Steel sheet pile and cement-soil mixing pile wall combined supporting structure and construction method thereof

Abstract

This application relates to the technical field of foundation pit support structures, and in particular to a combined support structure of steel sheet piles and cement-soil mixing piles and its construction method. It includes multiple vertically arranged mixing piles surrounding the foundation pit. Each mixing pile contains a steel frame, which is spaced apart on the mixing pile. Steel sheet piles are also installed on the side of each mixing pile closest to the foundation pit. Multiple steel sheet piles are arranged, with adjacent steel sheet piles interconnected and surrounding the foundation pit. Connecting rods connect the steel sheet piles and the mixing piles, with both ends of the connecting rods connected to the steel frame and the steel sheet piles respectively via fasteners. Water-retaining components are installed between adjacent steel frame sections, with each water-retaining component inserted into two adjacent steel frame sections on its sides. This application enhances the waterproofing effect of the foundation pit support structure and improves the sealing performance of the support structure.

Description

Technical Field

[0001] This application relates to the technical field of foundation pit support structures, and in particular to a combined support structure of steel sheet piles and cement-soil mixing pile walls and its construction method. Background Technology

[0002] During the construction of the foundation pit, it is necessary to pre-set the foundation pit support structure. The cement-soil mixing pile wall adopts the SMW method pile. The SMW method pile is constructed by drilling to a certain depth on site with a multi-axis drilling and mixing machine. At the same time, cement-based reinforcing agent is sprayed at the drill bit and repeatedly mixed with the foundation soil. The construction units are constructed by overlapping and splicing. Then, before the cement-soil mixture hardens, H-beams are inserted as stress reinforcement materials. Once the cement hardens, a continuous underground wall with a certain strength is formed.

[0003] In actual construction, the upper soil layer is often peat soil with a high porosity and high water content. When mixing piles are constructed in the peat soil layer, cement and soil can easily enter the pores, affecting the sealing of the mixing piles and causing water seepage in the foundation pit during later construction. Summary of the Invention

[0004] To enhance the waterproofing effect and improve the sealing performance of the foundation pit support structure, this application provides a combined support structure of steel sheet piles and cement-soil mixing pile walls and its construction method.

[0005] On the one hand, the combined support structure of steel sheet pile and cement-soil mixing pile wall provided in this application adopts the following technical solution: A combined steel sheet pile and cement-soil mixing pile wall support structure includes multiple vertically arranged mixing piles surrounding a foundation pit. Each mixing pile contains a steel frame, which is spaced apart on the mixing pile. Steel sheet piles are also installed on the side of each mixing pile closest to the foundation pit. Multiple steel sheet piles are arranged, with adjacent steel sheet piles interconnected and surrounding the foundation pit. Connecting rods connect the steel sheet piles and the mixing piles, with both ends of the connecting rods connected to the steel frame and the steel sheet pile respectively via fasteners. Water-retaining components are installed between adjacent steel frames, with each water-retaining component inserted into two adjacent steel frames on its sides.

[0006] By adopting the above technical solution, the mixing piles can play a major supporting role, resisting lateral loads around the foundation pit. The steel frame inside the mixing piles increases the structural strength and integrity of the mixing piles, enabling them to withstand greater loads. After the mixing piles near the peat layer solidify, their sealing performance may be affected. Steel sheet piles can further enhance the waterproofing of the foundation pit, and the connection between the water-retaining components and the steel frame also increases the waterproofing performance of the mixing piles. The connecting rods can fix the steel sheet piles, increasing their stability. The mixing piles, steel frame, and water-retaining components form a waterproof support structure, while the steel sheet piles themselves form another waterproof support structure. This double-layer support structure ensures the stability of the support around the foundation pit while reducing water seepage within the pit.

[0007] Optionally, the steel frame includes two parallel first wing plates and second wing plates, with the second wing plate located on the side closer to the foundation pit. A connecting plate is fixedly connected between the first wing plate and the second wing plate. The water-blocking assembly includes a first baffle and a second baffle. The first baffle and the first wing plate are inserted into each other, and the second baffle is inserted into the second wing plate of the adjacent steel frame. A first connecting part is fixedly provided on the side of the first baffle close to the second baffle, and a second connecting part is provided on the side of the second baffle close to the first baffle. The first connecting part and the second connecting part are interlocked with each other. The first baffle and the second baffle are slidably connected. The mixing pile has a moving groove for the first baffle to move.

[0008] By adopting the above technical solution, the steel frame composed of the first wing plate, the second wing plate, and the connecting plate has strong structural strength and can withstand large lateral loads. Two adjacent steel frames can be connected to each other between the first and second baffles. The interlocking of the first and second connecting parts increases the connection strength between the first and second baffles. When the first baffle is subjected to a large lateral load, it undergoes slight deformation and moves towards the second baffle within the moving groove, thus enabling the water-blocking assembly to form a buffering effect.

[0009] Optionally, the first connecting part is provided with a protrusion, and the second connecting part is provided with a groove. The protrusion and the groove are engaged with each other, and there is a gap between the protrusion and the inner bottom wall of the groove.

[0010] By adopting the above technical solution, the interlocking fit between the protrusion and the groove can increase the contact area between the first connecting part and the second connecting part, making the connection between the first connecting part and the second connecting part more compact and able to withstand greater lateral loads.

[0011] Optionally, the first wing plate is further provided with an adjustment frame on the side near the second wing plate. The adjustment frame includes an active part and a driven part. The active part is inserted into the first connecting part. The second wing plate is provided with a fixing member. The driven part is hinged to the fixing member. The end of the connecting rod away from the steel sheet pile passes through the driven part, and the connecting rod is provided with a stop block. The stop block abuts against the driven part.

[0012] By adopting the above technical solution, when the first baffle is subjected to a large lateral load and moves, the first baffle drives the active part to move through the first connecting part. The active part and the driven part form a lever principle, and the driven part rotates on the fixed part. The driven part drives the connecting rod to slide along its own axis through the abutment block, thereby further tightening the steel sheet pile and increasing the stability of the steel sheet pile.

[0013] Optionally, the bottom of the sheet pile is further provided with an anchoring assembly, and multiple sets of the anchoring assembly are arranged around the foundation pit. Each set of the anchoring assembly includes an anchor head, an anchor rod, and a pad. One end of the anchor head is fixedly connected to the anchor rod, and the other end of the anchor head extends into the mixing pile and is fixedly connected to the mixing pile. The end of the anchor rod away from the anchor head passes through the sheet pile and the pad. The pad abuts against the sheet pile, and the anchor rod and the pad are fixedly connected by fasteners.

[0014] By adopting the above technical solution, the anchoring assembly can provide stable support for the bottom of the sheet pile. The anchor head is formed by pouring and solidifying cement-soil, and remains in the soil layer to form a stable anchor body, which provides a traction foundation for the anchor rod. The end of the anchor rod away from the anchor head is connected to the pad plate by fasteners, and the pad plate can increase the stress area of ​​the sheet pile.

[0015] Optionally, a corner brace assembly is provided between adjacent pads. The corner brace assembly includes abutment seats, abutment rods, and an adjusting member. Two abutment seats are provided and are detachably connected to two adjacent pads respectively. Two abutment rods are provided and are fixedly connected to two abutment seats respectively. The two ends of the adjusting member are threadedly connected to the opposite ends of the two abutment rods respectively.

[0016] By adopting the above technical solution, the corner bracing assembly can provide support for the sheet piles at the four corners of the foundation pit. By rotating the adjusting component, the two abutment rods will move closer or further apart. The abutment rods act on the pads through the abutment seats, thereby adjusting the stability between adjacent pads and further increasing the integrity and stability of the sheet piles.

[0017] Optionally, a capping beam is provided on the top of the mixing pile.

[0018] By adopting the above technical solution, the capping beam can connect all the mixing piles, thereby increasing the stability and integrity between the mixing piles. The capping beam can guide the load from the superstructure to the mixing piles, and then transfer it to the foundation through the mixing piles, improving the bearing capacity of the entire project. Furthermore, the capping beam can increase the stiffness and strength of the mixing piles and prevent their deformation, thus improving the interaction between the mixing piles and the soil layer.

[0019] On the other hand, the construction method of the combined support structure of steel sheet pile and cement-soil mixing pile wall provided in this application adopts the following technical solution: including the following steps: S1. After determining the location of the foundation pit, excavate the guide trench; S2, the drilling rig drills holes in the soil layer under the guide trench and injects cement soil to form multiple mixing piles, and the mixing piles are spliced ​​together to surround the foundation pit; S3, After applying friction-reducing agent to the surface of the steel frame, insert it into the mixing pile and correct the verticality of each steel frame; S4. After splicing the steel sheet piles in sequence, insert them into the side of the mixing pile near the foundation pit, so that multiple steel sheet piles form the shape of the foundation pit. S5. After the cement soil inside the mixing pile has solidified, the steel sheet pile is excavated to form the soil in the foundation pit. Reinforcing bars and formwork are erected on the top of the mixing pile. Cement soil is poured inside the formwork. After the cement soil solidifies, the cap beam is formed. S6, Place the pad against the sheet pile and install the corner brace assembly to fix the position of the pad; S7. Drill holes at an angle downwards into the pad and through the pad and sheet pile. Pour cement soil into the holes and insert anchor rods. After the cement soil solidifies, it forms an anchor head. The anchor rods extend out of the pad and are then fastened with fasteners.

[0020] Optionally, in S3, the steel frame is inserted into the mixing pile in a one-in-one-out manner, and the four corners of the foundation pit are inserted in a close-fitting manner.

[0021] By adopting the above technical solutions, the correspondence between the steel frame and the mixing piles determines the structural strength, cost, and construction difficulty of the mixing pile wall. A close-fitting method results in a more stable mixing pile wall structure, but it is costly and difficult to construct. A one-insertion-one-jump method may result in a mixing pile wall structure with lower structural strength than the close-fitting method. Based on the construction situation, the four corners of the foundation pit experience greater lateral loads; therefore, a close-fitting method is used at the four corners, while a one-insertion-one-jump method is used on the other sides. This construction approach ensures the structural strength of the mixing piles while increasing construction efficiency and reducing costs.

[0022] Optionally, before the S5 mixing pile solidifies, the first baffle is inserted into the first wing plate, the second baffle is inserted into the second wing plate of the adjacent steel frame, and the first connecting part is engaged with the second connecting part. The active part of the adjusting frame is inserted into the first connecting part, the fixed frame is inserted into the second wing plate of the same steel frame, and the connecting rod is passed through the driven part of the adjusting frame, the second wing plate and the sheet pile, so that the abutment on the connecting rod abuts against the driven part, and the end of the connecting rod away from the abutment is fastened by fasteners.

[0023] By adopting the above technical solution, the steel frame and the mixing pile are connected in a one-insertion-one-jump configuration, with a first baffle and a second baffle between adjacent steel frames. This serves both to block water and increase the connection strength between adjacent steel frames. The steel frame is installed first, followed by the water-blocking and adjusting components. The steel frame provides the installation foundation.

[0024] In summary, this application includes at least one of the following beneficial technical effects: 1. The mixing piles and steel frame form a load-bearing support structure to resist lateral loads. The structure formed by the steel frame and water-retaining components can increase the waterproof effect of the mixing pile wall and can play a water-retaining role for the part of the mixing pile located in the peat layer. 2. Steel sheet piles can provide waterproofing for the foundation pit, and through anchoring components, corner bracing components, and connecting rods, steel sheet piles also provide a certain degree of support for the foundation pit; 3 When the first baffle is subjected to a large lateral load, the first baffle deforms and displaces within the moving groove, and then the connecting rod is driven by the adjusting frame to tighten the steel sheet pile, thereby enhancing the stability of the steel sheet pile. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of an embodiment of a combined support structure of steel sheet pile and cement-soil mixing pile wall according to this application; Figure 2 This application Figure 1 Enlarged view of part A; Figure 3 This is a schematic diagram of the water-retaining component and the regulating component of an embodiment of a combined support structure of steel sheet pile and cement-soil mixing pile wall according to this application; Figure 4 This application Figure 3 Enlarged view of part B; Figure 5 This is a schematic diagram of the anchoring component of an embodiment of a combined support structure of steel sheet pile and cement-soil mixing pile wall according to this application; Figure 6 This application Figure 1 Enlarged view of part C; Figure 7This is a schematic diagram of the steel frame arrangement in an embodiment of the construction method of a combined support structure of steel sheet piles and cement-soil mixing pile walls according to this application.

[0026] Explanation of reference numerals in the attached drawings: 1. Mixing pile; 11. Moving trough; 2. Steel sheet pile; 3. Water-retaining assembly; 31. First baffle; 311. First insertion part; 312. First connecting part; 313. Protrusion; 32. Second baffle; 321. Second insertion part; 322. Second connecting part; 323. Groove; 4. Adjustment assembly; 41. Adjustment frame; 411. Active part; 412. Driven part; 42. Fixing member; 43. Connecting rod; 431. Abutment block; 44. Horizontal plate; 5. Angle brace assembly; 51. Abutment seat; 52. Abutment rod; 53. Adjustment member; 531. Rotating rod; 6. Anchoring assembly; 61. Anchor head; 62. Anchor rod; 63. Pad; 64. Pad seat; 7. Steel frame; 71. First wing plate; 72. Second wing plate; 73. Connecting plate; 8. Crown beam. Detailed Implementation

[0027] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.

[0028] The following is in conjunction with the appendix Figure 1 -Appendix Figure 7 This application will be described in further detail.

[0029] This application discloses a combined support structure of steel sheet piles and cement-soil mixing pile walls, referring to... Figure 1 and Figure 2 The structure includes mixing piles 1, sheet piles 2, water-retaining components 3, adjusting components 4, corner bracing components 5, and anchoring components 6. The mixing piles 1 are vertically installed, formed by pouring and solidifying cement-soil mixture. The mixing piles 1 bear the soil load around the foundation pit. A steel frame 7 is installed inside the mixing piles 1 to increase its structural strength. The mixing piles 1 and sheet piles 2 are spaced apart. The sheet piles 2 are vertically installed Larssen sheet piles, and adjacent sheet piles 2 are interlocked, providing good waterproofing. Water-retaining components 3 are installed between adjacent steel frames 7, with multiple sets distributed around the foundation pit. These components increase the waterproofing between the mixing piles 1. The sheet piles 2 and steel frames 7 are connected by adjusting components 4, which enhance the structural stability of the sheet piles 2. Corner bracing components 5 are located at the four corners of the foundation pit, increasing the structural stability of the sheet piles 2 at the four corners. Anchoring components 6 increase the structural stability of the bottom of the sheet piles 2.

[0030] Reference Figure 2 and Figure 3 The steel frame 7 includes a first wing plate 71, a second wing plate 72, and a connecting plate 73. The two ends of the connecting plate 73 are fixedly connected to the first wing plate 71 and the second wing plate 72 respectively, forming an H-shaped cross-section. The second wing plate 72 is located on the side of the first wing plate 71 closest to the foundation pit. The steel frame 7 is inserted into the mixing pile 1 and forms an integral part with the solidified mixing pile 1. A capping beam 8 is fixedly installed on the steel frame 7. The capping beam 8 is integrally formed by pouring cement and soil. The portion of the steel frame 7 that passes through the capping beam 8 is wrapped with plastic film for easy removal of the steel frame 7 later.

[0031] Reference Figure 2 and Figure 3 The water-blocking component 3 is vertically arranged and includes a first baffle 31 and a second baffle 32. The second baffle 32 is located on the side closer to the foundation pit. The first baffle 31 is fixedly provided with a first insertion part 311, which is inserted into the first wing plate 71. The second baffle 32 is fixedly provided with a second insertion part 321, which is inserted into the second wing plate 72 of the adjacent steel frame 7. The first baffle 31 is provided with a first connecting part 312 on the side closer to the second baffle 32, and the second baffle 32 is provided with a second connecting part 322 on the side closer to the first baffle 31. The first connecting part 312 and the second connecting part 322 are interlocked with each other. The first connecting part 312 is provided with a plurality of protrusions 313 spaced apart along its own length direction. The second connecting part 322 is provided with a plurality of grooves 323 that mate with the protrusions 313, and there is a gap between the protrusions 313 and the bottom wall of the grooves 323. A movable groove 11 is provided at the top of the mixing pile 1, and the first baffle 31 can move within the movable groove 11 along the side near the second baffle 32. To reduce the entry of cement soil into the groove 323, a bottom plate (not shown in the figure) is provided at the bottom of the first connecting part 312 and the second connecting part 322, and the bottom plate wraps around the first connecting part 312 and the second connecting part 322. The contact parts of the water-blocking component 3 with the crown beam 8 and the mixing pile 1 are all wrapped with a layer of plastic film to facilitate the removal of the water-blocking component 3 later.

[0032] Reference Figure 3 and Figure 4Multiple sets of adjusting components 4 and water-blocking components 3 are provided correspondingly. The adjusting component 4 includes an adjusting frame 41, a fixing member 42, a connecting rod 43, and a horizontal plate 44. The two ends of the adjusting frame 41 are respectively fixedly provided with an active part 411 and a driven part 412. The active part 411 is inserted into the first connecting part 312. The fixing member 42 is inserted into the second wing plate 72 of the same type of steel frame 7. The driven part 412 is hinged to the fixing member 42. The connecting rod 43 is respectively passed through the driven part 412, the second wing plate 72, and the steel sheet pile 2. One end of the connecting rod 43 is provided with a stop block 431, which abuts against the driven part 412. The other end of the connecting rod 43 is fixedly connected to the horizontal plate 44 by fasteners. There are four horizontal plates 44, all of which abut against the steel sheet pile 2.

[0033] Reference Figure 5 Anchoring components 6 are located at the bottom of sheet piles 2. Multiple sets of anchoring components 6 are arranged around the perimeter of the foundation pit. Each set of anchoring components 6 includes an anchor head 61, an anchor rod 62, and a pad 63. The anchor head 61 is a cement-solidified cylinder. The anchor head 61 is inclined downward. The anchor head 61 is coaxially fixedly connected to the anchor rod 62. The anchor rod 62 is a steel round rod. The end of the anchor rod 62 away from the anchor head 61 passes through the sheet pile 2 and the pad 63. The pad 63 is abutted by a pad seat 64 for increasing the bearing area of ​​the pad 63. The anchor head 61 and the pad seat 64 are fixedly connected by fasteners.

[0034] Reference Figure 6 The corner brace assembly 5 includes abutment seats 51, abutment rods 52, and adjusting members 53. Two abutment seats 51 are provided, each detachably connected to two adjacent pads 63. Two abutment rods 52 are provided, each fixedly connected to one of the two abutment seats 51. The adjusting member 53 is cylindrical, with both ends threadedly connected to the opposite ends of the two abutment rods 52. Multiple rotating rods 531 are fixedly provided on the peripheral sidewall of the adjusting member 53.

[0035] The implementation principle of this application embodiment is as follows: When the mixing pile 1 in the peat layer leaks, the leaking water will be blocked by the sheet pile 2, thereby reducing the amount of groundwater entering the foundation pit. The mixing pile 1 provides the main and stable support for the foundation pit, and the sheet pile 2 increases the waterproof performance of the foundation pit.

[0036] The water-blocking component 3 can increase the waterproof effect between the steel frames 7 and increase the structural connection strength between adjacent steel frames 7.

[0037] When a lateral load is applied to the first baffle 31 in the direction of the foundation pit, the first baffle 31 undergoes slight deformation and can move slightly within the moving groove 11. The first connecting part 312 and the second connecting part 322 will gradually overlap, and the first connecting part 312 will also drive the adjusting frame 41 to rotate, causing the driven part 412 to rotate and apply a force away from the foundation pit to the abutment block 431, so that the connecting rod 43 slides along its own length direction, thereby strengthening the fixation of the sheet pile 2 and increasing the support effect of the sheet pile 2.

[0038] The anchoring component 6 can increase the support effect at the bottom of the sheet pile 2. The anchoring rod 62 can adjust the fastening effect of the anchoring component 6 on the sheet pile 2 by rotating the fastener.

[0039] The corner bracing assembly 5 can support the sheet piles 2 at the four corners of the foundation pit. By rotating the rotating rod 531, the adjusting member 53 rotates around its own axis, thereby causing the abutment rods 52 at both ends of the rotating member to move closer or further apart, thus adjusting the stability of the four corners of the sheet piles 2.

[0040] This application discloses a construction method for a combined support structure of steel sheet piles and cement-soil mixing pile walls, which includes the following steps: S1. After determining the location of the foundation pit, excavate the guide trench; S2, the drilling rig drills holes in the soil layer under the guide trench and injects cement soil to form multiple mixing piles 1, and the mixing piles 1 are spliced ​​together and surround the foundation pit. S3, after applying a friction-reducing agent to the surface of the steel frame 7, insert it into the mixing pile 1, and correct the verticality of each steel frame 7, referring to... Figure 7 The steel frame 7 is inserted into the mixing pile 1 in a one-in-one-out manner, and the four corners of the foundation pit are in a close-insertion manner. S4, after splicing the steel sheet piles 2 in sequence, insert them into the side of the mixing pile 1 near the foundation pit, so that multiple steel sheet piles 2 form the shape of the foundation pit; S5, insert the first baffle 31 into the first wing plate 71, insert the second baffle 32 into the second wing plate 72 of the adjacent steel frame 7, and snap the first connecting part 312 and the second connecting part 322 together. Insert the active part 411 of the adjusting frame 41 into the first connecting part 312. Insert the fixing part 42 into the second wing plate 72 of the same steel frame 7. Pass the connecting rod 43 through the driven part 412 of the adjusting frame 41, the second wing plate 72 and the steel sheet pile 2, so that the abutment 431 on the connecting rod 43 abuts against the driven part 412. The end of the connecting rod 43 away from the abutment 431 is fastened by a fastener. Insert the fixing strip for forming the moving groove 11 downward into the side of the first baffle 31 near the second baffle 32. The fixing strip is wrapped with plastic film. S6. After the cement soil in the mixing pile 1 has solidified, the steel sheet pile 2 is excavated to form the soil in the foundation pit. Reinforcing bars and formwork are erected on the upper part of the mixing pile 1. Cement soil is poured in the formwork. After the cement soil solidifies, the crown beam 8 is formed. The fixing strip is removed so that the crown beam 8 and the mixing pile 1 form a movable groove 11. S7, place the pad 63 against the sheet pile 2, and install the corner brace assembly 5 to fix the position of the pad 63; S8, a hole is driven obliquely downward on the pad 63 and passes through the pad 63 and the sheet pile 2. Cement soil is poured into the hole and the anchor rod 62 is inserted. After the cement soil solidifies, the anchor head 61 is formed. The anchor rod 62 extends out of the pad 63 and is then fastened with fasteners.

[0041] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A combined support structure of steel sheet piles and cement-soil mixing piles, comprising multiple mixing piles (1) vertically arranged around a foundation pit, wherein a steel frame (7) is provided inside each mixing pile (1), and the steel frame (7) is spaced apart on the mixing pile (1), characterized in that: A sheet pile (2) is also provided on the side of the mixing pile (1) near the foundation pit. Multiple sheet piles (2) are arranged around the foundation pit and adjacent sheet piles (2) are connected to each other. A connecting rod (43) is connected between the sheet pile (2) and the mixing pile (1). The two ends of the connecting rod (43) are respectively connected to the steel frame (7) and the sheet pile (2) by fasteners. A water-blocking component (3) is provided between adjacent steel frames (7). The two sides of the water-blocking component (3) are respectively inserted into two adjacent steel frames (7). The steel frame (7) includes two parallel first wing plates (71) and second wing plates (72), with the second wing plate (72) located on the side closer to the pit. A connecting plate (73) is fixedly connected between the first wing plate (71) and the second wing plate (72). The water-blocking assembly (3) includes a first baffle (31) and a second baffle (32). The first baffle (31) and the first wing plate (71) are inserted together, and the second baffle (32) is connected to the second wing plate (72) of the adjacent steel frame (7). 2) Insertion: The first baffle (31) is fixedly provided with a first connecting part (312) on the side near the second baffle (32), and the second baffle (32) is provided with a second connecting part (322) on the side near the first baffle (31). The first connecting part (312) and the second connecting part (322) are interlocked with each other. The first baffle (31) and the second baffle (32) are slidably connected. The mixing pile (1) is provided with a moving groove (11) for the first baffle (31) to move.

2. The combined support structure of steel sheet pile and cement-soil mixing pile wall according to claim 1, characterized in that: The first connecting part (312) is provided with a protrusion (313), and the second connecting part (322) is provided with a groove (323). The protrusion (313) and the groove (323) are engaged with each other, and there is a gap between the inner bottom wall of the protrusion (313) and the groove (323).

3. The combined support structure of steel sheet pile and cement-soil mixing pile wall according to claim 1, characterized in that: An adjustment frame (41) is provided on the side of the first wing plate (71) near the second wing plate (72). The adjustment frame (41) includes an active part (411) and a driven part (412). The active part (411) is inserted into the first connecting part (312). The second wing plate (72) is inserted into a fixing member (42). The driven part (412) is hinged to the fixing member (42). The end of the connecting rod (43) away from the sheet pile (2) passes through the driven part (412). The connecting rod (43) is provided with a stop block (431). The stop block (431) abuts against the driven part (412).

4. The combined support structure of steel sheet pile and cement-soil mixing pile wall according to claim 3, characterized in that: An anchoring assembly (6) is also provided at the bottom of the sheet pile (2), and multiple sets of the anchoring assembly (6) are arranged around the foundation pit. Each set of the anchoring assembly (6) includes an anchor head (61), an anchor rod (62) and a pad (63). One end of the anchor head (61) is fixedly connected to the anchor rod (62), and the other end of the anchor head (61) extends into the mixing pile (1) and is fixedly connected to the mixing pile (1). The end of the anchor rod (62) away from the anchor head (61) passes through the sheet pile (2) and the pad (63). The pad (63) abuts against the sheet pile (2), and the anchor rod (62) and the pad (63) are fixedly connected by fasteners.

5. The combined support structure of steel sheet pile and cement-soil mixing pile wall according to claim 4, characterized in that: An angle brace assembly (5) is provided between adjacent pads (63). The angle brace assembly (5) includes an abutment seat (51), an abutment rod (52), and an adjusting member (53). There are two abutment seats (51) and they are detachably connected to the two adjacent pads (63). There are two abutment rods (52) and they are fixedly connected to the two abutment seats (51) respectively. The two ends of the adjusting member (53) are threaded to the opposite ends of the two abutment rods (52).

6. The combined support structure of steel sheet pile and cement-soil mixing pile wall according to claim 1, characterized in that: The top of the mixing pile (1) is provided with a cap beam (8).

7. A construction method for a combined steel sheet pile and cement-soil mixing pile wall support structure, used for constructing the combined steel sheet pile and cement-soil mixing pile wall support structure as described in claim 5, characterized in that: Includes the following steps: S1. After determining the location of the foundation pit, excavate the guide trench; S2. Drill holes in the soil layer under the guide trench and inject cement soil to form multiple mixing piles (1), and the mixing piles (1) are spliced ​​together to surround the foundation pit; S3. Apply friction reducing agent to the surface of the steel frame (7) and insert it into the mixing pile (1), and correct the verticality of each steel frame (7); S4. Splice the steel sheet piles (2) in sequence and insert them into the side of the mixing pile (1) near the foundation pit, so that multiple steel sheet piles (2) surround the shape of the foundation pit; S5. After the cement soil in the mixing pile (1) solidifies, dig out the steel sheet piles (2) to form the soil in the foundation pit, erect steel bars and formwork on the upper part of the mixing pile (1), pour cement soil in the formwork, and form a cap beam (8) after the cement soil solidifies; S6. Place the pad plate (63) against the steel sheet pile (2) and install the corner brace assembly (5) to fix the position of the pad plate (63); S7, Drill holes at an angle downward on the pad (63) and through the pad (63) and the sheet pile (2), pour cement soil into the holes and insert anchor rods (62), and after the cement soil solidifies, form anchor heads (61), and the anchor rods (62) extend out of the pad (63) and are then fastened with fasteners.

8. The construction method of a combined support structure of steel sheet pile and cement-soil mixing pile wall according to claim 7, characterized in that: At S3, the steel frame (7) is inserted into the mixing pile (1) in a one-in-one-out ...

9. A construction method for a combined support structure of steel sheet piles and cement-soil mixing pile walls according to claim 7, characterized in that: Before the S5 mixing pile (1) solidifies, insert the first baffle (31) into the first wing plate (71), insert the second baffle (32) into the second wing plate (72) of the adjacent steel frame (7), and snap the first connecting part (312) with the second connecting part (322), insert the active part (411) of the adjusting frame (41) into the first connecting part (312), insert the fixing part (42) into the second wing plate (72) of the same steel frame (7), and pass the connecting rod (43) through the driven part (412), the second wing plate (72) and the sheet pile (2) of the adjusting frame (41), so that the abutment (431) on the connecting rod (43) abuts against the driven part (412), and the end of the connecting rod (43) away from the abutment (431) is fastened by fasteners.

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