A cantilever component template construction method and cantilever component construction method

Abstract

The invention relates to a cantilever component template construction method and a cantilever component construction method, comprising the following steps: constructing foundation pit retaining piles before foundation pit excavation; tying a steel cage of a crown beam on the top of the foundation pit retaining piles; using soil or rock as a bearing layer, tying a front wing steel cage of the template on one side of the crown beam steel bars, and tying a rear wing steel cage of the template on the other side of the crown beam steel bars; pouring concrete on the crown beam, the front wing of the template and the rear wing of the template to form a template of the cantilever component. By adopting the method of the invention, the template construction is simple, the workload is small, and the construction period is shortened.

Description

Technical Field

[0001] The invention relates to the field of construction engineering, and in particular to a cantilever component template construction method and a cantilever component construction method. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Nuclear power plants or civilian projects are subject to certain factors (construction period, operating space, construction logic, etc.), and some structural load-bearing components need to be cantilevered for construction. For example, in foundation pit projects, when the foundation pit is not backfilled, the construction of the bottom plate of the structure on the top of the foundation pit requires that the partial bottom plate be cantilevered to a certain distance inside the foundation pit. The traditional construction method is to excavate the foundation pit first, and after the foundation pit support is completed, the formwork is supported in the bottom plate construction area. At this time, there is no support at the bottom of the formwork. The support of the formwork needs to be supported by columns inside the foundation pit or by adding diagonal braces from the side walls of the foundation pit. After the formwork is fixed, the steel bars can be tied to the formwork, and finally the pouring of the bottom plate is completed. This traditional construction method has the following problems: First, the foundation pit of nuclear power plants or large-scale civilian projects is often deep, and they are generally "dangerous and major projects". The work of supporting the cantilever formwork is difficult, the workload on site is large, and the amount of scaffolding work is large; second, the effect of the cantilever formwork support is not easy to guarantee, which makes it difficult to ensure the quality of the bottom plate of the cantilever component; third, the formwork support time is long, which increases the construction period. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a cantilever component formwork construction method, which can easily ensure the support effect under low workload.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] In a first aspect, an embodiment of the present invention provides a cantilever member formwork construction method, comprising the following steps:

[0007] Before excavating the foundation pit, construct the foundation pit retaining piles;

[0008] Tie the steel cage of the cap beam on the top of the foundation pit retaining pile, use the soil or rock mass as the bearing layer, tie the front wing steel cage of the formwork on one side of the cap beam steel bar, and tie the rear wing steel cage of the formwork on the other side of the cap beam steel bar;

[0009] Concrete the crown beam, the front wing of the formwork and the rear wing of the formwork to form the formwork for the cantilevered member.

[0010] Optionally, when constructing the foundation pit retaining structure, longitudinal reinforcement is reserved at the top of the foundation pit retaining structure for anchoring with the cap beam.

[0011] In a second aspect, an embodiment of the present invention provides a cantilever member formwork construction method, comprising the following steps:

[0012] Before excavation of the foundation pit, the steel cage of the underground continuous wall is constructed;

[0013] With soil or rock mass as the bearing layer, the front wing steel cage of the formwork is tied on one side of the top of the steel cage of the underground continuous wall, and the rear wing steel cage of the formwork is tied on the other side of the steel cage of the underground continuous wall;

[0014] The underground continuous wall, the front wing of the formwork and the rear wing of the formwork are poured with concrete to form the formwork for the cantilevered element.

[0015] Optionally, the front wing steel bar cage includes a plurality of bottom steel bars and a plurality of top steel bars, and the bottom steel bars and the top steel bars are connected into a whole through stirrups.

[0016] Optionally, the rear wing steel bar cage includes a plurality of bottom steel bars and a plurality of top steel bars, and the bottom steel bars and the top steel bars are connected into a whole through stirrups.

[0017] Optionally, the front wing of the template is used as the cantilevered part of the cantilever member template, and its length is less than the length of the rear wing of the template.

[0018] Optionally, in the front wing and the rear wing, the corresponding top steel bars and bottom steel bars are a whole steel bar or the top steel bars and bottom steel bars of the front wing extend into the rear wing.

[0019] Optionally, the length of the rear wing is not less than twice the length of the front wing.

[0020] In a third aspect, an embodiment of the present invention provides a cantilever member construction method, comprising the following steps:

[0021] The cantilever member formwork is constructed using the construction method described in the first aspect or the second aspect;

[0022] Then the foundation pit is excavated;

[0023] Use the constructed cantilever component formwork to construct the cantilever components on the upper part of the foundation pit.

[0024] Optionally, cantilevered members above the front wing of the formwork and the rear wing of the formwork are constructed simultaneously.

[0025] Beneficial effects of the present invention:

[0026] 1. The formwork construction method of the present invention constructs the formwork before foundation pit excavation, uses soil or rock as the bearing layer, and erects the formwork steel cage and pours concrete. There is no need to erect scaffolding, supporting columns or diagonal braces inside the foundation pit, the work difficulty is small, the on-site workload is greatly reduced, the construction period is short, and the soil or rock is used as the bearing layer to ensure the casting quality of the formwork.

[0027] 2. The formwork construction method of the present invention sets up the steel cage of the formwork on site and pours concrete. The thickness can be determined according to the cantilever length of the cantilever construction of the upper cantilever structure bottom plate, and the scheme can be flexibly adjusted; the width direction is a non-stress direction, and the width size can be adjusted according to the needs of pouring the cantilever structure bottom plate.

[0028] 3. The template construction method of the present invention allows the template construction to be carried out simultaneously with the crown beam construction, thus shortening the construction period of the entire project.

[0029] 4. In the cantilever component construction method of the present invention, the cantilever component parts above the front wing of the formwork and the rear wing of the formwork are constructed synchronously, and the cantilever component parts on the rear wing of the formwork can be used to provide anti-overturning force, achieve self-balancing, and achieve stability during the reinforcement binding and concrete pouring of the cantilever component. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings in the specification, which constitute a part of the present application, are used to provide a further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute a limitation on the present application.

[0031] Figure 1 This is a schematic diagram of the method flow of Example 1 of the present invention;

[0032] Figure 2 This is a schematic diagram of the template structure constructed by the method of Example 1 of the present invention;

[0033] Among them, 1. bottom reinforcement, 2. top reinforcement, 3. stirrups, 4. front wing, 5. rear wing, 6. crown beam. DETAILED DESCRIPTION

[0034] Example 1

[0035] This embodiment provides a cantilever component formwork construction method, such as Figure 1-Figure 2 As shown, the following steps are included:

[0036] Step 1: Before excavating the foundation pit, construct retaining piles. The retaining piles are set along the edge of the foundation pit. The construction method of the retaining piles can adopt the existing construction method, and its specific construction method is not described in detail here.

[0037] During the construction of the retaining piles, longitudinal reinforcement extending to the top of the retaining piles is reserved at the top of the retaining piles for anchoring the retaining piles to the cap beam 6 arranged at the top thereof.

[0038] Step 2: Tie the steel cage of the crown beam on the top of the retaining pile. The steel cage of the crown beam 6 can adopt the existing structure. Excavate a part of the soil in advance at the position where the cantilever component formwork needs to be set up, and then tie the steel cage of the cantilever component formwork on the excavated soil part. The steel cage of the formwork and the steel cage of the crown beam are tied synchronously.

[0039] The steel cage of the formwork includes a front wing steel cage located on one side of the crown beam steel cage and a rear wing steel cage located on the other side of the crown beam steel cage. The front wing steel cage and the rear wing steel cage use soil or rock as the bearing layer or cushion layer and are tied synchronously with the steel cage of the crown beam.

[0040] Among them, the front wing steel bar cage includes a plurality of bottom steel bars 1 and a plurality of top steel bars 2 arranged in parallel, a plurality of stirrups 3 are arranged between the bottom steel bars 1 and the top steel bars 2, the stirrups 3 are arranged perpendicular to the bottom steel bars 1 and the top steel bars 2, and the two ends of the stirrups 3 are respectively tied and fixed to the bottom steel bars 1 and the top steel bars 2, and the stirrups 3 connect the bottom steel bars 1 and the top steel bars 2 into a whole to form a front wing steel bar cage.

[0041] Among them, the rear wing steel bar cage includes a plurality of bottom steel bars 1 and a plurality of top steel bars 2 arranged in parallel, a plurality of stirrups 3 are arranged between the bottom steel bars 1 and the top steel bars 2, the stirrups 3 are arranged perpendicular to the bottom steel bars 1 and the top steel bars 2, and the two ends of the stirrups 3 are respectively tied and fixed to the bottom steel bars and the top steel bars. The stirrups connect the bottom steel bars and the top steel bars into a whole to form the rear wing steel bar cage.

[0042] In this embodiment, the bottom steel bars 1 of the front wing steel cage and the bottom steel bars 1 of the rear wing steel cage are an integral steel bar, the top steel bars of the front wing steel cage and the top steel bars 2 of the rear wing steel cage are an integral steel bar, one top steel bar 2 serves as both the top steel bar of the front wing and the top steel bar of the rear wing, and one bottom steel bar 1 serves as both the bottom steel bar of the front wing and the bottom steel bar of the rear wing, so that after the rear wing is cast, the top steel bars and the bottom steel bars can anchor the front wing.

[0043] In another embodiment, the top steel bars 2 and the bottom steel bars 1 of the front wing steel cage pass through the steel cage of the crown beam and extend into the rear wing steel cage. After pouring concrete, the rear wing can be used to anchor the front wing.

[0044] Step 3: After the steel cages of the crown beam 6 and the front wing and rear wing are tied, concrete is poured to form the crown beam 6, the front wing 4 and the rear wing 5. The crown beam 6, the front wing 4 and the rear wing 5 are all reinforced concrete structures, which together form the cantilever component formwork. The steel cages of the crown beam 6 and the front wing 4 and the rear wing 5 are tied and poured at the same time, which shortens the construction period of the entire project.

[0045] By adopting the construction method of this embodiment, soil or rock is used as the bearing layer to erect the formwork steel cage and pour concrete. There is no need to erect scaffolding, supporting columns or diagonal braces inside the foundation pit. The work difficulty is small and the on-site workload is greatly reduced. In addition, using soil or rock as the bearing layer can ensure the casting quality of the formwork.

[0046] Moreover, the steel cage of the formwork is set up on site and concrete is poured. The thickness can be determined according to the cantilever length of the cantilever construction of the upper cantilever structure base plate, and the plan can be flexibly adjusted. The width direction is the non-stress direction, and the width size can be adjusted according to the needs of pouring the cantilever structure base plate.

[0047] In this embodiment, the front wing 4 is the cantilevered part of the template, and its length A is less than that of the rear wing. The length of the front wing 4 is determined according to the construction requirements of the cantilevered member bottom plate. By setting the rear wing 5, the entire template can reach a self-balanced state during the construction process. The length of the rear wing 5 is not less than twice the length of the front wing, that is, the length B of the rear wing 5 is not less than 2A, so as to meet the requirements of the anchorage length of the cantilevered steel bars of the front wing 4. The corresponding steel cage size can be set according to the size of the front wing 4 and the rear wing 5.

[0048] Example 2

[0049] This embodiment provides a cantilever component formwork construction method, comprising the following steps:

[0050] Step 1: Before excavating the foundation pit, the steel cage of the underground continuous wall is tied. The construction method can adopt the existing construction method, and the specific method and steps are not described in detail here.

[0051] Step 2: Excavate a portion of the soil at the location in the soil where the cantilever component formwork needs to be set, and then tie the steel cage of the front wing 4 of the cantilever component formwork on one side of the top of the underground continuous wall steel cage, and tie the steel cage of the rear wing 5 of the cantilever component formwork on the other side of the top of the underground continuous wall steel cage.

[0052] The setting method of the front wing steel cage and the rear wing steel cage is the same as that in Example 1, and will not be repeated here. The corresponding top steel bars of the front wing steel cage and the rear wing steel cage are one steel bar, the corresponding bottom steel bars are one steel bar, or the top steel bars and the bottom steel bars of the front wing steel cage extend into the rear wing steel cage.

[0053] Step 3: After the reinforcement cages of the front wing and the rear wing of the formwork for the cantilever member are tied up, concrete pouring is carried out, and the front wing 4, the rear wing 5 of the formwork and the diaphragm wall are poured simultaneously. After the pouring is completed, the top of the diaphragm wall, the front wing 4 and the rear wing 5 together form the formwork for the cantilever member.

[0054] In Embodiment 1 and Embodiment 2, the requirement for the concrete material used for pouring shall not be lower than C30, and the steel bars used for tying the reinforcement cages are HRB400 grade steel bars. It can be understood that those skilled in the art can select the specifications of the concrete material and the steel bars according to actual needs.

[0055] In Embodiment 1 and Embodiment 2, the front wing 4 and the rear wing 5 have the same thickness, and their top surfaces are flush with the top surface of the capping beam 6 or the top surface of the diaphragm wall. The thickness is determined according to the overhanging length of the front wing 4 into the foundation pit. The thickness value can refer to the structural requirements of the cantilever structural beam and at the same time meet the bearing capacity requirements of the formwork.

[0056] The requirements for the flatness, maximum deflection, etc. of the formwork meet the needs of the main structure of the upper cantilever member. The foundation pit, the calculated load of the formwork only considers the construction load of the upper main structure. When the main structure reaches the strength, the formwork no longer bears the external load.

[0057] Embodiment 3

[0058] This embodiment provides a construction method for a cantilever member, including the following steps:

[0059] Step 1: Construct the formwork for the cantilever member by using the method described in Embodiment 1 or Embodiment 2.

[0060] Step 2: Excavate the foundation pit so that the front wing forms a cantilever structure.

[0061] Step 3: Construct the cantilever member on the formwork.

[0062] When constructing the cantilever member, the cantilever member parts above the front wing 4 and the rear wing 5 are constructed synchronously, including synchronously tying the steel bars and synchronously pouring the concrete, so that the cantilever member part above the rear wing 5 plays an anti-overturning role, realizing the self-balancing of the formwork and achieving the stability during the tying of the bottom steel bars and the pouring of the concrete of the cantilever member structure.

[0063] Although the specific embodiments of the present invention are described above in conjunction with the drawings, it is not a limitation to the protection scope of the present invention. Those skilled in the art should understand that based on the technical solutions of the present invention, various modifications or deformations that can be made by those skilled in the art without creative efforts are still within the protection scope of the present invention.

Claims

1. A cantilever component formwork construction method, It is characterized in that The following steps are involved: Before excavating the foundation pit, construct the foundation pit retaining piles; Tie the steel cage of the cap beam on the top of the foundation pit retaining pile; use the soil or rock mass as the bearing layer, tie the front wing steel cage of the formwork on one side of the cap beam steel bar, and tie the rear wing steel cage of the formwork on the other side of the cap beam steel bar; Concrete the crown beam, the front wing of the formwork and the rear wing of the formwork to form the formwork for the cantilevered member; When constructing the foundation pit retaining structure, reserve longitudinal reinforcement at the top of the foundation pit retaining structure for anchoring with the crown beam; The formwork is constructed before the foundation pit is excavated, and the soil or rock mass is used as the bearing layer to set up the formwork steel cage and pour concrete. There is no need to set up scaffolding, supporting columns or diagonal braces inside the foundation pit; The cantilevered components above the front wing and the rear wing of the formwork are constructed simultaneously, and the cantilevered components on the rear wing of the formwork are used to provide anti-overturning force to achieve self-balancing and achieve stability during the reinforcement binding and concrete pouring of the cantilevered components.

2. A cantilever component formwork construction method, It is characterized in that The following steps are involved: Before excavation of the foundation pit, the steel cage of the underground continuous wall is constructed; With soil or rock mass as the bearing layer, the front wing steel cage of the formwork is tied on one side of the top of the steel cage of the underground continuous wall, and the rear wing steel cage of the formwork is tied on the other side of the steel cage of the underground continuous wall; Concrete the underground continuous wall, the front wing of the formwork and the rear wing of the formwork to form the formwork for the cantilevered member; When constructing the foundation pit retaining structure, longitudinal reinforcement is reserved at the top of the foundation pit retaining structure for anchoring with the crown beam; The formwork is constructed before the foundation pit is excavated, and the soil or rock mass is used as the bearing layer to set up the formwork steel cage and pour concrete. There is no need to set up scaffolding, supporting columns or diagonal braces inside the foundation pit; The cantilevered components above the front wing and the rear wing of the formwork are constructed simultaneously, and the cantilevered components on the rear wing of the formwork are used to provide anti-overturning force to achieve self-balancing and achieve stability during the reinforcement binding and concrete pouring of the cantilevered components.

3. A cantilever member formwork construction method as claimed in claim 1 or 2, It is characterized in that The front wing steel bar cage comprises a plurality of bottom steel bars and a plurality of top steel bars, and the bottom steel bars and the top steel bars are connected into a whole through stirrups.

4. A cantilever member formwork construction method as claimed in claim 1 or 2, It is characterized in that The rear wing steel bar cage comprises a plurality of bottom steel bars and a plurality of top steel bars, and the bottom steel bars and the top steel bars are connected into a whole through stirrups.

5. A cantilever member formwork construction method as claimed in claim 1 or 2, It is characterized in that The front wing of the template is used as the cantilevered part of the cantilever member template, and its length is shorter than the length of the rear wing of the template.

6. A cantilever member formwork construction method as claimed in claim 5, It is characterized in that In the front wing and the rear wing, the corresponding top reinforcement and bottom reinforcement are a whole reinforcement or the top reinforcement and bottom reinforcement of the front wing extend into the rear wing.

7. A cantilever member formwork construction method as claimed in claim 6, It is characterized in that The length of the rear wing is not less than twice the length of the front wing.

8. A cantilever member construction method, It is characterized in that The following steps are involved: The cantilever member formwork is constructed using the construction method described in claim 1 or claim 2; Then the foundation pit is excavated; Use the constructed cantilever component formwork to construct the cantilever components on the upper part of the foundation pit.

9. A cantilever member construction method as claimed in claim 8, It is characterized in that The cantilevered components above the front wing of the formwork and the rear wing of the formwork are constructed simultaneously.

Images