Hanging formwork structure of pit-in-pit in foundation pit and construction method thereof

Abstract

The application discloses a hoisting formwork structure of pit-in-pit in a foundation pit and a construction method thereof, and belongs to the technical field of formwork construction of foundation pit engineering. The hoisting formwork structure comprises a bottomed and uncapped formwork cylinder arranged in a pit-in-pit in the foundation pit, the formwork cylinder has opposite first and second side faces, third and fourth side faces are formed between opposite sides of the first and second side faces, and the first, second, third and fourth side faces are respectively provided with perforations. An inner support frame is supported on the inner side face of the formwork cylinder. A plurality of supporting bars are arranged along the circumferential direction of the pit opening of the pit-in-pit, one end of each supporting bar is fixedly connected to a steel bar structure of a bottom plate of the foundation pit, and the other end of each supporting bar is detachably arranged in the perforation. A tie structure is arranged in the upper port of the formwork cylinder, the tie structure comprises a plurality of cross-arranged connecting bars, and the two ends of each connecting bar are detachably connected to the other ends of the supporting bars on the opposite sides of the formwork cylinder through connecting sleeves. The hoisting formwork structure of the pit-in-pit in the foundation pit has the advantages that the construction of the hoisting formwork of the water collecting well and the elevator shaft is facilitated, the floating control measures of the hoisting formwork are simple, and the construction cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, specifically to a suspended formwork structure for a pit within a pit and its construction method. Background Technology

[0002] With the rapid development of construction technology, urban construction is increasingly extending into underground spaces. The construction of super high-rise building structures inevitably requires a tall foundation slab for support. However, due to the considerable depth of the foundation slab, the difficulty of reinforcing the formwork of the sump and elevator shafts is self-evident. During the concrete pouring process of the foundation slab, the formwork of the elevator shaft and sump often floats upwards, resulting in an excessively high pit height for these structures.

[0003] To control the floating of the suspended formwork in elevator shafts and sump pits, current technical measures generally involve fixing the formwork after installation and inspection confirming its correctness. Water-stop bolts are welded securely to the outer reinforcing steel bars of the pit wall on all four sides of the formwork to prevent it from floating during concrete pouring. A counterweight block is used on the top surface of the formwork to further prevent floating. The counterweight block is placed in a suspended basket or similar container to ensure a flat and stable base, and is then secured to prevent overturning. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, a suspended formwork structure for a pit within a pit and its construction method are provided to solve the problem of cumbersome construction of the floating control measures for suspended formwork in water collection wells and elevator shafts.

[0005] To achieve the above objectives, a suspended formwork structure for a pit within a pit is provided, comprising:

[0006] A bottomless mold cylinder is placed in a pit within a pit in an excavation pit. The mold cylinder has a first side and a second side opposite to each other. A third side and a fourth side are formed between the opposite sides of the first side and the second side. The first side, the second side, the third side and the fourth side are respectively provided with perforations.

[0007] An inner support frame is provided to support the inner side of the mold cylinder;

[0008] Multiple supporting bars are arranged along the circumferential direction of the pit opening of the pit-in-pit. One end of the supporting bar is fixedly connected to the steel reinforcement structure of the bottom plate of the pit, and the other end of the supporting bar is detachably inserted into the through hole.

[0009] A tie structure is provided in the upper port of the mold cylinder. The tie structure includes multiple cross-arranged connecting ribs. The two ends of the connecting ribs are detachably connected to the other ends of the supporting ribs on opposite sides of the mold cylinder through connecting sleeves.

[0010] Furthermore, each side of the mold cylinder is provided with at least two supporting ribs.

[0011] Furthermore, the steel reinforcement structure includes multiple horizontal and vertical bars. The horizontal bars are arranged along the length of the pit-in-pit, and the vertical bars are arranged along the width of the pit-in-pit. The horizontal bars are tied together with the vertical bars, and one end of the supporting bar is fixedly connected to multiple horizontal bars or multiple vertical bars at the opening of the pit-in-pit.

[0012] Furthermore, the multiple supporting ribs on each side of the mold cylinder are arranged at equal intervals.

[0013] Furthermore, the mold cylinder includes:

[0014] The bottom mold is positioned above the bottom of the pit within the pit;

[0015] A side mold is erected on the bottom mold, and a ring of side molds is provided along the outer edge of the bottom mold.

[0016] Furthermore, the inner support frame:

[0017] The horizontal support includes a support tube and a support member. The support tube is disposed between the side molds on opposite sides of the mold cylinder. The support member is adjustablely installed at both ends of the support tube and presses against the inner side of the side mold.

[0018] The uprights are erected on the bottom mold and connected to the support pipe.

[0019] Furthermore, the end of the support tube is formed with an internal thread, one end of the support member is formed with an external thread, one end of the support member is threaded to the end of the support tube, and the other end of the support member is pressed against the inner side of the side mold.

[0020] This invention provides a construction method for a suspended formwork structure of a pit within a pit, comprising the following steps:

[0021] Multiple support bars are arranged along the circumferential direction of the pit opening in the pit-within-a-pit within the foundation pit, and one end of the support bar is fixedly connected to the steel reinforcement structure of the bottom plate of the foundation pit, so that the other end of the support bar extends into the pit-within-a-pit.

[0022] The mold cylinder is placed in a pit within a pit in the foundation pit, and the other end of the supporting rib is detachably inserted into the perforation of the mold cylinder;

[0023] An inner support frame is installed inside the mold cylinder, and the inner support frame is supported on the inner side of the mold cylinder;

[0024] A tie structure is provided inside the upper port of the mold cylinder, such that the two ends of the connecting rib of the tie structure are detachably connected to the other ends of the supporting ribs on opposite sides of the mold cylinder through connecting sleeves.

[0025] The beneficial effects of the present invention are that the suspended formwork structure of the pit within the pit of the present invention adopts a steel structure of supporting bars connected to the bottom plate of the pit, and then uses a tie structure to tie it together, so as to prevent the formwork of the pit within the pit from floating further. On the one hand, it can effectively prevent the suspended formwork of the pit within the pit from floating up, and at the same time reduce the risk of the counterweight of the suspended basket and the sinking of the formwork in the traditional way. Moreover, the tie structure of the tie connection can be recycled. Attached Figure Description

[0026] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0027] Figure 1 This is a schematic diagram of the suspended formwork structure of the pit within a pit in an embodiment of the present invention.

[0028] Figure 2 This is a schematic diagram of the structure of the mold cylinder according to an embodiment of the present invention.

[0029] Figures 3 to 4 This is a schematic diagram illustrating the construction steps of a suspended formwork structure for a pit within a pit, according to an embodiment of the present invention. Detailed Implementation

[0030] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0032] Reference Figures 1 to 4 As shown, the present invention provides a suspended formwork structure for a pit within a pit, comprising: a formwork cylinder 1, an inner support frame 2, supporting ribs 3, and a tie structure 4.

[0033] The mold cylinder 1 is a cylindrical structure with a bottom but no cover. The mold cylinder 1 is set in the pit A within the foundation pit. The mold cylinder and the pit A within the pit form a pouring space for pouring the bottom slab structure of the pit A within the pit.

[0034] In this embodiment, the pit within the pit is a directional pit. The mold cylinder 1 has opposing first and second side surfaces. A third and fourth side surface are formed between the opposing sides of the first and second side surfaces. The first and second side surfaces are opposing sides of the mold cylinder in the width direction. The third and fourth side surfaces are opposing sides of the mold cylinder in the length direction. The first, second, third, and fourth side surfaces are each provided with a perforation.

[0035] The inner support 2 is supported on the inner side of the mold cylinder 1.

[0036] See Figure 2 As shown, the mold cylinder 1 includes a bottom mold 11 and a side mold 12.

[0037] The bottom mold 11 is positioned above the bottom of pit A within the pit. The side mold 12 is erected vertically above the bottom mold 11. The side mold 12 is arranged in a ring along the outer edge of the bottom mold 11.

[0038] Continue reading Figure 2 As shown, the inner support frame 2 provides horizontal support and the uprights 22. There are multiple horizontal supports. Some of the horizontal supports are arranged along the length of the mold cylinder, while others are arranged along the width of the mold cylinder.

[0039] Specifically, each horizontal support includes a support tube 211 and a support member 212. The support tube 211 is disposed between the side molds 12 on opposite sides of the mold cylinder 1. The support member 212 is adjustablely installed at both ends of the support tube 211. The support member 212 presses against the inner side of the side mold 12. The upright 22 is erected on the bottom mold 11. The upright 22 is connected to the support tube 211.

[0040] In this embodiment, the upright is connected to the intersection of the support tubes of two horizontally arranged cross supports.

[0041] In a preferred embodiment, the end of the support tube 211 is formed with an internal thread. One end of the support member 212 is formed with an external thread. One end of the support member 212 is threadedly connected to the end of the support tube 211. The other end of the support member 212 presses against the inner side of the side mold 12.

[0042] Continue reading Figure 1 Multiple support bars 3 are installed along the circumferential direction of the pit opening of pit A within the pit. One end of the support bar 3 is fixedly connected to the steel reinforcement structure 5 of the bottom slab of the pit. The other end of the support bar 3 is detachably inserted into the perforation.

[0043] In this embodiment, the reinforcing steel structure 5 includes multiple horizontal bars 51 and longitudinal bars 52. The horizontal bars 51 are arranged along the length direction of the pit A within the pit. The longitudinal bars 52 are arranged along the width direction of the pit A within the pit. The horizontal bars 51 and the longitudinal bars 52 are tied together. One end of the supporting bar 3 is fixedly connected to multiple horizontal bars 51 or multiple longitudinal bars 52 at the opening of the pit A within the pit.

[0044] At least two support ribs 3 are provided on each side of the mold cylinder 1. The support ribs 3 on each side of the mold cylinder 1 are evenly spaced. Specifically, the support ribs are located at equal intervals on each side of the mold cylinder, such as... Figure 1 As shown, the supporting ribs are set at three equal divisions on each side of the mold cylinder, that is, a supporting rib is set at 1 / 3 and 2 / 3 of the side mold of the mold cylinder respectively.

[0045] The tie structure 4 is disposed inside the upper port of the mold cylinder 1. Specifically, the tie structure 4 includes multiple cross-arranged connecting ribs 41. The two ends of the connecting ribs 41 are detachably connected to the other ends of the supporting ribs 3 on opposite sides of the mold cylinder 1 through connecting sleeves.

[0046] This invention provides a construction method for a suspended formwork structure of a pit within a pit, comprising the following steps:

[0047] S1: Multiple support bars 3 are set along the circumferential direction of the pit opening of the pit A in the foundation pit, and one end of the support bar 3 is fixedly connected to the steel reinforcement structure 5 of the bottom plate of the foundation pit, so that the other end of the support bar 3 extends into the pit A.

[0048] In this embodiment, the pit within a pit refers to an elevator shaft pit, a sump pit, or similar foundation pit. The supporting reinforcement bars on each side of the pit opening are perpendicular to the side of the pit within the pit. At the tri-section of the pit's edge, a supporting reinforcement bar is required to extend 10 cm beyond the side template (i.e., the side mold of the mold cylinder). This supporting reinforcement bar must be spot-welded at least three times within the binding area. At the tri-section of the pit, one side of the supporting reinforcement bar has a standard straight thread, and the other side has straight threaded bars in both directions.

[0049] S2: The mold cylinder 1 is placed in the pit A within the foundation pit, and the other end of the supporting rib 3 is detachably inserted into the perforation of the mold cylinder 1.

[0050] Assemble the cylindrical mold and make through holes in the side mold of the cylindrical mold for inserting the supporting ribs.

[0051] S3: Install an inner support frame 2 inside the mold cylinder 1. The inner support frame 2 supports the inner side of the mold cylinder 1.

[0052] S4: The tie structure 4 is set inside the upper port of the mold cylinder 1, so that the two ends of the connecting rib 41 of the tie structure 4 are detachably connected to the other ends of the support ribs 3 on opposite sides of the mold cylinder 1 through the connecting sleeve.

[0053] After the mold is reinforced, the steel bars with reserved threads on the supporting bars on opposite sides of the pit are connected by connecting sleeves (such as ordinary straight thread sleeves or positive and negative thread sleeves).

[0054] During the concrete pouring process at the bottom of the pit within the pit, the formwork is pressed down under the bottom slab of the pit within the pit by the downward pressure and limiting effect of the supporting bars and tie structures, preventing the formwork of the pit within the pit from floating. After the pouring is completed, the tie structures are dismantled and the supporting bars that extend into the formwork are cut off.

[0055] The suspended formwork structure of the pit within the pit of the present invention adopts a steel reinforcement structure that connects the bottom plate of the pit with the supporting bars, and then uses a tie structure to connect them to prevent the formwork of the pit within the pit from floating further. On the one hand, it can effectively prevent the suspended formwork of the pit within the pit from floating further, and at the same time reduce the risk of the counterweight of the suspended basket and the sinking of the formwork in traditional measures. Moreover, the tie structure of the tie connection can be reused.

[0056] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A suspended formwork structure for a pit within a pit in an excavation pit, characterized in that, include: A bottomless mold cylinder is placed in a pit within a pit in an excavation pit. The mold cylinder has a first side and a second side opposite to each other. A third side and a fourth side are formed between the opposite sides of the first side and the second side. The first side, the second side, the third side and the fourth side are respectively provided with perforations. An inner support frame is provided to support the inner side of the mold cylinder; Multiple supporting bars are arranged along the circumferential direction of the pit opening of the pit-in-pit. One end of the supporting bar is fixedly connected to the steel reinforcement structure of the bottom plate of the pit, and the other end of the supporting bar is detachably inserted into the through hole. A tie structure is provided in the upper port of the mold cylinder. The tie structure includes multiple cross-arranged connecting ribs. The two ends of the connecting ribs are detachably connected to the other ends of the supporting ribs on opposite sides of the mold cylinder through connecting sleeves.

2. The suspended formwork structure for a pit within a pit as described in claim 1, characterized in that, At least two supporting ribs are provided on each side of the mold cylinder.

3. The suspended formwork structure for a pit within a pit as described in claim 2, characterized in that, The steel reinforcement structure includes multiple horizontal and vertical bars. The horizontal bars are arranged along the length of the pit-in-pit, and the vertical bars are arranged along the width of the pit-in-pit. The horizontal bars are tied together with the vertical bars. One end of the supporting bar is fixedly connected to multiple horizontal bars or multiple vertical bars at the opening of the pit-in-pit.

4. The suspended formwork structure for a pit within a pit as described in claim 2, characterized in that, The multiple supporting ribs on each side of the mold cylinder are arranged at equal intervals.

5. The suspended formwork structure for a pit within a pit as described in claim 1, characterized in that, The mold cylinder includes: The bottom mold is positioned above the bottom of the pit within the pit; A side mold is erected on the bottom mold, and a ring of side molds is provided along the outer edge of the bottom mold.

6. The suspended formwork structure for a pit within a pit as described in claim 5, characterized in that, The internal support frame includes: The horizontal support includes a support tube and a support member. The support tube is disposed between the side molds on opposite sides of the mold cylinder. The support member is adjustablely installed at both ends of the support tube and presses against the inner side of the side mold. The uprights are erected on the bottom mold and connected to the support pipe.

7. The suspended formwork structure for a pit within a pit as described in claim 6, characterized in that, The end of the support tube has an internal thread, and one end of the support member has an external thread. One end of the support member is threaded to the end of the support tube, and the other end of the support member is pressed against the inside of the side mold.

8. A construction method for a suspended formwork structure for a pit within a pit as described in any one of claims 1 to 7, characterized in that, Includes the following steps: Multiple support bars are arranged along the circumferential direction of the pit opening in the pit-within-a-pit within the foundation pit, and one end of the support bar is fixedly connected to the steel reinforcement structure of the bottom plate of the foundation pit, so that the other end of the support bar extends into the pit-within-a-pit. The mold cylinder is placed in the pit within the pit, and the other end of the supporting rib is detachably inserted into the through hole of the mold cylinder; An inner support frame is installed inside the mold cylinder, and the inner support frame is supported on the inner side of the mold cylinder; A tie structure is provided inside the upper port of the mold cylinder, such that the two ends of the connecting rib of the tie structure are detachably connected to the other ends of the supporting ribs on opposite sides of the mold cylinder through connecting sleeves.

Images