CN111733863B

CN111733863B - Tower crane foundation for foundation pit and construction method thereof

Info

Publication number: CN111733863B
Application number: CN202010591244.7A
Authority: CN
Inventors: 黄恺
Original assignee: Jiangsu Ningqiang Construction Co ltd
Current assignee: Jiangsu Ningqiang Construction Co ltd
Priority date: 2020-06-24
Filing date: 2020-06-24
Publication date: 2021-08-31
Anticipated expiration: 2040-06-24
Also published as: CN111733863A

Abstract

The invention relates to a tower crane foundation for a foundation pit and a construction method thereof, belonging to the field of tower crane foundations. The tower crane foundation structure has the advantages that the lifting frame is arranged, the possibility of rusting caused by long-time contact of the tower crane foundation section and the embedded column leg with moisture is reduced, meanwhile, the tower crane foundation section is lifted above the bottom surface of the foundation pit, workers do not need to enter a tower crane well when maintaining the tower crane foundation section, and the middle noon can be piled up around the tower crane without arranging a retaining wall, so that the space utilization rate in the foundation pit is improved.

Description

Tower crane foundation for foundation pit and construction method thereof

Technical Field

The invention relates to the technical field of tower crane foundations, in particular to a tower crane foundation for a foundation pit and a construction method thereof.

Background

The foundation pit is a space below the ground excavated for constructing a foundation and a basement of a building (including a structure). Tower cranes are also called tower cranes. The tower crane has large operation space and is mainly used for vertical and horizontal conveying of materials and installation of building components in building construction. The tower crane foundation is the foundation of a tower crane, and practice proves that a great number of major safety accidents are caused by the problems of the tower crane foundation, and the tower crane foundation is an important factor influencing the integral stability of the tower crane.

In the existing setting process of the tower crane operating in the foundation pit, a retaining wall needs to be built before the tower crane foundation pit is backfilled, a tower crane well and a water suction pump are arranged to continuously pump water, and the conditions that the strength of the tower crane foundation is reduced, the bearing capacity is reduced and the potential safety hazard is caused due to the fact that underground humid environment causes corrosion of components such as tower crane foundation sections and bolts are prevented.

The above prior art solutions have the following drawbacks: in the use of later stage tower crane, when the tower crane maintained, the workman need get into in the tower crane well, could maintain the tower crane foundation section to receive retaining wall intensity restriction, the tower crane periphery can't carry on the heavy object heap and carry, and peripheral place can't utilize, makes job site space utilization reduce.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide the tower crane foundation for the foundation pit and the construction method thereof, which have the effects of avoiding workers from entering a tower crane well for maintenance, stacking the peripheral space of the tower crane and improving the space utilization rate.

One of the above objects of the present invention is achieved by the following technical solutions:

the utility model provides a tower crane foundation for foundation ditch, is including pouring the cushion cap, it buries underground in the below ground to pour the cushion cap part, pour on the top surface of pouring the cushion cap and be provided with lifting frame, lifting frame's top level sets up, lifting frame is interior pre-buried to have a plurality of pre-buried column legs, each pre-buried column leg perpendicular to lifting frame's top respectively and stretching out from the top.

Through adopting above-mentioned technical scheme, it buries underground in the ground to pour the cushion cap part, play to each structure of pouring on the cushion cap and make and stable function, through setting up lifting support, the pre-buried column leg that will be used for installing the tower crane base node promotes to above the foundation ditch bottom surface, because the base node is installed and is lifted the support top, reduce rivers and the base node of tower crane and component direct contact such as bolt, cause the condition that corrodes and influence structural strength, because it lifts the base node to the ground of foundation ditch through lifting the frame on, the staff of being convenient for maintains the base node of tower crane, simultaneously owing to need not to set up retaining wall, make the staff carry out the heavy object heap in tower crane peripheral space and carry, the space utilization of job site has been promoted.

The present invention in a preferred example may be further configured to: and stable rib plates are fixedly arranged on the circumferential side walls of the embedded column legs embedded into the lifting frame.

Through adopting above-mentioned technical scheme, the embedded column leg buries the part that lifts the frame and sets up firm floor, and firm floor has increased embedded column leg and the contact nep that lifts the frame to promote bonding strength and stability, reduced it and received the load and taken place the possibility of slope and skew, promoted foundation ditch structure's reliable degree.

The present invention in a preferred example may be further configured to: and a mortar masonry pan corner is arranged at one end, extending out of the embedded column leg, of the top end of the lifting frame.

Through adopting above-mentioned technical scheme, through using the mortar coating to stretch out the position of lifting the frame on lifting the frame in the pre-buried spud leg, reduced moisture content and stretched into the concrete from the space in, reduced the concrete and the pre-buried spud leg the tiny space in long-term catchment, cause the possibility of pre-buried spud leg corruption.

The present invention in a preferred example may be further configured to: the lifting frame comprises a plurality of frame columns and a plurality of frame beams, the frame columns are arranged in a cast-in-place mode, the frame beams are arranged in a partially prefabricated mode, the embedded column legs and the prefabricated parts of the frame beams are integrally cast and fixed, and the prefabricated parts of the frame beams form complete frame beams in a cast-in-place mode and are connected with the frame columns into a whole.

Through adopting above-mentioned technical scheme, because the frame post field pouring sets up, make the frame post stronger with the tuberculosis nature of pouring the cushion cap to easily adjust the actual height of frame post according to the actual conditions on site, and be convenient for make level between each frame post top surface, through the frame roof beam of practical prefabricated formula, shortened the time limit for a project, and compare in the mode of field pouring, reduced the position error of each pre-buried post leg through prefabricated mode support frame roof beam.

The present invention in a preferred example may be further configured to: the frame beam is characterized in that a first pouring groove is formed in the frame column, a cast-in-place groove is formed in the upper side of the prefabricated part of the frame beam, a second pouring groove is formed in the cast-in-place groove, the first pouring groove is communicated with the second pouring groove, and the first pouring groove and the second pouring groove are inclined downwards and extend.

By adopting the technical scheme, because the first pouring groove and the second pouring groove which are communicated with each other and extend obliquely downwards are arranged, when the frame beam and the frame column are poured and connected to form the integral lifting frame in site pouring, concrete slurry is slowly injected from the lower notch of the first pouring groove, is filled into the first pouring groove, the second pouring groove and the inner side of the pouring mold from bottom to top, the generation of bubbles is reduced, the pouring dead angle is reduced, the pouring quality is improved, meanwhile, the bonding strength between the frame beam and the frame column is improved through the cast-in-place pouring part after the concrete is solidified in the first pouring groove and the second pouring groove, and the condition that the frame beam and the frame column are separated due to load bearing is reduced.

The present invention in a preferred example may be further configured to: the frame post is located the notch department of first filling tank and is equipped with the seal assembly, the seal assembly includes the installation piece of fixed connection on the frame post, set up the mouth of filling with first filling tank intercommunication on the installation piece, the circumference that lies in the mouth of filling on the installation piece has set firmly the flange ring, fixedly connected with rotates the seat on the circumference lateral wall of flange ring, rotate the apron that is connected with and flange ring looks adaptation on the seat.

Through adopting above-mentioned technical scheme, the flange ring on the installation piece is convenient for the staff and is connected the concrete pump with the installation piece, and the concrete thick liquid pours into first filling tank into from the inboard mouth that pours of flange ring in, the staff through will dry the board rotatory to with the flange ring laminating after pouring to seal the mouth that pours, promoted the concrete and poured and mouthful confined convenience, shortened the time limit for a project.

The present invention in a preferred example may be further configured to: the first perfusion groove and the second perfusion groove are arranged in parallel, inner supporting pieces are arranged in the first perfusion groove and the second perfusion groove and comprise center rods arranged in parallel with the first perfusion groove and the second perfusion groove, a plurality of inner supporting plates parallel to the center rods are circumferentially arranged on the center rods, the inner supporting plates are connected with the center rods through connecting pieces, and the connecting pieces are made of memory metal materials.

Through adopting above-mentioned technical scheme, before pouring into the concrete in first filling tank and the second filling tank, the staff at first compresses tightly each interior extension board of interior branch spare to well core rod direction, it is the connection board that memory metal made takes place buckling deformation, thereby make the distance between interior extension board and the well core rod reduce, put back in first filling tank and the second filling tank with interior extension spare, the deformation of connection board resumes gradually, each interior extension board supports on the inside wall of first filling tank and second filling tank, after the concrete grout that pours solidifies, the steel reinforcement cage in first filling tank and the second filling tank is equivalent to interior inner support spare, the concrete strength of frame roof beam with the frame post junction has been promoted, further promote joint strength.

The present invention in a preferred example may be further configured to: the pouring bearing platform comprises a base plate and a base platform, the base platform is fixedly arranged above the base plate, and the frame column and the base platform are integrally poured and connected.

Through adopting above-mentioned technical scheme, through setting up the base plate, increased the conflict area of basis and soil layer in the horizontal direction to reduced and pour the cushion cap and taken place the possibility of empting, the base station has increased the conflict area of basis and soil layer in vertical side, has reduced and has pour the cushion cap and take place the possibility that squints in the horizontal direction, thereby has promoted the stability of pouring the cushion cap.

The present invention in a preferred example may be further configured to: a plurality of L-shaped reinforcing rods are arranged in the pouring bearing platform, the bottom edges of the L-shaped reinforcing rods are parallel to the base plate and are embedded in the base plate, the vertical ends of the L-shaped reinforcing rods are embedded in the base platform and extend out of the top end of the base platform, and the parts of the L-shaped reinforcing rods extending out of the top end of the base platform are poured into the frame columns and are embedded in the frame columns.

Through adopting above-mentioned technical scheme, through the setting of L shape stiffener, strengthened joint strength and structural strength between base plate, base station and the frame post, reduced the frame post and taken place to empty and the possibility of buckling.

The invention also aims to provide a construction method of the tower crane foundation for the foundation pit, which comprises the following steps:

a1, digging a bearing platform foundation pit, and flattening and tamping the bottom of the bearing platform foundation pit until the compaction coefficient of the bottom of the bearing platform foundation pit is more than or equal to 0.97;

a2, arranging a base plate mold and a reinforcement cage at the bottom of the foundation pit of the bearing platform, welding and fixing the L-shaped reinforcing rods and the reinforcement cage, and pouring concrete at the bottom of the foundation pit of the bearing platform to form a base plate;

a3, after the concrete of the base plate is initially set, disassembling a mould of the base plate, welding a reinforcement cage used by the base platform, installing a base platform mould, and pouring the base platform;

and A4, after the concrete of the base platform is finally solidified, disassembling the base platform mould, and backfilling the foundation pit of the bearing platform.

A5, after backfilling of a foundation pit of a bearing platform, welding a steel reinforcement cage on a base platform, installing a frame column mold, pouring a frame column, and installing a sealing assembly on the frame column mold before pouring so that the sealing assembly and the frame column are integrally poured and connected;

a6, after the concrete of the frame columns is finally set, disassembling a frame column mould, placing the prefabricated part of the frame beam on each frame column, communicating the first pouring groove and the second pouring groove, and leveling each frame beam;

a7, installing a frame beam mold after leveling, extruding and deforming the built-in piece, placing the built-in piece into a first pouring groove and a second pouring groove, after the built-in piece recovers deformation and abuts against the inner walls of the first pouring groove and the second pouring groove, injecting concrete grout from a pouring port of a sealing assembly, pouring concrete into the first pouring groove, filling the first pouring groove, the second pouring groove and a cast-in-place groove from bottom to top until the frame beam mold is filled, and troweling the upper surface of the concrete after the concrete grout fills the mold;

and A8, finishing the construction of the bearing platform foundation pit tower crane foundation after the concrete slurry of the frame beam is finally set.

By adopting the technical scheme, the construction and the construction of the tower crane foundation of the foundation pit are realized, and the strength of the tower crane foundation and the stability of the whole structure are improved.

In summary, the invention includes at least one of the following beneficial technical effects:

1. the lifting frame is arranged, so that the possibility of rusting caused by long-time contact of the tower crane base section and the embedded column leg with moisture is reduced, meanwhile, the tower crane base section is lifted above the bottom surface of the foundation pit, workers do not need to enter a tower crane well when maintaining the tower crane base section, and a heavy object can be piled around the tower crane without arranging a retaining wall, so that the space utilization rate in the foundation pit is improved;

2. through setting up interior branch spare, the inner branch spare stretches into first filling tank and second filling tank to cast-in-place partial pouring of frame roof beam is accomplished, the concrete thick liquid solidifies the back, and the inner branch spare forms the steel reinforcement cage in first filling tank and second filling tank, promotes the structural strength of junction.

Drawings

FIG. 1 is a schematic diagram for embodying a structural entirety in an embodiment of a tower crane foundation for a foundation pit disclosed in the present application.

Fig. 2 is an enlarged schematic view of a portion a in fig. 1.

FIG. 3 is a schematic cross-sectional view for embodying an L-shaped reinforcing rod in an embodiment of a tower crane foundation for a foundation pit disclosed in the present application.

FIG. 4 is a schematic cross-sectional structure diagram for embodying the positions of a first filling groove and a second filling groove in an embodiment of a tower crane foundation for a foundation pit disclosed in the present application.

FIG. 5 is a schematic diagram of a pre-buried column leg structure used in an embodiment of a tower crane foundation for a foundation pit disclosed in the present application.

FIG. 6 is a schematic diagram of an embodiment of a tower crane foundation for a foundation pit for embodying an internal support structure as disclosed herein.

In the figure, 1, a bearing platform is poured; 11. a substrate; 12. a base station; 13. an L-shaped stiffener; 2. a lifting frame; 21. a frame column; 211. a first perfusion channel; 22. a frame beam; 221. a cast-in-place trough; 222. a second perfusion channel; 3. pre-burying the column legs; 31. stabilizing the rib plate; 4. a closure assembly; 41. mounting blocks; 411. an infusion port; 42. a flange ring; 43. a rotating seat; 431. a cover plate; 5. an inner branch; 51. a center pole; 52. connecting sheets; 53. an inner support plate.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

According to fig. 1, for this application embodiment discloses a tower crane foundation for foundation ditch, including pouring cushion cap 1, pour cushion cap 1 and include base plate 11 and base platform 12 two parts, base plate 11 buries underground and the level setting, and base platform 12 sets firmly in base plate 11 top. And reinforcing cages for reinforcing structures are arranged in the base plate 11 and the base 12. Base plate 11 has increased the area of contact of pouring cushion cap 1 and soil layer in the horizontal direction, and base station 12 has increased the area of contact of pouring cushion cap 1 and soil layer on vertical direction to pour the stability of cushion cap 1 has been promoted

As shown in fig. 1 and 3, a lifting frame 2 is cast on the base platform 12, and the lifting frame 2 includes a frame column 21 and a frame beam 22 on top of the frame column 21. A plurality of L-shaped reinforcing rods 13 are embedded in the base plate 11 and the base platform 12 together, the bottom ends of the L-shaped reinforcing rods 13 are arranged in parallel to the ground and embedded in the base plate 11, the L-shaped reinforcing rods 13 are embedded in the base platform 12 and vertically extend, and the top ends of the L-shaped reinforcing rods extend out of the base platform 12 and go deep into the frame column 21. Four frame columns 21 are provided, and frame beams 22 are respectively placed on the top ends of two adjacent frame columns 21. Through setting up lifting frame 2 and installing the base section of tower crane on lifting frame 2 top, reduced the base section of tower crane and the condition that high strength bolt etc. and water long-term contact and be corroded. Meanwhile, the base section is positioned above the ground surface, so that the maintenance of the base section of the tower crane by workers is facilitated. In addition, because the retaining wall is not required to be arranged, the staff can pile heavy objects around the tower crane, and the space utilization rate in the foundation pit is improved.

Referring to fig. 4 and 5, the frame columns 21 of the lifting frame 2 are cast in situ, the frame beams 22 are made by partially prefabricating, a plurality of embedded column legs 3 are embedded in the frame beams 22, the top ends of the embedded column legs 3 extend out of the frame beams 22, cement mortar is coated on the extending positions of the top ends of the embedded supports of the frame beams 22 to form mortar masonry corners (not shown in the figure), and the corrosion of the embedded column legs 3 caused by water permeating into the concrete structure from gaps and accumulating in the concrete structure is reduced. Through the mode that frame beam 22 predetermines, compare in the mode of cast in situ, because the interference of having discharged site operation, the location of prefabricated formula frame beam 22 to pre-buried column leg 3 is more accurate. The upper side of the prefabricated part of the frame beam 22 is provided with a cast-in-place groove 221, the bottom of the cast-in-place groove 221 is provided with a second pouring groove 222, the corresponding position on the frame column 21 is provided with a first pouring groove 211, the first pouring groove 211 is communicated with the corresponding second pouring groove 222, and one end, far away from the second pouring groove 222, of the first pouring groove 211 is communicated with the side wall of the frame column 21. When the frame beam 22 is poured, a worker pours concrete slurry from the first pouring groove 211 to the cast-in-place groove 221 and the inner side of the mold through the concrete slurry pump, and the concrete slurry is gradually filled into the first pouring groove 211 and the second pouring groove 222 from bottom to top, so that the possibility of filling dead corners is reduced, the possibility of generating air bubbles is reduced, the pouring quality is improved, and the bonding strength of the frame beam 22 and the frame column 21 is improved through the concrete slurry solidified in the first pouring groove 211 and the second pouring groove 222.

As shown in fig. 4 and 6, the inner supporting member 5 is disposed in the first filling channel 211 and the second filling channel 222 together, the inner supporting member 5 includes a central rod 51, a connecting piece 52 is disposed on a circumferential side wall of the central rod 51, the connecting piece 52 is made of a memory metal material and is provided with a bending portion, one end of the connecting piece 52 away from the central rod 51 is fixedly connected with an inner supporting plate 53, and the inner supporting plate 53 is abutted against inner walls of the first filling channel 211 and the second filling channel 222 respectively. Before pouring, a worker presses each inner support plate 53 of the inner support 5 towards the central rod 51, puts the inner support 5 into the first pouring groove 211 and the second pouring groove 222, and after each connecting sheet 52 of the inner support 5 is restored, each inner support plate 53 is enabled to abut against the inner groove walls of the first pouring groove 211 and the second pouring groove 222, so that the frame beam 22 and the frame column 21 are pre-positioned before pouring. After concrete grout is poured, the inner supporting piece 5 is equivalent to a steel reinforcement cage, and the joint between the frame beam 22 and the frame column 21 is reinforced.

As shown in fig. 2, an installation block 41 is fixedly arranged on the side wall of the frame column 21 at the notch of the first pouring slot 211, a pouring opening 411 communicated with the first pouring slot 211 is arranged on the installation block 41, and a flange ring 42 for connecting with a concrete pump nozzle is fixedly arranged on the installation block 41. Fixedly connected with rotates seat 43 on the flange circumference lateral wall, rotates to rotate and is connected with apron 431 on the seat 43, and the staff rotates apron 431 and makes apron 431 keep off flange ring 42 front side and then through spraying glass cement etc. sealed with apron 431's circumference after having accomplished pouring to the concrete, reduces the possibility that the concrete thick liquid seepage influences the quality of pouring. The convenience of concrete grout pouring and slot closure is promoted by the flange ring 42 and the cover plate 431.

The implementation principle of the embodiment is as follows: through setting up the support that lifts, make the pre-buried column leg 3 of installation tower crane foundation joint promote to above the foundation ditch bottom surface to make the foundation joint promote to subaerial, reduce the water current and tower crane's foundation joint and components direct contact such as bolt, cause the condition that corrodes and influence structural strength. Meanwhile, the base section is lifted to the ground of the foundation pit, so that the base section of the tower crane can be maintained by workers conveniently, and on the other hand, a retaining wall is not required to be arranged, so that heavy object piling and loading can be carried out in the peripheral space of the tower crane in the construction process, and the space utilization rate of a construction site is improved.

The embodiment of the application also discloses a construction method of the tower crane foundation for the foundation pit, which comprises the following steps

A1, excavating a foundation pit of a bearing platform, leveling and tamping the bottom of the foundation pit of the bearing platform until the compaction coefficient of the bottom of the foundation pit of the bearing platform is more than or equal to 0.97, wherein when the foundation pit of the bearing platform is excavated, firstly excavating the foundation pit to a depth of more than 300mm by an excavating machine, then excavating the residual earthwork manually, considering effective measures of side slope enclosure and drainage reduction, avoiding overbreak in the excavation process, if a disturbance part is excavated by disturbance, selecting graded sandstone for layer tamping and backfilling, and tamping again until the compaction coefficient is more than or equal to 0.97;

a2, arranging a base plate 11 mould and a reinforcement cage at the bottom of the foundation pit of the bearing platform, fixedly welding the L-shaped reinforcing rods 13 with the reinforcement cage, pouring concrete at the bottom of the foundation pit of the bearing platform to form the base plate 11, wherein the thickness of the base plate 11 is at least 100 mm;

a3, after the concrete of the base plate 11 is initially set, detaching a mould of the base plate 11, welding a reinforcement cage used by the base 12, installing a mould of the base 12, pouring the base 12, wherein the thickness of the base plate 11 is at least 300mm, and the base plate 11 and the base 12 are both poured by C15 plain concrete;

and A4, after the concrete of the base platform 12 is finally solidified, disassembling the mould of the base platform 12, and curing the whole pouring bearing platform 1 after pouring is finished. Backfilling the foundation pit of the bearing platform after the maintenance is finished;

a5, after backfilling of a foundation pit of a bearing platform, welding a steel reinforcement cage on the base platform 12, installing a frame column 21 mould, pouring the frame column 21, installing a sealing component 4 on the frame column 21 mould before pouring, and integrally pouring and connecting the sealing component 4 and the frame column 21; .

A6, after concrete of the frame columns 21 is finally set, disassembling the frame column 21 mold, placing prefabricated parts of the frame beams 22 on each frame column 21, communicating the first pouring groove 211 with the second pouring groove 222, leveling each frame beam 22, setting the frame columns 21 and the frame beams 22 to complete the requirement that the lifting frame 2 is at least 100-200mm higher than the natural elevation of the ground, and finding slopes outwards to avoid rainwater accumulation and corrosion of the tower body;

a7, mounting a frame beam 22 mould after leveling, extruding and deforming the inner support 5, placing the inner support 5 into the first pouring groove 211 and the second pouring groove 222, pouring concrete slurry from the pouring port 411 of the sealing component 4 after the inner support 5 recovers deformation and abuts against the inner walls of the first pouring groove 211 and the second pouring groove 222, pouring the concrete into the first pouring groove 211, filling the first pouring groove 211, the second pouring groove 222 and the cast-in-place groove 221 from bottom to top until the frame beam 22 mould is filled, and troweling the upper surface of the concrete after the mould is filled with the concrete slurry;

and A8, finishing the construction of the bearing platform foundation pit tower crane foundation after the concrete slurry of the frame beam 22 is finally set, and finally smearing M10 cement mortar on the position of the embedded column leg 3 extending out of the frame beam 22 to form a mortar masonry pan angle and reduce the water permeation into the concrete structure to corrode the embedded column leg 3.

The embodiments of the present invention are preferred embodiments of the present invention, and the scope of the present invention is not limited by these embodiments, so: all equivalent changes made according to the structure, shape and principle of the invention are covered by the protection scope of the invention.

Claims

1. The utility model provides a tower crane basis for foundation ditch which characterized in that: the device comprises a pouring bearing platform (1), wherein part of the pouring bearing platform (1) is embedded under the ground, a lifting frame (2) is poured on the top surface of the pouring bearing platform (1), the top end of the lifting frame (2) is horizontally arranged, a plurality of embedded column legs (3) are embedded in the lifting frame (2), and each embedded column leg (3) is perpendicular to the top end of the lifting frame (2) and extends out of the top end;

the lifting frame (2) comprises a plurality of frame columns (21) and a plurality of frame beams (22), the frame columns (21) are arranged in a cast-in-place mode, the frame beams (22) are arranged in a partially prefabricated mode, the embedded column legs (3) and the prefabricated parts of the frame beams (22) are integrally cast and fixed, and the prefabricated parts of the frame beams (22) form complete frame beams (22) in a cast-in-place mode and are connected with the frame columns (21) into a whole;

a first pouring groove (211) is formed in the frame column (21), a cast-in-place groove (221) is formed in the upper side of the prefabricated part of the frame beam (22), a second pouring groove (222) is formed in the cast-in-place groove (221), the first pouring groove (211) is communicated with the second pouring groove (222), and the first pouring groove (211) and the second pouring groove (222) are both arranged in a downward inclined and extending mode;

a sealing component (4) is arranged at a notch of the frame column (21) in the first pouring groove (211), the sealing component (4) comprises a mounting block (41) fixedly connected to the frame column (21), a pouring opening (411) communicated with the first pouring groove (211) is formed in the mounting block (41), a flange ring (42) is fixedly arranged on the mounting block (41) in the circumferential direction of the pouring opening (411), a rotating seat (43) is fixedly connected to the circumferential side wall of the flange ring (42), and a cover plate (431) matched with the flange ring (42) is rotatably connected to the rotating seat (43);

the first pouring groove (211) and the second pouring groove (222) are arranged in parallel, an inner supporting piece (5) is arranged in the first pouring groove (211) and the second pouring groove (222), the inner supporting piece (5) comprises a central rod (51) which is arranged in parallel with the first pouring groove (211) and the second pouring groove (222), a plurality of inner supporting plates (53) which are parallel to the central rod (51) are circumferentially arranged on the central rod (51), the inner supporting plates (53) are connected with the central rod (51) through connecting plates (52), and the connecting plates (52) are made of memory metal materials.

2. The tower crane foundation for the foundation pit according to claim 1, wherein: and stable rib plates (31) are fixedly arranged on the circumferential side walls of the embedded column legs (3) embedded into the lifting frame (2).

3. The tower crane foundation for the foundation pit as claimed in claim 2, wherein: and a mortar masonry angle is arranged at one end, extending out of the embedded column legs (3), of the top end of the lifting frame (2).

4. The tower crane foundation for the foundation pit according to claim 3, wherein: the pouring bearing platform (1) is divided into a base plate (11) and a base platform (12), the base platform (12) is fixedly arranged above the base plate (11), and the frame column (21) and the base platform (12) are integrally poured and connected.

5. The tower crane foundation for the foundation pit according to claim 4, wherein: be equipped with a plurality of L shape stiffener (13) in pouring cushion cap (1), L shape stiffener (13) base parallel to base plate (11) and bury underground in base plate (11), L shape stiffener (13) vertical end is buried underground in base station (12) and is stretched out from base station (12) top, L shape stiffener (13) are poured into frame post (21) from the part that base station (12) top stretched out and are buried underground in the inside of frame post (21).

6. A construction method of a tower crane foundation for a foundation pit, comprising the tower crane foundation for the foundation pit of claim 5, characterized by comprising the steps of:

a2, arranging a base plate (11) mould and a reinforcement cage at the bottom of the foundation pit of the bearing platform, welding and fixing the L-shaped reinforcing rods (13) with the reinforcement cage, and pouring concrete at the bottom of the foundation pit of the bearing platform to form the base plate (11);

a3, after the concrete of the base plate (11) is initially set, disassembling a mould of the base plate (11), welding a reinforcement cage used by the base platform (12), installing the mould of the base platform (12), and pouring the base platform (12);

a4, after the concrete of the base platform (12) is finally set, disassembling the mould of the base platform (12), and backfilling the foundation pit of the bearing platform;

a5, after backfilling of a foundation pit of a bearing platform is finished, welding a reinforcement cage on a base platform (12), installing a frame column (21) mould, pouring the frame column (21), installing a sealing component (4) on the frame column (21) mould before pouring, and integrally pouring and connecting the sealing component (4) and the frame column (21);

a6, after the concrete of the frame columns (21) is finally set, disassembling the frame column (21) mould, placing the prefabricated part of the frame beam (22) on each frame column (21), communicating the first pouring groove (211) with the second pouring groove (222), and leveling each frame beam (22) by using the mould;

a7, after leveling, installing a frame beam (22) mould, extruding and deforming an inner support piece (5), placing the inner support piece (5) into a first pouring groove (211) and a second pouring groove (222), after the inner support piece (5) recovers deformation and abuts against the inner walls of the first pouring groove (211) and the second pouring groove (222), pouring concrete slurry from a pouring port (411) of a sealing component (4), pouring the concrete into the first pouring groove (211), filling the first pouring groove (211), the second pouring groove (222) and a cast-in-place groove (221) from bottom to top until the frame beam (22) mould is filled, and after the mould is filled with the concrete slurry, leveling the upper surface of the concrete;

and A8, finishing the construction of the bearing platform foundation pit tower crane foundation after the concrete slurry of the frame beam (22) is finally set.