CN115538582A - Post-tensioned unbonded prefabricated prestressed concrete open-pore beam frame structure system connected by UHPC (ultra high performance concrete) and design and construction method thereof - Google Patents

Abstract

The invention discloses a post-tensioned unbonded prefabricated prestressed concrete open-pore beam frame structure system connected by UHPC (ultra high performance concrete), which comprises a prefabricated concrete upper column, a prefabricated concrete lower column, a post-tensioned unbonded prefabricated prestressed concrete open-pore composite beam, an UHPC (ultra high performance concrete) node core area and a composite plate. The upper longitudinal main reinforcement extends out of the bottom surface of the prefabricated upper column, the lower longitudinal main reinforcement extends out of the top surface of the prefabricated lower column, and the end face of the common reinforcement extending out of the prefabricated concrete beam is directly anchored in the core area of the UHPC node. This structural system not only site operation is convenient quick, improve component installation effectiveness, can reduce reinforcing bar anchor length by a wide margin in addition, reduce node core area stirrup quantity by a wide margin, it is crowded to avoid node core area reinforcing bar, can reduce the component cross-section height again, alleviate the dead weight, improve component anti-cracking performance, bearing capacity, unbonded prestressed tendon provides self-resuming ability for the structure, the wholeness and the structural toughness of reinforcing structure, thereby improve overall frame structure's anti-seismic performance, reduce the restoration cost after shaking.

Description

Post-tensioned unbonded prefabricated prestressed concrete open-pore beam frame structure system connected by UHPC (ultra high Performance concrete) and design and construction methods thereof

Technical Field

The invention relates to the technical field of prefabricated prestressed fabricated building construction, in particular to a UHPC (ultra high performance concrete) connected post-tensioned unbonded prefabricated prestressed concrete open-pore beam frame structure system and a design and construction method thereof.

Background

The cast-in-place structure has the limitations of low construction efficiency, high energy consumption and the like, and is gradually difficult to adapt to the development requirement of building industrialization. The prefabricated building has become the development direction of building industrialization due to the advantages of high construction speed, factory production of components, reduction of field wet operation, reduction of environmental pollution and the like. Through years of development and popularization, prefabricated concrete structures have been widely researched and used.

The prefabricated assembly type concrete frame structure is a structure that beam column components are prefabricated in a prefabrication factory and transported to a construction site to be connected to form an integral structure. Compared with a cast-in-place concrete structure, the cast-in-place concrete structure has the advantages of high construction speed, easy guarantee of component quality, good quality, small environmental pollution, labor cost saving, large quantity of templates and supports saving and the like, and has a very wide prospect. For a wet connection assembly type concrete frame structure, a node structure form which is easy to construct and effectively ensures integrity is the key for popularization and application. However, from the conventional earthquake disaster, the assembled structure is seriously damaged in the earthquake, and the same earthquake-proof performance as that of the cast-in-place structure is difficult to achieve. In order to improve the integrity and reliability of the joint connection of the prefabricated concrete frame and reach or even exceed the seismic performance of a cast-in-place concrete structure, a prestress technology and UHPC materials are introduced into the prefabricated structure.

The post-tensioned unbonded prestressed prefabricated concrete structure is a structure formed by splicing prefabricated parts together through tensioning prestressed tendons and has the characteristics of the post-tensioned unbonded prestressed concrete structure and the prefabricated structure. The internal stress generated by the prestress on the concrete section can partially or completely offset the section stress under the use load, delay the occurrence of cracks and improve the rigidity of the member. When unloading, the crack can be partially or completely closed, and the elastic recovery performance of the structure is good. Meanwhile, the prestressed concrete can make full use of the material strength of the prestressed tendons and the concrete, and the self weight of the structure is reduced. And the application of the prestress contributes to the improvement of the service performance and the integrity of the assembled structure, and promotes the application of the assembled structure in a large-span and heavy-load structure.

The UHPC has excellent bonding performance, and can greatly reduce the anchoring length of the steel bar and the prestressed tendon in the UHPC; the strength is high, the stirrup consumption in the node core area can be reduced, and the UHPC is used in the node core area, so that the structure is simple and the frame integrity is good. The pre-stressed structure has excellent stress performance, and the UHPC is applied to a node core area to form a pre-stressed frame structure. The structure is deeply researched, and the prefabricated prestressed concrete frame structure is favorable for further popularization and application.

Disclosure of Invention

The invention aims to provide a post-tensioned unbonded prefabricated prestressed concrete open-pore beam frame structure system connected by UHPC (ultra high Performance concrete) and a design and construction method thereof by combining the excellent performance of the UHPC, aiming at the defects in the prior art. The post-tensioned unbonded prestressed concrete frame structure combines three traditional structures, namely a post-tensioned unbonded prestressed structure, an assembled structure and a superposed structure, and adopts a UHPC high-performance material, so that the aim of improving the anti-seismic performance of the prefabricated assembled concrete frame structure is fulfilled.

The invention has the advantages that the invention mainly embodies the connection technology of the precast concrete beam column components and the steel bar connection technology between the components. In the aspect of component connection technology, beam column components are connected through UHPC with excellent performance to form a UHPC node core area, and the requirement of seismic fortification of strong node weak components is more easily realized, so that the ductility of beam column nodes is improved, and the seismic performance of the whole frame structure is improved. In the aspect of the steel bar connection technology, steel bars between beam column components only need to be simply lapped, and the lapping length is very small, so that the manufacturing time and the field installation time of prefabricated components are greatly saved. Therefore, the UHPC-connected post-tensioned unbonded prefabricated prestressed concrete open-pore beam frame structure system and the design and construction method thereof provided by the invention conform to the green development strategy of building industrialization in China.

The technical problem solved by the invention can be realized by adopting the following technical scheme:

a post-tensioned unbonded prefabricated prestressed concrete open-pore beam frame structure system connected by UHPC comprises a prefabricated concrete upper column, a prefabricated concrete lower column, a post-tensioned unbonded prefabricated prestressed concrete open-pore superposed beam, an UHPC node core area and a superposed slab;

the prefabricated concrete upper column is internally provided with an upper longitudinal main rib, the prefabricated concrete lower column is internally provided with a lower longitudinal main rib, the post-tensioned unbonded prefabricated prestressed concrete open-pore superposed beam is internally provided with a prefabricated concrete open-pore beam, a beam superposed layer and a post-tensioned unbonded prestressed rib, the bottom of the prefabricated concrete open-pore beam is provided with common reinforcing steel bars, and if necessary, the periphery of an orifice can also be provided with hanging ribs and reinforcing steel bar meshes, the reinforcing steel bar meshes can also adopt welded reinforcing steel bar meshes, the beam superposed layer is internally provided with a through long reinforcing steel bar at the top, and the superposed slab consists of a prefabricated concrete slab and a slab superposed layer poured on the slab;

the upper longitudinal main reinforcement extends out of the bottom surface of the prefabricated upper column and is directly anchored in the UHPC node core area, the lower longitudinal main reinforcement extends out of the top surface of the prefabricated lower column and is directly anchored in the UHPC node core area, and the common reinforcement extends out of the end surface of the prefabricated concrete open-hole beam and is directly anchored in the UHPC node core area;

the unbonded prestressed tendons comprise linear, broken line or curved prestressed tendons;

the post-tensioned unbonded precast prestressed concrete open-pore superposed beam is constructed and checked according to a force transmission mode matched with the common concrete open-pore simply supported beam and the support setting before a beam superposed layer, a plate superposed layer and a UHPC node core area are poured, after the node core area, the beam superposed layer and the plate superposed layer are poured, the strength of the node and the superposed layer concrete reaches the design requirement, the tensioning of unbonded prestressed ribs is carried out, after the tensioning is finished, the support is removed, and the construction stage checking is carried out according to the frame beam; the post-tensioned unbonded prefabricated prestressed concrete open-hole superposed beam has different sections of upper chords at the hole openings before the beam superposed layer, the plate superposed layer and the UHPC node core area are poured and different stress states, and the construction checking calculation is carried out on the upper chords and the lower chords at the hole openings of the prefabricated concrete open-hole beam; after the prestress is built, the construction checking calculation and the checking calculation of the normal use limit state of the unbonded prestressed tendon are calculated by using the effective prestress, and the stress increment is considered when the checking calculation of the bearing capacity limit state is carried out.

Furthermore, the post-tensioned unbonded precast prestressed concrete open-pore superposed beam consists of a precast concrete open-pore beam, a beam superposed layer and a post-tensioned unbonded prestressed tendon; the composite slab is composed of a precast concrete slab and a slab lamination layer poured on the slab.

Further, the post-tensioned unbonded prestressed tendons is pre-buried in the precast concrete trompil beam component to pass UHPC node core area and both ends and stretch out outside the UHPC node core area, its both ends are the fixed anchor clamps and the ground tackle of being provided with respectively, and one end setting is in the post outside, and one end sets up in the roof beam coincide layer.

Furthermore, the bottom surface of the precast concrete upper column, the top surface of the precast concrete lower column and the end surface of the post-tensioned unbonded precast prestressed concrete open-pore superposed beam are provided with sunken grooves.

Further, the precast concrete upper column is fixed at a corresponding position by a reliable support.

Furthermore, stirrups in the precast concrete upper column, the precast concrete lower column and the post-tensioned unbonded precast prestressed concrete open-hole superposed beam are divided into an encrypted area and a non-encrypted area, the stirrups in the core area of the UHPC node are arranged according to design requirements, the shear resistance of the core area is calculated according to an inclined compression bar and a truss model, steel fibers in the UHPC node are considered to be equivalent into a horizontal stirrup and a vertical longitudinal bar, the contribution of the horizontal stirrup and the vertical longitudinal bar to the shearing resistance of the core area of the node is considered, and the contribution of the unbonded prestressed bars to the shearing resistance of the node is considered.

Further, the precast concrete open-hole beam and the top surface of the precast concrete slab are provided with rough surface layers.

The invention also provides a design method of the system, which comprises the following steps:

step 1: the beam and the column are designed according to the existing standard and invention patent;

step 2: checking and calculating the strength of the upper chord and the lower chord at the opening of the precast concrete open-pore beam before pouring the beam superposed layer, the plate superposed layer and the UHPC node core area of the precast prestressed concrete open-pore superposed beam;

and step 3: the open hole position in the precast prestressed concrete open-hole composite beam is located in a midspan 1/3 section as far as possible, and when the open hole position is located in a beam end 1/3 section, the distance from the edge of the open hole close to the node to the inner edge of the node is larger than 1.5 times of the height of the beam.

A UHPC connected post-tensioned unbonded prefabricated prestressed concrete open-pore beam frame structure system comprises the following steps:

step 1: manufacturing a precast concrete lower column, a precast concrete upper column, a precast concrete open-hole beam and a precast concrete slab; wherein, enough anchoring length needs to be reserved in the core area of the anchoring node of the precast concrete lower column and the precast concrete upper column extending out of the longitudinal bar; enough anchoring length needs to be reserved in a core area of an anchoring node of a common steel bar extending out of the precast concrete perforated beam; pre-burying a prestressed tendon at a design position when a precast concrete open-hole beam is manufactured, and reserving enough length at two ends;

and 2, step: after the maintenance of the prefabricated part is finished, hoisting the prefabricated concrete lower column and installing the prefabricated concrete lower column on the foundation, and installing a sufficient number of stirrups on the longitudinal main reinforcement extending out of the lower column;

and 3, step 3: hoisting the precast concrete open-pore beam to the top surface of the precast concrete lower column, enabling the bottom surface of the precast concrete open-pore beam to be flush with the top surface of the precast concrete lower column, enabling the end part of the precast concrete open-pore beam to be placed on the precast concrete lower column, and fixing the precast concrete open-pore beam by using a support; common steel bars extending out of the precast concrete open pore beams on the two sides are reasonably avoided and directly anchored in the node core area according to the construction requirements;

and 4, step 4: hoisting the precast concrete upper column to be right above the precast concrete lower column, fixing the precast concrete upper column at a corresponding position by using a reliable support, and binding the stirrups and the column longitudinal bars installed in the step 2 together; wherein, the longitudinal bars extending out of the upper and lower precast concrete columns are reasonably avoided in the core area of the node and are directly anchored;

and 5: the top through long steel bar penetrates through a stirrup reserved in a beam overlapping layer area and a node core area and is bound, then prestressed tendons which are pre-embedded and extend out of a precast concrete open-hole beam are bound in the node core area according to a designed position, then a UHPC node core area is poured, and a template is arranged so that the UHPC cannot enter the beam overlapping layer;

step 6: after the core area of the UHPC node is maintained to be enough strength, hoisting the precast concrete flat plate (or the composite slab, the double T plate and the secondary beam) to the precast concrete beam and fixing;

and 7: pouring a beam laminated layer and a plate laminated layer;

and step 8: after the beam laminated layer and the plate laminated layer are maintained to have enough strength, tensioning the unbonded prestressed tendons;

and step 9: and repeating the manufacturing process to finish the post-tensioning unbonded prefabricated prestressed concrete open-pore beam frame structure system.

Compared with the prior art, the invention has the advantages that:

1. the prefabricated concrete structure and the post-tensioned unbonded prestressed structure are combined together, and the advantages of convenience and rapidness in construction, good construction quality, energy conservation and environmental friendliness of the prefabricated structure are utilized, so that the structure using performance can be improved, the height of the section of a component can be reduced, the self-weight is reduced, the anti-cracking performance and the self-recovery performance of the component are improved, and the anti-seismic performance of the whole frame structure is improved. The unbonded prestressed tendons provide self-resetting capability for the structure, the integrity and the structural toughness of the structure are enhanced, and the repair cost after the earthquake is reduced.

2. The UHPC material with excellent performance is adopted and applied to the node core area, so that the reliable connection of the prefabricated beam column member can be realized, the bearing capacity and the anti-seismic performance of the node can be improved, the anchoring length of the steel bars and the prestressed bars can be greatly reduced, and the stirrup dosage in the node core area can be obviously reduced, thereby avoiding the steel bar crowding in the node core area, and greatly improving the manufacturing, transporting and installing efficiency of the prefabricated beam column member.

Drawings

FIG. 1 is a schematic structural diagram of a framework structure system of a UHPC-based prefabricated prestressed concrete open-cell beam of the invention

FIG. 2 is a schematic view of reinforcement of a two-span frame structure

FIG. 3 is a schematic view of a two-span frame structure

FIG. 4 is a detailed view of the edge node structure of the middle layer frame of the present invention

FIG. 5 is an isometric view of an intermediate layer frame edge node of the present invention

FIG. 6 is a detailed view of the node structure in the middle layer frame of the present invention

FIG. 7 is an isometric view of a node in an intermediate layer frame of the present invention

Detailed Description

So that the manner in which the features, objects, and advantages of the invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.

As shown in fig. 1-7, the framework structure system of the UHPC-connected post-tensioned unbonded precast prestressed concrete open-pore beam comprises a precast concrete upper column (1), a precast concrete lower column (2), a post-tensioned unbonded precast prestressed concrete open-pore superposed beam (3), a UHPC node core area (4) and a laminated slab (17);

an upper longitudinal main rib (5) is arranged in the precast concrete upper column (1), a lower longitudinal main rib (6) is arranged in the precast concrete lower column (2), a precast concrete open pore beam (7), a beam laminated layer (8) and a post-tensioned unbonded prestressed rib (9) are arranged in the post-tensioned unbonded precast prestressed concrete open pore laminated beam (3), a common reinforcing steel bar (10) is arranged at the bottom of the precast concrete open pore beam (7), a top through long reinforcing steel bar (11) is arranged in the beam laminated layer (8), and the laminated slab (17) consists of a precast concrete slab (18) and a slab laminated layer (19) poured on the slab;

the upper longitudinal main rib (5) extends out of the bottom surface of the prefabricated upper column (1) and is directly anchored in the UHPC node core area (4), the lower longitudinal main rib (6) extends out of the top surface of the prefabricated lower column (2) and is directly anchored in the UHPC node core area (4), and the common steel bar (10) extends out of the end surface of the prefabricated concrete open-hole beam (7) and is directly anchored in the UHPC node core area (4);

the unbonded prestressed tendons (9) comprise linear, broken line or curved prestressed tendons;

the post-tensioned unbonded precast prestressed concrete open-pore superposed beam (3) is constructed and checked according to a force transmission mode matched with the common concrete open-pore simply supported beam and the support setting before a beam superposed layer (8), a plate superposed layer (19) and a UHPC node core area (4) are poured, after the node core area (4), the beam superposed layer (8) and the plate superposed layer (19) are poured, the concrete strength of the node and the superposed layer reaches the design requirement, the unbonded prestressed reinforcement (9) is tensioned, after tensioning is completed, the support is detached, and construction stage checking is carried out according to a frame beam; the post-tensioned unbonded prefabricated prestressed concrete open-hole superposed beam has different sections of upper chords at the hole openings before the beam superposed layer, the plate superposed layer and the UHPC node core area are poured and different stress states, and the construction checking calculation is carried out on the upper chords and the lower chords at the hole openings of the prefabricated concrete open-hole beam; after the prestress is established, the unbonded prestressed tendon (9) is calculated by effective prestress during construction checking calculation and checking calculation of a normal use limit state, and the stress increment is considered during checking calculation of a bearing capacity limit state;

the post-tensioned unbonded precast prestressed concrete open-pore superposed beam (3) consists of a precast concrete open-pore beam (7), a beam superposed layer (8) and a post-tensioned unbonded prestressed tendon (9); the composite slab (17) consists of a precast concrete slab (18) and a slab composite layer (19) poured on the slab;

the post-tensioned unbonded prestressed tendon (9) is pre-embedded in the precast concrete open-pore beam (7) component, penetrates through the UHPC node core area (4), and has two ends extending out of the UHPC node core area (4), wherein two ends are respectively fixedly provided with a clamp (15) and an anchorage device (16), one end is arranged on the outer side of the column, and the other end is arranged in the beam laminated layer;

the bottom surface of the precast concrete upper column (1), the top surface of the precast concrete lower column (2) and the end surface of the post-tensioned unbonded precast prestressed concrete open-pore superposed beam (3) are provided with inward-sunk grooves;

the precast concrete upper column (1) is characterized in that the precast concrete upper column (1) is fixed at a corresponding position by a reliable support (12);

the stirrups (13) in the precast concrete upper column (1), the precast concrete lower column (2) and the post-tensioned unbonded precast prestressed concrete open-hole superposed beam (3) are divided into an encrypted area and a non-encrypted area, the stirrups (14) in the UHPC node core area (4) are arranged according to design requirements, the shear-resistant bearing capacity of the core area is calculated according to an oblique compression bar and a truss model, steel fibers in the UHPC are considered to be equivalent to horizontal stirrups and vertical longitudinal bars, the contribution of the horizontal stirrups and the vertical longitudinal bars to the shear resistance of the node core area is considered, and the contribution of the unbonded prestressed bars to the shear resistance of the node is considered;

and the top surfaces of the precast concrete open pore beam (7) and the precast concrete plate (18) are provided with rough surface layers.

The earthquake-resistant design of the system comprises the following steps:

step 1: the beam and the column are designed according to the existing standard and invention patent;

step 2: checking and calculating the strength of the upper chord and the lower chord at the opening of the precast concrete open-pore beam before pouring the beam superposed layer, the plate superposed layer and the UHPC node core area of the precast prestressed concrete open-pore superposed beam;

and step 3: the open hole position in the precast prestressed concrete open-hole composite beam is located in a midspan 1/3 section as far as possible, and when the open hole position is located in a beam end 1/3 section, the distance from the edge of the open hole close to the node to the inner edge of the node is larger than 1.5 times of the height of the beam.

A post-tensioned unbonded prefabricated prestressed concrete open-pore beam frame structure system connected by UHPC is characterized by comprising the following steps:

step 1: manufacturing a precast concrete lower column (2), a precast concrete upper column (1), a precast concrete open-hole beam (7) and a precast concrete plate (18); wherein enough anchoring length is reserved for the prefabricated concrete lower column (2) and the prefabricated concrete upper column (1) to extend out of the longitudinal bar anchoring node core area (4); anchoring common steel bars (10) extending out of the precast concrete open-pore beam (7) into a node core area (4) by reserving enough anchoring length; when the precast concrete beam (7) is manufactured, the prestressed tendons (9) are pre-embedded at the design position, and enough length is reserved at the two ends;

step 2: after the maintenance of the prefabricated part is finished, hoisting the prefabricated concrete lower column (2) and installing the prefabricated concrete lower column on the foundation, and installing a sufficient number of stirrups (14) on the longitudinal main reinforcement (6) extending out of the lower column (2);

and 3, step 3: hoisting the precast concrete open pore beam (7) to the top surface of the precast concrete lower column (2), enabling the bottom surface of the precast concrete open pore beam (7) to be flush with the top surface of the precast concrete lower column (2), enabling the end part of the precast concrete open pore beam (7) to be placed on the precast concrete lower column (2), and fixing the precast concrete open pore beam by using a support; wherein, the common steel bars (10) extending out of the precast concrete open-hole beams (7) at the two sides are reasonably avoided and directly anchored in the node core area according to the construction requirement;

and 4, step 4: hoisting the precast concrete upper column (1) to be right above the precast concrete lower column (2), fixing the precast concrete upper column (1) at a corresponding position by using a reliable support (12), and binding the stirrup (14) installed in the step 2 and the column longitudinal bar together; wherein, the longitudinal bars extending out of the upper and lower precast concrete columns are reasonably avoided in the core area of the node and are directly anchored;

and 5: enabling a top through-length steel bar (11) to penetrate through a stirrup (13) reserved on a beam overlapping layer region and a node core region (4) and be bound well, then binding a pre-buried and extended pre-stressed tendon (9) in a precast concrete open-hole beam in the node core region according to a designed position, then pouring a UHPC node core region (4), and setting a template to prevent UHPC from entering a beam overlapping layer (8) part;

and 6: after the UHPC node core area (4) is maintained to have enough strength, hoisting the precast concrete flat plate (or the laminated slab, the double T plate and the secondary beam) (18) to the precast concrete open-hole beam (7) and fixing;

and 7: pouring a beam laminated layer (8) and a plate laminated layer (19);

and 8: after the concrete of the beam laminated layer (8) and the plate laminated layer (19) is cured to reach enough strength, tensioning the unbonded prestressed tendon (9);

and step 9: and repeating the manufacturing process to finish the post-tensioning unbonded prefabricated prestressed concrete open-pore beam frame structure system.

The foregoing description is only exemplary of the invention, and it is obvious that the present invention is not limited to the above-described mode, i.e., the description is not restrictive, and the invention can be easily modified, changed or substituted without departing from the method concept and technical solution of the present invention, and the modifications and changes are all within the protection scope of the present invention.

Claims (9)

1. A post-tensioned unbonded prefabricated prestressed concrete open-pore beam frame structure system connected by UHPC (ultra high performance concrete) comprises a prefabricated (or cast-in-place) concrete upper column (1), a prefabricated (or cast-in-place) concrete lower column (2), a post-tensioned unbonded prefabricated prestressed concrete open-pore superposed beam (3), an UHPC (ultra high performance concrete) node core area (4) and a superposed slab (17);

the prefabricated concrete open-pore composite beam is characterized in that an upper longitudinal main rib (5) is arranged in the prefabricated concrete upper column (1), a lower longitudinal main rib (6) is arranged in the prefabricated concrete lower column (2), a prefabricated concrete open-pore beam (7), a beam laminated layer (8) and a post-tensioned unbonded prestressed rib (9) are arranged in the post-tensioned unbonded prefabricated prestressed concrete open-pore composite beam (3), a common reinforcing steel bar (10) is arranged at the bottom of the prefabricated concrete open-pore beam (7), a hanging rib (20) and a reinforcing steel net piece (21) can be arranged around an orifice if necessary, the reinforcing steel net piece can also be a welded reinforcing steel net, a top through long reinforcing steel bar (11) is arranged in the beam laminated layer (8), and the laminated slab (17) consists of a prefabricated concrete slab (18) and a slab laminated layer (19) poured on a slab;

the novel steel structure is characterized in that the upper longitudinal main rib (5) extends out of the bottom surface of the prefabricated upper column (1) and is directly anchored in the UHPC node core area (4), the lower longitudinal main rib (6) extends out of the top surface of the prefabricated lower column (2) and is directly anchored in the UHPC node core area (4), and the common steel bar (10) extends out of the end surface of the prefabricated concrete open-hole beam (7) and is directly anchored in the UHPC node core area (4);

the unbonded prestressed reinforcing steel is characterized in that the unbonded prestressed reinforcing steel (9) comprises a linear prestressed reinforcing steel, a broken line prestressed reinforcing steel or a curved prestressed reinforcing steel;

the method is characterized in that the post-tensioned unbonded precast prestressed concrete open-pore composite beam (3) is subjected to construction checking calculation according to a force transfer mode which is adaptive to common concrete open-pore simply supported beams and support setting before a beam composite layer (8), a plate composite layer (19) and a UHPC node core area (4) are poured, after the node core area (4), the beam composite layer (8) and the plate composite layer (19) are poured, the strength of the node and composite layer concrete reaches design requirements, tensioning of unbonded prestressed ribs (9) is carried out, after tensioning is finished, supports are removed, and construction stage checking calculation is carried out according to a frame beam; the post-tensioned unbonded prefabricated prestressed concrete open-hole superposed beam has different sections of upper chords at the hole openings before the beam superposed layer, the plate superposed layer and the UHPC node core area are poured and different stress states, and the construction checking calculation is carried out on the upper chords and the lower chords at the hole openings of the prefabricated concrete open-hole beam; after the prestress is established, the unbonded prestressed tendons (9) are calculated by effective prestress during construction checking calculation and checking calculation of a normal use limit state, and the stress increment is considered during checking calculation of a bearing capacity limit state.

2. The UHPC connected post-tensioned unbonded precast prestressed concrete open-cell beam frame structure system according to claim 1, characterized in that the post-tensioned unbonded precast prestressed concrete open-cell composite beam (3) is composed of a precast concrete open-cell beam (7), a beam lamination layer (8) and a post-tensioned unbonded prestressed tendon (9); the composite slab (17) consists of a precast concrete slab (18) and a slab composite layer (19) cast on the slab.

3. The UHPC-connected post-tensioned unbonded precast prestressed concrete open-cell beam frame structure system as claimed in claim 1, wherein the post-tensioned unbonded prestressed tendons (9) are pre-embedded in the precast concrete open-cell beam (7) member, pass through the UHPC node core area (4) and extend out of the UHPC node core area (4) from both ends, the two ends of the post-tensioned unbonded prestressed tendons are respectively and fixedly provided with a clamp (15) and an anchorage device (16), one end of the post-tensioned unbonded prestressed concrete open-cell beam frame structure system is arranged outside a column, and the other end of the post-tensioned unbonded prestressed concrete open-cell beam frame structure system is arranged in a beam overlapping layer.

4. A UHPC connected post-tensioned unbonded pre-stressed concrete open-pored beam frame structure system according to claim 1, characterized in that the bottom surface of the pre-stressed concrete upper column (1), the top surface of the pre-stressed concrete lower column (2) and the end surface of the post-tensioned unbonded pre-stressed concrete open-pored composite beam (3) are provided with sunken grooves.

5. A UHPC connected post-tensioned unbonded precast prestressed concrete open-pored beam frame structure system in accordance with claim 1, characterized in that the precast concrete upper column (1) is fixed in position with a positive support (12).

6. The UHPC-connected post-tensioned unbonded precast prestressed concrete open-pore beam frame structure system as claimed in claim 1, wherein stirrups (13) in the precast concrete upper column (1), the precast concrete lower column (2) and the post-tensioned unbonded precast prestressed concrete open-pore superposed beam (3) are divided into a dense area and a non-dense area, stirrups (14) in the UHPC node core area (4) are arranged according to design requirements, the shear resistance calculation of the core area is calculated according to a diagonal compression bar and a truss model, steel fibers in the UHPC are equivalent to horizontal stirrups and vertical longitudinal bars, the contribution of the steel fibers to the shear resistance of the node core area is considered, and the beneficial contribution of the unbonded prestressed reinforcement to the shear resistance of the node core area is considered.

7. A UHPC joined post-tensioned unbonded precast prestressed concrete open-pored beam frame structure system according to claim 1, characterized in that the precast concrete open-pored beam (7) and the top surface of the precast concrete slab (18) are provided with a matte layer.

8. A method for designing a framework structure system of UHPC-connected post-tensioned unbonded precast prestressed concrete open-cell beams according to claim 1, wherein the method comprises the following steps: except that the beam and the column are designed according to the existing specification and the invention patent, the position of the open hole in the beam is positioned at the 1/3 section of the midspan as far as possible, and when the open hole is positioned at the 1/3 section of the beam end, the distance from the edge of the open hole close to the node to the inner edge of the node is larger than 1.5 times of the height of the beam.

9. A post-tensioned unbonded prefabricated prestressed concrete open-pore beam frame structure system connected by UHPC is characterized by comprising the following steps:

step 1: manufacturing a precast concrete lower column (2), a precast concrete upper column (1), a precast concrete open-hole beam (7) and a precast concrete plate (18); wherein, enough anchoring length is reserved for anchoring the precast concrete lower column (2) and the precast concrete upper column (1) into the node core area (4) by extending out of the longitudinal ribs; anchoring common steel bars (10) extending out of the precast concrete open-pore beam (7) into a node core area (4) by reserving enough anchoring length; pre-burying a prestressed tendon (9) at a design position when the precast concrete open-hole beam (7) is manufactured, and reserving enough length at two ends;

step 2: after the maintenance of the prefabricated parts is finished, hoisting the prefabricated concrete lower column (2) and installing the prefabricated concrete lower column on the foundation, and installing a sufficient number of stirrups (14) on the longitudinal main reinforcement (6) extending out of the lower column (2);

and step 3: hoisting the precast concrete open pore beam (7) to the top surface of the precast concrete lower column (2), enabling the bottom surface of the precast concrete open pore beam (7) to be flush with the top surface of the precast concrete lower column (2), enabling the end part of the precast concrete open pore beam (7) to be placed on the precast concrete lower column (2), and fixing the precast concrete open pore beam by using a support; wherein, the common steel bars (10) extending out of the precast concrete beams (7) at two sides are reasonably avoided and directly anchored in the node core area according to the construction requirements;

and 4, step 4: hoisting the precast concrete upper column (1) to be right above the precast concrete lower column (2), fixing the precast concrete upper column (1) at a corresponding position by using a reliable support (12), and binding the stirrup (14) installed in the step 2 and the column longitudinal bar together; wherein, the longitudinal bars extending out of the upper and lower precast concrete columns are reasonably avoided in the core area of the node and are directly anchored;

and 5: enabling a top full-length steel bar (11) to penetrate through a stirrup (13) reserved on a beam overlapping layer region and a node core region (4) and be bound well, then binding a pre-buried and extended prestressed tendon (9) in a precast concrete open-pore beam (7) in the node core region according to a designed position, then pouring a UHPC node core region (4), and setting a template to prevent UHPC from entering a beam overlapping layer (8) part;

and 6: after the UHPC node core area (4) is maintained to have enough strength, hoisting the precast concrete flat plate (or the laminated slab, the double T plate and the secondary beam) (18) to the precast concrete open-hole beam (7) and fixing;

and 7: pouring a beam laminated layer (8) and a plate laminated layer (19);

and 8: after the concrete of the beam laminated layer (8) and the plate laminated layer (19) is cured to reach enough strength, tensioning the unbonded prestressed tendon (9);

and step 9: and repeating the manufacturing process to finish the post-tensioning unbonded prefabricated prestressed concrete open-pore beam frame structure system.

Images