Construction and installation method for prefabricated column

Abstract

The invention provides a construction and installation method for a prefabricated column. The construction and installation method sequentially comprises the following steps that S1, construction preparation is conducted; s2, hoisting the prefabricated column; s3, prefabricated column installation and perpendicularity correction are carried out; and S4, grouting the prefabricated column. According to the invention, the whole-process standardized operation is realized; technical standards of all links are defined, man-made randomness can be reduced, and construction controllability and repeatability are improved. A metal cushion block and a jack are adopted for fine adjustment, and the perpendicularity deviation is monitored in real time in combination with a theodolite; and steel bar trial pairs are reserved, so that the dislocation risk is avoided in advance. A hoisting safety layering confirmation mechanism is adopted; safety confirmation is performed for three times, and a small mirror is combined to assist in alignment inspection, so that the hoisting accident rate is reduced. Multiple tools are adopted to cooperate with perpendicularity correction, a crowbar, a plumb bob, a guiding rule and a theodolite are combined for use, and an inclined support expansion bolt is matched for fixation, so that the correction time is shortened, and the single-column installation efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of building construction, and in particular to a construction and installation method for prefabricated columns. Background Art

[0002] At present, the existing prefabricated column construction methods have the following problems: (1) Insufficient positioning and measurement accuracy; traditional construction relies on manual measurement, which can easily cause misalignment between prefabricated columns and reserved steel bars due to operational errors, making subsequent adjustments difficult. (2) There are many safety hazards in the lifting process; there is a lack of a phased safety confirmation mechanism (such as insufficient inspection of equipment or paths before lifting), which may cause components to fall or collide. (3) The verticality correction efficiency is low; traditional methods rely on a single tool (such as only using a plumb bob), the adjustment speed is slow, and there is a lack of real-time feedback (such as not combining with a theodolite). (4) Poor control of grouting density. Grouting holes are not tightly sealed or vented, which can easily cause air holes or grout leakage, resulting in insufficient connection strength. (5) Temporary fixation is unreliable; the installation method of inclined supports is arbitrary (such as not using expansion bolts or insufficient number), which can easily cause displacement of prefabricated columns. Summary of the Invention

[0003] In order to solve the above problems, the present invention discloses a construction and installation method for prefabricated columns.

[0004] The specific plan is as follows:

[0005] A construction and installation method for prefabricated columns comprises the following steps in sequence:

[0006] S1. Construction preparation; S2. Lifting of precast columns; S3. Installation and verticality correction of precast columns; S4. Grouting of precast columns.

[0007] Furthermore, step S1 specifically includes:

[0008] S11. Measurement and positioning, correction of reserved steel bars, and on-site acceptance of prefabricated columns;

[0009] S12. Leveling with shims: Place metal blocks at the four corners of the column before hoisting. Confirm the verticality deviation according to the elevation. Use a theodolite to control the verticality. If there is a slight deviation, adjust it with a jack.

[0010] S13. When the columns are initially in place, the reinforcement of the precast columns shall be preliminarily aligned with the reserved reinforcement of the lower precast columns. When no problems are found, they shall be prepared for fixing.

[0011] Furthermore, in step S12, in order to improve the accuracy of leveling, a spatial coordinate system is first established and then the deviation required for adjustment is calculated using a PID dynamic compensation model;

[0012] The spatial coordinate system is:

[0013]

[0014] Among them, Δx and Δy are the two-way correction values of the horizontal plane; wi is the weight coefficient of the i-th measuring point (0.8-1.2); di is the real-time deviation value of the laser rangefinder (mm); ks is the structural stiffness coefficient (range 1.5-3.0); θ is the azimuth angle of the measuring point (0-360°).

[0015] Furthermore, step S2 specifically includes:

[0016] S21. Before hoisting and installing prefabricated columns, the signalman shall confirm the safety of the components and hoist them slowly.

[0017] S22. When the lifting device is about 0.5m above the ground, check the safety of the lifting device.

[0018] S23. After confirming that the lifting device is safe, continue the lifting operation until the construction floor is 300mm away from the floor. Then pause and the installation workers check the positioning line on the floor to stabilize the prefabricated column;

[0019] S24. Use a small mirror to check whether the lower sleeve of the prefabricated column is aligned with the connecting steel bar. After passing the inspection, slowly lower the hook to allow the prefabricated column to fall onto the leveling gasket and place it firmly in place.

[0020] Furthermore, the hoisting process is planned in advance through the hoisting kinematics model, and the formula is:

[0021]

[0022] Where, l is the length of the sling; α is the lifting pitch angle, 15-75°; β is the azimuth angle, 0-360°; C d is the drag coefficient, 0.6-1.2; ρ is the air density, 1.29 kg / m 3 ; m is the mass of the component; A is a constant.

[0023] Furthermore, step S3 specifically includes:

[0024] S31. After the prefabricated columns are in place, two long and short diagonal supports are used to temporarily fix the prefabricated columns. The floor diagonal supports are installed using expansion bolts.

[0025] S32. Verticality correction: Use positioning adjustment tools to fine-tune the precast columns, adjust the verticality of the columns, use a crowbar to move the precast columns, use a plumb bob and a straightedge to correct the position and verticality of the columns, and check with a theodolite; after checking that the horizontal positioning, elevation and verticality of the precast columns are correct, tighten the diagonal supports and remove the sling clips.

[0026] Furthermore, step S4 specifically includes: first, sealing the gap between the bottom of the prefabricated column and the floor slab with mortar, then sealing the grouting holes except for one, inserting a grouting pipe for grouting; when the slurry flows out in a columnar shape, sealing the grouting hole, and within 24 hours after the grouting operation is completed, the components and the grouting connections cannot be subjected to vibration or impact.

[0027] Furthermore, the grouting pressure and the grouting pressure equation during the grouting process are dynamically controlled, and the formula is:

[0028]

[0029] Where P0 is the initial pressure, μ is the slurry viscosity, Q is the flow rate, and λ is the pressure decay coefficient.

[0030] The beneficial effects of the present invention are:

[0031] (1) Standardized operation of the entire process: breaking down the construction into four stages: preparation → lifting → calibration → grouting, and clarifying the technical standards of each link can reduce human arbitrariness and improve the controllability and repeatability of construction.

[0032] (2) High-precision positioning and pre-adjustment: Use metal blocks and jacks for fine-tuning, and use a theodolite to monitor verticality deviation in real time. Reserve steel bars for trial alignment to avoid misalignment risks in advance. This minimizes verticality deviation and increases the success rate of steel bar docking.

[0033] (3) A hierarchical confirmation mechanism for hoisting safety: three safety confirmations (before hoisting → 0.5m from the ground → 300mm from the floor), combined with a small mirror to assist in alignment inspection, reduce the hoisting accident rate.

[0034] (4) Multi-tool coordinated verticality correction: crowbar + plumb bob + straightedge + theodolite are used in combination, and fixed with inclined support expansion bolts, which shortens the correction time and improves the efficiency of single-column installation.

[0035] (5) Grouting density assurance technology: Using gap mortar plugging + single-hole grouting method, the density is determined by the columnar outflow of slurry. It can improve the grouting fullness and compressive strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is the overall flow chart of the present invention.

[0037] Figure 2 Detailed flow chart of step S1 of the present invention.

[0038] Figure 3 Detailed flow chart of step S2 of the present invention.

[0039] Figure 4 Detailed flow chart of step S3 of the present invention. DETAILED DESCRIPTION

[0040] The present invention will be further explained below in conjunction with specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0041] As shown in the figure, the present invention provides a construction and installation method for prefabricated columns, which specifically includes the following steps:

[0042] S1. Construction preparation stage

[0043] S11. Measurement, positioning and acceptance

[0044] Tools: total station (accuracy ±2mm), steel bar position detector.

[0045] Operation: Use a total station to lay out the axis control points and mark the center line of the lower layer of reserved steel bars (allowable deviation ±3mm). Precast column on-site acceptance: Check the inner diameter of the sleeve (deviation ≤1mm) and the flatness of the column base (≤2mm / m).

[0046] S12, gasket leveling and verticality pre-adjustment

[0047] Parameters: Metal spacer specifications: 50mm × 50mm × 5mm (Q235 steel), one at each corner. Jack stroke: 0-50mm, fine-tuning accuracy 0.1mm.

[0048] Operation: Before hoisting the prefabricated column, place pads on the foundation surface and measure the elevation of the four corners of the column top using a theodolite (target height difference ≤ 2mm). If the verticality deviation δ> 1 / 800, activate the jack to adjust the pad thickness (adjustment Δh = δ × column height / 2).

[0049] S13, reserved steel bars test

[0050] Operation: Lift the prefabricated column to a height of 100mm from the foundation surface and manually guide the steel bars into the sleeves (gap ≤ 2mm). If the deviation is too large, use a hydraulic corrector (thrust 5kN) to adjust the position of the lower steel bars.

[0051] S2. Prefabricated column lifting stage

[0052] S21 Hoisting Path Planning and Safety Confirmation

[0053] Equipment: QTZ80 tower crane (10 ton lifting capacity, 60m arm length).

[0054] Path planning: Use the BIM model to generate the lifting path (minimum safety distance 1.5m) to avoid external scaffolding and edge protection.

[0055] Safety check: When lifting to a height of 0.5m, check the balance of the sling tension (the tension difference of the four slings is ≤10%).

[0056] S2. Precise positioning

[0057] Tool: Industrial endoscope (instead of a small mirror), resolution 0.1mm.

[0058] Operation: When the precast column is lowered to 300mm from the floor, use an endoscope to check the alignment of the sleeve and the steel bar (allowable deviation ±3mm). The hook drop speed is ≤0.2m / s, and the final position deviation is ≤2mm.

[0059] S3. Installation and verticality correction

[0060] S31, inclined support installation

[0061] Parameters: Diagonal support specifications: Long support 3m (45° angle with the floor), short support 2m (60° angle). Expansion bolts: M16×120mm (tensile strength ≥15kN).

[0062] Operation: The support point is 1.5m away from the bottom of the column, and the bolts are tightened with a torque wrench (torque 120N·m).

[0063] S32, verticality correction

[0064] Tools: Electronic theodolite (accuracy 2"), laser plumb bob (accuracy 1 / 20000).

[0065] Operation: Measure verticality in both directions (east-west deviation Δx, north-south deviation Δy). If Δx > 3mm, apply a force F = 200N using a crowbar (leverage ratio 1:5), adjusting the displacement by d = Δx / 2. Repeat the measurement until Δx and Δy ≤ 2mm, then tighten the diagonal support.

[0066] S4. Precast column grouting

[0067] S41. Sealing gaps and grouting preparation

[0068] Materials: C40 special grouting material (fluidity ≥300mm), sealing mortar (water-cement ratio 0.3).

[0069] Operation: Use a spatula to seal the gap at the bottom of the column (thickness 15mm), and reserve one grouting hole (hole diameter 20mm)

[0070] S42. Pressure grouting and density testing

[0071] Equipment: High-pressure grouting machine (pressure 0.3-0.5MPa).

[0072] Procedure: Insert the grouting pipe to a depth of 100 mm or more and control the grouting rate at 5 L / min. When the slurry flows out of the drainage hole in a continuous columnar form, seal the hole and maintain pressure for 30 seconds. After 24 hours, perform an ultrasonic test for density (acceptance is determined if the speed of sound is 4000 m / s or more).

[0073] The technical means disclosed in the solutions of the present invention are not limited to those disclosed in the above-mentioned embodiments, but also include technical solutions composed of any combination of the above-mentioned technical features. It should be noted that those skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A construction and installation method for prefabricated columns, characterized in that: The following steps are included in sequence: S1. Construction preparation; S2. Lifting of precast columns; S3. Installation and verticality correction of precast columns; S4. Grouting of precast columns.

2. A construction and installation method for prefabricated columns according to claim 1, characterized in that: Step S1 specifically includes: S11. Measurement and positioning, calibration of reserved steel bars, and on-site acceptance of prefabricated columns; S12. Leveling with shims: Place metal blocks at the four corners of the column before hoisting. Confirm the verticality deviation according to the elevation. Use a theodolite to control the verticality. If there is a slight deviation, adjust it with a jack. S13. When the columns are initially in place, the reinforcement of the precast columns shall be preliminarily aligned with the reserved reinforcement of the lower precast columns. When no problems are found, they shall be prepared for fixing.

3. A construction and installation method for prefabricated columns according to claim 2, characterized in that: In step S12, in order to improve the accuracy of leveling, a spatial coordinate system is first established and then the deviation required for adjustment is calculated using a PID dynamic compensation model; The spatial coordinate system is: Among them, Δx and Δy are the two-way correction values of the horizontal plane; wi is the weight coefficient of the i-th measuring point, which ranges from 0.8 to 1.2; di is the real-time deviation value of the laser rangefinder; ks is the structural stiffness coefficient, which ranges from 1.5 to 3.0; θ is the azimuth angle of the measuring point, which ranges from 0 to 360°.

4. A construction and installation method for prefabricated columns according to claim 1, characterized in that: Step S2 specifically includes: S21. Before hoisting and installing prefabricated columns, the signalman shall confirm the safety of the components and hoist them slowly. S22. When the lifting device is about 0.5m above the ground, check the safety of the lifting device. S23. After confirming that the lifting device is safe, continue the lifting operation until the construction floor is 300mm away from the floor. Then pause and the installation workers check the positioning line on the floor to stabilize the prefabricated column; S24. Use a small mirror to check whether the lower sleeve of the prefabricated column is aligned with the connecting steel bar. After passing the inspection, slowly lower the hook to allow the prefabricated column to fall onto the leveling gasket and place it firmly in place.

5. A construction and installation method for prefabricated columns according to claim 4, characterized in that: During the lifting process, advance planning is performed through the lifting kinematics model, and the formula is: Where, l is the length of the sling; α is the lifting pitch angle, 15-75°; β is the azimuth angle, 0-360°; C d is the drag coefficient, 0.6-1.2; ρ is the air density, 1.29 kg / m 3 ; m is the mass of the component; A is a constant.

6. A construction and installation method for prefabricated columns according to claim 1, characterized in that: Step S3 specifically includes: S31. After the prefabricated columns are in place, two long and short diagonal supports are used to temporarily fix the prefabricated columns. The floor diagonal supports are installed using expansion bolts. S32. Verticality correction: Use positioning adjustment tools to fine-tune the precast columns, adjust the verticality of the columns, use a crowbar to move the precast columns, use a plumb bob and a straightedge to correct the position and verticality of the columns, and check with a theodolite; after checking that the horizontal positioning, elevation and verticality of the precast columns are correct, tighten the diagonal supports and remove the sling clips.

7. A construction and installation method for prefabricated columns according to claim 1, characterized in that: Step S4 specifically includes: first, sealing the gap between the bottom of the prefabricated column and the floor slab with mortar, then sealing the grouting holes except for one, inserting the grouting pipe for grouting; when the slurry flows out in a columnar shape, sealing the grouting hole. Within 24 hours after the grouting operation is completed, the components and the grouting connection must not be subjected to vibration or impact.

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