Connecting node structure of foundation pit bottom plate and temporary partition wall and construction method thereof

Abstract

This invention discloses a connection node structure and construction method for a foundation pit floor slab and a temporary partition wall. A corbel layer and a force-transfer layer are formed on the foundation floor slab on both sides of the temporary partition wall for force transmission. A backfill space is formed between the force-transfer layer, the corbel layer, and the temporary partition layer to store debris after the temporary partition wall is removed, preventing the temporary partition wall from cutting off the debris for transport, improving construction efficiency and reducing construction costs. After the temporary partition wall is removed within the foundation floor slab area, the cut debris is leveled, a post-cast cushion layer is poured on top, and a second waterproof membrane is installed. The second waterproof membrane overlaps and interweaves with the first waterproof membrane in space, preventing discontinuity in the waterproof membrane installation of the foundation floor slab. Multiple waterproofing measures are adopted to ensure the waterproofing effect of the post-cast portion of the temporary partition wall. This invention solves the problem in existing foundation pit sub-pit construction where the waterproof membrane of the floor slab cannot be connected due to the installation of the partition wall.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, specifically to a connection node structure between the foundation pit bottom slab and the temporary partition wall and its construction method. Background Technology

[0002] Currently, foundation pits located next to subway tunnels are mostly constructed using a phased, multi-pit construction method. This method requires the installation of temporary partition walls within the foundation pit. The base slabs on both sides of the partition wall will be disconnected, the waterproof membrane of the base slabs cannot be connected, and the concrete cleaning is difficult after the partition wall within the base slab area is removed. Summary of the Invention

[0003] To overcome the shortcomings of existing technologies, a connection node structure and construction method for the foundation pit bottom slab and temporary partition wall are provided to solve the problem that the waterproof membrane of the bottom slab cannot be connected due to the setting of the partition wall in the existing foundation pit split construction.

[0004] To achieve the above objectives, a connection node structure between the foundation pit floor slab and the temporary partition wall is provided, comprising:

[0005] A foundation layer is poured first, and a sinking trench is formed at the bottom of the foundation pit. A temporary central partition wall is formed in the middle of the sinking trench. The foundation layer is poured at the bottom of the foundation pit and extends along the trench wall to the temporary central partition wall.

[0006] The first waterproof membrane is laid on the pre-cast subbase and overlaps the temporary partition wall;

[0007] A foundation slab is poured on the pre-cast pad layer. The foundation slab extends above the sinking trough and is spaced apart from the temporary partition wall. The foundation slab above the sinking trough extends down along the wall of the sinking trough to form a corbel layer. The bottom of the corbel layers on opposite sides of the temporary partition wall extends in opposite directions to form a force transmission layer. The force transmission layer is connected to the temporary partition wall. The temporary partition layer, the corbel layer, and the force transmission layer enclose a backfill space for backfilling the cut-off debris of the temporary partition wall.

[0008] The post-cast cushion layer is poured onto the cut-off temporary partition wall and the cut-off debris in the backfill space;

[0009] The second waterproof membrane is laid on the post-pouring cushion layer. The opposite sides of the second waterproof membrane overlap the foundation plates on the opposite sides of the temporary partition wall. The second waterproof membrane and the foundation plates on the opposite sides of the temporary partition wall enclose the post-pouring space.

[0010] The post-cast base slab is a foundation slab cast in the post-cast space and connected to the opposite sides of the temporary partition wall.

[0011] Furthermore, the temporary partition wall is equipped with force-transmitting ribs that pass through the force-transmitting layer and extend into the corbel layer.

[0012] Furthermore, the depth of the backfill space is half the depth of the post-pouring space.

[0013] Furthermore, the main reinforcement bars of the post-cast base slab are connected to the main reinforcement bars of the foundation base slab.

[0014] Furthermore, a waterstop plate is embedded in the first layer of the foundation slab facing the temporary partition wall.

[0015] Furthermore, end-capping reinforcement bars are embedded in the foundation slab and the corbel layer.

[0016] Furthermore, the top of the truncated temporary partition wall is flush with the top of the corbel layer.

[0017] Furthermore, a first expansion sealing strip is embedded between the bottom of the force transmission layer and the temporary central partition wall.

[0018] Furthermore, a second expansion waterstop strip is embedded between the bottom of the post-cast bottom and the foundation plate.

[0019] This invention provides a construction method for the connection node between the foundation pit bottom slab and the temporary partition wall, comprising the following steps:

[0020] A sinking trench is formed by excavating the bottom of the foundation pit on both sides of the temporary central partition wall in the foundation pit, so that the temporary central partition wall is set in the middle of the sinking trench.

[0021] A pre-cast cushion layer is poured at the bottom of the foundation pit, and the pre-cast cushion layer extends along the wall of the sinking trough to the temporary central partition wall;

[0022] A first waterproof membrane is laid on the pre-cast subbase, and the first waterproof membrane overlaps the temporary partition wall;

[0023] A foundation slab is cast on the pre-cast pad layer to form a foundation base slab. The foundation base slab extends above the sinking trough and is spaced apart from the temporary partition wall. The foundation base slab above the sinking trough extends down along the wall of the sinking trough to form a corbel layer. The bottom of the corbel layers on opposite sides of the temporary partition wall extends in opposite directions to form a force transmission layer. The force transmission layer is connected to the temporary partition wall, so that the temporary partition layer, the corbel layer, and the force transmission layer enclose a backfill space.

[0024] Cut off the temporary partition wall and backfill the cut-off debris into the backfill space to prevent the cut-off debris from being transported out.

[0025] A post-cast cushion layer is formed by pouring the cut-off debris in the temporary partition wall and the backfill space after the cut-off;

[0026] A second waterproof membrane is laid on the post-cast cushion layer. The opposite sides of the second waterproof membrane overlap the foundation slabs on the opposite sides of the temporary partition wall. The second waterproof membrane and the foundation slabs on the opposite sides of the temporary partition wall enclose the post-cast space.

[0027] A post-cast base slab is formed by casting in the post-cast space, and the post-cast base slab is connected to the foundation base slabs on both sides of the temporary partition wall to form a closed base slab.

[0028] The beneficial effects of this invention are as follows: the connection node structure between the foundation pit slab and the temporary partition wall forms a corbel layer and a force-transfer layer on the foundation slab on both sides of the temporary partition wall for force transmission. A backfill space is formed between the force-transfer layer, the corbel layer, and the temporary partition layer to store the debris after the temporary partition wall is removed, preventing the temporary partition wall from cutting off the debris for transport, improving construction efficiency, and reducing construction costs. After the temporary partition wall is removed within the foundation slab area, the cut debris is leveled, a post-cast cushion layer is poured on top, and a second waterproof membrane is installed. The second waterproof membrane overlaps and interweaves with the first waterproof membrane in space, avoiding discontinuous waterproof membrane installation on the foundation slab. Multiple waterproofing measures are employed to ensure the waterproofing effect of the post-cast portion of the temporary partition wall. Attached Figure Description

[0029] 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:

[0030] Figure 1 This is a structural diagram illustrating the connection node between the foundation pit bottom slab and the temporary partition wall in an embodiment of the present invention.

[0031] Figure 2 This is a schematic diagram of the joint between the first waterproof membrane and the temporary partition wall in an embodiment of the present invention.

[0032] Figure 3 This is a schematic diagram of the post-cast space after the temporary partition wall is cut off, according to an embodiment of the present invention.

[0033] Figure 4 This is a schematic diagram of the structure after the post-cast base plate is formed according to an embodiment of the present invention. Detailed Implementation

[0034] 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.

[0035] 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.

[0036] Reference Figures 1 to 4 As shown, the present invention provides a connection node structure between the foundation pit bottom slab and the temporary intermediate partition wall, including: a pre-cast cushion layer 1, a first waterproof membrane 2, a foundation bottom slab 3, a post-cast cushion layer 4, a second waterproof membrane 5, and a post-cast bottom slab 6.

[0037] Specifically, a sinking trench is formed at the bottom of the foundation pit. A temporary central partition wall 7 is formed in the middle of the sinking trench. A pre-cast foundation layer 1 is poured at the bottom of the foundation pit. The pre-cast foundation layer 1 extends along the trench wall to the temporary central partition wall 7.

[0038] The first waterproof membrane 2 is laid on the pre-cast subbase 1 and overlaps the temporary partition wall 7.

[0039] The foundation slab 3 is poured on the pre-cast cushion layer 1. The foundation slab 3 extends above the sinkhole and is spaced apart from the temporary partition wall 7. The width of the gap between the foundation slab and the temporary partition wall is equal to the thickness of the temporary partition wall. A waterstop 34 is embedded in the first layer of the foundation slab 3 facing the temporary partition wall 7.

[0040] The foundation slab 3 above the sinking trough extends down along the trough wall to form a corbel layer 31. The bottoms of the corbel layers 31 on opposite sides of the temporary partition wall 7 extend in opposite directions to form a force-transfer layer 32. The force-transfer layer 32 is connected to the temporary partition wall 7. The temporary partition layer, corbel layer 31, and force-transfer layer 32 enclose a backfill space a for backfilling the cut-off debris of the temporary partition wall 7.

[0041] As a preferred implementation, the depth of backfill space a is half the depth of post-pouring space b.

[0042] As a preferred implementation, end-capping reinforcement bars 35 are embedded in the foundation slab 3 and the corbel layer 31.

[0043] The post-cast cushion layer 4 is poured into the cut-off temporary partition wall 7 and the cut-off debris in the backfill space a.

[0044] As a preferred implementation, the top of the cut-off temporary partition wall 7 is flush with the top of the corbel layer 31.

[0045] The second waterproof membrane 5 is laid on the post-pouring subbase 4. The opposite sides of the second waterproof membrane 5 overlap the foundation slabs 3 on the opposite sides of the temporary partition wall 7. The second waterproof membrane 5 and the foundation slabs 3 on the opposite sides of the temporary partition wall 7 enclose the post-pouring space b.

[0046] The post-cast base slab 6 is formed in the post-cast space b. The post-cast base slab 6 is connected to the foundation base slab 3 on both sides of the temporary partition wall 7.

[0047] Specifically, the main reinforcement bars 61 of the post-cast base slab 6 are connected to the main reinforcement bars 33 of the foundation base slab 3. One end of the main reinforcement bars of the post-cast base slab is mechanically connected to the main reinforcement bars 33 of the foundation base slab 3, and the other end is welded to the main reinforcement bars 33 of the foundation base slab 3. The welding is single-sided welding with a welding length of 15d. Adjacent connections are staggered. After the reinforcement bars are connected, a higher grade of micro-expansion impermeable concrete is poured to solidify and form the post-cast base slab, so that the post-cast base slab and the foundation base slab form a closed base slab.

[0048] The temporary partition wall 7 is equipped with a force-transfer rib 71. The force-transfer rib 71 passes through the force-transfer layer 32 and extends into the corbel layer 31.

[0049] See Figure 2 As shown, a first expansion waterstop strip 8 is embedded between the bottom of the force transmission layer 32 and the temporary central partition wall 7.

[0050] See Figure 3 As shown, a second expansion waterstop strip 9 is embedded between the bottom of the post-cast bottom and the foundation plate 3.

[0051] In this embodiment, before pouring the pre-cast foundation layer, a sinking trench is excavated downwards from the bottom of the excavated foundation pit to form a sinking trench. Specifically, when the foundation pit is excavated to the bottom, the sinking trench is excavated at a 30° angle downwards near the temporary partition wall.

[0052] After the sinkhole is excavated to its designated position, a pre-cast foundation layer is poured. Once the foundation layer is poured and reaches its required strength, holes for the reinforcing bars in the load-bearing layer are drilled at the corresponding locations on the temporary partition wall using an electric drill. The holes are then cleaned of dust. Reinforcing bars are not installed immediately after drilling; they are installed after the first waterproof membrane and the first expansion waterstop strip are installed. After laying the first waterproof membrane, the first expansion waterstop strip is affixed to the junction of the load-bearing layer and the temporary partition wall.

[0053] After the first waterproof membrane and the first expansion waterstop strip are installed, the main reinforcement of the foundation and the end reinforcement of the corbel layer are constructed.

[0054] When pouring the foundation slab, the space for subsequent pouring is blocked, and a water-stop steel plate is installed in the middle of the foundation slab.

[0055] When removing the upper part of the temporary partition wall, the partition wall above the top surface of the foundation slab is removed. The partition wall within the area between the bottom and top surfaces of the foundation slab is manually broken down, and all the debris from the broken temporary partition wall is filled into the backfill space. After the temporary partition wall is completely removed, the construction joints on both sides of the foundation slab are chiseled, the chiseled concrete debris is leveled, a post-cast bedding layer is poured, and a second waterproof membrane is laid. A second expansion sealing strip is then attached at the inside corner.

[0056] Next, the main reinforcement bars of the post-cast foundation slab in the post-cast space are connected. One end of the main reinforcement bars of the post-cast foundation slab is mechanically connected, and the other end is welded. The welding is single-sided welding with a welding length of 15d. Adjacent connections are staggered. After the reinforcement bars are connected, a higher grade of micro-expansion impermeable concrete is poured to solidify and form the post-cast foundation slab, so that the post-cast foundation slab and the foundation slab form a closed foundation slab.

[0057] This invention provides a construction method for the connection node between the foundation pit bottom slab and the temporary partition wall, comprising the following steps:

[0058] S1: A sinking trench is formed by excavating the bottom of the foundation pit on both sides of the temporary central partition wall 7 in the foundation pit, so that the temporary central partition wall 7 is set in the middle of the sinking trench.

[0059] S2: Pour the pre-cast cushion layer 1 at the bottom of the foundation pit. The pre-cast cushion layer 1 extends along the wall of the sinking trench to the temporary central partition wall 7.

[0060] S3: Lay the first waterproof membrane 2 on the pre-cast cushion layer 1, and overlap the first waterproof membrane 2 with the temporary partition wall 7.

[0061] S4: A foundation slab 3 is formed by pouring on the pre-cast pad 1. The foundation slab 3 extends above the sinking trough and is separated from the temporary partition wall 7. The foundation slab 3 above the sinking trough extends down along the wall of the sinking trough to form a corbel layer 31. The bottom of the corbel layers 31 on opposite sides of the temporary partition wall 7 extends to form a force transmission layer 32. The force transmission layer 32 is connected to the temporary partition wall 7, so that the temporary partition layer, corbel layer 31, and force transmission layer 32 enclose and form a backfill space a.

[0062] S5: Cut off the temporary partition wall 7 and backfill the cut-off debris of the temporary partition wall 7 into the backfill space a to avoid the removal of the cut-off debris.

[0063] S6: The cut-off debris in the temporary partition wall 7 and backfill space a is poured to form the post-cast cushion layer 4.

[0064] S7: Lay the second waterproof membrane 5 on the post-pouring pad 4. The opposite sides of the second waterproof membrane 5 overlap the foundation slabs 3 on the opposite sides of the temporary partition wall 7. The second waterproof membrane 5 and the foundation slabs 3 on the opposite sides of the temporary partition wall 7 enclose the post-pouring space b.

[0065] S8: The post-cast base slab 6 is formed by casting in the post-cast space b. The post-cast base slab 6 is connected to the foundation base slabs 3 on both sides of the temporary partition wall 7 to form a closed base slab.

[0066] The connection node structure between the foundation pit floor slab and the temporary partition wall of the present invention forms a corbel layer and a force-transfer layer on the foundation floor slab on both sides of the temporary partition wall for force transmission of the floor slab. A backfill space is formed between the force-transfer layer, the corbel layer, and the temporary partition layer to store the debris after the temporary partition wall is removed, preventing the temporary partition wall from cutting off the debris for transportation, improving construction efficiency, and reducing construction costs.

[0067] In this invention, the corbel layer of the connection node between the foundation pit bottom slab and the temporary partition wall is constructed with force-transferring bars and end-capping bars.

[0068] An expansion seal strip is installed at the contact point between the corbel layer and the temporary partition wall for water sealing.

[0069] After chiseling away the temporary partition wall within the foundation slab area, the broken debris is leveled, a post-cast bedding layer is poured on top, and a second waterproof membrane is installed. A second expansion waterstop strip is installed at the inside corner for waterproofing. The second waterproof membrane overlaps and interweaves with the first waterproof membrane in space to avoid discontinuity in the waterproof membrane installation of the foundation slab.

[0070] The bottom slab reinforcement is connected by mechanical connection on one side and by welding on the other side.

[0071] Compared with existing technologies that require the complete removal of concrete debris after the demolition of temporary partition walls, which involves a large workload and is difficult to clean, the connection node structure between the foundation pit bottom slab and the temporary partition wall in this invention reduces the amount of cleaning work by setting a backfill space to accommodate and cut off the debris, thereby leaving the concrete debris of the demolished temporary partition wall below the foundation bottom slab. At the same time, multiple waterproofing measures are adopted to ensure the waterproofing effect of the post-cast part of the temporary partition wall.

[0072] 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 connection node structure between the foundation pit bottom slab and the temporary intermediate partition wall, characterized in that, include: A foundation layer is poured first, and a sinking trough is formed at the bottom of the foundation pit. A temporary central partition wall is formed in the middle of the sinking trough. The foundation layer is poured at the bottom of the foundation pit and extends along the wall of the sinking trough to the temporary central partition wall. The first waterproof membrane is laid on the pre-cast subbase and overlaps the temporary partition wall; A foundation slab is poured on the pre-cast cushion layer. The foundation slab extends above the sinking trough and is spaced apart from the temporary partition wall. The foundation slab above the sinking trough extends down along the wall of the sinking trough to form a corbel layer. The bottom of the corbel layers on opposite sides of the temporary partition wall extends in opposite directions to form a force transmission layer. The force transmission layer is connected to the temporary partition wall. The temporary partition wall, the corbel layer, and the force transmission layer enclose a backfill space for backfilling the cut-off debris of the temporary partition wall. The post-cast cushion layer is poured onto the cut-off temporary partition wall and the cut-off debris in the backfill space; The second waterproof membrane is laid on the post-pouring cushion layer. The opposite sides of the second waterproof membrane overlap the foundation plates on the opposite sides of the temporary partition wall. The second waterproof membrane and the foundation plates on the opposite sides of the temporary partition wall enclose the post-pouring space. The post-cast base slab is a foundation slab cast in the post-cast space and connected to the opposite sides of the temporary partition wall.

2. The connection node structure between the foundation pit bottom slab and the temporary partition wall according to claim 1, characterized in that, The temporary partition wall is equipped with force-transmitting ribs, which pass through the force-transmitting layer and extend into the corbel layer.

3. The connection node structure between the foundation pit bottom slab and the temporary partition wall according to claim 1, characterized in that, The depth of the backfill space is half the depth of the post-pouring space.

4. The connection node structure between the foundation pit bottom slab and the temporary partition wall according to claim 1, characterized in that, The main reinforcement bars of the post-cast base slab are connected to the main reinforcement bars of the foundation base slab.

5. The connection node structure between the foundation pit bottom slab and the temporary partition wall according to claim 4, characterized in that, A waterstop plate is embedded in the first layer of the foundation slab facing the temporary partition wall.

6. The connection node structure between the foundation pit bottom slab and the temporary partition wall according to claim 1, characterized in that, The foundation slab and the corbel layer are embedded with end-capping reinforcement bars.

7. The connection node structure between the foundation pit bottom slab and the temporary partition wall according to claim 1, characterized in that, The top of the truncated temporary partition wall is flush with the top of the corbel layer.

8. The connection node structure between the foundation pit bottom slab and the temporary partition wall according to claim 1, characterized in that, A first expansion sealing strip is embedded between the bottom of the force transmission layer and the temporary partition wall.

9. The connection node structure between the foundation pit bottom slab and the temporary partition wall according to claim 1, characterized in that, A second expansion waterstop strip is embedded between the bottom of the post-cast bottom and the foundation plate.

10. A construction method for the connection node structure between the foundation pit bottom slab and the temporary partition wall as described in any one of claims 1 to 9, characterized in that, Includes the following steps: A sinking trench is formed by excavating the bottom of the foundation pit on both sides of the temporary central partition wall in the foundation pit, so that the temporary central partition wall is set in the middle of the sinking trench; A pre-cast cushion layer is poured at the bottom of the foundation pit, and the pre-cast cushion layer extends along the wall of the sinking trough to the temporary central partition wall; A first waterproof membrane is laid on the pre-cast subbase, and the first waterproof membrane overlaps the temporary partition wall; A foundation slab is cast on the pre-cast pad layer to form a foundation base slab. The foundation base slab extends above the sinking trough and is spaced apart from the temporary partition wall. The foundation base slab above the sinking trough extends down along the wall of the sinking trough to form a corbel layer. The bottom of the corbel layers on opposite sides of the temporary partition wall extends in opposite directions to form a force transmission layer. The force transmission layer is connected to the temporary partition wall, so that the temporary partition wall, the corbel layer, and the force transmission layer enclose a backfill space. Cut off the temporary partition wall and backfill the cut-off debris into the backfill space to prevent the cut-off debris from being transported out. A post-cast cushion layer is formed by pouring the cut-off debris in the temporary partition wall and the backfill space after the cut-off; A second waterproof membrane is laid on the post-cast cushion layer. The opposite sides of the second waterproof membrane overlap the foundation slabs on the opposite sides of the temporary partition wall. The second waterproof membrane and the foundation slabs on the opposite sides of the temporary partition wall enclose the post-cast space. A post-cast base slab is formed by casting in the post-cast space, and the post-cast base slab is connected to the foundation base slabs on both sides of the temporary partition wall to form a closed base slab.

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