A prefabricated staircase connection structure and construction method

Abstract

This invention discloses a precast staircase connection structure and construction method. The precast staircase connection structure includes platform sections at both ends of the precast staircase, with platform grooves on each platform section. The composite stair beam includes a concave composite bottom beam and a cast-in-place connecting section. The top surface of the concave composite bottom beam has a bottom beam groove, and the cast-in-place connecting section is located within the platform groove and the bottom beam groove. The concave composite bottom beam and the cast-in-place connecting section, together with the platform sections of the precast staircase, form an integral stair beam, providing support. The connection nodes exhibit excellent overall performance, high safety and reliability, and facilitate the installation of precast concrete staircases, improving the prefabrication level and efficiency of building structures. It transforms the cast-in-place structure into precast component units, facilitating processing in component factories. T-shaped steel plate embedded parts can be used, reducing the amount of wet concrete casting work and lowering the difficulty of connection work. Furthermore, T-shaped steel plate embedded parts are more suitable for standardized factory production, which is beneficial for the quality control of precast components.

Description

Technical Field

[0001] This invention relates to the field of prefabricated building structure connection technology, specifically a prefabricated staircase connection structure and construction method. Background Technology

[0002] In recent years, prefabricated concrete structures have been widely used in the field of housing construction. They play a major role in China's building industrialization because they effectively improve building quality and construction efficiency; save materials, conserve energy and reduce emissions, save labor and improve working conditions; shorten construction period and facilitate winter construction.

[0003] In precast concrete components, the vertical connection of precast concrete stairs is one of the key technologies. The connection nodes of precast concrete components are the weakest link in precast concrete structures. The stair beams in precast concrete stair components are the key to the connection. Mature and reliable node connection technology is the key to ensuring the integrity and safety of precast concrete structures. Superior precast concrete component connection technology should simultaneously have the characteristics of safe and reliable connection, easy and convenient precast production, transportation and construction, and low cost. This is also the development direction of efficient connection of precast concrete components.

[0004] Currently, the most common connection method for prefabricated concrete staircases is bolted hinged connection. Bolted hinged connections have the advantages of convenient construction and wide application range. However, bolted hinged connections require moving the original structural beams back and changing them to L-shaped beams, altering the original structural design, increasing the width of the beams, and increasing the risk of overturning. Furthermore, in the event of a fire, the bolts in bolted hinged connections are easily exposed to high-temperature air, causing deformation and loss of load-bearing capacity, thus leading to an accident. Summary of the Invention

[0005] The purpose of this invention is to provide a prefabricated staircase connection structure and construction method, which combines the connection principle of composite structures and post-casting method to achieve excellent comprehensive performance.

[0006] In a first aspect, the present invention provides a prefabricated staircase connection structure, including a prefabricated staircase and a composite staircase beam. The prefabricated staircase is provided with a platform section and a platform groove. The composite staircase beam includes a concave composite bottom beam and a cast-in-place connecting section. The concave composite bottom beam is provided with a bottom beam groove. The cast-in-place connecting section is located in the platform groove and the bottom beam groove. The concave composite bottom beam and the cast-in-place connecting section together with the platform section of the prefabricated staircase constitute a complete staircase beam.

[0007] Furthermore, the concave composite bottom beam and the cast-in-place connection section form an integral stair beam with the platform section of the precast staircase via T-shaped steel plates. The T-shaped steel plates include the connecting lateral flanges on both sides and the vertical web.

[0008] Furthermore, the T-shaped steel plate includes a first T-shaped steel plate and a second T-shaped steel plate. The first T-shaped steel plate is a regular T-shaped plate, and the second T-shaped steel plate is an inverted T-shaped plate. The webs of the two are connected and both are connected to the cast-in-place connection section. The flange of the first T-shaped steel plate is connected to the platform section, and the flange of the second T-shaped steel plate is connected to the concave composite bottom beam.

[0009] Furthermore, there is a horizontal joint between the concave composite bottom beam and the bottom of the platform section of the precast staircase, and the horizontal joint is filled with cement mortar. The grooves of the bottom beam and the platform are also filled with cement mortar.

[0010] Furthermore, the precast staircase has a pre-reserved notch, and the cast-in-place rest platform of the floor slab is equipped with steps. The notch overlaps with the steps, and there is a gap between the side of the notch and the side of the steps of the cast-in-place rest platform of the floor slab. A waterproof sealing layer is installed in the gap.

[0011] Secondly, the present invention provides a construction method for a prefabricated staircase connection structure, comprising the following steps:

[0012] Step S01: The composite ladder beam is split into a concave composite bottom beam and a cast-in-place connection section;

[0013] Step S02: Set the bottom beam groove for the concave composite bottom beam, and set the platform groove for the platform section of the prefabricated staircase;

[0014] Step S03: The cast-in-place connection section is constructed in the platform groove and the bottom beam groove, and the concave composite bottom beam and the cast-in-place connection section are combined with the platform section of the precast staircase to form a whole stair beam.

[0015] Furthermore, in step S03, the concave composite bottom beam and the cast-in-place connecting section are connected to the platform section of the precast staircase via T-shaped steel plates to form an integral stair beam. The T-shaped steel plates include the connecting lateral flanges on both sides and the vertical web.

[0016] Furthermore, in step S03, the T-shaped steel plate includes a first T-shaped steel plate and a second T-shaped steel plate. The first T-shaped steel plate is a regular T-shaped plate, and the second T-shaped steel plate is an inverted T-shaped plate. The webs of the two are connected together and both are connected to the cast-in-place connection section. The flange of the first T-shaped steel plate is connected to the platform section, and the flange of the second T-shaped steel plate is connected to the concave composite bottom beam.

[0017] Furthermore, in step S01, a notch is reserved in the prefabricated staircase, and steps are set on the cast-in-place rest platform of the floor slab. The notch is then fitted and overlapped at the steps. A waterproof structure is laid at the bottom of the notch, and a gap is left between the side of the notch and the side of the steps of the cast-in-place rest platform of the floor slab.

[0018] Furthermore, in step S03, cement mortar is poured into the grooves of the bottom beam and the platform, and a waterproof sealing layer is installed in the gaps to achieve node connection.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. The prefabricated staircase connection structure of the present invention has excellent comprehensive performance of connection nodes, good safety and reliability, facilitates the installation of prefabricated concrete stairs, and improves the prefabrication level of building structures.

[0021] 2. The construction method of the precast staircase connection structure of the present invention transforms the cast-in-place structure into precast component units, which is convenient for component factories to process.

[0022] 3. The prefabricated staircase connection structure and construction method of the present invention can use T-shaped steel plate embedded parts, which not only reduces the amount of wet concrete pouring work, but also reduces the difficulty of connection work; and T-shaped steel plate embedded parts are more suitable for standardized factory production, which is conducive to the quality control of prefabricated components. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a single prefabricated staircase according to an embodiment of the present invention;

[0024] Figure 2 This is a cross-sectional structural diagram of a prefabricated staircase assembly installation according to an embodiment of the present invention;

[0025] Figure 3 This is a structural schematic diagram of a T-shaped steel plate unit according to an embodiment of the present invention.

[0026] Figure 4 for Figure 1 A cross-sectional structural diagram of the prefabricated staircase section;

[0027] Figure 5 for Figure 1 Schematic diagram of the cross-sectional structure of the composite bottom beam section;

[0028] Figure 6 for Figure 2 Enlarged view of a portion of point A in the middle;

[0029] Figure 7 for Figure 2 Enlarged view of section B in the middle.

[0030] In the diagram: 1-1 is the first T-shaped steel plate, 1-2 is the first through-reinforcement hole, 2-1 is the second T-shaped steel plate, 2-2 is the second through-reinforcement hole, 3 is the precast staircase, 301 is the platform section, 302 is the platform groove, 303 is the notched corner, 304 is the asphalt felt layer, 305 is the cement mortar leveling layer, 306 is the polystyrene filling layer, 307 is the inserted PE rod, 308 is the injected sealing adhesive layer, 4 is the concave composite bottom beam, 401 is the cast-in-place connection section, 402 is the bottom beam groove, 5 is the first longitudinal load-bearing fixing reinforcement, 6 is the second longitudinal load-bearing fixing reinforcement, 7 is the stirrup, 8 is the longitudinal structural reinforcement, 9 is the cement mortar, 10 is the longitudinal connecting reinforcement, and 11 is the cast-in-place rest platform of the floor slab. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0032] Reference Figure 1 A prefabricated staircase connection structure includes a prefabricated staircase 3 and a composite stair beam. The prefabricated staircase 3 is provided with a platform section 301, and the platform section 301 is provided with a platform groove 302; see reference. Figure 2 The composite stair beam includes a concave composite bottom beam 4 and a cast-in-place connecting section 401. The concave composite bottom beam 4 is provided with a bottom beam groove 402. The cast-in-place connecting section 401 is located in the platform groove 302 and the bottom beam groove 402. The concave composite bottom beam 4 and the cast-in-place connecting section 401 together with the platform section 301 of the precast stair 3 form an integral stair beam.

[0033] The traditional connection between precast staircase 3 and composite stair beam involves moving the rectangular composite stair beam a certain distance away from the platform section 301 of the precast staircase 3, changing the rectangular composite stair beam into an L-shaped stair beam. This increases the width of the stair beam, resulting in a reduction in stairwell space, an increased risk of head bumps, and a higher risk of excessive lateral bending moment and torque, leading to an increased risk of overturning. Furthermore, the traditional bolted hinged connection between the precast staircase 3 and the composite stair beam exposes the bolts directly to high-temperature air during a fire, causing deformation and loss of load-bearing capacity, potentially leading to accidents. This embodiment of the precast staircase connection structure, based on the safety requirements of precast concrete staircase structures and ease of construction, utilizes a composite structure. Without altering the position, structure, or dimensions of the composite stair beam, the rectangular composite stair beam is divided into a concave composite bottom beam 4 and a rectangular cast-in-place connection section 401, which are then connected to the platform section 301 of the precast staircase 3 to form a unified structure, jointly fulfilling the load-bearing function of the composite stair beam.

[0034] The prefabricated staircase connection structure in this embodiment, compared with the traditional composite stair beam pre-embedded bolt connection structure, can eliminate the need for formwork support, rebar tying, concrete pouring and other processes, reduce on-site operations and improve construction efficiency.

[0035] This could be a precast reinforced concrete staircase (staircase 3). The composite stair beam has a rectangular cross-section. (Refer to...) Figure 3 The platform groove 302 is a rectangular groove. (Refer to...) Figure 4 The bottom beam groove 402 is a rectangular groove.

[0036] Reference Figure 6In other embodiments, the cross section of the cast-in-place connection section 401 is cross-shaped, with the middle transverse portion forming a platform plate.

[0037] In other embodiments, the upper part of the cast-in-place connection section 401 is located in the platform groove 302, and the lower part is located in the bottom beam groove 402.

[0038] In some embodiments, the concave composite bottom beam 4 and the cast-in-place connecting section 401 form an integral stair beam with the platform section 301 of the precast staircase 3 via a T-shaped steel plate, referring to... Figure 3 T-shaped steel plates include connecting transverse flanges on both sides and a vertical web.

[0039] Reference Figure 6 In some embodiments, the T-shaped steel plate includes a first T-shaped steel plate 1-1 and a second T-shaped steel plate 2-1. The first T-shaped steel plate 1-1 is a regular T-shape, and the second T-shaped steel plate 2-1 is an inverted T-shape. The webs of the two are connected and both are connected to the cast-in-place connection section 401. The flange of the first T-shaped steel plate 1-1 is connected to the platform section 301, and the flange of the second T-shaped steel plate 2-1 is connected to the concave composite bottom beam 4.

[0040] In this embodiment, the prefabricated staircase connection structure divides the rectangular composite stair beam into a concave composite bottom beam 4 and a rectangular cast-in-place connection section 401, which are then connected to the platform section 301 of the prefabricated staircase 3 through a first T-shaped steel plate 1-1 and a second T-shaped steel plate 2-1 to form a whole, so as to jointly play the load-bearing role of the composite stair beam structure.

[0041] In other embodiments, the height H1 of the concave composite bottom beam 4 is equal to the height of the composite ladder beam - 180mm.

[0042] In other embodiments, the height H3 of the cast-in-place connecting section 401 = the height H4 of the concave composite bottom beam 4 + the height H5 of the platform groove 302 ≥ 180mm. That is, H3 = H4 + H5 ≥ 180mm.

[0043] Reference Figure 5 In other embodiments, the width L1 of the bottom beam groove 402 is 0.6 × the width L of the concave composite bottom beam 4.

[0044] In other embodiments, the bottom beam groove 402 is located at the central axis of the concave composite bottom beam 4.

[0045] In other embodiments, the width L2 of the protrusions on both sides of the bottom beam groove 402 is 0.2 × the width L of the concave composite bottom beam 4.

[0046] Reference Figure 4 In some other embodiments, the first T-shaped steel plate 1-1 is embedded in the central axis of the platform groove 302.

[0047] Reference Figure 3In other embodiments, the flange of the first T-shaped steel plate 1-1 is provided with a first through-beam hole 1-2, as shown in the figure. Figure 4 The platform section 301 of the precast staircase 3 is provided with a first longitudinal load-bearing fixing steel bar 5, which is inserted into the first through-bar hole 1-2.

[0048] In other embodiments, the first longitudinally stressed fixing steel bar 5 is located inside the top of the platform segment 301.

[0049] Reference Figure 2 In other embodiments, the bottom beam groove 402 is located directly below the platform groove 302.

[0050] In other embodiments, the bottom beam groove 402 and the platform groove 302 have the same dimensions.

[0051] Reference Figure 5 In other embodiments, the second T-shaped steel plate 2-1 is embedded in the central axis of the concave composite bottom beam 4. The concave composite bottom beam 4 is provided with longitudinal structural steel bars 8 and stirrups 7. The stirrups 7 surround the outside of the longitudinal structural steel bars 8. The number of the second T-shaped steel plate 2-1 and the stirrups 7 are both at least two, and they are arranged at intervals.

[0052] In other embodiments, the longitudinal structural steel bars 8 are disposed inside the top of the concave composite bottom beam 4.

[0053] In other embodiments, the stirrups 7 are rectangular rings. Rounded chamfers are provided at the corners of the stirrups 7. There are at least four longitudinal structural reinforcing bars 8, arranged in a rectangular pattern.

[0054] In other embodiments, the flange of the second T-shaped steel plate 2-1 is provided with a second through-bar hole 2-2, and a second longitudinal load-bearing fixing bar 6 is provided in the concave composite bottom beam 4, and the second longitudinal load-bearing fixing bar 6 passes through the second through-bar hole 2-2.

[0055] In other embodiments, the second longitudinally stressed fixing steel bar 6 is located inside the bottom of the concave composite bottom beam 4.

[0056] In other embodiments, the number of first T-shaped steel plates 1-1 and second T-shaped steel plates 2-1 are equal.

[0057] In other embodiments, at least three first fixing through holes 1-2 are reserved at the transverse central axis of the wing plate of the first T-shaped steel plate 1-1, and at least three second fixing through holes 2-2 are reserved at the transverse central axis of the wing plate of the second T-shaped steel plate 2-1.

[0058] In other embodiments, the inner diameter of the first fixing through hole 1-2 is greater than the outer diameter of the first longitudinally stressed fixing steel bar 5, and the inner diameter of the second fixing through hole 2-2 is greater than the outer diameter of the second longitudinally stressed fixing steel bar 6.

[0059] Reference Figure 3 In other embodiments, the depth of the first fixed through-beam hole 1-2 and the second fixed through-beam hole 2-2 on the flange of the first T-shaped steel plate 1-1 and the second T-shaped steel plate 2-1 is greater than or equal to the width L of the concave composite bottom beam 4, and the depth of the first fixed through-beam hole 1-2 and the second fixed through-beam hole 2-2 is greater than or equal to 15 × the outer diameter of the longitudinal connecting steel bar 10.

[0060] The lateral width of the left wing plate = the lateral width of the right wing plate = 2 × the lateral width of the web plate.

[0061] Reference Figure 6 In some other embodiments, the web of the first T-shaped steel plate 1-1 is provided with a first fixing through hole 1-2, and the web of the second T-shaped steel plate 2-1 is provided with a second fixing through hole 2-2. The longitudinal connecting steel bar 10 is inserted into the first fixing through hole 1-2 and the second fixing through hole 2-2 on the web of both.

[0062] In other embodiments, at least two first fixing through holes 1-2 are reserved on the web of the first T-shaped steel plate 1-1, and at least two second fixing through holes 2-2 are reserved on the web of the second T-shaped steel plate 2-1.

[0063] In other embodiments, the inner diameter of the first fixing through hole 1-2 and the second fixing through hole 2-2 on the web of the first T-shaped steel plate 1-1 and the second T-shaped steel plate 2-1 is greater than the outer diameter of the longitudinal connecting steel bar 10.

[0064] In other embodiments, the depth of the first fixed through-bar hole 1-2 and the second fixed through-bar hole 2-2 on the web of the first T-shaped steel plate 1-1 and the second T-shaped steel plate 2-1 is 0.2 ≥ 3 × the outer diameter of the longitudinal connecting steel bar 10.

[0065] In other embodiments, the outer diameter of the longitudinal connecting steel bar 10 is greater than or equal to the outer diameter of the second longitudinal force-bearing fixing steel bar 6.

[0066] In other embodiments, the thickness of the first T-shaped steel plate 1-1 is equal to the thickness of the second T-shaped steel plate 2-1, which is greater than or equal to the outer diameter of the stirrup 7.

[0067] In other embodiments, the material and strength grade of the first T-shaped steel plate 1-1 and the second T-shaped steel plate 2-1 are equivalent to the material and strength of the stirrup 7.

[0068] In other embodiments, concrete pads are placed on the protrusions on both sides of the bottom beam groove 402. The thickness of the concrete pads can be 20 mm.

[0069] Reference Figure 6In some embodiments, there is a horizontal joint between the concave composite bottom beam 4 and the bottom of the platform section 301 of the prefabricated staircase 3. The thickness of the horizontal joint can be 20mm, and the horizontal joint is filled with cement mortar 9. The bottom beam groove 402 and the platform groove 302 are filled with cement mortar 9.

[0070] Reference Figure 2 In some embodiments, the prefabricated staircase 3 has a notch 303, and the cast-in-place rest platform 11 of the floor slab is provided with steps. The notch 303 overlaps with the steps, and there is a gap between the side of the notch 303 and the side of the steps of the cast-in-place rest platform 11 of the floor slab. The gap width can be 20mm, and a waterproof sealing layer is provided in the gap to realize the node connection.

[0071] In some other embodiments, the notch 303 is square. The notch 303 is located at the lower end of the prefabricated staircase 3.

[0072] Reference Figure 7 In other embodiments, a waterproof structure is laid at the bottom of the notch 303. The waterproof structure includes an asphalt felt layer 304. The waterproof structure may also include a cement mortar leveling layer 305.

[0073] In other embodiments, the side length of the missing corner 303 is h1 + h2, where h1 is the thickness from the bottom of the corresponding cast-in-place connection section 401 platform plate to the bottom edge of the missing corner 303, h1 ≥ thickness of the cast-in-place connection section 401 platform plate / 2, and h2 is the thickness of the waterproof structure, which can be 20mm.

[0074] In other embodiments, the total thickness of the platform section 302 of the precast staircase 3 is = h1 + h2 + h3 + h4, where h3 is the thickness from the top of the platform slab of the corresponding cast-in-place connection section 401 to the top of the waterproof structure, and h4 is the surface layer thickness of the platform slab of the cast-in-place connection section 401.

[0075] In other embodiments, the waterproof sealing layer includes a filled polystyrene layer 306. The waterproof sealing layer may also include an inserted PE rod 307. The waterproof sealing layer may also include an injected sealing adhesive layer 308. Example

[0076] A construction method for a prefabricated staircase connection structure, used to implement the prefabricated staircase connection structure described in any one of Embodiments 1, includes the following steps:

[0077] Step S01: The composite ladder beam is split into a concave composite bottom beam 4 and a cast-in-place connection section 401;

[0078] Step S02: Set the bottom beam groove 402 on the concave composite bottom beam 4, and set the platform groove 302 on the platform section 301 of the prefabricated staircase 3;

[0079] Step S03: The cast-in-place connection section 401 is constructed in the platform groove 302 and the bottom beam groove 402, and the concave composite bottom beam 4 and the cast-in-place connection section 401 are combined with the platform section 301 of the precast staircase 3 to form a whole stair beam.

[0080] In some embodiments, in step S03, the concave composite bottom beam 4 and the cast-in-place connecting section 401 are connected to the platform section 301 of the precast staircase 3 by a T-shaped steel plate to form an integral stair beam. The T-shaped steel plate includes wing plates on both sides of the horizontal axis and a vertical web plate connected to each other.

[0081] In some embodiments, in step S03, the T-shaped steel plate includes a first T-shaped steel plate 1-1 and a second T-shaped steel plate 2-1. The first T-shaped steel plate 1-1 is a regular T-shape, and the second T-shaped steel plate 2-1 is an inverted T-shape. The webs of the two are connected together and both are connected to the cast-in-place connection section 401. The flange of the first T-shaped steel plate 1-1 is connected to the platform section 301, and the flange of the second T-shaped steel plate 2-1 is connected to the concave composite bottom beam 4.

[0082] In some embodiments, in step S01, a notch 303 is reserved in the prefabricated staircase 3, steps are set in the cast-in-place rest platform 11, and the notch 303 is fitted and overlapped at the steps; a waterproof structure is laid at the bottom of the notch 303, and a gap is left between the side of the notch 303 and the side of the steps of the cast-in-place rest platform 11.

[0083] In some embodiments, in step S03, cement mortar 9 is poured into the bottom beam groove 402 and the platform groove 302 to set a waterproof sealing layer in the gap, thereby realizing the node connection.

[0084] In some other embodiments, in step S01, a steel pad is provided on the side of the notched corner 303, and the steel pad is located between the side of the notched corner 303 and the side of the step; the horizontal width of the steel pad can be 20mm to ensure that the distance between the side of the notched corner 303 and the side of the step of the cast-in-place rest platform 11 is 20mm.

[0085] The construction method for the precast staircase connection structure provided in this invention can overcome the shortcomings and defects of existing bolted hinge connections for precast concrete staircases. Based on the principle of overlapping connection and the post-casting method combining embedded T-shaped steel plates and connecting steel bars, T-shaped steel plates that replace part of the stirrup function are pre-embedded at intervals during the casting of the precast staircase 3, and rectangular cross-section grooves are reserved. The rectangular overlapping stair beam is divided into a concave overlapping bottom beam 4 and a rectangular cast-in-place connection section 401. Corresponding T-shaped steel plates can be pre-embedded inside the concave overlapping bottom beam 4. After the precast staircase 3 is hoisted into place, the T-shaped steel plates pre-embedded in the concave overlapping bottom beam 4 of the rectangular overlapping stair beam are aligned and the connecting through holes on the T-shaped steel plates are aligned and then steel bars are inserted for fixation. High-strength cement mortar 9 is poured into the reserved bottom beam groove 402 and platform groove 302 to complete the node connection.

[0086] In actual construction, the construction method for the prefabricated staircase connection structure provided in this embodiment of the invention can more specifically include the following steps:

[0087] Step 1: Design of the breakdown of precast concrete staircase components;

[0088] Taking into account the architectural construction drawings and structural loads, and in accordance with the "Code for Design of Prefabricated Concrete Structures", the cast-in-place reinforced concrete staircase is broken down and further designed, and detailed design drawings of the prefabricated structure are drawn (such as...). Figure 2 This involves determining the plan construction drawings for each precast concrete staircase component and beam, transforming the cast-in-place structure into individual precast components for easier processing by the component factory.

[0089] Step 2: Determining the relevant properties of the concave composite bottom beam 4;

[0090] The height H1 of the concave composite bottom beam 4 is equal to the height of the composite ladder beam - 180mm.

[0091] The height H3 of the cast-in-place connection section 401 = the height H4 of the concave composite bottom beam 4 + the height H5 of the platform groove 302 ≥ 180mm. That is, H3 = H4 + H5 ≥ 180mm.

[0092] The width L1 of the groove 402 in the bottom beam is 0.6 × the width L of the concave composite bottom beam 4.

[0093] The bottom beam groove 402 is located at the central axis of the concave composite bottom beam 4.

[0094] The width of the protrusions on both sides of the groove 402 of the bottom beam is L2 = 0.2 × the width L of the concave composite bottom beam 4.

[0095] Step 3: Determining the connection nodes of the precast concrete staircase;

[0096] The precast staircase component 3 consists of stair sections and platform sections 301 at both ends. Compared to traditional precast staircases, the precast concrete staircase component in this embodiment precasts a portion of the staircase platform slab as the platform section 301, reducing on-site wet construction work such as formwork support, rebar tying, and concrete pouring, thus improving construction efficiency. Corresponding to the reserved rectangular bottom beam groove 402 position of the concave composite bottom beam 4 in step two, a rectangular platform groove 302 of the same size is reserved in the platform section 302 of the precast staircase component 3.

[0097] The first T-shaped steel plate 1-1 is pre-embedded in the central axis of the platform groove 302. The first through-bar hole 1-2 is reserved in the wing plate of the first T-shaped steel plate 1-1. The first longitudinal load-bearing fixing bar 5 is set in the platform section 301 of the prefabricated staircase 3 and the first longitudinal load-bearing fixing bar 5 is inserted into the first through-bar hole 1-2.

[0098] The second T-shaped steel plate 2-1 is pre-embedded at the center axis of the concave composite bottom beam 4. The concave composite bottom beam 4 is provided with longitudinal structural steel bars 8 and stirrups 7. The stirrups 7 surround the outside of the longitudinal structural steel bars 8. The number of the second T-shaped steel plate 2-1 and the stirrups 7 are both at least two, and they are arranged at intervals.

[0099] The flange of the second T-shaped steel plate 2-1 is pre-drilled with a second through-bar hole 2-2. A second longitudinal load-bearing fixing bar 6 is installed in the concave composite bottom beam 4, and the second longitudinal load-bearing fixing bar 6 is inserted into the second through-bar hole 2-2. The number of the first T-shaped steel plate 1-1 and the second T-shaped steel plate 2-1 are equal.

[0100] Three first fixing through holes 1-2 are reserved at the transverse centerline of the wing plate of the first T-shaped steel plate 1-1, and three second fixing through holes 2-2 are reserved at the transverse centerline of the wing plate of the second T-shaped steel plate 2-1.

[0101] A first fixed through-bar hole 1-2 is provided on the web of the first T-shaped steel plate 1-1, and a second fixed through-bar hole 2-2 is provided on the web of the second T-shaped steel plate 2-1. The longitudinal connecting steel bar 10 is inserted into the first fixed through-bar hole 1-2 and the second fixed through-bar hole 2-2 on the webs of both plates.

[0102] Two first fixing through holes 1-2 are reserved on the web of the first T-shaped steel plate 1-1, and two second fixing through holes 2-2 are reserved on the web of the second T-shaped steel plate 2-1.

[0103] The precast staircase 3 has a notch 303, and the cast-in-place rest platform 11 of the floor slab is set with steps. The notch 303 overlaps with the steps. There is a gap between the side of the notch 303 and the side of the steps of the cast-in-place rest platform 11 of the floor slab. The gap width can be 20mm. A waterproof sealing layer is set in the gap to realize the node connection.

[0104] A waterproof structure is laid at the bottom of the missing corner 303. The waterproof structure includes an asphalt felt layer 304. The waterproof structure may also include a cement mortar leveling layer 305.

[0105] Make the side length of the missing corner 303 = h1 + h2, where h1 is the thickness from the bottom of the corresponding cast-in-place connection section 401 platform plate to the bottom edge of the missing corner 303, h1 ≥ thickness of cast-in-place connection section 401 platform plate / 2, and h2 is the thickness of the waterproof structure, which can be 20mm.

[0106] The total thickness of the platform section 302 of the precast staircase 3 is equal to h1 + h2 + h3 + h4, where h3 is the thickness from the top of the platform slab of the corresponding cast-in-place connection section 401 to the top of the waterproof structure, and h4 is the surface layer thickness of the platform slab of the cast-in-place connection section 401.

[0107] Step 4: Determining the relevant properties of the T-shaped steel plate embedded parts;

[0108] T-shaped steel plates consist of two connected transverse flanges and a vertical web.

[0109] The T-shaped steel plate includes a first T-shaped steel plate 1-1 and a second T-shaped steel plate 2-1. The first T-shaped steel plate 1-1 is a regular T-shape, and the second T-shaped steel plate 2-1 is an inverted T-shape. The webs of the two are connected and both are connected to the cast-in-place connection section 401. The flange of the first T-shaped steel plate 1-1 is connected to the platform section 301, and the flange of the second T-shaped steel plate 2-1 is connected to the concave composite bottom beam 4.

[0110] The inner diameter of the first fixing through hole 1-2 is greater than the outer diameter of the first longitudinally stressed fixing steel bar 5, and the inner diameter of the second fixing through hole 2-2 is greater than the outer diameter of the second longitudinally stressed fixing steel bar 6.

[0111] The inner diameter of the first fixed through-bar hole 1-2 and the second fixed through-bar hole 2-2 on the web of the first T-shaped steel plate 1-1 and the second T-shaped steel plate 2-1 is greater than the outer diameter of the longitudinal connecting steel bar 10.

[0112] The depth of the first fixed through-bar hole 1-2 and the second fixed through-bar hole 2-2 on the web of the first T-shaped steel plate 1-1 and the second T-shaped steel plate 2-1 is 0.2 ≥ 3 × the outer diameter of the longitudinal connecting steel bar 10.

[0113] The outer diameter of the longitudinal connecting steel bar 10 is greater than or equal to the outer diameter of the second longitudinal load-bearing fixing steel bar 6.

[0114] The thickness of the first T-shaped steel plate 1-1 = the thickness of the second T-shaped steel plate 2-1 ≥ the outer diameter of the stirrup 7.

[0115] The material and strength grade of the first T-shaped steel plate 1-1 and the second T-shaped steel plate 2-1 are made to be the same as the material and strength of the stirrup 7.

[0116] Step 5: Casting and prefabrication of precast concrete components;

[0117] Based on the detailed fabrication drawings of the precast staircase 3 components, determine the dimensions and positions of the rectangular platform groove 302 and the square notch 303 reserved in the platform section 301, as well as the embedded position, dimensions, and model of the first T-shaped steel plate 1-1. Based on the detailed fabrication drawings of the concave composite bottom beam 4, determine the dimensions and positions of the rectangular bottom beam groove 402 reserved, as well as the embedded position, dimensions, and model of the second T-shaped steel plate 2-1. Arrange the steel reinforcement skeleton for the precast staircase 3 components and the concave composite bottom beam 4, wherein the first longitudinal load-bearing fixing steel bar 5 of the precast staircase 3 and the second longitudinal load-bearing fixing steel bar 6 at the bottom of the concave composite bottom beam 4 are respectively inserted into the first fixing through hole 1-2 and the second fixing through hole 2-2 and tied together, so that the first longitudinal load-bearing fixing steel bar 5 of the precast staircase 3 and the second longitudinal load-bearing fixing steel bar 6 at the bottom of the concave composite bottom beam 4 form an effective whole with the first fixing through hole 1-2 and the second fixing through hole 2-2 respectively. Then, assemble the molds for the precast staircase 3 components and the concave composite bottom beam 4, and pour the concrete for the precast components.

[0118] Step Six: Curing and demolding inspection of precast concrete components;

[0119] Steam curing was applied to the precast staircase component 3 and the concave composite bottom beam component 4 after the concrete was poured. After the initial setting of the concrete, the foam protective components on the exposed parts of the first T-shaped steel plate 1-1 and the second T-shaped steel plate 2-1 were removed in a timely manner, and anti-corrosion treatment was performed on them. After curing, the molds of the precast staircase component 3 and the concave composite bottom beam component 4 were removed, and the surface, dimensions, embedded parts of the first T-shaped steel plate 1-1 and the second T-shaped steel plate 2-1, and the integrity of the reserved rectangular bottom beam groove 402 and the square notch 303 of the precast staircase component 3 and the concave composite bottom beam component 4 were inspected. Protective facilities were installed, and then all the precast concrete components were transported to the site in sequence according to the transportation plan.

[0120] Step 7: Hoisting and Installation of Precast Concrete Components

[0121] After the components arrive on site, they are inspected again for size, integrity and damage. The exposed parts of the first T-shaped steel plate 1-1 and the second T-shaped steel plate 2-1 and the reinforcing bars are straightened to ensure that the first fixed through holes 1-2 and the second fixed through holes 2-2 of the web of the first T-shaped steel plate 1-1 and the second T-shaped steel plate 2-1 of the precast staircase 3 component and the concave composite bottom beam 4 component are precisely aligned.

[0122] First, measurements and layout are conducted to determine the installation position of the concave composite bottom beam 4 components. Then, the components are hoisted into place and supported for fixation. After the installation of each set (each set can consist of two) of the concave composite bottom beam 4 components is completed, the hoisting and installation of the corresponding precast staircase 3 components begins. First, 20mm thick concrete pads are placed on the upper part of the protrusions on both sides of the concave composite bottom beam 4 components. A layer of asphalt felt 304 and a cement mortar leveling layer 305 are laid at the bottom of the corresponding missing corner 303 of the cast-in-place rest platform slab 11 and the platform section 301 of the precast staircase 3 components, forming a waterproof structure to enhance the waterproofing effect. The total thickness of the waterproof structure is h2. 20mm thick strip steel pads are placed on the side of the missing corner 303 to ensure a 20mm distance between the edges of the cast-in-place rest platform slab 11 and the platform slab of the precast staircase 3 components. Then, the precast staircase 3 component is hoisted and installed to the designated position, ensuring that the first fixing through holes 1-2 and 2-2 of the web of the first T-shaped steel plate 1-1 and the second T-shaped steel plate 2-1 of the precast staircase 3 component and the concave composite bottom beam 4 component are precisely aligned. The longitudinal connecting steel bars 10 are inserted into the first fixing through holes 1-2 and 2-2 of the web of the first T-shaped steel plate 1-1 and the second T-shaped steel plate 2-1, and the two ends are tied and fixed. The length of the longitudinal connecting steel bars 10 is equal to the length of the concave composite bottom beam 4. The 20mm thick transverse joint between the upper part of the two protrusions of the concave composite bottom beam 4 component and the bottom of the platform section 301 of the precast staircase 3 component is sealed. Then, high-strength cement mortar 9 is poured into the platform groove 302 and the bottom beam groove 402 of the precast staircase 3 component and the concave composite bottom beam 4 component. Remove the strip steel pads placed on the sides of the cast-in-place rest platform slab 11 and the platform section 301 of the precast staircase 3 component, and the corresponding missing corner 303. Fill the gap with polystyrene from bottom to top, insert PE rods, and finally seal with glue. This will make the bottom vertical side seam form a polystyrene filling layer 306, an inserted PE rod 307, and an injected sealing glue 308 from top to bottom, thus completing the node connection.

[0123] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0124] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A prefabricated staircase connection structure, comprising a prefabricated staircase and composite stair beams, wherein the prefabricated staircase is provided with a platform section, characterized in that, The platform section is provided with a platform groove; the composite stair beam includes a concave composite bottom beam and a cast-in-place connecting section. The concave composite bottom beam is provided with a bottom beam groove, and the cast-in-place connecting section is located in the platform groove and the bottom beam groove. The concave composite bottom beam and the cast-in-place connecting section together with the platform section of the precast staircase form an integral stair beam; the upper part of the cast-in-place connecting section is located in the platform groove, and the lower part is located in the bottom beam groove. The concave composite bottom beam and the cast-in-place connecting section are connected to the platform section of the precast staircase via T-shaped steel plates to form an integral stair beam. The T-shaped steel plate includes connecting lateral flanges on both sides and a vertical web. The T-shaped steel plate includes a first T-shaped steel plate and a second T-shaped steel plate. The first T-shaped steel plate is a regular T-shape, and the second T-shaped steel plate is an inverted T-shape. The webs of the two are connected and both are connected to the cast-in-place connecting section. The flanges of the first T-shaped steel plate are connected to the platform section, and the flanges of the second T-shaped steel plate are connected to the concave composite bottom beam. The prefabricated staircase has a pre-reserved corner, and the cast-in-place rest platform of the floor slab is provided with steps. The corner overlaps with the steps, and there is a gap between the side of the corner and the side of the steps of the cast-in-place rest platform of the floor slab. A waterproof sealing layer is provided in the gap; a waterproof structure is laid at the bottom of the corner.

2. The prefabricated staircase connection structure according to claim 1, characterized in that, There is a horizontal joint between the concave composite bottom beam and the bottom of the platform section of the precast staircase, and the horizontal joint is filled with cement mortar. The grooves of the bottom beam and the platform are also filled with cement mortar.

3. The construction method for the prefabricated staircase connection structure according to claim 1 or 2, characterized in that, Includes the following steps: Step S01: The composite ladder beam is split into the concave composite bottom beam and the cast-in-place connection section; Step S02: Set a bottom beam groove for the concave composite bottom beam, and set a platform groove for the platform section of the prefabricated staircase; Step S03: The cast-in-place connection section is constructed in the platform groove and the bottom beam groove, and the concave composite bottom beam and the cast-in-place connection section together with the platform section of the precast staircase form a whole stair beam.

4. The construction method of the prefabricated staircase connection structure according to claim 3, characterized in that, In step S03, the concave composite bottom beam and the cast-in-place connecting section are connected to the platform section of the precast staircase via T-shaped steel plates to form an integral stair beam. The T-shaped steel plate includes lateral flanges on both sides and a vertical web plate that are connected to each other.

5. The construction method of the prefabricated staircase connection structure according to claim 4, characterized in that, In step S03, the T-shaped steel plate includes a first T-shaped steel plate and a second T-shaped steel plate. The first T-shaped steel plate is a regular T-shaped plate, and the second T-shaped steel plate is an inverted T-shaped plate. The webs of the two plates are connected together and both are connected to the cast-in-place connection section. The flange of the first T-shaped steel plate is connected to the platform section, and the flange of the second T-shaped steel plate is connected to the concave composite bottom beam.

6. The construction method of the prefabricated staircase connection structure according to claim 4, characterized in that, In step S01, a notch is reserved in the prefabricated staircase, and steps are set on the cast-in-place rest platform of the floor slab. The notch is fitted and overlapped at the steps. A waterproof structure is laid at the bottom of the notch, and a gap is left between the side of the notch and the side of the steps of the cast-in-place rest platform of the floor slab.

7. The construction method of the prefabricated staircase connection structure according to claim 6, characterized in that, In step S03, cement mortar is poured into the grooves of the bottom beam and the platform, and a waterproof sealing layer is installed in the gap to achieve node connection.

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