Foam-filled retaining walls and their construction methods

Abstract

This invention provides a foam-filled retaining wall and its construction method, relating to the field of filling technology for goaf areas in underground mines. The foam-filled retaining wall comprises two prefabricated foam layers spaced apart, with a bridging structure between the two layers. A reinforcing mesh is installed on the bridging structure, and concrete and polyurethane foam are poured between the two prefabricated foam layers as filler. Based on the technical solution of this invention, the foam-filled retaining wall can improve its strength and water filtration performance, increase its construction efficiency, reduce its construction cost, and enhance its construction safety.

Description

Technical Field

[0001] This invention relates to the field of filling technology for goaf areas in underground mines, and particularly to a foam-filled retaining wall and its construction method. Background Technology

[0002] Backfill retaining walls are a common engineering structure used in backfilling operations in underground mine goaf areas. Before backfilling, retaining walls should be constructed in stable sections of the surrounding rock along the goaf access route. The construction of these retaining walls is crucial for the successful completion of the backfilling operation. Currently, backfill retaining walls used in China can be mainly classified into the following types: gravity retaining walls, lightweight retaining walls, and composite retaining walls combining gravity and lightweight elements. Gravity retaining walls can be further divided into hollow brick retaining walls, red brick retaining walls, and concrete retaining walls, etc.; lightweight retaining walls can be further divided into wooden retaining walls, wire rope retaining walls, etc.; composite retaining walls are a combination of gravity retaining walls and lightweight retaining walls. Among these, concrete retaining walls and wooden retaining walls are the most commonly used.

[0003] Traditional retaining walls and their construction methods have significant drawbacks. For example, concrete retaining walls have relatively poor flexural strength, making them prone to displacement and deformation when subjected to the lateral pressure of the filling grout. If this exceeds the concrete retaining wall's bearing capacity, it may collapse, causing the filling material (such as tailings) to overflow. This not only affects the filling effect but may also threaten the safety of surrounding tunnels and workers. Therefore, to prevent displacement and deformation, thicker retaining walls are often chosen during construction. However, this increases the amount of concrete used and the demand for auxiliary materials, significantly increasing construction costs. Furthermore, thicker retaining walls may reduce filtration efficiency and affect the dehydration and curing process of the filling material. During construction, ensuring the stability and strength of the retaining wall requires complex formwork construction and rebar fixing, which are often time-consuming and labor-intensive, reducing construction efficiency and impacting company revenue. In addition, the large-scale use of concrete as a retaining wall material increases the mining and processing of raw materials, and the waste generated during construction may also burden the environment.

[0004] While wooden retaining walls can provide some support, their construction and processing are complex, requiring high-quality timber, which increases costs. Furthermore, wood is prone to rotting in damp underground environments, reducing the retaining wall's durability. The construction of wooden retaining walls requires extensive on-site work, such as manually erecting wooden stakes, which not only increases the workload but also places high demands on the physical strength and skills of the workers. Both concrete and wooden retaining walls carry inherent safety risks during construction. Concrete retaining walls may experience accidents during pouring and curing, while wooden retaining walls may collapse or cause injuries due to improper handling during erection.

[0005] Therefore, it is necessary to design a foam-filled retaining wall and its construction method, which can improve the strength and water filtration performance of the foam-filled retaining wall, improve the construction efficiency of the foam-filled retaining wall, reduce the construction cost of the foam-filled retaining wall, and improve the construction safety of the foam-filled retaining wall. Summary of the Invention

[0006] To address the problems in the prior art, this application proposes a foam-filled retaining wall and its construction method, which can improve the strength and water filtration performance of the foam-filled retaining wall, increase the construction efficiency of the foam-filled retaining wall, reduce the construction cost of the foam-filled retaining wall, and improve the construction safety of the foam-filled retaining wall.

[0007] One aspect of the present invention provides a foam-filled retaining wall, the foam-filled retaining wall comprising two prefabricated foam layers spaced apart, a bridge spanning between the two prefabricated foam layers, a steel mesh installed on the bridge, and concrete and polyurethane foam filling material poured between the two prefabricated foam layers.

[0008] As a further improvement to the above technical solution:

[0009] Furthermore, in the aforementioned foam-filled retaining wall, the bridge is provided with positioning grooves, and the reinforcing bars of the steel mesh are positioned and placed in the positioning grooves.

[0010] Furthermore, in the aforementioned foam-filled retaining wall, the prefabricated foam layer comprises multiple prefabricated foam blocks, the edges of which are serrated, and adjacent prefabricated foam blocks are joined together through their serrated edges.

[0011] Furthermore, the aforementioned foam-filled retaining wall has water-filtering holes formed on the prefabricated foam layer.

[0012] Furthermore, in the aforementioned foam-filled retaining wall, an observation window is installed on the prefabricated foam layer for observing the filler.

[0013] In the aforementioned foam-filled retaining wall, the prefabricated foam layer is expanded polystyrene foam.

[0014] Another aspect of the present invention provides a method for constructing a foam-filled retaining wall, applicable to the aforementioned foam-filled retaining wall, the method comprising the steps of:

[0015] Choose the installation location for the retaining wall;

[0016] Multiple prefabricated foam blocks are spliced ​​together by their serrated edges to form two spaced prefabricated foam layers.

[0017] The reinforcing bars of the steel mesh are inserted into the positioning slots of the bridge.

[0018] Concrete and polyurethane foam filler are poured between two layers of precast foam.

[0019] As a further improvement to the above technical solution:

[0020] The above-described method for constructing a foam-filled retaining wall further includes the following steps:

[0021] Insert a vibrating stick into the filling material and use vibration to expel the air from the filling material.

[0022] The above-mentioned technical features can be combined in various suitable ways or replaced by equivalent technical features, as long as the purpose of the present invention can be achieved.

[0023] The present invention provides a foam-filled retaining wall and its construction method, which, compared with the prior art, has at least the following beneficial effects: When constructing the foam-filled retaining wall, firstly, the installation location of the retaining wall is selected, then two layers of prefabricated foam are installed at intervals, then the reinforcing bars of the steel mesh are inserted into the positioning groove of the bridging, and finally, concrete and polyurethane foam filling material are poured between the two layers of prefabricated foam. In this foam-filled retaining wall, the prefabricated foam layer has high shear strength due to its unique material properties, and the two layers of prefabricated foam are connected by bridging, which can effectively prevent the deformation and collapse of the retaining wall. The prefabricated foam layer not only has high strength, but also has a good permeability coefficient, which means that the filling retaining wall constructed by the prefabricated foam layer can better filter water and meet the requirements of filling and dewatering. This is crucial for preventing the loss of filling material and maintaining the stability of underground space.

[0024] Precast foam layers can be prefabricated in the factory and then transported directly to the site for assembly. This construction method greatly simplifies the construction process, shortens the construction period, and improves construction efficiency. The modular design of the foam layer makes construction more flexible and efficient. Construction personnel can quickly adjust the layout and combination of modules according to the specific site conditions, thereby better adapting to different construction environments and needs.

[0025] The material cost of foam layers is relatively low. For example, the price of a 250-type wall module is 70 yuan / square meter, and the price of a 280-type module is 75 yuan / square meter, which is lower than the cost of traditional infill retaining wall materials. This cost advantage not only reduces initial investment but also reduces subsequent maintenance costs. The durability and ease of maintenance of foam layers further reduce overall operating costs. In addition, due to the high strength of foam layers, there is no need to thicken the wall, which further reduces the amount of material used and the cost. Because foam layers can be installed quickly and have a short construction period, the corresponding construction costs are also reduced. Furthermore, the modular design of foam layers reduces the complexity and uncertainty in construction, further reducing any additional costs that may arise during construction.

[0026] The construction process of the foam layer is relatively simple, requiring less skill from construction workers and thus reducing safety risks. Furthermore, the lightweight nature of the foam layer makes handling and installation easier, reducing the labor intensity for workers. The foam layer uses flame-retardant materials, and its fire resistance is further improved after the main structure is assembled. This is significant in preventing underground combustion accidents, ensuring the safety of construction workers and mining operations.

[0027] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0029] The invention will now be described in more detail with reference to embodiments and the accompanying drawings.

[0030] Figure 1 This shows a schematic diagram of the structure of the foam-filled retaining wall provided in an embodiment of the present invention;

[0031] Figure 2 This shows a schematic diagram of the structure of the prefabricated foam layer of the foam-filled retaining wall provided in an embodiment of the present invention;

[0032] Figure 3 This shows a schematic diagram of the steel mesh structure of the foam-filled retaining wall provided in an embodiment of the present invention;

[0033] Figure 4 This shows a schematic diagram of the structure of the prefabricated foam block of the foam-filled retaining wall provided in an embodiment of the present invention;

[0034] Figure 5 This diagram shows the assembly structure of prefabricated foam blocks for a foam-filled retaining wall provided in an embodiment of the present invention.

[0035] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not to scale.

[0036] Explanation of reference numerals in the attached figures:

[0037] 100-Foam-filled retaining wall, 110-Precast foam layer, 111-Precast foam block, 112-Filter hole, 113-Observation window, 120-Bridging, 121-Positioning groove, 130-Reinforcing mesh, 140-Filling material. Detailed Implementation

[0038] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0039] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0041] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0042] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0043] The invention will now be further described with reference to the accompanying drawings.

[0044] This invention provides a foam-filled retaining wall 100, which can improve the strength and water filtration performance of the retaining wall, increase the construction efficiency of the retaining wall, reduce the construction cost of the retaining wall, and improve the construction safety of the retaining wall.

[0045] Please see Figure 1 , Figure 3 and Figure 4 The foam-filled retaining wall 100 provided in this embodiment of the invention includes two prefabricated foam layers 110 spaced apart, a bridge 120 spanning between the two prefabricated foam layers 110, a steel mesh 130 installed on the bridge 120, and a filler 140 of concrete and polyurethane foam poured between the two prefabricated foam layers 110.

[0046] When it is necessary to construct the foam-filled retaining wall 100, first select the installation position of the retaining wall, then install two layers of prefabricated foam layers 110 with intervals, then insert the reinforcing bars of the steel mesh 130 into the positioning groove 121 of the bridge 120, and finally pour concrete and polyurethane foam filler 140 between the two layers of prefabricated foam layers 110.

[0047] In this foam-filled retaining wall 100, traditional retaining walls, due to limitations in materials and structure, have poor shear strength, easily leading to local bending deformation or even collapse and sand runoff. In such cases, the filling slurry may enter adjacent roadways or working faces, seriously affecting normal mine production. However, the precast foam layer 110, due to its unique material properties, has high shear strength. Furthermore, the two precast foam layers 110 are connected by a bridging structure 120, effectively preventing deformation and collapse of the retaining wall. The precast foam layer 110 not only has high strength but also a good permeability coefficient, meaning that the retaining wall constructed with the precast foam layer 110 can better filter water and meet the requirements for filling and dewatering. This is crucial for preventing the loss of filling materials and maintaining the stability of the underground space.

[0048] Traditional infill retaining wall construction is complex and requires significant manpower and time. In contrast, precast foam layers can be prefabricated in a factory and then transported directly to the site for assembly. This construction method greatly simplifies the process, shortens the construction period, and improves efficiency. The modular design of the foam layers makes construction more flexible and efficient. Construction workers can quickly adjust the layout and combination of modules according to the specific site conditions, thus better adapting to different construction environments and needs.

[0049] The material cost of foam layers is relatively low. For example, the price of a 250-type wall module is 70 yuan / square meter, and the price of a 280-type module is 75 yuan / square meter, which is lower than the cost of traditional infill retaining wall materials. This cost advantage not only reduces initial investment but also reduces subsequent maintenance costs. The durability and ease of maintenance of foam layers further reduce overall operating costs. In addition, due to the high strength of foam layers, there is no need to thicken the wall, which further reduces the amount of material used and the cost. Because foam layers can be installed quickly and have a short construction period, the corresponding construction costs are also reduced. Furthermore, the modular design of foam layers reduces the complexity and uncertainty in construction, further reducing any additional costs that may arise during construction.

[0050] The construction process of the foam layer is relatively simple, requiring less skill from construction workers and thus reducing safety risks. Furthermore, the lightweight nature of the foam layer makes handling and installation easier, reducing the labor intensity for workers. The foam layer uses flame-retardant materials, and its fire resistance is further improved after the main structure is assembled. This is significant in preventing underground combustion accidents, ensuring the safety of construction workers and mining operations.

[0051] The foam-filled retaining wall 100 provided in this embodiment of the invention, for details please refer to... Figure 3 and Figure 4The bridge 120 is provided with positioning grooves 121, in which the reinforcing bars of the steel mesh 130 are positioned. In this embodiment, the prefabricated foam layers 110 are all double-sided, with two rows of high-density bridges 120 inside. In addition to reinforcing the connection between the prefabricated foam layers 110, they also serve to fix the reinforcing bars (anchors). After all the prefabricated foam layers 110 are overlapped, the reinforcing bars (anchors) are inserted horizontally and vertically along the positioning grooves 121 on the bridge 120. The positioning grooves 121 position the reinforcing bars of the steel mesh 130, so that the reinforcing bars of the steel mesh 130 are evenly distributed, thereby improving the overall strength of the foam-filled retaining wall 100 provided in this embodiment of the invention.

[0052] In this embodiment, please refer to Figure 2 and Figure 5 The precast foam layer 110 comprises multiple precast foam blocks 111, each with serrated edges. Adjacent precast foam blocks 111 are joined together via their serrated edges. The factory-modularly manufactured precast foam blocks 111 are prefabricated to standard sizes according to design requirements, ensuring consistent and reliable product quality. The modular design also allows for rapid assembly and disassembly, improving construction flexibility. The serrated grooves on the edges of each precast foam block 111 allow for tight interlocking, forming a stable structure. This connection method not only simplifies the construction process but also enhances the overall stability of the retaining wall. If special-sized precast foam blocks 111 are required on-site, workers can use simple tools, such as knives, to quickly cut the foam to meet different size requirements. This flexibility significantly improves the adaptability and efficiency of construction.

[0053] The foam-filled retaining wall 100 provided in this embodiment of the invention, further, please refer to... Figure 1 and Figure 2 The prefabricated foam layer 110 has filter holes 112, which further improve the water permeability of the foam-filled retaining wall 100. An observation window 113 is installed on the prefabricated foam layer 110 for observing the filler 140. The prefabricated foam layer 110 is expanded polystyrene foam. Other materials can also be selected to make the prefabricated foam layer 110 during the design process; for example, graphene can be used as a raw material.

[0054] Expanded polystyrene (EPS) is a lightweight material, but its mechanical strength is relatively low. Graphene, on the other hand, is renowned for its excellent mechanical properties, possessing extremely high Young's modulus and tensile strength, making it one of the strongest known materials. EPS itself does not possess fire resistance and typically requires the addition of flame retardants to improve its fire resistance, usually achieving a Class B rating. The application of graphene in fire-retardant coatings can enhance the fire resistance of the coating; studies have shown that the addition of graphene significantly enhances the fire resistance and thermal stability of fire-retardant coatings. Simultaneously, graphene can also be used in antistatic materials, such as graphene nano-antistatic workbenches, which are made using graphene nanotechnology and possess antistatic properties. EPS, as a plastic foam material, has a relatively low cost and is affordable. Graphene, as a novel high-performance material, has a higher production cost and is relatively more expensive.

[0055] The method for constructing the foam-filled retaining wall 100 according to this embodiment of the invention is applied to the foam-filled retaining wall 100 provided in the above embodiment. The method for constructing the foam-filled retaining wall 100 includes the following steps:

[0056] S10: Select the installation location of the retaining wall.

[0057] S20: Multiple prefabricated foam blocks 111 are spliced ​​together by their serrated edges to form two prefabricated foam layers 110 spaced apart.

[0058] The prefabricated foam blocks 111, manufactured in a modular fashion in the factory, are pre-manufactured to standard dimensions according to design requirements, ensuring consistent and reliable product quality. The modular design also allows for rapid assembly and disassembly, increasing construction flexibility. The serrated grooves on the edges of each prefabricated foam block 111 allow for tight interlocking, forming a stable structure. This connection method not only simplifies the construction process but also enhances the overall stability of the retaining wall. If special-sized prefabricated foam blocks 111 are required on-site, workers can use simple tools, such as knives, to quickly cut the foam to meet different size requirements. This flexibility significantly improves the adaptability and efficiency of construction.

[0059] S30: Insert the reinforcing bars of the steel mesh 130 into the positioning groove 121 of the bridge 120.

[0060] Workers insert reinforcing bars along the positioning grooves 121 on the bridge 120. These reinforcing bars act as a locking mechanism during the filling of concrete and polyurethane foam filler 140, preventing the concrete from shifting during the curing process.

[0061] S40: Concrete and polyurethane foam filler 140 are poured between two precast foam layers 110.

[0062] The combined use of concrete and polyurethane foam not only provides the necessary structural strength for the infill (140), but also improves the insulation and energy-saving effect of the retaining wall by utilizing the lightweight and excellent thermal insulation properties of polyurethane foam. Using polyurethane foam as an infill material not only reduces the weight of the structure, but also has good environmental adaptability, reducing the consumption of natural resources and the generation of waste during construction.

[0063] The method for constructing the foam-filled retaining wall 100 according to an embodiment of the present invention further includes the following steps:

[0064] S50: Insert a vibrating stick into the filler 140 to expel air from the filler 140 through vibration.

[0065] After the concrete and polyurethane foam filler 140 are filled, workers need to use a vibrating rod to continuously insert into the foam concrete to expel the air from the concrete through vibration. After the foam concrete solidifies and takes shape, the foam-filled retaining wall 100 is completed.

[0066] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0067] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A foam-filled retaining wall, characterized in that, The foam-filled retaining wall (100) includes two prefabricated foam layers (110) spaced apart, a bridge (120) spanning between the two prefabricated foam layers (110), a steel mesh (130) installed on the bridge (120), and a filler (140) of concrete and polyurethane foam poured between the two prefabricated foam layers (110). The bridge (120) is provided with a positioning groove (121), and the steel bars of the steel mesh (130) are positioned and placed in the positioning groove (121); The prefabricated foam layer (110) includes multiple prefabricated foam blocks (111), the edges of which are serrated, and adjacent prefabricated foam blocks (111) are spliced ​​together through their serrated edges; The pre-fabricated foam layer (110) has filter holes (112); An observation window (113) is installed on the prefabricated foam layer (110), and the observation window (113) is used to observe the filler (140); The pre-fabricated foam layer (110) is expanded polystyrene foam.

2. A method for constructing a foam-filled retaining wall, characterized in that, Applied to the foam-filled retaining wall (100) described in the preceding claims, the method for constructing the foam-filled retaining wall includes the following steps: Choose the installation location for the retaining wall; Multiple prefabricated foam blocks (111) are spliced ​​together through their serrated edges to form two spaced prefabricated foam layers (110); The reinforcing bars of the steel mesh (130) are inserted into the positioning groove (121) of the bridge (120); Concrete and polyurethane foam filler (140) are poured between two precast foam layers (110).

3. The method for constructing a foam-filled retaining wall according to claim 2, characterized in that, The method for constructing the foam-filled retaining wall also includes the following steps: Use a vibrating stick to insert into the filler (140) to expel the air from the filler (140) by vibration.

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