Open cut tunnel bite pile support without counter-pulling steel formwork side wall and construction method

Abstract

This invention provides a method for constructing a sidewall without tie rods using interlocking pile support in open-cut tunnels. The method includes: setting foundation pre-embedded bolts; pouring foundation concrete; binding sidewall reinforcement; installing sidewall steel panels and supporting trusses; installing and debugging the sidewall formwork support system; installing and testing the anti-buoyancy system; installing and debugging a multi-target distance sensing steel formwork deformation monitoring system; pouring sidewall concrete; and treating construction joint waterproofing. This invention solves the problem of limited construction space for formwork trolleys in local tunnel construction sections by optimizing the formwork structure system. Compared to traditional large-volume steel formwork installation, it offers lower material costs, more flexible installation and adjustment, and superior anti-buoyancy stability, significantly improving the overall construction progress. Simultaneously, the operational efficiency of the construction joint waterproofing and formwork deformation monitoring system is also significantly improved. This construction technology demonstrates multiple technical advantages in practical applications, including high quality, high efficiency, and high returns, with outstanding application results.

Description

Technical Field

[0001] This invention relates to the field of tunnel sidewall casting, and in particular to the construction method of sidewall without tie steel formwork supported by interlocking piles in open-cut tunnels. Background Technology

[0002] With the continuous development of urban underground space, open-cut tunnels have been widely used in municipal engineering due to their advantages of convenient construction and strong adaptability. Among them, the interlocking pile support system has become the mainstream support scheme under complex geological conditions in urban core areas because it has the dual functions of soil retention and water prevention. However, under the interlocking pile support mode, the construction of side walls faces significant spatial constraints. The traditional tie-rod steel formwork support system requires the installation of tie rods through the side wall concrete, which not only damages the structural integrity and leaves the risk of water leakage, but also restricts the construction of formwork trolleys due to the narrow groove between the interlocking piles and the main structure and the space occupied by temporary facilities, making it impossible to achieve efficient formwork. At the same time, traditional formwork often uses full-span scaffolding or ordinary steel supports, which consumes a lot of materials, is inconvenient to adjust, and has high construction material and labor costs, making it difficult to adapt to the construction scenario under interlocking pile support. Therefore, the development of efficient and stable formwork technology that is suitable for narrow spaces and does not require tie rods has become an urgent need to solve this dilemma.

[0003] Meanwhile, the sidewalls of open-cut tunnels are mostly large-volume, tall cast-in-place concrete structures, subjected to significant lateral concrete pressure and vertical buoyancy during pouring. Traditional formwork systems lack effective anti-buoyancy measures and precise deformation monitoring methods. During concrete pouring, the formwork is prone to floating, displacement, and deformation, leading to sidewall elevation deviations, alignment distortions, and even safety accidents such as formwork bulging and overturning, seriously affecting construction quality and operational safety. Furthermore, traditional manual monitoring methods are inaccurate and slow to respond, failing to promptly detect and address potential formwork deformation hazards. Therefore, there is an urgent need to develop technologies that combine anti-buoyancy capabilities with real-time deformation monitoring to achieve safe and controllable sidewall construction and meet quality standards.

[0004] On the other hand, in traditional side wall construction joint waterproofing systems, the installation of components such as circumferential water inlet blind pipes and polyethylene plastic sheets often relies on manual positioning, which is cumbersome, inefficient, and difficult to guarantee installation accuracy. This can easily lead to problems such as poor joint sealing and component displacement, forming leakage channels. Summary of the Invention

[0005] The purpose of this invention is to provide a method for constructing a sidewall without tie rods for interlocking pile support in an open-cut tunnel, which solves the above-mentioned technical problems.

[0006] To solve the above-mentioned technical problems, the present invention provides a construction method for interlocking pile support of open-cut tunnel sidewalls without tie rods, comprising the following steps: Step 1: Install foundation pre-embedded bolts and end anchor bolts in the pre-set foundation pouring position, and pre-embed the circumferential water diversion blind pipe arch section and water collection tank, and then pour foundation concrete; Step 2: Install the side wall reinforcement. Pre-embed water-stop rubber strips and pre-embedded bolts on the ends of the side wall reinforcement. After the side wall reinforcement is installed, assemble the steel panel and support truss. The support truss is set at intervals on the outside of the steel panel, and a transverse distribution beam is set at the bottom of the support truss. The support truss is fixed to the anchor bolts using the transverse distribution beam. Step 3: Install the double-I-beam bases using the foundation pre-embedded bolts. Then, install the first and second diagonal braces sequentially between each double-I-beam base and the support truss. A third diagonal brace is also hinged between the foundation pre-embedded bolts and the support truss. Step 4: Install horizontal plates based on the support truss, and install electrical control regulators at intervals on the horizontal plates. Connect one end of the anti-buoyancy steel bar to the top of the side wall steel bar, and fix the other end into the locking hole of the electrical control regulator. Step 5: Install magnetic brackets on the first and second diagonal supports, and install laser rangefinders on the magnetic brackets. Keep the laser rangefinders in a horizontal position, and record and adjust the initial data of all laser rangefinders. Step 6: Pour the side wall concrete in layers and sections. After curing and demolding, install the pressure plate using the pre-embedded bolts on the side wall, and use the elastic clips at the pressure plate to install and fix the side wall section of the circumferential water diversion blind pipe and the polyethylene plastic plate.

[0007] Furthermore, in step three, the first, second, and third diagonal braces each have an adjustable helical rod for adjusting the overall length of the diagonal brace; the first, second, and third auxiliary braces are connected between the first and second diagonal braces and are distributed along the axial direction of the first and second diagonal braces; one end of the fourth auxiliary brace is fixed to the supporting truss, and the other end is fixed to the connection between the second auxiliary brace and the second diagonal brace.

[0008] Furthermore, in step three, prefabricated limiting components are installed on the foundation using pre-embedded bolts, and bottom supports are installed between the double-splitter I-beam base and the prefabricated limiting components.

[0009] Furthermore, in step one, the foundation end abuts against the interlocking pile, and a concrete surface layer is set on the inner side of the interlocking pile to serve as one side formwork of the side wall.

[0010] Furthermore, in step two, pulleys are installed at the bottom of the support truss, and template connectors are installed at the top, waist and bottom of the support truss. Water-stop steel edges are installed on both sides of the water-stop rubber strip.

[0011] Furthermore, in step three, the first, second, and third inclined braces are all equipped with strut connectors at both ends. The strut connectors at both ends of the first and second inclined braces are connected and fixed to the template connector and the strut connector at the top of the double-I-beam base, respectively. The strut connectors at both ends of the third inclined brace are connected and fixed to the template connector and the pre-embedded connector, respectively.

[0012] Furthermore, in step four, adjacent anti-buoyancy reinforcing bars are tied together by auxiliary steel wire ropes. One end of the auxiliary steel wire rope is connected to the anti-buoyancy reinforcing bar through a sleeve, and both auxiliary steel wire ropes are connected to the manual tensioner in the middle.

[0013] Furthermore, in step five, the magnetic hanger includes an upper magnetic ring and a lower magnetic ring. The upper and lower magnetic rings are connected to each other by magnetic blocks at their ends. The lower magnetic ring is connected to an adjustable connecting plate via a hinge. A connecting rod is provided on the top of the laser rangefinder. After the connecting rod passes through the mounting hole of the adjustable connecting plate, it is tightened with the thread of the connecting rod using a fixing nut to install the laser rangefinder on the bottom of the adjustable connecting plate.

[0014] Furthermore, in step six, the pressure plate is set at the same height along the side wall height direction by pre-embedded bolts on the side wall, and elastic clips are set on the pressure plate at intervals by elastic hinge shafts. The bottom of the elastic clips is coupled to the outer diameter of the side wall section of the circumferential water diversion blind pipe.

[0015] The present invention also discloses a sidewall without tie beams for interlocking pile support in open-cut tunnels, which is constructed according to the construction method of the sidewall without tie beams for interlocking pile support in open-cut tunnels.

[0016] The beneficial effects of this invention are as follows: 1) By setting up multiple sets of diagonal braces with adjustable spiral rods, efficient and stable support is achieved for the tall steel formwork on the side wall. At the same time, multiple sets of auxiliary supports are arranged between adjacent diagonal braces and bottom supports are added to the base of the diagonal braces to further improve the safety of the formwork support system. Each support can be flexibly adjusted, which solves the problem of limited construction space for the formwork trolley in some sections of the tunnel and reduces the cost of construction materials.

[0017] 2) Based on the reasonable arrangement of the template support truss, the electric control regulator is used to tie the anti-buoyancy steel bars to achieve the anti-buoyancy effect of the template during the side wall concrete pouring process. At the same time, the magnetic hanging bracket is used in conjunction with the laser rangefinder to monitor the deformation of the template, which has obvious technical benefits.

[0018] 3) By setting up a pressure plate structure with elastic clamps by pre-embedded bolts in the side wall, the circumferential water diversion blind pipe and polyethylene plastic plate at the construction joint node can be installed quickly, ensuring the waterproof performance of the side wall construction joint while improving work efficiency. Attached Figure Description

[0019] Figure 1This is a schematic diagram of the installation system of the non-pull-beam steel formwork in this invention; Figure 2 In this invention Figure 1 Detailed diagram of node A; Figure 3 In this invention Figure 1 Detailed diagram of node B; Figure 4 This is a schematic diagram of the installation of the tunnel sidewall without tie rods in this invention; Figure 5 In this invention Figure 5 Detailed diagram of node A; Figure 6 This is a schematic diagram of the installation of the anti-buoyancy system in this invention; Figure 7 This is a schematic diagram of the installation of the steel formwork deformation monitoring equipment in this invention; Figure 8 This is a schematic diagram of the waterproof structure of the tunnel sidewall in this invention; Figure 9 In this invention Figure 8 Detailed diagram of node B; Figure 10 In this invention Figure 8 AA cross-section view.

[0020] Explanation of reference numerals in the attached drawings: 1. Steel panel; 2. Support truss; 3. Second diagonal brace; 4. Template connector; 5. First diagonal brace; 6. First auxiliary brace; 7. Second auxiliary brace; 8. Third auxiliary brace; 9. Adjustable helical rod; 10. Foundation; 11. Third diagonal brace; 12. Circumferential water diversion blind pipe invert arch section; 13. Embedded connector; 14. Foundation embedded bolt; 15. Transverse distribution beam; 16. Pulley; 17. Anchor bolt; 18. Bottom support; 19. Prefabricated limiting component; 20. Support rod connector; 21. Double-layer I-beam base; 22. Interlocking pile; 23. Anti-buoyancy reinforcement; 24. Concrete surface layer; 25. Side wall reinforcement; 26. Magnetic 27. Suction-type hanger; 28. Laser rangefinder; 29. ​​Locking latch; 30. Electric control regulator; 31. Horizontal plate; 32. Manual tensioner; 33. Auxiliary steel wire rope; 34. Sleeve; 35. Upper magnetic ring; 36. Magnetic block; 37. Lower magnetic ring; 38. Hinge shaft; 39. Level; 40. Fixing nut; 41. Adjustable connecting plate; 42. Connecting rod; 43. Side wall; 44. Water-stop rubber strip; 45. Water-stop steel edge; 46. Polyethylene plastic sheet; 47. Elastic clamp; 48. Side wall section of circumferential water inlet blind pipe; 49. Pressure plate; 50. Side wall embedded bolt; 51. Elastic hinge shaft; 52. Water collection tank; 53. Fourth auxiliary support. Detailed Implementation

[0021] 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0022] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., 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, the above terms should not be construed as limiting this invention.

[0023] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0024] like Figures 1-10 The present invention provides a construction method for interlocking pile support without tie steel formwork sidewalls in open-cut tunnels, comprising the following steps: Step 1: Setting up foundation pre-embedded bolts 14 and pouring foundation 10 concrete: According to the measurement and layout position, set up foundation pre-embedded bolts 14 and end anchor bolts 17 in the preset pouring position of foundation 10, and pre-embed the circumferential water diversion blind pipe arch section 12 and water collection tank 51, and then pour foundation 10 concrete.

[0025] Step 2: Bind the side wall reinforcement 25 and install the side wall 42 steel panel 1 and supporting truss 2: Bind the side wall reinforcement 25 according to the divided construction sections, and simultaneously embed water-stop rubber strips 43 and side wall pre-embedded bolts 49 on the end side of the side wall reinforcement 25. After the side wall reinforcement 25 is bound, assemble the steel panel 1 and supporting truss 2. The supporting truss 2 is set at equal intervals on the outside of the steel panel 1, and a transverse distribution beam 15 is set at the bottom of the supporting truss 2. The supporting truss 2 is fixed to the anchor bolts 17 using the distribution beam 15.

[0026] Step 3, Installation and Debugging of Side Wall 42 Formwork Support System: Install double-span I-beam bases 21 using foundation pre-embedded bolts 14. Then, install the first diagonal brace 5 and the second diagonal brace 3 sequentially between each double-span I-beam base 21 and the support truss 2. The third diagonal brace 11 is hinged between the foundation pre-embedded bolts 14 and the support truss 2. After adjusting the position using the adjustable screw rod 9, fix it. Then, continue to install the first auxiliary support 6, the second auxiliary support 7, the third auxiliary support 8, and the fourth auxiliary support 52. After each auxiliary support is fixed, install the prefabricated limiting component 19 on the foundation 10 using foundation pre-embedded bolts 14. Then, install the bottom support 18 between the double-span I-beam bases 21 and the prefabricated limiting component 19.

[0027] Among them, the first diagonal brace 5, the second diagonal brace 3 and the third diagonal brace 11 all have adjustable screw rods 9. The two ends of the adjustable screw rods 9 are threaded to the diagonal brace rods so that rotating the adjustable screw rods 9 can adjust the overall length of the diagonal brace to match the top support distance between the diagonal brace and the supporting truss 2, and the length is fixed by the thread self-locking method.

[0028] In one embodiment of this solution, the first auxiliary support 6, the second auxiliary support 7, and the third auxiliary support 8 are connected between the first diagonal support 5 and the second diagonal support 3, and are distributed along the axial direction of the first diagonal support 5 and the second diagonal support 3. One end of the fourth auxiliary support 52 is fixed to the support truss 2, and the other end is fixed to the connection between the second auxiliary support 7 and the second diagonal support 3.

[0029] In another embodiment of this solution, the base support 18 includes a two-section structure with a threaded fit. The overall length of the base support 18 can be adjusted by screwing, thereby adapting and tightening the double-splitting I-beam base 21 on the side away from the supporting truss 2.

[0030] Step 4, Installation and Testing of Anti-buoyancy System: Install horizontal plates 30 based on the support truss 2, and install electric control regulators 29 at equal intervals on the horizontal plates 30. One end of the anti-buoyancy steel bar 23 is welded to the top of the side wall steel bar 25, and the other end is embedded in the locking hole 28 of the electric control regulator 29 for fixation. Adjacent anti-buoyancy steel bars 23 are tied together by auxiliary steel wire ropes 32.

[0031] Among them, the electronic control regulator 29 can adopt an electronically controlled winch structure.

[0032] Step 5: Installation and debugging of the multi-target distance sensing steel formwork deformation monitoring system: Install magnetic hangers 26 on the already installed first diagonal brace 5 and second diagonal brace 3, and install laser rangefinders 27 on the magnetic hangers 26 using fixing nuts 39. Adjust the angle according to the level 38 on the adjustable connecting plate 40 to keep the laser rangefinders 27 in a horizontal position, and record and debug the initial data of all laser rangefinders 27.

[0033] Step 6: Concrete pouring for side wall 42 and waterproofing treatment of construction joints: Concrete for side wall 42 is poured in layers and sections. After curing and demolding, pressure plate 48 is installed using the pre-embedded bolts 49 on the side wall. The elastic clips 46 at the pressure plate 48 are used to install and fix the side wall section 47 of the circumferential water diversion blind pipe and the polyethylene plastic plate 45.

[0034] In step one, such as Figure 4 As shown, the end of the foundation 10 abuts against the interlocking pile 22, and a concrete surface layer 24 is provided on the inner side of the interlocking pile 22 to serve as one side formwork of the side wall 42.

[0035] In step two, such as Figure 1 , Figure 2 As shown, the bottom of the support truss 2 is provided with pulleys 16, and the upper, waist and lower parts of the support truss 2 are provided with template connectors 4.

[0036] In step two, such as Figure 8 As shown, water-stopping rubber strip 43 has water-stopping steel edges 44 on both sides.

[0037] In step three, such as Figure 1 As shown, the first diagonal brace 5, the second diagonal brace 3, and the third diagonal brace 11 are all equipped with strut connectors 20 at both ends, and their lengths can be adjusted by the adjustable screw rod 9. The strut connectors 20 at both ends of the first diagonal brace 5 and the second diagonal brace 3 are respectively connected and fixed to the template connector 4 and the strut connector 20 at the top of the double-I-beam base 21. The strut connectors 20 at both ends of the third diagonal brace 11 are respectively connected and fixed to the template connector 4 and the pre-embedded connector 13. The first auxiliary support 6, the second auxiliary support 7, and the third auxiliary support 8 are all set between the first diagonal brace 5 and the second diagonal brace 3. The fourth auxiliary support 52 is set between the second diagonal brace 3 and the support truss 2.

[0038] In step three, the prefabricated limiting component 19 is set parallel to the side wall 42 along its entire length.

[0039] In step four, such as Figure 6 As shown, one end of the auxiliary wire rope 32 is connected to the anti-buoyancy steel bar 23 through the sleeve 33, and both auxiliary wire ropes 32 are connected to the manual tensioner 31 in the middle.

[0040] The manual tensioner has threaded telescopic rods at both ends. One end of the anti-buoyancy steel bar 23 is rotatably engaged with the telescopic rod, so that rotating the telescopic rod adjusts the total length of the manual tensioner, thereby controlling the tension of the anti-buoyancy steel bars 23 on both sides.

[0041] In step five, such as Figure 7 As shown, the magnetic hanging bracket 26 includes an upper magnetic ring 34 and a lower magnetic ring 36. The upper magnetic ring 34 and the lower magnetic ring 36 are connected to each other by magnetic blocks 35 at their ends. The lower magnetic ring 36 is connected to an adjustable connecting plate 40 by a hinge 37.

[0042] Among them, the hinge 37 adopts a damped rotating shaft to ensure that the position can be in the current horizontal state after the rotation angle. The upper magnetic ring 34 and the lower magnetic ring 36 are both set in a semi-circular structure so that after they are magnetically fixed, they are wrapped in a ring at the diagonal brace.

[0043] In step five, a connecting rod 41 is provided on the top of the laser rangefinder 27. After the connecting rod 41 passes through the mounting hole of the adjustable connecting plate 40, the fixing nut 39 is tightened with the connecting rod 41 to install the laser rangefinder 27 on the bottom of the adjustable connecting plate 40.

[0044] In step six, such as Figure 9 , Figure 10 As shown, the pressure plate 48 is set at the same height along the side wall 42 by the side wall pre-embedded bolts 49. The pressure plate 48 is provided with elastic clips 46 at equal intervals by the elastic hinge shafts 50. The bottom of the elastic clips 46 is coupled to the outer diameter of the side wall section 47 of the circumferential water diversion blind pipe.

[0045] This invention is not limited to the preferred embodiments described above. Anyone can derive other products in various forms under the guidance of this invention. However, regardless of any changes in shape or structure, any technical solution that is the same as or similar to this application falls within the protection scope of this invention.

Claims

1. A construction method for interlocking pile support without tie rod steel formwork sidewalls in open-cut tunnels, characterized in that, Includes the following steps: Step 1: Set the foundation pre-embedded bolts (14) and end side anchor bolts (17) in the pre-set pouring position of the foundation (10), and pre-embed the circumferential water diversion blind pipe arch section (12) and water collection tank (51), and then pour the foundation (10) concrete. Step 2: Install the side wall reinforcement (25), pre-embed water-stop rubber strip (43) and side wall pre-embedded bolts (49) on the end side of the side wall reinforcement (25), and after the side wall reinforcement (25) is installed, assemble the steel panel (1) and the support truss (2). The support truss (2) is spaced out on the outside of the steel panel (1), and a transverse distribution beam (15) is set at the bottom of the support truss (2). The support truss (2) is fixed to the anchor bolts (17) using the transverse distribution beam (15). Step 3: Install the double-I-beam base (21) through the foundation pre-embedded bolts (14), and then install the first diagonal brace (5) and the second diagonal brace (3) in sequence between each double-I-beam base (21) and the support truss (2). A third diagonal brace (11) is hinged between the foundation pre-embedded bolts (14) and the support truss (2). Step 4: Install the horizontal plate (30) based on the support truss (2), and install the electric control regulator (29) at intervals on the horizontal plate (30). One end of the anti-buoyancy steel bar (23) is connected to the top of the side wall steel bar (25), and the other end is embedded in the locking hole (28) of the electric control regulator (29) for fixation. Step 5: Install magnetic hangers (26) on the first diagonal brace (5) and the second diagonal brace (3), and install laser rangefinders (27) on the magnetic hangers (26), keep the laser rangefinders (27) in a horizontal position, and record and debug the initial data of all laser rangefinders (27); Step 6: Pour the side wall (42) concrete in layers and sections. After curing and demolding, install the pressure plate (48) using the pre-embedded bolts (49) of the side wall, and use the elastic clips (46) at the pressure plate (48) to install and fix the circumferential water diversion blind pipe side wall section (47) and polyethylene plastic plate (45).

2. The construction method for interlocking pile support without tie-beam steel formwork sidewalls in open-cut tunnels according to claim 1, characterized in that: In step three, the first diagonal brace (5), the second diagonal brace (3) and the third diagonal brace (11) all have adjustable screw rods (9) to adjust the overall length of the diagonal brace; the first auxiliary brace (6), the second auxiliary brace (7) and the third auxiliary brace (8) are connected between the first diagonal brace (5) and the second diagonal brace (3) and are distributed along the axial direction of the first diagonal brace (5) and the second diagonal brace (3); one end of the fourth auxiliary brace (52) is fixed at the support truss (2) and the other end is fixed at the connection between the second auxiliary brace (7) and the second diagonal brace (3).

3. The construction method for interlocking pile support without tie steel formwork sidewalls in open-cut tunnels according to claim 1, characterized in that: In step three, the prefabricated limiting component (19) is installed on the foundation (10) by pre-embedded bolts (14), and the bottom support (18) is installed between the double-splitting I-beam base (21) and the prefabricated limiting component (19).

4. The construction method for interlocking pile support without tie steel formwork sidewalls in open-cut tunnels according to claim 1, characterized in that: In step one, the end of the foundation (10) abuts against the interlocking pile (22), and a concrete surface layer (24) is set on the inner side of the interlocking pile (22) to serve as one side formwork of the side wall (42).

5. The construction method for interlocking pile support without tie steel formwork sidewalls in open-cut tunnels according to claim 1, characterized in that: In step two, pulleys (16) are provided at the bottom of the support truss (2), template connectors (4) are provided at the upper, waist and lower parts of the support truss (2), and water-stop steel edges (44) are provided on both sides of the water-stop rubber strip (43).

6. The construction method for interlocking pile support without tie-beam steel formwork sidewalls in open-cut tunnels according to claim 5, characterized in that: In step three, the first diagonal brace (5), the second diagonal brace (3) and the third diagonal brace (11) are all provided with strut connectors (20) at both ends. The strut connectors (20) at both ends of the first diagonal brace (5) and the second diagonal brace (3) are respectively connected and fixed to the template connector (4) and the strut connector (20) at the top of the double-jointed I-beam base (21). The strut connectors (20) at both ends of the third diagonal brace (11) are respectively connected and fixed to the template connector (4) and the pre-embedded connector (13).

7. The construction method for interlocking pile support without tie steel formwork sidewalls in open-cut tunnels according to claim 1, characterized in that: In step four, adjacent anti-buoyancy reinforcing bars (23) are tied together by auxiliary steel wire ropes (32). One end of the auxiliary steel wire rope (32) is connected to the anti-buoyancy reinforcing bar (23) through a sleeve (33), and both auxiliary steel wire ropes (32) are connected to the manual tensioner (31) in the middle.

8. The construction method for interlocking pile support without tie steel formwork sidewalls in open-cut tunnels according to claim 1, characterized in that: In step five, the magnetic hanger (26) includes an upper magnetic ring (34) and a lower magnetic ring (36). The upper magnetic ring (34) and the lower magnetic ring (36) are connected to each other by magnetic blocks (35) at their ends. The lower magnetic ring (36) is connected to an adjustable connecting plate (40) through a hinge (37). The top of the laser rangefinder (27) is provided with a connecting rod (41). After the connecting rod (41) passes through the mounting hole of the adjustable connecting plate (40), the connecting rod (41) is tightened with the thread of the connecting rod (41) using a fixing nut (39) to install the laser rangefinder (27) on the bottom of the adjustable connecting plate (40).

9. The construction method for interlocking pile support without tie steel formwork sidewalls in open-cut tunnels according to claim 1, characterized in that: In step six, the pressure plate (48) is set at the same height along the side wall (42) by the pre-embedded bolts (49) on the side wall. Elastic clips (46) are set at intervals on the pressure plate (48) by the elastic hinge shaft (50). The bottom of the elastic clips (46) is coupled to the outer diameter of the side wall section (47) of the circumferential water diversion blind pipe.

10. A type of open-cut tunnel with interlocking pile support for a sidewall without tie rods and steel formwork, characterized in that: The method described in any one of claims 1-9 for constructing a sidewall without tie rods for interlocking pile support in an open-cut tunnel is as follows.

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