Deep foundation pit composite supporting structure and construction method

Abstract

The invention provides a deep foundation pit combined type supporting structure and a construction method, the deep foundation pit combined type supporting structure comprises a first row of piles, a second row of piles, a waterproof curtain, anchor rods and buttresses, the first row of piles are located on the inner side of the second row of piles, the first row of piles comprise a plurality of first supporting piles, and the second row of piles comprise a plurality of second supporting piles; the anchor rods are sequentially anchored into the two adjacent first supporting piles and the two adjacent second supporting piles in the radial direction of the first supporting piles. A blade is arranged at the position, located in the second supporting pile, of the anchor rod and rotationally connected with the anchor rod, a receding opening for the blade to rotate is formed in the anchor rod, and a rotating assembly for driving the blade to rotate is arranged in the anchor rod. The blade cuts the concrete to form a reinforcing space, the reinforcing space communicates with the receding opening, and a pouring opening is formed in one end of the anchor rod and communicates with the receding opening; the buttresses are connected with the bottoms of the first row of piles, and the ends, away from the second row of piles, of the anchor rods penetrate into the buttresses. According to the technical scheme, the overall stability of the supporting structure is improved while the effective construction space in the foundation pit is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of deep foundation pit support, and in particular to a deep foundation pit composite support structure and a construction method. Background Art

[0002] With the development of foundation construction projects, the requirements for the depth and strength of foundation pit construction are gradually increasing. In existing foundation pit support projects, pile row structures are often used to ensure the lateral strength and overall stability of foundation pit support. However, the vertical stability of the section at the bottom of the pile foundation with greater soil pressure is difficult to control, especially in deep foundation pits. The height of the pile foundation is high and the contact area with the surrounding soil is large. In the long-term support process, local deformation or overall pile foundation tilting is prone to occur. Although the support depth can be increased by combining large-area internal support, large-area internal support requires occupying part of the construction space, which prolongs the construction period.

[0003] Therefore, a deep foundation pit composite support structure is needed to ensure the effective construction space in the foundation pit while improving the overall stability of the support structure. Summary of the invention

[0004] An object of the present invention is to provide a deep foundation pit composite support structure and a construction method, which can improve the overall stability of the support structure while ensuring effective construction space in the foundation pit.

[0005] The deep foundation pit composite support structure and construction method provided in this application adopt the following technical solutions:

[0006] In a first aspect, the present invention provides a deep foundation pit composite support structure, comprising a first row of piles, a second row of piles, a water-stop curtain, an anchor rod, and a pier, wherein the first row of piles is located inside the second row of piles, the water-stop curtain is arranged close to the first row of piles, the first row of piles comprises a plurality of first support piles arranged around the foundation pit, the second row of piles comprises a plurality of second support piles arranged around the foundation pit, and the anchor rod is anchored into two adjacent first support piles and second support piles in sequence along the radial direction of the first support piles;

[0007] The anchor rod is provided with a plurality of blades at a position inside the second support pile, each of the blades is rotatably connected to the anchor rod, a clearance opening for the blades to rotate is provided on the anchor rod, and a rotating assembly for driving the blades to rotate is provided inside the anchor rod;

[0008] During the process of anchoring the anchor rod into the first supporting pile and the second supporting pile, the blade is located in the anchor rod. After the anchor rod is anchored into the first supporting pile and the second supporting pile, the blade is rotated to the outside of the anchor rod, with the blade edge facing outward. During the rotation process, the blade cuts the concrete to form a reinforcement space, which is connected to the clearance port. A pouring port is provided at one end of the anchor rod, which is arranged along the axial direction of the anchor rod and is connected to the clearance port.

[0009] The buttress is connected to the bottom of the first row of piles, the buttress is arranged along the circumference of the foundation pit, and one end of the anchor rod away from the second row of piles penetrates into the buttress.

[0010] By adopting the above technical scheme, through the composite support structure of the first row of piles, the second row of piles, the water-stop curtain, the anchor rod and the pier, when the pile row improves the lateral strength and stability of the foundation pit, the anchor rod cooperates with the pier to support the bottom of the first supporting pile and the second supporting pile, thereby reducing the inclination of the first supporting pile and the second supporting pile. After the anchor rod is anchored into the first supporting pile and the second supporting pile, the blade is rotated to the outside of the anchor rod to cut out a reinforced space. After concrete is poured into the anchor rod, the concrete flows from the anchor rod into the reinforced space, thereby improving the connection strength between the anchor rod and the second supporting pile. The pier is fixedly connected to the bottom of the first row of piles and the anchor rod is inserted into the pier to improve the connection strength between the anchor rod and the first supporting pile, thereby improving the overall stability of the support structure while ensuring the effective construction space in the foundation pit.

[0011] Preferably, the anchor rod is arranged obliquely, and the end of the anchor rod close to the second supporting pile is the lowest end of the anchor rod.

[0012] By adopting the above technical solution, the inclined anchor rods improve the strength of the connection between the anchor rods and the first supporting piles and the second supporting piles, further avoiding the possibility of tilting of the first row of piles and the second row of piles, and improving the support capacity.

[0013] Preferably, a side of the pier facing away from the first supporting pile forms a reinforcement slope, and the reinforcement slope is inclined from top to bottom in a direction away from the first supporting pile.

[0014] By adopting the above technical solution, the inclined surface is reinforced so that the cross section of the pier is trapezoidal, thereby improving the stability of the pier.

[0015] Preferably, the angle between the plane where the reinforcement slope is located and the straight line where the anchor rod is located is between 90° and 110°.

[0016] By adopting the above technical solution, a stable structure is formed between the pier and the anchor rod, thereby improving the stability and support of the anchor rod.

[0017] Preferably, a cap beam is provided on the top surface of the first row of piles and the second row of piles, and the cap beam covers the first row of piles and the second row of piles in the width direction.

[0018] By adopting the above technical solution, the crown beam connects the rows of the first supporting piles and the second supporting piles, thereby improving the force stability at the top ends of the first and second rows of piles, further avoiding the possibility of tilting of the first and second rows of piles, and improving the supporting capacity.

[0019] Preferably, a first steel mesh is provided in the crown beam, and a second steel mesh is provided in the pier.

[0020] By adopting the above technical solution, the first steel mesh improves the structural strength of the crown beam, and the second steel mesh improves the structural strength of the pier.

[0021] Preferably, the blades are arranged in multiple groups along the circumference of the anchor rod, and the length direction of the clearance opening is arranged along the axial direction of the anchor rod. The number of blades in each group is multiple, and the multiple blades in each group are arranged along the length direction of the clearance opening. The blades are semicircular, and a rotating shaft is provided at one radial end of the blade, and the rotating shaft is rotatably connected to the inner wall of the clearance opening. The thickness of the blade is smaller than the width of the clearance opening.

[0022] Preferably, the rotating assembly includes a driving rod, the driving rod is hollow, the outer peripheral wall of the driving rod is in contact with the inner peripheral wall of the anchor rod injection port, the driving rod is rotatably and slidably connected to the anchor rod, a trigger block is provided on the side of the blade close to the central axis of the anchor rod, the trigger block is located at the end of the blade radially provided with a rotating shaft, a slot for the trigger block to be clamped is provided on the peripheral side wall of the driving rod, and during the process of the anchor rod being anchored into the first supporting pile and the second supporting pile, the trigger block is clamped in the slot, so that the blade is located in the anchor rod;

[0023] The peripheral side wall of the driving rod is provided with a receiving groove for each group of blades to penetrate, the receiving groove penetrates the bottom wall of the driving rod, and the receiving groove is communicated with the clamping groove. When the driving rod is inserted into the injection port of the anchor rod, the trigger block enters the receiving groove, and then the driving rod is rotated to make the trigger block enter the clamping groove from the receiving groove, at which time the rotation of the blade is restricted. When the blade needs to be rotated, the driving rod is rotated back to make the blade rotate, and then the driving rod is pressed along the axial direction of the anchor rod toward the direction close to the second supporting pile. At this time, the inner wall of the receiving groove contacts the trigger block and pushes the blade to rotate to the outside of the yield port;

[0024] A flow opening is also provided on the peripheral side wall of the driving rod. When the driving rod moves along the axial direction of the anchor rod until the blade rotates to the outside of the clearance opening, the flow opening is communicated with the clearance opening.

[0025] By adopting the above technical solution, when the driving rod is inserted into the pouring port of the anchor rod, the trigger block enters the receiving groove, and then the driving rod is rotated to make the trigger block enter the clamping slot from the receiving groove. At this time, the rotation of the blade is restricted. When the blade needs to be rotated, the driving rod is rotated to allow the blade to rotate. Then the driving rod is pressed along the axial direction of the anchor rod toward the direction close to the second supporting pile. At this time, the inner wall of the receiving groove contacts the trigger block and pushes the blade to rotate to the outside of the clearance port, thereby realizing the cutting of the surrounding concrete. Finally, concrete is poured into the anchor rod, so that the concrete enters the reinforced space through the circulation port and the clearance port to improve the connection strength between the anchor rod and the second supporting pile.

[0026] Preferably, the driving rod is provided with a first fixing hole and a second fixing hole, the second fixing hole is farther away from the bottom end of the anchor rod than the first fixing hole, the first fixing hole and the second fixing hole both pass through the radial sides of the driving rod, the anchor rod is provided with a connecting hole, the connecting hole passes through the radial sides of the anchor rod, a fixing pin is arranged in the connecting hole, when the trigger block is located in the accommodating groove, the first fixing hole is connected with the connecting hole, and the fixing pin passes through the first fixing hole and the connecting hole at the same time, when the blade rotates to the outside of the yielding opening, the second fixing hole is connected with the connecting hole, and the fixing pin passes through the second fixing hole and the connecting hole at the same time.

[0027] By adopting the above technical solution, when the trigger block is located in the accommodating groove, the first fixing hole is connected with the connecting hole, and the fixing pin passes through the first fixing hole and the connecting hole at the same time, so as to ensure that the trigger block is located in the slot, thereby preventing the blade from rotating at will, and preventing the blade from being located outside the clearance opening during the process of the anchor rod being anchored into the first supporting pile and the second supporting pile, thereby preventing the blade from being damaged;

[0028] When the blade rotates to the outside of the yielding opening, the second fixing hole is communicated with the connecting hole, and the fixing pin passes through the second fixing hole and the connecting hole at the same time, so that the blade is kept in the reinforced space.

[0029] In a second aspect, the present invention provides a deep foundation pit construction method, comprising the following steps:

[0030] S1. Measure and lay out and determine the drilling positions of the first row of piles, the second row of piles and the water-stop curtain;

[0031] S2, placing the steel cage of the first supporting pile and the steel cage of the second supporting pile into the corresponding drilled holes and pouring concrete;

[0032] S3, pouring concrete into the hole of the water-stop curtain;

[0033] S4, supporting a first template above the first row of piles and the second row of piles, the first template surrounds the pile heads of the first row of piles and the second row of piles, a first steel mesh is arranged in the first template, the first steel mesh is tied to the pile heads of the first row of piles and the second row of piles, and then concrete is poured into the first template to form a cap beam;

[0034] S5, excavation of foundation pit;

[0035] S6, anchoring the anchor rod into the first supporting pile and the second supporting pile at an inclined angle, then rotating the blade to the outside of the clearance port, and then pouring concrete into the anchor rod through the pouring port, so that the concrete enters the reinforcement space through the flow port and the clearance port, thereby improving the connection strength between the anchor rod and the second supporting pile;

[0036] S7. Support a second formwork in the foundation pit, the second formwork surrounds the anchor rod, a second steel mesh is arranged in the second formwork, the second steel mesh is tied to the anchor rod, and then concrete is poured into the second formwork to form a pier.

[0037] Through the composite support structure of the first row of piles, the second row of piles, the water-stop curtain, anchor rods, piers and cap beams, when the piles are arranged to improve the lateral strength and stability of the foundation pit, the anchor rods cooperate with the piers to support the bottom of the first supporting piles and the second supporting piles, and the cap beams support the tops of the first supporting piles and the second supporting piles, thereby reducing the inclination of the first supporting piles and the second supporting piles, and improving the overall stability of the support structure while ensuring the effective construction space in the foundation pit.

[0038] In summary, this application includes the following beneficial technical effects:

[0039] According to the composite support structure for deep foundation pit of the embodiment of the present invention, through the composite support structure of the first row of piles, the second row of piles, the water-stop curtain and the anchor rods, piers and crown beams, when the piles are arranged to improve the lateral strength and stability of the foundation pit, the anchor rods cooperate with the piers to support the bottom of the first supporting piles and the second supporting piles, and the crown beams support the tops of the first supporting piles and the second supporting piles, thereby reducing the inclination of the first supporting piles and the second supporting piles. The construction space occupied by the anchor rods and the piers is not large but can provide an effective support effect. Therefore, the technical solution of the present application improves the overall stability of the support structure while ensuring the effective construction space in the foundation pit.

[0040] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0042] Figure 1 It is a structural schematic diagram of a deep foundation pit composite support structure, taking one side of the foundation pit as an example in an embodiment of the present application.

[0043] Figure 2 In the embodiment of the present application, one side of the foundation pit is used as an illustration, and after the foundation pit is hidden, it is used to display the structural schematic diagram of the overall support structure.

[0044] Figure 3 It is a schematic diagram of the cross-sectional structure of the overall support structure, using one side of the foundation pit as an example in the embodiment of the present application.

[0045] Figure 4 It is a schematic diagram of the structure of the anchor rod used to illustrate the embodiment of the present application.

[0046] Figure 5 It is a schematic diagram for showing the structure of the blade when the blade is located in the yielding opening in the embodiment of the present application.

[0047] Figure 6 It is a structural schematic diagram for showing the positional relationship between the blade and the driving rod when the driving rod pushes the blade to rotate to the state outside the yielding opening in the embodiment of the present application.

[0048] Reference numerals:

[0049] 1. First row of piles; 11. First supporting piles; 2. Second row of piles; 21. Second supporting piles; 3. Water-stop curtain; 4. Crown beam; 5. Anchor rod; 51. Make way port; 52. Injection port; 53. Connecting hole; 6. Pier; 61. Reinforced slope; 7. Blade; 71. Rotating shaft; 72. Trigger block; 8. Rotating assembly; 81. Drive rod; 811. Slot; 812. Accommodating slot; 813. Flow port; 814. First fixing hole; 815. Second fixing hole. DETAILED DESCRIPTION

[0050] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0051] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0052] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0053] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0054] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0055] In the specification and claims of the present invention, if the term "first" or "second" is involved, it may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means that the related objects are in an "or" relationship.

[0056] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which 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 to the present invention.

[0057] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" involved 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 an indirect connection 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 according to specific circumstances.

[0058] The composite supporting structure for a deep foundation pit according to an embodiment of the present invention is described in detail below with reference to the accompanying drawings.

[0059] First, refer to Figure 1-3 The deep foundation pit composite support structure includes a first row of piles 1, a second row of piles 2, a water-stop curtain 3, a crown beam 4, an anchor rod 5, and a pier 6. The first row of piles 1 is located on the inner side of the second row of piles 2, and the water-stop curtain 3 is arranged close to the first row of piles 1. The first row of piles 1 includes a plurality of first supporting piles 11 arranged around the foundation pit, and the second row of piles 2 includes a plurality of second supporting piles 21 arranged around the foundation pit.

[0060] The crown beam 4 is fixed to the pile heads of the first row of piles 1 and the second row of piles 2 at the same time. The crown beam 4 covers the first row of piles 1 and the second row of piles 2 in the width direction. The crown beam 4 improves the force stability of the first supporting piles 11 and the second supporting piles 21 and supports the tops of the first supporting piles 11 and the second supporting piles 21. A first steel mesh is arranged inside the crown beam 4 to improve the structural strength of the crown beam 4.

[0061] The anchor rod 5 is anchored into two adjacent first supporting piles 11 and two adjacent second supporting piles 21 in sequence along the radial direction of the first supporting piles 11 .

[0062] Reference Figure 4-6A plurality of blades 7 are arranged at the position of the anchor rod 5 located inside the second supporting pile 21, each blade 7 is rotatably connected to the anchor rod 5, a clearance opening 51 for the blades 7 to rotate is provided on the anchor rod 5, and a rotating assembly 8 for driving the blades 7 to rotate is arranged inside the anchor rod 5. During the process of the anchor rod 5 being anchored into the first supporting pile 11 and the second supporting pile 21, the blades 7 are located inside the anchor rod 5, and after the anchor rod 5 is anchored into the first supporting pile 11 and the second supporting pile 21, the blades 7 rotate to the outside of the anchor rod 5.

[0063] The blade 7 faces outwards, and the blade 7 cuts the concrete to form a reinforced space during rotation. The reinforced space is connected to the make way port 51 . A pouring port 52 is provided at one end of the anchor rod 5 , and the pouring port 52 is arranged along the axial direction of the anchor rod 5 , and the pouring port 52 is connected to the make way port 51 .

[0064] After the anchor rod 5 is anchored into the first supporting pile 11 and the second supporting pile 21, the blade 7 is rotated to the outside of the anchor rod 5 to cut out a reinforced space. After concrete is poured into the anchor rod 5, the concrete flows from the anchor rod 5 into the reinforced space to improve the connection strength between the anchor rod 5 and the second supporting pile 21.

[0065] The anchor rod 5 is arranged at an angle, and the end of the anchor rod 5 close to the second supporting pile 21 is the lowest end of the anchor rod 5. The inclined arrangement of the anchor rod 5 increases the strength of the connection between the anchor rod 5 and the first supporting pile 11 and the second supporting pile 21, further avoiding the possibility of tilting of the first row of piles 1 and the second row of piles 2, thereby improving the support capacity.

[0066] Reference Figure 1-3 The buttress 6 is connected to the bottom of the first row of piles 1 , and the buttress 6 is arranged along the circumference of the foundation pit. One end of the anchor rod 5 away from the second row of piles 2 penetrates into the buttress 6 .

[0067] A side of the buttress 6 facing away from the first supporting pile 11 forms a reinforcement slope 61, which is inclined from top to bottom in a direction away from the first supporting pile 11. The reinforcement slope 61 makes the cross section of the buttress 6 trapezoidal, thereby improving the stability of the buttress 6. A second steel mesh is arranged inside the buttress 6, thereby improving the structural strength of the buttress 6.

[0068] The angle between the plane where the reinforcement slope 61 is located and the straight line where the anchor rod 5 is located is between 90° and 110°. In this embodiment, 95° is used to form a stable structure between the pier 6 and the anchor rod 5, thereby improving the stability and support of the anchor rod 5.

[0069] Referring to the figure, six groups of blades 7 are arranged along the circumference of the anchor rod 5, and the length direction of the make way opening 51 is arranged along the axial direction of the anchor rod 5. The number of blades 7 in each group is four, and six make way openings 51 are arranged equidistantly along the circumference of the anchor rod 5. The make way openings 51 correspond to each group of blades 7 one by one, and the multiple blades 7 in each group are arranged along the length direction of the make way opening 51. The blades 7 are semicircular, and a rotating shaft 71 is provided at one radial end of the blades 7. The rotating shaft 71 is rotatably connected to the inner wall of the make way opening 51. The thickness of the blade 7 is less than the width of the make way opening 51, so that concrete can flow from the make way opening 51 to the reinforced space.

[0070] Reference Figure 5-6 The rotating assembly 8 includes a driving rod 81, which is hollow. The outer peripheral wall of the driving rod 81 fits with the inner peripheral wall of the injection port 52 of the anchor rod 5. The driving rod 81 is rotatably and slidably connected to the anchor rod 5. A trigger block 72 is provided on the side of the blade 7 close to the central axis of the anchor rod 5. The trigger block 72 is located at one end of the blade 7 where the rotating shaft 71 is radially provided. A clamping groove 811 for the trigger block 72 to be clamped is provided on the peripheral side wall of the driving rod 81. During the process of anchoring the anchor rod 5 into the first supporting pile 11 and the second supporting pile 21, the trigger block 72 is clamped in the clamping groove 811, so that the blade 7 is located in the anchor rod 5.

[0071] A receiving groove 812 for each group of blades 7 to penetrate is provided on the peripheral side wall of the driving rod 81, and the receiving groove 812 passes through the bottom wall of the driving rod 81, and the receiving groove 812 is connected to the clamping groove 811. When the driving rod 81 is inserted into the injection port 52 of the anchor rod 5, the trigger block 72 enters the receiving groove 812, and then the driving rod 81 is rotated to make the trigger block 72 enter the clamping groove 811 from the receiving groove 812, at which time the rotation of the blade 7 is restricted. When the blade 7 needs to be rotated, the driving rod 81 is rotated to allow the blade 7 to rotate, and then the driving rod 81 is pressed along the axial direction of the anchor rod 5 toward the direction close to the second supporting pile 21. At this time, the inner wall of the receiving groove 812 contacts the trigger block 72 and pushes the blade 7 to rotate to the outside of the clearance port 51.

[0072] A circulation port 813 is also provided on the peripheral side wall of the driving rod 81. When the driving rod 81 moves along the axial direction of the anchor rod 5 until the blade 7 rotates to the outside of the clearance port 51, the circulation port 813 is connected with the clearance port 51, and concrete is poured into the anchor rod 5, so that the concrete enters the reinforced space through the circulation port 813 and the clearance port 51, so as to improve the connection strength between the anchor rod 5 and the second supporting pile 21.

[0073] The driving rod 81 is provided with a first fixing hole 814 and a second fixing hole 815. The second fixing hole 815 is farther away from the bottom end of the anchor rod 5 than the first fixing hole 814. The first fixing hole 814 and the second fixing hole 815 both pass through the radial sides of the driving rod 81. The anchor rod 5 is provided with a connecting hole 53. The connecting hole 53 passes through the radial sides of the anchor rod 5. A fixing pin is arranged in the connecting hole 53.

[0074] When the trigger block 72 is located in the accommodating groove 812, the first fixing hole 814 is connected to the connecting hole 53, and the fixing pin passes through the first fixing hole 814 and the connecting hole 53 at the same time to ensure that the trigger block 72 is located in the slot 811, thereby preventing the blade 7 from rotating at will and preventing the blade 7 from being located outside the clearance opening 51 during the process of the anchor rod 5 being anchored into the first supporting pile 11 and the second supporting pile 21, thereby preventing the blade 7 from being damaged.

[0075] When the blade 7 rotates to the outside of the clearance opening 51, the second fixing hole 815 is communicated with the connecting hole 53, and the fixing pin passes through the second fixing hole 815 and the connecting hole 53 at the same time, so that the blade 7 remains in the reinforced space.

[0076] In the second aspect, the deep foundation pit construction method comprises the following steps:

[0077] S1, measuring and setting out and determining the drilling positions of the first row of piles 1, the second row of piles 2, and the water-stop curtain 3;

[0078] S2, placing the steel cage of the first supporting pile 11 and the steel cage of the second supporting pile 21 into the corresponding drilled holes and pouring concrete to form a double-layer lateral supporting structure;

[0079] S3, pouring concrete into the hole of the water-stop curtain 3 to form a water-stop protection structure;

[0080] S4, supporting a first template above the first row of piles 1 and the second row of piles 2, the first template surrounds the pile heads of the first row of piles 1 and the second row of piles 2, a first steel mesh is arranged in the first template, the first steel mesh is tied to the pile heads of the first row of piles 1 and the second row of piles 2, and then concrete is poured into the first template to form a cap beam 4, thereby improving the force stability of the top ends of the first row of piles 1 and the second row of piles 2;

[0081] S5, excavation of foundation pit;

[0082] S6, anchor the anchor rod 5 into the first supporting pile 11 and the second supporting pile 21 at an inclined angle, then rotate the blade 7 to the outside of the clearance opening 51, and then pour concrete into the anchor rod 5 through the pouring opening 52, so that the concrete enters the reinforcement space through the circulation opening 813 and the clearance opening 51, thereby improving the connection strength between the anchor rod 5 and the second supporting pile 21;

[0083] S7. Support a second formwork in the foundation pit. The second formwork surrounds the anchor rod 5. A second steel mesh is arranged in the second formwork. The second steel mesh is tied to the anchor rod 5. Then, concrete is poured into the second formwork to form a pier 6. The anchor rod 5 cooperates with the pier 6 to support the bottom of the first supporting pile 11 and the second supporting pile 21.

[0084] In summary, the first row of piles 1, the second row of piles 2, and the water-stop curtain 3 provide lateral support for the foundation pit, and the cap beam 4, the anchor rod 5, and the pier 6 provide support for the first row of piles 1 and the second row of piles 2, reducing the inclination of the first row of piles 1 and the second row of piles 2, thereby ensuring the effective construction space in the foundation pit while improving the overall stability of the support structure.

[0085] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A deep foundation pit composite support structure, characterized by: The invention comprises a first row of piles (1), a second row of piles (2), a water-stop curtain (3), an anchor rod (5), and a buttress (6); the first row of piles (1) is located inside the second row of piles (2); the water-stop curtain (3) is arranged close to the first row of piles (1); the first row of piles (1) comprises a plurality of first supporting piles (11) arranged around a foundation pit; the second row of piles (2) comprises a plurality of second supporting piles (21) arranged around a foundation pit; the anchor rod (5) is anchored into two adjacent first supporting piles (11) and two adjacent second supporting piles (21) in a radial direction of the first supporting piles (11); A plurality of blades (7) are arranged at a position of the anchor rod (5) located inside the second support pile (21), each of the blades (7) is rotatably connected to the anchor rod (5), a clearance opening (51) for the blades (7) to rotate is provided on the anchor rod (5), and a rotating assembly (8) for driving the blades (7) to rotate is arranged inside the anchor rod (5); During the process of anchoring the anchor rod (5) into the first supporting pile (11) and the second supporting pile (21), the blade (7) is located inside the anchor rod (5); after the anchor rod (5) is anchored into the first supporting pile (11) and the second supporting pile (21), the blade (7) rotates to the outside of the anchor rod (5), with the blade edge of the blade (7) facing outwards; during the rotation process, the blade (7) cuts the concrete to form a reinforced space, which is communicated with the clearance port (51); a pouring port (52) is provided at one end of the anchor rod (5); the pouring port (52) is arranged along the axial direction of the anchor rod (5), and the pouring port (52) is communicated with the clearance port (51); The buttress (6) is connected to the bottom of the first row of piles (1), the buttress (6) is arranged along the circumference of the foundation pit, and one end of the anchor rod (5) away from the second row of piles (2) penetrates into the buttress (6).

2. The deep foundation pit composite support structure according to claim 1 is characterized in that: The anchor rod (5) is arranged obliquely, and the end of the anchor rod (5) close to the second supporting pile (21) is the lowest end of the anchor rod (5).

3. The deep foundation pit composite support structure according to claim 1 is characterized in that: A side of the buttress (6) facing away from the first supporting pile (11) forms a reinforcement slope (61), and the reinforcement slope (61) is inclined from top to bottom in a direction away from the first supporting pile (11).

4. The deep foundation pit composite support structure according to claim 3 is characterized in that: The angle between the plane where the reinforcement slope (61) is located and the straight line where the anchor rod (5) is located is between 90° and 110°.

5. The deep foundation pit composite support structure according to claim 1 is characterized in that: A cap beam (4) is arranged on the top surface of the first row of piles (1) and the second row of piles (2); the cap beam (4) covers the first row of piles (1) and the second row of piles (2) in the width direction.

6. The deep foundation pit composite support structure according to claim 5 is characterized in that: A first steel mesh is arranged in the crown beam (4), and a second steel mesh is arranged in the buttress (6).

7. The deep foundation pit composite support structure according to claim 1 is characterized in that: The blades (7) are arranged in a plurality of groups along the circumference of the anchor rod (5); the length direction of the clearance opening (51) is arranged along the axial direction of the anchor rod (5); the number of blades (7) in each group is a plurality; the plurality of blades (7) in each group are arranged along the length direction of the clearance opening (51); the blades (7) are semicircular; a rotating shaft (71) is arranged at one radial end of the blades (7); the rotating shaft (71) is rotatably connected to the inner wall of the clearance opening (51); and the thickness of the blades (7) is smaller than the width of the clearance opening (51).

8. The deep foundation pit composite support structure according to claim 1 is characterized in that: The rotating assembly (8) comprises a driving rod (81), the driving rod (81) is hollow, the outer peripheral wall of the driving rod (81) is in contact with the inner peripheral wall of the anchor rod (5) injection port (52), the driving rod (81) is rotationally connected and slidably connected to the anchor rod (5), a trigger block (72) is arranged on the side of the blade (7) close to the central axis of the anchor rod (5), the trigger block (72) is located at the end of the blade (7) radially provided with the rotating shaft (71), a slot (811) for the trigger block (72) to be clamped is arranged on the peripheral side wall of the driving rod (81), and when the anchor rod (5) is anchored into the first supporting pile (11) and the second supporting pile (21), the trigger block (72) is clamped in the slot (811), so that the blade (7) is located in the anchor rod (5); The peripheral side wall of the driving rod (81) is provided with a receiving groove (812) for each set of blades (7) to penetrate, and the receiving groove (812) penetrates the bottom wall of the driving rod (81), and the receiving groove (812) is communicated with the clamping groove (811). When the driving rod (81) is inserted into the injection port (52) of the anchor rod (5), the trigger block (72) enters the receiving groove (812), and then the driving rod (81) is rotated to make the trigger block (72) move from the receiving groove to the locking groove (811). The receiving groove (812) enters the locking groove (811), and the blade (7) is restricted from rotating. When the blade (7) needs to be rotated, the driving rod (81) is rotated to allow the blade (7) to rotate, and then the driving rod (81) is pressed along the axial direction of the anchor rod (5) toward the direction close to the second supporting pile (21). At this time, the inner wall of the receiving groove (812) contacts the trigger block (72) and pushes the blade (7) to rotate to the outside of the clearance opening (51); A flow opening (813) is also provided on the peripheral side wall of the driving rod (81). When the driving rod (81) moves along the axial direction of the anchor rod (5) until the blade (7) rotates to the outside of the clearance opening (51), the flow opening (813) is communicated with the clearance opening (51).

9. The deep foundation pit composite support structure according to claim 8 is characterized in that: The driving rod (81) is provided with a first fixing hole (814) and a second fixing hole (815). The second fixing hole (815) is farther away from the bottom end of the anchor rod (5) than the first fixing hole (814). The first fixing hole (814) and the second fixing hole (815) both pass through the two radial sides of the driving rod (81). The anchor rod (5) is provided with a connecting hole (53). The connecting hole (53) passes through the two radial sides of the anchor rod (5). A fixing pin is arranged in the connecting hole (53). When the trigger block (72) is located in the accommodating groove (812), the first fixing hole (814) is connected to the connecting hole (53), and the fixing pin passes through the first fixing hole (814) and the connecting hole (53) at the same time. When the blade (7) rotates to the outside of the clearance opening (51), the second fixing hole (815) is connected to the connecting hole (53), and the fixing pin passes through the second fixing hole (815) and the connecting hole (53) at the same time.

10. A deep foundation pit construction method, using the deep foundation pit composite support structure according to any one of claims 1 to 9, comprising the following steps: S1, measuring and setting out and determining the drilling positions of the first row of piles (1), the second row of piles (2), and the water-stop curtain (3); S2, placing the steel cage of the first supporting pile (11) and the steel cage of the second supporting pile (21) into the corresponding drilled holes and pouring concrete; S3, pouring concrete into the hole of the water-stop curtain (3); S4, supporting a first template above the first row of piles (1) and the second row of piles (2), the first template surrounding the pile heads of the first row of piles (1) and the second row of piles (2), arranging a first steel mesh in the first template, the first steel mesh being tied to the pile heads of the first row of piles (1) and the second row of piles (2), and then pouring concrete into the first template to form a cap beam (4); S5, excavation of foundation pit; S6, anchoring the anchor rod (5) into the first supporting pile (11) and the second supporting pile (21) at an inclined angle, then rotating the blade (7) to the outside of the clearance opening (51), and then pouring concrete into the anchor rod (5) through the pouring opening (52), so that the concrete enters the reinforced space through the circulation opening (813) and the clearance opening (51), thereby improving the connection strength between the anchor rod (5) and the second supporting pile (21); S7. Support a second formwork in the foundation pit, the second formwork surrounds the anchor rod (5), a second steel mesh is arranged in the second formwork, the second steel mesh is tied to the anchor rod (5), and then concrete is poured into the second formwork to form a pier (6).

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