of the bottom of the straight wall to the maximum extent and cause the vertical component of the Rayleigh wave to be converted into a body wave.

[0023] (5) The depth of the straight wall is set to 3-4 times the wavelength, which exceeds the influence depth of Rayleigh waves (1-2 times the wavelength). Therefore, it can meet the basic vibration isolation effect. At the same time, the depth is limited and the self-weight is controllable, which is convenient for actual construction.

[0024] 2. Rayleigh horizontal component vibration isolation, its vibration isolation concept is based on the destructive interference of periodic structural waves, and its specific beneficial effects are reflected in: For the horizontal component of Rayleigh waves, the reflection capability of a single-row vibration isolation structure is limited. Therefore, a multi-row vibration isolation structure with a periodic arrangement is proposed. Based on the principle of periodic structures, the spacing between the rows of the vibration isolation structures is controlled, and the transmitted and reflected waves generate Bragg destructive interference, thereby constraining the propagation of the horizontal component of Rayleigh waves.

[0025] 3. Through testing and comparison of vibration isolation effects, when three rows of vibration isolation structures are arranged at the top of the slope, the vibration isolation structure and arrangement of the present invention have a significant improvement in vibration isolation performance compared with the straight wall vibration isolation structure. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is an overall diagram of a periodic bending wall vibration isolation structure provided according to an embodiment of the present invention.

[0028] Figure 2 This is a schematic cross-sectional view of a bending wall vibration isolation structure unit provided according to an embodiment of the present invention.

[0029] Figure 3 This is a longitudinal section schematic diagram of a vibration isolation structure unit provided according to an embodiment of the present invention.

[0030] Figure 4 This is a schematic diagram of the dimensions of a bending wall vibration isolation structure unit provided according to an embodiment of the present invention.

[0031] Figure 5 This is a schematic diagram comparing the vibration isolation effects provided by an embodiment of the present invention. Detailed Implementation

[0032] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0034] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] The following embodiments provide a Rayleigh wave vibration isolation structure adapted to steep railway subgrade slopes. Based on the characteristic of Rayleigh waves possessing both horizontal and vertical polarization, a step-by-step design is implemented. Considering the limited influence range of Rayleigh waves, a finite-length straight wall and base plate constraint are designed. The aim is to minimize the impact of Rayleigh waves on slope safety and stability. Utilizing the Bragg scattering mechanism in periodic structure theory, a periodic arrangement is invented to compensate for the insufficient horizontal vibration isolation of Rayleigh waves. Therefore, based on the combined horizontal and vertical polarization characteristics of Rayleigh waves, a paradigm of vertical surface wave / body wave-horizontal periodic vibration isolation is proposed, leading to the invention of a novel curved wall vibration isolation structure and its arrangement.

[0036] The greatest technological innovation of this invention lies in its application scenario of high embankment roadbeds, which allows for the prefabrication and construction of vibration isolation walls. This invention comprehensively considers the composition and propagation characteristics of Rayleigh waves, breaking free from the constraints of traditional straight walls. Furthermore, it incorporates special vibration isolation designs in both the horizontal and vertical directions of Rayleigh waves, achieving a comprehensive and excellent vibration isolation effect.

[0037] The design method for a wall vibration isolation system, based on existing roadbed slope vibration test frequencies and the physical and mechanical parameters of the roadbed fill soil, determines the design parameters, including the following steps: Step 1: Site Characteristics Analysis By conducting on-site tests in existing similar projects, the dominant vibration frequencies at different distances from the train track at specific train speeds were obtained, thus identifying the main influencing frequencies that may be present at the newly constructed steep embankment slopes. .

[0038] Step 2: Determining Soil Parameters: Laboratory tests were conducted on a portion of the compacted subgrade fill material from the site to obtain the subgrade's mechanical parameters, including the elastic modulus. ,density Compared to Poisson .

[0039] Step 3: Rayleigh wave parameter calculation: Based on elastic modulus ,density Poisson's ratio Calculate the Rayleigh wave velocity on the surface. As shown in equation (1): (1); in, The shear wave velocity is calculated using the formula shown in equation (2): (2); in, Shear modulus, and elastic modulus Compared to Poisson The relationship is shown in equation (3): (3); Step 4: Calculate the wavelength: Based on the frequency of the main influences and the surface Rayleigh wave velocity The corresponding wavelength λ is calculated as shown in equation (4): (4); Step 5: Determine the structural dimensions: Based on the calculated wavelength Determine the various dimensional parameters of the vibration isolation structure unit.

[0040] Step Six: Layout Optimization Based on the measured vibration acceleration amplitude and with reference to the allowable vibration acceleration amplitude (reference standard), the number of rows n and their arrangement positions of the vibration isolation structure units are preliminarily determined through numerical simulation.

[0041] In this embodiment, 3-4 rows are usually sufficient to achieve a good vibration isolation effect. If this vibration isolation structure is arranged in a multi-level slope, it should not be arranged at the top, bottom, or middle section of the slope.

[0042] Step Seven: Construction Implementation Based on the dimensions, precast reinforced concrete curved wall vibration isolation structural units are used, and construction and installation are carried out according to the determined layout plan.

[0043] Specifically, the objectives of the various embodiments include: 1. A novel vibration isolation structural unit is provided, which can effectively control both the vertical and horizontal components of Rayleigh waves simultaneously; 2. By setting up a cover plate and a base plate, the constraint between the soil and the wall is enhanced, promoting the conversion of surface waves into volume waves; 3. By utilizing periodic structure theory and rationally arranging multiple rows of vibration isolation structures, the destructive interference of the horizontal components of Rayleigh waves can be achieved; 4. Establish a complete design method for vibration isolation systems to provide theoretical basis and technical support for vibration control of steep embankment slopes.

[0044] like Figures 1-3 As shown: Example 1: Specific Implementation of Vibration Isolation Structure Unit refer to Figure 2 , Figure 3 and Figure 4 This embodiment details the specific construction of the vibration isolation structure unit.

[0045] The vibration isolation structural units are precast using C30 reinforced concrete, and all components are manufactured using an integral casting method to ensure the integrity of the structure. The reinforcement configuration complies with the relevant requirements of the "Code for Design of Concrete Structures" GB50010, with HRB400 grade steel bars used for the main load-bearing steel bars and HPB300 grade steel bars used for the structural steel bars.

[0046] 1. Straight wall 1 The straight wall is the main load-bearing part of the vibration isolation structure and adopts a rectangular cross-section. Its height H is determined according to the Rayleigh wavelength λ, and is usually taken as 3-4λ. Taking λ=2m as an example, the height H of the straight wall is 6-8m. The thickness w1 of the straight wall is 0.25m, which ensures sufficient stiffness while controlling the amount of material used.

[0047] The interior of the straight wall is equipped with a double-layer, two-way steel mesh. The vertical reinforcing bars are 16mm in diameter and spaced at 150mm; the horizontal reinforcing bars are 12mm in diameter and spaced at 200mm. The concrete cover is 40mm thick.

[0048] 2. Upper cover plate 2 The upper cover plate extends horizontally from the top of the straight wall towards the vibration source, with a width 'a' ranging from 0.8 to 1λ. Taking λ=2m as an example, the width 'a' ranges from 1.6 to 2m. The thickness 'w2' is 0.12m, employing a variable thickness design, thickening to 0.2m at the connection with the straight wall and gradually thinning to 0.1m at the ends.

[0049] The upper cover plate is internally equipped with a double-layer steel mesh. The main load-bearing steel bars are arranged along the width direction, with a diameter of 12mm and a spacing of 150mm; the distribution steel bars are arranged along the longitudinal direction, with a diameter of 10mm and a spacing of 200mm. Reinforcing steel bars with a diameter of 16mm and a spacing of 150mm are provided at the connection with the straight wall.

[0050] 3. Middle Cover Plate 3 The middle cover plate is set in the middle of the straight wall, at a distance of H / 2 from the top of the straight wall. Its dimensions and reinforcement are basically the same as those of the upper cover plate, with a width b of 0.8-1λ and a thickness w3 of 0.12m.

[0051] Diagonal reinforcing bars with a diameter of 14mm and a spacing of 150mm are installed at the connection between the central cover plate and the straight wall to ensure the reliability of the connection.

[0052] 4. Base plate 4 The base plate is set at the bottom of the straight wall and extends horizontally to both sides, with a width d of 1-1.5λ. Taking λ=2m as an example, the width d is 2-3m. The thickness w4 is 0.25m, adopting a uniform thickness design.

[0053] The base slab is internally reinforced with a double-layer steel mesh. The main load-bearing steel bars are arranged along the width direction, with a diameter of 16mm and a spacing of 150mm; the distribution steel bars are arranged along the longitudinal direction, with a diameter of 12mm and a spacing of 200mm. At the connection with the straight wall, additional steel bars are provided, with a diameter of 16mm and a spacing of 100mm.

[0054] 5. Connection Structure The connections between components are made using a monolithic cast-in-place method to ensure structural integrity. Additional reinforcing steel bars are installed at the connection points. (1) At the connection between the straight wall and the cover plate: 45° diagonal steel bars with a diameter of 14mm and a spacing of 150mm are installed; (2) At the connection between the straight wall and the bottom slab: L-shaped reinforcing bars with a diameter of 16mm and a spacing of 150mm are installed.

[0055] Example 2: Specific Implementation of Periodic Arrangement refer to Figure 1 This embodiment details the periodic arrangement of the vibration isolation system.

[0056] 1. Location arrangement The vibration isolation system is placed between the vibration source (railway track) and the protected area (slope). The horizontal distance from the track is determined according to the specific engineering conditions, usually 10-30m.

[0057] 2. Arrangement method The vibration isolation structural units are arranged in a rectangular grid with a lateral spacing (perpendicular to the track direction) of L, which is taken as 2λ; and a longitudinal spacing (parallel to the track direction) of M, which is the longitudinal length of the vibration isolation structural unit.

[0058] Taking λ=2m as an example: (1) Lateral spacing L = 2 × 2 = 4 m; (2) Longitudinal spacing M = 3m (determined based on the lifting capacity of the construction equipment); (3) The longitudinal length covered by each vibration isolation structural unit is 3m.

[0059] 3. Determine the number of rows The number of rows, n, is determined based on a comprehensive consideration of vibration control requirements and economic benefits. The vibration isolation effect under different numbers of rows is analyzed through numerical simulation to select the optimal number of rows.

[0060] The general principles for choosing the number of rows are as follows: (1) For general vibration control requirements: n = 2-3 rows; (2) For higher vibration control requirements: n = 3-4 rows; (3) For projects with special requirements: n ≥ 4 rows 4. Slope adaptability For multi-level slopes, the vibration isolation system should be placed in an appropriate location on the slope: (1) It should not be arranged at the top, bottom, or middle section of the slope; (2) Prioritize selecting stable areas of the slope; (3) Consider the overall stability of the slope and avoid affecting the safety of the slope due to the installation of the vibration isolation system.

[0061] Example 3: Specific Implementation of the Design Method This embodiment uses a steep embankment slope of a high-speed railway as an example to illustrate the design method of the present invention in detail.

[0062] Step 1: Site Characteristics Analysis In similar engineering projects, field vibration tests were conducted, and the dominant frequency of ground vibration at a distance of 20m from the track was measured when a train passed at a speed of 250km / h. .

[0063] Step 2: Determining Soil Parameters The mechanical parameters of the roadbed fill material were obtained through indoor tests: (1) Elastic modulus ; (2) Density ; (3) Poisson's ratio .

[0064] Step 3: Rayleigh wave parameter calculation First, calculate the shear modulus. : ; Calculate shear wave velocity : ; Calculate Rayleigh wave velocity : ; Step 4: Wavelength Calculation ; Step 5: Determine structural dimensions According to wavelength =11.38m, determine the dimensions of each component: The height of the straight wall is H=3.5. =3.5×11.38=39.83m, take 40m; The width of the upper cover plate is a = 0.9. =0.9×11.38=10.24m, take 10m; The width of the middle cover plate is b=0.9 =10.24m, take 10m; The spacing between the cover plates is c=0.7. =0.7×11.38=7.97m, take 8m; The width of the base plate is d=1.2 =1.2×11.38=13.66m, take 14m; The thickness of the straight wall is w1 = 0.25m; The thickness of the cover plate is w2=w3=0.12m; The thickness of the base plate is w4 = 0.25m; Longitudinal length M = 3m (determined based on construction equipment capacity) Step Six: Layout Optimization Numerical simulation analysis was conducted to analyze the vibration isolation effect under different row numbers: Row 1: Insertion loss approximately 8dB; 2 rows: Insertion loss approximately 15dB; 3 rows: Insertion loss approximately 21 dB; 4 rows: Insertion loss approximately 25dB; Considering both engineering economy and vibration isolation effect, n=3 rows are selected.

[0065] Lateral spacing L=2 =2×11.38=22.76m, take 23m.

[0066] Step Seven: Construction Implementation 1. Fabricate vibration isolation structural units in the prefabrication yard according to the design dimensions; 2. Excavate the foundation at the construction site to ensure the base is flat; 3. Large hoisting equipment is used for the installation of vibration isolation structure units; 4. After the unit is in place, backfill soil is constructed and compacted in layers; 5. Complete the construction of the entire vibration isolation system.

[0067] Example 4: Verification of Vibration Isolation Effect To verify the vibration isolation effect of the present invention, a detailed numerical simulation analysis was conducted.

[0068] 1. Analysis Model Establishing a three-dimensional finite element model includes: (1) Subgrade soil layer: The Mohr-Coulomb constitutive model was adopted; (2) Vibration isolation structure: adopts a linear elastic constitutive model; (3) Vibration input: simulates train moving load 2. Comparison of Schemes Three comparison schemes are set up: Option A: No vibration isolation measures; Option B: Traditional straight wall vibration isolation (height 40m, thickness 0.5m); Option C: Vibration isolation system of the present invention 3. Analysis Results Monitoring points were set up on the slope surface 30m away from the track to analyze the vibration response. (1) Comparison of vibration acceleration levels (center frequency of 12Hz in 1 / 3 octave band): Option A: 85dB; Option B: 76dB (reduced by 9dB); Option C: 64dB (reduced by 21dB) (2) Comparison of slope surface displacement: Option A: Maximum displacement 2.8mm; Option B: Maximum displacement 1.9mm; Option C: Maximum displacement 0.7mm 4. Results Analysis The analysis results show that: (1) Compared with no vibration isolation measures, the vibration acceleration level of the vibration isolation system of the present invention is reduced by 21dB, which is a significant effect; (2) Compared with traditional straight wall vibration isolation, the vibration control effect is improved by 12dB; (3) The surface displacement of the slope is greatly reduced, which is conducive to the long-term stability of the slope.

[0069] Example 5: Construction Quality Control To ensure the construction quality of the vibration isolation system, strict quality control measures were established: 1. Precast quality control (1) Concrete strength: not less than 110% of the design strength; (2) Thickness of concrete cover for reinforcing bars: deviation not exceeding ±5mm; (3) Component dimensions: deviation not exceeding ±10mm.

[0070] 2. Installation quality control (1) Positioning accuracy: The deviation of the plane position shall not exceed ±50mm, and the deviation of the elevation shall not exceed ±20mm; (2) Verticality: The deviation shall not exceed 1 / 500; (3) Height difference between adjacent units: not more than 10mm.

[0071] 3. Backfilling quality control (1) Backfill material: consistent with the roadbed fill material; (2) Compaction degree: not less than 96%; (3) Layer thickness: not exceeding 300mm.

[0072] Example 6: Long-term monitoring and maintenance To ensure the long-term effectiveness of the vibration isolation system, a complete monitoring and maintenance system has been established: 1. Monitoring Content (1) Vibration monitoring: Vibration monitoring points are set up before and after the vibration isolation system; (2) Displacement monitoring: Monitoring the displacement of the vibration isolation structural units and the slope; (3) Structural health monitoring: monitoring the stress state of the vibration isolation structural unit.

[0073] 2. Monitoring frequency (1) Construction period: Daily monitoring; (2) Initial stage of operation: Weekly monitoring; (3) Normal operation period: monthly monitoring.

[0074] 3. Maintenance Measures (1) Regular inspection: A comprehensive inspection shall be conducted every six months; (2) Timely repair: Repair any damage promptly upon discovery; (3) Data update: Optimize the maintenance plan based on monitoring data.

[0075] Compared with the prior art, this embodiment has the following significant advantages: 1. Highly targeted: It is specifically designed for the propagation characteristics of Rayleigh waves in steep embankment slopes, and fully considers the characteristics of Rayleigh waves having both horizontal and vertical polarization, thus achieving effective control of the two components.

[0076] 2. Significant vibration isolation effect: The setting of the cover plate and the bottom plate significantly enhances the constraint between the soil and the wall, effectively promoting the conversion of surface waves into volume waves; By utilizing a periodic arrangement, destructive interference of the horizontal components of Rayleigh waves was achieved based on the Bragg scattering mechanism. like Figure 5 As shown, compared with the traditional straight wall vibration isolation structure, the vibration isolation effect of the present invention is significantly improved.

[0077] 3. Reasonable structure: The cover plate is only installed on one side of the straight wall, opposite to the direction of wave propagation, and only affects the incident wave, which helps the reflected wave to better penetrate into the depth of the roadbed; The spacing between the cover plates is set to 0.5-1 times the Rayleigh wavelength, which effectively segments the influence range of the Rayleigh wave; The base plate width is set to 1.5-2 times the wavelength, providing sufficient bottom constraint.

[0078] 4. Convenient construction: The vibration isolation structure units are prefabricated, which facilitates quality control. The longitudinal length is determined based on the lifting weight of the construction equipment to adapt to on-site construction conditions; The depth is controlled at 3-4 times the wavelength, the weight is controllable, and it is convenient for actual construction.

[0079] 5. Scientific Design: It provides a complete design methodology, with clear technical guidance for each stage, from site characteristic analysis to final construction implementation; Based on the theory of periodic structures, a theoretical basis is provided for the arrangement of multi-row vibration isolation structures.

[0080] 6. Good economic benefits: While ensuring vibration isolation, the amount of material used was reduced through optimized design; Prefabrication construction methods improve construction efficiency and reduce project costs.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wall vibration isolation system suitable for the periodic bending of steep roadbed embankment slopes, characterized in that, include: Multiple vibration isolation structural units arranged periodically, each unit comprising a straight wall (1), an upper cover plate (2), a middle cover plate (3), and a bottom plate (4), achieve effective control of Rayleigh waves through specific structural dimensions and arrangement; wherein: The straight wall (1) is the main body of the vibration isolation structure unit, and is set perpendicular to the ground to reflect the horizontal component of Rayleigh waves; the upper cover plate (2) is a plate-like structure that extends horizontally from the top of the straight wall (1) toward the vibration source to enhance the constraint between the top soil and the wall; the middle cover plate (3) is set in the middle of the straight wall (1), extends horizontally toward the vibration source and works in conjunction with the upper cover plate (2) to divide the influence range of Rayleigh waves; the bottom plate (4) is set at the bottom of the straight wall (1), extends horizontally to both sides to constrain the displacement of the bottom of the straight wall and promote the conversion of surface waves into volume waves; The upper cover plate (2) is fixedly connected to the top of the straight wall (1) to form a T-shaped structure; the middle cover plate (3) is fixedly connected to the middle of the straight wall (1) and is located below the upper cover plate (2); the bottom plate (4) is fixedly connected to the bottom of the straight wall (1) to form an inverted T-shaped structure; the upper cover plate (2), the middle cover plate (3) and the bottom plate (4) are all located on the same side of the straight wall (1), that is, the side facing the vibration source.

2. The wall vibration isolation system suitable for the periodic bending of steep roadbed embankment slopes according to claim 1, characterized in that, The vibration isolation system employs multiple rows of vibration isolation structural units arranged periodically between the vibration source and the protected area; wherein: The horizontal spacing L between each vibration isolation structural unit is set to 2. ,in This represents the wavelength of the Rayleigh wave at the dominant frequency of the roadbed slope, and the horizontal spacing. Set to 2 This allows for destructive interference between transmitted and reflected waves, based on the Bragg scattering mechanism in periodic structure theory.

3. A wall vibration isolation system suitable for the periodic bending of steep roadbed embankment slopes according to claim 2, characterized in that, Based on the measured vibration acceleration amplitude and with reference to the allowable vibration acceleration amplitude, the number of rows n of the vibration isolation structure unit is determined through numerical simulation optimization.

4. A wall vibration isolation system suitable for periodic bending of steep roadbed embankment slopes according to claim 3, characterized in that, The vibration isolation structure unit is prefabricated from reinforced concrete.

5. A wall vibration isolation system suitable for periodic bending of steep roadbed embankment slopes according to claim 4, characterized in that, The height H of the straight wall (1) is set to 3. -4 This ensures that the depth of the straight wall (1) exceeds the influence depth of the Rayleigh wave by 1. -2 This ensures basic vibration isolation.

6. A wall vibration isolation system suitable for the periodic bending of steep roadbed embankment slopes according to claim 5, characterized in that, The width 'a' of the upper cover plate and the width 'b' of the middle cover plate are both set to 0.

8. -1 This increases the constraint effect between the soil and the wall by increasing the contact area.

7. A wall vibration isolation system suitable for periodic bending of steep roadbed embankment slopes according to claim 6, characterized in that, The distance c between the upper cover plate (2) and the middle cover plate (3) is set to 0.

5. -1 This effectively segments the influence range of the Rayleigh wave.

8. A wall vibration isolation system suitable for periodic bending of steep roadbed embankment slopes according to claim 7, characterized in that, The width d of the base plate (4) is set to 1. -1.5 This provides sufficient bottom constraints.

9. A wall vibration isolation system suitable for periodic bending of steep roadbed embankment slopes according to claim 8, characterized in that, The longitudinal section of each vibration isolation structure unit is rectangular, and the longitudinal length M of the vibration isolation structure unit is determined according to the lifting weight of the construction equipment and is adjusted within the range of 1-5m according to the construction conditions.

10. A wall vibration isolation system suitable for periodic bending of steep roadbed embankment slopes according to claim 9, characterized in that, The thickness w1 of the straight wall (1) is set to 0.2-0.3m; the thickness w2 of the upper cover plate (2) is set to 0.1-0.15m; the thickness w3 of the middle cover plate (3) is set to 0.1-0.15m; and the thickness w4 of the bottom plate (4) is set to 0.2-0.3m.

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