An assembly type oblique combined support system for foundation pit support and a construction method thereof

Abstract

The application relates to the technical field of building construction, in particular to a fabricated oblique combined support system for foundation pit support and a construction method thereof, which comprises a support pile, a steel lattice column, a square pile body, an anchoring piece and a cushion block. The support pile is a composite structure of a PC method combined steel pipe pile and a cement mixing pile, and the inside of a foundation pit is transversely supported through the support pile. A pressing roof beam is arranged at the central top area of the support pile, an oblique pile bracket is arranged on one side of the pressing roof beam, shear plates are equidistantly arranged on the inside of the steel lattice column, high-strength bolts are adopted to fix the lowest shear plate along the steel lattice column, the rest of the shear plates are all fixed through welding, and connecting holes are arranged in the inside of the shear plates along the rectangular matrix direction. The square pile body is obliquely inserted into the foundation pit soil body through a static pressure method, and an annular positioning groove is arranged at the central position of the top end surface of the square pile body. The application effectively improves the uplift bearing capacity and overall stability of the oblique support.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and in particular to a prefabricated inclined combined support system for foundation pit support and its construction method. Background Technology

[0002] As a key technical measure to ensure the safety of underground engineering construction and the stability of the surrounding environment, the structural form, construction technology, and stress performance of foundation pit support directly affect the safety, cost, and construction period of the project. Among the many forms of foundation pit support, inclined support systems have been widely used in deep foundation pit engineering due to their advantages such as clear force transmission paths, small occupation of internal space in the foundation pit, and ease of earthwork excavation and main structure construction. Although traditional cast-in-place reinforced concrete inclined bracing has good integrity and high rigidity, its construction cycle is long, involves a lot of on-site wet work, materials are not recyclable, and the dismantling process generates a lot of noise and dust pollution, making it difficult to meet the current needs of green construction and rapid construction. To this end, prefabricated inclined support systems have emerged. By transporting prefabricated components such as steel lattice columns and precast concrete components from the factory to the site for rapid assembly and connection, it can realize an industrialized construction mode of "factory prefabrication and on-site assembly". It has significant advantages such as high construction efficiency, less on-site wet work, recyclable components, and environmental friendliness, and has become an important development direction in the field of foundation pit support technology.

[0003] Currently, there are already published patents related to prefabricated inclined support technology. For example, patent CN202322043803.2 discloses a "prefabricated inclined steel support device for foundation pit support in building engineering". It connects the two ends of the prefabricated steel support standard section to the crossbeam and the support respectively through concrete reaction supports set on the bottom plate of the foundation pit and prefabricated embedded steel supports embedded in the retaining structure, forming an inclined support system. However, the anchoring section at the bottom of the inclined support often adopts conventional single grouting anchoring method or simple grout bag extrusion structure. The anchor body and the pile body rely only on the adhesive friction between the grout and the hole wall or the single extrusion expansion body to provide pull-out resistance. There is a lack of a cooperative working mechanism for the step-by-step transfer of load between the anchoring section and the pile body. When the soil layer where the anchoring section is located is disturbed or groundwater is present, the bonding interface is prone to peeling, and the anchoring effect is significantly reduced.

[0004] Therefore, it is necessary to provide a prefabricated inclined combined support system for foundation pit support and its construction method to solve the above-mentioned technical problems. Summary of the Invention

[0005] To address the problems in the prior art, this invention provides a prefabricated inclined combined support system for foundation pit support and its construction method.

[0006] The technical solution adopted by the present invention to solve its technical problem is: a preparation device for biochar-based phosphorus-solubilizing bacteria, including support piles, steel lattice columns, square pile bodies, anchors and pads. The support piles are a composite structure of PC construction method combined steel pipe piles and cement mixing piles, and the support piles provide lateral support to the inner side of the foundation pit. A capping beam is set in the central top area of ​​the support piles, and an inclined pile bracket is set on one side of the capping beam.

[0007] Shear plates are equidistantly arranged on the inner side of the steel lattice column. The shear plate at the lowest position of the steel lattice column is fixed with high-strength bolts, and the shear plates at other positions are fixed by welding. Connection holes are opened inside the shear plate along the rectangular matrix direction.

[0008] The square pile body is inserted into the foundation pit soil at an angle by static pressure method. The top end face of the square pile body has a pre-set annular positioning groove at the center. The top end face of the square pile body has a threaded sleeve embedded in a square path. The square pile body has multiple longitudinally extending through holes along the axial direction. Anchors are inserted in the through holes.

[0009] The anchor has a bottom anchoring section and a top exposed section. The bottom anchoring section is used to be implanted into the cement-reinforced body to form an anchoring point. The top exposed section protrudes from the top of the square pile body and is inserted into the upper connecting hole to form a locking point.

[0010] The pad is installed in the gap between the steel lattice column and the square pile. The bottom of the pad is provided with a protruding ring that is inserted and fixed to the annular positioning groove. The inside of the pad is provided with an installation hole for the anchor to be inserted, and the contact point between the installation hole and the anchor is positioned by spot welding.

[0011] Preferably, the anchor includes a steel rod inserted into the through hole, and a conical frustum block is welded to the outer wall region of the bottom anchoring section of the steel rod.

[0012] Preferably, the bottom anchoring section of the steel rod is fitted with an outer sleeve, the top of the outer sleeve is fixedly connected to the bottom of the square pile body through a pre-embedded rod, an enlarged groove is opened in the inner part of the outer sleeve near the area of ​​the conical truncated block, and placement holes are symmetrically opened in the horizontal direction of the outer sleeve. A reinforcing plate is hinged in the placement hole, the opening of the placement hole is sealed by a sealing film, and a wedge block is welded to the inner side wall of the reinforcing plate.

[0013] Preferably, the top end of the steel rod has an external thread, and a positioning stud is installed in the area of ​​the external thread. An extension rod is provided at the center of the top end face of the positioning stud.

[0014] Preferably, the inner wall of the through hole is provided with an annular reinforcing groove, the steel rod is provided with a grouting groove at the center of the interior, and a leakage hole communicating with the annular reinforcing groove is provided along the horizontal direction of the grouting groove.

[0015] Preferably, a circular hole is provided laterally at the center of the annular reinforcing groove, a limit ring is provided on the inner wall of the circular hole near the opening, a convex block is inserted into the circular hole, and the end of the circular hole facing the annular reinforcing groove is sealed by a first diaphragm.

[0016] Preferably, an overflow hole is provided at the center of the interior of the convex block, and the end of the circular hole facing away from the annular reinforcing groove is sealed by a second diaphragm.

[0017] Furthermore, the present invention also provides a construction method for a prefabricated inclined composite support for foundation pit support, which specifically includes the following steps:

[0018] S1. Construction of support piles: Support piles are constructed along the edge of the foundation pit. The support piles are a composite structure of PC construction method combined steel pipe piles and cement mixing piles. In areas where vibration control is required, cement mixing piles are constructed first, and then steel pipe piles are implanted using non-resonance or static pressure methods to form a closed enclosure for the inner side of the foundation pit.

[0019] S2. Construction of reinforced body: According to the construction drawings, cement slurry is injected into the in-situ soil using an inclined mixing drill at the design angle and forced mixing is carried out to form a cylindrical cement reinforced body.

[0020] S3. Precast pile body implantation: The pad block and the anchor fastener inserted into the through hole of the square pile body are pre-assembled, so that the exposed top section of the anchor fastener passes through the mounting hole of the pad block, and the protruding ring at the bottom of the pad block is inserted into the annular positioning groove at the top of the square pile body and then locked and fixed by the threaded sleeve; before the cement solidification body initially sets, the pre-assembled pad block, anchor fastener and square pile body are pressed into the cement solidification body as a whole at an inclination, so that the bottom anchoring section of the anchor fastener extends into the cement solidification body, and the bottom of the anchor fastener and the bottom of the outer sleeve sleeved on its outside and fixed to the bottom of the square pile body maintain a preset axial distance;

[0021] S4. Diagonal support assembly: The steel lattice column with shear plates on the inner side is hoisted into place, so that the connecting holes on the shear plates are inserted and locked with the top exposed section of the anchor, and the bottom end of the steel lattice column is supported on the pad; then the upper end of the steel lattice column is connected to the capping beam at the top of the support pile to form a diagonal combined support force system.

[0022] S5. Composite Anchoring Formation: High-pressure grouting is performed into the grouting groove of the anchor. The grouting pressure drives the conical frustum block at the bottom of the anchor to squeeze the wedge block, forcing the reinforcing plate hinged in the outer sleeve placement hole to break through the sealing membrane and open outward, inserting into the cement reinforcement to form a barbed triangular structure. At the same time, the grout enters the annular reinforcement groove along the leakage hole and pushes the convex block to extend outward along the circular hole. After breaking through the first diaphragm and the second diaphragm in sequence, it sprays outward from the overflow hole, forming a continuously extending and branching concrete grout path with the surrounding soil.

[0023] Compared with related technologies, the prefabricated inclined combined support system for foundation pit support and its construction method provided by the present invention have the following beneficial effects:

[0024] (1) This invention provides a prefabricated inclined combined support system for foundation pit support and its construction method. The shear plates set at equal intervals in this invention are used to bear the horizontal shear force at the interface between the steel lattice column and the square pile. The lowest shear plate adopts a detachable design, which facilitates the recycling of the steel lattice column in the later stage. The rectangular matrix layout of the connecting holes ensures the precise alignment with multiple anchors, realizing multi-point and multi-directional load transfer. The bottom anchoring and top connection are realized simultaneously through a single anchor, constructing a direct and continuous force transmission path from the steel lattice column to the deep soil, avoiding the stress concentration and deformation incoordination problems caused by too many connection nodes in traditional construction.

[0025] (2) The present invention provides a prefabricated inclined combined support system for foundation pit support and its construction method. When subjected to compressive force, the reinforcing plate deflects at the hinge of the placement hole, pushing the sealing film into the uncured cement reinforcement to form a barbed triangular structure. The barbed triangular structure is inserted into the uncured cement reinforcement. After the cement reinforcement solidifies, a hard mechanical interlocking structure is formed. Its resistance to pull-out force is improved compared with traditional friction anchoring or single adhesive anchoring, effectively improving the pull-out bearing capacity and overall stability of the inclined support.

[0026] (3) The present invention provides a prefabricated inclined combined support system for foundation pit support and its construction method. During the high-pressure grouting process of the present invention, after the cavity inside the annular reinforcement groove is completely filled with concrete grout, grouting continues. The concrete grout will apply pressure to the first diaphragm, pushing the convex block to move laterally in the circular hole until the larger diameter position of the convex block contacts the limiting ring and stops moving. At this time, multiple convex blocks are exposed outside the circular hole and inserted into the cement reinforcement body, forming multiple anti-pull-out and anti-sinking points, which further improves the overall stability of the inclined combined support force system. The high-pressure grout flow will split the surrounding cement reinforcement body and soil along the path of least resistance, forming irregular grout veins, and continuously extending forward and branching concrete grout paths, further strengthening the stability of the square pile body inclined brace, and lacking a cooperative working mechanism for progressively transferring loads between the reinforcement plate, the conical truncated cone and the pile body. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure construction of the present invention;

[0028] Figure 2 This is a partial three-dimensional structure of the present invention. Figure 1 ;

[0029] Figure 3 This is a partial three-dimensional structure of the present invention. Figure 2 ;

[0030] Figure 4 This is a partial three-dimensional structure of the present invention. Figure 3 ;

[0031] Figure 5 This is a top view of the pad block of the present invention;

[0032] Figure 6 This is a cross-sectional view of a portion of the square pile body of the present invention;

[0033] Figure 7 For the present invention Figure 6 A magnified view of a portion of region A in the middle;

[0034] Figure 8 For the present invention Figure 6 A magnified view of a portion of region B in the middle;

[0035] Figure 9 For the present invention Figure 6 A magnified view of a portion of region C in the middle;

[0036] Figure 10 For the present invention Figure 6 A magnified view of a portion of region D in the middle;

[0037] Figure 11 This is a cross-sectional view of the positioning stud of the present invention;

[0038] Figure 12 This is a flowchart of the present invention.

[0039] The following are the labeling elements in the diagram: 1. Support pile, 2. Steel lattice column, 3. Square pile body, 4. Anchor, 5. Pad, 6. Outer sleeve, 7. Positioning stud, 11. Top beam, 12. Inclined pile bracket, 21. Shear plate, 22. Connecting hole, 31. Annular positioning groove, 32. Threaded sleeve, 33. Through hole, 34. Annular reinforcement groove, 35. Round hole, 36. Limiting ring, 37. Convex block, 371. Overflow hole, 372. Second diaphragm, 41. Steel rod, 42. Conical frustum, 43. Grouting groove, 44. Leakage hole, 51. Convex ring, 52. Mounting hole, 61. Embedded rod, 62. Expanded diameter groove, 63. Placement hole, 64. Reinforcing plate, 65. Through sealing membrane, 66. Wedge block, 71. Extension rod. Detailed Implementation

[0040] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0041] Furthermore, the terms used below are defined based on the functionality of this invention and may vary depending on the user's, operator's, or conventions. Therefore, these terms are defined based on the entire contents of this specification.

[0042] See Figure 1-12 The present invention discloses a prefabricated inclined combined support system for foundation pit support and its construction method, comprising support piles 1, steel lattice columns 2, square pile bodies 3, anchors 4 and pads 5. The support piles 1 are a composite structure of PC construction method combined steel pipe piles and cement mixing piles, and the support piles 1 provide lateral support to the inner side of the foundation pit. A capping beam 11 is provided in the central top area of ​​the support piles 1, and an inclined pile bracket 12 is provided on one side of the capping beam 11.

[0043] The inclined pile corbel 12 and the capping beam 11 can be cast as one piece, or they can be set up separately. The inclined pile corbel 12 is made of steel structure and is fixed to the outside of the capping beam 11 by high-strength bolts. Casting as one piece can ensure the connection strength, while the separate type is easy to disassemble and recycle, which improves the turnover rate of the components.

[0044] Shear plates 21 are provided at equal intervals on the inner side of the steel lattice column 2. The thickness of the shear plates 21 should not be less than 1.2cm. The shear plates 21 at the lowest position of the steel lattice column 2 are fixed with high-strength bolts to ensure that the shear plates 21 at this position can be removed.

[0045] The equidistant shear plates 21 are used to withstand the horizontal shear force at the interface between the steel lattice column 2 and the square pile body 3. The lowest shear plate 21 adopts a detachable design, which facilitates the recycling of the steel lattice column 2 in the later stage. The rectangular matrix layout of the connecting holes 22 ensures the precise alignment with multiple anchors 4, realizing multi-point and multi-directional load transfer.

[0046] All other shear plates 21 are fixed by welding, and the interior of the shear plate 21 is provided with connecting holes 22 along the rectangular matrix direction;

[0047] An annular positioning groove 31 is pre-set at the center of the top end face of the square pile body 3. A threaded sleeve 32 is embedded in the top end face of the square pile body 3 in a square path. Multiple longitudinally extending through holes 33 are opened in the square pile body 3 along the axial direction. An anchor 4 is inserted in the through holes 33.

[0048] The anchor 4 has a bottom anchoring section and a top exposed section. The bottom anchoring end is used to be implanted into the cement reinforcement 40 to form an anchoring point. The top exposed section protrudes from the top of the square pile body 3 and is inserted into the upper connecting hole 22 to form a locking point.

[0049] By using a single anchor 4 to simultaneously achieve bottom anchoring and top connection, a direct and continuous force transmission path is constructed from the steel lattice column 2 to the deep soil, avoiding stress concentration and deformation incoordination problems caused by too many connection nodes in traditional construction.

[0050] Before the cement solidification body 40 has initially set, the precast square pile body 3 is inclinedly pressed into the cement solidification body 40 using static pressure method or non-vibration implantation process, and the insertion angle should meet the construction requirements.

[0051] The pad 5 is installed in the gap between the steel lattice column 2 and the square pile body 3. The bottom of the pad 5 is provided with a protruding ring 51 that is inserted and fixed to the annular positioning groove 31. The inside of the pad 5 is provided with an installation hole 52 for the anchor 4 to be inserted, and the contact point between the installation hole 52 and the anchor 4 is positioned by spot welding.

[0052] The pad block 5 plays a role in bearing pressure and transmitting force between the square pile body 3 and the steel lattice column 2. The insertion structure of its convex ring 51 and the annular positioning groove 31 realizes the self-centering function, ensuring the verticality and installation accuracy of the steel lattice column 2.

[0053] The pad 5 and the anchor 4 can be regarded as a whole. Before the square pile body 3 is implanted, several anchors 4 should be inserted along the through hole 33 to form a whole with it (after the convex ring 51 enters the annular positioning groove 31, the high-strength bolt is tightened in the threaded sleeve 32). During the static pressure method of implantation, several anchors 4 are implanted together into the cement solidification body 40, that is, the bottom anchoring end of the anchor 4 is implanted into the cement solidification body 40 to form an anchoring point, thereby increasing the overall pull-out resistance and anti-sinking of the square pile body 3.

[0054] After the square pile body 3 is implanted, the steel lattice column 2 with shear plate 21 on the inner side is hoisted into place, so that the connecting hole 22 on the shear plate 21 is inserted and locked one by one with the top exposed section of the anchor 4. Then, the upper end of the steel lattice column 2 is connected to the inclined pile bracket 12 on one side of the top pressure beam 11 of the support pile 1 to form an inclined combined support force system.

[0055] Reference Figure 4 As shown, the anchor 4 includes a steel rod 41 that passes through the through hole 33. The surface of the steel rod 41 is sanded. A conical truncated block 42 is welded to the outer wall area of ​​the bottom anchoring section of the steel rod 41. The sanding treatment increases the contact area and adhesion between the steel rod 41 and the grout that is subsequently injected. The conical truncated block 42 can increase the contact area with the cement-reinforced solid 40.

[0056] In another embodiment, reference is made to Figures 1-8 As shown, the bottom anchoring section of the steel rod 41 is fitted with an outer sleeve 6. The top of the outer sleeve 6 is fixedly connected to the bottom of the square pile body 3 through the pre-embedded rod 61. When the anchor 4 is inserted into the through hole 33, the bottom of the anchor 4 and the bottom of the outer sleeve 6 are kept axially spaced.

[0057] The aforementioned axial spacing provides room for the anchor 4 to move axially relative to the outer sleeve 6;

[0058] An expansion groove 62 is provided inside the outer tube 6 near the area of ​​the conical frustum block 42. The outer tube 6 is provided with placement holes 63 symmetrically in the horizontal direction. A reinforcing plate 64 is hinged in the placement hole 63. The opening of the placement hole 63 is sealed by a sealing film 65. A wedge block 66 is welded to the inner wall of the reinforcing plate 64.

[0059] Due to the aforementioned axial spacing, when the square pile body 3 is implanted, the pad 5 is not connected to the top of the square pile body 3, and the reinforcing plates 64 at each position are retracted into the placement hole 63 under the protection of the sealing membrane 65 (this state can be referred to). Figure 6 (as shown in the L-end state), and during the implantation of the square pile body 3, the sand and gravel in the soil are blocked by the sealing membrane 65 to prevent them from entering the gap between the reinforcing plate 64 and the placement hole 63.

[0060] After the square pile 3 is implanted into the designated position, pressure is applied to the top of the pad 5 by pressurization, so that the convex ring 51 enters the annular positioning groove 31, and the position of the pad 5 is locked by high-strength bolts; while the pad 5 synchronously drives the steel rod 41 to move along the through hole 33 under pressure, that is, the bottom of the steel rod 41 moves in the outer sleeve 6, causing the conical frustum block 42 to contact the wedge block 66 and apply extrusion force to it;

[0061] Since the wedge block 66 and the reinforcing plate 64 are a single unit, under the action of compressive force, the reinforcing plate 64 deflects at the hinge point along the placement hole 63, pushing the sealing film 65 into the uncured cement solidified body 40, forming a barbed triangular structure (this state can be referred to). Figure 6 As shown in the R-end state, the barbed triangular structure is inserted into the uncured cement solidified body 40. After the cement solidified body 40 solidifies, a rigid mechanical interlocking structure is formed, which improves the resistance to pull-out force compared with traditional friction anchoring or single bond anchoring, effectively enhancing the pull-out bearing capacity and overall stability of the inclined support.

[0062] Furthermore, an annular reinforcing groove 34 is provided on the inner wall of the through hole 33, and a grouting groove 43 is provided in the center of the inside of the steel rod 41. A leakage hole 44 communicating with the annular reinforcing groove 34 is provided along the horizontal direction of the grouting groove 43.

[0063] After the square pile body 3 is implanted and the position of the pad block 5 is locked, the high-pressure grouting equipment is connected to the grouting groove 43, and concrete grout is injected into the grouting groove 43. The concrete grout enters the annular reinforcement groove 34 through the leakage hole 44, and the contact surface between the steel rod 41 and the square pile body 3 is reinforced for a second time by the concrete grout.

[0064] In another embodiment, reference is made to Figures 2-10 As shown, a circular hole 35 is laterally opened at the center of the annular reinforcing groove 34. A limit ring 36 is provided on the inner wall of the circular hole 35 near the opening. A convex block 37 is inserted into the circular hole 35. The end of the circular hole 35 facing the annular reinforcing groove 34 is sealed by a first diaphragm 38.

[0065] At the same time, the first diaphragm 38 limits the position of the convex block 37, so that the convex block 37 is always retracted into the round hole 35 during the implantation of the square pile body 3, thereby reducing the external pressure during the implantation of the square pile body 3.

[0066] During the high-pressure grouting process, after the cavity inside the annular reinforcement groove 34 is completely filled with concrete grout, grouting continues. The concrete grout will apply pressure to the first diaphragm 38, pushing the convex block 37 to move laterally within the circular hole 35 until the larger diameter position of the convex block 37 contacts the limiting ring 36 and stops moving. At this time, multiple convex blocks 37 are exposed outside the circular hole 35 and inserted into the cement reinforcement body 40, forming multiple pull-out and anti-sinking points, which further improves the overall stability of the inclined combined support force system.

[0067] Preferably, an overflow hole 371 is provided in the center of the interior of the convex block 37. The end of the round hole 35 facing away from the annular reinforcing groove 34 is sealed by the second diaphragm 372. When the larger diameter position of the convex block 37 contacts the limiting ring 36, the first diaphragm 38 on one side of the overflow hole 371 continues to be subjected to high pressure of concrete slurry. After reaching the deformation threshold of the first diaphragm 38, it ruptures, and the high-pressure concrete slurry will enter the overflow hole 371 and contact the second diaphragm 372.

[0068] The second diaphragm 372 continues to be subjected to high pressure from the concrete grout. Similarly, when the pressure on one side reaches the deformation threshold of the second diaphragm 372, it ruptures, and the high-pressure concrete grout will spray out from the overflow hole 371 (this state can be referred to). Figure 10 (As shown), it is mixed with cement-based solidified material 40;

[0069] Furthermore, the high-pressure grout flow will split the surrounding cement reinforcement 40 and soil along the path of least resistance, forming irregular grout veins, and continue to extend forward and branch concrete grout paths, further enhancing the stability of the square pile body 3 inclined bracing, and lacking a cooperative working mechanism for progressively transferring loads between the reinforcement plate 64, the conical truncated cone 42 and the pile body.

[0070] In another embodiment, reference is made to Figures 1-11 As shown, the top end of the steel rod 41 has an external thread, and a positioning stud 7 is installed in the external thread area. An extension rod 71 is provided in the center of the top end face of the positioning stud 7.

[0071] The extension rod 71 and the positioning stud 7 are integral parts, and are forged by high temperature melting. The extension rod 71 is inserted into the mounting hole 52 of the pad block 5 and moves together with the installation of the steel lattice column 2.

[0072] In this example, when the steel lattice column 2 is connected and fixed to the square pile body 3, the exposed section of the top of the steel rod 41 only passes through the bottom pad 5. Then, each extension rod 71 is pulled down and aligned with the external thread area of ​​the steel rod 41. The positioning stud 7 is manually turned to connect the extension rod 71 to the end of the steel rod 41. After the foundation pit construction is completed, the positioning stud 7 can be turned again to remove the extension rod 71. Therefore, the design length of the steel rod 41 can be appropriately reduced, and there is no need to cut it during disassembly, thus reducing construction costs.

[0073] Furthermore, the present invention also provides a method for producing nano-zero valent iron supported on biochar, which specifically includes the following steps:

[0074] S1. Construction of support piles: Support pile 1 is constructed along the edge of the foundation pit. Support pile 1 is a composite structure of PC construction method combined steel pipe pile and cement mixing pile. In areas where vibration control is required, cement mixing piles are constructed first, and then steel pipe piles are implanted using non-resonance or static pressure methods to form a closed enclosure for the inner side of the foundation pit.

[0075] S2. Construction of reinforced body: According to the construction drawings, GPS is used for layout, and cement slurry is sprayed into the soil in situ and forcibly mixed according to the design angle using an inclined mixing drill to form a cylindrical cement reinforced body 40.

[0076] S3. Precast pile body implantation: The pad block 5 and the anchor 4 inserted into the through hole 33 of the square pile body 3 are pre-assembled, so that the exposed top section of the anchor 4 passes through the mounting hole 52 of the pad block 5, and the protruding ring 51 at the bottom of the pad block 5 is inserted into the annular positioning groove 31 at the top of the square pile body 3 and then locked and fixed by the threaded sleeve 32; before the cement solidification body 40 is initially set, the pre-assembled pad block 5, anchor 4 and square pile body 3 are pressed into the cement solidification body 40 as a whole, so that the bottom anchoring section of the anchor 4 extends into the cement solidification body 40, and the bottom of the anchor 4 and the bottom of the outer sleeve 6 which is sleeved on its outside and fixed to the bottom of the square pile body 3 maintain a preset axial distance.

[0077] S4. Diagonal support assembly: The steel lattice column 2 with shear plates 21 on the inner side is hoisted into place, so that the connecting holes 22 on the shear plates 21 are correspondingly inserted and locked with the top exposed section of the anchor 4, and the bottom end of the steel lattice column 2 is supported on the pad block 5; then the upper end of the steel lattice column 2 is connected to the top pressure beam 11 of the support pile 1 to form a diagonal combined support force system.

[0078] S5. Composite Anchoring Formation: High-pressure grouting is performed into the grouting groove 43 of the anchor 4. The grouting pressure drives the conical frustum block 42 at the bottom of the anchor 4 to squeeze the wedge block 66, forcing the reinforcing plate 64, which is hinged in the placement hole 63 of the outer sleeve 6, to break through the sealing membrane 65 and open outward, inserting into the cement reinforcement 40 to form a barbed triangular structure. At the same time, the grout enters the annular reinforcement groove 34 along the leakage hole 44 and pushes the convex block 37 to extend outward along the circular hole 35. After breaking through the first diaphragm 38 and the second diaphragm 372 in sequence, it sprays outward from the overflow hole 371, forming a continuously extending and branching concrete grout path with the surrounding soil.

[0079] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A prefabricated inclined combined support system for foundation pit support, characterized in that, include: Support pile (1), the support pile (1) is a composite structure of PC construction method combined steel pipe pile and cement mixing pile, and the support pile (1) provides lateral support to the inside of the foundation pit. A capping beam (11) is provided in the central top area of ​​the support pile (1), and an inclined pile corbel (12) is provided on one side of the capping beam (11). A steel lattice column (2) is provided with shear plates (21) at equal intervals on the inner side of the steel lattice column (2). The shear plate (21) at the lowest position of the steel lattice column (2) is fixed with high-strength bolts, and the shear plates (21) at other positions are fixed by welding. The shear plate (21) has connecting holes (22) in the direction of the rectangular matrix. The square pile body (3) is inserted into the foundation pit soil at an inclination by static pressure method. The top end face of the square pile body (3) is pre-set with an annular positioning groove (31). The top end face of the square pile body (3) is embedded with a threaded sleeve (32) in a square path. Multiple longitudinally extending through holes (33) are opened in the square pile body (3) along the axial direction. Anchors (4) are inserted in the through holes (33). The anchor (4) has a bottom anchor section and a top exposed section. The bottom anchor section is used to be implanted into the cement reinforcement (40) to form an anchor point. The top exposed section protrudes from the top of the square pile body (3) and is inserted into the upper connecting hole (22) to form a locking point. The pad (5) is installed in the gap between the steel lattice column (2) and the square pile body (3). The bottom of the pad (5) is provided with a protruding ring (51) that is inserted and fixed to the annular positioning groove (31). The inside of the pad (5) is provided with an installation hole (52) for the anchor (4) to be inserted, and the contact point between the installation hole (52) and the anchor (4) is positioned by spot welding.

2. The prefabricated inclined combined support system for foundation pit support according to claim 1, characterized in that, The anchor (4) includes a steel rod (41) inserted into the through hole (33), and a conical frustum block (42) is welded to the outer wall area of ​​the bottom anchoring section of the steel rod (41).

3. The prefabricated inclined combined support system for foundation pit support according to claim 2, characterized in that, The bottom anchoring section of the steel rod (41) is fitted with an outer sleeve (6). The top of the outer sleeve (6) is fixedly connected to the bottom of the square pile body (3) through a pre-embedded rod (61). An expansion groove (62) is provided inside the outer sleeve (6) near the area of ​​the conical frustum block (42). The outer sleeve (6) is symmetrically provided with placement holes (63) in the horizontal direction. A reinforcing plate (64) is hinged in the placement hole (63). The opening of the placement hole (63) is sealed by a sealing film (65). A wedge block (66) is welded to the inner side wall of the reinforcing plate (64).

4. The prefabricated inclined combined support system for foundation pit support according to claim 3, characterized in that, The top end of the steel rod (41) is provided with an external thread, and a positioning stud (7) is installed in the external thread area. An extension rod (71) is provided in the center of the top end face of the positioning stud (7).

5. A prefabricated inclined combined support system for foundation pit support according to claim 4, characterized in that, The inner wall of the through hole (33) is provided with an annular reinforcing groove (34), and the steel rod (41) is provided with a grouting groove (43) in the center. A leakage hole (44) communicating with the annular reinforcing groove (34) is provided along the horizontal direction of the grouting groove (43).

6. A prefabricated inclined combined support system for foundation pit support according to claim 5, characterized in that, A circular hole (35) is provided horizontally at the center of the annular reinforcing groove (34). A limit ring (36) is provided on the inner wall of the circular hole (35) near the opening. A convex block (37) is inserted into the circular hole (35). The end of the circular hole (35) facing the annular reinforcing groove (34) is sealed by a first diaphragm (38).

7. A prefabricated inclined combined support system for foundation pit support according to claim 6, characterized in that, An overflow hole (371) is provided in the center of the interior of the convex block (37), and the end of the round hole (35) facing away from the annular reinforcing groove (34) is sealed by the second diaphragm (372).

8. A prefabricated inclined combined support system for foundation pit support according to claim 7, characterized in that, This includes a construction method for prefabricated inclined composite supports for foundation pit support, specifically comprising the following steps: S1. Construction of support piles: Support piles (1) are constructed along the edge of the foundation pit. The support piles (1) are a composite structure of PC construction method combined steel pipe piles and cement mixing piles. In the area where vibration needs to be controlled, cement mixing piles are constructed first, and then steel pipe piles are implanted in a non-resonance or static pressure manner to form a closed enclosure for the inside of the foundation pit. S2. Construction of reinforced body: According to the construction drawings, the inclined mixing drilling machine is used to spray cement slurry into the soil in situ and perform forced mixing according to the design angle to form a cylindrical cement reinforced body (40). S3, Precast pile body implantation: The pad (5) and the anchor (4) inserted into the through hole (33) of the square pile body (3) are pre-assembled so that the exposed top section of the anchor (4) passes through the mounting hole (52) of the pad (5), and the protruding ring (51) at the bottom of the pad (5) is inserted into the annular positioning groove (31) at the top of the square pile body (3) and then locked and fixed by the threaded sleeve (32); before the cement solidification body (40) is initially set, the pre-assembled pad (5), anchor (4) and square pile body (3) are pressed into the cement solidification body (40) as a whole, so that the bottom anchoring section of the anchor (4) extends into the cement solidification body (40), and the bottom of the anchor (4) and the bottom of the outer sleeve (6) which is sleeved on its outside and fixed to the bottom of the square pile body (3) maintain a preset axial distance; S4. Oblique support assembly: The steel lattice column (2) with shear plate (21) on the inner side is hoisted into place, so that the connecting hole (22) on the shear plate (21) is inserted and locked with the top exposed section of the anchor (4), and the bottom end of the steel lattice column (2) is supported on the pad (5); then the upper end of the steel lattice column (2) is connected to the top pressure beam (11) of the support pile (1) to form an oblique combined support force system. S5. Composite anchoring molding: High-pressure grouting is performed into the grouting groove (43) of the anchor (4). The grouting pressure drives the conical frustum block (42) at the bottom of the anchor (4) to squeeze the wedge block (66), forcing the reinforcing plate (64) hinged in the placement hole (63) of the outer sleeve (6) to break through the sealing membrane (65) and open outward, inserting into the cement reinforcement body (40) to form a barbed triangular structure. At the same time, the grout enters the annular reinforcement groove (34) along the leakage hole (44) and pushes the convex block (37) to extend outward along the circular hole (35), and then breaks through the first diaphragm (38) and the second diaphragm (372) in sequence before spraying outward from the overflow hole (371), forming a continuously extending and branching concrete grout path with the surrounding soil.

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