A composite steel pipe inclined support structure for deep foundation pits and its construction method

Abstract

This invention relates to the field of foundation pit support technology, specifically proposing a combined steel pipe inclined support structure and construction method for deep foundation pits; it includes multiple support pipes, connecting plates, plug-in shafts, drive ends, and movable ends; flanges are provided at both ends of the support pipes; multiple support pipes are connected in series via connecting plates; an internal support frame is detachably installed inside the support pipe, and the plug-in shaft is rotatably installed on the corresponding internal support frame; the drive end is detachably fixed at the flange end of the left support pipe and is sleeved with the plug-in shaft inside the left support pipe; the movable end is axially sliding and adjustablely installed at the flange end of the right support pipe; the inclined support structure for deep foundation pits provided by this invention, through its quick disassembly and assembly design and internal reinforced support design, improves construction efficiency and ensures construction safety.

Description

Technical Field

[0001] This invention relates to the field of foundation pit support technology, and specifically proposes a combined steel pipe inclined support structure and construction method for deep foundation pits. Background Technology

[0002] In urban environments, when constructing deep foundation pits, the limited construction space due to the surrounding buildings often necessitates the use of a retaining structure with inclined supports. This involves rigidly fixing the inclined supports at both ends between the building foundation and the capping beam or lintel of the retaining piles during the deep foundation pit construction. This counteracts the soil and water pressure on the outer soil layer of the retaining piles, restricts the inward deformation and overturning of the support structure, prevents the collapse of the surrounding soil, controls the settlement of the surrounding soil layers, ensures construction safety within the foundation pit, and protects the stability of surrounding buildings, pipelines, and other structures.

[0003] In the current technology, in order to improve the flexibility and efficiency of construction, the inclined support structure is generally assembled by connecting and connecting multiple specifications of support steel pipes. The support steel pipes are connected by flanges and fixed by bolts, so that multiple independent support steel pipes form a whole support steel pipe group.

[0004] The multiple supporting steel pipes are connected by bolts, and about ten bolts are needed to fix each pair of supporting steel pipes. In addition, a large number of supporting steel pipe groups are needed in the foundation pit for diagonal support. The large number of bolts makes it difficult to connect and disassemble the supporting steel pipes, which affects the construction efficiency.

[0005] During deep foundation pit construction, the operations of excavators, rotary drilling rigs, pile drivers, vibratory compactors, and earthmoving vehicles place the foundation pit in a continuous or intermittent vibration disturbance environment. This directly affects the overall rigidity and bending resistance of the supporting steel pipe assembly. Under the continuous influence of vibration disturbance, bolts are prone to loosening, thus affecting the rigid transmission of the supporting force, reducing the reliability and stability of the support, and also reducing construction safety. At the same time, the increased length of the supporting steel pipe after multiple sections are joined together results in a significant decrease in effective bending resistance, making it more prone to bending deformation under vibration, causing a decrease in the stability of the inclined support. In addition, although the supporting steel pipe is designed to be recyclable, once the supporting steel pipe is bent and deformed, it is not convenient for subsequent reuse, and may even lead to the scrapping of the supporting steel pipe. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a deep foundation pit combined steel pipe inclined support structure and construction method, which solves the problems mentioned in the background art.

[0007] A deep foundation pit composite steel pipe inclined support structure includes multiple support pipes, a connecting plate, a plug-in shaft, a drive end, and a movable end. Flanges are provided at both ends of the support pipes. Multiple support pipes are connected in series via the connecting plate. The connecting plate includes a disc body with both ends embedded in the flange ports of two support pipes. Multiple snap-fit ​​components are circumferentially distributed on the sidewall of the disc body, each sliding radially along the disc body. A drive shaft, coaxially rotatably cooperating with the center of the disc body, is installed through the disc body. The drive shaft drives the multiple snap-fit ​​components to slide synchronously. The plug-in shaft is keyed to both ends of the drive shaft and is placed inside the support pipe. An internal support frame is detachably installed inside the support pipe, and the plug-in shaft is rotatably mounted on the corresponding internal support frame. The drive end is detachably fixed at the flange end of the left support pipe and sleeved with the plug-in shaft inside the left support pipe. The movable end is axially slidably and adjustablely installed at the flange end of the right support pipe.

[0008] The drive end is used to drive multiple plug-in shafts and multiple drive shafts to rotate synchronously, and drive multiple snap-fit ​​components on each docking plate to snap into the corresponding flange holes on the flanges of the two end support tubes, and the flanges of the two support tubes are tightly attached to both ends of the plate body.

[0009] Preferably, the snap-fit ​​assembly includes a sliding part that slides radially along the disc body. Snap-fit ​​blocks are fixedly attached to the sliding part at both axial ends of the disc body. A snap-fit ​​seam is formed between the snap-fit ​​blocks and the end face of the disc body. The flange holes on the support tube, corresponding to the multiple snap-fit ​​assemblies, are oblong holes, through which the snap-fit ​​blocks can pass. When the drive shaft drives the snap-fit ​​assembly, causing the sliding part to slide closer to the center of the disc body, the oblong holes snap into the snap-fit ​​seam.

[0010] Preferably, the drive end includes an inner cylinder embedded in the support tube and fixed to the flange, a lead screw coaxially arranged and threadedly mounted inside the inner cylinder, and a connecting cylinder that is key-fitted to the plug shaft at one end of the lead screw.

[0011] Preferably, the movable end includes a movable cylinder that is slidably fitted into the support tube, and a sliding sleeve is coaxially disposed and rotatably installed inside the movable cylinder, the sliding sleeve being sleeved on the insertion shaft.

[0012] Preferably, the side wall of the disc body is provided with a plurality of radial grooves corresponding to a plurality of snap-fit ​​assemblies, and each radial groove is provided with a stepped hole extending radially; the snap-fit ​​assembly also includes a guide rod fixed to the sliding part, the guide rod is slidably installed in the stepped hole, and a return spring is sleeved on the guide rod, with the two ends of the return spring fixed to the sliding part and the step of the stepped hole, respectively.

[0013] Preferably, the disc body has a central hole at its center; the drive shaft includes a connecting post passing through the central hole, with drive discs fixed at both ends of the connecting post, and the two drive discs are rotatably mounted at both ends of the disc body; the stepped hole communicates with the central hole, and the guide rod passes through the stepped hole and extends into the central hole; the buckling assembly also includes a movable pin fixed to one end of the guide rod extending into the central hole; multiple guide holes corresponding to multiple buckling assemblies are provided on the mutually facing end faces of the two drive discs, and the two ends of the movable pin move along the corresponding guide holes on the two drive discs respectively.

[0014] Preferably, the drive shaft further includes two bushings, which are symmetrically arranged and fixed on opposite end faces of the two drive discs; the plug shaft is plugged into the bushings.

[0015] Preferably, the movable end further includes a plurality of screws fixed on the movable cylinder and slidingly engaged with the flange of the support pipe, and the movable end can be fixed on the flange of the support pipe by means of nuts cooperating with the screws.

[0016] Preferably, the two end faces of the disc body are fixed with bearing bushes that cooperate with the drive disc on the same side. The drive disc is located inside the bearing bushes, and multiple balls that roll and cooperate with the bearing bushes are movably embedded in the side wall of the drive disc along the circumferential direction.

[0017] In addition, the present invention also provides a construction method for a deep foundation pit combined steel pipe inclined support structure, including the following steps: S1, determining the position, angle and length of each inclined support according to the scope of the deep foundation pit.

[0018] S2. Precast the upper support pier and the corresponding lower support pier according to each determined inclined support position.

[0019] S3. Select the appropriate support pipe for each diagonal support position and pre-assemble it into a diagonal support structure.

[0020] S4. Hoist the inclined support structure to the corresponding inclined support position, which is located between the lower support pier and the upper support pier.

[0021] S5. By adjusting the flexible end, the two ends of the inclined support structure are supported on the lower and upper supports respectively and then fixed.

[0022] S6. Carry out the replacement support plate construction. After the strength is reached, hoist and dismantle the diagonal support structure.

[0023] The above technical solution has the following advantages or beneficial effects: This invention provides a deep foundation pit combined steel pipe inclined support structure, which adopts a flexible modular design for multi-component docking assembly. The support pipes are connected by docking discs instead of traditional bolt connections. The axial series connection of the plug shafts and the drive end drive method can realize the integrated and rapid series connection of multiple support pipes through the docking discs, solving the problem of troublesome and inefficient docking caused by the mass bolt connection between support pipes. The radial synchronous locking and axial clamping of the docking discs ensure the stability of the docking of two support pipes, avoiding the problem of easy loosening of bolt connections during subsequent construction. In addition, the multiple docking discs and multiple plug shafts connected alternately along the axial direction, together with the drive end and the movable end at both ends, not only realize the axial series connection of multiple support pipes, but also form a support skeleton that forms internal support for multiple support pipes. This makes up for the defect of reduced bending resistance caused by the lengthening of multiple support pipes due to docking, improves the overall bending strength of the inclined support structure, further enhances the stability and reliability of the inclined support, reduces the probability of support pipes being scrapped due to deformation, and improves the recyclability of support pipes. In summary, the inclined support structure for deep foundation pits provided by this invention, through its quick assembly and disassembly design and internal reinforced support design, improves construction efficiency and ensures construction safety. Attached Figure Description

[0024] The invention, its features, shape, and advantages will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. Like reference numerals denote like parts throughout the drawings, which are not intentionally drawn to scale; the focus is on illustrating the spirit of the invention.

[0025] Figure 1 This is a three-dimensional structural diagram of a combined steel pipe inclined support structure for deep foundation pits.

[0026] Figure 2 This is a three-dimensional sectional view of a deep foundation pit composite steel pipe inclined support structure.

[0027] Figure 3 yes Figure 2 A magnified view of a portion of point A in the middle.

[0028] Figure 4 yes Figure 2 A magnified view of a section at point B.

[0029] Figure 5 yes Figure 2 A magnified view of a section at point C.

[0030] Figure 6 This is a three-dimensional structural diagram of the support tube.

[0031] Figure 7 It is a three-dimensional structural diagram of the docking plate.

[0032] Figure 8 This is a three-dimensional sectional view of the disc.

[0033] Figure 9 It is a three-dimensional sectional view of the snap-fit ​​assembly and the drive shaft assembly.

[0034] Figure 10 This is a 3D structural diagram of the driver end.

[0035] Figure 11 This is a three-dimensional structural diagram of the active end.

[0036] Figure 12 This is a construction status diagram of the inclined support structure.

[0037] Figure 13 This is a flowchart of a construction method for a deep foundation pit combined steel pipe inclined support structure.

[0038] In the diagram: 1. Support tube; 2. Connecting plate; 21. Plate body; 211. Center hole; 212. Radial groove; 213. Stepped hole; 214. Positioning ring; 22. Snap-fit ​​assembly; 221. Sliding part; 222. Snap-fit ​​block; 223. Snap-fit ​​seam; 224. Guide rod; 225. Return spring; 226. Moving pin; 23. Drive shaft; 231. Drive plate; 232. Guide hole; 233. Ball bearing; 2 34. Connecting column; 235. Bushing; 24. Bearing shell; 3. Insert shaft; 4. Inner support frame; 5. Drive end; 51. Inner sleeve; 52. Screw hole seat; 53. Lead screw; 54. Connecting sleeve; 6. Flexible end; 61. Flexible sleeve; 62. Bearing seat; 63. Sliding sleeve; 64. Screw rod; 71. Lower support pier; 72. Upper support pier; 73. Support pile; 74. Crown beam; 75. Support plate band; 76. Building foundation. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] like Figure 1 and Figure 2As shown, a deep foundation pit composite steel pipe inclined support structure includes multiple support pipes 1 with flanges welded to both ends, docking plates 2 for connecting multiple support pipes 1 in series, a drive end 5 detachably fixed at the flange end of the left support pipe 1, and a movable end 6 axially slidably and adjustablely installed at the flange end of the right support pipe 1; the support pipes 1 are cylindrical steel pipes, and multiple support pipes 1 are assembled and connected to form a composite steel pipe inclined support structure, which also includes multiple insertion shafts 3 that connect the drive end 5, multiple docking plates 2, and movable end 6 in series along the axial direction.

[0042] Note: The combined steel pipe diagonal support structure will be referred to as the diagonal support structure below for ease of description.

[0043] like Figure 1 and Figure 12 As shown, in deep foundation pit construction, it is often used to construct building foundations 76. Taking the construction of raft foundation type building foundations 76 as an example, according to the entire deep foundation pit range, the location distribution points of each inclined support structure are determined in advance, and the support angle and support length of the inclined support structure are determined. First, the upper support pier 72 is constructed. The single row of support piles 73 are connected laterally through the capping beam 74 or the waist beam. In this embodiment, the laterally connected structure is the capping beam 74. According to the distribution position of the inclined support structure, the upper support pier 72 is poured at the corresponding distribution points on the capping beam 74. After the upper support pier 72 has been cured to the qualified strength, the soil in the inclined support area is excavated in layers to the top elevation of the retained soil platform, and the soil outside the inclined support range is excavated in layers to the raft foundation. After the base layer is completed, the raft base is cast and formed, and the lower support 71 corresponding to each upper support 72 is cast on the raft base. The two ends of the inclined support structure are respectively supported and fixed to the lower support 71 and the corresponding upper support 72. The mating surfaces of the lower support 71 and the upper support 72 in contact with the top support of the inclined support structure must be parallel, and the sum of the angle of the mating surface relative to the horizontal plane and the support angle of the inclined support structure is 90°. The lower support 71 and the upper support 72 are both cast with pre-embedded steel reinforcement anchoring structures that are fixedly connected to the inclined support structure. In this embodiment, the two ends of the inclined support structure are bolted to the lower support 71 and the upper support 72. Therefore, the steel reinforcement anchoring structure corresponds to high-strength bolts.

[0044] like Figure 2 , Figure 3 , Figure 6 , Figure 7 and Figure 8As shown, in order to facilitate flexible assembly, the support pipe 1 is provided with various length specifications, such as 2m, 3m or 4m. Depending on the length of the inclined support, various specifications of support pipe 1 can be selected for combination and connection. In order to facilitate subsequent hoisting, the support pipe 1 can be pre-welded with lifting rings or pre-set with lifting ring mounting holes. The docking plate 2 is used to connect and connect between the flanges of two support pipes 1. The docking plate 2 includes a disc-shaped plate body 21, which is integrally formed. In this embodiment, the diameter of the plate body 21 is slightly smaller than the flange diameter of the support pipe 1. In order to coordinate the coaxial positioning of the plate body 21 with the flange ports of the two support pipes 1, a positioning ring 214 is coaxially provided on both end faces of the plate body 21. The outer diameter of the positioning ring 214 is slightly smaller than the inner diameter of the support pipe 1. The plate body 21 can be inserted into the pipes of the two support pipes 1 through the two positioning rings 214. A central hole 211 is provided in the center of the plate body 21. Eight radial grooves 212 are evenly distributed in the circumference on the side wall of the plate body 21. A stepped hole 213 extending radially is provided in each radial groove 212. The stepped hole 213 communicates with the central hole 211. A notch is provided on both end faces of the plate body 21 corresponding to each radial groove 212.

[0045] like Figure 3 , Figure 7 , Figure 8 and Figure 9 As shown, a snap-fit ​​assembly 22 is installed in each radial groove 212 on the disc body 21. Eight oblong holes are provided on the flange of the support tube 1 to correspond to the eight snap-fit ​​assemblies 22. The snap-fit ​​assembly 22 includes a sliding part 221 that is slidably installed in the radial groove 212. Snap-fit ​​blocks 222 are arranged opposite each other on the axial ends of the disc body 21 on the sliding part 221. Two snap-fit ​​blocks 222 extend from corresponding notches on the two end faces of the disc body 21. The snap-fit ​​blocks 222 are L-shaped and include an axial section parallel to the axial direction of the disc body 21 and a radial section. The axial section is a round rod structure with a radius slightly smaller than the radius of the semicircular end of the oblong hole on the flange of the support tube 1, while the radial section... For the waist-shaped block structure adapted to the waist-shaped hole, the radial section can pass through the waist-shaped hole; the snap block 222 forms a snap slot 223 through the cooperation between the radial section and the end face of the disc 21, the snap slot 223 faces the center of the disc 21 and the width is slightly larger than the flange thickness of the support tube 1; a guide rod 224 is welded on the sliding part 221, the guide rod 224 is slidably installed in the stepped hole 213 and extends through into the central hole 211, a return spring 225 is sleeved on the guide rod 224, the two ends of the return spring 225 are respectively welded to the sliding part 221 and the step of the stepped hole 213; a moving pin 226 is welded to the end of the guide rod 224 extending into the central hole 211, the moving pin 226 is arranged parallel to the axial direction of the disc 21.

[0046] like Figure 3 , Figure 7 , Figure 8and Figure 9 As shown, a drive shaft 23 is installed through the center of the disc body 21 and rotates coaxially with it. The drive shaft 23 includes a connecting post 234 passing through the central hole 211. The two ends of the connecting post 234 are arranged opposite to each other and fixed with the drive disc 231 by bolts. On both sides of the disc body 21, there are bearing bushes 24 that cooperate with the drive disc 231 on the same side by bolts. The bearing bushes 24 are located inside the positioning ring 214 and the bearing bushes 24 are a half-spliced ​​structure. The drive disc 231 is located inside the bearing bushes 24. The inner side wall of the bearing bushes 24 is provided with an annular ball bearing 233 groove. Multiple balls 233 that roll and cooperate with the ball bearing 233 groove are evenly distributed and embedded in the side wall of the drive disc 231 along the circumference to reduce the rotational resistance of the drive disc 231. Eight guide holes 232, which correspond to eight snap-fit ​​components 22, are provided on the mutually facing end faces of the two drive disks 231. The guide holes 232 are extension holes and are blind holes. The two ends of the moving pin 226 move along the corresponding guide holes 232 on the two drive disks 231 respectively. Bushings 235 are welded on the mutually back-to-back end faces of the two drive disks 231. The bushings 235 are cylindrical structures with built-in splines. The two bushings 235 are coaxial with the disk body 21 and are arranged symmetrically.

[0047] It should be emphasized that in the mating plate 2, when the return spring 225 is in the reset state, the sliding part 221 cooperates with the radial groove 212 to make the return spring 225 in a relatively closed space. The corresponding assembly and cooperation of the two drive plates 231 and the two bearings 24 makes the interior of the center hole 211 relatively closed. That is, the drive-containing part of the mating plate 2 is located in a relatively closed space, which helps to prevent large particles of sand and soil from entering the closed space during construction and causing drive obstruction, thereby ensuring smooth drive.

[0048] like Figure 2As shown, an inner support frame 4 is centrally installed inside the support tube 1. The inner support frame 4 is a cylindrical bearing with a seat. The outer wall of the inner support frame 4 is close to the inner wall of the support tube 1. The inner support frame 4 has four screw holes evenly distributed around its circumference. The screw holes extend radially on the outer cylindrical wall of the inner support frame 4. The support tube 1 has four round holes that correspond one-to-one with the four screw holes. By passing screws through the round holes and tightening them into the corresponding screw holes, the inner support frame 4 can be detachably fixed inside the support tube 1. A corresponding insertion shaft 3 is rotatably mounted on the inner support frame 4, with the inner support frame 4 positioned centrally on the insertion shaft 3. The insertion shaft 3 can be splined into the bushing 235. It should be noted that the length of the insertion shaft 3 matches the length of the support tube 1. The inner support frame 4 and the insertion shaft 3 can be pre-assembled within the support tube 1 to form a combined assembly. Assuming the entire assembly is usable and can be used repeatedly, after one pre-assembly, the assembly can maintain its overall state regardless of whether the inclined support structure is assembled or disassembled, eliminating the need for frequent disassembly and reassembly. When the connecting plate 2 is connected between two support tubes 1, the insertion shaft 3 is rotated and adjusted to align the insertion shaft 3 within the two support tubes 1 with the two bushings 235 on the connecting plate 2, allowing the insertion shaft 3 to be simultaneously inserted into the bushings 235. While multiple support tubes 1 are connected in series via the connecting plate 2, multiple connecting plates 2 are axially connected via the insertion shaft 3.

[0049] like Figure 2 , Figure 4 and Figure 10 As shown, the drive end 5 includes an embedded cylinder 51 that is installed inside the support pipe 1 and fixed to the flange. The embedded insertion fit between the embedded cylinder 51 and the support pipe 1 provides an overlap section to ensure the joint strength. The embedded cylinder 51 is provided with a flange that mates with the flange of the support pipe 1. The flange of the embedded cylinder 51 has eight flange holes that correspond to the eight waist-shaped holes on the flange of the support pipe 1. Both the flange of the embedded cylinder 51 and the support pipe 1 have four bolt holes for locking with bolts. A screw seat 52 is welded inside the inner sleeve 51. A lead screw 53 is rotatably mounted on the screw seat 52. A connecting sleeve 54 is welded to one end of the lead screw 53. The lead screw 53 and the connecting sleeve 54 are coaxially arranged with the inner sleeve 51. The connecting sleeve 54 is key-fitted onto the insertion shaft 3 located inside the support tube 1 assembled with the drive end 5. In order to facilitate the rotation of the lead screw 53, a hexagonal hole is opened at the end of the lead screw 53 that is biased to protrude from the support tube 1, so that it can be used with a special hexagonal wrench.

[0050] like Figure 2 , Figure 5 , Figure 11 and Figure 12As shown, the movable end 6 and the driving end 5 are respectively located at both ends of the inclined support structure. The movable end 6 includes a movable cylinder 61 that is slidably fitted inside the support tube 1. A bearing seat 62 is welded inside the movable cylinder 61. A sliding sleeve 63, coaxially arranged with the movable cylinder 61, is rotatably mounted on the bearing seat 62. The sliding sleeve 63 is key-fitted onto the insertion shaft 3. The movable cylinder 61 also has a flange, and eight corresponding oblong holes are opened on the flange of the movable cylinder 61. Four screws 64 are welded to the flange of the movable cylinder 61, and the four screws 64 are slidably fitted into the four bolt holes on the flange of the support tube 1. Each screw 64 is threaded with two nuts, and the two nuts are distributed on both sides of the flange of the support tube 1. The screw 64 can be fixed to the flange of the support tube 1 by the two nuts. The flexible end 6 is used to compensate for and adjust the overall length of the inclined support structure, so that the two ends of the inclined support structure can be fixed to the lower support 71 and the upper support 72. Before the screw 64 is fixed, the flexible cylinder 61 can slide and extend within the support pipe 1, so that the length can be adjusted. After the adjustment is completed, the screw 64 can be fixed to the flange of the support pipe 1. It should be added that in order to ensure the strength of the connection between the flexible end 6 and the support pipe 1, the flexible cylinder 61 can be set with an effective length of embedded overlap with the support pipe 1. When adjusting the length, it should be ensured that the length of the flexible cylinder 61 embedded in the support pipe 1 is not less than the effective length.

[0051] The inclined support structure is fixedly assembled. By default, each support tube 1 is pre-assembled with an inner support frame 4 and a plug shaft 3. Multiple support tubes 1 can be selected for assembly according to the length of the inclined support. The thickness of the plate body 21 of the multiple docking plates 2 used for docking must be estimated within the overall length. In addition, through estimation, it is also necessary to ensure that the effective adjustment length of the movable end 6 meets the requirements of the length of the inclined support.

[0052] During assembly, multiple support tubes 1 are sequentially connected and joined together via the docking plate 2. During docking, the two locking blocks 222 of each locking assembly 22 on the docking plate 2 pass through the corresponding oblong holes on the flanges of the two support tubes 1. Then, the drive end 5 is connected and installed at the flange end of one support tube 1, and the flanges of both the inner sleeve 51 and the support tube 1 are fixed with bolts. Next, the movable end 6 is connected and installed at the flange end of the other support tube 1. Subsequently, the screw 53 is turned by a wrench, and the screw 53 drives all the plug shafts 3 and the drive shaft 23 to rotate synchronously through the docking sleeve 54. The drive shaft 23 then drives the moving pin 226 to move along the guide hole 232 synchronously through the two drive plates 231, so that the sliding part 221 and the guide rod 224 of each locking assembly 22 are facing the plate body 21. The center slides, then the oblong hole on the support pipe 1 is snapped into the snap-fit ​​seam 223. Each docking plate 2 uses eight snap-fit ​​blocks 222 to radially fix and clamp the flange of the support pipe 1 flange at the oblong hole, and axially clamps and limits the flange of the support pipe 1 between the end face of the plate body 21 and the eight snap-fit ​​blocks 222. The docking plate 2 achieves all-round fixed docking of two support pipes 1, so that multiple support pipes 1 can be integrated and quickly assembled. When disassembling, only the screw 53 needs to be turned in the reverse direction. This solves the problem of cumbersome disassembly and low efficiency caused by the use of a large number of bolts to fix multiple support pipes 1 during existing assembly. It also solves the problem that bolted connections between multiple support pipes 1 are prone to loosening during subsequent construction, resulting in a decrease in the strength and stability of the diagonal support. After the docking plate 2 completes the docking and fixing of the support pipes 1, the diagonal support structure is pre-assembled. When all components are transported to the construction site, all pre-assembly work can be completed on the construction site.

[0053] In addition, such as Figures 1 to 13 As shown, the present invention also provides a construction method for a deep foundation pit combined steel pipe inclined support structure, including the following steps: S1, determining the position, angle and length of each inclined support according to the scope of the deep foundation pit.

[0054] S2. Precast the upper support 72 and the corresponding lower support 71 according to each determined inclined support position.

[0055] S3. Select the corresponding support pipe 1 for each diagonal support position and pre-assemble it into a diagonal support structure.

[0056] S4. Hoist the inclined support structure to the corresponding inclined support position, located between the lower support 71 and the upper support 72. Specifically, through hoisting, place the drive end 5 and the movable end 6 at the lower support 71 and the upper support 72 respectively. While maintaining the hoisting state, first fix the flanges of both the inner tube 51 and the support tube 1 to the lower support 71 with bolts, keeping them in a state that is not completely locked, so that fine adjustments can be made when fixing the movable end 6.

[0057] S5. Adjust the movable end 6 so that both ends of the inclined support structure are supported on the lower support 71 and the upper support 72 respectively and then fixed. While still in the hoisting state, slide and adjust the movable cylinder 61 so that the flange of the movable cylinder 61 is in full contact with the upper support 72. Then, fully lock the drive end 5. Next, fix the screw 64 to the flange of the support pipe 1 with a nut. During the process of locking the screw 64, make fine adjustments to ensure that the movable cylinder 61 and the upper support 72 are tightly pressed together. Finally, lock the flange of the movable cylinder 61 to the upper support 72 with bolts.

[0058] S6. Carry out the construction of the support plate 75. After the support plate 75 has cured to the required strength, hoist and remove the inclined support structure. The support plate 75 is located below the capping beam 74 and is poured between the support pile 73 and the building foundation 76.

[0059] It is important to emphasize that, in order to ensure the safety of construction, the principle of symmetrical construction should be followed during the installation and dismantling of the inclined support structure; in addition, installation and dismantling must be carried out only after ensuring that the poured structure has reached the curing strength standard.

[0060] After the two ends of the inclined support structure are fixed to the lower support 71 and the upper support 72, the multiple connecting discs 2 and multiple plug shafts 3 connected alternately along the axis, together with the driving end 5 and the movable end 6 at both ends, not only realize the axial connection of multiple support pipes 1, but also form a support skeleton that forms internal support for multiple support pipes 1. This makes up for the defect of reduced bending resistance caused by the lengthening of multiple support pipes 1 due to docking, improves the overall bending strength of the inclined support structure, further enhances the stability and reliability of the inclined support, reduces the probability of the support pipes 1 being scrapped due to deformation, and improves the recyclability of the support pipes 1.

[0061] It should also be emphasized that although the inclined support structure provided by this invention increases the complexity of the structure compared with the existing steel pipe assembly using bolted connections, the inclined support structure provided by this invention is a modular assembly structure. Its components can be mass-produced according to unified standards and are designed to be recyclable, making it easy to reuse. In addition, it significantly improves the convenience of disassembly and assembly, and enhances the stability and reliability of the inclined support for deep foundation pits, especially improving the safety of construction. It has good practicality and reliable use value.

[0062] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0063] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "connected," "installed," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0064] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and the devices and structures not described in detail should be understood as being implemented in a manner common to the art; any possible variations and modifications made by those skilled in the art without departing from the technical solution of the present invention, or equivalent embodiments with equivalent changes, do not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A composite steel pipe inclined support structure for deep foundation pits, characterized in that, include: Multiple support pipes, each with flanges at both ends; A docking plate; multiple support tubes are connected in series through the docking plate; the docking plate includes a plate body with both ends embedded in the flange ports of the two support tubes, and multiple snap-fit ​​components are mounted on the side wall of the plate body along the circumferential direction and are all slidably arranged along the radial direction of the plate body. A drive shaft is installed through the center of the plate body and rotates with it on the same axis. The drive shaft is used to drive the multiple snap-fit ​​components to slide synchronously. The plug shaft can be keyed to both ends of the drive shaft and placed inside the support tube. An inner support frame is detachably installed inside the support tube, and the plug shaft is rotatably mounted on the corresponding inner support frame. The drive end is detachably fixed to the flange end of the left support tube and is engaged with the plug shaft inside the left support tube. And the flexible end, which is axially adjustable and mounted on the flange end of the right end support pipe; The drive end is used to drive multiple plug-in shafts and multiple drive shafts to rotate synchronously, and drive multiple snap-fit ​​components on each docking plate to snap into the corresponding flange holes on the flanges of the two end support tubes, and the flanges of the two support tubes are tightly attached to both ends of the plate body. The snap-fit ​​assembly includes a sliding part that slides radially along the disc body. Snap-fit ​​blocks are fixedly positioned on the sliding part at both axial ends of the disc body. A snap-fit ​​seam is formed between the snap-fit ​​blocks and the end face of the disc body. The flange holes on the support tube, corresponding to multiple snap-fit ​​assemblies, are oblong holes, through which the snap-fit ​​blocks can pass. When the drive shaft moves the snap-fit ​​assembly, causing the sliding part to slide closer to the center of the disc body, the oblong holes snap into the snap-fit ​​seam. The side wall of the disc body is provided with a plurality of radial grooves corresponding to a plurality of buckle assemblies, and each radial groove is provided with a stepped hole extending radially; the buckle assembly also includes a guide rod fixed to the sliding part, the guide rod is slidably installed in the stepped hole, and a return spring is sleeved on the guide rod, with the two ends of the return spring fixed to the sliding part and the step of the stepped hole respectively. The disc body has a central hole at its center; the drive shaft includes a connecting post passing through the central hole, with drive discs fixed at both ends of the connecting post, and the two drive discs are rotatably mounted at both ends of the disc body; the stepped hole communicates with the central hole, and the guide rod passes through the stepped hole and extends into the central hole; the buckling assembly also includes a movable pin fixed to one end of the guide rod extending into the central hole; multiple guide holes corresponding to and cooperating with multiple buckling assemblies are provided on the mutually facing end faces of the two drive discs, and the two ends of the movable pin move along the corresponding guide holes on the two drive discs respectively.

2. The deep foundation pit composite steel pipe inclined support structure according to claim 1, characterized in that: The drive end includes an inner cylinder embedded in the support tube and fixed to the flange. A lead screw is coaxially arranged and threadedly mounted inside the inner cylinder. One end of the lead screw is fixed to a connecting cylinder that is key-fitted with the plug shaft.

3. The deep foundation pit composite steel pipe inclined support structure according to claim 1, characterized in that: The movable end includes a movable cylinder that slides within the support tube, and a sliding sleeve is coaxially arranged and rotatably installed inside the movable cylinder, with the sliding sleeve sleeved onto the insertion shaft.

4. The deep foundation pit composite steel pipe inclined support structure according to claim 1, characterized in that: The drive shaft also includes two bushings, which are symmetrically arranged and fixed on opposite end faces of the two drive discs; the plug shaft is plugged into the bushings.

5. The deep foundation pit composite steel pipe inclined support structure according to claim 3, characterized in that: The movable end also includes multiple screws fixed on the movable cylinder and slidingly engaged with the flange of the support pipe. The movable end can be fixed on the flange of the support pipe by means of nuts and screws.

6. The deep foundation pit composite steel pipe inclined support structure according to claim 1, characterized in that: Both sides of the disc body are fixed with bearing bushes that cooperate with the drive disc on the same side. The drive disc is located inside the bearing bushes, and multiple balls that roll and cooperate with the bearing bushes are circumferentially distributed and embedded on the side wall of the drive disc.

7. A construction method for a deep foundation pit composite steel pipe inclined support structure, wherein when using the deep foundation pit composite steel pipe inclined support structure as described in any one of claims 1-6 for deep foundation pit inclined support construction, characterized in that, Includes the following steps: S1. Based on the extent of the deep foundation pit, determine the location, angle, and length of each inclined support; S2. Precast the upper support pier and the corresponding lower support pier according to each determined diagonal support position; S3. Select the corresponding support pipe for each diagonal support position and pre-assemble it into a diagonal support structure; S4. Hoist the inclined support structure to the corresponding inclined support position, which is located between the lower support pier and the upper support pier; S5. After adjusting the flexible end, the two ends of the inclined support structure are respectively supported on the lower support and the upper support and then fixed. S6. Carry out the replacement support plate construction. After the strength is reached, hoist and dismantle the diagonal support structure.

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