Anchor rod soil nailing wall slope support reinforcing mesh fixing method

Abstract

The invention relates to the technical field of geotechnical engineering slope support, in particular to an anchor rod soil nailing wall slope support reinforcing mesh fixing method. According to the technical scheme, the method comprises the following treatment steps of 1, slope surface pretreatment, wherein a slope surface and a top slope surface are cleaned; 2, drilling positions are determined, specifically, drilling is conducted on the top slope surface and the slope surface; 3, anchor rod soil nails are installed, and a reinforcing mesh layer is laid; fourthly, U-shaped steel bars are mounted, wherein mounting holes allowing the U-shaped steel bars to be inserted are formed in the slope soil body, and the semicircular top face is exposed; fifthly, the reinforcing mesh layer and the U-shaped steel bars are bound and fixed, wherein horizontal bars and longitudinal bars of the reinforcing mesh layer are bound to the U-shaped steel bars; and 6, pouring of a surface layer. The U-shaped reinforcing steel bars are adopted for fixing and supporting the reinforcing mesh, the thickness of a protective layer of the reinforcing mesh and a slope soil body is effectively controlled, it is also guaranteed that the slope reinforcing mesh is located on the same plane, the overall stability of supporting is improved, the slope appearance after construction is good, and the construction safety performance is high.

Description

Technical Field

[0001] The invention relates to the technical field of geotechnical engineering slope support, and in particular to a method for fixing a steel bar mesh for anchor rod soil nail wall slope support. Background Art

[0002] At present, civil and public buildings generally require underground space. The basement is generally about 2 floors and more than 5 meters deep. In the process of deep foundation pit excavation, it is very important to ensure the engineering quality of slope support. Projects with large land areas such as residential and commercial plazas generally use slope reduction and anchor rod soil nail wall support. The construction of soil nail wall includes the placement of surface steel mesh.

[0003] Normally, after the soil nails on the top of the slope are driven in, a full-length steel bar is tied to the outside of the soil nails. The longitudinal steel bars on the slope are fixed on the full-length steel bars and hang down by their own weight. Then the horizontal bars are tied to the longitudinal bars. This can easily damage the driven soil nails, and there is no protective layer between the steel mesh and the soil, and the hanging steel bars can easily hurt people.

[0004] Due to the inclination of the slope, it is difficult to fix the steel mesh. At the same time, a protective layer is required between the steel mesh and the slope soil to prevent the steel bars from rusting and reducing the support strength. The existing anchor soil nail wall slope support steel mesh fixing method cannot meet the above construction requirements. In view of this, the present application proposes a method for fixing the anchor soil nail wall slope support steel mesh with high support strength of the slope steel mesh on the same plane. Summary of the invention

[0005] The purpose of the present invention is to solve the problems existing in the background technology and to provide a method for fixing a slope support steel mesh of an anchor soil nail wall with high support strength on the same plane.

[0006] The technical solution of the present invention is a method for fixing a steel mesh for supporting a slope with an anchor rod soil nail wall, comprising the following processing steps:

[0007] Step 1: Slope surface pretreatment: clean the slope surface and top slope surface to ensure that the slope surface is flat and solid, use a high-pressure water gun to wash the slope surface to remove dust and soil on the slope surface, so that the slope surface exposes fresh rock and soil surface to ensure the bonding strength between the steel mesh layer and the slope surface;

[0008] Step 2: Determine the drilling position: Drill holes on the top slope and slope surface according to the construction specifications and requirements to ensure that the anchor soil nails are installed and play an anchoring role;

[0009] Step 3: Installation of anchor soil nails and laying of steel mesh layer: Insert the anchor soil nails into the drilled holes, inject high-strength anchoring agent into the holes, fill the holes with anchoring agent, ensure that the anchor soil nails are tightly bonded to the hole wall, and after inserting the anchor soil nails, use anchor soil nail tensioning equipment to pre-tension them;

[0010] Lay a steel mesh layer on the slope;

[0011] Step 4: Installation of U-shaped steel bars: Based on the thickness of the surface concrete in the support design, take half of the designed thickness as the radius of the U-shaped steel bar, and open an installation hole on the slope soil for the vertical insertion of the U-shaped steel bar to expose the semicircular top surface;

[0012] Step 5: Tie and fix the steel mesh layer and the U-shaped steel bars: Tie the horizontal and longitudinal bars of the steel mesh layer to the U-shaped steel bars to fix and suspend them. The suspending distance is based on the highest point at the vertical distance from the slope surface to ensure that the thinnest part of the casting surface meets the design requirements.

[0013] Step 6: Pouring of surface layer: Spraying of surface concrete is carried out in two times. The first spraying is close to the thickness of the steel mesh layer, and the second spraying reaches the designed thickness.

[0014] Optionally, a top slope hole is provided on the top slope surface, and a plurality of side slope holes are provided in the slope surface. The top slope holes and the side slope holes are respectively perpendicular to the top slope surface and the slope surface, and the deviation is controlled within ±3°.

[0015] Optionally, the anchor soil nails include slope top soil nails and side slope soil nails, the slope top soil nails are installed in the top slope holes, the side slope soil nails are installed in the side slope holes, and the slope top soil nails and the side slope soil nails are respectively protrudingly arranged.

[0016] Optionally, the steel mesh layer includes continuous steel bars connected to a plurality of groups of soil nails on the top of the slope, and the U-shaped steel bars are distributed in any one of a square arrangement and a plum blossom arrangement;

[0017] The spacing between the multiple U-shaped steel bars is 1m, and the number of the U-shaped steel bars is an integer multiple of the steel bar spacing.

[0018] Optionally, the semicircular arc tops of multiple groups of U-shaped steel bars arranged on the same slope are controlled to be on the same plane.

[0019] Optionally, the high-pressure water gun used in step 1 washes the slope surface at a pressure of 2-3 MPa until there is no obvious dust and soil remaining on the slope surface;

[0020] For rock slopes, first use a pneumatic pick to remove loose rocks, then use a high-pressure water gun to flush them.

[0021] Optionally, the anchoring agent in step 3 is any one of a resin anchoring agent and a cement-based anchoring agent;

[0022] The pre-tensioning stress of the anchor soil nail tensioning equipment is 30%-50% of the designed tensile strength, which is used to generate pre-tightening force in the slope soil to ensure the anchoring effect;

[0023] Optionally, a layer of anti-corrosion lubricant is applied to the contact connection portion between the U-shaped steel bar and the steel mesh layer to reduce connection friction and corrosion.

[0024] Compared with the prior art, the present invention has the following beneficial technical effects:

[0025] The present invention optimizes the connection mode between the steel mesh and the anchor soil nails and adopts U-shaped steel bars as the auxiliary parts for connecting the two. It not only effectively controls the thickness of the protective layer between the steel mesh and the slope soil, but also ensures that the steel mesh on the slope surface is in the same plane, thereby improving the overall stability of the support, significantly enhancing the stability and reliability of the slope support structure, reducing the project cost, and improving the project quality.

[0026] Furthermore, by coating the connection between the steel mesh layer and the U-shaped steel bar with an anti-corrosion lubricant, it is used to reduce the friction and corrosion of the connection and extend the service life of the U-shaped steel bar. This is beneficial for the steel mesh to slide and adjust to a certain extent relative to the anchor soil nails when the slope soil undergoes a slight deformation, thus avoiding the connection damage caused by local stress concentration.

[0027] In summary, the present invention adopts U-shaped steel bars to fix the support steel mesh, which not only effectively controls the thickness of the protective layer between the steel mesh and the slope soil, but also ensures that the slope steel mesh is in the same plane, thereby improving the overall stability of the support. The slope surface after construction has a better appearance and high construction safety performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Provide a structural schematic diagram of the present invention;

[0029] Figure 2 for Figure 1 Schematic diagram of the cross-section structure at AA in the middle;

[0030] Figure 3 for Figure 1 Schematic diagram of the cross-section structure viewed from the front at BB in the middle.

[0031] Reference numerals:

[0032] 1. Slope soil; 11. Top slope surface; 110. Top slope hole; 12. Slope surface; 120. Slope hole; 130. Installation hole;

[0033] 2. Anchor soil nails; 21. Top soil nails; 22. Side slope soil nails;

[0034] 3. Steel mesh layer; 31. Through-length reinforcement; 32. Horizontal reinforcement; 33. Longitudinal reinforcement;

[0035] 4. U-shaped steel bars. DETAILED DESCRIPTION

[0036] The technical solution of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0037] The components of the embodiments of the present disclosure generally described and shown in the drawings herein may be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present disclosure provided in the drawings is not intended to limit the scope of the present disclosure claimed, but merely represents selected embodiments of the present disclosure.

[0038] Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present disclosure.

[0039] In the description of the present disclosure, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure 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 operated in a specific orientation, and therefore cannot be understood as a limitation on the present disclosure.

[0040] In the description of the present disclosure, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0041] Example

[0042] like Figure 1-3 As shown, a method for fixing a steel mesh for supporting a slope with an anchor rod soil nail wall proposed by the present invention comprises the following processing steps:

[0043] Step 1: Slope surface pretreatment: Clean the slope surface 12 and the top slope surface 11 to ensure that the slope surface is flat and solid, and use a high-pressure water gun to wash the slope surface at a pressure of 2.5MPa until there is no obvious dust and soil residue on the slope surface;

[0044] For rock slopes, loose rocks are first removed with a pneumatic pick, and then washed with a high-pressure water gun to remove dust and soil on the slope surface, exposing the fresh rock and soil surface to ensure the bonding strength between the steel mesh layer 3 and the slope surface.

[0045] The pre-tensioning stress of the anchor soil nail tensioning device is more than 45% of the designed tensile strength, which is used to generate a pre-tightening force in the slope soil 1 to ensure the anchoring effect.

[0046] In this step: follow the above-mentioned slope pretreatment method, use excavators, manual tools and high-pressure water guns to clean and flush the slope surface to ensure that the slope surface is flat, solid and free of debris and dust.

[0047] Reference Figure 2 As shown, step 2: determine the drilling position: drill holes on the top slope surface 11 and the slope surface 12 respectively according to the construction specifications and requirements, the top slope surface 11 is provided with a top slope hole 110, and the slope surface 12 is provided with a plurality of side slope holes 120, the top slope hole 110 and the side slope hole 120 are respectively perpendicular to the top slope surface 11 and the slope surface 12, and the deviation is controlled within ±3°, and the anchor soil nail 2 is installed corresponding to the drill hole to ensure that the anchor soil nail 2 is installed and plays an anchoring role.

[0048] In this step, according to the design requirements, use a drilling machine to drill holes on the slope, strictly control the depth, diameter and verticality of the holes, and clean up the debris and dust in the hole in time after each hole is drilled to prepare for the installation of anchor soil nails.

[0049] like Figure 2 As shown, step three: installation of anchor soil nail piece 2 and laying of steel mesh layer 3: anchor soil nail piece 2 includes slope top soil nail 21 and side slope soil nail 22, the anchor soil nail piece 2 is inserted into the drilled hole, the slope top soil nail 21 is installed in the top slope hole 110, the side slope soil nail 22 is installed in the side slope hole 120, and the slope top soil nail 21 and the side slope soil nail 22 are respectively protruded, and a high-strength anchoring agent is injected into the hole. The high-strength anchoring agent adopts a cement-based anchoring agent, and the anchoring agent fills the drilled hole to ensure that the anchor soil nail is tightly bonded to the hole wall. After the anchor soil nail piece 2 is inserted, it is pre-tensioned by using an anchor soil nail tensioning device;

[0050] A steel mesh layer 3 is laid on the slope surface, and the steel mesh layer 3 includes full-length reinforcement bars 31 tied and connected to a plurality of groups of soil nails 21 on the top of the slope.

[0051] In this step, the anchoring agent is prepared according to the prescribed proportion and method, and then injected into the hole to ensure that the anchoring agent fills the borehole. After the anchor soil nail 2 is inserted, it is immediately pre-tensioned using the anchor soil nail tensioning equipment. After reaching the designed pre-tensioning stress, the anchor soil nail is locked.

[0052] Reference Figure 3As shown, step four: installation of U-shaped steel bars 4: combined with the thickness of the surface concrete in the support design, half of the design thickness is taken as the radius of the U-shaped steel bars 4, and a mounting hole 130 for vertical insertion of the U-shaped steel bars 4 is opened on the slope soil 1, exposing the semi-circular arc top surface, and the semi-circular arc tops of multiple groups of U-shaped steel bars 4 arranged on the same slope are controlled to be on the same plane, and the U-shaped steel bars 4 are distributed in any form of a square arrangement and a plum blossom arrangement; the spacing between multiple U-shaped steel bars 4 is 1m, and the number of U-shaped steel bars 4 is an integer multiple of the steel bar spacing.

[0053] In this step, the U-shaped steel bar 4 is inserted into the installation hole 130, and the protruding heights of the multiple groups of U-shaped steel bars 4 are kept on the same horizontal line using a construction line. At the same time, the height of the U-shaped steel bar 4 protruding from the slope is based on the highest point of the vertical distance from the slope. Because there is a flatness difference in slope repair, in order to ensure that the thinnest part of the surface layer meets the design requirements, the highest point of the vertical distance from the slope is used as the standard.

[0054] Step 5: Binding and fixing the steel mesh layer 3 and the U-shaped steel bars 4: Bind the horizontal bars 32 and the longitudinal bars 33 of the steel mesh layer 3 to the U-shaped steel bars 4 to fix and suspend them. The suspending distance is based on the highest point of the vertical distance from the slope surface to ensure that the thinnest part of the casting surface layer meets the design requirements; Apply a layer of anti-corrosion lubricant to the contact connection between the U-shaped steel bars 4 and the steel mesh layer 3 to reduce the friction and corrosion of the connection;

[0055] Step 6: Casting of surface layer: The spraying of surface layer concrete is carried out in two times. The first spraying is close to the thickness of steel mesh layer 3, and the second spraying reaches the designed thickness.

[0056] The above specific embodiment is only an optional embodiment of the present invention. Based on the technical solution of the present invention and the relevant inspiration of the above embodiment, those skilled in the art can make various alternative improvements and combinations to the above specific embodiment.

Claims

1. A method for fixing a steel mesh for anchor soil nail wall slope support, characterized in that: The processing steps include: Step 1: Slope surface pretreatment: clean the slope surface (12) and the top slope surface (11) to ensure that the slope surface is flat and solid, and use a high-pressure water gun to wash the slope surface to remove dust and soil on the slope surface, so that the slope surface exposes fresh rock and soil surface to ensure the bonding force between the steel mesh layer (3) and the slope surface; Step 2: Determine the drilling position: Drill holes on the top slope surface (11) and the slope surface (12) respectively according to the construction specifications and requirements to ensure that the anchor soil nail member (2) is installed and plays an anchoring role; Step 3: Installation of the anchor soil nail (2) and laying of the steel mesh layer (3): Insert the anchor soil nail (2) into the drilled hole, inject a high-strength anchoring agent into the hole, fill the drilled hole with the anchoring agent, ensure that the anchor soil nail is tightly bonded to the hole wall, and after inserting the anchor soil nail (2), use the anchor soil nail tensioning equipment to pre-tension it; Laying a steel mesh layer (3) on the slope; Step 4: Installation of the U-shaped steel bar (4): Based on the thickness of the surface concrete in the support design, half of the designed thickness is taken as the radius of the U-shaped steel bar (4), and a mounting hole (130) for vertically inserting the U-shaped steel bar (4) is opened on the slope soil (1), exposing the semicircular arc top surface; Step 5: Binding and fixing the steel mesh layer (3) and the U-shaped steel bars (4): Bind the horizontal bars (32) and the longitudinal bars (33) of the steel mesh layer (3) to the U-shaped steel bars (4) to fix and suspend them. The suspending distance is based on the highest point at a vertical distance from the slope surface to ensure that the thinnest part of the casting surface layer meets the design requirements. Step 6: Casting of the surface layer: The spraying of the surface layer concrete is carried out in two times. The first spraying is carried out to a thickness close to that of the steel mesh layer (3), and the second spraying is carried out to reach the designed thickness.

2. The method for fixing the anchor soil nail wall slope support steel mesh according to claim 1 is characterized in that: The top slope surface (11) is provided with a top slope hole (110), and the slope surface (12) is provided with a plurality of groups of side slope holes (120). The top slope holes (110) and the side slope holes (120) are respectively perpendicular to the top slope surface (11) and the slope surface (12), and the deviation is controlled within ±3°.

3. A method for fixing a steel mesh for anchor soil nail wall slope support according to claim 2, characterized in that: The anchor soil nail member (2) comprises a slope top soil nail (21) and a side slope soil nail (22), wherein the slope top soil nail (21) is installed in a top slope hole (110), and the side slope soil nail (22) is installed in a side slope hole (120), and the slope top soil nail (21) and the side slope soil nail (22) are respectively protrudingly arranged.

4. A method for fixing a steel mesh for anchor soil nail wall slope support according to claim 3, characterized in that: The steel mesh layer (3) comprises continuous steel bars (31) connected by binding with a plurality of groups of soil nails (21) at the top of the slope, and the U-shaped steel bars (4) are distributed in any one of a square arrangement and a plum blossom arrangement; The spacing between the plurality of U-shaped steel bars (4) is 1 m, and the number of the U-shaped steel bars (4) is an integer multiple of the spacing between the steel bars.

5. The method for fixing the anchor soil nail wall slope support steel mesh according to claim 4, characterized in that: The semicircular arc tops of multiple groups of U-shaped steel bars (4) arranged on the same slope are controlled to be on the same plane.

6. The method for fixing the steel mesh for anchor soil nail wall slope support according to claim 1 is characterized in that: The high-pressure water gun used in step 1 washes the slope surface at a pressure of 2-3 MPa until there is no obvious dust and soil remaining on the slope surface; For rock slopes, first use a pneumatic pick to remove loose rocks, then use a high-pressure water gun to flush them.

7. The method for fixing the steel mesh for anchor soil nail wall slope support according to claim 1 is characterized in that: The anchoring agent in step 3 is any one of a resin anchoring agent and a cement-based anchoring agent; The pre-tensioning stress of the anchor soil nail tensioning device is 30%-50% of the designed tensile strength, and is used to generate a pre-tightening force in the slope soil (1) to ensure the anchoring effect.

8. The method for fixing the anchor soil nail wall slope support steel mesh according to claim 1, characterized in that: A layer of anti-corrosion lubricant is applied to the contact connection portion between the U-shaped steel bar (4) and the steel mesh layer (3) to reduce connection friction and corrosion.

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