A kind of slope protection structure for crab-shaped nodes

Abstract

The present invention discloses a crab-shaped node slope protection structure, comprising: precast nodes, a plurality of precast nodes are arranged at intervals along the longitudinal and transverse directions on the slope surface, the precast nodes include a plurality of legs extending outward from its center point, the legs include four first legs extending along the longitudinal and transverse directions, and an inclined second leg is provided between two first legs; an anchor hole is provided at the center point of the precast node; an anchor, the anchor passes through the anchor hole to anchor the precast node on the slope surface. Only by arranging precast nodes on the slope surface and using the multiple legs on the precast nodes to press and fix the slope surface, the protection of the slope can be realized, without setting structures such as lattice beams or slope protection nets, reducing the construction process and effectively shortening the construction period; under the condition of meeting the requirements of slope stability, the crab-shaped node structure slope protection structure saves materials, is convenient and efficient in construction, and has lower costs.

Description

Technical Field

[0001] The present invention relates to the technical field of slope protection, and particularly to a crab-shaped node slope protection structure. Background Art

[0002] In slope protection, the lattice reinforcement technology is often adopted. The main function of the lattice is to distribute the remaining sliding force or soil pressure and rock pressure of the slope to the anchor rods or cables at the lattice nodes, and then transmit them to the stable formation through the cables, so that the slope is in a stable state under the action of the anchoring force provided by the anchor rods or cables.

[0003] For example, an assembled rectangular lattice beam structure for a mountain highway slope disclosed in the publication number CN214657121U includes a plurality of precast nodes and a plurality of precast lattice beams. The precast nodes are arranged in an array, and the precast lattice beams are connected between two precast nodes; it is a lattice beam slope protection system. Among them, the precast nodes and precast lattice beams need to be assembled and connected on site, and the operation and construction are not very simple;

[0004] For example, an anchor mesh device for high-steep slope reinforcement and protection and its construction method disclosed in the publication number CN111501795B fixes a flexible mesh pad on the slope through a plurality of enlarged caps arranged in an array, so as to achieve slope protection; compared with the lattice beam slope protection system, it omits the lattice structure and forms a node slope protection system; however, the simplicity of operation and construction of this node slope protection system still has room for improvement. Summary of the Invention

[0005] In view of this, the present invention provides a crab-shaped node slope protection structure, which can solve the problem that the existing slope protection structures are relatively cumbersome during construction.

[0006] The technical solution of the present invention is realized as follows:

[0007] A crab-shaped node slope protection structure includes:

[0008] Precast nodes, a plurality of precast nodes are arranged at intervals in the longitudinal and transverse directions on the slope. The precast nodes include a plurality of legs extending outward from its center point. The legs include four first legs extending in the longitudinal and transverse directions, and an inclined second leg is provided between two first legs; an anchor hole is provided at the center point of the precast node;

[0009] An anchor, the anchor passes through the anchor hole to anchor the precast node on the slope.

[0010] As a further optional solution of the crab-shaped node slope protection structure, the angle between the first leg and the second leg is 45°.

[0011] As a further alternative solution for the crab-shaped node slope protection structure, the horizontal distribution spacing between the precast nodes and the length of the first leg are related by the following formula:

[0012]

[0013] In the formula, L x represents the horizontal distribution spacing between the precast nodes; l a represents the length of the first leg; F st is the design value of the slope stability safety factor; γ is the gravity density of the sliding body; θ is the soil pressure diffusion angle; is the slope angle; φ and C are the internal friction angle and cohesion of the slope rock layer / slope soil layer respectively.

[0014] As a further alternative solution for the crab-shaped node slope protection structure, the length l of the second leg b is a times that of the first leg length l .

[0015] As a further alternative solution for the crab-shaped node slope protection structure, the anchor is a cable bolt or a rock bolt.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: By only arranging precast nodes on the slope surface and using multiple legs on the precast nodes to press and fix the slope surface, the slope protection can be realized without arranging structures such as lattice beams or slope protection nets, reducing the construction procedures and effectively shortening the construction period; Under the condition of meeting the slope stability requirements, the crab-shaped node structure slope protection structure saves materials, is convenient and efficient in construction, and has lower costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 is a schematic structural diagram of a crab-shaped node slope protection structure of the present invention;

[0019] Figure 2 is Figure 1 the sectional view taken along the line E-E in

[0020] Figure 3 is Figure 1 the enlarged view of D1 in

[0021] Figure 4This is a schematic diagram of the distribution of the sliding area on the crab-shaped node slope protection structure of the present invention;

[0022] Figure 5 is Figure 4 the sectional view of H-H in

[0023] Figure 6 is Figure 4 the sectional view of J-J in

[0024] Figure 7 is Figure 4 the enlarged view of D2 in

[0025] Figure 8 This is a simplified diagram for the stability analysis of the crab-shaped node slope protection structure of the present invention.

[0026] In the figure: 1. Prefabricated node; 11. First leg; 12. Second leg; 2. Anchor. Detailed implementation manners

[0027] Next, the technical solutions in the embodiments of the present invention will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "vertical", "horizontal", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0029] In the present invention, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] Refer to Figures 1-8, which shows a slope protection structure of crab-shaped nodes, including precast nodes and anchor components; a plurality of precast nodes are arranged at intervals in the longitudinal and transverse directions on the slope surface. The precast nodes include a plurality of legs extending outward from their central points. The legs include four first legs extending in the longitudinal and transverse directions, and an inclined second leg is provided between two first legs; an anchor hole is provided at the central point of the precast node; the anchor component passes through the anchor hole to anchor the precast node on the slope surface. Among them, the precast node resembles a "crab" due to its leg structure, so it is called a crab-shaped node. This crab-shaped node slope protection structure is particularly suitable for slopes with relatively good properties and relatively high stability, such as moderately weathered, strongly weathered rock or hard soil bodies. By only setting precast nodes on the slope surface and using the multiple legs on the precast nodes to press and fix the slope surface, the protection of the slope can be achieved without setting structures such as grid beams or slope protection nets, reducing the construction process and effectively shortening the construction period; under the condition of meeting the slope stability requirements, this crab-shaped node structure slope protection structure saves materials, is convenient and efficient in construction, and has lower costs.

[0031] Specifically, the angle between the first leg and the second leg is 45°.

[0032] Specifically, the anchor component is a cable or a bolt.

[0033] The following briefly describes the stability problem of this crab-shaped node structure slope protection structure. Refer to Figures 4-6 , in Figure 5 , a cross-sectional view of the precast nodes longitudinally arranged and anchored on the slope is shown. Under the anchorage of the precast nodes, active earth pressure is formed on the slope. Among them, Pa1 is the overlapping area of active earth pressure, Pa2 is the non-overlapping area of active earth pressure, and Pa3 is the area without earth pressure action.

[0034] When the slope is in the limit equilibrium state, the rock (or soil) layers in the Pa1 area and the Pa2 area are in equilibrium under the action of active earth pressure. The interface between the Pa2 area and the Pa3 area (area without earth pressure action) may develop into a conical slip surface. Refer to Figure 5 and Figure 7 , at this time, along the H-H longitudinal section of the crab-shaped node structure slope protection structure, it will be in an overall (including the Pa3 area) equilibrium state under the action of active earth pressure (Pa1 area and Pa2 area), while the surface layer without earth pressure action along the J-J section (see Figure 6 ) may slide along the slip line ABCD, which is defined as the sliding area (Pa4), and the cross-section of the sliding area (K-K section) is Δabc.

[0035] According to the above analysis, in the crab-shaped node structure slope protection structure, along the J-J section (see Figure 6) The rock (or soil) mass in the sliding area may slide, and the rock (or soil) mass below is called the sliding body. Therefore, according to the slope stability analysis method in the "Code for Geotechnical Investigation", a representative cross-section (stability analysis unit) is taken for stability analysis (see Figure 4 and 6 ). The stability requirements of the sliding body shall meet the following stability coefficient conditions:

[0036] Equation (1): F s ≥F st

[0037] In Equation (1), F st is the design value of the stability safety factor, which is determined according to the engineering design requirements; F s is the calculated value of the stability safety factor, and the corresponding calculations can be made with reference to Figure 8 as follows:

[0038] ① The normal direction vector of the sliding surface aa'c'c in the sliding area

[0039] Vector and are both in the plane of the sliding surface aa'c'c. Therefore, the normal vector of the sliding surface aa'c'c can be expressed as:

[0040]

[0041] In Equation (2), are the unit vectors of the coordinate axes x, y, and z respectively; θ is the soil pressure diffusion angle; is the slope angle.

[0042] ② The normal pressure N (kN / m) on the sliding surfaces aa'c'c and bb'c'c

[0043]

[0044] In Equation (3), G is the gravity of the sliding body per unit length; γ is the gravity density of the sliding body; is the bottom length of Δabc.

[0045] ③ The anti-sliding force R (kN / m) on the sliding surfaces aa'c'c and bb'c'c (considering the case of a homogeneous slope). The anti-sliding force R is parallel to the vector and

[0046]

[0047] In Equation (4), φ and C are the internal friction angle and cohesion of the rock (or soil) layer on the slope surface respectively.

[0048] ④ The sliding force T (kN / m) of the sliding body

[0049] The sliding force T of the sliding body is parallel to the vector That is, there is

[0050]

[0051] ⑤ Calculated value F of the slope stability safety factor s

[0052]

[0053] The above formula is formula (6). In formula (6), L represents the length of the sliding body along the slope surface.

[0054] ⑥ Relationship between the horizontal distribution spacing of the nodes meeting the slope stability requirements and the structural geometric parameters

[0055] According to formula (1) and formula (6), the relationship meeting the slope stability requirements can be obtained as follows

[0056]

[0057] From Figure 4 and Figure 7 it can be seen that the horizontal distribution spacing between the precast nodes is L x , the length of the first leg of the precast node is l a , and the horizontal width of the sliding body (i.e., the bottom edge of the sliding body section Δabc) is

[0058]

[0059] From formula (7) and (8), we get

[0060]

[0061] Or

[0062]

[0063] That is, there is

[0064] Therefore, the relationship between the horizontal distribution spacing between the precast nodes and the length of the first leg is selected according to formula (9); the longitudinal spacing L y of the precast nodes can be selected as the longitudinal distribution spacing of the corresponding nodes in the conventional lattice beam slope protection system, or can be selected to be equal to the horizontal distribution spacing L x in this crab-shaped node slope protection structure; the length l b of the second leg in the precast node can be selected to be equal to or approximately equal to the length l a of times, the length ratio of the first leg and the second leg approaches the Pythagorean theorem, improving the evenness of force distribution.

[0065] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A crab-shaped node slope protection structure, characterized in that, Including: Prefabricated nodes, multiple prefabricated nodes are arranged at intervals along the longitudinal and transverse directions on the slope surface. The prefabricated nodes include multiple legs extending outward from their center points. The legs include four first legs extending along the longitudinal and transverse directions, and an inclined second leg is provided between two first legs; an anchor hole is provided at the center point of the prefabricated node; Anchoring members, the anchoring members pass through the anchor holes to anchor the prefabricated nodes on the slope surface; The relationship between the horizontal distribution spacing between the prefabricated nodes and the length of the first leg is expressed by the following formula: In the formula, represents the horizontal distribution spacing between precast joints; represents the length of the first leg; is the design value of the slope stability safety factor; is the gravity density of the sliding mass; is the earth pressure dispersion angle; is the slope inclination angle; and C are the internal friction angle and cohesion of the slope rock stratum / slope soil layer respectively.

2. The crab-shaped node slope protection structure according to claim 1, characterized in that, The angle between the first leg and the second leg is 45°.

3. The crab-shaped node slope protection structure according to claim 2, characterized in that, The length of the second leg is times the length of the first leg.

4. The crab-shaped node slope protection structure according to claim 1, characterized in that, The anchoring members are anchor cables or anchor rods.

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