A construction method for grouting and compacting a large-surface column base plate

Abstract

A method for dense grouting and molding under large-face column base plates includes the following steps: S1, roughening the top surface of the short concrete column to expose fresh aggregate; S2, setting up formwork around the column base plate and attaching sealing strips to the inside of the formwork; S3, controlling the particle size of the grout to be no greater than 5mm, and mixing with water according to the mix ratio; S4, using a low-position pouring method, continuously pouring grout from one end of the column base plate in a unidirectional direction, allowing the grout to advance from one end to the opposite diagonal end; S5, after grouting, smoothing the surface for 30-60 minutes, removing excess grout and repairing defects; S6, after demolding, testing the density of the grout layer. This application effectively solves the technical problems of easy hollowing and air entrapment in grouting of large-face column base plates, while avoiding segregation and bleeding caused by traditional vibration, ensuring the uniformity and strength consistency of the grout; the construction method does not require large equipment, is simple to operate, and has high safety, and is especially suitable for high-rise, large-span, and heavy-load steel structure projects.

Description

Technical Field

[0001] This application belongs to the field of steel structure construction technology in building engineering, and in particular relates to a method for grouting and compacting construction under large column base plates. Background Technology

[0002] In steel structure engineering, a dense bearing layer needs to be formed between the steel column base plate and the concrete foundation through secondary grouting to ensure uniform load transfer and improve the overall structural integrity and seismic performance. Current conventional column base grouting processes are mostly suitable for small-area column base plates. For large-area column base plates with a side length ≥800mm, the following prominent problems exist: the grouting area is large and the path is long; the flow resistance of fine aggregate concrete or grout material is high, easily leading to insufficient density problems such as central hollow areas, edge grout gaps, and internal air entrapment; traditional single-sided grouting and natural gravity flow methods are difficult to control the grout direction, easily forming closed air chambers that cannot be eliminated by conventional vibration; the space under the column base plate is narrow, making it impossible for conventional vibration equipment to reach, easily causing segregation, bleeding, and uneven strength; the lack of process control and testing methods for density makes it prone to settlement, voids, and uneven stress in the later stages, endangering structural safety. Existing technologies have not formed a systematic dense forming method for large-area column base plates (≥800mm), making it difficult to meet the quality requirements of high-rise, large-span, and heavy-load steel structure projects. Summary of the Invention

[0003] This application provides a method for grouting and compacting under large column base plates, aiming to solve the technical problems of easy hollowing and air entrapment, insufficient compaction, and uncontrollable quality in grouting under large column base plates.

[0004] To solve at least one of the above-mentioned technical problems, the technical solution adopted in this application is:

[0005] A method for grouting and compacting a large column base plate includes the following steps:

[0006] S1. Roughen the top surface of the short concrete foundation column to expose fresh aggregate, remove slag and dust, and wash it clean with a high-pressure water gun; moisten the base surface 24 hours in advance, and remove standing water 1 hour before grouting to ensure the base surface is moist inside and dry outside; check the elevation, levelness, and anchor bolt position of the column base plate, and make minor adjustments to areas with uneven gaps to control the grout layer thickness to 30mm-100mm; use an endoscope to inspect the hidden area under the column base plate to ensure there are no debris or standing water.

[0007] S2. Set up formwork around the column base plate, attach sealing strips to the inside of the formwork, seal the bottom of the formwork tightly where it contacts the top of the short column in the concrete foundation, and make the formwork height at least 50mm higher than the top surface of the column base plate.

[0008] S3. Control the particle size of the grouting material to be no greater than 5mm, add water and mix according to the ratio, control the slump to be 300±20mm, the initial setting time to be ≥120min, and let it stand for 2min-3min after mixing to defoam.

[0009] S4. Using a low-position pouring method, the grout is continuously poured in one direction starting from one end of the column base plate, so that the grout is pushed from one end to the opposite end in sequence. During the grouting process, an auxiliary vibration device is used for vibration. When the grout flows out from the other end of the column base plate and is full and free of air bubbles, the grouting is completed.

[0010] S5. After grouting, surface finishing is carried out 30-60 minutes after grouting, excess grout is removed and defects are repaired. After final setting, cover with moisturizing material for curing. The curing temperature is not lower than 5℃ and the curing time is not less than 7 days. Disturbance, stepping and impact are prohibited within 24 hours. Subsequent processes can only be carried out after the strength reaches 70% of the design strength.

[0011] S6. After demolding, the density of the grouting layer is tested. If hollow or weak areas are found, drilling and grouting are used for treatment.

[0012] Furthermore, in S1, after the roughening treatment exposes fresh aggregate on the base surface, slag and dust are removed, and the surface is washed clean with a high-pressure water gun. The base surface is moistened 24 hours in advance, and standing water is removed 1 hour before grouting to achieve an internally moist and externally dry state.

[0013] Furthermore, in S2, the template is a wooden template or a steel template, the sealing strip pasted on the inside of the template is a double-sided sealing strip, and the bottom of the template and the contact surface with the foundation are sealed tightly with sealing material to prevent grout leakage and air intake.

[0014] Furthermore, in S3, the grouting material is fine stone concrete or high-strength non-shrink grouting material, the particle size of the grouting material is not greater than 5mm, the slump is 300±20mm, the initial setting time is ≥120min, and it can be poured after standing for 2min-3min to defoam after stirring.

[0015] Furthermore, in S4, the low-position pouring method involves pouring from the bottom position on one side of the column base plate, maintaining continuous pouring during the grouting process, and prohibiting simultaneous pouring at multiple points.

[0016] Furthermore, the vibration auxiliary device includes a hand drill, an adapter, and a custom spring. The hand drill is connected to the custom spring via the adapter, and the custom spring extends into the narrow space under the column base plate to perform vibration. The vibration operation is carried out synchronously with the grouting process, and the custom spring reciprocates under the column base plate to expel air bubbles in the grout and promote the flow and compaction of the grout.

[0017] Furthermore, in S5, the moisturizing materials are geotextile and plastic film. After final setting, the geotextile is immediately covered and then covered with plastic film for moisturizing and curing.

[0018] In low-temperature environments, extend the curing time and take insulation measures; in high-temperature or windy weather, set up sunshade and windproof sheds.

[0019] After surface finishing, remove excess slurry and repair surface defects. Keep the covering moist during curing to prevent surface cracking.

[0020] Furthermore, in S6, the density test is performed by a combination of the impact method and the ultrasonic test; the drilling grouting treatment is as follows: drill holes of Φ8mm-Φ10mm, inject grout of the same proportion using a low-pressure method, and then perform pressure sealing after grouting.

[0021] Furthermore, in S5, test blocks under the same conditions are made simultaneously during the grouting construction process to test the 3-day and 28-day strengths, ensuring that the design requirements are met.

[0022] Furthermore, the large-face column base plate is a column base plate with a side length ≥ 800mm.

[0023] This application presents a method for grouting and compacting large-area column base plates. By optimizing the unidirectional continuous grouting sequence and using an auxiliary vibration device consisting of a hand drill, adapter, and custom springs, the grout flows directionally under the large-area column base plates, allowing for thorough air release. This achieves uniform compaction without voids throughout the entire area, with a compaction qualification rate consistently exceeding 98%. The custom springs can extend into the narrow space under the column base plates for simultaneous grouting and vibration, avoiding the construction difficulties caused by conventional vibration equipment not being able to reach the area and effectively preventing segregation and bleeding, ensuring the uniformity and consistency of grout strength. The accompanying hammering method combined with an ultrasonic testing system and a low-pressure grouting repair process ensures that the grouting quality is controllable throughout the entire process, significantly reducing the risk of later settlement and voids, and significantly improving structural safety and durability. Furthermore, the construction does not require large equipment and is simple and efficient to operate, making it particularly suitable for high-rise, large-span, and heavy-load steel structure projects. Attached Figure Description

[0024] Figure 1 This is a three-dimensional view of the grouting and compaction construction of the large column base plate in this application;

[0025] Figure 2 This is a top view of the grouting and compaction construction of the large column base plate in this application;

[0026] Figure 3 This is a schematic diagram of the structure of the vibration auxiliary device in this application.

[0027] In the diagram: 1. Box column; 2. Large column base plate; 3. Double-sided strip; 4. Formwork; 5. Anchor bolt; 6. Short column of concrete foundation; 7. Hand drill; 8. Adapter joint; 9. Spring. Detailed Implementation

[0028] The present application will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0029] This embodiment proposes a method for grouting and compacting a large-face column base plate, such as... Figures 1 to 3 As shown, this method is mainly applicable to secondary grouting construction of fine aggregate concrete or high-strength non-shrink grout with a column base plate side length ≥ 800mm. The structure to be constructed mainly includes a box column 1, a large column base plate 2 fixedly connected to the bottom of the box column 1, and a short concrete foundation column 6 set below the large column base plate 2. The large column base plate 2 is anchored to the short concrete foundation column 6 by anchor bolts 5.

[0030] S1. Roughen the top surface of the short concrete foundation column to expose fresh aggregate, remove slag and dust, and wash it clean with a high-pressure water gun; moisten the base surface 24 hours in advance, and remove standing water 1 hour before grouting to make the base surface wet inside and dry outside; check the elevation, levelness and anchor bolt position of the column base plate, make fine adjustments to uneven gaps, and control the grout layer thickness to 30mm-100mm; use an endoscope to check the hidden area under the column base plate to ensure that there are no debris and no water accumulation.

[0031] Specifically, such as Figure 1 As shown, the structure to be constructed mainly includes box-type columns 1, large-face column base plates 2 fixedly connected to the bottom of box-type columns 1, and short concrete foundation columns 6 set below the large-face column base plates 2. First, the top surface of the short concrete foundation columns 6 is roughened to expose fresh aggregate to increase the adhesion between the grouting layer and the foundation interface. After roughening, the slag and dust on the top surface are removed, and the top surface is washed clean with a high-pressure water gun to ensure that the base surface is free of loose particles and oil stains. To ensure the base surface is in a suitable moist state, it is moistened with water 24 hours in advance to allow the moisture to fully penetrate; 1 hour before the formal grouting, the surface is cleaned of standing water with a sponge or compressed air, so that the base surface is moist inside but dry on the outside, i.e., saturated inside but without standing water on the surface. This avoids excessive grout absorption by the base surface leading to water loss of the grout and also prevents standing water from mixing into the grout and affecting its strength.

[0032] like Figure 2As shown in the top view, the large column base plate 2 is anchored to the short concrete foundation column 6 via anchor bolts 5. The elevation and levelness of the large column base plate 2, as well as the pre-embedded positions of the anchor bolts 5, are then checked. Minor adjustments are made to areas with uneven gaps between the column base plate and the foundation to ensure the subsequent grout layer thickness is controlled within the range of 30mm-100mm. If the grout layer is too thin, the bearing capacity will be insufficient; if it is too thick, it is prone to shrinkage and cracking. A thickness range of 30mm-100mm ensures both load-bearing capacity and effective control of shrinkage deformation. To ensure that there are no debris or standing water in the concealed area below the column base plate 2, an endoscope is used to inspect each area. Only after confirming the absence of visible debris and standing water can the next step be carried out. These surface treatment measures effectively improve the bond strength between the grout layer and the concrete foundation, avoiding problems such as voids and insufficient strength caused by interface contamination or the presence of standing water.

[0033] S2. Set up formwork around the column base plate, attach sealing strips to the inside of the formwork, seal the bottom of the formwork tightly where it contacts the top of the short column in the concrete foundation, and make sure the height of the formwork is more than 50mm higher than the top surface of the column base plate.

[0034] Specifically, after the base surface treatment is completed, formwork is erected. Specifically, formwork 4 is erected around the perimeter of the large column base plate 2. Formwork 4 can be made of wood or steel. Double-sided sealing strips 3 (i.e., double-sided sealing strips) are pasted on the inner side of formwork 4. The contact point between the bottom of formwork 4 and the top surface of the short concrete column 6 is sealed tightly with sealing material. The main function of the formwork seal is to prevent grout from leaking out from the gaps at the bottom of the formwork during grouting, and to prevent outside air from entering the grout layer from the bottom and forming pores. The erection height of formwork 4 should be at least 50mm higher than the upper surface of the large column base plate 2. This height is required to provide sufficient static pressure head for the grout, promoting its full flow below the column base plate; it also provides operational space for surface finishing, ensuring finishing quality.

[0035] S3. Control the particle size of the grouting material to be no greater than 5mm, add water and mix according to the ratio, control the slump to be 300±20mm, the initial setting time to be ≥120min, and let it stand for 2min-3min after mixing to defoam.

[0036] Specifically, when preparing the grout, fine aggregate concrete or high-strength non-shrink grout is used, and the aggregate particle size in the grout is controlled below 5mm. Grout with a fine aggregate gradation is sampled because it has good fluidity, is not prone to sedimentation, and can flow smoothly under large-area, long-path column bases, avoiding flow blockage and uneven compaction caused by coarse aggregate accumulation. Each component material is weighed strictly according to the design ratio, and water is added and stirred for 3-5 minutes until the grout has a uniform color and no dry powder lumps. During stirring, the slump of the grout is controlled at 300±20mm. This slump range ensures that the grout has good fluidity to fill the entire area under the column base, while not being too thin to cause segregation and bleeding.

[0037] The initial setting time should be controlled at over 120 minutes to ensure that the grout remains flowable throughout the entire construction window from mixing to grouting completion, avoiding grouting interruptions or cold joints due to excessively rapid initial setting. After mixing, allow the grout to stand for 2-3 minutes to allow natural defoaming, enabling large air bubbles entrained during mixing to rise and burst naturally, reducing the air bubble content inside the grout and minimizing the risk of voids and air entrapment from the source.

[0038] S4. Using a low-position pouring method, grout is continuously poured in one direction starting from one end of the column base plate, so that the grout is pushed from one end to the opposite end in sequence; during the grouting process, an auxiliary vibration device is used for vibration. When the grout flows out from the other end of the column base plate and is full and free of air bubbles, the grouting is completed.

[0039] Specifically, the grouting operation adopts a low-position pouring method, starting from one end of the large column base plate 2 and continuously pouring grout in one direction. Low-position pouring means pouring from the bottom of one side of the column base plate, allowing the grout to advance horizontally along the bottom surface of the column base plate under its own gravity from the inlet side towards the diagonal end, gradually filling the entire space under the column base plate. During the grouting process, continuous pouring must be maintained. Simultaneous pouring at multiple points on the large column base plate 2 is prohibited. Simultaneous pouring at multiple points will cause the grout flow fronts to converge, easily trapping air and forming closed air chambers. These air chambers are surrounded by already filled grout and cannot be reached by auxiliary vibration devices. Once formed, they cannot be eliminated by subsequent vibration. The correct pouring method is to start the grout from the initial end and steadily advance it in one direction towards the diagonal end, forming a single, orderly flow front. This ensures that all air under the column base plate is expelled as the grout advances layer by layer, avoiding the formation of closed air chambers.

[0040] During the grouting process, an auxiliary vibration device is used simultaneously for compaction. For example... Figure 3As shown, the auxiliary vibratory device consists of a hand drill 7, an adapter 8, and a custom spring 9. The hand drill 7 serves as the power source, providing rotational driving force. The output end of the hand drill 7 is fixedly connected to one end of the custom spring 9 via the adapter 8. The adapter 8 enables the power transmission between the rotational motion of the hand drill 7 and the custom spring 9, while ensuring a secure and reliable connection. The custom spring 9 is a helical spring with a certain stiffness and elasticity. Its outer diameter is smaller than the clearance dimension of the narrow space under the column base plate 2, allowing it to freely extend into the bottom of the column base plate 2 for operation. After the hand drill 7 is started, the rotational power is transmitted to the custom spring 9 via the adapter 8. The custom spring 9 rotates and reciprocates at high speed under the column base plate 2, continuously agitating the slurry.

[0041] The spiral structure of the custom spring 9 generates multi-dimensional radial and axial disturbance forces during high-speed rotation: on the one hand, the disturbance breaks up and expels air bubbles trapped in the grout, causing them to rise to the grout surface and escape; on the other hand, the disturbance promotes the flow of grout to all corners of the column base plate 2, overcoming large-area flow resistance and ensuring that the central and corner areas are fully filled with grout. Due to the flexibility of the custom spring 9, the vibration position and angle can be flexibly adjusted without damaging the bottom of the column base plate 2, adapting to various irregular or confined spaces.

[0042] Vibration is performed synchronously with the grouting process; that is, vibration follows the grout as it is poured, achieving simultaneous grouting and vibration. This synchronous operation ensures that the grout remains undisturbed during its flow, preventing segregation or bleeding due to stagnation. Continuously observe the diagonal end of the column base plate 2 (i.e., the side opposite the grouting end). When the grout flows smoothly from the diagonal end of the column base plate 2, and appears completely full without any air bubbles, it indicates that the space below the column base plate 2 has been completely filled with grout, and the grouting operation is complete.

[0043] S5. After grouting, perform surface finishing 30-60 minutes, remove excess grout and repair defects; after final setting, cover with moisturizing material for curing, with a curing temperature of not less than 5℃ and a curing time of not less than 7 days; do not disturb, step on or impact within 24 hours, and subsequent procedures can only be carried out after the strength reaches 70% of the design strength.

[0044] Specifically, surface finishing should be performed 30-60 minutes after grouting. At this time, the grout has initially lost its fluidity but has not yet fully set, making it the optimal time for surface finishing. Use a trowel to smooth and polish the surface, remove excess grout around the column base plate, and repair any minor dents or air bubbles on the surface. Timely and thorough finishing can eliminate surface defects and ensure the smoothness and appearance quality of the grout layer surface.

[0045] After finishing, the curing stage begins. Once the grout has fully set, immediately cover the grout layer surface with geotextile, and then cover it with a plastic film. The geotextile has excellent water absorption and retention properties, keeping the grout layer surface consistently moist; the plastic film acts as a seal to isolate air and reduce moisture evaporation. Together, they form a moisture-retaining curing system. Under normal temperature conditions, the curing time should be no less than 7 days. In low-temperature environments, the curing time should be extended, and insulation measures such as covering with insulating blankets should be taken to ensure the curing temperature does not fall below 5℃. In high-temperature or windy weather, a sunshade and windproof canopy should be erected above the curing area to avoid direct sunlight and strong winds that accelerate surface moisture evaporation, effectively preventing cracking of the grout layer surface. During the curing period, keep the covering continuously moist to ensure the grout layer is always in a high-humidity environment, promoting the full hydration reaction of the cement. Within 24 hours after grouting is completed, no disturbance, stepping or impact is allowed on the grouting layer and column base plate. After 24 hours, curing should continue. Only after the strength of the grouting layer reaches more than 70% of the design strength as tested by test blocks under the same conditions can subsequent construction procedures be carried out.

[0046] During the grouting process, test blocks cured under the same conditions are prepared simultaneously. The test blocks and the grouting layer are cured in the same environment, and their 3-day and 28-day strengths are tested respectively. The 3-day strength test is used to assess the strength development of the grout material early, allowing for timely detection of problems and remedial measures. The 28-day strength test serves as the basis for the final strength evaluation, ensuring that the load-bearing capacity of the grouting layer meets the structural design requirements.

[0047] S6. After demolding, the density of the grouting layer is tested. If hollow or weak areas are found, drilling and grouting are used for treatment.

[0048] After the curing period and demolding, a comprehensive inspection of the grout layer's density is conducted. The inspection employs a combination of tapping and ultrasonic testing. The tapping method involves striking the surface of the grout layer and analyzing the sound produced to identify hollow areas—hollow areas produce a hollow, dull sound, while dense areas produce a clear, solid sound. This method is simple to operate and allows for rapid preliminary screening. The ultrasonic testing method uses emitted and received ultrasonic waves to accurately determine the density distribution and defect location within the grout layer based on changes in wave velocity and waveform. This method offers high accuracy and reliable results. The combined use of these two methods ensures both inspection efficiency and accuracy.

[0049] If voids or weak areas are found in the grouting layer during inspection, a drilling and grouting process is promptly employed. The specific procedure involves drilling holes with a diameter of 8mm-10mm at the void or weak area. The appropriate hole diameter ensures unobstructed grouting channels without causing excessive damage to the grouting layer. Using a low-pressure method (pressure controlled between 0.2MPa and 0.5MPa), grout of the same proportion as the raw material is slowly injected through the borehole. Low-pressure injection avoids the impact damage to already compacted areas caused by high-pressure grouting, while ensuring the grout slowly and thoroughly fills the voids. After grouting, pressure sealing is performed to allow the injected grout to fully integrate with the original grouting layer under pressure, ensuring that the density and bonding strength of the repaired area meet requirements. This inspection and repair system achieves closed-loop control of the entire grouting quality process, ensuring that the final grouting layer is uniformly dense, free of voids and weak areas.

[0050] This application proposes a method for grouting and compacting large-area column base plates. By optimizing the unidirectional continuous grouting sequence and using an auxiliary vibration device consisting of a hand drill, a conversion joint, and a custom-made spring, the grout flows directionally under the large-area column base plate, allowing for sufficient air release. This achieves uniform compaction without voids throughout the entire area, with a compaction qualification rate consistently exceeding 98%. The custom-made spring can extend into the narrow space under the column base plate for simultaneous grouting and vibration, keeping the grout in a disturbed state throughout its flow. This prevents segregation and bleeding due to stagnation, avoiding the construction difficulties of conventional vibration equipment not being able to reach the area, and effectively ensuring the uniformity and consistency of grout strength. The accompanying hammering method combined with an ultrasonic testing system and a low-pressure grouting repair process ensures that the grouting quality is controllable throughout the entire process, significantly reducing the risk of later settlement and voids, and significantly improving structural safety and durability. At the same time, the construction does not require large equipment, is simple and efficient to operate, and is particularly suitable for high-rise, large-span, and heavy-load steel structure projects.

[0051] The embodiments of this application have been described in detail above. These descriptions are merely preferred embodiments and should not be construed as limiting the scope of this application. All equivalent variations and modifications made within the scope of this application should still fall within the patent coverage of this application.

Claims

1. A method for grouting and compacting a large-face column base plate, characterized by the following steps: include: S1. Roughen the top surface of the short concrete column to expose fresh aggregate, remove slag and dust, and wash it clean with a high-pressure water gun. Wet the base surface 24 hours in advance, and remove standing water 1 hour before grouting to ensure that the base surface is moist inside and dry outside; check the elevation, levelness and position of the column base plate and anchor bolts, and make fine adjustments to areas with uneven gaps to control the grout layer thickness to 30mm-100mm; use an endoscope to check the hidden area under the column base plate to ensure that there are no debris or water accumulation. S2. Set up formwork around the column base plate, attach sealing strips to the inside of the formwork, seal the bottom of the formwork tightly where it contacts the top of the short column in the concrete foundation, and make the formwork height at least 50mm higher than the top surface of the column base plate. S3. Control the particle size of the grouting material to be no greater than 5mm, add water and mix according to the ratio, control the slump to be 300±20mm, the initial setting time to be ≥120min, and let it stand for 2min-3min after mixing to defoam. S4. Using a low-position pouring method, the grout is continuously poured in one direction starting from one end of the column base plate, so that the grout is pushed from one end to the opposite end in sequence. During the grouting process, an auxiliary vibration device is used for vibration. When the grout flows out from the other end of the column base plate and is full and free of air bubbles, the grouting is completed. S5. After grouting, surface finishing is carried out 30-60 minutes after grouting, excess grout is removed and defects are repaired. After final setting, cover with moisturizing material for curing. The curing temperature is not lower than 5℃ and the curing time is not less than 7 days. Disturbance, stepping and impact are prohibited within 24 hours. Subsequent processes can only be carried out after the strength reaches 70% of the design strength. S6. After demolding, the density of the grouting layer is tested. If hollow or weak areas are found, drilling and grouting are used for treatment.

2. The method for grouting and compacting a large-face column base plate according to claim 1, characterized in that, In step S1, after the roughening process exposes fresh aggregate on the base surface, slag and dust are removed, and the surface is washed clean with a high-pressure water gun. The base surface is moistened 24 hours in advance, and standing water is removed 1 hour before grouting to achieve an internally moist and externally dry state.

3. The method for grouting and compacting a large-face column base plate according to claim 1 or 2, characterized in that, In S2, the template is a wooden template or a steel template, the sealing strip pasted on the inside of the template is a double-sided sealing strip, and the bottom of the template and the contact surface with the foundation are sealed tightly with sealing material to prevent grout leakage and air intake.

4. The method for grouting and compacting a large-face column base plate according to claim 1, characterized in that, In S3, the grouting material is fine stone concrete or high-strength non-shrink grouting material. The particle size of the grouting material is not greater than 5mm, the slump is 300±20mm, the initial setting time is ≥120min, and it can be poured after standing for 2min-3min to defoam after stirring.

5. A method for grouting and compacting a large-face column base plate according to any one of claims 1-2 and 4, characterized in that, In S4, the low-position pouring method is to pour the grout from the bottom position on one side of the column base plate. During the grouting process, the grouting should be continuous and simultaneous grouting at multiple points is prohibited.

6. The method for grouting and compacting a large-face column base plate according to claim 5, characterized in that, The vibration auxiliary device includes a hand drill, an adapter, and a custom spring. The hand drill is connected to the custom spring through the adapter. The custom spring extends into the narrow space under the column base plate to perform vibration. The vibration operation is carried out synchronously with the grouting process. The custom spring reciprocates under the column base plate to expel air bubbles in the grout and promote the flow and compaction of the grout.

7. A method for grouting and compacting a large-face column base plate according to any one of claims 1-2, 4, and 6, characterized in that, In S5, the moisture-retaining materials are geotextile and plastic film. After final setting, the geotextile is immediately covered and then covered with plastic film for moisture retention and curing. In low-temperature environments, extend the curing time and take insulation measures; in high-temperature or windy weather, set up sunshade and windproof sheds. After surface finishing, remove excess slurry and repair surface defects. Keep the covering moist during curing to prevent surface cracking.

8. The method for grouting and compacting a large-face column base plate according to claim 7, characterized in that, In S6, the density test is performed by a combination of the impact method and the ultrasonic test; the drilling grouting treatment is as follows: drill holes of Φ8mm-Φ10mm, inject grout of the same proportion using a low-pressure method, and then perform pressure sealing after grouting.

9. The method for grouting and compacting a large-face column base plate according to claim 8, characterized in that, In S5, test blocks under the same conditions are made simultaneously during the grouting process to test the 3-day and 28-day strengths, ensuring that the design requirements are met.

10. A method for grouting and compacting a large-face column base plate according to any one of claims 1-2, 4, 6, 8-9, characterized in that, The large column base plate is a column base plate with a side length of ≥800mm.

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