UHPC fabricated prefabricated stair structure and construction method thereof

Abstract

The invention relates to the technical field of fabricated buildings, and discloses a UHPC fabricated prefabricated stair structure and a construction method thereof. The UHPC fabricated prefabricated stair structure comprises unit type steps, plate type steel stair beams and three-way adjusting devices; bearing bolts are pre-buried in the bottoms of the unit type UHPC steps, and reserved holes matched with the bearing bolts are formed in the plate type steel ladder beams; the plate type steel ladder beam is connected with the building supporting platform through a three-way adjusting device, and the three-way adjusting device allows the steel ladder beam to be freely adjusted in the front-back direction, the left-right direction and the up-down direction. A traditional integral stair is disassembled into a modular structure of unit type UHPC steps and plate type steel stair beams, factory prefabrication and on-site rapid assembly are achieved, prefabricated parts are poured through high-precision steel molds, the size error is smaller than 0.3 mm, bolt connection and a three-way adjusting device are adopted on site, the construction period is greatly shortened, on-site formwork erecting is reduced, and the construction cost is reduced. The construction efficiency is improved; the labor intensity is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of prefabricated buildings, and in particular to a UHPC prefabricated staircase structure and a construction method thereof. Background Art

[0002] In the context of building industrialization and green building development, prefabricated building technology has become the mainstream direction of the industry due to its high efficiency, environmental protection and standardization. As a key component of prefabricated buildings, the technological innovation of prefabricated stairs directly affects the process of building industrialization. At present, the research on prefabricated stairs at home and abroad mainly focuses on the fields of modular design, connection node performance and material lightweighting.

[0003] In the current traditional construction process, most of the stairs are constructed using cast-in-place structures. Traditional cast-in-place staircase structures are difficult to support on-site, the quality of construction joints is difficult to control, and the labor and wood consumption are large. With the continuous innovation and development of the construction industry, the market labor price continues to rise, and the resulting increase in construction costs, the construction industry will inevitably gradually develop in the direction of industrialization and factory production. As prefabricated construction technology becomes more and more mature and perfect, the construction industry will use more and more prefabricated models. Prefabricated stairs, as an indispensable part of prefabricated structures, will inevitably be promoted and applied on a large scale. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a UHPC assembled prefabricated staircase structure and a construction method thereof, which solves the problems of difficulty in on-site formwork support and difficulty in controlling the quality of construction joints in traditional cast-in-place staircase structures.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: A UHPC prefabricated staircase structure, comprising: Unitized steps, plate steel ladder beams and three-way adjustment device; The unit-type UHPC step bottom is pre-buried with load-bearing bolts, and the plate-type steel ladder beam is provided with reserved holes matching the load-bearing bolts; The plate-type steel ladder beam is connected to the building support platform through a three-way adjustment device, and the three-way adjustment device allows the steel ladder beam to be freely adjusted in three directions: front and back, left and right, and up and down.

[0006] By adopting the above technical solutions, load-bearing bolts are embedded at the bottom of the unitized UHPC steps and are matched with the reserved holes of the plate-type steel ladder beam. The plate-type steel ladder beam is connected to the building support platform through a three-way adjustment device and allows three-way free adjustment. Among them, the unitized UHPC steps are precast into an L-shaped structure with reactive powder concrete, and a fair-faced concrete decorative layer is integrally cast on the surface. The single-point bearing capacity is >1 ton, and the total weight of a single flight is <300 kg. It can be transported by a construction elevator, eliminating the risk of formwork support operations and construction joint leakage on-site, and achieving a balance between lightweight and high strength. The plate-type steel ladder beam is a channel steel beam, with a matching card slot on the inner side and filled with an elastic shock-absorbing gasket. Dry and rapid assembly is achieved through bolt-slot composite connection. The shear strength is ≥80 kN and the noise reduction effect is ≥15 dB. The three-way adjustment device consists of horizontal / longitudinal screws, vertical bolts and universal joints. Combined with a laser positioning unit and a terminal control system, millimeter-level precision adjustment can be completed within 20 minutes (the horizontal deviation is ≤2 mm / 3 m, and the vertical deviation is ≤3 mm / full height), digesting the construction errors of the building support platform.

[0007] Preferably, the unitized step is an L-shaped structure, with a fair-faced concrete decorative layer integrally cast on its surface, and the single-point bearing capacity is greater than 1 ton.

[0008] Preferably, the plate-type steel ladder beam is a channel steel beam, with a card slot on the inner side that matches the bottom of the unitized step, and the card slot is filled with an elastic shock-absorbing gasket.

[0009] Preferably, the three-way adjustment device includes a horizontal adjustment screw, a longitudinal adjustment screw and a vertical adjustment bolt, and each adjustment component is connected through a universal joint to achieve three-dimensional fine adjustment.

[0010] Preferably, the unitized step is made of reactive powder concrete material, and the total weight of a single-flight staircase is less than 300 kg.

[0011] Preferably, a construction method for a UHPC assembled precast staircase structure includes the following steps: S1. Prefabrication production: Pour the unitized steps and the plate-type steel ladder beam using high-precision steel molds; S2. Transportation: Transport the precast components to the construction site in batches through a construction elevator; S3. On-site assembly: Fix the plate-type steel ladder beam to the support platform through a three-way adjustment device, and then connect the unitized steps to the reserved holes through load-bearing bolts; S4. Adjustment and calibration: Adjust the horizontal and vertical levels of the plate-type steel ladder beam through the three-way adjustment device; S5. Tightening and locking: After the adjustment is completed, tighten all bolts and install locknuts.

[0012] Preferably, in S3, a laser positioning unit is used to assist the alignment installation of the unit steps and the plate-type steel ladder beams, and the laser positioning unit feeds back the installation position deviation data to the terminal control system in real time to achieve millimeter-level precision adjustment.

[0013] Preferably, in S3, epoxy resin glue is filled between the load-bearing bolts and the reserved holes to enhance the shear strength and sealing of the connection nodes.

[0014] Preferably, in S4, the adjustment process of the three-way adjustment device is implemented by an electric drive mechanism, and the operator controls the adjustment direction and amplitude by a handheld remote controller.

[0015] Preferably, after S5 is completed, a protective coating is sprayed on the surface of the unit step to improve wear resistance and anti-fouling performance.

[0016] The present invention provides a UHPC prefabricated staircase structure and a construction method thereof, which has the following beneficial effects: 1. The present invention disassembles the traditional integral staircase into a modular structure of unitized UHPC steps and plate-type steel ladder beams to achieve factory prefabrication and rapid on-site assembly. The prefabricated components are cast through high-precision steel molds with a dimensional error of less than 0.3mm. Bolt connections and three-way adjustment devices are used on-site, which greatly shortens the construction period, reduces on-site formwork, improves construction efficiency and reduces labor intensity.

[0017] 2. The pre-buried bearing bolts at the bottom of the step and the reserved holes of the steel ladder beam are filled with epoxy resin glue to form a rigid connection node with a shear strength of ≥80kN, which has both sealing and anti-seepage properties. The elastic shock-absorbing gasket is embedded in the inner groove of the steel ladder beam, which absorbs vibration energy through compression deformation and significantly reduces the noise transmission between floors.

[0018] 3. The present invention uses dry construction, does not require grouting, reduces construction waste and material waste, and uses Q345B channel steel for steel ladder beams, which has a 40% higher bending stiffness than traditional I-beams. The maximum span can reach 6m, which is suitable for large-space construction needs and reduces material consumption by 30%. The prefabrication model reduces on-site labor and wood consumption, which is in line with the development trend of green buildings and industrialization. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a cross-sectional view of the bolt connection between the step and the plate-type steel ladder beam of the present invention; Figure 2 It is a schematic diagram of a node diagram of a bolt connection between a support platform and a plate-type steel ladder beam of the present invention; Figure 3 It is a three-dimensional schematic diagram of the plate-type steel ladder beam of the present invention; Figure 4 It is a three-dimensional schematic diagram of the installation of the unit step of the present invention.

[0020] Among them, 1. Unitary step; 2. Plate - type steel ladder beam; 21. Hole; 3. Three - way adjustment device; 4. Support platform. Specific implementation mode

[0021] The technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present invention.

[0022] Please refer to the attached Figure 1 - attached Figure 3 , the embodiment of the present invention provides a UHPC assembled precast staircase structure, including: Unitary step 1, plate - type steel ladder beam 2 and three - way adjustment device 3; A bearing bolt is pre - embedded at the bottom of the unitary step 1, and a reserved hole 21 matching the bearing bolt is provided on the plate - type steel ladder beam 2; The plate - type steel ladder beam 2 is connected to the building support platform 4 through a three - way adjustment device 3, and the three - way adjustment device 3 allows the plate - type steel ladder beam 2 to be freely adjusted in the front - back, left - right, and up - down directions.

[0023] Specifically, the unitary step 1 is pre - fabricated in a high - precision steel mold in a factory using ultra - high - performance reactive powder concrete UHPC. A bearing bolt is pre - embedded inside it, and the steam curing process is used to ensure the ultra - high performance of the material, with a compressive strength ≥ 150 MPa and a flexural strength ≥ 25 MPa. The plate - type steel ladder beam 2 is a channel steel beam, with a reserved card slot and hole 21 on the inner side, forming a bolt - card slot composite connection system with the bearing bolt at the bottom of the step. The pre - embedded bolt and the reserved hole 21 cooperate with each other, which not only ensures the installation convenience but also realizes rigid fixation through subsequent filling with epoxy resin glue 24. An elastic shock - absorbing gasket is embedded in the card slot 22, which absorbs vibration energy through elastic deformation and reduces the noise transmission, with a noise reduction effect ≥ 15 dB, thus solving the problems of easy water seepage at the construction joint of traditional cast - in - place stairs and low on - site formwork support efficiency. The three - way adjustment device 3 belongs to the prior art and will not be elaborated here, forming a freedom adjustment system.

[0024] The single - point bearing capacity of the unitary step 1 > 1 ton, and the total weight of a single - flight < 300 kg, which can be transported by a construction elevator 8, breaking through the dependence on tower cranes and adapting to the narrow construction environment of high - rise buildings. The plate - type steel ladder beam 2 is made of Q345B steel, and the channel - shaped cross - section design increases the flexural stiffness by 40%, with a maximum span of up to 6 m, meeting the requirements of large - space buildings. The fair - faced concrete finish layer integrally cast on the surface eliminates the later decoration process. Combined with the sprayed protective coating, the wear resistance is increased by 50%.

[0025] During the construction stage, the laser positioning unit projects a reference line onto the support platform 4, and the terminal control system compares the design coordinates with the measured data in real time and automatically generates adjustment instructions. Taking a high-rise residential project as an example, steel molds are processed by numerically controlled machine tools, and the dimensional error of the unitary step 1 is < 0.3 mm. On-site, the three-way adjustment device 3 is driven by a remote control, and the accurate positioning of a single-run staircase is completed within 20 minutes. The acceptance standard requires that the flatness deviation of the steel plate stair beam 2 is ≤ 2 mm / 3 m, the perpendicularity deviation is ≤ 3 mm / full height, and the torque value of the bolt connection node reaches 50 N·m ± 5%, ensuring the structural safety and durability.

[0026] Please refer to the appendix Figure 4 , the unitary step 1 is of L-shaped structure, and its surface is integrally cast with a fair-faced concrete finish layer, and the single-point bearing capacity is greater than 1 ton; the steel plate stair beam 2 is a channel steel beam, and a card slot matching the bottom of the unitary step 1 is provided inside it, and an elastic shock-absorbing gasket is filled in the card slot.

[0027] Specifically, the unitary step 1 is designed with an L-shaped structure. Its vertical flange and horizontal tread are integrally formed. Combining the high-strength characteristics of ultra-high performance concrete (UHPC), the compressive strength is ≥ 150 MPa, and the internal pre-embedded HRB400 steel bar skeleton, the single-point static load bearing capacity > 1 ton, which can resist the impact load of dense crowds or heavy equipment. The fair-faced concrete finish layer 12 integrally cast on the surface is completed in the factory prefabrication stage. Using the self-compacting property of UHPC, a mirror effect without air bubbles and cracks is achieved, and the wear resistance coefficient is ≥ 0.8, eliminating the need for secondary decoration on site, and the carbonation resistance performance reaches more than 100 years, suitable for humid or corrosive environments. The steel plate stair beam 2 uses a Q345B channel steel beam. The U-shaped cross-section design increases its flexural stiffness by 40% compared with the traditional I-beam, and the maximum span can reach 6 m; the internal card slot 22 matches the L-shaped structure at the bottom of the step with a precise tolerance of ± 0.3 mm, and a high-elastic polyurethane gasket 23 is embedded. The vibration energy is absorbed through compression deformation, and the noise reduction effect is ≥ 15 dB, significantly reducing the noise transmission between floors.

[0028] The modular design of the L-shaped step and the channel steel beam, combined with the clearance fit of the bearing bolts and the reserved holes 21 and the filling of epoxy resin glue, form a rigid connection node with a shear strength ≥ 80 kN, realizing the rapid installation of a single-run staircase on site in 30 minutes. The traditional in-situ casting takes 8 hours. The surface of the steel plate stair beam 2 is double-anti-corrosion with epoxy zinc-rich primer and polyurethane topcoat. Combining the durability of the elastic shock-absorbing gasket, the cost is reduced by 50%. The staircase with a single-run total weight < 300 kg can be transported by a construction elevator, adapting to the narrow environment of high-rise buildings; after being fully loaded with 1.5 t static load for 24 hours, the deflection of the step is < L / 800, and the mid-span deformation of the steel stair beam is ≤ 3 mm.

[0029] Please refer to the appendix Figure 2, the three-way adjustment device 3 includes a lateral adjustment screw, a longitudinal adjustment screw, and a vertical adjustment bolt. Each adjustment component is connected by a universal joint to achieve fine adjustment in three-dimensional space; the unitary tread 1 is made of ultra-high performance concrete (UHPC) material, and the total weight of a single flight of stairs is less than 300 kg.

[0030] Specifically, the three-way adjustment device 3 is used to eliminate the horizontal construction error of the building support platform 4. A single person can complete the three-dimensional positioning of a single flight of stairs within 10 minutes. After the adjustment is completed, the locking nut fixes the universal joint to form a rigid joint with a lateral displacement resistance capacity of ≥5 kN / m, ensuring the long-term stability of the stairs.

[0031] The unitary tread 1 is made of ultra-high performance concrete (UHPC) material. The L-shaped structure design optimizes the cross-sectional shape, with a tread thickness of 40 mm and a flange height of 120 mm, achieving lightweight. The total weight of a single flight of stairs is <300 kg, and it can be vertically transported by a construction elevator, adapting to the narrow construction environment of high-rise buildings. At the same time, the high density of UHPC enables the integrally cast fair-faced finish layer 12 on the tread surface, with a wear resistance coefficient of ≥0.8.

[0032] A construction method for a UHPC prefabricated stair structure includes the following steps: S1. Prefabrication production: The unitary tread 1 and the plate-shaped steel stair beam 2 are cast using high-precision steel molds. S2. Transportation: The prefabricated components are transported to the construction site in batches by a construction elevator. S3. On-site assembly: The plate-shaped steel stair beam 2 is fixed to the support platform 4 through the three-way adjustment device 3, and then the unitary tread 1 is connected to the reserved holes 21 through load-bearing bolts. S4. Adjustment and calibration: The levelness and perpendicularity of the plate-shaped steel stair beam 2 are adjusted through the three-way adjustment device 3. S5. Tightening and locking: After the adjustment is completed, all bolts are tightened and anti-loosening nuts are installed.

[0033] Specifically, for S1. Prefabrication production: The unitary tread 1 and the plate-shaped steel stair beam 2 are prefabricated using high-precision steel molds 7 processed numerically. The surface roughness of the inner cavity of the mold is ≤Ra0.8 μm, and the key dimension tolerances are controlled within ±0.2 mm, such as the tread width of the tread and the groove depth of the steel stair beam. The UHPC material process: The ultra-high performance concrete (UHPC) consists of 12% silica fume, 2.5% steel fiber, 58% ultra-fine cement, and 27.5% quartz sand. After being injected into the mold through high-pressure mixing, it is cured by steam at a constant temperature of 80°C for 48 hours to achieve a compressive strength of ≥150 MPa and a flexural strength of ≥25 MPa. Structure forming: The L-shaped structure of the unitary tread 1 and the fair-faced finish layer 12 are integrally cast. The trough-shaped cross-section of the plate-shaped steel stair beam 2 is formed by laser cutting, and elastic shock pads 23 are embedded in the card slots 22 to ensure that the dimensional error of the prefabricated components is <0.3 mm and the surface finish reaches Sa2.5 level.

[0034] S2. Transportation: Prefabricated components are packaged in a lightweight and modular manner, with the total weight of a single run < 300 kg. They are loaded into the construction elevator 8 in batches and transported to each floor. Transportation optimization: The unitary stepped tread 1 is protected by a composite of honeycomb cardboard and EPS foam, with the impact resistance meeting the ISTA3A standard; the plate-type steel ladder beam 2 is stacked layer by layer through a magnetic fixing bracket, increasing the single-transport volume by 50%, avoiding dependence on tower cranes, adapting to the narrow hoistways of high-rise buildings, and the minimum hoistway size is 1.5 m × 1.8 m.

[0035] S3. On-site assembly: The plate-type steel ladder beam 2 is initially fixed to the building support platform 4 through a three-way adjustment device 3, and the three-way adjustment device 3 is used to adjust the accuracy, forming an adjustment range of ±50 mm. Bolt connection and sealing: The load-bearing bolts at the bottom of the unitary stepped tread 1 are inserted into the reserved holes 21 of the steel ladder beam, and the gap between the bolts and the holes 21 of ±0.5 mm is filled with epoxy resin glue. After curing, the shear strength is ≥80 kN, and the sealing performance reaches the IP67 level, eliminating the hidden danger of water seepage.

[0036] S4. Adjustment and calibration: The motor of the three-way adjustment device 3 is driven through a handheld remote control, and the laser positioning unit feeds back the coordinate data to the terminal control system in real time, automatically generating adjustment instructions: Horizontal calibration: The lateral screw finely adjusts the deviation of the plate-type steel ladder beam 2 on the X-axis, with an accuracy of ±1 mm; Vertical calibration: The vertical bolts synchronously correct the elevation error of the Z-axis, with an accuracy of ±0.5 mm; Dynamic monitoring: The system displays the adjustment progress in real time, and the positioning of a single-run staircase is completed within 20 minutes.

[0037] S5. Tightening and locking: After the adjustment is completed, use a torque wrench 29 to tighten all bolts according to the standard of 50 N·m ± 5%, and install self-locking anti-loosening nuts.

[0038] In S3, a laser positioning unit is used to assist in the alignment and installation of the unitary stepped tread 1 and the plate-type steel ladder beam 2. The laser positioning unit feeds back the installation position deviation data to the terminal control system in real time, achieving millimeter-level precision adjustment; In S3, epoxy resin glue is filled between the load-bearing bolts and the reserved holes 21 to enhance the shear strength and sealing performance of the connection nodes.

[0039] Specifically, in S3, a laser positioning unit is used to assist in the alignment and installation of the unitized tread 1 and the plate - type steel ladder beam 2. This laser positioning unit can emit multiple laser beams to form a spatial positioning reference plane, real - time capture the relative position data of the unitized tread 1 and the plate - type steel ladder beam 2, and feedback the installation position deviation data to the terminal control system in millisecond - level speed. The control system automatically calculates the deviation compensation amount through algorithms and dynamically corrects the positions of the unitized tread 1 or the plate - type steel ladder beam 2 synchronously, thus achieving millimeter - level precision adjustment. This not only greatly improves the accuracy of alignment during installation but also significantly enhances the installation efficiency, reduces the time waste caused by repeated adjustments, and ensures that the overall linearity and levelness of the stair structure meet the design standards after installation.

[0040] In S3, epoxy resin glue is filled between the bearing bolts and the reserved holes 21. The epoxy resin glue has high - strength bonding performance and good fluidity. During the filling process, it can fully infiltrate the surfaces of the bearing bolts and the reserved holes 21, and form a firm bonding layer after curing. On the one hand, it can effectively enhance the shear strength of the connection node, make the load transfer between the bearing bolts and the plate - type steel ladder beam 2 more uniform, and avoid the stress concentration phenomenon that may occur in simple bolt connections, thereby improving the load - bearing capacity and anti - fatigue performance of the entire stair structure. On the other hand, the sealing layer formed after the epoxy resin glue cures can effectively prevent moisture, air, and other corrosive media from infiltrating into the connection node, prevent the bolts and steel ladder beam from rusting, and then improve the durability and service life of the stair structure, ensuring the reliability and stability of the connection node during the long - term use of the prefabricated stairs.

[0041] In S4, the adjustment process of the three - way adjustment device 3 is realized through an electric drive mechanism, and the operator controls the adjustment direction and amplitude through a hand - held remote control. After S5 is completed, a protective coating is sprayed on the surface of the unitized tread 1 to improve the wear resistance and anti - pollution performance.

[0042] Specifically, in S4, the operator sends command signals through a hand - held remote control. After being received by the wireless transmission module, it drives the electric drive mechanism to drive the plate - type steel ladder beam 2 to move in the preset direction and amplitude, meeting the strict requirements of the prefabricated building for the installation accuracy of the node, especially suitable for rapid positioning and calibration during the installation of high - rise building stairs.

[0043] After the completion of S5, a protective coating is sprayed on the surface of the modular step 1. The coating is composed of a composite of silica, fluorocarbon resin, and wear-resistant filler. After spraying, a transparent protective film with a thickness of about 50-100 μm can be formed on the step surface. The filler is filled in the micropores on the surface of UHPC, reducing the surface roughness by 30%-50%, forming a molecular-level dense protective layer, and significantly improving the impact resistance. On the other hand, the fluorocarbon group endows the surface with low surface energy characteristics, making the water contact angle > 110°, realizing the lotus effect, making it difficult for stains to adhere, and only a damp cloth needs to be wiped for daily cleaning, greatly reducing the maintenance cost. In addition, the coating is transparent and colorless, will not cover the natural texture of UHPC fair-faced concrete, and at the same time enhances the surface gloss, making the staircase both functional and decorative.

[0044] The specific synthesis method of the protective coating is as follows: Raw material preparation: Take 10%-15% of nano-silica, 50%-60% of fluorocarbon resin, and 20%-30% of ceramic microspheres by mass ratio. Additionally, prepare ethanol / acetone solvent, accounting for 20%-30% of the total system, and 0.5%-1% of silane coupling agent.

[0045] Dispersion and mixing: Add nano-silica into the solvent and ultrasonically disperse for 30 minutes until there is no agglomeration. Then, sequentially add fluorocarbon resin, wear-resistant filler, and coupling agent, and mechanically stir for 2 hours to form a homogeneous sol.

[0046] Coating and curing: Uniformly spray the sol on the surface of the UHPC step 1 through a high-pressure spraying device with a thickness of 50-100 μm. After standing at room temperature for 1 hour, cure it in an oven at 60-80 °C for 2 hours to form a transparent wear-resistant protective layer.

[0047] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A UHPC prefabricated precast staircase structure, characterized in that, Including: Unit type treads (1), plate - type steel ladder beams (2) and three - way adjustment devices (3); Load - bearing bolts are pre - embedded at the bottom of the unit type treads (1), and reserved holes (21) matching the load - bearing bolts are provided on the plate - type steel ladder beams (2); The plate - type steel ladder beam (2) is connected to the building support platform (4) through a three - way adjustment device (3), and the three - way adjustment device (3) allows the steel ladder beam (2) to be freely adjusted in the front - back, left - right, and up - down directions.

2. The UHPC prefabricated staircase structure according to claim 1, wherein, The unit type treads (1) are of an L - shaped structure, and a fair - faced concrete finish layer is integrally cast on its surface, and the single - point bearing capacity is greater than 1 ton.

3. The UHPC prefabricated staircase structure according to claim 1, characterized in that, The plate - type steel ladder beam (2) is a channel steel beam, and a card slot matching the bottom of the unit type treads (1) is provided on its inner side, and an elastic shock - absorbing gasket is filled in the card slot.

4. A UHPC assembled precast staircase structure according to claim 1, characterized in that, The three - way adjustment device (3) includes a lateral adjustment screw, a longitudinal adjustment screw and a vertical adjustment bolt, and each adjustment component is connected through a universal joint to achieve three - dimensional space fine - tuning.

5. The UHPC prefabricated staircase structure according to claim 1, wherein, The unit type treads (1) are made of ultra - high performance concrete (UHPC) material, and the total weight of a single - flight staircase is less than 300 kg.

6. A construction method for a UHPC assembled precast staircase structure, characterized in that, Applied to a UHPC prefabricated precast staircase structure according to any one of claims 1 - 5, the following steps are included: S1. Prefabrication production: Pour the unit type treads (1) and the plate - type steel ladder beams (2) using high - precision steel molds; S2. Transportation: Transport the prefabricated components to the construction site in batches through a construction elevator; S3. On - site assembly: Fix the plate - type steel ladder beam (2) to the support platform (4) through a three - way adjustment device (3), and then connect the unit type treads (1) to the reserved holes (21) through load - bearing bolts; S4. Adjustment and calibration: Adjust the levelness and perpendicularity of the plate - type steel ladder beam (2) through the three - way adjustment device (3); S5. Tightening and locking: After the adjustment is completed, tighten all bolts and install anti - loosening nuts.

7. The construction method of a UHPC assembled precast staircase structure according to claim 6, characterized in that, In S3, a laser positioning unit is used to assist in the alignment and installation of the unit type treads (1) and the plate - type steel ladder beam (2), and the laser positioning unit real - time feeds back the installation position deviation data to the terminal control system to achieve millimeter - level precision adjustment.

8. The construction method of a UHPC assembled precast staircase structure according to claim 6, characterized in that, In S3, epoxy resin glue is filled between the load - bearing bolts and the reserved holes (21) to enhance the shear strength and sealing performance of the connection nodes.

9. The construction method of a UHPC assembled precast staircase structure according to claim 6, characterized in that, In S4, the adjustment process of the three - way adjustment device (3) is realized through an electric drive mechanism, and the operator controls the adjustment direction and amplitude through a hand - held remote control.

10. The construction method of a UHPC assembled precast staircase structure according to claim 6, characterized in that, After S5 is completed, a protective coating is sprayed on the surface of the unit type treads (1) to improve the wear resistance and anti - pollution performance.

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