Waste box culvert transverse area groove wall reinforced underground diaphragm wall and construction method

Abstract

The invention provides a construction method for reinforcing an underground diaphragm wall through a groove wall in a waste box culvert transverse area. The construction method comprises a construction preparation stage, a waste box culvert dismantling stage, a groove wall reinforcing stage, an underground diaphragm wall construction stage and a construction monitoring and acceptance inspection stage. During pile position lofting and drilling in the groove wall reinforcing stage, the precise marking and drill bit hole aligning technology is adopted; during guide wall construction and guide wall supporting in the underground diaphragm wall construction stage, a local pre-guide wall rapid sealing technology and a deep guide wall profile steel supporting technology are adopted respectively, and during reinforcement cage manufacturing and hoisting, an L-shaped reinforcement cage detachable diagonal bracing technology is adopted. The waste box culvert dismantling procedure is reasonably arranged, and the construction period is shortened; the construction accuracy of the groove wall reinforcing pile can be guaranteed through the precise marking and drill bit hole aligning technology, and additional deviation correction work caused by pile center deviation overrun is prevented; by means of the local prefabrication guide wall rapid sealing technology and the deep guide wall profile steel supporting technology, the construction efficiency is improved, and the construction quality is also improved.

Description

Technical Field

[0001] The invention relates to the technical field of underground continuous wall construction, in particular to an underground continuous wall reinforced with a trench wall in an abandoned box culvert crossing area and a construction method. Background Art

[0002] As a deep foundation support structure, underground continuous wall is widely used in urban subways, deep foundation pits and other fields due to its advantages such as high overall stiffness, good anti-seepage performance and low construction vibration. However, in areas with complex geological conditions or those affected by existing underground structures, especially when the construction area crosses abandoned box culverts, traditional underground continuous wall construction methods face severe challenges.

[0003] Abandoned box culverts are mostly formed by the remains of old municipal facilities. There is usually residual silt and water inside the box culvert. The box body is usually damaged due to long-term erosion by groundwater, forming local voids or weak interlayers. When trenching in such areas, the trench wall is very likely to collapse due to soil disturbance, and the mud wall protection effect is significantly reduced, and even causes problems such as mud leakage and trench section deviation. In addition, the interface stability between the abandoned box culvert and the surrounding soil is poor. It is difficult to effectively close the seepage channel between the box culvert and the soil by directly using trench wall reinforcement technology (such as cement soil mixing piles and high-pressure rotary jet piles), resulting in a sharp increase in the risk of trench wall instability during the trenching process, seriously affecting the wall quality and construction safety.

[0004] In the prior art, the methods for dealing with underground continuous walls crossing existing obstacles mainly include local excavation and removal, grouting reinforcement, or adjusting the trench segment division. However, when the abandoned box culverts are buried deep and distributed over a wide range, the cost of complete removal is high and may cause settlement of the surrounding strata; and the traditional grouting reinforcement process has problems such as poor controllability of slurry diffusion and weak adhesion to the box culvert structure, and it is impossible to form a continuous and reliable reinforcement system. Therefore, there is an urgent need for a special trench wall reinforcement method for abandoned box culvert crossing areas. By optimizing process parameters and strengthening structural connections, the stability of the underground continuous wall trench and the integrity of the wall can be ensured, while reducing construction risks and costs. Summary of the invention

[0005] The object of the present invention is to provide an underground continuous wall and a construction method for reinforcing the trench wall in the abandoned box culvert crossing area to solve the above-mentioned technical problems.

[0006] In order to solve the above technical problems, the present invention provides a construction method for reinforcing an underground continuous wall of a trench wall in an abandoned box culvert crossing area, comprising the following steps:

[0007] S1: Dismantling of abandoned box culverts: dismantling the top plate of the box culvert at the location of the ground-connected wall; pumping out water and clearing silt; dismantling the top plate of the box culvert in the foundation pit between the ground-connected walls; dismantling the bottom plate of the vertical wall of the box culvert at the location of the ground-connected wall; backfilling the soil in layers;

[0008] S2: Trench wall reinforcement stage: pile position setting; drilling; high-pressure rotary jet grouting; pile formation and maintenance;

[0009] S3: Underground continuous wall construction phase: guide wall construction; guide wall support; trenching construction; steel cage production and hoisting; wall concrete pouring.

[0010] Furthermore, in step one, the scope of demolition of the box culvert top plate at the location of the ground-connected wall and the demolition of the box culvert vertical wall bottom plate at the location of the ground-connected wall is: 1.1m outward from the edge in the thickness direction of the proposed underground continuous wall; when backfilling the soil in layers, loess + 10% cement is used for backfilling in layers, and the bearing capacity of the foundation after backfilling is not less than 200kPa.

[0011] Furthermore, in step 2, when the pile positions are laid out, the diameter of the trench wall reinforcement piles is 0.8m, and the pile center spacing is 0.6m; after the laying out is completed, a steel plate with a number of pillars and circular holes is inserted into the soil as a pile position mark.

[0012] Furthermore, the pillars are made of 16mm threaded steel bars, and the thickness of the steel plate is not less than 4mm; when drilling, the high-pressure rotary jet pile drill bit is vertically passed through the circular hole on the steel plate fixed in the soil, and the diameter of the circular hole is 1.5-3cm larger than the diameter of the drill bit.

[0013] Furthermore, in step three, during the construction of the guide wall, part of the guide wall is made of cast-in-place reinforced concrete, and the other part of the underground continuous wall guide wall is formed by splicing a hollow aluminum frame and a panel. The panel is located in the middle of the hollow aluminum frame, and a number of vertical stiffening ribs are connected between the hollow aluminum frame and the panel. The inner ends of the hollow aluminum frame have end blocks, and the outer ends of the hollow aluminum frame have connecting blocks. The connecting blocks at both ends of the hollow aluminum frame are inserted into the U-shaped steel plate groove of the prefabricated reinforced concrete pier to form a splicing of several underground continuous wall guide walls.

[0014] Furthermore, the length of the hollow aluminum frame is ≤5m and the height is ≤1.3m.

[0015] Furthermore, in step three, after the guide wall construction is completed, a number of channel steel pillars are arranged on the opposite sides of adjacent guide walls, and the hollow square steel pipe diagonal braces are connected between two symmetrically arranged channel steel pillars, and the ends of the two symmetrically arranged channel steel pillars are connected with channel steel beams to form a steel frame support, and no less than three threaded steel bars are arranged on both sides above the channel steel beam. The steel frame support is hung on the guide wall through the threaded steel bars, and a number of steel frame supports are arranged 3-4m apart.

[0016] Furthermore, in step three, when the steel cage is manufactured and hoisted, the L-shaped steel cage is connected to the main load-bearing steel bars at both ends of the detachable diagonal brace. The detachable diagonal brace includes a hollow steel pipe, and both ends of the hollow steel pipe are connected to a steel base. The steel base and the upper connecting seat provided with a steel connecting block are connected through the I axis and the II axis.

[0017] Furthermore, the steel bar connecting block includes two symmetrically arranged connecting blocks, and a semicircular groove is opened at a single connecting block so that the two connecting blocks are sleeved on the outer periphery of the main force-bearing steel bars, and there are mounting holes on the sides of the connecting blocks, and bolts fix the two connecting blocks through the mounting holes.

[0018] The invention also discloses an underground continuous wall for reinforcing the trench wall of an abandoned box culvert crossing an area, which is obtained by construction according to a construction method for reinforcing the underground continuous wall of an abandoned box culvert crossing an area.

[0019] The beneficial effects of the present invention are:

[0020] 1. Reasonably arrange the dismantling process of abandoned box culverts to shorten the construction period;

[0021] 2. Use precise marking and drill hole alignment technology to ensure the accuracy of the construction of the trench wall reinforcement piles, prevent additional correction work caused by excessive pile center deviation, and reduce construction costs;

[0022] 3. The use of local prefabricated guide wall rapid closure technology and deep guide wall steel support technology not only improves construction efficiency but also improves construction quality, preventing construction safety accidents during underground continuous wall construction;

[0023] 4. The L-shaped steel cage detachable diagonal bracing technology is used to ensure the safety of the underground continuous wall steel cage during hoisting, while improving construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the construction process of the present invention.

[0025] Figure 2 This is a schematic diagram of the precise marking and drill bit technology of the present invention;

[0026] Figure 3 A three-dimensional diagram of the partially prefabricated guide wall prefabricated pier of the present invention;

[0027] Figure 4 A three-dimensional diagram of the partially prefabricated guide wall and prefabricated baffle of the present invention;

[0028] Figure 5 This is a schematic diagram of the local prefabricated guide wall rapid closure technology of the present invention;

[0029] Figure 6 It is a three-dimensional diagram of the steel support of the present invention;

[0030] Figure 7 This is a schematic diagram of the deep guide wall steel support technology of the present invention;

[0031] Figure 8 It is a three-dimensional diagram of the detachable diagonal brace of the present invention;

[0032] Fig. 9It is a schematic diagram of the detachable diagonal bracing technology of the L-shaped steel cage of the present invention.

[0033] Among them: 1-steel plate, 2-pillar, 3-circular hole, 4-high-pressure rotary jet pile drill bit, 5-precast reinforced concrete pier, 6-U-shaped steel plate groove, 7-hollow aluminum frame, 8-vertical stiffening rib, 9-panel, 10-end block, 11-connecting block, 12-channel steel pillar, 13-channel steel beam, 14-hollow square steel pipe diagonal brace, 15-threaded steel bar, 16-guide wall, 17-hollow steel pipe, 18-steel base, 19-upper connecting seat, 20-I axis, 21-II axis, 22-steel connecting block, 23-bolt, 24-main force-bearing steel bar, 25-steel block. DETAILED DESCRIPTION

[0034] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0035] Those skilled in the art should understand that, in the disclosure of the present invention, the orientation or position relationship indicated by the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0036] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0037] like Figure 1-Figure 9 The present invention provides a construction method for reinforcing an underground continuous wall of a trench wall in an abandoned box culvert crossing area, comprising the following steps:

[0038] S1: Dismantling of abandoned box culverts: dismantling the top plate of the box culvert at the location of the ground-connected wall in sequence; pumping out water and clearing silt; dismantling the top plate of the box culvert in the foundation pit between the ground-connected walls; dismantling the bottom plate of the vertical wall of the box culvert at the location of the ground-connected wall; and backfilling the soil in layers.

[0039] The scope of the demolition of the top plate of the box culvert at the location of the ground-connected wall and the bottom plate of the vertical wall of the box culvert at the location of the ground-connected wall is: 1.1m outward from the edge of the proposed underground continuous wall in the thickness direction. When the soil is backfilled in layers, loess + 10% cement is used for backfilling in layers, and the bearing capacity of the foundation after backfilling is not less than 200kPa.

[0040] S2: Trench wall reinforcement stage: pile position layout; drilling; high-pressure rotary jet grouting; pile formation and maintenance.

[0041] Among them, precise marking and drill hole alignment technology are used in pile position layout. The diameter of the trench wall reinforcement pile is 0.8m, and the distance between pile cores is 0.6m (the distance between adjacent pile cores should be 65% to 75% of the pile diameter). After the layout is completed, a steel plate 1 with four pillars 2 and a circular hole 3 is inserted into the soil as a pile position mark (such as Figure 1 The support 2 is made of 16mm threaded steel bars, and the thickness of the steel plate 1 is not less than 4mm. When drilling, the high-pressure jet pile drill bit 4 is vertically passed through the circular hole 3 on the steel plate 1 fixed in the soil to achieve precise hole alignment (such as Figure 1 As shown), the diameter of the circular hole 3 is 1.5-3 cm larger than the diameter of the drill bit.

[0042] S3: Underground continuous wall construction phase: guide wall construction; guide wall support; trenching construction; steel cage production and hoisting; wall concrete pouring.

[0043] Among them, the local prefabricated guide wall rapid closure technology is adopted during the construction of the guide wall. Most of the guide walls are cast-in-place reinforced concrete. A part of the underground continuous wall guide wall is formed by splicing a hollow aluminum frame 7 and a panel 9. The panel 9 is located in the middle of the hollow aluminum frame 7, and a number of vertical stiffening ribs 8 are connected between the hollow aluminum frame 7 and the panel 9. The inner ends of the hollow aluminum frame 7 have end blocks 10, and the outer ends of the hollow aluminum frame 7 have prefabricated baffles composed of connection blocks 11 (such as Figure 3 As shown), the connecting blocks 11 at both ends of the hollow aluminum frame 7 are inserted into the prefabricated reinforced concrete pier 5 (as shown Figure 2 The U-shaped steel plate groove 6 formed by the underground continuous wall guide wall is connected (as shown in FIG. Figure 4 As shown), the length of the hollow aluminum frame 7 is ≤5m and the height is ≤1.3m. The deep guide wall steel support technology is adopted for the guide wall support. After the guide wall 16 is constructed, a plurality of channel steel pillars 12 are arranged on the opposite sides of the adjacent guide walls 16. The hollow square steel pipe diagonal brace 14 is connected between the two symmetrically arranged channel steel pillars 12, and the ends of the two symmetrically arranged channel steel pillars 12 are connected with channel steel cross beams 13 to form a steel frame support (as shown). Figure 5 As shown), at least three threaded steel bars 15 are welded on both sides of the upper side of the channel steel beam 13, and the steel frame support is hung on the guide wall 16 through the threaded steel bars 15, and several steel frame supports are arranged 3-4m apart (as shown in FIG. Figure 6 shown).

[0044] The L-shaped steel cage with detachable diagonal bracing technology is used in the production and hoisting of the steel cage. The L-shaped steel cage is connected to the main force-bearing steel bars 24 at both ends of the detachable diagonal bracing to ensure stability (such as Figure 8 As shown), the detachable diagonal brace includes a hollow steel pipe 17, and both ends of the hollow steel pipe 17 are welded with a steel base 18 (as shown Figure 7 As shown), the steel base 18 and the upper connecting seat 19 with the steel bar connecting block 22 welded thereto are connected by the I axis 20, the II axis 21 and the steel block 25. When supporting, the steel bar connecting block 22 is tightened by the bolts 23.

[0045] Among them, the steel bar connecting block 22 includes two symmetrically arranged connecting blocks, and a semicircular groove is opened at a single connecting block so that the two connecting blocks are sleeved on the outer periphery of the main force-bearing steel bars 24, and there are mounting holes on the sides of the connecting blocks, and the bolts 23 fix the two connecting blocks through the mounting holes.

[0046] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to those of the present application fall within the protection scope of the present invention.

Claims

1. A construction method for reinforcing underground continuous walls in the trench wall of an abandoned box culvert crossing area, characterized in that: The following steps are involved: S1: Dismantling of abandoned box culverts: dismantling the top plate of the box culvert at the location of the ground-connected wall; pumping out water and clearing silt; dismantling the top plate of the box culvert in the foundation pit between the ground-connected walls; dismantling the bottom plate of the vertical wall of the box culvert at the location of the ground-connected wall; backfilling the soil in layers; S2: Trench wall reinforcement stage: pile position setting; drilling; high-pressure rotary jet grouting; pile formation and maintenance; S3: Underground continuous wall construction phase: guide wall construction; guide wall support; trenching construction; steel cage production and hoisting; wall concrete pouring.

2. The construction method of reinforcing the underground continuous wall of the abandoned box culvert crossing area according to claim 1 is characterized by: In step one, the scope of demolition of the top plate of the box culvert at the location of the ground-connected wall and the bottom plate of the vertical wall of the box culvert at the location of the ground-connected wall is: 1.1)m outward from the edge in the thickness direction of the proposed underground continuous wall; when backfilling the soil in layers, loess + 10% cement is used for backfilling in layers, and the bearing capacity of the foundation after backfilling is not less than 200kPa.

3. The construction method of reinforcing underground continuous wall of abandoned box culvert crossing area according to claim 1 is characterized by: In step 2, when the pile positions are laid out, the diameter of the trench wall reinforcement piles is 0.8 m and the distance between the pile centers is 0.6 m. After the laying out is completed, a steel plate (1) with a plurality of pillars (2) and circular holes (3) is inserted into the soil as a pile position mark.

4. The construction method of reinforcing underground continuous wall of abandoned box culvert crossing area according to claim 2 is characterized by: The support (2) is made of 16mm threaded steel bars, and the thickness of the steel plate (1) is not less than 4mm. When drilling, the high-pressure jet pile drill bit (4) is vertically passed through the circular hole (3) on the steel plate (1) fixed in the soil, and the diameter of the circular hole (3) is 1.5-3cm larger than the diameter of the drill bit.

5. The construction method of reinforcing underground continuous wall of abandoned box culvert crossing area according to claim 1 is characterized by: In step three, during the construction of the guide wall, part of the guide wall is made of cast-in-place reinforced concrete, and the other part of the underground continuous wall guide wall is formed by splicing a hollow aluminum frame (7) and a panel (9), the panel (9) is located in the middle of the hollow aluminum frame (7), and a number of vertical stiffening ribs (8) are connected between the hollow aluminum frame (7) and the panel (9), the inner two ends of the hollow aluminum frame (7) have end blocks (10), and the outer two ends of the hollow aluminum frame (7) have connecting blocks (11), and the connecting blocks (11) at both ends of the hollow aluminum frame (7) are inserted into the U-shaped steel plate groove (6) of the prefabricated reinforced concrete pier (5) to form a splicing of several underground continuous wall guide walls.

6. The construction method of reinforcing underground continuous wall of the abandoned box culvert crossing area according to claim 5 is characterized by: The length of the hollow aluminum frame (7) is ≤5m and the height is ≤1.3m.

7. The construction method of reinforcing underground continuous wall of abandoned box culvert crossing area according to claim 1 is characterized by: In step 3, after the construction of the guide wall (16) is completed, a plurality of channel steel pillars (12) are arranged on the opposite sides of the adjacent guide walls (16), and the hollow square steel pipe diagonal brace (14) is connected between two symmetrically arranged channel steel pillars (12), and the ends of the two symmetrically arranged channel steel pillars (12) are connected with a channel steel cross beam (13) to form a steel frame support, and at least three threaded steel bars (15) are arranged on both sides above the channel steel cross beam (13), and the steel frame support is hung on the guide wall (16) through the threaded steel bars (15), and the plurality of steel frame supports are arranged 3-4 meters apart.

8. The construction method of reinforcing underground continuous wall of abandoned box culvert crossing area according to claim 1 is characterized by: In step three, when the steel cage is manufactured and hoisted, the L-shaped steel cage is connected to the main force-bearing steel bars (24) at both ends of the detachable diagonal brace, and the detachable diagonal brace includes a hollow steel pipe (17), and both ends of the hollow steel pipe (17) are connected to a steel base (18), and the steel base (18) and an upper connecting seat (19) provided with a steel bar connecting block (22) are connected through an I axis (20) and an II axis (21).

9. The construction method of reinforcing underground continuous wall of the abandoned box culvert crossing area according to claim 8 is characterized by: The steel bar connecting block (22) comprises two connecting blocks which are symmetrically arranged, and a semicircular groove is provided at a single connecting block so that the two connecting blocks can be sleeved on the outer circumference of the main force-bearing steel bar (24), and the side of the connecting block has a mounting hole, and the bolts (23) are fixed to the two connecting blocks through the mounting hole.

10. An abandoned box culvert cross-region trench wall reinforcement underground continuous wall, characterized in that: The method for reinforcing the underground continuous wall of the trench wall in the abandoned box culvert crossing area according to any one of claims 1-9 is used for construction.

Images