CN214460442U - Pre-tensioning precast concrete supporting member and inner supporting system - Google Patents

Abstract

The utility model discloses a pre-tensioning precast concrete supporting component and an inner supporting system, which belongs to the field of underground foundation pit engineering, in particular to a pre-tensioning precast concrete supporting component, comprising a concrete structure and two end steel structures; the concrete structure comprises concrete with a hollow part, a steel reinforcement framework and a plurality of prestressed longitudinal reinforcements are arranged in the concrete, two ends of the steel reinforcement framework are respectively connected with two end steel structures, and two ends of each prestressed longitudinal reinforcement respectively penetrate through prestressed reinforcement tensioning holes of the two end steel structures upwards and are anchored in the end steel structures; the utility model also provides an interior braced system, the assembled interior support that its adopted is formed by the concatenation of foretell pretensioning method precast concrete supporting component, and wherein is equipped with between two adjacent pretensioning method precast concrete supporting components at least and dismantles the cushion. The utility model discloses can improve bearing capacity, anti deformability, wholeness and the node rigidity that the assembled supported, can also reduce the degree of difficulty that precast concrete supporting member dismantled, improve the dismantlement efficiency that the assembled supported.

Description

Pre-tensioning precast concrete supporting member and inner supporting system

Technical Field

The utility model belongs to the technical field of underground foundation ditch engineering, concretely relates to pretensioning method precast concrete supporting element and interior braced system.

Background

Traditional cast in situ concrete supports, because of its rigidity is big, the wholeness is good, advantages such as safe and reliable, generally apply to underground works, nevertheless also have outstanding problem and shortcoming: (1) cost, high investment: concrete support belongs to temporary engineering, a main body of a station structure is finished, namely outward transportation is broken, the investment of temporary waste engineering is high, generally, underground stations are millions, complex stations are tens of millions, and the cost of complex stations is tens of millions; (2) time-consuming and long construction period: supporting a formwork by concrete, binding reinforcing steel bars, pouring and vibrating, maintaining and removing at the later stage, wherein the whole process is long for several months, and the site construction progress is seriously restricted; (3) hard, the degree of difficulty is big: the concrete support construction difficulty is high, and a large amount of manpower and material resources are consumed to break the construction after the use; (4) the concrete is not environment-friendly, the waste residues of the concrete are broken to pollute the environment, and the development direction of green construction, environmental protection and energy conservation is not met. Advanced products and scientific construction methods are urgently needed to replace the traditional concrete support.

Although the traditional steel pipe support can be recycled and is convenient to construct, the traditional steel pipe support and a foundation pit retaining structure can only bear pressure, and the traditional steel pipe support has poor integrity and poor deformation resistance and becomes a weak link for foundation pit safety; moreover, when the existing fabricated concrete support is disassembled, the support usually bears large pressure and is long, so that the disassembling of the fabricated support with the length of several meters still has great difficulty after bolts among prefabricated support sections are unscrewed under huge pressure stress.

Disclosure of Invention

In order to overcome the not enough of above-mentioned prior art existence, the utility model aims at providing a pretension method precast concrete supporting element and interior braced system can improve bearing capacity, anti deformability, wholeness and the middle node rigidity that the assembled supported, can also reduce the degree of difficulty that precast concrete supporting element dismantled, improves the dismantlement efficiency that the assembled supported.

In order to achieve the purpose, the technical scheme of the utility model is that the pre-tensioning precast concrete supporting component comprises a concrete structure and two end steel structures arranged at two ends of the supporting direction of the concrete structure; the concrete structure comprises concrete with a hollow part penetrating along a supporting direction, a steel bar framework and a plurality of prestressed longitudinal bars are arranged in the concrete, and two ends of the steel bar framework are respectively connected with two end steel structures; and a plurality of prestressed tendon tensioning holes corresponding to the plurality of prestressed longitudinal tendons are formed in the two end head steel structures, and two ends of each prestressed longitudinal tendon respectively penetrate through the prestressed tendon tensioning holes corresponding to the two end head steel structures upwards and are anchored in the end head steel structures.

Furthermore, the end steel structure comprises an outer flange and an inner flange which are oppositely arranged, and an inner ring pipe and a plurality of stiffening ribs are arranged between the outer flange and the inner flange; two ends of the inner ring pipe are respectively connected with the outer flange and the inner flange, and three side surfaces of each stiffening rib are respectively connected with the outer flange, the inner ring pipe and the inner flange; the steel bar framework is connected with the inner flange; the inner flange is provided with the prestressed tendon tensioning hole, and the end part of the prestressed longitudinal tendon passes through the prestressed tendon tensioning hole and is anchored on the inner flange.

Furthermore, an outer ring pipe is connected to one side of the inner flange, which is far away from the outer flange, and the end part of the concrete structure is positioned in the outer ring pipe.

Furthermore, a circle of meshing teeth are arranged on the inner wall of one end, far away from the inner flange, of the outer ring pipe and embedded into the concrete.

Furthermore, the steel bar framework comprises a spiral stirrup and a plurality of non-prestressed longitudinal bars, and the non-prestressed longitudinal bars are arranged at intervals along the outer side of the spiral stirrup and are connected with the spiral stirrup; and the plurality of longitudinal prestressed ribs are arranged at intervals along the inner side of the spiral stirrup.

The utility model also provides an internal support system, which comprises an enclosure structure, a crown beam, a waist beam and an assembled internal support; the top of the enclosure structure is provided with a crown beam, the inner side of the enclosure structure is provided with a waist beam, and the assembled inner supports are supported between two opposite sides of the waist beam and between two opposite sides of the crown beam; the fabricated inner support is formed by splicing the pre-tensioning precast concrete supporting members, and a disassembling cushion block is arranged between at least two adjacent pre-tensioning precast concrete supporting members; embedded parts are embedded in the crown beam or the waist beam, and the end steel structures at two ends of the assembled inner support are respectively connected with the embedded parts at two sides.

Furthermore, a plurality of bolt holes are formed in the circumferential direction of the outer flange of the end steel structure of the pre-tensioning precast concrete supporting member, and the corresponding bolt holes in the adjacent outer flanges of the adjacent pre-tensioning precast concrete supporting members are respectively connected through bolts.

Furthermore, the embedded part comprises an embedded outer steel plate, an embedded inner steel ring and a plurality of spiral sleeves; two ends of each spiral sleeve are respectively connected with the embedded outer steel plate and the embedded inner steel ring; a plurality of bolt holes are formed in the embedded outer steel plate and the embedded inner steel ring and correspond to the plurality of screw sleeves and the plurality of bolt holes in the outer flange one by one; the embedded part and the end steel structure respectively sequentially penetrate through a corresponding bolt hole in the outer flange, a corresponding bolt hole in the embedded outer steel plate, an inner hole in the corresponding spiral sleeve and a corresponding bolt hole in the embedded inner steel ring through a plurality of screws to be connected.

Compared with the prior art, the utility model discloses following beneficial effect has:

(1) the utility model discloses an assembled supports and adopts the concatenation of pretensioning precast concrete supporting component to form, the both ends of pretensioning precast concrete supporting component adopt the end steel construction to increase the bearing capacity of joint department, adopt hollow concrete structure in the middle of, dispose steel reinforcement framework and many prestressing force vertical bars in the interior and improve intensity, and steel reinforcement framework and prestressing force vertical bars all are connected with the end steel construction, impel end steel construction and concrete structure to melt an organic whole, make the bearing capacity (intensity) of assembled support high, anti deformability (rigidity) is big, can reach the requirement of the degree of safety that even surpasss conventional concrete support; meanwhile, the steel support is light in weight, high in strength, convenient to recycle, convenient to transport and mount and higher in economical efficiency than a pure assembly type steel support; the construction method is simple, and a special anchorage device is not needed;

(2) the utility model discloses a set up the dismantlement gasket between at least certain two adjacent prefabricated supporting members in the assembled support to can demolish the dismantlement gasket earlier when dismantling, eliminate the axial force between the prefabricated supporting member, reduce the degree of difficulty that the assembled support was dismantled, improve the dismantlement efficiency of assembled support;

(3) the prefabricated support members and the crown beam or the waist beam are rigidly connected, so that the integrity and the safety of the foundation pit are ensured; and the prefabricated supporting members and the embedded parts are connected by bolts or screws, so that the prefabricated supporting members are convenient to mount and dismount, and the prefabricated supporting members can be recycled.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a plan view of an internal support system provided by an embodiment of the present invention;

fig. 2 is a longitudinal sectional view of a pre-tensioning precast concrete supporting member according to an embodiment of the present invention;

fig. 3 is a cross-sectional view of a pre-tensioned precast concrete supporting member at an intermediate position according to an embodiment of the present invention;

fig. 4 is a cross-sectional view of a pre-tensioned precast concrete supporting member end position according to an embodiment of the present invention;

fig. 5 is a longitudinal sectional view (without a disassembly pad block) of a connection node structure of a pre-tensioning precast concrete support member according to an embodiment of the present invention;

fig. 6 is a longitudinal sectional view (with a detachable spacer) of a connection node structure of a pre-tensioning precast concrete supporting member according to an embodiment of the present invention;

fig. 7 is a cross-sectional view of a connection node structure of a pre-tensioning precast concrete supporting member according to an embodiment of the present invention;

fig. 8 is a schematic view illustrating a connection between a pretensioned precast concrete support member and a crown beam according to an embodiment of the present invention;

fig. 9 is a schematic view of an embedded part provided in an embodiment of the present invention;

fig. 10 is a schematic view of an inner flange provided in an embodiment of the present invention;

fig. 11 is a schematic view of an outer flange according to an embodiment of the present invention;

FIG. 12 is a schematic view of a stiffener according to an embodiment of the present invention;

fig. 13 is a schematic view of a pre-buried inner steel ring provided in an embodiment of the present invention;

fig. 14 is a schematic view of a pre-buried outer steel plate according to an embodiment of the present invention;

fig. 15 is a cross-sectional view of a support according to an embodiment of the present invention;

fig. 16 is a top view of a support according to an embodiment of the present invention;

in the figure: 1. an enclosure structure; 2. a crown beam; 3. prefabricating a concrete supporting member by a pre-tensioning method; 4. embedding parts; 5. an end steel structure; 6. a support; 7. an inner ring pipe; 8. an outer flange; 9. a stiffening rib; 10. an inner flange; 11. an outer ring pipe; 12. non-prestressed longitudinal bars; 13. pre-stressed longitudinal bars; 14. a spiral stirrup; 15. concrete; 16. a bolt; 17. disassembling the cushion block; 18. bolt holes; 19. pre-burying an outer steel plate; 20. a spiral sleeve; 21. pre-burying an inner steel ring; 22. a screw; 23. tensioning holes of the prestressed tendons; 24. concave steel blocks; 25. steel legs; 26. a concrete base; 27. and (4) meshing the teeth.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

Example one

As shown in fig. 2 to 4, the embodiment provides a pre-tensioning precast concrete supporting member 3, which includes a concrete structure and two end steel structures 5 disposed at two ends of the concrete structure in a supporting direction; the concrete structure comprises concrete 15 with a hollow part penetrating along a supporting direction, a steel reinforcement framework and a plurality of prestressed longitudinal ribs 13 are arranged in the concrete 15, and two ends of the steel reinforcement framework are respectively connected with two end steel structures 5; the two end steel structures 5 are respectively provided with a plurality of prestressed tendon tensioning holes 23 corresponding to the plurality of prestressed longitudinal tendons 13, and two ends of each prestressed longitudinal tendon 13 respectively penetrate through the prestressed tendon tensioning holes 23 corresponding to the two end steel structures 5 upwards and are anchored in the end steel structures 5. The middle of the precast concrete supporting member of the embodiment adopts a hollow concrete structure, and the two ends of the precast concrete supporting member adopt end steel structures 5, so that the advantages of two materials, namely steel and concrete, can be fully exerted; the end steel structure 5 is additionally arranged at the end head, so that the rigid connection between the two prefabricated supporting components is facilitated, and the bearing capacity of the joint is improved; the middle of the hollow concrete structure is a pure hollow reinforced concrete structure, the bearing capacity is sufficient, the manufacturing cost can be effectively reduced, a steel reinforcement framework and a plurality of prestressed longitudinal ribs 13 are arranged in the middle hollow concrete structure, the prestressed longitudinal ribs 13 can enable the hollow concrete supporting member to be subjected to prestress action after being formed, the strength is higher, the damage in transportation and use is prevented, the steel reinforcement framework can solve the problem that the hollow concrete support is bent, the supporting strength is increased, the steel reinforcement framework and the prestressed longitudinal ribs 13 are connected with the end steel structure 5, the end steel structure 5 and the concrete 15 are enabled to be integrated, the bearing capacity (strength) of the prefabricated supporting member is high, the deformation resistance (rigidity) is large, the safety requirement of even exceeding that the conventional concrete support can be achieved, and the prefabricated supporting member is not easy to damage; meanwhile, the steel support is light in weight, high in strength, convenient to recycle, convenient to transport and mount and higher in economical efficiency than a pure assembly type steel support; and the construction method is simple and does not need a special anchorage device.

In this embodiment, the cross section of the concrete structure is a concrete tubular structure, and may be a circular ring, a square ring, a polygonal ring, or the like; the concrete 15 can be made of other materials such as ultra-high-strength concrete, and construction and steam curing are realized through a centrifugal process in a factory, so that a rapid high-strength process effect is realized; the concrete 15 is hollow, the thickness is about 100mm-200mm, a small value is preferably adopted under the condition of meeting the supporting rigidity so as to reduce the self weight of the member, any inner wall is not added in the hollow part in the concrete 15, the hollow part can also adopt a form with the inner wall, and the material of the inner wall can be steel pipes, PVC and the like; the end steel structure 5 is made of high-strength steel.

Further, the end steel structure 5 comprises an outer flange 8 and an inner flange 10 which are oppositely arranged, and an inner ring pipe 7 and a plurality of stiffening ribs 9 are arranged between the outer flange 8 and the inner flange 10; two ends of the inner ring pipe 7 are respectively connected with the outer flange 8 and the inner flange 10, and three side surfaces of each stiffening rib 9 are respectively connected with the outer flange 8, the inner ring pipe 7 and the inner flange 10; the steel reinforcement framework is connected with the inner flange 10; the inner flange 10 is provided with the prestressed tendon tensioning hole 23, and the end part of the prestressed longitudinal tendon 13 penetrates through the prestressed tendon tensioning hole 23 and is anchored on the inner flange 10. As shown in fig. 2, the inner collar 7, the outer flange 8, the inner flange 10 and the stiffening ribs 9 at the end of the pre-tensioned precast concrete supporting member 3 of this embodiment form a shoe beam joint to increase the rigidity of the joint, and three sides of the stiffening ribs 9 are welded to the inner collar 7, the outer flange 8 and the inner flange 10, respectively, to ensure the rigidity of the joint at the joint.

In the embodiment, the inner ring pipe 7 can be a steel pipe with the wall thickness of 10-30mm, the inner diameter of the steel pipe is consistent with that of a concrete hollow part in a concrete structure, two ends of the inner ring pipe 7 are respectively welded with an outer flange 8 and an inner flange 10, and a stiffening rib 9 is welded on the outer wall of the inner ring pipe 7; as shown in fig. 11, the outer flange 8 may be a steel ring with a wall thickness of 10-30mm, the inner and outer diameters of the steel ring are completely the same as the inner and outer diameters of the concrete 15 in the concrete structure, and a plurality of bolt holes 18 are uniformly arranged in the circumferential direction of the outer flange 8; as shown in fig. 10, the size of the inner flange 10 is completely consistent with that of the outer flange 8, the thickness is preferably 10-30mm, the prestressed tendon tensioning holes 23 are circumferentially and uniformly arranged, the number of the prestressed tendon tensioning holes 23 is consistent with that of the prestressed longitudinal tendons 13, one side of the inner flange 10 is welded with the inner ring pipe 7 and the stiffening ribs 9, and the other side is welded with the non-prestressed longitudinal tendons 12, the spiral stirrups 14 and the outer ring pipe 11, so as to play a role in connecting the concrete structure and the end steel structure 5; and the shapes of the inner ring pipe 7, the outer flange 8 and the inner flange 10 are matched with the shape of the cross section of the concrete structure, namely when the cross section of the concrete structure is in a ring shape, the inner ring pipe 7 is circular, the outer flange 8 and the inner flange 10 are both in a ring shape, when the cross section of the concrete structure is in a square ring shape, the inner ring pipe 7 is square, and the outer flange 8 and the inner flange 10 are both in a square ring shape.

Furthermore, the stiffening rib 9 is a rectangular steel plate with chamfered corners, and two corners of the side edge of the stiffening rib 9 connected with the inner ring pipe 7 are both chamfered. As shown in fig. 2 and 12, three sides of the stiffening rib 9 of the present embodiment are respectively welded to the inner annular tube 7, the outer flange 8 and the inner flange 10, and two corners of the side edge connecting the stiffening rib 9 and the inner annular tube 7 are chamfered to form a chamfer structure, thereby effectively reducing stress concentration during welding; wherein, the thickness of the stiffening rib 9 is preferably 20-30mm, the length is the same as the inner ring pipe 7, and the height is the difference of the inner diameter and the outer diameter of the outer flange 8 to reduce the thickness of the inner ring pipe 7; a plurality of stiffening ribs 9 may be arranged at equal intervals between the outer flange 8 and the inner flange 10, as shown in fig. 7, one stiffening rib 9 may be arranged at intervals of every 3 bolts 16, so as to improve the strength and rigidity of the connection node.

Furthermore, an outer collar 11 is connected to the inner flange 10 on the side facing away from the outer flange 8, and the end of the concrete structure is located inside the outer collar 11. The outer sleeve of the concrete structure tip of this embodiment has outer ring pipe 11, not only can protect the concrete of tip, makes the support be difficult for receiving the damage, but also has established the common atress tie of end steel construction 5 and middle concrete structure through outer ring pipe 11. Wherein, the shape of the outer ring pipe 11 is matched with the cross section shape of the concrete structure, and can be a steel pipe with the wall thickness of 8-20mm, and the material can be high-strength steel, alloy steel and other materials; the length of the outer ring 11 is about 300-500mm, and one end is welded with the inner flange 10 to bear force together.

Furthermore, a ring of engaging teeth 27 is provided on the inner wall of the outer collar 11 at the end far from the inner flange 10, and the engaging teeth 27 are embedded in the concrete 15. In the embodiment, the end of the outer ring pipe 11 far away from the inner flange 10 is provided with the meshing teeth 27 which form a common stressed whole with the concrete 15; the engaging teeth 27 are steel blocks protruding into the concrete 15 and are uniformly welded on the inner wall of the outer ring pipe 11, and the number of the engaging teeth is preferably 10-20.

Further, the steel bar framework comprises a spiral stirrup 14 and a plurality of non-prestressed longitudinal bars 12, wherein the non-prestressed longitudinal bars 12 are arranged at intervals along the outer side of the spiral stirrup 14 and are connected with the spiral stirrup 14; a plurality of longitudinal prestressed tendons 13 are arranged at intervals along the inner side of the spiral stirrup 14. As shown in fig. 2-4, a plurality of non-prestressed longitudinal bars 12 are disposed in the concrete 15 of this embodiment along the supporting direction, and the plurality of non-prestressed longitudinal bars 12 are disposed at intervals outside the spiral stirrup 14 and welded to the spiral stirrup 14, so as to improve the strength of the concrete structure; and the both ends of many non-prestressed vertical muscle 12 weld with the inside of the inner flange 10 of both ends head steel construction 5 respectively, the both ends of spiral stirrup 14 can weld with the inside of the inner flange 10 of both ends head steel construction 5 respectively, make concrete structure and end steel construction 5 closely link into an organic whole, improve the wholeness of prefabricated component, and the non-prestressed vertical muscle 12 can solve the bending problem that the assembled supported, increase the ductility that the concrete prefabrication supported, spiral stirrup 14 can play the fixed action to non-prestressed vertical muscle 12 and prestressed vertical muscle 13, spiral stirrup 14 can play the cuff effect to concrete 15 simultaneously, increase the support strength.

Example two

The embodiment provides an internal support system, which comprises an envelope structure 1, a crown beam 2, a waist beam and an assembled internal support; the top of the enclosure structure 1 is provided with a crown beam 2, the inner side of the enclosure structure 1 is provided with a waist beam, and the assembled inner supports are supported between two opposite sides of the waist beam and between two opposite sides of the crown beam 2; the fabricated inner support is formed by splicing a plurality of pre-tensioning precast concrete supporting members 3 provided by the first embodiment, and a disassembling cushion block 17 is arranged between at least two adjacent pre-tensioning precast concrete supporting members 3; embedded parts 4 are embedded in the crown beam 2 or the waist beam, and the end steel structures 5 at two ends of the assembled inner support are respectively connected with the embedded parts 4 at two sides. As shown in fig. 1 and fig. 5 to 8, at least one disassembling cushion block 17 is arranged in the fabricated inner support of this embodiment, and the disassembling cushion block 17 is placed between two of the pre-tensioning precast concrete supporting members 3, so that the disassembling cushion block 17 can be disassembled first during disassembly, the axial force between the pre-tensioning precast concrete supporting members 3 is eliminated, and the rest precast members can be disassembled easily, thereby effectively solving the problem of difficulty in disassembling the fabricated support with the length of several meters, and improving the disassembling efficiency of the fabricated support.

In this embodiment, the disassembling cushion block 17 may be a steel ring with a thickness of 30-100mm, the size of which is completely the same as that of the outer flange 8, or may be a steel ring formed by splicing multiple sections, such as two semicircular steel rings or multiple fan-shaped steel rings, and the multiple sections of steel rings are not connected; the surface of the disassembling cushion block 17 needs to be smooth, a layer of lubricant can be coated on the two side surfaces of the disassembling cushion block 17 before construction, the lubricating agent is arranged between the two prefabricated support members, the first breakthrough point is used when the assembling support is disassembled, the size of the disassembling cushion block 17 is small, the lubricating agent is coated, the disassembling difficulty is much smaller, once the disassembling cushion block 17 is disassembled, the axial force of the whole assembling support disappears, and the prefabricated support members can be easily disassembled one by one. The drawings of the present embodiment are explained taking the crown beam 2 as an example, and the case of the wale refers to the crown beam 2.

The hollow parts of the plurality of pre-tensioning precast concrete supporting members 3 of the fabricated inner support of the embodiment are communicated, so that the fabricated support has higher bearing capacity and stronger deformation resistance; the pre-tensioning precast concrete supporting member 3 can be provided with a plurality of fixed modulus sections with proper lengths according to needs, and is not suitable for overlong, hoisting construction due to overlong length, and difficult connection due to excessive joints caused by overlong length; as an implementation mode, the pre-tensioning precast concrete supporting members 3 can be designed with standard modulus of 4m, 5m, 6m and the like and end section modulus of 2m, and the pre-tensioning precast concrete supporting members 3 with completely the same, incompletely the same or completely different length specifications are selected for assembly according to the actual foundation pit requirements, so that the requirements of foundation pit supporting with different widths and lengths are met, and the universal applicability is realized.

Furthermore, a plurality of bolt holes 18 are circumferentially arranged on the outer flange 8 of the end steel structure 5 of the pre-tensioning precast concrete supporting member 3, and the corresponding bolt holes 18 on the adjacent outer flanges 8 of the adjacent pre-tensioning precast concrete supporting members 3 are respectively connected through bolts 16. As shown in fig. 5 and 6, the end of the pre-tensioning precast concrete supporting member 3 of the embodiment adopts a shoe beam joint, and is connected by a plurality of bolts 16, so that the rigid connection of the middle joint is ensured, the equal strength of the joint and the member is realized, the integrity, the rigidity and the bearing capacity of the assembled support which are the same as or similar to those of the cast-in-place concrete support are ensured, the safety of the foundation pit is ensured, the assembly and disassembly are convenient, and the factory production and the large-area popularization and application are facilitated; during splicing, a plurality of bolt holes 18 on the outer flanges 8 adjacent to the two pre-tensioning precast concrete supporting members 3 are respectively aligned, and then bolts 16 are installed in the bolt holes 18 on the same straight line for fixing, so that splicing between the pre-tensioning precast concrete supporting members 3 is realized.

Furthermore, a plurality of bolt holes are arranged on the disassembling cushion block 17 along the annular direction, and the bolt holes on the disassembling cushion block 17 correspond to the bolt holes 18 on the outer flange 8 one by one; for the pre-tensioning precast concrete supporting members 3 with the disassembling cushion blocks 17 arranged between them, bolts 16 sequentially pass through the corresponding bolt holes 18 on the outer flange 8 of one of the pre-tensioning precast concrete supporting members 3, the corresponding bolt holes on the disassembling cushion blocks 17 and the corresponding bolt holes 18 on the outer flange 8 of the other pre-tensioning precast concrete supporting member 3, so as to realize the splicing of the adjacent pre-tensioning precast concrete supporting members 3; the disassembling cushion block 17 is annular, the shape of the disassembling cushion block is the same as that of the inner flange 10 and the outer flange 8, and the inner diameter and the outer diameter of the disassembling cushion block are respectively completely the same as those of the inner flange 10 and the outer flange 8.

Further, as shown in fig. 8 and 9, the embedded part 4 includes an embedded outer steel plate 19, an embedded inner steel ring 21 and a plurality of screw sleeves 20; two ends of each spiral sleeve 20 are respectively connected with the embedded outer steel plate 19 and the embedded inner steel ring 21; a plurality of bolt holes 18 are formed in the embedded outer steel plate 19 and the embedded inner steel ring 21 and correspond to the plurality of screw sleeves 20 and the plurality of bolt holes 18 in the outer flange 8 one by one; the embedded part 4 and the end steel structure 5 respectively penetrate through the corresponding bolt hole 18 on the outer flange 8, the corresponding bolt hole 18 on the embedded outer steel plate 19, the inner hole of the corresponding spiral sleeve 20 and the corresponding bolt hole 18 on the embedded inner steel ring 21 in sequence through a plurality of screws 22 to be connected. As shown in fig. 13-14, the embedded part 4 in this embodiment is integrally embedded in the crown beam 2 or the wale, and the embedded outer steel plate 19 is tightly attached to the inner side of the crown beam 2 or the wale and used as a template of the crown beam 2 or the wale during casting; the embedded outer steel plate 19 is a round steel plate (or a square steel plate according to the requirement), the thickness is preferably 10-20mm, and the size is slightly larger than the outer diameter of the cross section of the prefabricated support; a plurality of bolt holes 18 are uniformly distributed around the pre-buried outer steel plate 19, and the number and the arrangement positions of the bolt holes 18 are the same as those of the outer flange 8; the shape and the size of the embedded inner steel ring 21 can be completely consistent with those of the outer flange 8, and the thickness is selected according to the requirement; the embedded inner steel ring 21 is deeply embedded in the crown beam 2 or the waist beam, mainly plays a role in anchoring the screw rod 22 and the spiral sleeve 20, cannot be recycled, and can be made of a material lower than that of the steel member of the end steel structure 5 to save cost; the screw sleeve 20 is a steel sleeve with threads inside, and the inside diameter of the screw sleeve is consistent with the outside diameter of the screw 22; one end of the spiral sleeve 20 is welded on the embedded outer steel plate 19, and the other end is welded on the embedded inner steel ring 21; the middle hole of the screw sleeve 20 is aligned with the bolt holes 18 of the embedded outer steel plate 19 and the embedded inner steel ring 21.

In the embodiment, all steel structures such as the inner ring pipe 7, the outer flange 8, the outer ring pipe 11, the inner flange 10, the stiffening ribs 9 and other parts which are directly contacted with the outside need to be coated with antirust materials in advance, so that the surface of the steel structures is prevented from being rusted and damaged, and the strength is prevented from being reduced; the bolts 16 are high-strength bolts.

EXAMPLE III

As shown in fig. 2 to 4, the present embodiment provides a construction method of a pre-tensioning precast concrete supporting member 3 according to an embodiment, including the steps of:

s1, producing the end steel structure 5 in a steel structure factory in batches;

s2, binding the non-prestressed longitudinal bars 12, the prestressed longitudinal bars 13 and the spiral stirrups 14 in the prefabricated part processing plant, and spot-welding the non-prestressed longitudinal bars 12 and the spiral stirrups 14 to form a reinforcement cage;

s3, conveying the end steel structure 5 to a prefabricated part processing plant, welding the non-prestressed longitudinal ribs 12 with the inner flange 10 of the end steel structure 5, and penetrating the prestressed longitudinal ribs 13 through the prestressed rib tensioning holes 23 on the inner flange 10 of the end steel structure 5;

s4, putting the structure integrated by the end steel structure 5 and the reinforcement cage into a precast tubular pile production line, tensioning the prestressed longitudinal ribs 13, and anchoring the prestressed longitudinal ribs to the inner flange 10;

s5, pouring high-strength concrete 15, forming by a centrifugal process, and curing by high-pressure steam to reach the designed strength;

and S6, removing the mould to form the pre-tensioning precast concrete supporting member 3.

In the embodiment, the concrete 15 with the hollow part can be formed by adopting a centrifugal process, and a pipe pile prefabrication production line is slightly improved, so that compared with the conventional cast-in-place vibration process, the cast-in-place vibration process is more favorable for realizing high-strength concrete, and the hollow concrete structure has higher bearing capacity and deformation resistance and better durability; other processes may also be used to accomplish this.

In the production process, the end steel structure is prefabricated by a steel structure processing factory, and the concrete pouring is completed in a prefabricated part processing factory, so that the steel structure processing and the concrete pouring are separated, the advantages of the steel structure processing factory and the prefabricated part processing factory can be fully exerted, the field welding operation in a prefabricated concrete factory is avoided, and the product quality is ensured.

Example four

As shown in fig. 1, the present embodiment provides a construction method of an internal support system provided in the second embodiment, including the following steps:

s1, prefabricating the pre-tensioning precast concrete supporting members 3, the embedded parts 4 and the disassembly cushion blocks 17 in a factory, and transporting to a construction site;

s2, splicing the pre-tensioning precast concrete supporting members 3 with different lengths section by section through bolts 16 according to the width of the foundation pit, and meanwhile installing a disassembling cushion block 17 between at least two adjacent pre-tensioning precast concrete supporting members 3 to assemble an assembled support with the length matched with the width of the foundation pit; and the end steel structures 5 at the two ends of the assembled support are connected with the embedded part 4 through a screw rod 22;

when the two pre-tensioning precast concrete supporting members 3 are spliced, the outer flanges 8 at the end parts of the two precast members are aligned, and then bolts 16 sequentially penetrate through the outer flanges 8 at the end parts of the two precast members to realize the splicing of the two precast members; when two prefabricated parts with the disassembly cushion blocks 17 arranged in the middle are assembled, firstly, a layer of lubricant is coated on two side surfaces of the disassembly cushion blocks 17, then the disassembly cushion blocks 17 are placed between the two prefabricated parts, and bolts 16 sequentially penetrate through bolt holes 18 on an outer flange 8 at the end part of one prefabricated part, bolt holes on the disassembly cushion blocks 17 and bolt holes 18 on an outer flange 8 at the end part of the other prefabricated part;

s3, embedding the support 6 at the inner support position of the foundation pit; constructing a steel connecting beam for a foundation pit provided with the middle temporary upright post;

the concrete method for embedding the support 6 comprises the following steps: the concrete base 26 is constructed firstly, the steel legs 25 are embedded in the concrete base 26, and then the concave steel blocks 24 with grooves on the upper surface are welded on the steel legs 25. As shown in fig. 15-16, the concave steel block 24 has a concave groove on its upper surface, and the concave groove matches with the shape of the concrete structure of the pre-tensioning precast concrete supporting member 3, so as to facilitate the installation of the fabricated support, and when the strength of the cast crown beam 2 or wale does not reach the designed strength, the prefabricated support is temporarily supported; the support 6 of the embodiment can also adopt other structural forms, and can play a temporary supporting role on the assembled support; under the condition that each component of the support 6 can bear the self weight of the prefabricated support, the size of each component is reduced as much as possible so as to reduce the self weight;

s4, hoisting the assembled supports, and placing the assembled supports on a support 6 to place the embedded parts 4 at two ends of each assembled support at the positions of the crown beam 2 or the waist beam to be poured; the horizontal center line of the prefabricated support is ensured, and the center of the prefabricated support is positioned in the center of the crown beam 2 or the waist beam; for the construction of the steel connecting beam, the fabricated supports are arranged on the support 6 and the steel connecting beam;

s5, pouring the crown beam 2 or the waist beam to embed the embedded part 4 in the embedded part, wherein the embedded outer steel plate 19 of the embedded part 4 is used as a template of the crown beam 2 or the waist beam to ensure that the end of the screw 22 is positioned outside the crown beam 2 or the waist beam and is not wrapped by concrete, so that later-stage disassembly is facilitated;

s6, after the crown beam 2 or the waist beam reaches the design strength, excavating foundation pit earthwork under the fabricated support, and withdrawing the support 6;

s7, after construction is finished, firstly, unscrewing the bolts 16 on the two pre-tensioning precast concrete supporting members 3 with the dismantling cushion blocks 17 arranged in the middle, dismantling the dismantling cushion blocks 17, realizing support pressure relaxation and eliminating axial force between the precast concrete supporting members;

s8, unscrewing the bolts 16 segment by segment and recovering the pretensioned precast concrete support members 3.

In the embodiment, the embedded parts 4 at the two ends of the fabricated support are firstly placed at the positions of the crown beam 2 or the waist beam to be cast, then the crown beam 2 or the waist beam is cast, and meanwhile, the embedded parts 4 at the two ends of the fabricated support are cast in the embedded parts, so that the strength of the two ends of the fabricated support and the node of the crown beam 2 or the waist beam is improved, and the safety and the stability of foundation pit engineering are ensured; and the pre-tensioning method precast concrete supporting members 3 are connected by adopting the bolts 16, and the high-strength bolts 16 are removed to realize the recovery of the precast members, so that the recycling is realized for multiple times, and the cost is reduced.

The assembled support in the embodiment can be rigidly connected with the crown beam 2 or the waist beam, so that in the ultra-deep foundation pit, the assembled support can replace a plurality of traditional concrete supports, and the assembly rate is improved.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (8)

1. A pretensioning precast concrete supporting member is characterized in that: the device comprises a concrete structure and two end steel structures arranged at two ends of the concrete structure in the supporting direction; the concrete structure comprises concrete with a hollow part penetrating along a supporting direction, a steel bar framework and a plurality of prestressed longitudinal bars are arranged in the concrete, and two ends of the steel bar framework are respectively connected with two end steel structures; and a plurality of prestressed tendon tensioning holes corresponding to the plurality of prestressed longitudinal tendons are formed in the two end head steel structures, and two ends of each prestressed longitudinal tendon respectively penetrate through the prestressed tendon tensioning holes corresponding to the two end head steel structures upwards and are anchored in the end head steel structures.

2. A pre-tensioned precast concrete supporting structure as recited in claim 1, wherein: the end steel structure comprises an outer flange and an inner flange which are oppositely arranged, and an inner ring pipe and a plurality of stiffening ribs are arranged between the outer flange and the inner flange; two ends of the inner ring pipe are respectively connected with the outer flange and the inner flange, and three side surfaces of each stiffening rib are respectively connected with the outer flange, the inner ring pipe and the inner flange; the steel bar framework is connected with the inner flange; the inner flange is provided with the prestressed tendon tensioning hole, and the end part of the prestressed longitudinal tendon passes through the prestressed tendon tensioning hole and is anchored on the inner flange.

3. A pre-tensioned precast concrete supporting structure as recited in claim 2, wherein: and one side of the inner flange, which is far away from the outer flange, is connected with an outer ring pipe, and the end part of the concrete structure is positioned in the outer ring pipe.

4. A pre-tensioned precast concrete supporting structure as recited in claim 3, wherein: and a circle of meshing teeth are arranged on the inner wall of one end, far away from the inner flange, of the outer ring pipe and embedded into the concrete.

5. A pre-tensioned precast concrete supporting structure as recited in claim 1, wherein: the steel bar framework comprises a spiral stirrup and a plurality of non-prestressed longitudinal bars, and the non-prestressed longitudinal bars are arranged at intervals along the outer side of the spiral stirrup and are connected with the spiral stirrup; and the plurality of longitudinal prestressed ribs are arranged at intervals along the inner side of the spiral stirrup.

6. An internal support system, characterized by: the prefabricated beam comprises an enclosure structure, a crown beam, a waist beam and an assembled inner support; the top of the enclosure structure is provided with a crown beam, the inner side of the enclosure structure is provided with a waist beam, and the assembled inner supports are supported between two opposite sides of the waist beam and between two opposite sides of the crown beam; the assembled inner support is formed by splicing a plurality of the pre-tensioning precast concrete supporting members according to any one of claims 1 to 5, and a detaching cushion block is arranged between at least two adjacent pre-tensioning precast concrete supporting members; embedded parts are embedded in the crown beam or the waist beam, and the end steel structures at two ends of the assembled inner support are respectively connected with the embedded parts at two sides.

7. An internal support system as defined in claim 6, wherein: the outer flange of the end steel structure of the pre-tensioning precast concrete supporting member is provided with a plurality of bolt holes along the circumferential direction, and the corresponding bolt holes on the adjacent outer flanges of the adjacent pre-tensioning precast concrete supporting members are respectively connected through bolts.

8. An internal support system as defined in claim 7, wherein: the embedded part comprises an embedded outer steel plate, an embedded inner steel ring and a plurality of spiral sleeves; two ends of each spiral sleeve are respectively connected with the embedded outer steel plate and the embedded inner steel ring; a plurality of bolt holes are formed in the embedded outer steel plate and the embedded inner steel ring and correspond to the plurality of screw sleeves and the plurality of bolt holes in the outer flange one by one; the embedded part and the end steel structure respectively sequentially penetrate through a corresponding bolt hole in the outer flange, a corresponding bolt hole in the embedded outer steel plate, an inner hole in the corresponding spiral sleeve and a corresponding bolt hole in the embedded inner steel ring through a plurality of screws to be connected.

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