Bearing platform construction method under condition of limited space of foundation pit

By using double-sided steel formwork and fixing method of pulling steel ropes under the condition of limited space of the foundation pit, the problems of steel formwork template expansion, deformation and irregular dimensions in traditional bearing construction methods are solved, and the regularity of the bearing structure size and construction quality are improved.

CN119593425APending Publication Date: 2025-03-11ROAD & BRIDGE SOUTH CHINA ENG CO LTD +1
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Patent Information

Application Number
CN202411733879.0
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2024-11-29
Publication Date
2025-03-11

AI Technical Summary

Technical Problem

Under the condition of limited width of the foundation pit, traditional bearing construction methods are difficult to ensure the regularity of the bearing structure size and construction quality, especially the lack of operating space when installing and dismantling steel molds, resulting in large deviations in mold expansion, deformation, and size irregularity, flatness and protective layer.

Method used

The construction method of the bearing under the condition of limited space of the foundation pit includes installing double-sided steel formwork on the side of limited working space, and by embedding obliquely pulling pipes and setting up pulling steel ropes, the double-sided steel formwork and the single-sided steel formwork on the side with abundant space are tightened to fix the steel formwork to ensure the stability and construction quality of the bearing structure.

Benefits of technology

When the foundation pit space is limited, the regularity of the structure size and construction quality of the bearing can be effectively guaranteed, avoiding the problems of mold expansion, deformation and irregular dimensions of the steel mold formwork in traditional methods, and ensuring the flatness of the bearing and the quality of the protection layer.

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Abstract

The invention provides a bearing platform construction method under the condition of limited space of a foundation pit, which comprises the following steps of: inserting and driving a steel sheet pile support at the boundary of the foundation pit, then installing a double-sided steel template at the limited side of the working space after the foundation pit is excavated, then carrying out bearing platform steel bar construction, pre-burying an inclined opposite-pull pipe in the construction process, and firstly penetrating an opposite-pull steel rope into the inclined opposite-pull pipe, after the single-face steel formwork on the side with the sufficient working space is in place, one end of the opposite-pulling steel rope is fixed to the single-face steel formwork, the other end of the opposite-pulling steel rope is connected with a flange of the double-face steel formwork, then the opposite-pulling steel rope is fastened and pulled, and after the steel formwork is fixed, bearing platform pouring construction is conducted, then the single-face steel formwork is dismantled firstly, and after half of a foundation pit is backfilled, pouring construction is conducted. And then the double-face steel formwork is dismantled. A double-face steel formwork structure is adopted on the limited side of the operation space, the double-face steel formwork on the limited side of the operation space and the single-face steel formwork on the sufficient side of the operation space are tied and fixed through a method of oppositely pulling the steel wire ropes, in addition, by means of the mode of pre-burying the inclined oppositely-pulling pipes, on one hand, the oppositely-pulling steel wire ropes can be limited, and on the other hand, when the double-face steel formworks are dismantled, the double-face steel formworks can be dismantled; according to the construction method, under the condition that the space of a foundation pit is limited, the installed steel formworks can still be oppositely pulled, the steel formworks can be conveniently removed, and the size and quality indexes of the bearing platform are well guaranteed.
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Description

Technical Field

[0001] The present application relates to the technical field of foundation pile construction, and in particular to a foundation pile construction method under conditions of limited foundation pit space. Background Art

[0002] When there are existing roads or buildings on both sides, the support range of steel sheet piles in the foundation pit of the pedestal is limited. When there is no operating space reserved for the installation and removal of the steel formwork of the pedestal in the transverse direction of the bridge, the traditional method is to use earth formwork or wooden boards for padding. If earth formwork is used when the foundation pit of the pedestal is limited, it will cause irregular size of the pedestal. If simple wooden boards are used for padding, the space is limited and the back of the wooden boards cannot be passed through tie rods, resulting in problems such as mold expansion, deformation, irregular size, and large deviations in flatness and protective layer.

[0003] Therefore, we need to solve the problem of using steel formwork under the condition of limited foundation pit width to ensure the size of the pedestal structure and prevent construction from exceeding the square, and the problem of pedestal construction when there is no space for personnel to operate during installation and disassembly of the pedestal steel formwork. To solve the above problems, the present invention provides a new technical solution. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a foundation cap construction method under the condition of limited foundation pit space, and the adopted technical solution includes:

[0005] The foundation pile construction method under the condition of limited foundation pit space includes the following steps:

[0006] S1. Delineate the boundary of the foundation pit, measure the boundary dimensions of the foundation cap within the scope of the foundation pit and lay out the lines;

[0007] S2. Drive steel sheet piles along the foundation pit boundary, dig out the surface soil of the foundation pit, and install the foundation pit purlins;

[0008] S3, excavation of foundation pit, removal of pile heads and pouring of cushion layer;

[0009] S4. Determine the range of the working space according to the distance between the cap boundary and the steel sheet piles. The side where the cap boundary is at a wider distance from the steel sheet piles is determined as the side with ample working space, and the side where the cap boundary is at a narrower distance from the steel sheet piles is determined as the side with limited working space.

[0010] S5. Install double-sided steel formwork at the edge of the pedestal on the side with limited working space;

[0011] S6, Construction of the reinforcement of the cap, pre-embed oblique tension tubes in the reinforcement at the four chamfers of the cap;

[0012] S7. Arrange tensioning steel ropes in the oblique tensioning pipes;

[0013] S8. Install single-sided steel formwork at the edge of the pedestal on the side with ample working space;

[0014] S9, the adjacent single-sided steel formwork and double-sided steel formwork are obliquely pulled and tightened by tensioning steel ropes, one end of the tensioning steel rope connected to the double-sided steel formwork is fixed, and one end of the tensioning steel rope connected to the single-sided steel formwork is used as a tensioning and tightening end;

[0015] S10, pouring and curing of foundation concrete;

[0016] S11. Remove the single-sided steel formwork on the side with ample working space;

[0017] S12, backfill the foundation pit to half the depth of the foundation pit;

[0018] S13, dismantle the foundation pit purlins;

[0019] S14, pull out the double-sided steel formwork on the side with limited working space;

[0020] S15. Backfill the entire foundation pit and remove the steel sheet piles.

[0021] According to the foundation foundation construction method under limited foundation pit space conditions of an embodiment of the present invention, the double-sided steel formwork includes a back panel and an inner panel, and internal stiffening keels and stiffening ribs arranged between the back panel and the inner panel.

[0022] According to the method for foundation foundation construction under limited foundation pit space conditions of an embodiment of the present invention, the single-sided steel formwork includes a panel and a back keel and stiffening ribs arranged on the back side of the panel.

[0023] According to the foundation foundation space limited condition foundation ...

[0024] According to the foundation foundation construction method under limited pit space conditions of an embodiment of the present invention, the width of the working space on the side with limited working space is 0.2 m, and the width of the working space on the side with ample working space is 1.5 m.

[0025] According to the foundation foundation construction method under limited foundation pit space conditions of an embodiment of the present invention, the oblique tension pipes are PVC pipes.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention adopts a double-sided steel formwork structure on the side with limited working space, and fastens the double-sided steel formwork on the side with limited working space and the single-sided steel formwork on the side with ample space by pulling steel wire ropes. In addition, the method of pre-buried oblique pulling pipes can limit the pulling steel ropes on the one hand, and on the other hand, when the double-sided steel formwork is removed, the pulling steel ropes can also be pulled out from the oblique pulling pipes. The construction method provided by the present invention can pull the installed steel formworks when the foundation pit space is limited, and it is convenient to remove the steel formworks, thereby better ensuring the size and quality indicators of the base. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0029] Figure 1 The construction plane in the embodiment of the present invention is Figure 1 ;

[0030] Figure 2 The construction plane in the embodiment of the present invention is Figure 2 ;

[0031] Figure 3 The construction section in the embodiment of the present invention is Figure 1 ;

[0032] Figure 4 The construction section in the embodiment of the present invention is Figure 2 .

[0033] Description of main component symbols:

[0034] 10. Foundation pit; 20. Capping platform; 30. Cushion layer; 40. Double-sided steel formwork; 50. Single-sided steel formwork; 60. Oblique tension pipe; 70. Tension steel rope; 80. Foundation pit purlin. DETAILED DESCRIPTION

[0035] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0036] In the description of the present invention, the meaning of "above", "below", "exceed", etc. is not inclusive of the number itself, and the meaning of "above", "below", "within", etc. is inclusive of the number itself. If there is a description of "first" or "second", it is only used to distinguish the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0037] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0038] In the present invention, unless otherwise clearly defined, the words "set", "install", "connect" and the like should be understood in a broad sense, for example, they can be directly connected or indirectly connected through an intermediate medium; they can be fixedly connected or detachably connected or integrally formed; they can be mechanically connected; they can be the internal connection of two elements or the interaction relationship between two elements. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0039] Example

[0040] The present invention is used for the construction method of the cap under the condition of limited foundation pit space. If the foundation pit steel sheet pile is only 20 to 30 centimeters away from the design edge line of the cap 20, according to the traditional steel template installation and removal method, the steel template installation space is insufficient and the tie rod installation and removal construction cannot be carried out. The present invention adopts a special steel template structure and its tie-in method to ensure that the steel template construction can still be used when the edge line of the cap 20 is only 20 to 30 centimeters away from the foundation pit steel sheet pile support (the conventional width is 1.2 to 1.5m to ensure that personnel enter to install and remove the steel template) to ensure the structural parameters and quality indicators of the cap 20 construction, such as Figures 1 to 4 As shown, the specific steps are as follows:

[0041] S1, delineate the boundary of the foundation pit 10, measure the boundary size of the cap 20 within the scope of the foundation pit 10 and lay out the line;

[0042] S2, inserting steel sheet piles along the boundary of the foundation pit 10 for support, digging out the surface soil of the foundation pit 10, and installing the foundation pit surrounding purlin 80;

[0043] S3, excavation of foundation pit 10, removal of pile heads and pouring of cushion layer 30;

[0044] S4. Determine the range of the working space according to the distance between the edge of the cap 20 and the steel sheet piles. The side where the distance between the edge of the cap 20 and the steel sheet piles is wider is determined as the side with ample working space, and the side where the distance between the edge of the cap 20 and the steel sheet piles is narrower is determined as the side with limited working space. In the embodiment, the side with limited working space is in the transverse direction of the bridge, and its working space width is 20-30 cm. The side with ample working space is in the longitudinal direction of the bridge, and its working space width is 1.5 m.

[0045] S5. Install a double-sided steel formwork 40 at the boundary of the pedestal 20 on the side where the working space is limited, wherein the double-sided steel formwork 40 includes a back panel and an inner panel, and an internal stiffening keel and stiffening ribs arranged between the back panel and the inner panel;

[0046] S6, construction of reinforcement of the cap 20, pre-embedding oblique tension pipes 60 in the reinforcement at the four chamfers of the cap 20, the oblique tension pipes 60 being PVC pipes;

[0047] S7, arranging the tensioning steel rope 70 in the oblique tensioning tube 60;

[0048] S8. Install a single-sided steel formwork 50 at the boundary of the pedestal 20 on the side with sufficient working space. The single-sided steel formwork 50 includes a panel and a back keel and stiffening ribs arranged on the back side of the panel;

[0049] S9, the adjacent single-sided steel formwork 50 and double-sided steel formwork 40 are obliquely pulled and tightened by the tensioning steel rope 70, one end of the tensioning steel rope 70 connected to the double-sided steel formwork 40 is fixed, and one end of the tensioning steel rope 70 connected to the single-sided steel formwork 50 is used as a tensioning and tightening end;

[0050] S10, pouring and curing of concrete for foundation 20;

[0051] S11, dismantle the single-sided steel formwork 50 on the side with ample working space;

[0052] S12, backfilling the foundation pit 10 to half the depth of the foundation pit 10;

[0053] S13, dismantle the foundation pit purlin 80;

[0054] S14, pulling out the double-sided steel formwork 40 on the side where the working space is restricted;

[0055] S15. Backfill all foundation pit 10 and remove the steel sheet piles.

[0056] The present invention is used for a foundation pile construction method under the condition of limited space of a foundation pit 10. It first inserts steel sheet piles at the boundary of the foundation pit 10 for support. Then, after the foundation pit 10 is excavated, a double-sided steel formwork 40 is installed at the boundary of the foundation pile 20 on the side with limited working space. The double-sided steel formwork 40 is installed in place before the reinforcement of the foundation pile 20 is installed. After it is in place, the steel components and the steel sheet piles are temporarily spot welded and fixed. Then, the reinforcement of the foundation pile 20 is constructed. During the construction process, an oblique tensioning pipe 60 is pre-buried. At this time, the tensioning steel rope 70 is first inserted into the oblique tensioning pipe 60. After the single-sided steel formwork 50 on the side with sufficient working space is in place, one end of the tensioning steel rope 70 is fixed to the single-sided steel formwork 50, and the other end is flange-connected to the double-sided steel formwork 40. Then, a jack is used to tighten and tie the tensioning steel rope 70 at the tensioning and tightening end. At this point, the steel formwork is fixed. In the present invention, the bridge-oriented operation Conventional single-sided steel formwork 50 is used on the side with ample space, and double-sided steel formwork 40 is used on the side with limited working space in the transverse direction of the bridge. The traditional construction method uses a tie rod to pull the two steel formworks against each other. The tie rod used is generally a fine-rolled threaded steel or round steel. In the present invention, a tensioning steel rope 70 is used for tensioning, and the single-sided steel formwork 50 on the side with ample space and the double-sided steel formwork 40 on the side with limited space are pulled against each other; after the steel formwork is fixed, the foundation 20 is cast and constructed, and then the single-sided steel formwork 50 is removed first. After half of the foundation pit 10 is backfilled, the double-sided steel formwork 40 is removed. Since one end of the tensioning steel rope 70 is tensioned and fixed to the double-sided steel formwork 40, when the double-sided steel formwork 40 is pulled out using a plug-in machine, the tensioning steel rope 70 will be pulled out along the pre-buried oblique tensioning pipe 60, and will be pulled out of the foundation pit 10 along with the double-sided steel formwork 40. At this point, the steel formwork is completely removed.

[0057] The present invention adopts a double-sided steel formwork 40 structure on the side with limited working space, and uses the method of pulling steel wire ropes to tie and fix the double-sided steel formwork 40 on the side with limited working space and the single-sided steel formwork 50 on the side with ample space. In addition, the method of pre-embedded oblique pulling tubes 60 can limit the pulling steel ropes 70 on the one hand, and on the other hand, when the double-sided steel formwork 40 is removed, the pulling steel ropes 70 can also be pulled out from the oblique pulling tubes 60. The construction method provided by the present invention can pull the installed steel formworks when the space of the foundation pit 10 is limited, and it is convenient to remove the steel formworks, thereby better ensuring the size and quality indicators of the base 20.

[0058] Of course, the present invention is not limited to the above-mentioned embodiments, and those skilled in the art may make equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications and substitutions are all included in the scope defined by the claims of this application.

Claims

1. A method for foundation pile construction under limited foundation pit space, characterized in that: The following steps are included: S1, delineating the boundary of the foundation pit (10), measuring the boundary dimensions of the foundation bearing platform (20) within the scope of the foundation pit (10) and laying out the boundaries; S2, inserting steel sheet piles for support along the boundary of the foundation pit (10), excavating the surface soil of the foundation pit (10), and installing the foundation pit surrounding purlin (80); S3, excavation of foundation pit (10), removal of pile heads and pouring of cushion layer (30); S4, determining the range of the working space according to the distance between the edge of the cap (20) and the steel sheet piles, the side where the distance between the edge of the cap (20) and the steel sheet piles is wider is determined as the side with ample working space, and the side where the distance between the edge of the cap (20) and the steel sheet piles is narrower is determined as the side with limited working space; S5, installing a double-sided steel formwork (40) at the boundary of the support platform (20) on the side where the working space is restricted; S6, constructing the steel bars of the cap (20), pre-embedding oblique tension pipes (60) in the steel bars at the four chamfered corners of the cap (20); S7, arranging a tensioning steel rope (70) in the oblique tensioning tube (60); S8, installing a single-sided steel formwork (50) at the edge of the support platform (20) on the side with sufficient working space; S9, the adjacent single-sided steel formwork (50) and double-sided steel formwork (40) are pulled obliquely and tightened by using a tensioning steel rope (70), one end of the tensioning steel rope (70) connected to the double-sided steel formwork (40) is fixed, and one end of the tensioning steel rope (70) connected to the single-sided steel formwork (50) is used as a tensioning and tightening end; S10, pouring and curing concrete of the cap (20); S11, dismantling the single-sided steel formwork (50) on the side with ample working space; S12, backfilling the foundation pit (10) to half the depth of the foundation pit (10); S13, dismantling the foundation pit purlin (80); S14, pulling out the double-sided steel formwork (40) on the side where the working space is restricted; S15. The foundation pit (10) is completely backfilled and the steel sheet piles are removed.

2. The method for foundation pile construction under limited foundation pit space according to claim 1, characterized in that: The double-sided steel formwork (40) comprises a back panel and an inner panel, and an internal stiffening keel and stiffening ribs arranged between the back panel and the inner panel.

3. The method for foundation pile construction under limited foundation pit space according to claim 1, characterized in that: The single-sided steel formwork (50) comprises a panel and a back keel and stiffening ribs arranged on the back side of the panel.

4. The method for foundation pile construction under limited foundation pit space according to claim 1, characterized in that: The side with limited working space is the transverse direction of the bridge, and the side with ample working space is the longitudinal direction of the bridge.

5. The method for foundation pile construction under limited foundation pit space according to claim 1, characterized in that: The width of the working space on the side with limited working space is 0.2 m, and the width of the working space on the side with ample working space is 1.5 m.

6. The method for foundation pile construction under limited foundation pit space according to claim 1, characterized in that: The obliquely pulled tube (60) is a PVC tube.