Temporary lattice column passes through civil air defense roof back pouring sealing method

Abstract

The application discloses a kind of temporary lattice column and pass through the post-pouring sealing method of civil air defence roof, the lattice column inside pouring has filled concrete and forms steel concrete structure, post-pouring sealing method includes steps: setting the mould box of top open and bottom opening through hole, make lattice column pass through and form post-pouring space in through hole;Before pouring civil air defence roof, the filled concrete of corresponding area in lattice column is removed;Pouring civil air defence roof concrete, so that it fills the removed area in lattice column and is combined with lattice column;After underground structure construction is completed, mould box is removed and is cut off lattice column, so that cutting surface is located below the design elevation of civil air defence roof top;Pouring sealing concrete to post-pouring space, improve the connection reliability of lattice column and civil air defence roof by the above method, and promote the sealing and waterproof performance after lattice column is removed.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and in particular to a post-cast sealing method for temporary lattice columns penetrating the roof slab. Background Technology

[0002] During the construction of underground structures, temporary support systems are typically required to ensure the safety of foundation pit excavation and underground structure construction. Among these systems, lattice columns are commonly used vertical support components, employed in conjunction with horizontal support structures to bear the vertical loads during the construction phase.

[0003] In underground engineering projects involving the construction of civil defense roof slabs, when a lattice column passes through the civil defense roof slab, according to the relevant requirements for civil defense structure construction, it is necessary to pour and fill concrete inside the lattice column to form a steel-concrete structure to meet the structural performance requirements of the civil defense area.

[0004] In current construction processes, the roof slab of the civil defense shelter is usually poured directly after the lattice columns are installed, thus bonding the roof slab concrete with the external structure of the lattice columns. However, since the interior of the lattice columns is already filled with concrete, it is difficult for the roof slab concrete to penetrate into the interior of the lattice columns. As a result, the connection between the roof slab concrete and the lattice columns mainly relies on external contact, and the bond between the two is not tight enough, affecting the structural integrity at the location where the lattice columns are installed.

[0005] Meanwhile, after the underground structure construction is completed and the temporary support system is removed, it is usually necessary to cut and remove the lattice columns that penetrate the roof of the civil defense shelter. The existing construction method usually cuts the lattice columns along the surface of the roof of the civil defense shelter, resulting in the cut surface of the lattice columns being located near or even exposed on the surface of the roof of the civil defense shelter. It is difficult to fully cover the cut surface of the lattice columns during subsequent sealing treatment, which can easily lead to insufficient waterproof performance and affect the long-term reliability of the civil defense shelter roof. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a post-cast sealing method for temporary lattice columns penetrating the roof slab of civil defense structures. This method involves reserving post-cast space in a formwork, removing the concrete filling inside the lattice column, combining the concrete of the civil defense roof slab with the lattice column during casting, and subsequently cutting off the lattice column and casting a second time to seal it. This method achieves reliable waterproof sealing of the joint where the lattice column penetrates the roof slab of civil defense structures, ensuring the structural and functional requirements of the roof slab and improving construction efficiency.

[0007] To achieve the above objectives, the technical solution adopted in this invention is a post-cast sealing method for temporary lattice columns penetrating the roof slab of underground shelters. The lattice columns are internally filled with reinforced concrete to form a steel-concrete structure, serving as temporary support for the underground structure. The post-cast sealing method includes the following steps: Step 1: Set up a formwork box with an open top and a through hole at the corresponding position of the lattice column in the civil defense roof slab to be constructed, so that the lattice column passes through the through hole, and the bottom of the formwork box is within the thickness range of the civil defense roof slab, and the top is flush with the design elevation of the top of the civil defense roof slab, so as to form a post-pouring space in the formwork box; Step 2: Before pouring the concrete for the civil defense roof slab, remove the filling concrete in the lattice column located between the bottom of the formwork and the design elevation of the bottom of the civil defense roof slab; Step 3: Pour the concrete of the civil defense roof slab, so that the concrete of the civil defense roof slab fills the removed area inside the lattice column, so as to combine with the lattice column to form an integral structure; Step 4: After the underground structure construction is completed, remove the formwork and cut off the part of the lattice column located above the civil defense roof slab, so that the cut surface of the lattice column is below the design elevation of the top of the civil defense roof slab; Step 5: Pour sealing concrete into the post-cast space so that the sealing concrete covers the cut surface of the lattice column and combines with the roof slab of the civil defense structure.

[0008] A further improvement of the post-cast sealing method for temporary lattice columns penetrating the top slab of the civil defense shelter is that, before performing step 1 above, the reinforcing bars of the top slab of the civil defense shelter are tied, and when performing step 1 above, the reinforcing bars around the outer perimeter of the formwork are densified.

[0009] A further improvement of the post-cast sealing method for temporary lattice columns penetrating the top slab of the civil defense system is that, when performing step 1 above, the reinforcing bars of the top slab of the civil defense system pass through the formwork and extend into the post-cast space; when performing step 5 above, the reinforcing bars are tied in the post-cast space and overlapped with the reinforcing bars of the top slab of the civil defense system.

[0010] A further improvement of the post-cast sealing method for temporary lattice columns penetrating the roof slab of the present invention is that, when performing step 1 above, sealing mortar is filled into the gap between the through hole and the lattice column.

[0011] A further improvement of the post-cast sealing method for temporary lattice columns penetrating the roof slab of the present invention is that, after performing step 2 above and before performing step 3 above, a first water-stop steel plate is installed on the outer periphery of the chiseled section of the lattice column, and when performing step 3 above, the first water-stop steel plate is embedded in the concrete of the roof slab of the civil defense.

[0012] A further improvement of the post-cast sealing method for temporary lattice columns penetrating the roof slab of the present invention is that, when performing step 4 above, after removing the mold box, the surface of the post-cast space is roughened.

[0013] A further improvement of the post-cast sealing method for temporary lattice columns penetrating the roof slab of the present invention is that, after performing step 4 above and before performing step 5 above, a second water-stop steel plate is connected to the outer periphery of the cut surface of the lattice column, and when performing step 5 above, the second water-stop steel plate is embedded in the sealing concrete.

[0014] A further improvement of the post-cast sealing method for temporary lattice columns penetrating the roof slab of the present invention is that, when performing step 5 above, the sealing concrete is selected as micro-expansion concrete with a strength grade one higher than that of the roof slab concrete.

[0015] Compared with the prior art, the advantages of the present invention are: 1. By removing the concrete filling inside the lattice column and filling the removed area with concrete when pouring the civil defense roof slab, the concrete of the civil defense roof slab and the lattice column form an embedded bond from the inside out, overcoming the problem of loose bonding caused by the two relying only on external contact, and improving the overall integrity of the node structure. 2. By reserving space for post-pouring in the formwork and ensuring that the cut surface is below the design elevation of the civil defense roof when cutting the lattice column, and then fully covering the cut surface with post-pouring sealing concrete, the problem of insufficient sealing caused by exposed cut surface is avoided, thus ensuring the long-term waterproof reliability of the civil defense roof. 3. By increasing the reinforcement of the outer perimeter of the formwork, lapping the reinforcement of the civil defense roof slab into the post-cast space, and setting water-stop steel plates, the post-cast joints are integrated with the surrounding civil defense roof slabs, which improves the load-bearing capacity and impermeability of the joints. At the same time, the operation is simple and the construction efficiency is improved. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the post-cast joint between the lattice column and the roof slab of the civil defense structure according to the present invention.

[0018] In the diagram: 1. Lattice column; 2. Civil defense roof slab; 3. Formwork box; 4. Post-cast space; 5. First waterstop steel plate; 6. Second waterstop steel plate. Detailed Implementation

[0019] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0020] The following detailed description of the post-cast sealing method for temporary lattice columns penetrating the roof slab according to the present invention, with reference to the accompanying drawings and specific embodiments, will be provided in further detail.

[0021] Please see Figure 1 As shown, the post-cast sealing method for temporary lattice columns penetrating the roof slab of underground shelters involves pouring in filled concrete inside the lattice column 1 to form a reinforced concrete structure, serving as temporary support for the underground structure. This post-cast sealing method includes the following steps: Step 1: Set up a formwork 3 with an open top and a through hole at the location where the lattice column 1 passes through the top slab 2 to be constructed, so that the lattice column 1 passes through the through hole, and the bottom of the formwork 3 is within the thickness range of the top slab 2, and the top is flush with the top design elevation of the top slab 2, so as to form a post-pouring space 4 in the formwork 3; Step 2: Before pouring the concrete for the civil defense roof slab 2, remove the filling concrete inside the lattice column 1 located between the bottom of the formwork 3 and the bottom design elevation of the civil defense roof slab 2; Step 3: Pour concrete for the civil defense roof slab 2, so that the concrete for the civil defense roof slab 2 fills the removed area inside the lattice column 1, so as to combine with the lattice column 1 to form an integral structure; Step 4: After the underground structure construction is completed, remove the formwork 3 and cut off the part of the lattice column 1 located above the civil defense roof slab 2, so that the cut surface of the lattice column 1 is below the design elevation of the top of the civil defense roof slab 2. Step 5: Pour sealing concrete into the post-cast space 4 so that the sealing concrete covers the cut surface of the lattice column 1 and combines with the civil defense roof slab 2.

[0022] Specifically, such as Figure 1 As shown: H1 is the top design elevation of the civil defense roof slab 2, H2 is the bottom elevation of the formwork 3, and H3 is the bottom design elevation of the civil defense roof slab 2. When performing step 2 above, the filling concrete between H2 and H3 of the lattice column is removed.

[0023] Specifically, the bottom of the mold box 3 is controlled between the elevation of 1 / 3 of the thickness of the roof slab 2 and the elevation of 1 / 2 of the thickness of the roof slab 2.

[0024] By reasonably limiting the position of the bottom of the mold box 3, the mold box 3 forms a post-pouring space 4 of appropriate depth in the thickness direction of the civil defense roof slab 2. This avoids weakening the structural performance of the civil defense roof slab 2 due to the excessive depth of the post-pouring space 4, and also ensures that the cut surface of the lattice column 1 is within the coverage area of ​​the closed concrete, thereby improving the reliability of the post-pouring closed area.

[0025] Specifically, the outer periphery of the mold 3 is coated with a release agent.

[0026] By applying a release agent to the outer perimeter of the formwork 3, the adhesion between the formwork 3 and the surrounding concrete can be reduced, making it easier for the formwork 3 to detach from the concrete of the civil defense roof slab 2 during the demolding process. This avoids damage to the concrete around the post-cast space 4 during demolding, thereby ensuring the integrity of the subsequent closed concrete pouring area.

[0027] Specifically, when performing step 4 above, the cut surface of the lattice column 1 should be kept as far away as possible from the top design elevation of the fire-resistant roof slab 2.

[0028] By lowering the elevation of the cut surface of the lattice column 1, the residual portion of the lattice column 1 within the post-cast space 4 is shortened, thereby increasing the filling range of the sealing concrete within the post-cast space 4 and improving the overall bonding performance between the sealing concrete and the roof slab 2 of the civil defense structure.

[0029] Preferably, before performing step 1 above, the steel bars of the roof slab 2 are tied, and when performing step 1 above, the steel bars around the outer perimeter of the mold box 3 are densified.

[0030] By densifying the reinforcing bars around the outer perimeter of the formwork 3, the local changes in the arrangement of reinforcing bars caused by setting the formwork 3 can be compensated, the constraint capacity of the concrete structure around the post-cast space 4 can be improved, and the risk of cracks in the post-cast closed area can be reduced.

[0031] Preferably, when performing step 1 above, the reinforcing bars of the civil defense roof slab 2 pass through the formwork 3 and extend into the post-cast space 4. When performing step 5 above, the reinforcing bars are tied in the post-cast space 4 and overlapped with the reinforcing bars of the civil defense roof slab 2.

[0032] Specifically, the mold box 3 is provided with a clearance hole for the steel bars of the civil defense roof slab 2 to pass through. One end of the steel bar of the civil defense roof slab 2 passes through the clearance hole and extends into the post-cast space 4. Before pouring the sealing concrete, reinforcing steel bars are set according to the size of the post-cast space 4 and the reinforcing steel bars are connected to the steel bars of the civil defense roof slab 2 that extend into the post-cast space 4 to improve the connection strength between the sealing concrete and the civil defense roof slab 2.

[0033] Specifically, in order to facilitate the subsequent removal of the formwork 3, the reinforcing bars binding the civil defense roof slab 2 do not extend into the post-cast space 4. Instead, after the formwork 3 is removed, the post-cast space 4 is excavated to expose the reinforcing bars of the civil defense roof slab 2 so that they can overlap with the reinforcing bars in the post-cast space 4.

[0034] By ensuring that the reinforcing bars of the civil defense roof slab 2 do not extend into the post-cast space 4 during the binding of the reinforcing bars, interference between the reinforcing bars and the formwork 3 can be avoided, making it easier to dismantle the formwork 3 as a whole after the underground structure construction is completed. At the same time, after the formwork 3 is removed, the post-cast space 4 is excavated to expose the reinforcing bars of the civil defense roof slab 2 and overlap with the reinforcing bars subsequently installed in the post-cast space 4, thereby ensuring the reliability of the connection between the post-cast enclosed area and the civil defense roof slab 2.

[0035] Preferably, when performing step 1 above, the gap between the through hole and the lattice column 1 is filled with sealing mortar.

[0036] By filling the gap between the through hole and the lattice column 1 with sealing mortar, a sealed connection is formed between the bottom of the mold box 3 and the lattice column 1. This prevents concrete slurry from entering the post-pouring space 4 through the gap when the concrete of the civil defense roof slab 2 is poured, ensuring the integrity of the post-pouring space 4. This facilitates the subsequent removal of the lattice column 1 and the sealing pouring.

[0037] Preferably, after performing step 2 above and before performing step 3 above, a first water-stop steel plate 5 is installed on the outer periphery of the chiseled section of the lattice column 1. When performing step 3 above, the first water-stop steel plate 5 is embedded in the concrete of the civil defense roof slab 2.

[0038] By installing a first water-stop steel plate 5 on the outer periphery of the chiseled section of the lattice column 1 and embedding the first water-stop steel plate 5 in the concrete of the civil defense roof slab 2, a reliable connection is formed between the first water-stop steel plate 5 and the concrete of the civil defense roof slab. This extends the seepage path of water along the lattice column 1 and the civil defense roof slab, reduces the risk of groundwater leakage along the interface between the lattice column 1 and the concrete, and improves the waterproof performance of the civil defense roof slab at the location where the lattice column 1 is installed.

[0039] Specifically, the chiseled section of the lattice column 1 is also coated with waterproof paint.

[0040] By applying a waterproof coating to the chiseled section of the lattice column 1, the exposed surface of the lattice column 1 after chiseling can be protected, preventing the surface of the lattice column 1 from directly contacting external water bodies, and at the same time improving the waterproof performance of the area where the lattice column 1 is bonded to the concrete of the civil defense roof slab.

[0041] Preferably, when performing step 4 above, after removing the mold box 3, the surface of the post-pouring space 4 is roughened.

[0042] By roughening the surface of the post-cast space 4 after removing the formwork 3, the original civil defense roof concrete around the post-cast space 4 forms a rough bonding surface, increasing the contact area between the sealed concrete and the civil defense roof, improving the bonding performance between the old and new concrete, and thus enhancing the integrity of the post-cast sealed area.

[0043] Preferably, after performing step 4 above and before performing step 5 above, a second water-stop steel plate 6 is connected to the outer periphery of the cut surface of the lattice column 1, and when performing step 5 above, the second water-stop steel plate 6 is embedded in the closed concrete.

[0044] By setting a second water-stop steel plate 6 around the cut surface of the lattice column 1 and embedding the second water-stop steel plate 6 in the closed concrete, a multi-layer waterproof structure is formed in conjunction with the first water-stop steel plate 5, which can improve the waterproof reliability at the penetration location of the lattice column 1.

[0045] Preferably, when performing step 5 above, the sealing concrete is a micro-expansion concrete with a strength grade one grade higher than that of the civil defense roof concrete.

[0046] By using micro-expansion concrete with a strength grade one level higher than that of the civil defense roof slab concrete as the sealing concrete, the sealing concrete has higher structural strength, and the micro-expansion property reduces the gaps caused by hardening shrinkage, improving the filling density of the post-cast space 4, thereby enhancing the structural reliability of the post-cast sealed area.

[0047] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding and reading. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for post-cast sealing of temporary lattice columns penetrating the roof slab of underground shelters, wherein the interior of the lattice column is filled with reinforced concrete to form a reinforced concrete structure, serving as temporary support for the underground structure, characterized in that... The post-cast sealing method includes the following steps: Step 1: Set up a formwork box with an open top and a through hole at the corresponding position of the lattice column in the civil defense roof slab to be constructed, so that the lattice column passes through the through hole, and the bottom of the formwork box is within the thickness range of the civil defense roof slab, and the top is flush with the design elevation of the top of the civil defense roof slab, so as to form a post-pouring space in the formwork box; Step 2: Before pouring the concrete for the civil defense roof slab, remove the filling concrete in the lattice column located between the bottom of the formwork and the design elevation of the bottom of the civil defense roof slab; Step 3: Pour the concrete of the civil defense roof slab, so that the concrete of the civil defense roof slab fills the removed area inside the lattice column, so as to combine with the lattice column to form an integral structure; Step 4: After the underground structure construction is completed, remove the formwork and cut off the part of the lattice column located above the civil defense roof slab, so that the cut surface of the lattice column is below the design elevation of the top of the civil defense roof slab; Step 5: Pour sealing concrete into the post-cast space so that the sealing concrete covers the cut surface of the lattice column and combines with the roof slab of the civil defense structure.

2. The post-cast sealing method for temporary lattice columns penetrating the roof slab as described in claim 1, characterized in that, Before performing step 1 above, the steel bars of the civil defense roof slab are tied. When performing step 1 above, the steel bars around the outer perimeter of the mold box are densified.

3. The post-cast sealing method for temporary lattice columns penetrating the roof slab as described in claim 2, characterized in that, When performing step 1 above, the reinforcing bars of the civil defense roof slab pass through the formwork and extend into the post-cast space. When performing step 5 above, the reinforcing bars are tied in the post-cast space and overlapped with the reinforcing bars of the civil defense roof slab.

4. The post-cast sealing method for temporary lattice columns penetrating the roof slab as described in claim 1, characterized in that, When performing step 1 above, sealant mortar is filled into the gap between the through hole and the lattice column.

5. The post-cast sealing method for temporary lattice columns penetrating the roof slab as described in claim 1, characterized in that, After performing step 2 above and before performing step 3 above, a first water-stop steel plate is installed on the outer periphery of the chiseled section of the lattice column. When performing step 3 above, the first water-stop steel plate is embedded in the concrete of the civil defense roof slab.

6. The post-cast sealing method for temporary lattice columns penetrating the roof slab as described in claim 1, characterized in that, When performing step 4 above, after removing the mold box, the surface of the post-pouring space is roughened.

7. The post-cast sealing method for temporary lattice columns penetrating the roof slab as described in claim 1, characterized in that, After performing step 4 above and before performing step 5 above, a second water-stop steel plate is connected to the outer periphery of the cut surface of the lattice column. When performing step 5 above, the second water-stop steel plate is embedded in the closed concrete.

8. The post-cast sealing method for temporary lattice columns penetrating the roof slab as described in claim 1, characterized in that, When performing step 5 above, the sealing concrete is selected as micro-expansion concrete with a strength grade one higher than that of the civil defense roof concrete.

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