A reinforced soil nailing structure for foundation pit support

Abstract

The utility model relates to building foundation pit support technical field, concretely is a kind of reinforcing bar soil nailing structure for foundation pit support, including slope top and slope face, the slope face is set in the one side of slope top, the middle part of slope face is evenly inserted with multiple reinforcing bar soil nailing, the reinforcing bar soil nailing includes stem, one end of stem is fixedly installed with bearing pad, the other end of stem is fixedly installed with soil cone, the surface of reinforcing bar soil nailing is equipped with spiral rib.The utility model is designed by spiral rib and axial side groove and soil nailing of soil cone, both can realize quick grouting by axial side groove, and increase the contact area with surrounding soil body by spiral rib, can form composite anchoring structure after slurry solidification, to greatly improve the pullout resistance to solve the problem of traditional soil nailing anchoring deficiency, and utilize soil cone to reduce implantation resistance, match the pore parameter of adaptive size, realize quick insertion installation, give consideration to supporting reliability and construction convenience.

Description

Technical Field

[0001] This utility model relates to the field of building foundation pit support technology, specifically a reinforced soil nail structure for foundation pit support. Background Technology

[0002] Reinforced soil nailing structures for foundation pit support are passive support components used during foundation pit excavation to reinforce slope soil and prevent landslides and collapses. The core is mainly composed of steel bars, which, together with grouting and connectors, form an overall anchoring system. In layman's terms, they are steel anchors driven into the soil to connect and tighten loose soil. They have extremely high usage frequency and value in the construction process.

[0003] Traditional reinforced soil nails are mostly smooth or have simple rib designs, which have insufficient pull-out resistance, small contact area with the grout and soil, and easy incomplete filling of grout, making it difficult to form a tight composite anchoring structure. This results in limited pull-out resistance and easy anchoring failure when facing deep foundation pits or complex soil layers, which has certain shortcomings. Utility Model Content

[0004] The purpose of this utility model is to provide a reinforced soil nail structure for foundation pit support, so as to solve the problems in the background art mentioned above.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: A reinforced soil nail structure for foundation pit support includes a slope top and a sloping surface. The sloping surface is located on one side of the slope top, and multiple reinforced soil nails are evenly inserted in the middle of the sloping surface. Each reinforced soil nail includes a rod body, with a bearing pad fixedly installed at one end of the rod body and an insertion cone fixedly installed at the other end of the rod body. The surface of the reinforced soil nail is provided with helical ribs, and an axial side groove is provided through one side of the rod body and the bearing pad. Connecting steel bars are provided between multiple reinforced soil nails that are laterally located on the same horizontal line.

[0006] In some embodiments, a retaining wall is fixedly installed on one side of the upper end of the slope, and a guardrail is fixedly installed on the upper end of the retaining wall.

[0007] In some embodiments, a drainage ditch is provided on one side of the lower end of the reinforced soil nail.

[0008] In some embodiments, the slope surface is provided with a plurality of drainage holes evenly distributed along its horizontal and vertical axes.

[0009] In some embodiments, the hole-forming angle of the reinforced soil nail is 15°, and the hole diameter of the reinforced soil nail is 13mm.

[0010] In some embodiments, the axial side groove is formed in the gap of the helical rib, and the soil-entry cone end of the rod is located inside the reinforced soil nail.

[0011] In some embodiments, the connecting steel bars and the bearing pads at the ends of the reinforced soil nails cooperate to connect multiple reinforced soil nails.

[0012] In some embodiments, the bearing pad has through holes on both sides of the middle part, and the connecting steel bars pass through the through holes.

[0013] This utility model has at least the following beneficial effects: 1. This utility model, when used, enables reinforced soil nails to have strong pull-out resistance and high construction efficiency. Through the design of the soil nail with spiral ribs, axial side grooves, and an insertion cone, the axial side grooves enable rapid grouting, while the spiral ribs increase the contact area with the surrounding soil, forming a composite anchoring structure after the grout solidifies. This significantly improves pull-out resistance, solving the problem of insufficient anchoring in traditional soil nails. Furthermore, the insertion cone reduces implantation resistance, and with appropriately sized drilling parameters, rapid insertion and installation are achieved, balancing support reliability and construction convenience.

[0014] 2. In use, this utility model provides stable support and waterproofing in synergy. By using a three-dimensional drainage system that blocks water at the top of the slope, drains water from the slope surface, and guides water from the bottom, the risk of soil water damage is reduced in advance. At the same time, combined with a mesh support structure of soil nails, connecting bars, and hanging netting, the system not only avoids local damage by dispersing stress and improves the slope's resistance to lateral pressure, but also maintains soil strength over the long term through the drainage system, thus achieving both short-term safety and long-term stability of the support system. Attached Figure Description

[0015] Figure 1 This is a cross-sectional view showing the overall positional relationship of the present invention; Figure 2 This is a front view showing the positional relationship of the slope surface of this utility model; Figure 3 This is a schematic diagram of the first three-dimensional structure of the reinforced soil nail of this utility model; Figure 4 This is a schematic diagram of the second three-dimensional structure of the reinforced soil nail of this utility model; Figure 5 For practical purposes Figure 4 Enlarged structural diagram of region A in the middle; Figure 6 This is a schematic diagram of the three-dimensional structure of the practical pressure bearing pad.

[0016] In the diagram: 1. Slope top; 11. Retaining wall; 12. Guardrail; 13. Slope surface; 14. Drainage ditch; 15. Drainage hole; 2. Reinforced soil nail; 21. Rod body; 22. Spiral rib; 23. Bearing pad; 24. Ground entry cone; 25. Axial side groove; 26. Connecting reinforcement; 27. Perforation. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] Example 1: Please refer to Figure 1 - Figure 6 This utility model provides a technical solution: a reinforced soil nail structure for foundation pit support, including a slope top 1 and a slope surface 13. The slope surface 13 is located on one side of the slope top 1. The feature is that multiple reinforced soil nails 2 are evenly inserted into the middle of the slope surface 13. Each reinforced soil nail 2 includes a rod 21, with a bearing plate 23 fixedly installed at one end of the rod 21 and an insertion cone 24 fixedly installed at the other end. The surface of the reinforced soil nail 2 is provided with spiral ribs 22. An axial side groove 25 is formed through one side of the rod 21 and the bearing plate 23. Connecting steel bars 26 are provided between multiple reinforced soil nails 2 located laterally on the same horizontal line. The axial side groove 25 is located in the gap of the spiral ribs 22. The insertion cone 24 end of the rod 21 is located inside the reinforced soil nail 2. The connecting steel bars 26 and the bearing plate 23 at the ends of the reinforced soil nails 2 cooperate to connect the multiple reinforced soil nails 2. Through holes 27 are formed on both sides of the middle of the bearing plate 23, and the connecting steel bars 26 pass through the through holes 27.

[0019] In this embodiment, the pull-out resistance can be significantly improved. The spiral ribs 22 on the surface of the rod 21, in conjunction with the axial side grooves 25 at the gaps between the spiral ribs 22, allow the grout to be fully filled and diffused during grouting, greatly increasing the contact area and bond strength between the rod 21 and the grout and soil, thus solving the problem of insufficient anchoring force of traditional soil nails. At the same time, the insertion cone 24 at the end of the rod 21 can reduce the insertion resistance and facilitate quick insertion and installation. The design of the perforation in the middle of the bearing pad 23 and the matching of the connecting steel bar 26 allows the connecting steel bar 26 to be passed through the perforations 27 of the bearing pad 23 at the ends of the rod 21, and then sequentially... Bundling allows for the lateral connection of multiple soil nails without complex procedures. The connecting steel bar 26, in conjunction with the bearing pad 23, connects the soil nails on the same horizontal line into a whole, forming a mesh support structure that facilitates subsequent mesh installation. This effectively disperses the force on individual soil nails, avoids local damage, and improves the overall lateral pressure resistance of the slope. The axial side groove 25 is opened in the gap of the spiral rib 22 and penetrates the rod body 21 and the bearing pad 23. This does not damage the force-bearing structure of the spiral rib 22 and guides the flow of grout for filling. At the same time, the end design of the soil-inserting cone 24 and the bearing pad 23 further optimizes the force transmission and implantation effect of the soil nails.

[0020] Example 2: As Figure 1 - Figure 2As shown, a retaining wall 11 is fixedly installed on one side of the upper end of the slope 1, and a guardrail 12 is fixedly installed on the upper end of the retaining wall 11. A drainage ditch 14 is opened on one side of the lower end of the reinforced soil nail 2. Multiple drainage holes 15 are evenly provided on the slope surface 13 along its horizontal and vertical directions. The drilling angle of the reinforced soil nail 2 is 15°, and the drilling diameter of the reinforced soil nail 2 is 13mm.

[0021] In this embodiment, the retaining wall 11 at the top of the slope can intercept surface water flow, preventing rainwater from directly scouring or seeping into the slope surface 13, thus reducing soil softening. The drainage holes 15 on the slope surface 13 can promptly drain water accumulated inside the soil, reducing pore water pressure. The drainage ditch 14 at the bottom quickly drains water accumulated around the slope, further improving soil stability. The 15° drilling angle of the reinforced soil nails balances anchoring force and construction difficulty, ensuring that the soil nails are effectively embedded in the stable soil layer while facilitating drilling and implantation operations. The 13mm drilling diameter on the slope surface matches the size of the soil nail rod 21, which can reduce the amount of drilling work while ensuring full contact between the grout and the hole wall, avoiding material waste. The guardrails 12 on the retaining wall 11 can prevent personnel or debris from falling, especially suitable for high-altitude operation scenarios such as foundation pit slopes, improving the construction safety factor.

[0022] Working principle: like Figure 1 - Figure 6 As shown, during use, after excavating the foundation pit to a depth of 5.50m at a slope ratio of 1:0.5, a retaining wall is set at the top of the slope to intercept surface runoff. At the same time, drainage holes are arranged along the slope at intervals of 3.00m × 2.00m, and drainage ditches are excavated at the bottom simultaneously. Through a three-dimensional drainage system of water blocking at the top of the slope, water drainage on the slope surface, and water guiding at the bottom, the pore water pressure of the soil is reduced in advance to avoid water erosion and softening of the slope. Then, drilling is carried out at a drilling angle of 15° and a drilling diameter of 130mm. During drilling, the surrounding building foundations are avoided. After drilling is completed, the reinforced soil nail with spiral ribs and axial side grooves is inserted into the hole. During the process, the soil cone at the end enters the soil first. Its shape can reduce the implantation resistance and achieve rapid insertion. The spiral ribs and side grooves on the surface of the rod leave space for grouting. The grout is cement grout with a water-cement ratio of 0.50 and grouting pressure of 0.5MPa. The grout flows along the axial side groove of the rod and can fully fill the gap between the hole wall and the rod. The spiral ribs and side grooves together increase the contact area between the rod and the grout, forming a composite anchoring structure of the rod, grout and soil after solidification, which greatly improves the pull-out resistance of the soil nail and solves the problem of insufficient anchoring of traditional soil nails.

[0023] Subsequently, 2Φ16 steel bars are connected using a bearing pad. During connection, the connecting steel bars 26 are passed through the through holes 27 of the bearing pad 23 at the ends of multiple horizontal rods 21, and then tied in sequence. This achieves the lateral connection of multiple horizontal soil nails without complicated procedures. The steel bars can connect the steel soil nails 2 on the same horizontal line into a whole. The bearing pad increases the stress area at the ends of the soil nails, and the connecting steel bars form a mesh skeleton to disperse the tension of individual soil nails and avoid local stress concentration. Then, according to the requirements, a mesh is installed, i.e., 1Φ16 steel bar is driven in every 2.00m to assist in the installation of the mesh, and it is effectively connected with the surface reinforcement. Finally, a collaborative support surface of steel soil nails 2, connecting bars and mesh is formed, which improves the overall lateral pressure resistance of the slope. The slope top retaining wall, combined with guardrails, not only intercepts accumulated water but also prevents people or debris from falling, improving construction and use safety. Drainage holes and open drainage ditches continuously drain water from the soil, maintaining soil strength. The spiral ribs and side groove structure of the soil nails maintain reliable bonding with the grouting body for a long time, ensuring the long-term stability of the support system.

[0024] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0025] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention.

Claims

1. A reinforced soil nailing structure for foundation pit support, comprising a slope top (1) and a sloping surface (13), wherein the sloping surface (13) is formed on one side of the slope top (1), characterized in that: Multiple reinforced soil nails (2) are evenly inserted in the middle of the slope surface (13). Each reinforced soil nail (2) includes a rod (21). One end of the rod (21) is fixedly installed with a pressure bearing plate (23), and the other end of the rod (21) is fixedly installed with a soil-inserting cone (24). The surface of the reinforced soil nail (2) is provided with spiral ribs (22). An axial side groove (25) is opened through one side of the rod (21) and the pressure bearing plate (23). A connecting steel bar (26) is provided between multiple reinforced soil nails (2) that are laterally located on the same horizontal line.

2. The reinforced soil nailing structure for foundation pit support according to claim 1, characterized in that: A retaining wall (11) is fixedly installed on one side of the top of the slope (1), and a guardrail (12) is fixedly installed on the top of the retaining wall (11).

3. The reinforced soil nailing structure for foundation pit support according to claim 2, characterized in that: A drainage ditch (14) is provided on one side of the lower end of the reinforced soil nail (2).

4. The reinforced soil nailing structure for foundation pit support according to claim 2, characterized in that: The slope surface (13) is provided with multiple drainage holes (15) evenly distributed along its horizontal and vertical directions.

5. A reinforced soil nailing structure for foundation pit support according to claim 1, characterized in that: The hole-forming angle of the reinforced soil nail (2) is 15°, and the hole-forming diameter of the reinforced soil nail (2) is 13mm.

6. The reinforced soil nailing structure for foundation pit support according to claim 1, characterized in that: The axial side groove (25) is opened in the gap of the spiral rib (22), and the end of the soil-entry cone (24) of the rod (21) is located inside the reinforced soil nail (2).

7. The reinforced soil nailing structure for foundation pit support according to claim 1, characterized in that: The connecting steel bar (26) and the bearing pad (23) at the end of the reinforced soil nail (2) cooperate to connect multiple reinforced soil nails (2).

8. The reinforced soil nailing structure for foundation pit support according to claim 1, characterized in that: The pressure bearing plate (23) has through holes (27) on both sides of the middle section, and the connecting steel bar (26) passes through the through holes (27).

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