Bamboo geocell and manufacturing method thereof

Abstract

The invention relates to the technical field of engineering reinforcing materials, in particular to a bamboo geocell and a manufacturing method thereof.The bamboo geocell comprises a three-dimensional net-shaped structure formed by connecting a plurality of geocell walls at joints, and the three-dimensional net-shaped structure forms a plurality of deformable geocell spaces used for containing filler; wherein the grid chamber walls are flexible composite strips formed by weaving bamboo strips, and the composite strips are arranged to be provided with holes distributed in a dot matrix mode so as to form a hollow grid structure. Compared with a traditional macromolecule geocell wall, the hollow grating type geocell wall formed by sewing, bonding and compounding the bamboo split strips is light in weight and high in strength, a three-dimensional meshing interface and a horizontal drainage channel are created for the geocell wall, the problems that the macromolecule geocell interface is weak in friction and poor in drainage function are solved, renewable biomass materials are adopted, and the environment is protected. Bamboo is used for replacing plastic, carbon emission can be reduced, natural degradation can be achieved, no environmental burden is caused after scrapping, and meanwhile the economic development of regions with rich bamboo resources and backward economy is promoted.

Description

Technical Field

[0001] This invention relates to the field of engineering reinforcement materials technology, and more specifically to bamboo geocells and their manufacturing methods. Background Technology

[0002] Geocells, as a three-dimensional mesh honeycomb structure, significantly improve the bearing capacity of soil, distribute loads, and constrain lateral deformation by unfolding and filling it with granular materials. They are widely used in foundation reinforcement and protection for highways, railways, dams, slopes, and other engineering projects. To date, this field has been dominated by geocells made of polymer materials such as high-density polyethylene (HDPE).

[0003] Although polymer cell grids have advantages such as being lightweight, tough, and resistant to chemical corrosion, their smooth sheet walls with only a few openings result in insufficient interfacial properties, limited drainage capacity, and hinder plant root penetration, making it difficult to achieve an organic combination of engineering protection and ecological restoration. Furthermore, their raw materials are derived from non-renewable petroleum resources, resulting in a high carbon footprint throughout their life cycle. They also face the risk of aging under long-term ultraviolet radiation and are difficult to degrade after disposal, potentially causing white pollution, which contradicts the current concept of promoting green and sustainable infrastructure construction.

[0004] Although there have been some attempts in the market to use natural materials such as bamboo and wood, these products are bulky, cannot be rolled up for transportation, and are easily damaged at the joints. They also cannot solve the contradictions between interface interlocking and horizontal drainage. Therefore, no non-polymer products have yet been able to pose a substantial challenge to the mainstream status of HDPE cells. Summary of the Invention

[0005] In view of the technical problems existing in the geocells of the prior art, the first aspect of the present invention proposes a technical solution: a bamboo geocell, which is composed of multiple cell walls connected to each other at the nodes to form a three-dimensional mesh structure, wherein the three-dimensional mesh structure forms multiple deformable cell spaces for accommodating filler material. The cell wall is a flexible composite strip woven from bamboo strips, and the composite strip is configured with pores distributed in a dot matrix to form a hollow grid structure. This makes the cell wall macroscopically form a non-sealed network-like plane that allows filler to be embedded and water to flow through the deformable cell space. The deformable cell space is configured to allow compression to fit the cell wall or expansion to accommodate the filler. The flexible composite strip material includes at least three layers of bamboo strips: a first bamboo strip layer in the middle layer and a second and third bamboo strip layer on both sides of the middle layer. Adjacent bamboo strip layers are fixed to each other by an adhesive layer. Each bamboo strip layer is formed by stitching multiple bamboo strips together in a direction perpendicular to their grain, so that there is a gap δ between adjacent bamboo strips. In the direction perpendicular to the bamboo strip layer, the bamboo strips of the first bamboo strip layer form a predetermined angle with the bamboo strips of the second and third bamboo strip layers. In the deployed state of the geocell, the bamboo strips in the second and third bamboo strip layers extend circumferentially along the deformable geocell space to provide circumferential tensile strength, while the bamboo strips in the first bamboo strip layer extend vertically along the deformable geocell space to provide vertical support for the second and third bamboo strip layers.

[0006] Preferably, in the bamboo strip layer, a predetermined gap δ is formed between the bamboo strips through the seam, so that the bamboo strip layer forms a grid structure, and the size of the gap δ is based on the characteristic particle size of the filler. Design a system that satisfies the following relationship: δ≤(1 / 2~1 / 3) × ,in It is the particle size corresponding to 85% of the weight in the filler particle distribution curve.

[0007] Preferably, the gap δ = 1~5mm; In the first bamboo strip layer, the average gap δ1 between the bamboo strips is greater than the average gap δ2 between the bamboo strips in the second and third bamboo strip layers, making the bamboo strips in the second and third bamboo strip layers more tightly arranged than those in the first bamboo strip layer, thereby improving the circumferential tensile strength.

[0008] Preferably, the first bamboo strip layer has a first strip-shaped gap distributed along a first direction, and the second and third bamboo strip layers have a second strip-shaped gap distributed along a second direction. The flexible composite strip material formed by the first, second, and third bamboo strip layers has a lattice-distributed pore structure consisting of overlapping areas of the first and second strip-shaped gaps. The pores are used to allow water or plant roots in the deformable cell space to pass through and to increase the bonding force with the filler.

[0009] Preferably, the bamboo strips are made from the outer green part of the bamboo wall; and / or, the bamboo strips have a thickness of 1.2±0.3mm, a width of 15±3mm, a length of 2~5m, a tensile strength of not less than 180MPa, an elastic modulus of not less than 15GPa, and an elongation at break of 1.5~3.0%.

[0010] Preferably, the bamboo strips in the first bamboo strip layer have a grain direction that is orthogonal to the bamboo strips in the second and third bamboo strip layers.

[0011] Preferably, the stitch spacing is 30-80mm, and the stitch is 10-20 count hemp thread or nylon fiber with a linear density between 200 and 500 denier.

[0012] Preferably, the adhesive layer includes an amino resin adhesive layer, the adhesive strength of which is greater than the tensile strength of the bamboo strips, and the flexural modulus is 8~12GPa, which matches the mechanical properties of the bamboo strips, so that the flexible composite strip formed by bonding multiple bamboo strips maintains overall flexibility. The adhesive layer is configured to form a continuous and uniform thin layer of amino resin between two adjacent bamboo strip layers under a preset pressure of 0.4~0.6MPa, so that the two adjacent bamboo strip layers form mechanical interlocking and chemical bonding.

[0013] Preferably, multiple parallel cell walls are connected by nodes along a predetermined direction to form geocells of a predetermined size, wherein adjacent cell walls are separated by multiple nodes to form multiple deformable cell spaces, constituting a three-dimensional network structure. The nodes are divided into odd rows and even rows, and the multiple first nodes in the odd rows and the multiple second nodes in the even rows are arranged alternately, so that the deformable cell space can be compressed to fit the cell wall or expanded to a space that can be filled with filler. The node is configured to allow the two connected cell walls to bend when the deformable cell space deforms, and to give the two cell walls a tensile strength at the node.

[0014] A second aspect of this invention provides a technical solution, such as the manufacturing method of the bamboo geocell described above, comprising the following steps: Step S1: Split the bamboo into single radial bamboo strips of predetermined size, and then treat them with anti-corrosion, anti-insect and drying methods for later use. Step S2: Arrange the bamboo strips prepared in step S1 in parallel and weave them with sewing thread to form a bamboo strip strip for later use. The gap between adjacent bamboo strips is controlled at 1~5mm, and the spacing of the sewing thread is controlled at 30~80mm. Step S3: Cut the bamboo strips prepared in step S2 into strips with a width equal to the height of the cell wall along the direction parallel to the weaving line to form the middle bamboo strips. Cut the bamboo strips prepared in step S2 into strips with a width equal to the height of the cell wall along the direction parallel to the bamboo strips to form the outer bamboo strips. Step S4: Apply amino resin adhesive to the bonding surfaces of the middle bamboo strip and the two outer bamboo strips, so that the two outer bamboo strips sandwich the middle bamboo strip, and pressurize and cure under a pressure of 0.4~0.6MPa to form a flexible composite strip with the same height as the cell wall. Step S5: Adjacent cell walls are connected to each other by HDPE fasteners and ultrasonic welding to form a three-dimensional mesh structure, forming a deformable cell space between multiple cell walls; In step S5, the plurality of HDPE connectors are divided into odd-numbered rows and even-numbered rows, with the plurality of first HDPE connectors in the odd-numbered rows and the plurality of second HDPE connectors in the even-numbered rows arranged alternately.

[0015] Compared with the prior art, the advantages of the present invention are as follows: This application uses a hollow grid-like cell wall constructed by sewing bamboo strips together. Compared with traditional polymer cell walls, this structure is lightweight and high-strength, and creates a three-dimensional interlocking interface and horizontal drainage channels for the cell wall, solving the problems of weak interface friction and poor drainage function of polymer cell walls. The flexible composite strip that makes up the geocell wall is a multi-layer composite structure with an asymmetric orthogonal composite design with a dense outer layer that is circumferentially stressed and a sparse inner layer that is vertically supported. Compared with isotropic polymer geocell walls, it can achieve targeted reinforcement in the most critical circumferential tensile performance of geocells, thereby improving bearing strength, reliability and service life. Meanwhile, this type of geocell based on bamboo strips also has the advantages of flexibility and foldability of polymer geocells, making it convenient for transportation and on-site installation. This application uses renewable bamboo to replace polymer materials, resulting in a low carbon footprint throughout its entire life cycle. The pores in the cell walls provide conditions for plant roots to pass through, supporting ecological slope protection. The product can be naturally degraded after it is scrapped, realizing environmental protection throughout the entire process from green materials to green applications and green disposal. It also drives economic development in areas rich in bamboo resources but with underdeveloped economies, and has extremely high application value. Attached Figure Description

[0016] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the invention will now be described by way of example and with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the bamboo geocell in its unfolded state as shown in this invention; Figure 2 This is a schematic diagram of the compressed and folded state of the bamboo geocell shown in this invention; Figure 3 This is a schematic diagram of the structure of the cell wall shown in this invention; Figure 4 This is an exploded view of the cell wall shown in this invention; Figure 5 This is a schematic diagram of the structure of the middle bamboo strip shown in this invention; Figure 6 This is a schematic diagram of the structure of the outer bamboo strips shown in this invention; Figure 7 This is a schematic diagram of the adhesion and extension of the outer bamboo strip layer as shown in this invention; Figure 8(a) is a schematic diagram of the extension of the middle bamboo strip to form a roll material according to the present invention; Figure 8(b) is a schematic diagram of the outer bamboo strips extended to form a roll material according to the present invention; Figure 9 This is a schematic diagram of a flexible composite strip formed by combining the middle bamboo strip and two outer bamboo strips as shown in this invention; Figure 10 This is a schematic diagram of the two cell walls connected by nodes as shown in this invention; Figure 11 This is a schematic diagram of the structure at the node shown in this invention; Figure 12 This is a partially enlarged schematic diagram of the cell wall shown in this invention; Figure 13 This is a schematic diagram showing multiple cell walls connected by nodes, as illustrated in this invention. Detailed Implementation

[0017] To better understand the technical content of the present invention, specific embodiments are described below in conjunction with the accompanying drawings.

[0018] {Example 1} Combination Figure 1 and Figure 2 As shown, the first aspect of the present invention proposes a technical solution: a bamboo geocell, which consists of multiple cell walls 10 connected to each other at nodes 20 to form a three-dimensional mesh structure, and the three-dimensional mesh structure forms multiple deformable cell spaces 100 for accommodating filler 200.

[0019] Thus, this three-dimensional mesh structure is basically consistent with the existing polymer cell in terms of macroscopic aspects, including flexible cell walls 10 and deformable nodes 20, which can be folded and unfolded, and has high flexibility. On this basis, renewable biomass materials are used, with bamboo replacing plastic, which can reduce carbon emissions, is biodegradable, has no environmental burden after being disposed of, and at the same time promotes the economic development of areas with abundant bamboo resources but underdeveloped economies.

[0020] It should be understood that when this three-dimensional mesh structure is used for slope reinforcement, its lightweight and high-strength characteristics facilitate transportation and construction on steep slopes. The interlocking effect between the cell walls and the fill material can significantly improve the overall anti-sliding stability of the slope. When used for foundation reinforcement, the mesh structure can effectively disperse the upper load and reduce uneven settlement. Its horizontal drainage capacity can accelerate the consolidation process of soft soil foundations and enhance the long-term bearing capacity of the foundation.

[0021] Combination Figure 1 and Figure 2 As shown, multiple parallel cell walls 10 are connected by nodes 20 along a predetermined direction to form geocells of a predetermined size. Adjacent cell walls 10 are separated by multiple nodes 20 to form multiple deformable cell spaces 100, constituting a three-dimensional mesh structure.

[0022] Furthermore, in combination Figure 13 As shown, multiple nodes 20 are divided into odd-numbered rows and even-numbered rows.

[0023] Specifically, taking a geocell consisting of n cells 10 as an example, the first cell is n1, the second is n2, and so on up to nn. The nodes 20 connecting n1-n2, n3-n4, n5-n6, etc. are all odd-numbered nodes, while the nodes 20 connecting n2-n3, n4-n5, n6-n7, etc. are all even-numbered nodes.

[0024] The arrangement of multiple first nodes 21 in odd-numbered rows and multiple second nodes 22 in even-numbered rows, with the second node 22 located in the middle of two adjacent first nodes 21, allows the deformable cell space 100 to be compressed to fit the cell wall 10 or expanded to fill the space of filler 200, forming a honeycomb-like, tightly arranged set of multiple cells after expansion.

[0025] In an optional embodiment, the distance between two adjacent nodes 20 is the welding distance. Different welding distances can be selected according to different application scenarios. For example, for roadbed reinforcement and prevention of uneven settlement of roadbed, a welding distance of no more than 400 mm can be used. For example, for slope protection, a welding distance of no more than 400 mm can be used, and for wind and sand protection, a welding distance of no more than 600 mm can be used.

[0026] Node 20 is configured to allow the two connected cell walls 10 to bend when the deformable cell space 100 is deformed, and to give the two cell walls 10 a tensile strength at node 20.

[0027] In an alternative embodiment, node 20 may also employ other snap-fit ​​structures to connect the two cell walls 10 together.

[0028] The snap-fit ​​structure includes a first part and a second part, which are fixed together by adhesive, snap / fastening, or threaded connection. Each part can be flexible or rigid.

[0029] Furthermore, the first and second parts of the snap-fit ​​structure completely cover the height of the cell wall 10, and are connected to each other or to the cell wall 10 itself at least above and below the cell wall 10, and the connection meets the designed tensile strength.

[0030] Specifically, when the first and second parts of the snap-fit ​​structure are rigid structures, in order not to affect the unfolding and folding of the cell, the width of the snap-fit ​​structure should be as small as possible, forming a narrow and long strip. The two parts can be connected together by snapping and bolts, etc. The pressing action of the first and second parts is used to connect the two cell walls 10 together and form a node.

[0031] Specifically, when the first and second parts of the snap-fit ​​structure are flexible, the width of the snap-fit ​​structure can be larger, and it can also be achieved by adhesive bonding other than snap-fit ​​or threaded connection.

[0032] In a preferred embodiment, both the first node 21 and the second node 22 are fixed to the flexible composite strip by ultrasonic welding using HDPE connectors.

[0033] Specifically, at the locations where HDPE connectors need to be installed, amino resin is coated on the outer wall of the cell wall 10, and then the HDPE connectors are fixed to the outer walls of the two cell walls 10 by ultrasonic welding.

[0034] Combination Figure 11 As shown, the first cell wall n1 and the second cell wall n2 are connected together by HDPE connecting buckles. Part of the HDPE connecting buckle is connected to the first cell wall n1 and the other part is connected to the second cell wall n2. The first cell wall n1 and the second cell wall n2 are connected together by their own material strength, and the tensile strength is satisfied.

[0035] Thus, when the cells are unfolded, the staggered node design ensures that all cell units expand uniformly and synchronously, forming a regular and stable honeycomb structure, thereby providing consistent and reliable lateral restraint. At the same time, when the deformable cell space 100 is compressed and stored, this layout allows the cell walls 10 to fold and fit together in an orderly manner, greatly reducing the storage volume and facilitating transportation and storage.

[0036] In other embodiments, other means can be used to achieve the connection between the two cell walls 10. The nodes need to meet the requirements of flexibility and tensile strength, that is, to allow the cell wall 10 to deform, fold and unfold, and also to meet a certain tensile strength so that it will not crack at the nodes.

[0037] Furthermore, the cell wall 10 is a flexible composite strip woven from bamboo strips, and the composite strip is configured with pores 101 distributed in a dot matrix to form a hollow grid structure, so that the cell wall 10 forms a non-sealed network plane on a macroscopic level, allowing the filler 200 to be embedded and water to flow through the deformable cell space 100, and the deformable cell space 100 is configured to allow compression to fit the cell wall 10 or expansion to accommodate the filler 200.

[0038] Obviously, compared with traditional polymer cells, the bamboo strip weaving structure can form a more three-dimensional cell wall 10. In particular, the surface of the cell wall 10 has a raised structure and a porous structure, which has excellent interface and drainage properties.

[0039] Specifically, the raised structure and pore arrangement on the surface of the geocell wall 10 allow for partial embedding of the filler particles, forming an interlocking effect. This greatly enhances the interfacial friction and integrity between the geocell and the filler 200. This interlocking effect can more effectively limit the lateral displacement and slippage of the filler, especially for coarse-grained materials and sandy soil. Moreover, the entire surface of the geocell wall 10 is covered with pores, providing excellent horizontal drainage channels, which is beneficial for foundation consolidation and reduces engineering risks caused by poor drainage. In addition, the aforementioned pores also provide the possibility for the roots of vegetation to pass through later, enhancing the ecological slope protection effect. At the same time, it also makes the geocell lighter, less expensive, and more flexible.

[0040] Combination Figure 3 and Figure 4 As shown, the flexible composite strip includes at least three layers of bamboo strips: a first bamboo strip layer in the middle layer and a second and third bamboo strip layers on both sides of the middle layer. The adjacent bamboo strip layers are fixed to each other by an adhesive layer 12.

[0041] Each layer of bamboo strips is formed by stitching multiple bamboo strips together in a direction perpendicular to their grain, creating a gap δ between adjacent bamboo strips. Furthermore, in a direction perpendicular to the bamboo strip layers, the bamboo strips of the first bamboo strip layer form a predetermined angle with the bamboo strips of the second and third bamboo strip layers.

[0042] Preferably, the bamboo strips in the first bamboo strip layer have their grain directions orthogonal to those in the second and third bamboo strip layers.

[0043] Thus, compared to isotropic polymer cell walls, orthogonal composites allow high-strength bamboo fibers to be strategically arranged in the circumferential direction where they bear the main tensile stress, thereby achieving superior mechanical properties in key directions with less material. This advantage is something that homogeneous HDPE materials cannot achieve.

[0044] Furthermore, the orthogonal composite structure effectively blocks and disperses cracks. Even if a single bamboo strip breaks, the crack is unlikely to propagate across the orthogonal layer, thus localizing the damage. In contrast, ordinary polymer geocells risk rapid loss of overall function due to localized damage, while bamboo geocells offer higher safety and long-term service performance.

[0045] In the geocell unfolded state, the bamboo strips in the second and third bamboo strip layers extend circumferentially along the deformable geocell space 100 to provide circumferential tensile strength, while the bamboo strips in the first bamboo strip layer extend vertically along the deformable geocell space 100 to provide vertical support for the second and third bamboo strip layers.

[0046] In this way, the tightly arranged outer bamboo strips (the bamboo strips in the second and third bamboo strip layers) provide maximum circumferential tensile strength, giving the geocell excellent lateral restraint. Meanwhile, the relatively sparse inner bamboo strips provide necessary vertical support and prevent the outer layer from becoming unstable, while saving materials, reducing weight, and retaining larger horizontal drainage channels, which is conducive to achieving a balance between mechanical properties and drainage function.

[0047] Furthermore, within the bamboo strip layer, predetermined gaps δ are formed between the bamboo strips through stitching, creating a grid structure. The size of the gaps δ is determined based on the characteristic particle size of the filler 200. Design a system that satisfies the following relationship: δ≤(1 / 2~1 / 3) × ,in It is the particle size corresponding to 85% by weight in the particle distribution curve of filler 200.

[0048] Thus, by scientifically designing according to the anti-filtration principle in soil mechanics, it can be ensured that the vast majority of filler particles are effectively confined within the cells, preventing fine particles from escaping through the gaps and causing soil erosion, while allowing water to pass freely, thereby enabling the geocell to meet the dual requirements of reinforcement and drainage.

[0049] In an optional embodiment, the gap δ = 1~5mm. If the gap δ is too small (<1mm), the bamboo strip layer will resemble a dense bamboo board, resulting in decreased flexibility, weakened drainage capacity, increased material usage and weight per unit area, and higher costs. If the gap δ is too large (>5mm), it may lead to continuous loss of fine-particle filler, causing foundation voids, severely weakening the reinforcement effect, and preventing the cell and filler from forming a cohesive whole.

[0050] Specifically, in combination Figure 12 As shown, in the first bamboo strip layer, the average gap δ1 between the bamboo strips is greater than the average gap δ2 between the bamboo strips in the second and third bamboo strip layers, making the bamboo strips in the second and third bamboo strip layers more tightly arranged than those in the first bamboo strip layer, thereby improving the circumferential tensile strength.

[0051] Combination Figure 5 As shown, the first bamboo strip layer (middle bamboo strip 11) is woven from multiple parallel first bamboo strips 111 through a first seam 112. The first strip gap 113 is formed between adjacent first bamboo strips 111 through the first seam 112. The first bamboo strips 111 are arranged in a vertical direction.

[0052] Combination Figure 6 As shown, the second bamboo strip layer (outer bamboo strip 13) is woven from multiple parallel second bamboo strips 131 through a second seam 132. A second strip-shaped gap 133 is formed between adjacent second bamboo strips 131 through the second seam 132. The second bamboo strips 131 are arranged in a horizontal direction.

[0053] Specifically, such as Figure 5 and Figure 6 As shown, the first bamboo strip layer has a first strip gap 113 distributed along a first direction, and the second bamboo strip layer and the third bamboo strip layer have a second strip gap 133 distributed along a second direction. The first direction is along the length direction of the first bamboo strip 111, and the second direction is along the length direction of the second bamboo strip 131.

[0054] Therefore, the flexible composite strip material formed by the first bamboo strip layer, the second bamboo strip layer and the third bamboo strip layer has pores 101 distributed in a dot matrix pattern formed by the overlapping areas of the first strip gap 113 and the second strip gap 133. The pores 101 are used to allow water or plant roots in the deformable cell space 100 to pass through, and to increase the bonding force with the filler 200.

[0055] In the above embodiments, the bamboo strips are made from the outer green part of the bamboo wall. The green part has high fiber density, good toughness, and significantly better tensile strength than the yellow part; the green part has high cellulose content and moderate lignin content, giving it good flexibility and bending resistance.

[0056] Optionally, the bamboo strips have a thickness of 1.2±0.3mm, a width of 15±3mm, and a length of 2~5m.

[0057] If the bamboo strips are too thin, they will become brittle; if they are too thick, their flexibility will decrease. If the bamboo strips are too wide, they will be difficult to bend; if they are too narrow, their structure will be loose.

[0058] Specifically, the length of the bamboo strips is determined by the length of the bamboo nodes to ensure the continuity of the strips, reduce seams, and improve overall strength.

[0059] Furthermore, the tensile strength of the aforementioned bamboo strips is not less than 180 MPa, the elastic modulus is not less than 15 GPa, and the elongation at break is 1.5~3.0%.

[0060] High tensile strength is the foundation for the cell wall to withstand circumferential tensile stress. The tensile strength of bamboo strips meets the requirements. At the same time, the high modulus of bamboo strips can ensure that the cell deforms little under load and provide sufficient lateral constraint stiffness. Moreover, bamboo strips also have a certain degree of extensibility, which can avoid brittle fracture and release stress through small deformation when the soil deforms.

[0061] As mentioned above, the special properties of bamboo strips are the material basis for the contradictory properties of high strength and flexibility achieved by the cell wall 10. In addition, the flexibility of bamboo strips allows them to bend 180° around a 20mm diameter round rod without cracking. This property ensures good adhesion when curled during manufacturing and transportation, and when laid on uneven foundations.

[0062] Furthermore, the stitch spacing is 30~80mm, and the stitches can be 10 to 20 count hemp thread or ordinary nylon thread with a linear density between 200 and 500 denier.

[0063] It is important to understand that the middle bamboo strip 11 and the two outer bamboo strips 13 are bonded together primarily by resin. The role of the sewing thread is only to connect the strips and maintain the spacing between them for better control during bonding. Therefore, considering cost, ordinary hemp thread can be preferred for the sewing thread.

[0064] The strength of the sutures must meet the requirements for temporary connection: by selecting ordinary hemp thread with appropriate linear density and strength (such as 10-20 count hemp thread), it is ensured that the strips can be stably connected and the spacing maintained before the amino resin cures. After the resin bonding forms strength, the stress on the sutures is further weakened.

[0065] Furthermore, the breaking strength of a single strand of ordinary hemp thread ranges from 2.5 to 9 N. For example, a single strand of 10-count hemp thread has a breaking strength of approximately 2.5 N; a single strand of 20-count hemp thread can reach a breaking strength of approximately 9 N.

[0066] Furthermore, the stitch spacing should be maintained at 30-80mm to ensure precise positioning between the bamboo strips and create favorable conditions for resin bonding. The preferred stitch spacing is approximately 50mm.

[0067] If the spacing between the seams is too small (e.g., <30mm), the bamboo strips will be damaged due to too many puncture points, and the strips will become hard and less flexible, failing to meet the requirements for use in geocells. If the spacing is too large (e.g., >80mm), the bamboo strips will be insufficiently constrained, and the bamboo strips will easily flip, twist, or come out of the seams when under stress, resulting in uneven stress distribution and reduced load-bearing capacity, thus reducing the strength of the geocell.

[0068] Furthermore, the adhesive layer 12 includes an amino resin adhesive layer.

[0069] Amino resin is a water-soluble resin with excellent adhesive properties, effectively bonding bamboo together without hardening. This maintains the flexibility of the bamboo strips, allowing for controlled expansion of the geocell area. The bonding strength of amino resin is greater than the tensile strength of bamboo strips, its flexural modulus matches that of bamboo strips (typically 8 GPa to 12 GPa), and its toughness is close to that of bamboo strips (elongation at break 1.5% to 2.5%).

[0070] In this way, the mechanical properties of the bamboo strips are matched, allowing the flexible composite strip formed by bonding multiple layers of bamboo strips to maintain overall flexibility. This is the key to the geocell's ability to be rolled up for transport and adapt to uneven foundations.

[0071] When forming a flexible composite strip, the adhesive layer 12 is set to form a uniform thin layer of amino resin between two adjacent bamboo strip layers under a preset pressure of 0.4~0.6MPa, so that the two adjacent bamboo strip layers form mechanical interlocking and chemical bonding.

[0072] In an optional embodiment, a lower pressure limit of 0.4 MPa ensures that excess resin is extruded to form a uniform thin layer and that the resin fully impregnates the bamboo fibers, forming strong mechanical interlocking and chemical bonding. An upper pressure limit of 0.6 MPa prevents excessive pressure from crushing the bamboo strips' structure, ensuring that their mechanical properties are not compromised. Curing under this pressure achieves optimal interlayer bonding while preserving overall flexibility.

[0073] It should be noted that the amino resin thin layer is only coated on the surface of the bamboo strips. After the flexible composite strip is formed, the amino resin thin layer will not cause blockage of the pores 101.

[0074] {Example 2} Combination Figures 7 to 13 As shown, the second aspect of the present invention proposes a technical solution, such as the manufacturing method of the bamboo geocell described above, comprising the following steps: Step S1: Split the bamboo into single radial bamboo strips of predetermined size, and then treat them with anti-corrosion, anti-insect and drying methods for later use. Step S2: Arrange the bamboo strips prepared in step S1 in parallel and weave them with sewing thread to form a bamboo strip strip for later use. The gap between adjacent bamboo strips is controlled at 1~5mm, and the spacing of the sewing thread is controlled at 30~80mm. Step S3: Cut the bamboo strips prepared in step S2 into strips with a width equal to the height of the cell wall 10 along the direction parallel to the weaving line, forming the middle bamboo strip 11. Cut the bamboo strips prepared in step S2 into strips with a width equal to the height of the cell wall 10 along the direction parallel to the bamboo strips, forming the outer bamboo strip 13. Step S4: Apply amino resin adhesive to the bonding surfaces of the middle bamboo strip 11 and the two outer bamboo strips 13, so that the two outer bamboo strips 13 sandwich the middle bamboo strip 11, and pressurize and cure under a pressure of 0.4~0.6MPa to form a flexible composite strip material with the same height as the cell wall 10. Step S5: Two adjacent cell walls 10 are connected to each other by HDPE fasteners and ultrasonic welding to form a three-dimensional mesh structure, forming a deformable cell space 100 between multiple cell walls 10. In step S5, the multiple HDPE connectors are divided into odd rows and even rows, with the multiple first HDPE connectors in the odd rows and the multiple second HDPE connectors in the even rows arranged alternately.

[0075] In step S3, combined Figure 7As shown, during the production of the outer bamboo strip 13, the bamboo strips formed by sewing are cut to a predetermined height, and then every two bamboo strips are glued together end to end. That is, the first bamboo strip 13a and the second bamboo strip 13b are glued together through an overlap area 13c of a certain width to form a longer strip structure, and finally rolled into a tube for later use.

[0076] The middle bamboo strip 11 and the outer bamboo strip 13 are wound into a cylindrical shape, as shown in Figures 8(a) and 8(b) respectively.

[0077] Among them, for the outer bamboo strip 13, the length of a single bamboo strip is related to the bamboo strip. By bonding multiple bamboo strips, the outer bamboo strip 13 reaches the predetermined length, and the length L of the overlapping area 13c is not less than the height of the cell wall.

[0078] In a specific embodiment: 1. Weaving radial bamboo strip curtains (referred to as radial curtains): Using a bamboo strip production machine, moso bamboo is split into single radial bamboo strips approximately 15mm wide, 1.2mm thick, and 2m to 5m long. These strips are then treated for preservation, insect prevention, and drying before use. A radial curtain weaving machine is used to weave the bamboo strips in parallel to form a continuous radial curtain. Hemp thread is used for weaving, with a spacing of 50mm. Depending on the project requirements, the internode spacing between parallel bamboo strips can be 2mm to 5mm. The radial curtain is then rolled into a roll for later use.

[0079] 2. Production of inner layer base bamboo strips (middle bamboo strip 11): According to the height of the lattice wall (50mm, 100mm, 150mm, 200mm, 250mm, 300mm can be used), cut the radial curtain roll into bamboo strips with a width equal to the height of the lattice wall along the direction parallel to the weaving line, and roll them into a tube for later use.

[0080] 3. Construction of the outer layer base bamboo strips (outer layer bamboo strip 13): Based on the height of the grid wall (50mm, 100mm, 150mm, 200mm, 250mm, 300mm are acceptable), gradually unfold the radial curtain roll. Cut the radial curtain into sheets with a width equal to the height of the grid wall, parallel to the bamboo strip direction. Then, connect the front and rear sheets along the bamboo strip direction to form a continuous bamboo strip and roll it up for later use. The overlap length of the front and rear sheets should not be less than the height of the grid wall, and the overlap method is to use amino resin adhesive.

[0081] 4. Fabrication of flexible composite strip: Two outer base bamboo strips are sandwiched between an inner base bamboo strip (middle bamboo strip 11) and bonded with amino resin. The strip is then cured under pressure of 0.4~0.6MPa to form a flexible composite strip. The width of the flexible composite strip is equal to the height of the cell wall 10.

[0082] 5. Geocell fabrication: First, determine the welding distance of the geocell (i.e., the distance between two adjacent nodes); then combine... Figure 10 As shown, the first and second flexible composite strips are fixed at each node by ultrasonic welding using high-strength HDPE connectors with equal welding spacing; the third and second flexible composite strips are fixed at each node by ultrasonic welding using high-strength HDPE connectors with equal welding spacing, and so on, until the appropriate length is reached.

[0083] After the first cell wall and the adjacent second cell wall are connected by node 20, a mesh structure is formed between the parallel cell walls 10.

[0084] Combination Figure 13 As shown, multiple nodes 20 are divided into odd-numbered rows and even-numbered rows.

[0085] Specifically, taking a geocell consisting of n cells 10 as an example, the first cell is n1, the second is n2, and so on up to nn. The nodes 20 connecting n1-n2, n3-n4, n5-n6, etc. are all odd-numbered nodes, while the nodes 20 connecting n2-n3, n4-n5, n6-n7, etc. are all even-numbered nodes.

[0086] The arrangement of multiple first nodes 21 in odd-numbered rows and multiple second nodes 22 in even-numbered rows is staggered, with the second node 22 located between two adjacent first nodes 21, so as to facilitate the deployment of geocells during use.

[0087] Where n is the total amount of flexible composite strips used in this geocell. The n flexible composite strips are of equal length, and their lengths and n are determined by specific construction requirements.

[0088] 6. Geocell Installation: The installation method for geocells is the same as that for polymer geocells, and the function of geocell layers in foundation reinforcement or slope reinforcement is also the same. The collected geocells are unfolded on site, and filler is placed into the unfolded cells to form a geocell layer. Multiple geocell layers can be installed according to project needs; the installation area and location depend on the project parameters.

[0089] As described above, each flexible composite strip is produced in a standardized manner in the factory, which can ensure stable and uniform quality. At the same time, it can be flexibly spliced ​​into cell walls of any length according to site needs, adapting to projects of different scales. In addition, if there is local damage, only the damaged strip segment can be replaced, without discarding the entire cell, which greatly reduces the maintenance cost throughout the entire life cycle.

[0090] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A bamboo geocell, characterized in that, It includes a three-dimensional mesh structure formed by multiple cell walls (10) interconnected at nodes (20), the three-dimensional mesh structure forming multiple deformable cell spaces (100) for accommodating filler (200). The cell wall (10) is a flexible composite strip woven from bamboo strips, and the composite strip is configured with pores (101) distributed in a dot matrix to form a hollow grid structure, so that the cell wall (10) forms a network-like plane that is not sealed on a macroscopic scale and allows the filler (200) to be embedded and water to flow through the deformable cell space (100). The deformable cell space (100) is configured to allow compression to fit the cell wall (10) or expansion to accommodate the filler (200). The flexible composite strip includes at least three layers of bamboo strips, a first bamboo strip layer in the middle layer, and a second and third bamboo strip layer on both sides of the middle layer. The adjacent bamboo strip layers are fixed to each other by an adhesive layer (12). Each layer of bamboo strips is formed by stitching multiple bamboo strips together in a direction perpendicular to its texture, so that there is a gap δ between the adjacent bamboo strips. In the direction perpendicular to the bamboo strip layer, the bamboo strips of the first bamboo strip layer and the bamboo strips of the second and third bamboo strip layers form a predetermined angle. In the geocell unfolded state, the bamboo strips in the second and third bamboo strip layers extend circumferentially along the deformable geocell space (100) to provide circumferential tensile strength, and the bamboo strips in the first bamboo strip layer extend vertically along the deformable geocell space (100) to provide vertical support for the second and third bamboo strip layers.

2. The bamboo geocell according to claim 1, characterized in that, In the bamboo strip layer, a predetermined gap δ is formed between the bamboo strips through the seam, so that the bamboo strip layer forms a grid structure. The size of the gap δ is based on the characteristic particle size of the filler (200). Design a system that satisfies the following relationship: δ≤(1 / 2~1 / 3) × ,in It is the particle size corresponding to 85% by weight in the particle distribution curve of filler (200).

3. The bamboo geocell according to claim 1, characterized in that, The gap δ = 1~5mm; In the first bamboo strip layer, the average gap δ1 between the bamboo strips is greater than the average gap δ2 between the bamboo strips in the second and third bamboo strip layers, making the bamboo strips in the second and third bamboo strip layers more tightly arranged than those in the first bamboo strip layer, thereby improving the circumferential tensile strength.

4. The bamboo geocell according to any one of claims 1-3, characterized in that, The first bamboo strip layer has a first strip gap distributed along a first direction, and the second and third bamboo strip layers have a second strip gap distributed along a second direction. The flexible composite strip material formed by the first, second and third bamboo strip layers has pores (101) distributed in a dot matrix by overlapping areas of the first and second strip gaps. The pores (101) are used to allow water or plant roots in the deformable cell space (100) to pass through and to increase the bonding force with the filler (200).

5. The bamboo geocell according to any one of claims 1-3, characterized in that, The bamboo strips are made from the outer green part of the bamboo wall; and / or, the thickness of the bamboo strips is 1.2±0.3mm, the width is 15±3mm, the length is 2~5m, the tensile strength of the bamboo strips is not less than 180MPa, the elastic modulus is not less than 15GPa, and the elongation at break is 1.5~3.0%.

6. The bamboo geocell according to claim 1, characterized in that, The bamboo strips in the first bamboo strip layer have texture directions that are orthogonal to those in the second and third bamboo strip layers.

7. The bamboo geocell according to claim 1, characterized in that, The stitch spacing of the suture is 30-80mm, and the suture is 10-20 count hemp thread or nylon fiber with a linear density between 200 and 500 denier.

8. The bamboo geocell according to claim 1, characterized in that, The adhesive layer (12) includes an amino resin adhesive layer. The bonding strength of the amino resin adhesive layer is greater than the tensile strength of the bamboo strip, and the bending modulus is 8~12GPa. It matches the mechanical properties of the bamboo strip, so that the flexible composite strip formed by the adhesive layer of multiple bamboo strips maintains the overall flexibility. The adhesive layer (12) is configured to form an amino resin thin layer between two adjacent bamboo strip layers under a preset pressure of 0.4~0.6MPa, so that the two adjacent bamboo strip layers form mechanical interlocking and chemical bonding.

9. The bamboo geocell according to claim 1, characterized in that, Multiple parallel cell walls (10) are connected by nodes (20) along a predetermined direction to form geocells of a predetermined size. Adjacent cell walls (10) are separated by multiple nodes (20) to form multiple deformable cell spaces (100), forming a three-dimensional mesh structure. Among them, the multiple nodes (20) are divided into odd rows and even rows, and the multiple first nodes (21) in the odd rows and the multiple second nodes (22) in the even rows are arranged alternately, so that the deformable cell space (100) can be compressed to fit against the cell wall (10) or expanded to the space that can be filled with filler (200). The node (20) is configured to allow the two connected cell walls (10) to bend when the deformable cell space (100) is deformed, and to give the two cell walls (10) a tensile strength at the node (20).

10. The method for manufacturing a bamboo geocell according to any one of claims 1-9, characterized in that, Includes the following steps: Step S1: Split the bamboo into single radial bamboo strips of predetermined size, and then treat them with anti-corrosion, anti-insect and drying methods for later use. Step S2: Arrange the bamboo strips prepared in step S1 in parallel and weave them with sewing thread to form a bamboo strip strip for later use. The gap between adjacent bamboo strips is controlled at 1~5mm, and the spacing of the sewing thread is controlled at 30~80mm. Step S3: Cut the bamboo strips prepared in step S2 into strips with a width equal to the height of the grid wall (10) along the direction parallel to the weaving line to form the middle bamboo strip (11). Cut the bamboo strips prepared in step S2 into strips with a width equal to the height of the grid wall (10) along the direction parallel to the bamboo strip to form the outer bamboo strip (13). Step S4: Apply amino resin adhesive to the bonding surfaces of the middle bamboo strip (11) and the two outer bamboo strips (13) so that the two outer bamboo strips (13) sandwich the middle bamboo strip (11) and pressurize it under a pressure of 0.4~0.6MPa to form a flexible composite strip with the same height as the cell wall (10); Step S5: Two adjacent cell walls (10) are connected to each other by HDPE fasteners and ultrasonic welding to form a three-dimensional mesh structure, forming a deformable cell space (100) between multiple cell walls (10). In step S5, the plurality of HDPE connectors are divided into odd-numbered rows and even-numbered rows, with the plurality of first HDPE connectors in the odd-numbered rows and the plurality of second HDPE connectors in the even-numbered rows arranged alternately.

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