Hoisting and mounting method for prefabricated staircase

Abstract

The invention provides a hoisting and mounting method for a prefabricated stair. The hoisting and mounting method sequentially comprises the steps of preparation work before hoisting, hoisting of the prefabricated stair and mounting of the prefabricated stair. The concrete process comprises the steps of surveying and setting out, reserved bolt positioning detection and correction, mortar smearing and leveling, preparation work before hoisting, prefabricated stair entering and hoisting, judging whether bolts are aligned with holes or not, determining the positions and the elevations, and blocking the ends with fine aggregate concrete. Whether the bolt observes the hole through the mirror or not is judged, the position and the elevation are determined to be medium, if the deviation is small, a crowbar is used for adjustment, and if the deviation is large, the bolt is hoisted and located again. According to the method, the construction concept is driven through an algorithm, a traditional hoisting process depending on manual experience is converted into a computable, controllable and optimizable intelligent manufacturing process, systematic breakthrough is achieved in the aspects of precision, efficiency, safety, durability and the like, and key technical support is provided for transformation of fabricated buildings to intelligent construction.

Description

Technical Field

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

[0002] At present, the traditional prefabricated stair hoisting method has the following technical pain points:

[0003] (1) Insufficient positioning accuracy: Defects: Traditional surveying and layout rely on manual line drawing, and the accumulated errors result in axis deviations greater than 10mm and elevation errors greater than 5mm, which cannot meet the high-precision installation requirements of prefabricated buildings. Case: Due to manual measurement errors, a staircase collided with a structural column after installation on a project, forcing rework and a 15-day delay in construction.

[0004] (2) Uncontrolled Lifting Mechanics: Defect: The distribution of lifting point tension is estimated based on experience, without considering the impact of dynamic loads. When the lifting angle is greater than 3°, it is easy to cause structural stress concentration (local stress greater than 0.8f_y), posing a safety hazard. Data: Statistics show that 80% of traditional lifting accidents are caused by uneven load distribution on the lifting equipment.

[0005] (3) Inefficient alignment and adjustment: Defects: Bolt hole alignment relies on manual visual inspection (mirror reflection method), with a hole position deviation detection accuracy of only ±5mm. The adjustment process requires repeated trial lifting, and a single adjustment takes >30 minutes. Experiment: Comparative tests show that the traditional method requires an average of three trial liftings to achieve the installation accuracy requirements.

[0006] (4) Poor joint durability: Defects: Ordinary fine stone concrete shrinkage rate > 0.05%, cracking rate of the plugged parts within 2 years as high as 40%, and steel anchorage force attenuation rate > 15%. Inspection: Infrared thermal imaging shows the presence of a cold bridge effect in traditional plugged parts, increasing energy loss by 20%. Summary of the Invention

[0007] In order to solve the above problems, the present invention discloses a method for hoisting and installing a prefabricated staircase.

[0008] The specific plan is as follows:

[0009] A method for hoisting and installing a prefabricated staircase is characterized in that it includes, in sequence, preparatory work before hoisting, hoisting of the prefabricated staircase and installation of the prefabricated staircase; the specific process is: measuring and laying out, reserved bolt positioning detection and correction, mortar application and leveling, preparatory work before hoisting, prefabricated staircase delivery and hoisting, judging whether the bolts are aligned with the holes, determining the position and elevation, and sealing the ends with fine stone concrete; wherein, judging whether the bolts are aligned with the holes is performed by observing through a mirror, and when determining the position and elevation, if the deviation is small, a crowbar is used to adjust, and if the deviation is large, the staircase is re-hoisted and placed into position.

[0010] Furthermore, the pre-hoisting preparations include:

[0011] (11) According to the construction drawings, pop up the stair installation control line and review the control line and elevation; reserve a 30mm gap on the side of the staircase according to the structural column to reserve space for the subsequent initial installation of the plaster layer;

[0012] (12) Lay 20mm thick M15 mortar on the upper and lower beams of the staircase for leveling.

[0013] Furthermore, the BIM model is used to derive the stair hoisting positioning parameter set P = {xi,yi,zi,θi}, where i = 1,2,...,n represents the control point number, and the installation error mathematical model is established: E = Σ(Δxi 2 +Δyi 2 +Δzi 2 )+λΣΔθi 2 ≤εmax; where λ = 0.8 is the angle error weight coefficient εmax = 15mm 2 is the total error threshold; an M15 mortar leveling layer is laid on the ladder beam surface, and its thickness t satisfies t=20±0.5e^{-0.03T}mm, where T is the ambient temperature (℃).

[0014] Furthermore, the hoisting of prefabricated stairs includes:

[0015] (21) Tighten the eyebolts and embedded sleeves, adjust the length of the rigging chain, make the staircase rest platform in a horizontal position, and the test lifting height shall not exceed 1m;

[0016] (22) Ensure that the prefabricated ladder rest platform remains horizontal during the lifting process; use an adjustable horizontal lifting beam to lift it into place evenly, with more than 4 lifting points.

[0017] Furthermore, a four-dimensional lifting point tension distribution algorithm is used during hoisting: Fk = Ks (W / Σcosαk) [1 + 0.2sin(β / 2)]; where Fk is the tension of the kth lifting point (kN), Ks = 1.5 is the safety factor, W is the deadweight of the ladder section (kN), αk is the angle between the lifting cable and the vertical direction (°), and β is the inclination angle of the ladder section (°); the structural stress ζmax ≤ 0.6f_y is calculated in real time during the hoisting process, and fy = 235 MPa is the yield strength of Q235B steel.

[0018] Furthermore, to determine whether the bolt is aligned with the hole, first establish the bolt hole alignment offset compensation equation: Δ=√(Δx 2 +Δy 2)+3|Δθ|≤Δ_lim; when Δ≤5mm, the hydraulic fine-tuning system is activated, and its adjustment amount satisfies: δ=Δ·e^{-μt}+0.1∫Δdt; where μ=0.05 is the damping coefficient, and t is the adjustment time (s); when the offset Δ>5mm, the repositioning algorithm is triggered, and a new lifting path function R(t)=R0+vt+0.5a·t is generated. 2 .

[0019] Furthermore, the installation of prefabricated stairs includes: when it is hoisted above the stairs, the construction workers guide it to the correct position, and when the prefabricated stairs are in place, first insert the reserved round holes at the upper and lower ends into the Inside the steel bar head, use a crowbar or other device to precisely position the component according to the control line, and the component is required to be placed stably.

[0020] Furthermore, the expansion rate of fine aggregate concrete satisfies: ε(t) = ε∞(1-e^{-kt}); where ε∞ = 0.03% is the final expansion rate, k = 0.15d-1 is the expansion rate coefficient, and the curing temperature is controlled at 20±2°C.

[0021] The beneficial effects of this invention are: by driving the construction concept through algorithms, the traditional lifting process that relies on manual experience is transformed into a calculable, controllable and optimizable intelligent manufacturing process, achieving systematic breakthroughs in dimensions such as precision, efficiency, safety and durability, and providing key technical support for the transformation of prefabricated buildings to intelligent construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Flowchart of the present invention.

[0023] Figure 2 This is a schematic diagram of the preparation work before lifting.

[0024] Figure 3 Schematic diagram of the lifting of prefabricated stairs.

[0025] Figure 4 Schematic diagram of prefabricated stair installation. DETAILED DESCRIPTION

[0026] 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.

[0027] As shown in the figure, the present invention provides a method for lifting and installing prefabricated stairs, which includes preparatory work before lifting, lifting of prefabricated stairs and installation of prefabricated stairs in sequence; the specific process is: measuring and laying out, reserved bolt positioning detection and correction, mortar application and leveling, preparatory work before lifting, prefabricated stairs entering and lifting, judging whether the bolts are aligned with the holes, determining the position and elevation, and sealing the ends with fine stone concrete; wherein, whether the bolts are aligned with the holes is judged by observing through a mirror, and when the position and elevation are determined, if the deviation is small, it is adjusted with a crowbar, and if the deviation is large, it is lifted and lowered into place again.

[0028] In this embodiment, the pre-hoisting preparations include:

[0029] (11) According to the construction drawings, pop up the stair installation control line and review the control line and elevation; reserve a 30mm gap on the side of the staircase according to the structural column to reserve space for the subsequent initial installation of the plaster layer;

[0030] (12) Lay 20mm thick M15 mortar on the upper and lower beams of the staircase for leveling.

[0031] In this embodiment, the BIM model is used to derive the stair hoisting positioning parameter set P = {xi, yi, zi, θi}, where i = 1, 2, ..., n represents the control point number, and the installation error mathematical model is established: E = Σ(Δxi 2 +Δyi 2 +Δzi 2 )+λΣΔθi 2 ≤εmax; where λ = 0.8 is the angle error weight coefficient εmax = 15mm 2 is the total error threshold; an M15 mortar leveling layer is laid on the ladder beam surface, and its thickness t satisfies t=20±0.5e^{-0.03T}mm, where T is the ambient temperature (℃).

[0032] In this embodiment, the hoisting of prefabricated stairs includes:

[0033] (21) Tighten the eyebolts and embedded sleeves, adjust the length of the rigging chain, make the staircase rest platform in a horizontal position, and the test lifting height shall not exceed 1m;

[0034] (22) Ensure that the prefabricated ladder rest platform remains horizontal during the lifting process; use an adjustable horizontal lifting beam to lift it into place evenly, with more than 4 lifting points.

[0035] In this embodiment, a four-dimensional lifting point tension distribution algorithm is used during hoisting: Fk = Ks·(W / Σcosαk)·[1+0.2sin(β / 2)]; where Fk is the kth lifting point tension (kN), Ks=1.5 is the safety factor, W is the deadweight of the ladder section (kN), αk is the angle between the lifting cable and the vertical direction (°), and β is the inclination angle of the ladder section (°); the structural stress ζmax≤0.6f_y is calculated in real time during the hoisting process, and fy=235MPa is the yield strength of Q235B steel.

[0036] In this embodiment, to determine whether the bolt is aligned with the hole, first establish the bolt hole alignment offset compensation equation: Δ=√(Δx 2 +Δy 2 )+3|Δθ|≤Δ_lim; when Δ≤5mm, the hydraulic fine-tuning system is activated, and its adjustment amount satisfies: δ=Δ·e^{-μt}+0.1∫Δdt; where μ=0.05 is the damping coefficient, and t is the adjustment time (s); when the offset Δ>5mm, the repositioning algorithm is triggered, and a new lifting path function R(t)=R0+vt+0.5a·t is generated. 2 .

[0037] In this embodiment, the installation of the prefabricated stairs includes: when it is hoisted above the stairs, the construction workers guide it to the correct position, and when the prefabricated stairs are in place, first insert the reserved round holes at the upper and lower ends into the Inside the steel bar head, use a crowbar or other device to precisely position the component according to the control line, and the component is required to be placed stably.

[0038] In this embodiment, the expansion rate of fine aggregate concrete satisfies: ε(t) = ε∞(1-e^{-kt}); where ε∞ = 0.03% is the final expansion rate, k = 0.15d-1 is the expansion rate coefficient, and the curing temperature is controlled at 20±2°C.

[0039] Example (a residential building project):

[0040] 1. Preparation before lifting

[0041] Step 1: Measurement and verification

[0042] A total station was used to draw stair installation control lines at the ladder beams and landings. The line width was 2mm, and the error was controlled within ±3mm. A review revealed that the original structural column was offset by 5mm. After adjusting the control lines, a 30mm gap was reserved between the stair side and the structural column (for the plaster layer).

[0043] Step 2: Reserve bolt positioning detection

[0044] After checking the position of the M20 bolt sleeves embedded in the ladder beam, it was found that the No. 3 sleeve had a deviation of 8mm. It was removed with a pneumatic wrench and the reinforcement was re-positioned to ensure that the center deviation of all sleeves was ≤2mm.

[0045] Step 3: Construction of mortar leveling layer

[0046] Lay 20mm thick M15 cement mortar on the contact surface of the upper and lower ladder beams, use a laser level to control the leveling layer elevation, fill local depressions with mortar, and the final flatness error is ≤2mm.

[0047] 2. Prefabricated stair lifting

[0048] Step 4: Installation of lifting equipment and trial lifting

[0049] Use 4 M24 eyebolts to connect with the embedded sleeve of the prefabricated staircase, and set the torque value to 320N·m (qualified by torque wrench test). Adjust the adjustable horizontal beam so that the 4 The wire ropes are of uniform length and the chain rigging is at a 45° angle. A test hoist is conducted at a height of 0.8m and allowed to hover for 2 minutes. Observe that there is no slippage at the hoisting point and no cracks in the structure.

[0050] Step 5: Level Control

[0051] A wireless inclination sensor (accuracy 0.1°) was installed to monitor the staircase's inclination in real time. During the lifting process, the hydraulic system of the lifting beam was adjusted to maintain a horizontal deviation of the rest platform ≤1°.

[0052] 3. Prefabricated staircase installation

[0053] Step 6: Position the bolts in the holes

[0054] When the staircase was hoisted to a height of 200 mm from the mounting surface, the construction crew paused. Using an LED-illuminated endoscope (10 mm diameter), they penetrated the bolt holes and observed that bolt No. 2 was misaligned. After fine-tuning the horizontal displacement of the staircase by 15 mm using a hand chain hoist, all four bolts were 100% aligned.

[0055] Step 7: Fine-tune and fix the elevation

[0056] After the staircase was initially in place, it was found that the north end was 8mm lower: Local deviation (≤5mm): Use a 10kg crowbar to lift the south side and insert a 2mm steel shim to adjust; Overall deviation: Because the west side deviation reached 12mm, the mortar layer was cleaned after re-lifting and re-sanding.

[0057] Step 8: Detailing

[0058] Use C30 fine stone concrete to seal the end and insert The concrete was compacted with a vibrating rod and ultrasonic testing was performed after 3 days of curing, and the density reached 98%.

[0059] 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 method for hoisting and installing a prefabricated staircase, characterized in that: It includes the preparation work before lifting, lifting of prefabricated stairs and installation of prefabricated stairs in sequence; the specific process is: measurement and layout, reserved bolt positioning detection and correction, mortar application and leveling, preparation work before lifting, prefabricated stairs entering and lifting, judging whether the bolts are aligned with the holes, determining the position and elevation, and sealing the ends with fine stone concrete; among them, judging whether the bolts are aligned with the holes is done by observing through a mirror, and when determining the position and elevation, if the deviation is small, use a crowbar to adjust it, and if the deviation is large, re-lift and lower it into position.

2. The method for hoisting and installing a prefabricated staircase according to claim 1, characterized in that: Preparations before lifting include: (11) According to the construction drawings, pop up the stair installation control line and review the control line and elevation; reserve a 30mm gap on the side of the staircase according to the structural column to reserve space for the subsequent initial installation of the plaster layer; (12) Lay 20mm thick M15 mortar on the upper and lower beams of the staircase for leveling.

3. The method for hoisting and installing a prefabricated staircase according to claim 2, characterized in that: Apply the BIM model to derive the stair hoisting positioning parameter set P = {xi,yi,zi,θi}, where i = 1,2,...,n represents the control point number, and establish the installation error mathematical model: E = Σ(Δxi 2 +Δyi 2 +Δzi 2 )+λΣΔθi 2 ≤εmax; where λ = 0.8 is the angle error weight coefficient εmax = 15mm 2 is the total error threshold; an M15 mortar leveling layer is laid on the ladder beam surface, and its thickness t satisfies t=20±0.5e^{-0.03T}mm, where T is the ambient temperature.

4. The method for hoisting and installing a prefabricated staircase according to claim 1, characterized in that: Prefabricated stair lifting includes: (21) Tighten the eyebolts and embedded sleeves, adjust the length of the rigging chain, make the staircase rest platform in a horizontal position, and the test lifting height shall not exceed 1m; (22) Ensure that the prefabricated ladder rest platform remains horizontal during the lifting process; use an adjustable horizontal lifting beam to lift it into place evenly, with more than 4 lifting points.

5. The method for hoisting and installing a prefabricated staircase according to claim 4, characterized in that: During hoisting, a four-dimensional lifting point tension distribution algorithm is used: Fk = Ks (W / Σcosαk) [1 + 0.2sin(β / 2)]; where Fk is the tension of the kth lifting point, Ks = 1.5 is the safety factor, W is the deadweight of the ladder section, αk is the angle between the lifting cable and the vertical direction, and β is the inclination angle of the ladder section. The structural stress ζmax ≤ 0.6f_y is calculated in real time during the hoisting process, and fy = 235 MPa is the yield strength of Q235B steel.

6. The method for hoisting and installing a prefabricated staircase according to claim 1, characterized in that: To determine whether the bolt is aligned with the hole, first establish the bolt hole offset compensation equation: Δ=√(Δx 2 +Δy 2 )+3|Δθ|≤Δ_lim; when Δ≤5mm, the hydraulic fine-tuning system is activated, and its adjustment amount satisfies: δ=Δ·e^{-μt}+0.1∫Δdt; where μ=0.05 is the damping coefficient, and t is the adjustment time; when the offset Δ>5mm, the repositioning algorithm is triggered, and a new lifting path function R(t)=R0+vt+0.5a·t is generated. 2 .

7. The method for hoisting and installing a prefabricated staircase according to claim 1, characterized in that: The installation of prefabricated stairs includes: when it is hoisted above the stairs, the construction workers guide it to the correct position, and when the prefabricated stairs are in place, first insert the reserved round holes at the upper and lower ends into the Inside the steel bar head, use a crowbar or other device to precisely position the component according to the control line, and the component is required to be placed stably.

8. The method for hoisting and installing a prefabricated staircase according to claim 1, characterized in that: The expansion rate of fine aggregate concrete satisfies: ε(t) = ε∞(1-e^{-kt}); where ε∞ = 0.03% is the final expansion rate, k = 0.15d -1 is the expansion rate coefficient, and the curing temperature is controlled at 20±2℃.

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