Foundation pit partition wall support changing construction method

Abstract

The invention discloses a foundation pit partition wall support changing construction method and relates to the field of building construction. According to the foundation pit partition wall support changing construction method, a cast-in-situ bored pile internally provided with a steel pipe column is constructed to replace a concrete pile, a support changing surrounding purlin connected with the steel pipe column and an inner support connected with the support changing surrounding purlin are constructed in the first stage of excavation construction of a basement, and a raft of the first stage of the basement is connected with the steel pipe column to complete raft support changing. Connecting the steel pipe columns with structural main beams of the floor slab structures through I-shaped steel brackets when the floor slab structures in the first stage of the basement are constructed, and finally cutting and removing the steel pipe columns in each layer when the second stage of the basement is sequentially constructed from bottom to top. The stability and reliability of a stress structure formed by a basement beam-slab-column structure, a steel pipe column and an enclosing purlin in the construction process are improved, the dismantling difficulty is reduced, the dismantling period is shortened, and the problems that the number of concrete temporary supporting components is large, the concrete dismantling difficulty is large, the construction period is long, the economic cost is large, and environmental friendliness is not achieved are solved. The problem that the first-stage structure cannot be closed if the second-stage structure of the basement is not developed is solved.

Description

Technical Field

[0001] The present application relates to the field of building construction, and in particular to a foundation pit partition wall support replacement construction method. Background Art

[0002] For various reasons, existing building projects need to divide a plot of land into multiple phases for development. The first phase underground space and the second phase underground space are also constructed in phases. Therefore, it is necessary to set up a temporary middle partition wall between the first phase underground space and the second phase underground space. The temporary middle partition wall plays the role of isolation and also serves as a foundation pit support and retaining wall.

[0003] like Figure 1 、 Figure 2 、 Figure 3 and Figure 4 As shown, the traditional temporary middle partition wall construction method is to construct full-length bored cast-in-place piles 100 to form the middle partition wall. Before the internal support 120 of the first-phase foundation pit support is removed, a replacement purlin 130 and a support beam 140 are set between the basement floor structure 110 and the middle partition wall. After the replacement of the support is completed, the support is removed. The second-phase basement structure adopts the above method to complete the replacement of the support from bottom to top, and after the second-phase basement structure is topped off, the middle partition wall is removed layer by layer. Each time a layer of the middle partition wall is removed, the construction of the missing first and second-phase floor structures above it needs to be completed and the strength reaches 100% before the next layer of the middle partition wall can be removed. In this way, the floor structure 110 is filled up layer by layer from top to bottom, and the middle partition wall is removed layer by layer until the missing raft slab 150 is finally filled up. As a result, the construction period needs to be increased by 4-6 months, which seriously affects the scheduled commissioning of the basement.

[0004] At the same time, the aforementioned traditional method of replacing the central partition wall requires a construction joint between the basement floor structure and the central partition wall. Concrete replacement purlins 120 and temporary concrete support beams 140 are installed on the Phase I and Phase II sides of the central partition wall as force transmission structures. This results in the loss of the Phase I floor slab on the central partition wall if Phase II development is delayed, significantly reducing functionality and resulting in significant economic losses. Furthermore, the traditional method of removing the central partition wall involves removing it layer by layer from top to bottom, i.e., closing the B0 slab and removing the central partition wall between the B0 and B1 slabs until the raft slab is closed. This top-down removal makes concrete removal extremely difficult, coupled with the numerous temporary concrete support components, which significantly impacts the construction period, incurs significant economic costs, and is environmentally unfriendly. Traditional full-length bored piles also present significant challenges, requiring large amounts of concrete to be removed and making slag removal difficult.

[0005] Therefore, a foundation pit partition wall replacement support construction method with short construction period, low construction difficulty and cost, and environmental protection is needed. Summary of the Invention

[0006] The purpose of this application is to provide a foundation pit partition wall replacement support construction method, which improves the stability and reliability of the supporting structure during the construction process, solves the problem that the first phase structure cannot be closed if the second phase is not developed, reduces the demolition difficulty and speeds up the demolition period.

[0007] This application is implemented as follows: The present application provides a foundation pit partition wall replacement construction method, comprising the following steps: Step 1: construct bored cast-in-place piles with steel pipe columns inside to obtain the middle partition wall; Step 2: Carry out the first phase of excavation of the basement. Excavate from top to bottom to the floor structure of each floor, and then construct the replacement purlins connected to the steel pipe columns and the internal supports connected to the replacement purlins, until all the earthwork is excavated to the bottom of the raft slab; Step 3: Connect the raft slab of the first phase of the basement to the steel pipe columns to complete the raft slab support replacement; Step 4: Construct each floor structure of the first phase of the basement from bottom to top. During construction, connect the steel pipe columns to the sides of the main beams of the floor structure with multiple I-beam brackets, then cast the floor structure. After each floor structure is constructed, remove the corresponding internal support of the previous floor structure. Step 5: Repeat the methods of Step 2 to Step 4 to carry out earthwork excavation, internal support construction, raft slab replacement construction, floor structure construction of each floor except the top floor, and internal support removal construction of the second basement phase; Step 6: Remove the connection between the raft and the steel pipe column and the bottom steel pipe column to complete the raft structure; Step 7: After the raft slab reaches the designed strength, remove the steel columns of each layer except the top layer from bottom to top; Step 8: Remove the internal support of the top floor of the second basement phase, complete the top floor structure of the second basement phase and connect it with the top floor structure of the first basement phase; Step 9: Remove the top steel pipe column and pour concrete to complete the construction.

[0008] In some optional implementation schemes, the raft slab of the first basement phase is connected to the steel pipe columns through multiple steel force transmission devices to complete the raft slab support replacement.

[0009] In some optional implementation schemes, the steel pipe column is preset with a flange corresponding to the steel force transmission device and the I-beam corbel.

[0010] In some optional embodiments, a plurality of stiffening ribs are respectively connected between the steel pipe column and each flange.

[0011] In some optional implementation schemes, when constructing the replacement purlin connected to the steel pipe column, the main reinforcement of the purlin embedded in the replacement purlin is first welded to the flange, and then the replacement purlin is cast and constructed.

[0012] In some optional embodiments, the steel pipe column is surface cleaned before being connected to the steel force transmission device and the I-beam corbel.

[0013] In some optional implementation schemes, when constructing the floor structure, after connecting the I-beam corbels, the main beam reinforcement in the floor structure is fully welded to the I-beam corbels on both sides, and the outer wall of the steel pipe column is coated with a concrete isolation agent, and then the floor structure is poured.

[0014] In some optional implementation schemes, when dismantling the steel pipe column, the steel pipe column is cut into sections and then hoisted out of the foundation pit.

[0015] The beneficial effects of the present application are as follows: the foundation pit partition wall replacement support construction method provided by the present application replaces the original full-length concrete piles through bored cast-in-place piles with steel pipe columns in the construction, and constructs the replacement support purlins connected to the steel pipe columns and the internal supports connected to the replacement support purlins when excavating and constructing the first phase of the basement, and connects the raft slab of the first phase of the basement to the steel pipe columns to complete the raft slab replacement support. Subsequently, when constructing each floor slab structure of the first phase of the basement, the steel pipe columns are connected to the structural main beams of the floor slab structure through I-beam brackets, and finally, when constructing the second phase of the basement from bottom to top, the steel pipe columns of each layer are cut and removed respectively, thereby improving the stability and reliability of the force conduction structure formed by the beam-slab-column structure of the basement and the steel pipe columns and the purlins during the construction process, reducing the difficulty of demolition while speeding up the demolition period, solving the problems of many temporary concrete support components, great difficulty in concrete demolition, long construction period, high economic cost, and environmental pollution, and solving the problem that the structure of the first phase of the basement cannot be closed if the second phase of the basement is not developed. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 A schematic diagram of the structure of two sides of a temporary middle partition wall constructed in the prior art using two inner supports, a replacement support purlin and a support beam to support bored piles; Figure 2 A schematic diagram of the structure of two sides of a temporary partition wall constructed in the prior art using an inner support, a replacement support purlin, and a support beam to support bored piles; Figure 3 A structural diagram of the conventional temporary partition wall construction method for removing the internal supports at the top floor structure and the sub-top floor structure, replacing the supporting purlins and support beams, and constructing the top floor structure and the sub-top floor structure; Figure 4 This is a structural diagram of the construction of each floor structure in the existing temporary partition wall construction method; Figure 5 A schematic diagram of the process of the foundation pit partition wall replacement construction method provided in an embodiment of the present application; Figure 6 A schematic diagram of the structure of the foundation pit partition wall replacement support construction method provided in an embodiment of the present application, in which internal supports and replacement support purlins are used to support both sides of the partition wall and a steel force transmission device is used to connect the raft slab replacement support; Figure 7 A schematic diagram of the structure when the steel force transmission device and the bottom steel pipe column are removed in the foundation pit partition wall replacement construction method provided in an embodiment of the present application; Figure 8 This is a schematic diagram of the structure when the topmost steel pipe column is not removed in the foundation pit partition wall replacement support construction method provided in an embodiment of the present application; Figure 9 A schematic diagram of the structure of the second-phase top floor structure of the basement in the foundation pit partition wall replacement support construction method provided in an embodiment of the present application; Figure 10 A schematic diagram of the structure when the topmost steel pipe column is removed in the foundation pit partition wall replacement support construction method provided in an embodiment of the present application; Figure 11 This is a structural schematic diagram of welding I-beam corbels during the construction of a floor slab structure in the foundation pit partition wall replacement support construction method provided in an embodiment of the present application.

[0018] In the figure: 100, bored cast-in-place piles; 110, floor structure; 111, structural main beam; 120, internal support; 130, exchangeable bracing purlin; 140, supporting beam; 150, raft slab; 160, steel pipe column; 170, flange; 180, stiffening rib; 190, I-beam corbel; 200, steel force transmission device. DETAILED DESCRIPTION

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0021] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0022] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of this application is typically placed when in use. These terms are intended only to facilitate the description of this application and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0023] Furthermore, terms such as "horizontal," "vertical," and "overhanging" do not necessarily imply that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0024] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0025] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0026] The features and performance of the foundation pit partition wall replacement construction method of the present application are further described in detail below in conjunction with the embodiments.

[0027] like Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 and Figure 11 As shown, the embodiment of the present application provides a foundation pit partition wall replacement construction method, comprising the following steps: Step 1: construct bored piles 100 with steel pipe columns 160 inside to obtain a middle partition wall; The drilling positions of the bored piles 100 of the middle partition wall are obtained by measurement and layout, a pile position is set at the position opposite the main structural beam 111 of the basement, and the steel pipe column 160 is pre-processed. The flange 170 and the stiffening ribs 180 connecting the steel pipe column 160 and the flange 170 are welded and fixed in advance on the outer wall of the steel pipe column 160 according to the design elevation.

[0028] During construction, bored cast-in-place piles 100 and embedded steel pipe columns 160 are used to form a pile retaining wall as the middle partition wall. Specifically, the drilling rig is in place to complete the hole drilling. First, the steel cage is lowered to the hole mouth, and then the steel pipe column 160 is hoisted and the verticality is corrected. The steel pipe column 160 and the steel cage are firmly welded with steel bars and then placed to the designed elevation again. The steel pipe column 160 is filled with concrete, and the entire middle partition wall is completed in this way.

[0029] Step 2: Carry out the first phase of excavation for the basement. After excavating from top to bottom to the top floor structure 110, remove the slurry on the outer wall of the steel pipe column 160 and the surface of the flange 170. After welding and fixing the main reinforcement of the purlin to the flange 170, construct the replacement purlin 130 connected to the steel pipe column 160. Then, further construct the inner support 120 connected to the replacement purlin 130. After the concrete strength reaches the design requirements, repeat the above steps until the earthwork of the floor structure 110 of each floor is completely excavated to the bottom of the raft 150. Step 3: rigidly connect the raft 150 of the first phase of the basement to the flange 170 on the steel column 160 through the spaced steel force transmission devices 200 to complete the raft 150 support replacement; Step 4: construct each floor structure 110 of the first phase of the basement from bottom to top. During construction, clean the surface of the flange 170 on the steel pipe column 160, weld the I-steel bracket 190 on the side of the steel pipe column 160 facing the main structural beam 111, and fully weld the main beam reinforcement in the main structural beam 111 to the I-steel bracket 190 on both sides. Except for the surface of the steel pipe column 160 connected to the main structural beam 111, apply concrete isolation agent on the other parts of the surface of the steel pipe column 160. Then cast the floor structure 110, connect the steel pipe column 160 to the side of the main structural beam 111 of the floor structure 110 with the I-steel bracket 190 arranged at intervals, and after completing the construction of each floor structure 110, remove the internal support 120 corresponding to the previous floor structure 110 to complete the replacement of the floor structure 110. Repeat this step until the construction of each floor structure 110 of the first phase of the basement, the replacement of the floor structure 110 and the removal of the internal support 120 are completed. Step 5: Repeat the methods of Step 2 to Step 4 to carry out earthwork excavation of each floor structure 110 of the second basement phase, construction of each internal support 120, replacement of the raft 150 support, construction of each floor structure 110 except the top floor structure 110, replacement of the floor structure 110 support, and removal of the internal support 120; Step 6: Remove the steel force transmission device 200 between the raft 150 and the steel pipe column 160, cut and remove the steel pipe column 160 between the raft 150 and the bottom floor structure 110, and complete the raft 150 structure; Step 7: After the raft 150 reaches the designed strength, cut and remove the steel pipe columns 160 between the floor structures 110 of each floor except the top floor from bottom to top. When removing the steel pipe columns 160, cut the steel pipe columns 160 into sections and then hoist them out of the foundation pit.

[0030] Step 8: Remove the inner support 120 of the top floor of the second basement phase, complete the top floor structure 110 of the second basement phase, and connect it with the top floor structure 110 of the first basement phase to form a whole; Step 9: Cut and remove the steel pipe column 160 between the top floor structure 110 and the second top floor structure 110 of the second phase of the basement, then pour concrete to complete the construction.

[0031] The foundation pit partition wall replacement construction method provided by the present application is to replace the original full-length concrete piles with bored cast-in-place piles 100 provided with steel pipe columns 160 as the middle partition wall, and to construct the replacement support purlin 130 connected to the steel pipe columns 160 and the inner support 120 connected to the replacement support purlin 130 during the excavation and construction of the first phase of the basement. The raft 150 of the first phase of the basement is connected to the steel pipe columns 160 to complete the replacement of the raft 150. Subsequently, when constructing each floor structure 110 of the first phase of the basement, the steel pipe columns 160 are connected to the main structure of the floor structure 110. Beam 111 is connected by I-steel bracket 190, and finally, when constructing the second phase of the basement from bottom to top, the steel pipe columns 160 of each layer are cut and removed respectively, which improves the stability and reliability of the load-transmitting structure formed by the basement beam-slab-column structure, steel pipe columns and purlins during construction, reduces the difficulty of demolition and speeds up the demolition period, solves the problems of many temporary concrete support components, difficult concrete demolition, long construction period, high economic cost and environmental pollution, and solves the problem that the structure of the first phase of the basement cannot be closed if the second phase of the basement is not developed.

[0032] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

Claims

1. A foundation pit partition wall replacement construction method, characterized in that: The following steps are involved: Step 1: construct bored cast-in-place piles with steel pipe columns inside to obtain the middle partition wall; Step 2: excavate the first phase of the basement, excavate from top to bottom to the floor structure of each floor, and then construct the replacement purlins connected to the steel pipe columns and the internal supports connected to the replacement purlins until all the earthwork is excavated to the bottom of the raft slab; Step 3: Connect the raft slab of the first phase of the basement to the steel pipe column to complete the raft slab support replacement; Step 4: construct the floor structures of the first phase of the basement from bottom to top. During construction, connect the steel pipe columns to the sides of the main beams of the floor structures with multiple I-steel brackets, then cast the floor structures. After each floor structure is constructed, remove the internal supports corresponding to the previous floor structure. Step 5: Repeat the methods of Step 2 to Step 4 to carry out earthwork excavation, internal support construction, raft slab replacement construction, floor structure construction of each floor except the top floor, and internal support removal construction of the second basement phase; Step 6: Remove the connection between the raft and the steel pipe columns and the bottom steel pipe columns to complete the raft structure; Step 7: After the raft slab reaches the designed strength, remove the steel columns of each layer except the top layer from bottom to top; Step 8: Remove the internal support of the top floor of the second basement phase, complete the top floor structure of the second basement phase and connect it with the top floor structure of the first basement phase; Step 9: Remove the top steel pipe column and pour concrete to complete the construction.

2. The foundation pit partition wall replacement construction method according to claim 1 is characterized in that: The raft slab of the first phase of the basement is connected to the steel pipe column through multiple steel force transmission devices to complete the raft slab support replacement.

3. The foundation pit partition wall replacement construction method according to claim 2 is characterized in that: The steel pipe column is preset with a flange corresponding to the steel force transmission device and the I-beam bracket.

4. The foundation pit partition wall replacement construction method according to claim 3 is characterized in that: A plurality of stiffening ribs are respectively connected between the steel pipe column and each flange.

5. The foundation pit partition wall replacement construction method according to claim 3 is characterized in that: When constructing the replacement purlin connected to the steel pipe column, firstly the main reinforcement of the purlin embedded in the replacement purlin is welded to the flange, and then the replacement purlin is cast and constructed.

6. The foundation pit partition wall replacement construction method according to claim 3 is characterized in that: The surface of the steel pipe column is cleaned before being connected to the steel section force transmission device and the I-beam corbel.

7. The foundation pit partition wall replacement construction method according to claim 1 is characterized in that: When constructing the floor structure, after connecting the I-steel bracket, the main beam steel bars in the floor structure are fully welded to the I-steel bracket on both sides, and the outer wall of the steel pipe column is coated with concrete isolation agent, and then the floor structure is poured.

8. The foundation pit partition wall replacement construction method according to claim 1 is characterized in that: When dismantling the steel pipe column, the steel pipe column is cut into sections and then hoisted out of the foundation pit.

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