Foundation pit concrete enclosing purlin construction method

Abstract

The invention belongs to the technical field of underground engineering construction, and discloses a foundation pit concrete enclosing purlin construction method, which is characterized in that a supporting structure is welded on a vertical main reinforcement of an underground diaphragm wall to provide vertical support for an enclosing purlin template. One end of a pull rod penetrating through the enclosing purlin formwork is welded to the vertical main rib, the other end of the pull rod is fixed to the vertical supporting assembly through a limiting piece, a stress system of the horizontal pull rod is formed, deformation of the enclosing purlin formwork is prevented, and the stability of the enclosing purlin formwork is guaranteed. The hanging bars are connected between the enclosing purlin formwork and the vertical main bars, included angles are formed between the hanging bars and the vertical main bars, the dead weight of the enclosing purlin formwork can be transmitted to the vertical main bars of the underground diaphragm wall in combination with horizontal pulling force provided by the pull rods, and then the enclosing purlin formwork is stably fixed to one side of the underground diaphragm wall. A cushion layer does not need to be poured, the procedures of cushion layer pouring and breaking are reduced, high construction efficiency is achieved, and the construction period can be shortened easily.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of underground engineering construction, and in particular to a concrete coffering construction method for foundation pits. BACKGROUND

[0002] As a key link of underground building engineering, the reliability of the supporting system of a foundation pit engineering directly determines the safety and stability of the foundation pit body and surrounding buildings. As a core stressed component of the supporting system, the concrete coffering, through the coordinated work with vertical support structures such as row piles and underground continuous walls and internal supports, realizes the transmission and distribution of lateral earth pressure and water pressure, and is an indispensable key part in a deep foundation pit.

[0003] In the existing concrete coffering construction, a cushion layer + formwork is generally used, the cushion layer is poured above the soil layer after earthwork excavation, and after the cushion layer reaches a certain strength, the coffering formwork is erected on the cushion layer, and the cushion layer provides vertical support to the coffering formwork. However, with the increasing depth of the foundation pit, various construction facilities are added in the foundation pit to prevent deformation of the foundation pit, which makes it impossible to construct the cushion layer under the coffering, thereby making it impossible to carry out subsequent coffering construction.

[0004] Therefore, there is an urgent need for a concrete coffering construction method without the need to pour a cushion layer. SUMMARY

[0005] The present application aims to provide a concrete coffering construction method for a foundation pit, which does not need to pour a cushion layer under the coffering, has high construction efficiency, and is beneficial to shorten the construction period.

[0006] To achieve this purpose, the present application adopts the following technical solutions:

[0007] A concrete coffering construction method for a foundation pit is provided, comprising the following steps:

[0008] S1: installing a support structure;

[0009] Vertical main reinforcement corresponding to the coffering position of the underground continuous wall is chiseled out, the support structure comprises a horizontal support assembly and a vertical support assembly, the vertical support assembly is arranged at the first end of the horizontal support assembly, and the second end of the horizontal support assembly is welded to the vertical main reinforcement;

[0010] S2: installing a coffering formwork;

[0011] The coffering formwork is placed on the horizontal support assembly; a pull rod extending in the horizontal direction is arranged on the coffering formwork, one end of the pull rod is welded to the vertical main reinforcement, the other end of the pull rod is sleeved with a limiting piece, and the limiting piece abuts against the end face of the vertical support assembly away from the underground continuous wall;

[0012] S3: setting a hanging reinforcement;

[0013] The hanging bar is connected between the surrounding purlin template and the vertical main bar, and the hanging bar is arranged at an angle with the vertical main bar;

[0014] S4: pouring concrete surrounding purlin;

[0015] Pouring concrete into the surrounding purlin template.

[0016] As an optional solution of the foundation pit concrete surrounding purlin construction method, the support structure further comprises a horizontal cushion layer and a vertical cushion layer, the horizontal cushion layer is arranged between the horizontal support assembly and the surrounding purlin template, and the vertical cushion layer is arranged between the vertical support assembly and the surrounding purlin template.

[0017] As an optional solution of the foundation pit concrete surrounding purlin construction method, the horizontal cushion layer comprises a plurality of horizontal cushion rods arranged at intervals in the horizontal direction, and the vertical cushion layer comprises a plurality of vertical cushion rods arranged at intervals in the vertical direction.

[0018] As an optional solution of the foundation pit concrete surrounding purlin construction method, the horizontal cushion rod and the vertical cushion rod are both wooden.

[0019] As an optional solution of the foundation pit concrete surrounding purlin construction method, the horizontal cushion rod and the vertical cushion rod are both bound and fixed to the surrounding purlin template.

[0020] As an optional solution of the foundation pit concrete surrounding purlin construction method, the second end of the hanging bar is connected with a reinforcing bar, the reinforcing bar extends in the horizontal direction, and the end of the reinforcing bar away from the hanging bar is implanted into the underground continuous wall.

[0021] As an optional solution of the foundation pit concrete surrounding purlin construction method, the angle α between the hanging bar and the vertical main bar ranges from 20° to 45°.

[0022] As an optional solution of the foundation pit concrete surrounding purlin construction method, a connecting bar is planted on the underground continuous wall, and the horizontal support assembly is fixed to the end of the connecting bar.

[0023] As an optional solution of the foundation pit concrete surrounding purlin construction method, a plurality of the pull rods are arranged at intervals in the vertical direction.

[0024] As an optional solution of the foundation pit concrete surrounding purlin construction method, a plurality of the hanging bars are arranged.

[0025] The beneficial effects of the present application are as follows:

[0026] The application provides a foundation pit concrete enclosing purlin construction method, which provides vertical support for the enclosing purlin template by welding a support structure on the vertical main reinforcement of the underground continuous wall. One end of the pull rod penetrating the enclosing purlin template is welded on the vertical main reinforcement, and the other end is fixed on the vertical support assembly through a limiting piece, forming a stress system of the horizontal pull rod, preventing the deformation of the enclosing purlin template and ensuring the stability of the enclosing purlin template. The hanging reinforcement is connected between the enclosing purlin template and the vertical main reinforcement and is arranged at an angle with the vertical main reinforcement. In combination with the horizontal pulling force provided by the pull rod, the self-weight of the enclosing purlin template can be transmitted to the vertical main reinforcement of the underground continuous wall, and then the enclosing purlin template is stably fixed on one side of the underground continuous wall. Without pouring the cushion layer, the process of pouring and breaking the cushion layer is reduced, the construction efficiency is high, and the construction period is shortened. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a cross-sectional view of the enclosing purlin construction process provided by the embodiment of the specific embodiment of the application;

[0028] Figure 2 is a partial structure schematic view of the enclosing purlin construction process provided by the embodiment of the specific embodiment of the application.

[0029] In the drawings:

[0030] 100, underground continuous wall; 101, vertical main reinforcement; 102, connecting reinforcement; 200, movable steel support platform; 300, axial force equipment; 400, support pile;

[0031] 1, support structure; 11, horizontal support assembly; 12, vertical support assembly; 13, horizontal cushion layer; 131, horizontal cushion rod; 14, vertical cushion layer; 141, vertical cushion rod;

[0032] 2, enclosing purlin template; 21, pull rod; 22, limiting piece;

[0033] 3, hanging reinforcement; 4, reinforcing reinforcement. DETAILED DESCRIPTION

[0034] The embodiments of the application are described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals represent the same or similar parts or parts having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the application, and cannot be understood as a limitation of the application.

[0035] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0036] In the description of the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can include that the first feature and the second feature are in direct contact, or that the first feature and the second feature are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0037] The technical scheme of the present application will be further illustrated below in conjunction with the drawings and through specific embodiments.

[0038] In the process of deep foundation pit construction, transverse support beams are set to prevent foundation pit deformation and ensure the safety and stability of the foundation pit body and surrounding buildings. Figure 1 and Figure 2 As shown in the drawings, a movable steel support platform 200 capable of moving vertically is arranged in the foundation pit and abuts against the upper end surface of the support pile 400. The end of the movable steel support platform 200 is provided with an axial force device 300, which abuts against the underground continuous wall 100. A surrounding purlin needs to be arranged above the axial force device 300, but the axial force device 300 cannot provide vertical support force for the surrounding purlin formwork 2, and it is impossible to pour a cushion layer on the side of the foundation pit bottom according to the existing scheme. In order to ensure the smooth construction of the surrounding purlin, the present embodiment provides a foundation pit concrete surrounding purlin construction method.

[0039] The method comprises the following steps:

[0040] S1: installing a support structure 1;

[0041] The vertical main reinforcement 101 corresponding to the position of the surrounding purlin of the underground continuous wall 100 is chiseled out, the support structure 1 comprises a horizontal support assembly 11 and a vertical support assembly 12, the vertical support assembly 12 is arranged at the first end of the horizontal support assembly 11, and the second end of the horizontal support assembly 11 is welded to the vertical main reinforcement 101.

[0042] The above step, in the embodiment, the vertical main reinforcement 101 corresponding to the position of the surrounding purlin of the underground continuous wall 100 is chiseled, and the second end of the horizontal support assembly 11 is welded on the vertical main reinforcement 101.

[0043] Specifically, the horizontal support assembly 11 and the vertical support assembly 12 are both steel pipes, which have high strength-weight ratio, light weight and strong carrying capacity, good toughness and ductility, and high structural safety. At the same time, the steel pipe has good economy, which is conducive to reducing construction cost.

[0044] Optionally, the connecting reinforcement 102 is planted on the underground continuous wall 100, and the horizontal support assembly 11 is fixed to the end of the connecting reinforcement 102. Specifically, the connecting reinforcement 102 extends out of the end of the underground continuous wall 100 to the horizontal support assembly 11, and the connecting reinforcement 102 provides accurate positioning reference and reliable temporary support for the arrangement of the horizontal support assembly 11. When installing the horizontal support assembly 11, the horizontal support assembly 11 is sleeved on the end of the connecting reinforcement 102, which can realize the initial positioning of the horizontal support assembly 11, and then the operator welds the horizontal support assembly 11 on the main reinforcement of the underground continuous wall 100, which is convenient to operate and can also improve the safety of the connection between the horizontal support assembly 11 and the underground continuous wall 100.

[0045] S2: installing the surrounding purlin template 2;

[0046] The surrounding purlin template 2 is placed on the horizontal support assembly 11. The surrounding purlin template 2 is provided with a pull rod 21 extending in the horizontal direction, one end of the pull rod 21 is welded on the vertical main reinforcement 101, and the second end is sleeved with a limiting piece 22 abutting against the end face of the vertical support assembly 12 away from the underground continuous wall 100.

[0047] The above step, in the embodiment, the surrounding purlin template 2 is placed on the horizontal support assembly 11, and the pull rod 21 is provided on the surrounding purlin template 2, one end of the pull rod 21 is welded on the vertical main reinforcement 101, the other end is sleeved with the limiting piece 22, and the limiting piece 22 abuts against the outside of the vertical support assembly 12, forming a force system of the horizontal pull rod 21, preventing the deformation of the surrounding purlin template 2 and ensuring the stability of the surrounding purlin template 2.

[0048] Specifically, the surrounding purlin template 2 is made of a plurality of steel bars, and the specific size can be set as needed according to the construction demand, which is not limited here. The limiting piece 22 is a butterfly nut, which can be screwed by hand without the help of any tool, and the operation is very convenient.

[0049] Optionally, the support structure 1 further comprises horizontal pads 13 and vertical pads 14, the horizontal pads 13 are arranged between the horizontal support assembly 11 and the perimeter purlin template 2, for adjusting the vertical position of the perimeter purlin template 2, the vertical pads 14 are arranged between the vertical support assembly 12 and the perimeter purlin template 2, for adjusting the horizontal position of the perimeter purlin template 2, so that the perimeter purlin template 2 stably abuts on the underground continuous wall 100. The above arrangement can ensure the accuracy of the position of the perimeter purlin template 2, and reduce the construction deviation.

[0050] Further, the horizontal pads 13 comprise a plurality of horizontal pad bars 131 arranged in the horizontal direction, and the vertical pads 14 comprise a plurality of vertical pad bars 141 arranged in the vertical direction. The operator can flexibly select the pad bars with the required size according to the actual needs on site, so that the use is more flexible, and the accuracy of the position of the perimeter purlin template 2 can be ensured.

[0051] Further, the horizontal pad bars 131 and the vertical pad bars 141 are both wooden, i.e. the horizontal pad bars 131 and the vertical pad bars 141 are both wooden squares. The wooden square is extremely convenient to process, can be flexibly adjusted on site according to the actual situation, is easy to cut, and has a relatively light weight, so that the stable bearing of the support structure 1 on the perimeter purlin template 2 can be ensured. In addition, the cost of the wooden square is relatively low, and the wooden square is easy to obtain.

[0052] Optionally, the horizontal pad bars 131 and the vertical pad bars 141 are both fixed to the perimeter purlin template 2 by binding, so as to ensure the stability of the pad bars and prevent the pad bars from moving.

[0053] Optionally, a plurality of pull rods 21 are arranged in the vertical direction, so as to form a plurality of horizontal limiting and fixing positions for the perimeter purlin template 2, and prevent the perimeter purlin template 2 from deforming. For example, in the embodiment, two pull rods 21 are arranged in the vertical direction; in other embodiments, the number of the pull rods 21 can be arranged as required, which is not limited here.

[0054] S3: arranging the hanging bars 3;

[0055] The hanging bars 3 are connected between the perimeter purlin template 2 and the vertical main bars 101, and the hanging bars 3 are arranged at an angle with the vertical main bars 101.

[0056] In the embodiment, the first end of the hanging bar 3 is welded on the perimeter purlin template 2, and the second end is welded on the vertical main bar 101. The weight of the perimeter purlin template 2 is transmitted to the vertical main bars 101 of the underground continuous wall 100 through the hanging bar 3, and the horizontal pulling force provided by the pull rod 21 can stably fix the perimeter purlin template 2 on one side of the underground continuous wall 100.

[0057] Optionally, the angle α between the hanging rib 3 and the vertical main rib 101 ranges from 20° to 45°, that is, 20°≤α≤45°, and the angle β between the hanging rib 3 and the horizontal main rib 102 ranges from 135° to 160°, that is, 135°≤β≤160°. Figure 2 The angle α between the hanging rib 3 and the vertical main rib 101 ranges from 20° to 45°, that is, 20°≤α≤45°, and the angle β between the hanging rib 3 and the horizontal main rib 102 ranges from 135° to 160°, that is, 135°≤β≤160°. The setting of the angles can decompose the tension of the hanging rib 3 into two directions, in which the vertical component is responsible for pulling up the purlin formwork 2, and the horizontal component pulls the purlin formwork 2 towards the underground continuous wall 100, so that part of the load is transferred to the underground continuous wall 100. The above angle range can ensure that the horizontal component is sufficient to stably abut the purlin formwork 2 against the underground continuous wall 100, and avoid a huge tension caused by a too small angle.

[0058] For example, in the embodiment, the angle α is 27°, and the angle β is 153°.

[0059] Optionally, the hanging rib 3 is provided with multiple hanging ribs, so that even if one of the hanging ribs 3 fails, the remaining hanging ribs 3 can still jointly bear the load, greatly improving the safety of the purlin formwork 2; and the multiple hanging ribs 3 can disperse the weight of the purlin formwork 2 to a larger area of the underground continuous wall 100, optimize the load distribution, reduce local stress, and improve long-term reliability.

[0060] Optionally, the second end of the hanging rib 3 is connected with a reinforcing rib 4, the reinforcing rib 4 extends along the horizontal direction, and the end of the reinforcing rib 4 away from the hanging rib 3 is implanted into the underground continuous wall 100. The reinforcing rib 4 can balance the horizontal component, further improving the stability of the purlin formwork 2. At the same time, the reinforcing rib 4 is provided on the purlin formwork 2, effectively increasing the overall rigidity of the purlin formwork 2.

[0061] S4: pouring concrete purlin;

[0062] Pouring concrete into the purlin formwork 2 to form a concrete purlin.

[0063] Specifically, when the concrete purlin reaches a certain strength, the vertical support assembly 12, the horizontal support assembly 11, the vertical cushion layer 14 and the horizontal cushion layer 13 can be sequentially removed. The part of the pull rod 21 extending out of the concrete purlin can be cut off by a cutting device.

[0064] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, it is not necessary and impossible to enumerate all the embodiments. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A method for constructing concrete walers for foundation pits, characterized in that, Includes the following steps: S1: Install support structure (1); The vertical main reinforcement (101) of the underground continuous wall (100) corresponding to the waler position is chiseled out. The support structure (1) includes a horizontal support component (11) and a vertical support component (12). The vertical support component (12) is disposed at the first end of the horizontal support component (11), and the second end of the horizontal support component (11) is welded to the vertical main reinforcement (101). S2: Install waler template (2); The waler template (2) is placed on the horizontal support assembly (11); a tie rod (21) extending in the horizontal direction is passed through the waler template (2), one end of the tie rod (21) is welded to the vertical main reinforcement (101), and the other end is fitted with a limiting member (22), which abuts against the end face of the vertical support assembly (12) away from the underground continuous wall (100); S3: Install hanger rods (3); The hanging bar (3) is connected between the waler template (2) and the vertical main bar (101), and the hanging bar (3) and the vertical main bar (101) are set at an angle; S4: Pour concrete walers; Concrete is poured into the waler template (2).

2. The method for constructing a concrete waler for a foundation pit according to claim 1, characterized in that, The support structure (1) further includes a horizontal pad (13) and a vertical pad (14). The horizontal pad (13) is disposed between the horizontal support component (11) and the waler template (2), and the vertical pad (14) is disposed between the vertical support component (12) and the waler template (2).

3. The method for constructing concrete walers for foundation pits according to claim 2, characterized in that, The horizontal pad layer (13) includes a plurality of horizontal pads (131) spaced apart in the horizontal direction, and the vertical pad layer (14) includes a plurality of vertical pads (141) spaced apart in the vertical direction.

4. The method for constructing a concrete waler for a foundation pit according to claim 3, characterized in that, Both the horizontal pad (131) and the vertical pad (141) are made of wood.

5. The method for constructing a concrete waler for a foundation pit according to claim 4, characterized in that, Both the horizontal support rod (131) and the vertical support rod (141) are tied and fixed to the waler template (2).

6. The method for constructing a concrete waler for a foundation pit according to claim 1, characterized in that, The second end of the suspension bar (3) is connected to a reinforcing bar (4), which extends horizontally, and the end of the reinforcing bar (4) away from the suspension bar (3) is inserted into the underground continuous wall (100).

7. The method for constructing a concrete waler for a foundation pit according to claim 1, characterized in that, The range of the angle α between the suspension rod (3) and the vertical main bar (101) is: 20°≤α≤45°.

8. The method for constructing a concrete waler for a foundation pit according to any one of claims 1-7, characterized in that, The underground continuous wall (100) is planted with connecting bars (102), and the horizontal support component (11) is fixed to the end of the connecting bars (102).

9. The method for constructing a concrete waler for a foundation pit according to any one of claims 1-7, characterized in that, The tie rod (21) is provided in multiple vertically spaced positions.

10. The method for constructing a concrete waler for a foundation pit according to any one of claims 1-7, characterized in that, Multiple suspension rods (3) are provided.

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