Grating vibration isolation foundation micro-vibration control construction technology

Abstract

The invention discloses a micro-vibration control construction process for a grating vibration isolation foundation, and relates to the technical field of building construction. Comprising the following steps: S1, measuring and positioning: measuring and releasing sideline control piles of each shock insulation pier and a sand-gravel cushion layer; s2, construction of a graded gravel cushion layer; s3, compaction coefficient detection; s4, paying-off is conducted on the bottoms of the shock insulation piers, wherein the sideline control point of each shock insulation pier is measured and paid off; s5, side formwork installation and steel bar binding, wherein the distance between the vibration isolation pier and the equipment walkway foundation is 10 cm, a foam polyethylene plate with the thickness of 10 cm is adopted as the side formwork, and the side formwork and the steel bars are installed, bound and formed together; s6, mass concrete pouring and temperature control, wherein layered pushing type continuous pouring is adopted, and the thickness of each layer does not exceed 50 cm; s7, concrete curing; and S8, buffer seam treatment. The compaction graded gravel cushion layer is arranged as a vibration isolation filtering layer, and the large-scale independent vibration isolation pier body is combined, so that double isolation of earthquake dynamic response and environmental vibration is effectively realized, and stable operation of a precise instrument is ensured.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, specifically to a construction process for micro-vibration control of grating-isolated foundations. Background Technology

[0002] With the increasingly stringent requirements for vibration control in high-end industries such as precision instrument manufacturing, semiconductors, and biomedicine, traditional building structures can no longer meet their micro-vibration standards. Especially in high-intensity seismic fortification areas (such as 8 degrees 0.20g), how to isolate seismic energy and effectively suppress daily micro-vibrations has become a core challenge in the design of underground production workshops.

[0003] Therefore, it is necessary to provide a construction process for micro-vibration control of seismic vibration isolation foundations using optical gratings. Summary of the Invention

[0004] The main objective of this invention is to provide a construction process for micro-vibration control of grating vibration isolation foundations, in order to solve the problems existing in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A construction process for micro-vibration control of grating-isolated foundations includes the following steps: S1. Measurement and Positioning: Based on the building's positioning points and building plan, accurately measure and mark the control stakes for the edge lines of each seismic isolation pier and the gravel cushion layer to ensure accurate positioning of multiple piers; S2. Construction of graded sand and gravel cushion layer: Natural graded sand and gravel are used, and the layers are laid in strict layers. The loose thickness of each layer is no more than 20cm, and the compacted thickness is ≤15cm. S3. Compaction Coefficient Test: After the graded sand and gravel cushion layer is constructed, the compaction degree is tested on-site using the sand filling method. If it is not qualified, it is immediately compacted. S4. Laying out the bottom line of the seismic isolation pier: According to the design requirements of the seismic isolation pier, accurately measure and lay out the edge control points of each seismic isolation pier to ensure that the position of the seismic isolation pier reinforcement is consistent with the design. S5. Side formwork installation and rebar binding: The specifications, spacing and protective layer thickness of the rebar shall be strictly constructed in accordance with the drawings. The distance between the vibration isolation pier and the equipment walkway foundation shall be 10cm. A 10cm thick foamed polyethylene board shall be used as the side formwork and installed and bound together with the rebar. S6. Large-volume concrete pouring and temperature control: adopt layered continuous pouring, control the thickness of each layer to not exceed 50cm; pre-embed cooling water pipes, circulate water for cooling; embed temperature measuring elements to monitor the temperature difference between the core and the surface in real time, and control it within 25℃ to prevent temperature cracks. S7. Concrete curing: Immediately after pouring, cover with plastic film to retain water, and cover with geotextile on top to keep warm and moist. The curing time shall not be less than 14 days. S8. Buffer joint treatment: A buffer joint is set between the seismic isolation pier and the walkway foundation. After removing the 10cm thick foam polyethylene board, clean the debris in the buffer joint. The buffer joint is sealed with glass wool wrapped with 24# galvanized steel plate.

[0006] Furthermore, before proceeding with step S1, construction preparations are carried out, including the preparation of a special construction plan, a large-volume concrete construction operation guide, and technical instructions, which are then distributed to the work teams.

[0007] Furthermore, in step S2, manual labor is used in conjunction with a frog-type rammer to compact the sand and gravel, avoiding excessive vibration that could cause the sand and gravel to break.

[0008] Furthermore, in step S6, low-heat cement is used, high-efficiency water-reducing agent and appropriate amount of fly ash are added, the mix ratio is adjusted, and the slump is controlled.

[0009] Furthermore, in step S8, the 24# galvanized steel sheet is bonded to the base layer using PVC waterproof membrane.

[0010] Furthermore, in step S8, a stainless steel plate support is provided at the upper end of the 24# galvanized steel plate, and the end of the stainless steel plate support is connected to the finished floor surface by silicone sealant.

[0011] Furthermore, in step S3, the compaction coefficient is ≥0.97.

[0012] Compared with the prior art, the present invention has the following beneficial effects: 1. Dual seismic isolation performance: It utilizes the damping characteristics of the graded sand and gravel cushion layer to filter high-frequency micro-vibrations, and resists low-frequency seismic disturbances through the huge mass and inertia of the seismic isolation pier, thus achieving full-frequency vibration control.

[0013] 2. Refined design: Design based on site characteristic period (0.55s) to avoid resonance effect, and set buffer joint between seismic isolation piers and walkway foundation to prevent stress transfer.

[0014] 3. Strong quality controllability: The compaction coefficient of graded sand and gravel (≥0.97) is used as a key control indicator. The uniformity and stability of the vibration isolation layer are ensured through a strict layered rolling process.

[0015] 4. Good structural integrity: The construction of the seismic isolation pier with large-volume concrete effectively prevents cracks and ensures the integrity of the pier body through measures such as optimized mix proportions and temperature control.

[0016] 5. Large-scale and efficient construction: Multiple seismic isolation piers adopt a standardized formwork system and assembly line operation, which greatly improves construction efficiency and ensures accuracy. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the building plan of a micro-vibration control construction process for a grating vibration isolation foundation according to the present invention.

[0018] Figure 2 This is a schematic diagram of the reinforcement of the vibration isolation pier in the construction process of micro-vibration control for grating vibration isolation foundation according to the present invention.

[0019] Figure 3 This is a schematic diagram of the graded sand and gravel cushion layer in the micro-vibration control construction process of a grating vibration isolation foundation according to the present invention.

[0020] Figure 4 This is a schematic diagram of the buffer joint treatment in a micro-vibration control construction process for a grating vibration isolation foundation according to the present invention.

[0021] Among them, 1-vibration isolation block; 2-graded sand and gravel cushion layer; 3-buffer joint; 4-24# galvanized steel plate; 5-glass wool; 6-PVC waterproof membrane; 7-stainless steel plate support; 8-silicone; 9-finished floor surface. Detailed Implementation

[0022] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] Example 1

[0024] Combination Figures 1-4 This invention provides a micro-vibration control construction process for grating vibration isolation foundations, applicable to areas with seismic fortification intensity of 8 degrees and below, and for special buildings with strict vibration requirements such as: ① underground precision instrument manufacturing workshops and testing laboratories; ② semiconductor chip manufacturing plants (FAB); ③ biomedical cleanrooms; ④ data centers, astronomical observatories, and other special buildings with micro-vibration control requirements.

[0025] The process flow is as follows: construction preparation → measurement and positioning → construction of graded sand and gravel cushion layer → compaction coefficient test → layout of the bottom of the seismic isolation pier → side formwork installation and rebar binding → large volume concrete pouring and temperature control → concrete curing → buffer joint treatment.

[0026] Specifically, the following steps are included: Before proceeding with step S1, construction preparations are carried out, including the preparation of a specific construction plan, a large-volume concrete construction operation manual, and technical briefings, which are then distributed to the work teams. Technical guidance is provided to on-site construction personnel, and the technical and quality standards of incoming materials are reviewed. Relevant certificates for special operations personnel are checked to ensure that personnel are properly certified and licensed to perform their duties.

[0027] S1. Measurement and Positioning: Based on the building positioning points provided by the surveying department and the approved building plan, use a total station to accurately measure and set out the control stakes of each seismic isolation pier and the sand and gravel cushion layer to ensure accurate positioning of multiple piers. In this embodiment, a total of 44 seismic isolation piers are designed, and the size of the seismic isolation piers is 9.8m×9.8m×2.5m.

[0028] S2. Construction of graded sand and gravel cushion layer: Natural graded sand and gravel are used, and the particle size, mud content and other indicators must meet the design requirements; manual and frog-type rammer are used for compaction to avoid over-vibration that could cause the sand and gravel to break; strict layer laying is required, with each layer having a loose thickness of no more than 20cm and a compacted thickness of ≤15cm.

[0029] S3. Compaction Coefficient Test: After the graded sand and gravel cushion layer is constructed, the compaction degree is tested on-site using the sand filling method. The compaction coefficient must be ≥0.97. If it is not qualified, it must be compacted immediately.

[0030] S4. Laying out the bottom line of the seismic isolation pier: According to the requirements of the seismic isolation pier in the design documents, use a total station to accurately measure and lay out the edge control points of each seismic isolation pier to ensure that the position of the seismic isolation pier reinforcement is consistent with the design documents.

[0031] S5. Side formwork installation and rebar binding: The specifications, spacing and protective layer thickness of the rebar shall be strictly constructed in accordance with the drawings. The distance between the vibration isolation pier and the equipment walkway foundation shall be 10cm. 10cm thick foam polyethylene board shall be used as the side formwork and installed and bound together with the rebar.

[0032] Due to the large size of the pier and the fact that there is only a 10cm gap between it and the foundation of the equipment walkway, it is more convenient to use 10cm thick foam polyethylene board as a template and install it together with the steel bars to facilitate construction.

[0033] S6. Large-volume concrete pouring and temperature control: Low-heat cement is used, with high-efficiency water-reducing agent and appropriate amount of fly ash added, and the mix proportion is optimized and adjusted to control the slump; layered continuous pouring is adopted, and the thickness of each layer is controlled to not exceed 50cm; cooling water pipes are pre-embedded for water circulation and cooling; temperature measuring elements are embedded to monitor the temperature difference between the core and the surface in real time and control it within 25℃ to prevent temperature cracks. S7. Concrete curing: Immediately after pouring, cover with plastic film to retain water, and cover with geotextile on top to keep warm and moist. The curing time shall not be less than 14 days. S8. Buffer Joint Treatment: A buffer joint 3 is installed between the seismic isolation pier and the walkway foundation. After removing the 10cm thick foam polyethylene board, the debris in the buffer joint is cleaned. The buffer joint 3 is then sealed with glass wool 5 wrapped with 24# galvanized steel plate 4.

[0034] In step S8, the 24# galvanized steel plate 4 is bonded to the base layer by PVC waterproof membrane 6; a stainless steel plate support 7 is provided on the upper end of the 24# galvanized steel plate 4, and the end of the stainless steel plate support 7 is sealed and connected to the finished floor surface 9 by silicone 8.

[0035] The core principles of this seismic resistance technology are "impedance mismatch" and "mass block effect".

[0036] Vibration wave filtering: A 30cm thick graded sand and gravel cushion layer is set between the seismic isolation pier and the main raft foundation. The material of this layer has a huge difference in wave impedance from concrete. When vibration waves are transmitted from the raft foundation to this loose medium layer, scattering, reflection and energy attenuation will occur, which is like a "low frequency filter" to effectively isolate high frequency vibrations from the foundation and the environment.

[0037] Inertial stability: The large reinforced concrete seismic isolation pier, measuring 9.8m × 9.8m × 2.5m, constitutes a huge inertial mass block. According to Newton's second law (F=ma), under the action of seismic acceleration (0.20g), its huge mass (m) makes its tendency to maintain inertial stability much greater than its tendency to accelerate, thereby greatly reducing the vibration response of the instruments and equipment on top of it.

[0038] Buffer isolation: The seismic isolation pier maintains a 10cm gap with the foundation of the surrounding equipment walkway, and is filled with flexible materials, such as foam polyethylene board + silicone sealant. This physical barrier completely cuts off the path of vibration transmission through the structure, ensuring the independence of the seismic isolation system.

[0039] The equipment and materials required for the implementation of the process are as follows: Materials: graded sand and gravel, C30 concrete, HRB400 steel bars, cooling water pipes, temperature measuring elements, formwork system, and flexible filling material.

[0040] Equipment: Total station, frog-type tamping machine, sand filling tester density testing equipment, concrete mixing plant, pump truck, immersion vibrator, automatic temperature monitoring system.

[0041] The process quality control requirements are as follows: Key control items: Compaction coefficient of graded sand and gravel cushion layer ≥ 0.97 (no less than 3 points tested per 100㎡). Deviation of seismic isolation pier plane position ≤ 10mm, top surface elevation deviation ≤ ±5mm. Temperature of large volume concrete upon placement ≤ 28℃, internal and external temperature difference ≤ 25℃, and through cracks are strictly prohibited.

[0042] General items: Allowable deviations in steel reinforcement installation, formwork installation, and concrete appearance quality must meet the requirements of the "Code for Acceptance of Construction Quality of Concrete Structures" (GB50204).

[0043] The process of this invention is applicable to projects in the Precision Manufacturing Industrial Park of Horinger New Area, Inner Mongolia.

[0044] The process of this invention provides vibration isolation effects far exceeding those of conventional methods, creating an "ultra-quiet" environment for high-end manufacturing.

[0045] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A construction process for micro-vibration control of grating-isolated foundations, characterized in that, The following steps are included: S1. Measurement and Positioning: Based on the building's positioning points and building plan, accurately measure and mark the control stakes for the edge lines of each seismic isolation pier and the gravel cushion layer to ensure accurate positioning of multiple piers; S2. Construction of graded sand and gravel cushion layer: Natural graded sand and gravel are used, and the layers are laid in strict layers. The loose thickness of each layer is no more than 20cm, and the compacted thickness is ≤15cm. S3. Compaction Coefficient Test: After the graded sand and gravel cushion layer is constructed, the compaction degree is tested on-site using the sand filling method. If it is not qualified, it is immediately compacted. S4. Laying out the bottom line of the seismic isolation pier: According to the design requirements of the seismic isolation pier, accurately measure and lay out the edge control points of each seismic isolation pier to ensure that the position of the seismic isolation pier reinforcement is consistent with the design. S5. Side formwork installation and rebar binding: The specifications, spacing and protective layer thickness of the rebar shall be strictly constructed in accordance with the drawings. The distance between the vibration isolation pier and the equipment walkway foundation shall be 10cm. A 10cm thick foamed polyethylene board shall be used as the side formwork and installed and bound together with the rebar. S6. Large-volume concrete pouring and temperature control: adopt layered continuous pouring, control the thickness of each layer to not exceed 50cm; pre-embed cooling water pipes, circulate water for cooling; embed temperature measuring elements to monitor the temperature difference between the core and the surface in real time, and control it within 25℃ to prevent temperature cracks. S7. Concrete curing: Immediately after pouring, cover with plastic film to retain water, and cover with geotextile on top to keep warm and moist. S8. Buffer joint treatment: A buffer joint is set between the seismic isolation pier and the walkway foundation. After removing the 10cm thick foam polyethylene board, clean the debris in the buffer joint. The buffer joint is sealed with glass wool wrapped with 24# galvanized steel plate.

2. The micro-vibration control construction process for grating vibration isolation foundations as described in claim 1, characterized in that, Before proceeding with step S1, construction preparations are carried out, including the preparation of a special construction plan, a large-volume concrete construction operation guide, and technical instructions, which are then distributed to the work teams.

3. The micro-vibration control construction process for a grating vibration isolation foundation as described in claim 1, characterized in that, In step S2, manual labor is used in conjunction with a frog-type rammer to compact the sand and gravel, avoiding excessive vibration that could cause the sand and gravel to break.

4. The construction process for micro-vibration control of grating vibration isolation foundation as described in claim 1, characterized in that, In step S6, low-heat cement is used, high-efficiency water-reducing agent and appropriate amount of fly ash are added, the mix ratio is adjusted, and the slump is controlled.

5. The construction process for micro-vibration control of grating-isolated foundations as described in claim 1, characterized in that, In step S8, the 24# galvanized steel sheet is bonded to the base layer using PVC waterproof membrane.

6. The construction process for micro-vibration control of grating-isolated foundations as described in claim 1, characterized in that, In step S8, a stainless steel plate support is provided at the upper end of the 24# galvanized steel plate, and the end of the stainless steel plate support is connected to the finished floor surface by silicone sealant.

7. The construction process for micro-vibration control of grating vibration isolation foundation as described in claim 1, characterized in that, In step S3, the compaction coefficient is ≥0.97.

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