Pile-in-row vibration isolation method and pile-in-row vibration isolation system

Abstract

The invention provides a row pile vibration isolation method and a row pile vibration isolation system, and relates to the technical field of civil engineering. The method comprises the following steps: S1, designing various parameters of the row pile vibration isolation system; s2, vibration isolation piles in the row pile vibration isolation system are prepared; s3, constructing and installing a row pile vibration isolation system; and S4, carrying out a vibration test on the pile-in-row vibration isolation system and evaluating a vibration isolation effect. According to the method, a large amount of earthwork operation is not needed, the construction cost is greatly reduced, meanwhile, the excellent vibration isolation effect on broadband vibration (1Hz-100Hz) caused by traffic loads is achieved, and particularly the low-frequency vibration isolation performance which is difficult to process through a traditional method is improved.

Description

Technical Field

[0001] This application relates to the field of civil engineering, and in particular to a pile vibration isolation method and a pile vibration isolation system. Background Technology

[0002] With the rapid development of high-tech industries such as semiconductor manufacturing, biomedicine, and precision optics, the requirements for the production environment are becoming increasingly stringent. In particular, the micro-vibration control of the factory floor has become a key factor directly affecting the imaging quality, production stability, and product yield of precision equipment such as lithography machines and electron microscopes.

[0003] Among various environmental vibration sources, road traffic loads are a major and difficult-to-avoid source. Vibration waves generated by vehicles propagate through the foundation soil in all directions, posing a continuous threat to nearby high-tech factories.

[0004] Currently, common vibration isolation measures include: (1) Setting up vibration isolation trenches: excavating trenches filled with elastic material between the vibration source and the building. This method has limited vibration isolation effect for low-frequency vibrations, and deep trenches have problems such as construction difficulties, poor stability, and impact on surrounding underground pipelines. (2) Using conventional pile barriers: driving one or more rows of concrete piles or steel piles between the vibration source and the protected area to form wave barriers. This method is more robust and durable than vibration isolation trenches. However, traditional piles are mainly made of high-impedance materials (such as concrete and steel), and their vibration isolation mechanism is mainly to reflect vibration waves through the difference in wave impedance. For low-frequency vibrations, the reflection effect is not good, and the piles may become new vibration transmission paths due to their high stiffness, resulting in unsatisfactory vibration isolation efficiency in certain frequency bands.

[0005] Therefore, there is an urgent need in this field for a vibration isolation solution that can effectively block mid-to-high frequency vibrations, significantly attenuate low-frequency vibrations, and is feasible to construct, economical, and durable. Summary of the Invention

[0006] One of the purposes of this application is to provide a pile vibration isolation method and a pile vibration isolation system, which aims to solve the problem of poor vibration isolation effect of existing pile vibration isolation systems.

[0007] The technical solution of this application is: A method for vibration isolation using pile banks includes the following steps: S1 represents the parameters for designing a pile isolation system; S2, Preparation of foamed plastic modified concrete; S3, Construction and installation of the pile vibration isolation system; S4, Conduct vibration tests on the pile isolation system and evaluate the vibration isolation effect.

[0008] As one technical solution of this application, step S1 specifically includes the following steps: Based on the usage function and vibration environment of the construction area, determine the pile diameter, pile length, number of rows, and spacing of the piles in the pile isolation system. The design incorporates alternating plum blossom-shaped pile arrangements to form the pile vibration isolation system. Design W-shaped connecting beams and straight connecting beams to connect the tops of the vibration isolation piles in the pile isolation system.

[0009] As one technical solution of this application, in the pile isolation system, the isolation piles are arranged in parallel at intervals, and the pile type includes circular bored cast-in-place piles or precast pipe piles; the pile diameter of the isolation pile is 0.6-1.2m, the pile length is 10-25m, and the center distance between adjacent isolation piles is 1.5-1.8 times the diameter of a single pile; the total number of rows of isolation piles is 3-7, and the length L of a single pile satisfies: λ R ≤L≤1.5λ R , where λ R The wavelength of Rayleigh is calculated using the formula λ. R =V s / f,V s denoted as the average shear wave velocity of the soil layer at the site, and f is the frequency of the main vibration source that needs to be isolated.

[0010] As one technical solution of this application, step S2 specifically includes the following steps: First, cement, sand, stone, water, and water-reducing agent are mixed to make concrete; then, a predetermined proportion of foamed plastic particles are added and mixed evenly at low speed to prepare foamed plastic modified concrete.

[0011] As one technical solution of this application, the foamed plastic particles are crushed waste polystyrene foam or polyurethane foam particles, and the particle size is 3mm~10mm.

[0012] As one technical solution of this application, the volume ratio of the foamed plastic particles to the concrete is 1:6 to 1:10.

[0013] As one technical solution of this application, the volume ratio of the foamed plastic particles to the concrete is 1:8.

[0014] As one technical solution of this application, step S3 specifically includes the following steps: At the construction site, mud slurry was used to protect the wall during drilling and to form pile holes; The reinforcing cage is placed inside the pile hole; The foamed plastic modified concrete is injected into the corresponding pile holes in layers to wrap the steel cage and form vibration isolation piles. Repeat the above steps until the construction of the pile vibration isolation system is completed.

[0015] As one technical solution of this application, step S4 specifically includes the following steps: After the construction of the pile isolation system is completed, vibration performance test is carried out: sensors are arranged on the preset vibration source side and the protected area side of the isolation piles in the pile isolation system, and sweep frequency vibration excitation is applied to measure and calculate the vibration attenuation of the pile isolation system at different frequencies. Based on the test results of the vibration attenuation of the pile isolation system at different frequencies, the frequency bands in which the vibration isolation effect of the pile isolation system does not meet the standard are identified. The vibration isolation characteristics of the pile isolation system are adjusted by selectively adjusting the pile spacing, pile length or pile material of the isolation piles in the pile isolation system, and repeated tests are conducted until the attenuation effect meets the design specifications. The adjusted pile vibration isolation system was verified on-site by means of static load test, low-cycle cyclic load test or setting long-term monitoring points to test the structural stability and durability of the pile vibration isolation system under different working conditions.

[0016] A pile vibration isolation system is constructed using the pile vibration isolation method described above.

[0017] The beneficial effects of this application are: (1) This application develops a pile isolation method, which, through reasonable construction design of the pile system structure, scientific material selection, and selection of appropriate vibration isolation pile structure and material ratio, combines the two mechanisms of material energy absorption (for low frequency) and structural reflection (for medium and high frequency), and has excellent vibration isolation effect on broadband vibration (1Hz~100Hz) caused by traffic load. In particular, it improves the low frequency vibration isolation performance that is difficult to handle by traditional methods, significantly improves the vibration isolation effect and long-term stability of the vibration isolation pile, and solves the problem of poor vibration isolation effect of existing construction vibration isolation pile structures.

[0018] (2) This application develops a pile isolation system, which combines two mechanisms, namely material energy absorption (for low frequency) and structural reflection (for medium and high frequency), by selecting appropriate vibration isolation pile structure, material ratio and pile arrangement method. It has excellent vibration isolation effect on broadband vibration (1Hz~100Hz) caused by traffic load, especially improving the low frequency vibration isolation performance that is difficult to handle by traditional methods, significantly improving the vibration isolation effect and long-term stability of the vibration isolation pile, and solving the problem of poor vibration isolation effect of existing vibration isolation pile structures. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the pile isolation method provided in the first embodiment of this application; Figure 2 This is a schematic diagram of the plan layout of the pile isolation system provided in the second embodiment of this application; Figure 3 This is a schematic cross-sectional view of the pile isolation system provided in the second embodiment of this application; Figure 4 A comparison curve of the vibration isolation effects of ordinary concrete piles provided in the third embodiment of this application and piles using the vibration isolation method in this embodiment.

[0021] Reference numerals: 1 - Vibration isolation pile. Detailed Implementation

[0022] In the description of this application, it should be noted that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use. They are only used to facilitate the description of this application and to simplify 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 this application.

[0023] Furthermore, in this application, unless otherwise expressly specified and limited, "above or below" the first feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. Moreover, "above," "over," and "on" the first feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the first feature includes the first feature located at the lower outer periphery of the second feature and diagonally below it, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0024] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0025] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "connected," and "linked" 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 application based on the specific circumstances.

[0026] First embodiment: Please refer to Figure 1 This embodiment provides a pile-pile vibration isolation method for isolating environmental vibrations caused by traffic loads, thereby protecting facilities sensitive to micro-vibrations, such as high-tech electronics factories and precision laboratories. It mainly includes the following steps: S1, Parameters for designing a pile-row vibration isolation system: S11. Based on the usage function and vibration environment of the high-tech electronic factory, the diameter of the vibration isolation pile 1 is determined to be 1.2 meters, the pile length is 1.5 times the Ruili wavelength (i.e., 15 meters), the number of rows is 3, and the row spacing is 1.5 times the pile diameter (i.e., 1.8 meters). S12, optimize the arrangement of vibration isolation piles 1, and design a quincunx-shaped alternating arrangement of piles to arrange the pile vibration isolation system. S13, Design the connection structure of the pile isolation system, namely, design W-shaped connection beam and straight connection beam to connect the top of the middle isolation pile 1 of the pile isolation system; S2, Preparation of foamed plastic modified concrete: First, cement, sand, stone, water, and water-reducing agent are mixed to make concrete; then, a predetermined proportion of foamed plastic particles are added and mixed at low speed to prepare foamed plastic modified concrete; wherein, the foamed plastic particles are crushed waste polystyrene foam or polyurethane foam particles with a particle size of 3mm to 10mm; the volume ratio of foamed plastic particles to concrete is 1:6 to 1:10, preferably, the volume ratio of foamed plastic particles to concrete is 1:8. S3, Construction and installation of pile vibration isolation system: S31, drilling and pile hole formation are carried out using mud slurry wall protection at the construction site to prevent soil collapse between piles; S32, Place the reinforcing cage into the pile hole; S33, foamed plastic modified concrete is injected into the corresponding pile hole in a layered pouring manner to wrap the steel cage and form vibration isolation pile 1, to prevent the foamed plastic modified concrete from floating, to ensure the uniformity and stability of the foamed plastic modified concrete, and the thickness of each layer of foamed plastic modified concrete is 20 cm, with a total height of 3 meters. S4. Conduct vibration tests and evaluate the vibration isolation effect: S41. After the construction of the pile isolation system is completed, a vibration performance test is conducted: sensors are arranged on the preset vibration source side and the protected area side of the isolation pile 1 in the pile isolation system, and a sweep frequency vibration excitation is applied to measure and calculate the vibration attenuation of the pile isolation system at different frequencies. S42. Based on the test results of the vibration attenuation of the pile isolation system at different frequencies, identify the frequency bands in the pile isolation system where the vibration isolation effect does not meet the standard. Adjust the pile spacing, pile length or pile material of the isolation pile 1 in the pile isolation system selectively to adjust the vibration isolation characteristics of the pile isolation system, and repeat the test until the attenuation effect meets the design specifications. S43 Finally, the adjusted pile isolation system was verified on-site by means of static load test, low cycle cyclic load test or setting long-term monitoring points to test the structural stability and durability of the pile isolation system under different working conditions.

[0027] Therefore, this embodiment provides a highly efficient broadband pile isolation method for environmental vibrations caused by traffic loads. It uses foamed plastic modified concrete as the core material of the isolation pile 1. The foamed plastic is composed of crushed waste polystyrene foam or polyurethane foam particles with a particle size controlled between 3mm and 10mm. The volume ratio of foamed plastic particles to concrete is 1:6 to 1:10, with a preferred ratio of 1:8. This ratio ensures that the foamed plastic modified concrete maintains sufficient structural strength while introducing a large number of closed, elastic air bubbles, significantly improving the material's damping performance. Furthermore, during preparation, cement, sand, stone, water, and water-reducing agent are first mixed using conventional methods, and then a predetermined proportion of foamed plastic particles are added and stirred at low speed to avoid excessive particle crushing.

[0028] Furthermore, between the vibration source and the protected area, single or multiple rows of piles are designed. Pile types can include circular bored piles and precast pipe piles. The spacing S between the centers of adjacent piles is controlled between 1.5 and 1.8 times the pile diameter D, i.e., S = (1.5~1.8) × D. This spacing range is the optimal range verified through extensive numerical simulations and experiments. When S < 1.5D, the piles are too dense, increasing costs, and the soil arching effect is more pronounced, which is not conducive to the dissipation of vibration energy. When S>1.8D, the gap between piles is too large, and a large amount of vibration waves will pass directly through the soil between the piles, resulting in a sharp decrease in the vibration isolation effect.

[0029] The pile diameter D is determined based on the actual vibration isolation depth requirements and geological conditions, typically ranging from 0.6m to 1.2m. The pile length should penetrate deep into the bearing layer and at least through the soft soil layer to ensure the stability of the barrier; its depth is usually 10m-25m. When vibration waves propagate to the foam-modified concrete pile, the foam particles and numerous micropores inside the pile undergo elastoplastic deformation under alternating stress, converting the mechanical energy of the vibration waves into heat energy and dissipating it, thus actively absorbing vibration energy. Simultaneously, the modified concrete has a lower density and wave velocity than traditional concrete, creating a more significant difference in wave impedance with the surrounding soil, enhancing the reflection effect of vibration waves. Furthermore, the optimized pile spacing ensures that when vibration waves encounter the pile group, most of the energy is absorbed or reflected by the piles, with only a small amount of energy diffracting through the soil between the piles. The diffracted waves are also weakened by phase differences. The optimized broadband high-efficiency vibration isolation pile 1 combines material energy absorption (for low frequencies) and structural reflection (for mid-to-high frequencies), demonstrating excellent vibration isolation effects against broadband vibrations (1Hz~100Hz) caused by traffic loads, particularly improving low-frequency vibration isolation performance that is difficult to handle with traditional methods. Moreover, this method is environmentally friendly, effectively utilizing waste foam plastics, achieving "turning waste into treasure," and meeting the requirements of sustainable development. Simultaneously, this method is economical and practical, significantly improving vibration isolation performance with only a slight increase in material costs. Its construction process is similar to traditional concrete piles, requiring no special equipment and is easy to promote. Furthermore, the vibration isolation pile 1 produced has good durability; the foam plastic particles are encapsulated in the cement matrix, preventing aging and degradation, and the system lifespan matches the building structure lifespan. This method enables the construction of a pile isolation system made of specific materials and arranged at specific intervals between the vibration source (road traffic load) and the protected building (high-tech factory). It can effectively block mid-to-high frequency vibrations and significantly attenuate low-frequency vibrations. It is also feasible to construct and is economical and durable.

[0030] Second embodiment: Please refer to Figure 2 (Refer to) Figure 3This embodiment provides a pile isolation system, constructed using the pile isolation method described in the first embodiment. It employs foamed plastic modified concrete as the core material of the isolation pile 1. The foamed plastic is composed of crushed waste polystyrene foam or polyurethane foam particles with a particle size controlled between 3mm and 10mm. The volume ratio of foamed plastic particles to concrete is 1:6 to 1:10, with a preferred ratio of 1:8. This ratio ensures that the foamed plastic modified concrete maintains sufficient structural strength while introducing a large number of closed, elastic air bubbles, significantly improving the material's damping performance. The isolation pile 1 exhibits good durability, as the foamed plastic particles are encapsulated within the cement matrix, preventing aging and degradation. The system's lifespan matches that of the building structure. This system enables the construction of a pile isolation system made of specific materials and arranged at specific intervals between the vibration source (road traffic load) and the protected building (high-tech factory). It effectively blocks mid-to-high frequency vibrations and significantly attenuates low-frequency vibrations, and is feasible, economical, and durable.

[0031] Third embodiment: A semiconductor manufacturing park mainly consists of test workshops, production workshops, a comprehensive building, a power station, warehouses, a hydrogen station, and a tank area, with a total building area of ​​approximately 169,194.26 m2. Four production workshops (B1-B4) require vibration isolation. Jiulonghu Street, a main road, runs along the north side of the park, with heavy traffic, including frequent passage of large freight vehicles. The vibrations generated by these vehicles significantly impact the factory area. The vibration isolation requirements for the first floor of workshops B1-B4 are VC-D, and for the second floor, VC-C. To isolate vibrations from road traffic, the vibration isolation system of this invention is designed and implemented.

[0032] Please refer to Figure 4 This embodiment provides a pile-pile vibration isolation method, which is applied to the aforementioned park. The method specifically includes the following steps: S1, Parameters for designing a pile isolation system: Pile type: bored cast-in-place pile; pile diameter: D=0.8 meters; pile length: L=18 meters (penetrating the shallow soft fill layer and entering the hard clay layer); pile spacing: S=1.6×D = 1.28 meters; number of rows: double rows, arranged in a quincunx pattern; Pile material: Foamed plastic modified concrete, using waste EPS (polystyrene) foam particles with a particle size of about 5mm, with a volume ratio of 1:8 to C30 concrete; S2, Construction pile vibration isolation system: On-site positioning and layout, determining pile positions according to design spacing; Use a rotary drilling rig to drill and clean the hole; Prepare foamed plastic modified concrete at the on-site mixing plant: first mix C30 concrete, then add EPS particles under low-speed mixing to ensure uniform mixing; Pour the concrete for the pile body and vibrate it to ensure it is compacted; Maintain until designed strength; S3, Verification of the effectiveness of the pile vibration isolation system: Please refer to Figure 4 After the pile vibration isolation system was completed, micro-vibration tests were conducted inside the factory building. The measured data showed that, when heavy trucks passed by, the pile vibration isolation system constructed using the method described in this embodiment reduced the average effective value of vibration velocity by 58.2% and the maximum effective value by 63.9% in the critical 1-200Hz frequency band compared to traditional concrete pile designs. The vibration values ​​on the first floor of the factory building were successfully controlled within the VC-C level, and the vibration values ​​on the second floor were successfully controlled within the VC-D level, fully meeting the operational requirements of the production equipment.

[0033] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for vibration isolation using pile banks, characterized in that, Includes the following steps: S1 represents the parameters for designing a pile isolation system; S2, Preparation of foamed plastic modified concrete; S3, Construction and installation of the pile vibration isolation system; S4, Conduct vibration tests on the pile isolation system and evaluate the vibration isolation effect.

2. The pile isolation method according to claim 1, characterized in that, Step S1 specifically includes the following steps: Based on the usage function and vibration environment of the construction area, determine the pile diameter, pile length, number of rows, and spacing of the piles in the pile isolation system. The design incorporates alternating plum blossom-shaped pile arrangements to form the pile vibration isolation system. Design W-shaped connecting beams and straight connecting beams to connect the tops of the vibration isolation piles in the pile isolation system.

3. The pile isolation method according to claim 2, characterized in that, In the aforementioned pile isolation system, the isolation piles are arranged in parallel at intervals, and the pile type includes circular bored piles or precast pipe piles; the pile diameter of the isolation pile is 0.6-1.2m, the pile length is 10-25m, and the center distance between adjacent isolation piles is 1.5-1.8 times the diameter of a single pile; the total number of rows of isolation piles is 3-7, and the length L of a single pile satisfies: λ R ≤L≤1.5λ R , where λ R The wavelength of Rayleigh is calculated using the formula λ. R =V s / f,V s denoted as the average shear wave velocity of the soil layer at the site, and f is the frequency of the main vibration source that needs to be isolated.

4. The pile isolation method according to claim 1, characterized in that, Step S2 specifically includes the following steps: First, cement, sand, stone, water, and water-reducing agent are mixed to make concrete; then, a predetermined proportion of foamed plastic particles are added and mixed evenly at low speed to prepare foamed plastic modified concrete.

5. The pile isolation method according to claim 4, characterized in that, The foamed plastic particles are crushed waste polystyrene foam or polyurethane foam particles with a particle size of 3mm to 10mm.

6. The pile isolation method according to claim 4, characterized in that, The volume ratio of the foamed plastic particles to the concrete is 1:6 to 1:

10.

7. The pile isolation method according to claim 6, characterized in that, The volume ratio of the foamed plastic particles to the concrete is 1:

8.

8. The pile isolation method according to claim 1, characterized in that, Step S3 specifically includes the following steps: At the construction site, mud slurry was used to protect the wall during drilling and to form pile holes; The reinforcing cage is placed inside the pile hole; The foamed plastic modified concrete is injected into the corresponding pile holes in layers to wrap the steel cage and form vibration isolation piles. Repeat the above steps until the construction of the pile vibration isolation system is completed.

9. The pile isolation method according to claim 1, characterized in that, Step S4 specifically includes the following steps: After the construction of the pile isolation system is completed, vibration performance test is carried out: sensors are arranged on the preset vibration source side and the protected area side of the isolation piles in the pile isolation system, and sweep frequency vibration excitation is applied to measure and calculate the vibration attenuation of the pile isolation system at different frequencies. Based on the test results of the vibration attenuation of the pile isolation system at different frequencies, the frequency bands in which the vibration isolation effect of the pile isolation system does not meet the standard are identified. The vibration isolation characteristics of the pile isolation system are adjusted by selectively adjusting the pile spacing, pile length or pile material of the isolation piles in the pile isolation system, and repeated tests are conducted until the attenuation effect meets the design specifications. The adjusted pile vibration isolation system was verified on-site by means of static load test, low-cycle cyclic load test or setting long-term monitoring points to test the structural stability and durability of the pile vibration isolation system under different working conditions.

10. A pile vibration isolation system, characterized in that, It is constructed using the pile isolation method described in any one of claims 1 to 9.

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