Pre-connection back-jacking-free construction method for beam plates on two sides of partition wall in pit division construction

Abstract

The invention provides an in-advance connection back-jacking-free construction method for beam plates on two sides of a pit construction partition wall, relates to the technical field of pit partition walls, and solves the problems of back jacking and support replacement of the beam plates on the two sides of the partition wall by dismantling partial areas of the partition wall in advance and connecting the beam plates on the two sides of the partition wall under the condition of connecting partial beam plates on the two sides of the partition wall in advance. The construction progress and safety are guaranteed; and the cost is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of foundation pit partition walls, and specifically to a construction method for connecting the beam-slab on both sides of the partition wall in advance during separate pit construction without the need for back propping. Background Art

[0002] With the development of the economy, the urbanization process, the shortage of land resources, and the full utilization of underground space, there are more and more projects for large foundation pit construction and subway co-construction projects. Considering the geological conditions and the safety of subway lines, and ensuring the safety of the foundation pit, the foundation pits of these projects will be divided into two or more foundation pits.

[0003] After the construction of these foundation pit structures is completed, the retaining partition walls between the foundation pits need to be demolished. After demolition, the beam-slab on both sides of the retaining partition wall are connected to form an integral basement. Before the retaining partition wall is demolished, the beam-slab on both sides are in a cantilever state. Normally, back propping formwork supports are required to ensure that the structure does not deform or deflect. And when the beam-slab on both sides are not connected, the entire foundation pit cannot form an effective replacement strut, which has a greater impact on the safety of the foundation pit. Summary of the Invention

[0004] In view of the above-mentioned prior art, in order to accelerate the construction period, save construction costs, and facilitate basement construction, the present invention proposes a construction method for connecting the beam-slab on both sides of the partition wall in advance during separate pit construction without the need for back propping. Instead of using the traditional method of using steel pipes and wooden squares to reinforce the basement floor slabs on both sides of the partition wall, the present invention is convenient, fast, safe, reliable, economical, and environmentally friendly, and is applicable to large separate pit construction and subway isolation pit projects.

[0005] A construction method for connecting the beam-slab on both sides of the partition wall in advance during separate pit construction provided by the present invention includes the following steps: S1. For the foundation pit constructed first, the basement structure is constructed normally. A reinforced concrete corbel is set at the area where the basement beam-slab of the foundation pit constructed first intersects with the retaining partition wall for connection with the retaining partition wall; S2. Straight thread sleeves are installed on the contact surface between the basement beam-slab of the foundation pit constructed first and the retaining partition wall through structural steel bars. The other end of the straight thread sleeve is sealed with tape to prevent the straight thread sleeve from being blocked by concrete pouring; S3. Combining the beam-slab drawings and the retaining drawings, the area position where the retaining partition wall and the beam-slab are connected in advance is deepened. According to the drawings, measurement and setting out are carried out, and the control lines of the area where the beam-slab are connected in advance are set out on both sides of the retaining partition wall; S4. When the foundation pit constructed later is under construction, a part of the retaining partition wall that needs to be connected in advance for the beam-slab is demolished in advance, holes are opened in the retaining partition wall, and the corresponding positions are demolished, leaving holes for the beam-slab to be connected in advance; S5. The basement beam-slab of the foundation pit constructed later are connected to the straight thread sleeves in advance through the openings, and the steel bars are tied, the formwork is supported, and the concrete is poured. S6. After the construction of the foundation pit structure to be constructed later is completed and the connection of the beam-slab on both sides of the maintenance partition wall is completed, start demolishing the remaining maintenance partition wall structure; S7. After the demolition of the maintenance partition wall is completed, complete the connection and binding of the remaining unconnected beam-slab steel bars, set up the formwork support system, pour concrete, and complete the construction of the basement structure.

[0006] Preferably, in S1, the steel bars of the reinforced concrete corbel are welded to the steel bars of the maintenance partition wall. The reinforced concrete corbel is arranged below the beam-slab of the basement constructed first, with the same width as the beam.

[0007] Preferably, in S4, drill holes in the maintenance partition wall through a water drill. The diameter of the holes is 100 mm, with 4 cutting holes for each piece, and use a wire saw for cutting.

[0008] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a construction method for connecting the beam-slab on both sides of the partition wall in advance during pit construction without back-propping. The beam-slab in some areas on both sides of the basement maintenance partition wall is connected in advance, avoiding the back-propping of the floors on both sides of the partition wall due to cantilever, reducing the use of turnover materials, and saving labor and material costs. The beam-slab is connected in advance, avoiding pouring all the beam-slab to the maintenance edge, chiseling out the beam-slab steel bars, and re-setting up the formwork for construction. Connecting in advance saves the construction period and reduces the project cost. This method connects the beam-slab in advance, ensuring the early replacement of the strut of the foundation pit, and improving the safety and stability of the foundation pit. The present invention fully realizes a construction method adapted to local conditions. By using a wire saw to cut the partition wall to open holes in advance and connecting the beam-slab in advance, there is no need to chisel out the beam-slab concrete and connect the steel bars later. This construction method is green and environmentally friendly, without back-propping. In the later stage, the mechanical equipment can directly pass on the floor to demolish the maintenance wall, which is convenient, fast, safe, environmentally friendly, and cost-saving. Description of the Drawings

[0009] Figure 1 It is the plan view of the foundation pit constructed first in the embodiment of the present invention.

[0010] Figure 2 It is Figure 1 the a-a sectional view of

[0011] Figure 3 It is the plan view of the foundation pit constructed later in the embodiment of the present invention.

[0012] Figure 4 Figure 3 the b-b sectional view of

[0013] Figure 5 It is the plan view of the connection of the beam-slab on both sides of the maintenance partition wall in the embodiment of the present invention.

[0014] Figure 6 It is Figure 5 the c-c sectional view of

[0015] Figure 7 This is the plan view of the connection of the remaining beam-slab after the demolition of the enclosure partition wall in the embodiment of the present invention.

[0016] Figure 8 It is Figure 7 the d-d sectional view of

[0017] In the figure, 1. Enclosure partition wall; 2. Unexcavated foundation pit; 3. Cast structural slab; 4. Cast structural beam; 5. Cast frame column; 6. Structural steel bars; 7. Straight thread sleeve; 8. Opening for the demolition of the enclosure partition wall; 9. Uncast frame column; 10. Uncast structural slab; 11. Uncast structural beam; 12. Reinforced concrete corbel; 13. Opening; 14. Formwork support system. Specific implementation manner

[0018] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

[0019] Embodiment: As Figure 1-8 shown, a construction method for connecting the beam-slab on both sides of the partition wall in advance without back propping during pit excavation includes the following steps: S1. For the foundation pit constructed first, the basement structure is constructed normally. In the area where the beam-slab of the basement constructed first, which is the beam-slab that needs to be connected in advance, meets the enclosure partition wall 1, a reinforced concrete corbel 12 is set to connect with the enclosure partition wall 1. The steel bars of the reinforced concrete corbel 12 are welded to the steel bars of the enclosure partition wall 1. The reinforced concrete corbel 12 is set below the beam-slab of the basement constructed first, with the same width as the beam. S2. Straight thread sleeves 7 are installed on the contact surface between the beam-slab of the basement constructed first and the enclosure partition wall 1 through structural steel bars 6. The other end of the straight thread sleeve 7 is sealed with tape to prevent the straight thread sleeve 7 from being blocked by concrete pouring. S3. Combining the beam-slab drawings and the enclosure drawings, the position of the area where the enclosure partition wall 1 is connected with the beam-slab in advance is deepened. According to the drawings, measurement and setting out are carried out, and the control lines of the area where the beam-slab is connected in advance are set out on both sides of the enclosure partition wall 1. S4. When the foundation pit constructed later is under construction, a part of the enclosure partition wall 1 where the beam-slab needs to be connected in advance is demolished in advance. Holes are drilled in the enclosure partition wall 1 with a water drill. The diameter of the opening 13 is 100 mm, and there are 4 cutting holes for each piece. Rope saw cutting is used to demolish the corresponding position, leaving holes for the beam-slab to be connected in advance. S5. The beam-slab of the basement constructed later is connected with the straight thread sleeve 7 in advance through the opening 13, and the steel bars are tied, the formwork is installed, and the concrete is poured. S6. After the construction of the foundation pit structure constructed later is completed and the connection of the beam-slab on both sides of the enclosure partition wall 1 is completed, the remaining enclosure partition wall structure is demolished. After the demolition of the enclosure partition wall is completed, connect and tie the remaining unconnected beam and slab steel bars, erect the formwork support system 14, pour concrete, and complete the construction of the basement structure.

[0020] In this embodiment, when connecting some of the beams and slabs on both sides of the partition wall in advance, by demolishing some areas of the partition wall in advance and connecting the beams and slabs on both sides of the partition wall, the problems of falsework and replacement struts for the beams and slabs on both sides of the partition wall can be solved, ensuring the construction progress, safety and cost savings. This embodiment can effectively improve the related problems of floor construction after the partition wall is demolished, and further give play to the advantages of environmental protection, reduce the falsework of wooden formwork supports, reduce the pouring of the beams and slabs on both sides to the enclosure partition wall side. After the partition wall is demolished, chisel off the concrete of the beams and slabs on both sides, expose the steel bars for reconnection and pouring, reduce the external transportation of chiseled concrete waste, and use the method of connecting in advance to ensure the safety and reliability of construction. This embodiment fully realizes the construction design strategy of safety and adaptation to local conditions, reduces the project cost on the premise of ensuring safety, saves costs and protects the environment.

[0021] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent solutions made by using the content of the specification of the present invention, directly or indirectly applied in other related technical fields, are similarly within the patent protection scope of the present invention.

Claims

1. A construction method for pre-connecting beams and slabs on both sides of a partition wall in a pit construction without top-back, characterized in that: The steps include: S1. For the foundation pit constructed first, the basement structure is constructed normally. The area where the basement beam and slab constructed first meet the retaining partition wall is equipped with reinforced concrete brackets to connect with the retaining partition wall. S2. The contact surface between the pre-constructed basement beam and the enclosure partition wall is installed with a straight thread sleeve through the structural steel bar, and the other end of the straight thread sleeve is sealed with tape to prevent the straight thread sleeve from being blocked by concrete pouring; S3. Combine the beam-slab drawings and enclosure drawings to deepen the location of the area where the enclosure partition wall and the beam-slab are connected in advance, measure and lay out the lines according to the drawings, and lay out the area control lines for the beam-slab connection in advance on both sides of the enclosure partition wall; S4. During the foundation pit construction, remove the part of the retaining partition wall that needs to be connected with the beam and slab in advance, make holes in the retaining partition wall, remove the corresponding positions, and reserve the holes for the beam and slab to be connected in advance; S5. The basement beams and slabs to be constructed later are connected with straight thread sleeves in advance through opening holes, steel bars are tied to formwork, and concrete is poured; S6. After the foundation pit structure to be constructed is completed and the beams and slabs on both sides of the maintenance partition wall are connected, the remaining enclosure partition wall structure will be dismantled; S7. After the removal of the retaining partition wall, the remaining unconnected beam and slab reinforcements are connected and tied, the formwork system is set up, concrete is poured, and the basement structure construction is completed.

2. The method for pre-connecting beams and slabs on both sides of the partition wall constructed by pit construction as claimed in claim 1 is characterized in that: In S1, the steel bars of the reinforced concrete corbel are welded to the steel bars of the enclosing partition wall, and the reinforced concrete corbel is set below the basement beam slab constructed in advance, with the same width as the beam.

3. The method for pre-connecting beams and slabs on both sides of a partition wall constructed by split pits as described in claim 1 or 2, characterized in that: In S4, holes were drilled in the enclosure partition wall with a diameter of 100 mm, 4 holes were cut in each block, and a rope saw was used for cutting.

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