Construction method for protecting existing building wall during tunnel excavation

Abstract

The invention relates to a construction method for protecting an existing building wall during tunnel excavation, and relates to the technical field of existing building supporting, and the construction method comprises the following construction steps that reinforcing piles are arranged for the periphery of a starting well needing to be excavated; an isolation assembly capable of isolating the peripheral side wall of the starting well from the foundation is arranged between the reinforcing pile and the starting well; a supporting assembly is arranged on one side wall, symmetrical to a tunnel excavation opening, in the starting well, and the supporting assembly supports the wall body through the counter-force effect; reinforcing the ground in the starting well to form a ground reinforcing layer; and the reinforcing assembly is driven underground, and the reinforcing assembly is used for improving the stability of the ground in the starting well. The method has the effect of conveniently protecting the existing building according to the foundation settlement condition.

Description

Technical Field

[0001] The present application relates to the technical field of existing building support, and in particular to a construction method for protecting existing building walls through tunnel excavation. Background Art

[0002] Shield tunnel construction technology has been widely used in the domestic subway market, municipal water supply tunnels, power tunnels and other fields. An extremely important item in its construction quality control is to control the deviation value between the tunnel axis and the design axis. Therefore, the attitude control of the shield machine is the key in the entire shield tunnel construction process, and the attitude control of the shield machine is particularly important during the initial exit stage of the shield machine.

[0003] However, the starting shaft is close to buildings, and it is easy to need to reinforce the rear wall of the starting shaft during excavation. The current reinforcement method for nearby buildings is to set reinforcing steel plates and concrete pouring reinforcement walls around the starting shaft, so that the existing buildings can be reinforced during tunnel excavation, thereby protecting the existing building walls.

[0004] However, over time, the foundation may settle, and reinforced steel plates and walls may find it difficult to support and protect adjacent buildings. Summary of the invention

[0005] In order to facilitate the protection of existing buildings according to the foundation settlement conditions, the present application provides a construction method for protecting the walls of existing buildings by tunnel excavation.

[0006] The present application provides a construction method for tunnel excavation to protect existing building walls, which adopts the following technical solutions: A construction method for protecting existing building walls during tunnel excavation, the construction steps are as follows: reinforcement piles are set around a starting shaft to be excavated; an isolation component capable of isolating the surrounding side wall of the starting shaft from a foundation is set between the reinforcement piles and the starting shaft; a support component is set at a side wall symmetrical to a tunnel excavation opening in the starting shaft, the support component supports the wall by a reaction force; the ground in the starting shaft is reinforced to form a ground reinforcement layer; and the reinforcement component is driven into the ground, the reinforcement component is used to improve the stability of the ground in the starting shaft.

[0007] By adopting the above technical scheme, the foundation and the starting well are isolated by setting up an isolation component, and the foundation on the side where the existing building is located is supported by the support component. At the same time, the ground in the starting well is reinforced, and the reinforcement component is driven into the ground reinforcement layer to further enhance the stability between the ground reinforcement layer and the foundation. When the foundation settles, the support component can be used to continuously support the wall, so that the support component maintains the supporting force on one side of the existing building, thereby facilitating the protection of the existing building according to the foundation settlement condition.

[0008] Optionally, the isolation assembly includes an isolation belt, an isolation support plate and an isolation wall, the isolation belt is used to isolate and protect the surrounding sides of the starting shaft away from the tunnel excavation opening, the isolation support plate is arranged at the starting shaft near the tunnel excavation opening, two isolation support plates are symmetrically arranged, one end of the isolation support plate is abutted against the isolation belt near the tunnel excavation opening, and the other end is obliquely arranged at the starting shaft near the tunnel excavation opening, the isolation wall is arranged at one side wall of the starting shaft, and the isolation wall is symmetrically arranged to the tunnel excavation opening.

[0009] By adopting the above technical solution, the isolation belt, isolation support plate and isolation wall can isolate the foundation from the starting well, thereby reducing the impact of foundation settlement on the starting well and existing buildings.

[0010] Optionally, the support assembly includes a support plate and a support diagonal brace, the support plate is arranged on one side of the isolation wall and fits with the isolation wall, one end of the support diagonal brace is rotatably connected to the support plate, and the other end is connected to the ground reinforcement layer, a connecting piece is provided between the support diagonal brace and the support plate, one end of the connecting piece is rotatably connected to the support diagonal brace, and the other end is slidably connected to the support plate, and the sliding direction is vertical sliding, and a fixing piece is provided at the connecting piece, and the fixing piece is used to fix the connecting piece on the support plate.

[0011] By adopting the above technical solution, when the foundation settles, the connection between the fixing piece and the supporting plate is released, and the end of the connecting piece close to the supporting plate is pressed down until the supporting diagonal brace again tightly abuts the supporting plate against the side wall of the isolation wall, and then the fixing piece and the supporting plate are fixed to complete the adjustment of the supporting diagonal brace, thereby improving the support of the supporting assembly to the foundation when the foundation settles and protecting the existing building.

[0012] Optionally, the fixing device includes a sliding block slidably connected to the support plate and a counterweight block arranged above the sliding block, a sliding groove is opened on the support plate, the counterweight block is located in the sliding groove and can slide along the sliding groove, a locking screw is arranged on the counterweight block, the locking screw passes through the counterweight block, the support plate, and the isolation wall and is inserted into the foundation, and the tightening screw is threadedly connected to the counterweight block, the support plate, and the isolation wall.

[0013] By adopting the above technical solution, when adjusting the fit between the support plate and the isolation wall, the connection between the locking screw and the counterweight block, the support plate and the isolation wall is released, and the counterweight block is pressed down until the supporting diagonal brace presses the support plate against the isolation wall again, and the locking screw is installed into the foundation again to complete the fixation of the counterweight block, so that the counterweight block fixes the sliding block, and the support plate is tightly pressed against one side of the isolation wall, thereby improving the support for the foundation of the existing building.

[0014] Optionally, there are multiple connecting members, including a first connecting seat and a second connecting seat, the first connecting seat is connected to one end of the supporting brace close to the supporting plate, the second connecting seat is connected to the sliding block, the second connecting seat is rotatably connected to the first connecting seat, and multiple elastic members are also provided between the supporting brace and the sliding block, and the two ends of the elastic members are respectively connected to the supporting brace and the sliding block.

[0015] By adopting the above technical solution, the connecting member and the elastic member enable the supporting diagonal brace to continuously connect and support the sliding block when the sliding block is pressed down.

[0016] Optionally, a reinforcement assembly is provided under the ground reinforcement layer, and the reinforcement assembly includes a plurality of reinforcement rods, which are evenly distributed under the ground reinforcement layer and connected to the ground reinforcement layer at the top, a plurality of reinforcement rings are provided at intervals along the height direction of the reinforcement rods, and a plurality of reinforcement plates are provided circumferentially on the reinforcement rods.

[0017] By adopting the above technical solution, the reinforcement rods, reinforcement rings and reinforcement plates can improve the connectivity between the ground reinforcement layer and the foundation, thereby improving the stability of the ground reinforcement layer in the starting well, and further improving the stability of the support assembly in the starting well.

[0018] Optionally, an adjustment component is provided between the ground reinforcement layer and the supporting diagonal brace, the adjustment component comprising a mounting plate, a first clamping tooth, an adjustment gear and an adjustment rack, the mounting plate is located on the top surface of the ground reinforcement layer, a plurality of first clamping teeth are provided, and the plurality of first clamping teeth are arranged in sequence at intervals at the bottom of the mounting plate from the supporting diagonal brace close to the supporting plate, a plurality of second clamping teeth are provided on a side of the ground reinforcement layer close to the mounting plate, the first clamping teeth and the second clamping teeth can be engaged with each other, the adjustment gear is rotatably connected to the side wall of the mounting plate away from the supporting plate and the tunnel excavation opening, the adjustment rack is connected to the ground reinforcement layer, the adjustment gear is meshed with the adjustment rack, a plurality of locking members are provided on the mounting plate, and the locking members are used to fix the mounting plate and the ground reinforcement layer.

[0019] By adopting the above technical solution, when adjusting the support angle between the supporting diagonal brace and the ground, the adjusting gear can be rotated so that the adjusting gear is close to the supporting plate on the adjusting rack, and the first clamping tooth moves toward the second clamping tooth close to the supporting plate until the first clamping tooth is engaged in the second clamping tooth closer to the supporting plate, thereby further increasing the supporting force of the supporting diagonal brace on the supporting plate, and fitting the supporting plate more closely to the isolation wall. After the adjustment is completed, the locking piece is used to fix the mounting plate and the ground reinforcement layer, so as to facilitate the adjustment of the supporting property of the supporting assembly on the foundation, thereby facilitating the protection of the existing building according to the foundation settlement conditions.

[0020] Optionally, the locking piece is detachably connected to the reinforcement rod.

[0021] By adopting the above technical solution, it is convenient to adjust the position of the support assembly while improving the stability of the locking member.

[0022] In summary, the present application includes at least one of the following beneficial technical effects: 1. By setting an isolation component at the starting well, the isolation component reinforces the foundation, and the support component supports the side wall of the starting well close to the existing building, and reinforces the ground of the starting well. At the same time, the support component can adjust the support angle according to the settlement of the foundation, so as to protect the existing building according to the settlement of the foundation; 2. By setting a support plate, a slidable sliding block is set on the support plate, and the sliding block can be fixed by a counterweight block and a locking screw. When the foundation settles and there is a gap between the support plate and the isolation wall, the position of the sliding block on the support plate is adjusted so that the supporting diagonal brace can press the support plate again and make the support plate close to the isolation wall, thereby protecting the existing building according to the foundation settlement conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present application; Figure 2 is a schematic structural diagram of another perspective of hiding the first reinforcement plate and the second reinforcement plate in an embodiment of the present application; Figure 3 is a schematic structural diagram of a support assembly according to an embodiment of the present application; Figure 4 is a partial structural schematic diagram of a support assembly according to an embodiment of the present application; Figure 5 is a partial three-dimensional cross-sectional view of an embodiment of the present application; Figure 6 is a partial cross-sectional view of a reinforcement assembly according to an embodiment of the present application; Figure 7 is a three-dimensional cross-sectional view from another perspective of an embodiment of the present application; Figure 8 yes Figure 3 Enlarged schematic diagram of part A.

[0025] Explanation of the reference numerals: 1. Starting shaft; 11. Reinforcement pile; 12. Ground reinforcement layer; 121. Second latch; 13. Tunnel excavation opening; 2. Isolation assembly; 21. Isolation belt; 22. Isolation support plate; 23. Isolation wall; 3. Support assembly; 31. Support plate; 311. Sliding groove; 32. Support diagonal brace; 33. Connecting piece; 331. First connecting seat; 332. Second connecting seat; 333. Elastic piece; 34. Fixing piece; 341. Sliding block; 342. Counterweight block; 343. Locking screw; 35. First reinforcement plate; 36. Second reinforcement plate; 4. Reinforcement assembly; 41. Reinforcement rod; 42. Reinforcement ring; 43. Reinforcement sheet; 5. Adjustment assembly; 51. Mounting plate; 52. First latch; 53. Adjustment gear; 54. Adjustment rack; 55. Locking piece. DETAILED DESCRIPTION

[0026] The following is combined with Figure 1-8 This application is described in further detail.

[0027] The embodiment of the present application discloses a construction method for protecting an existing building wall by tunnel excavation.

[0028] Reference Figure 1 , Figure 2 and Figure 3 A construction method for protecting existing building walls by tunnel excavation, the construction steps are as follows: reinforcement piles 11 are set around the starting shaft 1 to be excavated; the reinforcement piles 11 are driven in by high-pressure jet grouting. An isolation component 2 is set between the reinforcement piles 11 and the starting shaft 1 to isolate the surrounding side wall of the starting shaft 1 from the foundation. A support assembly 3 is arranged at a side wall symmetrical to the tunnel excavation opening 13 in the starting shaft 1. The support assembly 3 supports the wall by means of reaction force. The support assembly 3 can also adjust its position in the starting shaft 1. When the foundation settles, the support assembly 3 continuously supports the side wall of the starting shaft 1 tightly, thereby improving the support of the support assembly 3 to the foundation. At the same time, before the support assembly 3 is arranged, the ground in the starting shaft 1 is reinforced to form a ground reinforcement layer 12, which is a concrete layer. The reinforcement assembly 4 is driven into the ground. The reinforcement assembly 4 is used to improve the stability of the ground in the starting shaft 1. In this embodiment, the reinforcement assembly 4 is connected to the ground reinforcement layer 12.

[0029] Reference Figure 2The isolation assembly 2 includes an isolation belt 21, an isolation support plate 22 and an isolation wall 23. The isolation belt 21 is used to isolate and protect the surrounding side of the starting shaft 1 away from the tunnel excavation opening 13. The isolation belt 21 is in a "C" shape as a whole. The opening of the isolation belt 21 faces the tunnel excavation opening 13. The isolation belt 21 is a concrete casting belt layer. The isolation support plate 22 is arranged near the tunnel excavation opening 13 of the starting shaft 1. Two isolation support plates 22 are symmetrically arranged. One end of the isolation support plate 22 abuts against the isolation belt 21 near the tunnel excavation opening 13, and the other end is inclinedly arranged at the starting shaft 1 near the tunnel excavation opening 13. In this embodiment, the end of the support plate 31 away from the isolation belt 21 is inclined inward. The isolation wall 23 is arranged at one side wall of the starting shaft 1. The isolation wall 23 is symmetrically arranged to the tunnel excavation opening 13. The isolation wall 23 is a concrete casting wall.

[0030] Reference Figure 3 A reinforcement assembly 4 is provided below the ground reinforcement layer 12. The reinforcement assembly 4 includes a plurality of reinforcement rods 41. The plurality of reinforcement rods 41 are evenly distributed below the ground reinforcement layer 12 and the top ends are connected to the ground reinforcement layer 12. The reinforcement rods 41 are provided with six reinforcement rings 42 at intervals along their height direction. Four reinforcement plates 43 are provided circumferentially on the reinforcement rods 41. The reinforcement rods 41, reinforcement rings 42 and reinforcement plates 43 are all formed by casting concrete.

[0031] Reference Figure 3 and Figure 4 The support assembly 3 includes a support plate 31 and a support diagonal brace 32. The support plate 31 is arranged on one side of the isolation wall 23 and is in contact with the isolation wall 23. The support plate 31 is a steel plate, and the support diagonal brace 32 is a rectangular steel brace. One end of the support diagonal brace 32 is rotatably connected to the support plate 31, and the other end is connected to the ground reinforcement layer 12, so that the support diagonal brace 32 is arranged in an inclined state between the ground reinforcement layer 12 and the support plate 31; a connecting piece 33 is provided between the support diagonal brace 32 and the support plate 31, one end of the connecting piece 33 is rotatably connected to the support diagonal brace 32, and the other end is slidably connected to the support plate 31, and the sliding direction of the end of the connecting piece 33 close to the support plate 31 is vertical sliding.

[0032] Reference Figure 4 , Figure 5 and Figure 6In order to facilitate the connection of the connecting member 33 to the supporting plate 31 and to adjust the sliding position of the connecting member 33 , a fixing member 34 is provided at the connecting member 33 , and the fixing member 34 is used to fix the connecting member 33 to the supporting plate 31 . The fixing member 34 includes a sliding block 341 vertically slidably connected to the support plate 31 and a counterweight block 342 arranged above the sliding block 341. The sliding block 341 is a "T"-shaped block. A sliding groove 311 is opened on the support plate 31. The sliding groove 311 is a "T"-shaped groove. The counterweight block 342 is located in the sliding groove 311 and can slide along the sliding groove 311. The counterweight block 342 is two "T"-shaped blocks connected by a connecting plate. The counterweight block 342 is a solid steel block as a whole. A locking screw 343 is arranged on the counterweight block 342. The locking screw 343 passes through the counterweight block 342, the support plate 31, and the isolation wall 23 and is threadedly connected to the counterweight block 342, the support plate 31, and the isolation wall 23 and is inserted into the foundation.

[0033] Reference Figure 4 , there are multiple connecting members 33 and they are distributed in the upper and lower parts of the sliding block 341. The connecting member 33 includes a first connecting seat 331 and a second connecting seat 332. The first connecting seat 331 is welded to the end of the supporting diagonal brace 32 close to the supporting plate 31, and the second connecting seat 332 is welded to the sliding block 341. The second connecting seat 332 is rotatably connected to the first connecting seat 331 through a rotating shaft. A plurality of elastic members 333 are also provided between the supporting diagonal brace 32 and the sliding block 341. The two ends of the elastic member 333 are respectively welded to the supporting diagonal brace 32 and the sliding block 341. The elastic member 333 is a spring. In this embodiment, the elastic member 333 is located between the connecting members 33.

[0034] Reference Figure 6 , Figure 7 In order to improve the supporting effect, a first reinforcing plate 35 and a second reinforcing plate 36 are further provided between the supporting plate 31 and the foundation surface. The first reinforcing plate 35 and the second reinforcing plate 36 are vertically arranged and the two ends close to each other are rotatably connected by a rotating shaft. The first reinforcing plate 35 is fixed to the supporting plate 31 by bolts, and the second reinforcing plate 36 is fixed to the foundation by screws. The first reinforcing plate 35 and the second reinforcing plate 36 reinforce the foundation close to the supporting plate 31 again.

[0035] Reference Figure 6 , Figure 7 and Figure 8, an adjustment component 5 is provided between the ground reinforcement layer 12 and the supporting diagonal brace 32, the adjustment component 5 includes a mounting plate 51, a first clamping tooth 52, an adjustment gear 53 and an adjustment rack 54, the mounting plate 51 is located on the top surface of the ground reinforcement layer 12, the mounting plate 51 is a steel plate, a plurality of first clamping teeth 52 are provided, and a plurality of first clamping teeth 52 are sequentially arranged at intervals on the bottom of the mounting plate 51 in the direction from the supporting diagonal brace 32 close to the supporting plate 31, that is, a plurality of first clamping teeth 52 are arranged at intervals from left to right on the bottom surface of the mounting plate 51, and a plurality of first clamping teeth 52 are integrally formed with the mounting plate 51, and a plurality of second clamping teeth 121 are provided on a side of the ground reinforcement layer 12 close to the mounting plate 51, the first clamping teeth 52 and the second clamping teeth 121 can be clamped and engaged, and the first clamping teeth 52 and the second clamping teeth 121 are both right-angle racks, and in order to facilitate the first clamping teeth 52 to move forward and engage with the second clamping teeth 121, a corner of the first clamping teeth 52 close to the second clamping teeth 121 is arranged in an arc shape.

[0036] Reference Figure 6 , Figure 7 and Figure 8 The adjusting gear 53 is rotatably connected to the side wall of the mounting plate 51 away from the supporting plate 31 and the tunnel excavation opening 13 through a rotating shaft, the adjusting rack 54 is welded to the ground reinforcement layer 12, the adjusting gear 53 is meshed with the adjusting rack 54, and a plurality of locking members 55 are provided on the mounting plate 51, and the locking members 55 are used to fix the mounting plate 51 and the ground reinforcement layer 12. The locking members 55 are detachably connected to the reinforcement rod 41, and the locking members 55 can be bolts or screws. In this embodiment, the locking members 55 are hexagon socket bolts.

[0037] The implementation principle of a construction method for tunnel excavation to protect the walls of existing buildings in an embodiment of the present application is as follows: when protecting the existing buildings, reinforcing piles 11 are driven into the starting well 1 before excavating the starting well 1, so that the reinforcing piles 11 reinforce the sides of the starting well 1 and then the starting well 1 is excavated. When excavating the starting well 1, an isolation wall 23 and a supporting isolation support plate 22 are excavated and cast, and the starting well 1 is reinforced again. After the excavation of the starting well 1 is completed, the ground reinforcement layer 12 is constructed and the support assembly 3 and the reinforcement assembly 4 are installed. While reinforcing the ground reinforcement layer 12, the side of the starting well 1 close to the existing building is supported, and the support assembly 3 can be adjusted by the adjustment assembly 5, and can still support the isolation wall 23 tightly when the foundation settles and a gap is generated between the isolation wall 23 and the support plate 31, so as to protect the existing building according to the foundation settlement conditions.

[0038] Unless otherwise defined, the technical terms or scientific terms used in this application should be understood by people with ordinary skills in the field to which this application belongs. The words "first", "second", "third" and similar words used in the specification and claims of this application do not indicate any order, quantity or importance, but are only used to distinguish different components. "One" or "one" and similar words do not indicate a quantitative limit, but indicate that there is at least one. "Include" or "comprise" and similar words mean that the elements or objects appearing before "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0039] The above are all optional embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A construction method for tunnel excavation to protect existing building walls, characterized in that: The construction steps are as follows: Reinforcement piles (11) are arranged around the starting well (1) to be excavated; An isolation component (2) capable of isolating the peripheral wall of the starting well (1) from the foundation is provided between the reinforcement pile (11) and the starting well (1); A support assembly (3) is provided at a side wall symmetrical to the tunnel excavation opening (13) in the starting shaft (1), and the support assembly (3) supports the wall by utilizing reaction force; Reinforcing the ground inside the launch well (1) to form a ground reinforcement layer (12); A reinforcement component (4) is driven into the ground, and the reinforcement component (4) is used to improve the stability of the ground in the starting well (1).

2. A construction method for tunnel excavation to protect existing building walls according to claim 1, characterized in that: The isolation assembly (2) comprises an isolation belt (21), an isolation support plate (22) and an isolation wall (23); the isolation belt (21) is used to isolate and protect the surrounding side of the starting shaft (1) away from the tunnel excavation opening (13); the isolation support plate (22) is arranged at the starting shaft (1) near the tunnel excavation opening (13); two isolation support plates (22) are symmetrically arranged; one end of the isolation support plate (22) abuts against the isolation belt (21) near the tunnel excavation opening (13); the other end is inclinedly arranged at the starting shaft (1) near the tunnel excavation opening (13); the isolation wall (23) is arranged at a side wall of the starting shaft (1); and the isolation wall (23) is symmetrically arranged with respect to the tunnel excavation opening (13).

3. A construction method for tunnel excavation to protect existing building walls according to claim 2, characterized in that: The support assembly (3) comprises a support plate (31) and a support diagonal brace (32); the support plate (31) is arranged on one side of the isolation wall (23) and is in contact with the isolation wall (23); one end of the support diagonal brace (32) is rotatably connected to the support plate (31), and the other end is connected to the ground reinforcement layer (12); a connecting piece (33) is provided between the support diagonal brace (32) and the support plate (31); one end of the connecting piece (33) is rotatably connected to the support diagonal brace (32), and the other end is slidably connected to the support plate (31), and the sliding direction is vertical sliding; a fixing piece (34) is provided at the connecting piece (33), and the fixing piece (34) is used to fix the connecting piece (33) on the support plate (31).

4. A construction method for tunnel excavation to protect existing building walls according to claim 3, characterized in that: The fixing member (34) comprises a sliding block (341) slidably connected to the supporting plate (31) and a counterweight block (342) arranged above the sliding block (341); a sliding groove (311) is provided on the supporting plate (31); the counterweight block (342) is located in the sliding groove (311) and can slide along the sliding groove (311); a locking screw (343) is provided on the counterweight block (342); the locking screw (343) penetrates the counterweight block (342), the supporting plate (31) and the isolation wall (23) and is inserted into the foundation; the tightening screw is threadedly connected to the counterweight block (342), the supporting plate (31) and the isolation wall (23).

5. A construction method for tunnel excavation to protect existing building walls according to claim 3, characterized in that: The connecting members (33) are provided in plurality, and the connecting members (33) include a first connecting seat (331) and a second connecting seat (332), the first connecting seat (331) being connected to one end of the supporting diagonal brace (32) close to the supporting plate (31), the second connecting seat (332) being connected to the sliding block (341), the second connecting seat (332) being rotatably connected to the first connecting seat (331), and a plurality of elastic members (333) being provided between the supporting diagonal brace (32) and the sliding block (341), the two ends of the elastic members (333) being respectively connected to the supporting diagonal brace (32) and the sliding block (341).

6. A construction method for tunnel excavation to protect existing building walls according to claim 1, characterized in that: A reinforcement assembly (4) is provided below the ground reinforcement layer (12), the reinforcement assembly (4) comprising a plurality of reinforcement rods (41), the plurality of reinforcement rods (41) being evenly distributed below the ground reinforcement layer (12) and having their top ends connected to the ground reinforcement layer (12), a plurality of reinforcement rings (42) being provided at intervals along the height direction of the reinforcement rods (41), and a plurality of reinforcement sheets (43) being provided circumferentially on the reinforcement rods (41).

7. A construction method for tunnel excavation to protect existing building walls according to claim 1, characterized in that: An adjustment component (5) is provided between the ground reinforcement layer (12) and the supporting diagonal brace (32), the adjustment component (5) comprising a mounting plate (51), a first latching tooth (52), an adjustment gear (53) and an adjustment rack (54), the mounting plate (51) being located on the top surface of the ground reinforcement layer (12), a plurality of first latching teeth (52) being provided, the plurality of first latching teeth (52) being arranged at intervals in sequence at the bottom of the mounting plate (51) from the supporting diagonal brace (32) close to the supporting plate (31), and a first latching tooth (53) being provided at the bottom of the mounting plate (51) from the supporting diagonal brace (32) close to the supporting plate (31). A plurality of second latching teeth (121) are provided on the surface, the first latching teeth (52) and the second latching teeth (121) can be latched and engaged, the adjusting gear (53) is rotatably connected to the side wall of the mounting plate (51) away from the supporting plate (31) and the tunnel excavation opening (13), the adjusting rack (54) is connected to the ground reinforcement layer (12), the adjusting gear (53) and the adjusting rack (54) are meshed, and the mounting plate (51) is provided with a plurality of locking members (55), the locking members (55) are used to fix the mounting plate (51) and the ground reinforcement layer (12).

8. A construction method for tunnel excavation to protect existing building walls according to claim 7, characterized in that: The locking piece (55) is detachably connected to the reinforcement rod (41).

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