A double-row pile deformation reinforcement structure for deep foundation pit and construction method
By using a double-row pile deformation reinforced structure connected to the foundation base plate in a deep foundation pit, the deformation problem of the middle cantilever pile area is solved when there is a large span and sensitive buildings, and the uniform stress and construction efficiency of the foundation pit support structure are improved.
Patent Information
- Application Number
- CN202510074642.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-17
- Publication Date
- 2025-04-04
AI Technical Summary
During the excavation of deep foundation pits, the span of the vertical cantilever pile area in the middle is relatively large. When sensitive buildings exist on the outside of some foundation pits, support forms such as double rows of piles cannot meet the deformation requirements of sensitive buildings.
The deformation reinforcement structure of the deep foundation pit double-row pile is adopted. The double-row piles are connected to the foundation base plate through several evenly distributed steel pipe oblique braces assemblies, and the crown beam connection nodes and the cow leg connection nodes are combined to form a prefabricated steel structure component to uniformly transmit horizontal to soil pressure.
The uniform stress of the foundation pit support structure is achieved, the local deformation is avoided, and the deformation requirements of sensitive buildings is met. At the same time, the construction efficiency is improved, the construction period is saved, and resource waste is reduced.
Smart Images
Figure CN119754306A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of civil engineering and geotechnical engineering, and in particular relates to a deep foundation pit double-row pile deformation reinforcement structure and a construction method. Background Art
[0002] Double-row piles for deep foundation pits are a commonly used support structure used to provide stable support during deep foundation pit excavation to prevent the collapse of the foundation pit wall. The double-row pile structure consists of two rows of parallel piles and is usually used in projects with complex geological conditions and large foundation pit depths.
[0003] At present, for deep foundation pit projects with tight construction working surface, large area and inability to adopt horizontal full support of pile row combination, local horizontal support and vertical cantilever pile support in the middle are often adopted. However, when the span of the vertical cantilever pile area in the middle is large and there are sensitive structures outside this part of the foundation pit, the support form of double-row piles in the middle cantilever piles still cannot meet the deformation requirements of sensitive buildings. This requires that other auxiliary reinforcement measures must be taken to reinforce the double-row pile area. Summary of the invention
[0004] In view of this, the present invention aims to propose a double-row pile deformation reinforcement structure and construction method for a deep foundation pit, so as to solve the problem that when the span of the middle vertical cantilever pile area is large and there are sensitive structures outside some foundation pits, the middle cantilever piles using double-row piles and other support forms still cannot meet the deformation requirements of sensitive buildings.
[0005] To achieve the above object, the technical solution of the present invention is achieved as follows: The present invention provides a deformation reinforcement structure of double-row piles in a deep foundation pit, which is arranged when a double-row pile support project in a deep foundation pit adopts local horizontal support combined with middle cantilever piles and the span of the middle cantilever pile area is greater than 15m; the double-row piles in the reinforcement structure are connected to a foundation bottom plate through a number of evenly distributed steel pipe diagonal brace assemblies; in the steel pipe diagonal brace assemblies, a crown beam of the double-row piles is connected to the top of the steel pipe diagonal brace through a crown beam connection node, the steel pipe diagonal brace is inclined at a certain angle, and a bottom plate concrete corbel is connected to the bottom of the steel pipe diagonal brace through a corbel connection node, and the bottom plate concrete corbel is arranged on the foundation bottom plate.
[0006] Furthermore, the crown beam connection node includes steel bars and steel plates, the steel bars are connected to the steel plates by perforation plug welding, a number of the steel bars are evenly distributed on the steel plates, and the steel bars are integrally cast with double-row pile concrete.
[0007] Furthermore, the corbel connection node includes steel bars and steel plates, the steel bars are connected to the steel plates by plug welding, a number of the steel bars are evenly distributed on the steel plates, and the steel bars are integrally cast with the bottom plate concrete corbel concrete.
[0008] Furthermore, the bottom plate concrete corbel is integrally cast and connected to the foundation bottom plate through the steel bars inside the corbel.
[0009] The present invention also provides a construction method for a double-row pile deformation reinforcement structure of a deep foundation pit based on the above aspect, which comprises the following steps: step S1, excavating to the bottom of the double-row pile crown beam and casting it and the double-row pile crown beam concrete as a whole according to the position of the crown beam connection node; step S2, after the double-row pile crown beam reaches the strength requirement, performing slope construction of the pit counter-pressure soil according to the design requirements; step S3, excavating the foundation bottom plate to the vicinity of the bottom plate concrete corbel, and then performing overall concrete casting construction of the foundation bottom plate, the bottom plate concrete corbel and the corbel connection node; step S4, digging out the pit counter-pressure soil under the steel pipe diagonal brace; step S5, constructing the temporary uncast part of the foundation bottom plate, and then backfilling the gap fertilizer trough between the supporting piles and the foundation bottom plate according to the specific requirements of backfilling; step S6, after the remaining part of the foundation bottom plate reaches the design strength and the backfill part meets the requirements for removing the steel pipe diagonal brace, the steel pipe diagonal brace, the corbel connection node and the bottom plate concrete corbel are removed.
[0010] Further, in step S2, the height of the back pressure soil is not less than the excavation depth of the foundation pit. The width of the back pressure soil platform shall not be less than the excavation depth of the foundation pit. .
[0011] Furthermore, when there is a stable side slope in the soil slope in the foundation pit, the slope of the counter-pressure soil is consistent with the stable side slope in the soil slope in the foundation pit.
[0012] Furthermore, in step S3, the temporary uncast part of the foundation slab is treated with reserved steel bars according to the structural design requirements, and after the slab concrete corbel reaches the strength requirement, a steel pipe diagonal brace is erected, and the steel pipe diagonal brace is welded to the slab concrete corbel and the crown beam connection node respectively.
[0013] Furthermore, the inclination angle and tube length of the steel pipe diagonal brace are adjusted according to the position of the post-casting strip in the foundation slab; after the steel pipe diagonal brace is set, the position and angle of the slab concrete corbel are determined.
[0014] Compared with the prior art, the deep foundation pit double-row pile deformation reinforcement structure and construction method described in the present invention have the following advantages: In the deep foundation pit double-row pile deformation reinforcement structure described in the present invention, the horizontal earth pressure on the double-row piles is transmitted to the foundation bottom plate through steel pipe diagonal braces, which plays a similar role in controlling horizontal forces as the horizontal supports on both sides of the double-row piles, making the overall force of the foundation pit support structure more uniform and avoiding excessive local deformation of the foundation pit support structure.
[0015] The steel pipe diagonal braces, crown beam connection nodes and corbel connection nodes in the present invention are prefabricated steel structure components, which are easy to operate and have higher construction efficiency, saving construction period while ensuring safety; the steel pipe diagonal braces, crown beam connection nodes and corbel connection nodes can be recycled after processing after dismantling, reducing resource waste and lowering project costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.
[0017] In the attached picture: Figure 1 It is a schematic diagram of the deformation reinforcement integral support of double-row piles in a deep foundation pit according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a double-row pile deformation reinforcement structure for a deep foundation pit according to an embodiment of the present invention; Figure 3 It is a partial schematic diagram of the double-row pile deformation reinforcement structure for a deep foundation pit according to an embodiment of the present invention; Figure 4 A schematic diagram of a steel pipe diagonal brace and its upper connection nodes in a double-row pile deformation reinforcement structure for a deep foundation pit according to an embodiment of the present invention; Figure 5 It is a schematic diagram of the crown beam connection node in the deep foundation pit double-row pile deformation reinforcement structure according to an embodiment of the present invention; Figure 6 It is a schematic diagram of the process of the construction method of the double-row pile deformation reinforcement structure for a deep foundation pit according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the crown beam connection node in step S1 of the deep foundation pit double-row pile deformation reinforcement structure construction method according to an embodiment of the present invention; Figure 8 It is a schematic diagram of the construction of the back pressure soil in the pit in step S2 of the deep foundation pit double-row pile deformation reinforcement structure construction method according to an embodiment of the present invention; Fig. 9 It is a schematic diagram after the construction of step S3 in the method for constructing a double-row pile deformation reinforcement structure for a deep foundation pit according to an embodiment of the present invention; Fig.10 It is a schematic diagram after the construction of step S4 in the method for constructing a double-row pile deformation reinforcement structure for a deep foundation pit according to an embodiment of the present invention; Fig.11 It is a schematic diagram after the construction of step S5 in the method for constructing a double-row pile deformation reinforcement structure for a deep foundation pit according to an embodiment of the present invention; Fig.12 It is a schematic diagram of the process after the construction of step S6 in the method for constructing a double-row pile deformation reinforcement structure for a deep foundation pit according to an embodiment of the present invention.
[0018] Description of reference numerals: 1. Double row of piles; 2. Steel pipe diagonal brace; 3. Counter pressure soil; 4. Bottom plate concrete corbel; 5. Crown beam connection node; 51. Rebar; 52. Steel plate; 6. Corbel connection node; 7. Horizontal support; 8. Foundation bottom plate; 9. Temporary uncast part of the foundation bottom plate. DETAILED DESCRIPTION
[0019] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.
[0020] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.
[0021] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.
[0022] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.
[0023] See also Figure 1-Figure 5 As shown, Figure 1The left and right sides of the middle cantilever pile are horizontal supports 7. This embodiment provides a deep foundation pit double-row pile deformation reinforcement structure, which is provided when the deep foundation pit double-row pile support project adopts local horizontal support combined with middle cantilever piles and the span of the middle cantilever pile area is greater than 15m; the double-row piles 1 in the reinforcement structure are connected to the foundation bottom plate 8 through a number of evenly distributed steel pipe diagonal brace assemblies; in the steel pipe diagonal brace assembly, the crown beam of the double-row piles 1 is connected to the top of the steel pipe diagonal brace 2 through the crown beam connection node 5, the steel pipe diagonal brace 2 is inclined at a certain angle, the bottom plate concrete corbel 4 is connected to the bottom of the steel pipe diagonal brace 2 through the corbel connection node 6, and the bottom plate concrete corbel 4 is provided on the foundation bottom plate 8.
[0024] Specifically, in this embodiment, the crown beam connection node 5 includes a steel bar 51 and a steel plate 52. The steel bar 51 is connected to the steel plate 52 by perforation plug welding. A plurality of steel bars 51 are evenly distributed on the steel plate 52. The steel bars 51 and the double-row piles 1 are integrally cast with concrete.
[0025] Specifically, in this embodiment, the corbel connection node 6 includes steel bars 51 and steel plates 52. The steel bars 51 are connected to the steel plates 52 by perforation plug welding. Several steel bars 51 are evenly distributed on the steel plates 52. The steel bars 51 and the bottom plate concrete corbel 4 are integrally cast with concrete.
[0026] Specifically, in this embodiment, the bottom plate concrete corbel 4 and the foundation bottom plate 8 are integrally cast and connected with the foundation bottom plate 8 through the steel bars inside the corbel.
[0027] See also Figure 6-Figure 12 As shown, the present embodiment also provides a construction method for the double-row pile deformation reinforcement structure of a deep foundation pit based on the above aspect, which includes: step S1, excavating to the bottom of the double-row pile crown beam according to the position of the crown beam connection node 5, and integrally pouring it and the double-row pile crown beam concrete; step S2, after the double-row pile 1 crown beam reaches the strength requirement, the back pressure soil 3 in the pit is sloped according to the design requirements; step S3, excavating the foundation bottom plate 8 to the vicinity of the bottom plate concrete corbel 4, and then pouring the foundation bottom plate 8 and the bottom plate concrete The corbel 4 and the corbel connection node 6 are integrally poured with concrete; step S4, dig out the counter-pressure soil 3 in the pit under the steel pipe diagonal brace; step S5, construct the temporary uncast part 9 of the foundation bottom plate, and then backfill the gap fertilizer trough between the support pile and the foundation bottom plate 8 according to the specific backfill requirements; step S6, after the remaining part of the foundation bottom plate 8 reaches the design strength and the backfill part meets the requirements for removing the steel pipe diagonal brace 2, the steel pipe diagonal brace 2, the corbel connection node 6 and the bottom plate concrete corbel 4 are removed.
[0028] Specifically, in this embodiment, in step S2, the height of the back pressure soil 3 is not less than the excavation depth of the foundation pit. , the width of the counter pressure soil 3 platform shall not be less than the excavation depth of the foundation pit .
[0029] Specifically, in this embodiment, when there is a stable side slope on the soil slope in the foundation pit, the slope of the counter-pressure soil 3 is consistent with the stable side slope on the soil slope in the foundation pit.
[0030] Specifically, in this embodiment, in step S3, the temporary uncast part 9 of the foundation slab is reserved with steel bars according to the structural design requirements, and after the slab concrete corbel 4 reaches the strength requirement, the steel pipe diagonal brace 2 is erected, and the steel pipe diagonal brace 2 is welded and connected to the slab concrete corbel 4 and the crown beam connection node 5 respectively.
[0031] Specifically, in this embodiment, the inclination angle and tube length of the steel pipe brace 2 are adjusted according to the position of the post-cast strip in the foundation slab 8; after the steel pipe brace 2 is set, the position and angle of the slab concrete corbel 4 are determined.
[0032] Embodiment 1: In a certain project, the height of the counterpressure soil slope is 4m, the platform width is 3.5m, and the slope coefficient is 1.5.
[0033] According to the actual construction requirements, the reinforcement structure is refined into steel pipe diagonal brace with horizontal spacing of 8m, horizontal projection length of 11m, vertical projection length of 4.5m, and steel pipe diagonal brace 2 is spiral welded steel pipe with a diameter of 529mm. The angle between steel pipe diagonal brace 2 and the horizontal direction is . The steel bars 51 in the crown beam connection node 5 and the corbel connection node 6 are made of 12 third-grade threaded steel bars with a diameter of 25 mm, and are evenly perforated and plug-welded with the steel plate 52 at a spacing of 150 mm to 250 mm. The steel bars 51 are embedded in the crown beam and corbel connection node 6 of the double-row pile 1 by about 750 mm. During the construction process, it is recommended that the height of the back pressure soil should not be less than the excavation depth of the foundation pit under the premise of ensuring the stability of the soil slope. The width of the back pressure soil platform shall not be less than the excavation depth of the foundation pit. The slope of the counterpressure soil should be consistent with the stable side slope of the soil slope in the foundation pit.
[0034] In the double-row pile deformation reinforcement structure of deep foundation pit, the horizontal soil pressure on the double-row piles is transferred to the foundation bottom plate through the steel pipe diagonal brace, which plays a similar role in controlling the horizontal force as the horizontal supports on both sides of the double-row piles, making the overall force of the foundation pit support structure more uniform and avoiding the phenomenon of excessive local deformation of the foundation pit support structure. The steel pipe diagonal brace, crown beam connection node and corbel connection node are prefabricated steel structure components, which are simple to operate and have higher construction efficiency, saving construction time while ensuring safety; the steel pipe diagonal brace, crown beam connection node and corbel connection node can be recycled after being processed after dismantling, reducing resource waste and reducing project costs.
[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims
1. A double-row pile deformation reinforcement structure for a deep foundation pit, characterized in that: The invention is provided when a double-row pile support project for a deep foundation pit adopts local horizontal support combined with a middle cantilever pile and the span of the middle cantilever pile area is greater than 15 m; the double-row piles (1) in the reinforcement structure are connected to a foundation bottom plate (8) through a plurality of evenly distributed steel pipe diagonal brace assemblies; in the steel pipe diagonal brace assemblies, the crown beam of the double-row piles (1) is connected to the top of the steel pipe diagonal brace (2) through a crown beam connection node (5); the steel pipe diagonal brace (2) is inclined at a certain angle; the bottom plate concrete corbel (4) is connected to the bottom of the steel pipe diagonal brace (2) through a corbel connection node (6); and the bottom plate concrete corbel (4) is provided on the foundation bottom plate (8).
2. The deep foundation pit double-row pile deformation reinforcement structure according to claim 1 is characterized in that: The crown beam connection node (5) comprises a steel bar (51) and a steel plate (52); the steel bar (51) and the steel plate (52) are connected by perforation plug welding; a plurality of steel bars (51) are evenly distributed on the steel plate (52); and the steel bars (51) and the double-row piles (1) are integrally cast with concrete.
3. The deep foundation pit double-row pile deformation reinforcement structure according to claim 1 is characterized in that: The corbel connection node (6) comprises a steel bar (51) and a steel plate (52), wherein the steel bar (51) is connected to the steel plate (52) by plug welding, a plurality of steel bars (51) are evenly distributed on the steel plate (52), and the steel bars (51) and the bottom plate concrete corbel (4) are integrally cast with concrete.
4. The deep foundation pit double-row pile deformation reinforcement structure according to claim 1 is characterized in that: The bottom plate concrete corbel (4) and the foundation bottom plate (8) are integrally cast and connected with the foundation bottom plate (8) through the steel bars inside the corbel.
5. A construction method for a deep foundation pit double-row pile deformation reinforcement structure according to any one of claims 1 to 4, characterized in that: These include, Step S1, excavating to the bottom of the double-row pile crown beam and integrally pouring it with the double-row pile crown beam concrete according to the position of the crown beam connection node (5); Step S2, after the top beam of the double-row piles (1) reaches the strength requirement, the back pressure soil (3) in the pit is sloped according to the design requirements; Step S3, excavating the foundation slab (8) to the vicinity of the slab concrete corbel (4), and then integrally pouring concrete on the foundation slab (8), the slab concrete corbel (4) and the corbel connection node (6); Step S4, digging out the counter-pressure soil (3) in the pit under the steel pipe diagonal support; Step S5, constructing the temporary uncast part (9) of the foundation slab, and then backfilling the gap fertilizer trough between the support pile and the foundation slab (8) according to the specific backfilling requirements; Step S6, after the remaining part of the foundation slab (8) reaches the design strength and the backfilled part meets the requirements for removing the steel pipe brace (2), the steel pipe brace (2), the bracket connection node (6) and the bottom slab concrete bracket (4) are removed.
6. The construction method of the deep foundation pit double-row pile deformation reinforcement structure according to claim 5 is characterized in that: In step S2, the height of the back pressure soil (3) is not less than 2 / 3 of the excavation depth of the foundation pit, and the width of the platform of the back pressure soil (3) is not less than 1 / 2 of the excavation depth of the foundation pit.
7. The construction method of the deep foundation pit double-row pile deformation reinforcement structure according to claim 6 is characterized in that: When there is a stable side slope on the soil slope in the foundation pit, the slope of the counter pressure soil (3) is consistent with the stable side slope on the soil slope in the foundation pit.
8. The construction method of the deep foundation pit double-row pile deformation reinforcement structure according to claim 5 is characterized in that: In step S3, the temporary uncast part (9) of the foundation slab is treated with reserved steel bars according to the structural design requirements, and after the slab concrete corbel (4) reaches the strength requirement, a steel pipe diagonal brace (2) is erected. The steel pipe diagonal brace (2) is respectively welded to the slab concrete corbel (4) and the crown beam connection node (5).
9. The construction method of the deep foundation pit double-row pile deformation reinforcement structure according to claim 5 is characterized in that: The inclination angle and tube length of the steel pipe diagonal brace (2) are adjusted according to the position of the post-casting strip in the foundation bottom plate (8); after the steel pipe diagonal brace (2) is set, the position and angle of the bottom plate concrete corbel (4) are determined.