Local prestress support-free prefabricated floor system and construction method thereof

Abstract

The invention relates to a local pre-stress support-free prefabricated floor system and a construction method thereof. The support-free prefabricated floor system comprises stand columns and a bearing frame beam, wherein a first embedded part is embedded in the end face of the bearing frame beam, and a bearing steel corbel is further arranged on the side face of the bearing frame beam; the prestressed frame beams and the prestressed secondary beams are provided with prestressed tendons, and second embedded parts are embedded in the end faces of the prestressed frame beams; and a laminated slab; the construction method comprises the following steps that S1, the stand columns are arranged in an array; s2, the bearing frame beam is hoisted to the position between the left stand column and the right stand column which are adjacent; s3, the prestressed frame beam is hoisted to the position between the two front-back adjacent stand columns; s4, the pre-stress secondary beams are hoisted to the position between the two bearing frame beams which are adjacent front and back; S5, the laminated slabs are hoisted to the position between the pre-stress secondary beams or the position between the pre-stress frame beams and the pre-stress secondary beams; and S6, concrete is poured. The pre-stress technology is introduced into part of components, and the anti-shearing pieces are arranged at the ends of the bearing frame beams, so that the feasibility of the local pre-stress support-free prefabricated floor system is guaranteed.

Description

Technical Field

[0001] The invention relates to the field of prefabricated buildings, in particular to a locally prestressed support-free prefabricated floor slab and a construction method thereof. Background Art

[0002] There are already many multi-faceted designs for the application scenarios of unsupported floors, but there are few design solutions for large-span unsupported floors at this stage.

[0003] The span of the unsupported floor disclosed in CN117027498A, CN118481288A, etc. is about 12 meters. At present, some relevant owners have proposed the demand for unsupported prefabricated floor with a span of 20-25 meters. The longer span will cause excessive deflection and cracks in the prefabricated beams during the construction process.

[0004] Therefore, how to design a prefabricated floor slab without support that has a span of 20-25 meters is a technical difficulty that needs to be solved at present. Summary of the invention

[0005] The purpose of the present invention is to provide a locally prestressed support-free prefabricated floor and a construction method thereof, which ensures the feasibility of a large-span support-free prefabricated floor by introducing prestressing technology into some components and arranging heavy-duty shear-resistant connectors at the ends of supporting frame beams.

[0006] The present invention is implemented by the following technical solution: a local prestressed support-free prefabricated floor slab, comprising

[0007] The columns are reinforced concrete structures and are distributed in an array. The left and / or right sides of the top of any column are provided with a first steel corbel, the front and / or rear sides of the top of any column are provided with a second steel corbel, and the top surface of the column is provided with a column reinforcement extending upward;

[0008] The supporting frame beam is a reinforced concrete structure formed by pouring concrete with a plurality of first open hoops and first beam bottom bars, and is arranged on a first steel corbel between any two adjacent columns on the left and right; a plurality of first open hoops are arranged in sequence and a plurality of first beam bottom bars are connected side by side to the bottom of the first open hoops; a first beam groove extending to both ends of the supporting frame beam is provided at the top of the supporting frame beam, the upper end of the first open hoop extends out of the top of the supporting frame beam, and both ends of the first beam bottom bar extend out of the end face of the supporting frame beam; a first embedded part is embedded in the end face of the supporting frame beam, and a supporting steel corbel is also provided on the front and / or rear side of the supporting frame beam;

[0009] The prestressed frame beam is a reinforced concrete structure formed by pouring concrete with a plurality of second open hoops and a second beam bottom reinforcement, and is arranged on a second steel corbel between any two adjacent front and rear columns; a plurality of second open hoops are arranged in sequence and a plurality of second beam bottom reinforcements are connected side by side to the bottom of the second open hoops; a second beam groove extending to both ends of the prestressed frame beam is provided at the top of the prestressed frame beam, an upper end of the second open hoop extends out of the top of the prestressed frame beam, and both ends of the second beam bottom reinforcement extend out of the end face of the prestressed frame beam; a second embedded part is embedded in the end face of the precast beam;

[0010] The upper end surface of the prestressed frame beam is a first inclined surface, a first pipe is also pre-buried in the prestressed frame beam, and a first prestressed tendon that is arc-shaped and slightly bent downward is arranged in the first pipe, and the anchor end and the tensioning end of the first prestressed tendon are respectively arranged on the two first inclined surfaces of the prestressed frame beam, and the anchor end and the tensioning end of the first prestressed tendon are perpendicular to the corresponding first inclined surfaces;

[0011] The prestressed secondary beam is a reinforced concrete structure formed by pouring concrete with a plurality of third open hoops and a third beam bottom reinforcement, and is arranged on a supporting steel corbel between any two adjacent supporting frame beams; a plurality of third open hoops are arranged in sequence and a plurality of third beam bottom reinforcements are connected side by side to the bottom of the third open hoops; the upper end of the third open hoops extends out of the top of the prestressed secondary beam, and an embedded steel member is embedded in the end face of the prestressed secondary beam, the outer end of the embedded steel member extends out of the end face of the prestressed secondary beam and is connected to the third beam bottom reinforcement at the inner end of the embedded steel member;

[0012] The middle and upper parts of the end surface of the prestressed secondary beam are respectively the second inclined surface and the guide inclined surface, and the inclination of the guide inclined surface is greater than that of the second inclined surface; a second pipe is also embedded in the prestressed secondary beam, and a second prestressed tendon that is arc-shaped and slightly bent downward is arranged in the second pipe, and the anchorage end and the tensioning end of the second prestressed tendon are respectively arranged on the two second inclined surfaces of the prestressed secondary beam, and the anchorage end and the tensioning end of the second prestressed tendon are perpendicular to the corresponding second inclined surfaces;

[0013] The composite slab is a reinforced concrete structure, with steel bars extending from the edges on the left and right sides, and truss steel bars extending to the left and right on the surface;

[0014] The supporting frame beam is installed between two adjacent columns on the left and right, the prestressed frame beam is installed between two adjacent columns on the front and back, the prestressed secondary beam is installed between two adjacent columns on the left and right, and the embedded steel member is placed on the supporting steel corbel; the composite plate is laid between two adjacent prestressed secondary beams; and the columns, supporting frame beams, prestressed frame beams, prestressed secondary beams, the top surface of the composite plate and the nodes are poured with cast-in-place concrete layers.

[0015] A construction method for a partially prestressed brace-free prefabricated floor slab comprises the following steps:

[0016] S1, arranging the columns in an array;

[0017] S2, hoisting the supporting frame beam between two adjacent columns on the left and right, with the supporting frame beam supported on the first steel bracket of the column, and the first beam bottom reinforcement of the supporting frame beam extending into the column;

[0018] S3, hoisting the prestressed frame beam between two front and rear adjacent columns, and the prestressed frame beam is supported on the second steel bracket of the column, and the second beam bottom reinforcement of the prestressed frame beam extends into the column;

[0019] S4, hoisting the prestressed secondary beam between two adjacent supporting frame beams, and the prestressed secondary beam is supported on the supporting steel brackets of the supporting frame beams.

[0020] S5, hoisting the composite slab between two adjacent prestressed secondary beams or between a prestressed frame beam and a prestressed secondary beam, and extending the steel bars to above the prestressed frame beam and the prestressed secondary beam;

[0021] S6, cast-in-place concrete is poured on the supporting frame beams, prestressed frame beams, prestressed secondary beams, composite slabs, column top surfaces and corresponding nodes.

[0022] Compared with the previous technology, the beneficial effects of the present invention are:

[0023] 1. The prestressed components such as the prestressed frame beams and prestressed secondary beams of the present invention are installed in a non-prestressed structure composed of columns and supporting frame beams to form a large-span local prestressed support-free prefabricated floor slab. The construction sequence is basically the same as that of the traditional support-free prefabricated floor slab, and the transportation cost is low, the installation difficulty is small, and the characteristics of no support and no formwork are retained during the construction process.

[0024] 2. Since prestress is only applied to local prefabricated components, the construction cost is reduced compared to the cast-in-place solution that applies prestress to all components. At the same time, since the prestress of the local prestressed components is applied before installation, it will not produce adverse tension on other areas of the floor slab, and the crack resistance of the floor slab is significantly better than the cast-in-place floor slab with local prestress.

[0025] 3. The increase in the span of the floor leads to an increase in the shear force transmission at the connection nodes between the supporting frame beam and the column and at the connection nodes between the supporting frame beam and the prefabricated secondary beam. The present invention innovatively embeds a first embedded part as a shear-resistant part at the end of the supporting frame beam and arranges an embedded steel member at the end of the prefabricated secondary beam, which greatly improves the shear resistance at the node and ensures the safety and feasibility of the locally prestressed support-free prefabricated floor.

[0026] 4. Due to the protruding anchors at the ends of the prestressed components, the existing prefabricated primary and secondary beam nodes cannot meet the installation requirements. By prefabricated prestressed secondary beam ends embedded steel components and the shape combination of the second slope and the guide slope of the prefabricated secondary beam end face, the prefabricated prestressed secondary beam can be reliably connected to the supporting frame beam, and the construction quality of the post-cast concrete in the node area can be guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure supporting the frame beam;

[0028] Figure 2 is a structural schematic diagram of the first embedded part;

[0029] Figure 3 It is a schematic diagram of the structure supporting the steel corbel;

[0030] Figure 4 This is a structural diagram of the supporting steel corbel from another perspective;

[0031] Figure 5 It is a structural schematic diagram of a prestressed frame beam;

[0032] Figure 6 is a schematic structural diagram of a second embedded part;

[0033] Figure 7 is a schematic diagram of the structure of the first prestressed tendon;

[0034] Figure 8 is a structural schematic diagram of the end portion of the first prestressed tendon;

[0035] Fig. 9 It is the structural schematic diagram of the prestressed secondary beam;

[0036] Fig.10 It is a structural schematic diagram of the embedded steel components;

[0037] Fig.11 It is a structural schematic diagram of the composite plate;

[0038] Fig.12 A schematic diagram of completing step 1 of the present invention;

[0039] Fig.13 A schematic diagram of completing step 2 of the present invention;

[0040] Fig.14 This is a schematic diagram of completing steps 3 and 4 of the present invention;

[0041] Fig.15 This is an enlarged view of the connection between the prestressed secondary beam and the supporting frame beam in step 3;

[0042] Fig.16 It is a schematic diagram of completing step 5 of the present invention.

[0043] Explanation of reference numbers: 1-column, 11-first steel corbel, 12-second steel corbel, 13-column reinforcement, 2-supporting frame beam, 21-first opening hoop, 22-first beam bottom reinforcement, 23-first beam groove, 24-first embedded part, 241-first outer rib, 242-first inner rib, 243-first embedded steel plate, 244-first anchor bar, 245-first avoidance gap, 25-supporting steel corbel, 251-supporting embedded steel plate, 252-supporting outer cross plate, 253-supporting outer bottom plate, 254-supporting outer side plate, 255-supporting inner rib, 256-supporting anchor bar, 3-prestressed frame beam, 31-second opening hoop , 32-second beam bottom reinforcement, 33-second beam groove, 34-second embedded part, 341-second outer rib, 342-second inner rib, 343-second embedded steel plate, 344-second anchor bar, 345-second avoidance gap, 35-first inclined plane, 36-first prestressed bar, 4-prestressed secondary beam, 41-third opening hoop, 42-third beam bottom reinforcement, 43-embedded steel member, 431 third embedded steel plate, 432 steel bottom plate, 433 stud, 44-second inclined plane, 45-guide inclined plane, 46-second prestressed bar, 5-composite plate, 51-extension steel bar, 52-truss steel bar, 61-sealing plate, 62-spiral bar. DETAILED DESCRIPTION

[0044] The present invention is described in detail below in conjunction with the accompanying drawings:

[0045] like Figure 1-5 As shown: 1. A local prestressed support-free prefabricated floor, comprising

[0046] The columns 1 are reinforced concrete structures and are arranged in an array. The left and / or right sides of the top of any column 1 are provided with a first steel corbel 11, the front and / or rear sides of the top of any column 1 are provided with a second steel corbel 12, and the top surface of the column 1 is provided with a column reinforcement 13 extending upward;

[0047] The supporting frame beam 2 is a reinforced concrete structure formed by pouring concrete with a plurality of first open hoops 21 and first beam bottom bars 22, and is arranged on the first steel corbel 11 between any two adjacent columns 1 on the left and right; a plurality of first open hoops 21 are arranged in sequence and a plurality of first beam bottom bars 22 are connected side by side to the bottom of the first open hoops 21; a first beam groove 23 extending to both ends of the supporting frame beam 2 is provided at the top of the supporting frame beam 2, the upper end of the first open hoop 21 extends out of the top of the supporting frame beam 2, and both ends of the first beam bottom bars 22 extend out of the end face of the supporting frame beam 2; a first embedded part 24 is embedded in the end face of the supporting frame beam 2, and a supporting steel corbel 25 is also provided on the front and / or rear side of the supporting frame beam 2;

[0048] The prestressed frame beam 3 is a reinforced concrete structure formed by pouring concrete with a plurality of second open hoops 31 and a second beam bottom rib 32, and is arranged on the second steel corbel 12 between any two adjacent front and rear columns 1; a plurality of second open hoops 31 are arranged in sequence and a plurality of second beam bottom ribs 32 are connected side by side to the bottom of the second open hoops 31; a second beam groove 33 extending to both ends of the prestressed frame beam 3 is provided at the top of the prestressed frame beam 3, the upper end of the second open hoop 31 extends out of the top of the prestressed frame beam 3, and both ends of the second beam bottom rib 32 extend out of the end face of the prestressed frame beam 3; a second embedded part 34 is embedded in the end face of the precast beam;

[0049] The upper end surface of the prestressed frame beam 3 is a first inclined surface 35. A first pipe is also pre-buried in the prestressed frame beam 3 and a first prestressed tendon 36 is arranged in the first pipe. The first prestressed tendon 36 is arc-shaped and slightly bent downward. The anchor end and the tension end of the first prestressed tendon 36 are respectively arranged on the two first inclined surfaces 35 of the prestressed frame beam 3, and the anchor end and the tension end of the first prestressed tendon 36 are perpendicular to the corresponding first inclined surfaces 35.

[0050] The prestressed secondary beam 4 is a reinforced concrete structure formed by pouring concrete with a plurality of third open hoops 41 and third beam bottom bars 42, and is arranged on a supporting steel corbel 25 between any two adjacent supporting frame beams 2; a plurality of third open hoops 41 are arranged in sequence and a plurality of third beam bottom bars 42 are connected side by side to the bottom of the third open hoops 41; the upper end of the third open hoops 41 extends out of the top of the prestressed secondary beam 4, and an embedded steel member 43 is embedded in the end face of the prestressed secondary beam 4, the outer end of the embedded steel member 43 extends out of the end face of the prestressed secondary beam 4 and the inner end of the embedded steel member 43 is connected to the third beam bottom bar 42;

[0051] The middle and upper parts of the end surface of the prestressed secondary beam 4 are respectively a second inclined surface 44 and a flow guiding inclined surface 45, and the inclination of the flow guiding inclined surface 45 is greater than that of the second inclined surface 44; a second pipe is also pre-buried in the prestressed secondary beam 4, and a second prestressed tendon 46 which is arc-shaped and slightly bent downward is arranged in the second pipe, and the anchorage end and the tensioning end of the second prestressed tendon 46 are respectively arranged on the two second inclined surfaces 44 of the prestressed secondary beam 4, and the anchorage end and the tensioning end of the second prestressed tendon 46 are perpendicular to the corresponding second inclined surfaces 44;

[0052] The composite plate 5 is a reinforced concrete structure, with steel bars 51 extending from the edges on the left and right sides, and truss steel bars 52 extending left and right on the surface;

[0053] The supporting frame beam 2 is installed between two adjacent columns 1 on the left and right, the prestressed frame beam 3 is installed between two adjacent columns 1 on the front and back, the prestressed secondary beam 4 is installed between two adjacent columns 1 on the left and right, and the embedded steel member 43 is placed on the supporting steel corbel 25; the composite plate 5 is laid between two adjacent prestressed secondary beams 4; and the columns 1, supporting frame beams 2, prestressed frame beams 3, prestressed secondary beams 4, the top surfaces of the composite plates 5 and the nodes are cast with cast-in-place concrete layers.

[0054] The columns 1, supporting frame beams 2 and composite plates in the present invention are all conventional prefabricated components, and the main feature is that prestressed tendons are provided in the prestressed frame beams 3 and the prestressed secondary beams 4, and prestressed tensioning treatment is performed.

[0055] The prestressing method is divided into pre-tensioning method and post-tensioning method. The present invention has no specific restrictions on the prestressing method. Take the processing method of the prestressed frame beam 3 as an example: the first pipeline is pre-buried in the prestressed frame beam 3, and the first prestressed tendon is passed through the first pipeline. The first prestressed tendon is stretched to fix its two ends at the two ends of the prestressed frame beam 3. After that, due to the contraction of the first prestressed tendon, the concrete at the bottom of the prestressed frame beam 3 is compressed. The compressed concrete has better properties. On the one hand, the concrete is not easy to crack, and the prestressed frame beam 3 will be properly arched under the action of prestress, which can effectively control the deformation of the prestressed frame beam 3 in the unsupported state.

[0056] The present invention designs some components as prestressed components (prestressed frame beams 3, prestressed secondary beams 4), and installs the prestressed components into non-prestressed structures (i.e., columns 1 and supporting frame beams 2), thereby forming the locally prestressed support-free prefabricated floor slab.

[0057] In addition, compared with the main beam of the same position in the traditional unsupported floor, the supporting frame beam 2 of the present invention has an additional first embedded part 24 as a shear-resistant part on the end face. The main purpose of designing this structure is that since the span of the prestressed secondary beam 4 is increased compared with the traditional secondary beam, the total load in this area is increased, that is, the original area was only 100 m2, but the area may be increased to 200 m2 due to the increase in the span of the prestressed secondary beam 4, which will cause the load borne by the supporting frame beam 2 to be greatly increased, which will directly cause the shear force transmitted at the post-cast concrete node of the supporting frame beam 2 and the column 1 to increase exponentially.

[0058] In the background art, the main beams corresponding to the supporting frame beams 2 are all provided with keyways on the end faces, but the keyways are not suitable for such heavy-loaded beams. The first embedded parts 24 are used to improve the shear resistance.

[0059] It is also necessary to explain that the second prestressed tendons and the second embedded parts in the prestressed secondary beam 4 and the second prestressed tendons of the prestressed frame beam 3 have basically the same function. The main difference between the prestressed secondary beam 4 and the prestressed frame beam 3 is also reflected in the end face. The end face is divided into a second inclined surface 44 and a guide inclined surface 45 to form a three-fold line shape. The second inclined surface 44 and the first inclined surface have the same effect. Since the prestressed tendons are arc-shaped, it is necessary to ensure that the end face of the prestressed tendons and the second inclined surface or the first inclined surface are in a plumb state.

[0060] The design of the guide slope 45 takes into account the hoisting of the prestressed secondary beam 4. Generally, when the prestressed secondary beam 4 is hoisted to the supporting steel bracket, there needs to be a gap between it and the inner side of the supporting steel bracket (see Fig.15 ); In addition to reducing the difficulty of installation, the gap also needs to avoid the protruding part of the prestressed tendon anchor; so in order to facilitate subsequent pouring, a diversion slope is considered to be set up.

[0061] Here, the first embedded part 24 includes a first outer rib 241, a first inner rib 242, a first embedded steel plate 243 and a plurality of first anchor bars 244; the first outer rib 241 is placed horizontally and installed on the outer side surface of the first embedded steel plate 243, the first inner rib 242 is placed horizontally and on the inner side surface of the first embedded steel plate 243, a plurality of first anchor bars 244 are installed on the inner side surface of the first embedded steel plate 243, and a plurality of first avoidance gaps 245 are opened on the first outer rib 241.

[0062] The first avoidance gap 245 is provided here to ensure that the first embedded part 24 and the column reinforcement 13 of the column are avoided, and the combination of new and old concrete can be transmitted through the steel plate array, so that the shear bearing capacity is greatly improved.

[0063] The supporting steel corbel 25 includes a supporting embedded steel plate 251, a supporting outer transverse plate 252, a supporting outer bottom plate 253, a supporting outer side plate 254, a supporting inner rib plate 255, and a plurality of supporting anchor bars 256; the supporting outer transverse plate 252 is horizontally placed and installed on the outer side of the supporting embedded steel plate 251, the supporting outer bottom plate 253 is vertically arranged and located at the bottom of the supporting outer transverse plate 252, and the supporting outer side plate 254 is arranged on both sides of the supporting outer transverse plate 252; a plurality of supporting inner rib plates 255 are installed on the inner side of the supporting embedded steel plate 251, and a plurality of supporting anchor bars 256 are installed on the inner side of the supporting embedded steel plate 251. The supporting steel corbel 25 here mainly ensures strength to achieve support.

[0064] The second embedded part 34 includes a second outer rib 341, a second inner rib 342, a second embedded steel plate 343 and a plurality of second anchor bars 344; the second outer rib 341 is placed horizontally and installed on the outer side of the second embedded steel plate 343, the second inner rib 342 is placed horizontally and on the inner side of the second embedded steel plate 343, a plurality of second anchor bars 344 are installed on the inner side of the second embedded steel plate 343, and a plurality of second avoidance notches 345 are provided on the second outer rib 341. The second embedded part 34 has basically the same structure and effect as the first embedded part, so it will not be described in detail.

[0065] The embedded steel member 43 includes a third embedded steel plate 431, a steel bottom plate 432 and bolts 433; a plurality of groups of the third embedded steel plates 431 are distributed in parallel, the front bottom edges of the third embedded steel plates 431 are fixed on the steel bottom plate 432, and the facing surfaces of any two adjacent third embedded steel plates 431 are evenly provided with bolts 433; the rear edge of the steel bottom plate 432 is connected to the end of the third beam bottom reinforcement 42.

[0066] The anchorage end and tensioning end of the first prestressed tendon 36 and the anchorage end and tensioning end of the second prestressed tendon 46 include a fixed cover plate 61 and a spiral tendon 62 located inside the cover plate. This structure is also a conventional structure of prestressed tendons, so it will not be elaborated.

[0067] A construction method for a partially prestressed brace-free prefabricated floor slab comprises the following steps:

[0068] S1, arranging the columns 1 in an array;

[0069] S2, hoisting the supporting frame beam 2 between two adjacent columns 1, and the supporting frame beam 2 is supported on the first steel corbel 11 of the column 1, and the first beam bottom reinforcement 22 of the supporting frame beam 2 extends into the column 1;

[0070] S3, hoisting the prestressed frame beam 3 between two front and rear adjacent columns 1, and the prestressed frame beam 3 is supported on the second steel corbel 12 of the column 1, and the second beam bottom reinforcement 32 of the prestressed frame beam 3 extends into the column 1;

[0071] S4, hoist the prestressed secondary beam 4 between two adjacent supporting frame beams 2, and the prestressed secondary beam 4 is supported on the supporting steel bracket 25 of the supporting frame beam 2.

[0072] S5, hoisting the composite plate 5 between two adjacent prestressed secondary beams 4 or between the prestressed frame beam 3 and the prestressed secondary beam 4, and extending the steel bars 51 to the top of the prestressed frame beam 3 and the prestressed secondary beam 4;

[0073] S6, cast-in-place concrete is poured on the supporting frame beam 2, the prestressed frame beam 3, the prestressed secondary beam 4, the composite slab 5, the top surface of the column 1 and the corresponding nodes.

[0074] The hoisting sequence here is basically the same as the hoisting logic of traditional unsupported floor slabs.

[0075] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A local prestressed brace-free prefabricated floor, characterized in that: include The columns (1) are reinforced concrete structures and are arranged in an array. The left and / or right sides of the top of any column (1) are provided with a first steel bracket (11), the front and / or rear sides of the top of any column (1) are provided with a second steel bracket (12), and the top surface of the column (1) is provided with a column reinforcement (13) extending upwards; The supporting frame beam (2) is a reinforced concrete structure formed by pouring concrete with a plurality of first open hoops (21) and first beam bottom bars (22), and is arranged on a first steel corbel (11) between any two adjacent columns (1) on the left and right; the plurality of first open hoops (21) are arranged in sequence and a plurality of first beam bottom bars (22) are connected side by side to the bottom of the first open hoops (21); a first beam groove (23) extending toward both ends of the supporting frame beam (2) is provided at the top of the supporting frame beam (2); the upper end of the first open hoop (21) extends out of the top of the supporting frame beam (2), and both ends of the first beam bottom bars (22) extend out of the end face of the supporting frame beam (2); a first embedded part (24) is embedded in the end face of the supporting frame beam (2), and a supporting steel corbel (25) is further provided on the front and / or rear side of the supporting frame beam (2); The prestressed frame beam (3) is a reinforced concrete structure formed by pouring concrete with a plurality of second open hoops (31) and second beam bottom bars (32), and is arranged on a second steel corbel (12) between any two front and rear adjacent columns (1); the plurality of second open hoops (31) are arranged in sequence and a plurality of second beam bottom bars (32) are connected side by side to the bottom of the second open hoops (31); the top of the prestressed frame beam (3) is provided with a second beam groove (33) extending toward both ends of the prestressed frame beam (3); the upper end of the second open hoops (31) extends out of the top of the prestressed frame beam (3), and both ends of the second beam bottom bars (32) extend out of the end face of the prestressed frame beam (3); and the end face of the precast beam is embedded with a second embedded part (34); The upper end surface of the prestressed frame beam (3) is a first inclined surface (35), a first pipe is also pre-buried in the prestressed frame beam (3), and a first prestressed tendon (36) is arranged in the first pipe in an arc shape and slightly bent downward, the anchor end and the tensioning end of the first prestressed tendon (36) are respectively arranged on the two first inclined surfaces (35) of the prestressed frame beam (3), and the anchor end and the tensioning end of the first prestressed tendon (36) are perpendicular to the corresponding first inclined surfaces (35); The prestressed secondary beam (4) is a reinforced concrete structure formed by pouring concrete with a plurality of third open hoops (41) and third beam bottom bars (42), and is arranged on a supporting steel corbel (25) between any two adjacent supporting frame beams (2) in front and behind; the plurality of third open hoops (41) are arranged in sequence and a plurality of third beam bottom bars (42) are connected side by side to the bottom of the third open hoops (41); the upper end of the third open hoops (41) extends out of the top of the prestressed secondary beam (4), and an embedded steel member (43) is embedded in the end surface of the prestressed secondary beam (4), the outer end of the embedded steel member (43) extends out of the end surface of the prestressed secondary beam (4) and the inner end of the embedded steel member (43) is connected to the third beam bottom bar (42); The middle and upper parts of the end surface of the prestressed secondary beam (4) are respectively a second inclined surface (44) and a flow guiding inclined surface (45), and the inclination of the flow guiding inclined surface (45) is greater than that of the second inclined surface (44); a second pipe is also pre-buried in the prestressed secondary beam (4), and a second prestressed tendon (46) is provided in the second pipe in an arc shape and slightly bent downward, and the anchorage end and the tensioning end of the second prestressed tendon (46) are respectively arranged on the two second inclined surfaces (44) of the prestressed secondary beam (4), and the anchorage end and the tensioning end of the second prestressed tendon (46) are perpendicular to the corresponding second inclined surfaces (44); The composite plate (5) is a reinforced concrete structure, with steel bars (51) extending from the edges provided on the left and right sides, and truss steel bars (52) extending to the left and right on the surface; The supporting frame beam (2) is installed between two adjacent columns (1) on the left and right, the prestressed frame beam (3) is installed between two adjacent columns (1) on the front and back, the prestressed secondary beam (4) is installed between two adjacent columns (1) on the left and right, and the embedded steel member (43) is placed on the supporting steel bracket (25); the composite plate (5) is laid between two adjacent prestressed secondary beams (4); and the columns (1), the supporting frame beam (2), the prestressed frame beam (3), the prestressed secondary beam (4), the composite plate (5) and the top surfaces and nodes thereof are cast with cast-in-place concrete layers.

2. A locally prestressed brace-free prefabricated floor according to claim 1, characterized in that: The first embedded component (24) comprises a first outer rib (241), a first inner rib (242), a first embedded steel plate (243), and a plurality of first anchor bars (244); the first outer rib (241) is placed transversely and installed on the outer side surface of the first embedded steel plate (243), the first inner rib (242) is placed transversely and on the inner side surface of the first embedded steel plate (243), the plurality of first anchor bars (244) are installed on the inner side surface of the first embedded steel plate (243), and the first outer rib (241) is provided with a plurality of first avoidance notches (245).

3. The local prestressed support-free prefabricated floor according to claim 1, characterized in that: The supporting steel corbel (25) comprises a supporting embedded steel plate (251), a supporting outer transverse plate (252), a supporting outer bottom plate (253), a supporting outer side plate (254), a supporting inner rib plate (255), and a plurality of supporting anchor bars (256); the supporting outer transverse plate (252) is arranged horizontally and installed on the outer side surface of the supporting embedded steel plate (251); the supporting outer bottom plate (253) is arranged vertically and located at the bottom of the supporting outer transverse plate (252); the supporting outer side plate (254) is arranged on both sides of the supporting outer transverse plate (252); the plurality of supporting inner rib plates (255) are installed on the inner side surface of the supporting embedded steel plate (251); and the plurality of supporting anchor bars (256) are installed on the inner side surface of the supporting embedded steel plate (251).

4. The local prestressed brace-free prefabricated floor slab according to claim 1, characterized in that: The second embedded part (34) comprises a second outer rib (341), a second inner rib (342), a second embedded steel plate (343) and a plurality of second anchor bars (344); the second outer rib (341) is placed transversely and installed on the outer side surface of the second embedded steel plate (343), the second inner rib (342) is placed transversely and on the inner side surface of the second embedded steel plate (343), the plurality of second anchor bars (344) are installed on the inner side surface of the second embedded steel plate (343), and the second outer rib (341) is provided with a plurality of second avoidance notches (345).

5. The local prestressed support-free prefabricated floor according to claim 1, characterized in that: The embedded steel member (43) comprises a third embedded steel plate (431), a steel bottom plate (432) and bolts (433); a plurality of groups of the third embedded steel plates (431) are arranged in parallel, the front bottom edges of the third embedded steel plates (431) are fixed to the steel bottom plate (432), and the bolts (433) are evenly arranged on the facing surfaces of any two adjacent third embedded steel plates (431); and the rear edge of the steel bottom plate (432) is connected to the end of the third beam bottom reinforcement (42).

6. The local prestressed brace-free prefabricated floor slab according to claim 1, characterized in that: The anchorage end and the tensioning end of the first prestressed tendon (36) and the anchorage end and the tensioning end of the second prestressed tendon (46) comprise a fixed sealing plate (61) and a spiral tendon (62) located inside the sealing plate.

7. A construction method for a partially prestressed brace-free prefabricated floor according to any one of claims 1 to 6, characterized in that: The steps include: S1, arranging the columns (1) in an array; S2, hoisting the supporting frame beam (2) between two adjacent columns (1) on the left and right, with the supporting frame beam (2) supported on the first steel bracket (11) of the column (1), and the first beam bottom reinforcement (22) of the supporting frame beam (2) extending into the column (1); S3, hoisting the prestressed frame beam (3) between two front and rear adjacent columns (1), with the prestressed frame beam (3) supported on the second steel bracket (12) of the column (1), and the second beam bottom reinforcement (32) of the prestressed frame beam (3) extending into the column (1); S4, hoisting the prestressed secondary beam (4) between two front and rear adjacent supporting frame beams (2), and the prestressed secondary beam (4) is supported on the supporting steel brackets (25) of the supporting frame beams (2), S5, hoisting the composite plate (5) between two adjacent prestressed secondary beams (4) on the left and right, or between the prestressed frame beam (3) and the prestressed secondary beam (4), and extending the extension steel bars (51) to above the prestressed frame beam (3) and the prestressed secondary beam (4); S6, cast-in-place concrete is poured on the supporting frame beam (2), the prestressed frame beam (3), the prestressed secondary beam (4), the composite slab (5), the top surface of the column (1) and the corresponding nodes.

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