A wave-absorbing support structure for use in a grouting hole and an evaluation method thereof

Abstract

The application relates to the technical field of tunnel support, in particular to a wave-absorbing support structure for a grouting hole and an evaluation method thereof. The structure comprises surrounding rock, a reinforcing layer, a first wave-absorbing layer and a second wave-absorbing layer. The surrounding rock is provided with a grouting hole. The reinforcing layer is arranged inside the grouting hole. The first wave-absorbing layer is arranged inside the reinforcing layer. The second wave-absorbing layer is arranged inside the first wave-absorbing layer. The reinforcing layer, the first wave-absorbing layer and the second wave-absorbing layer are sequentially arranged from outside to inside in the grouting hole. The application constructs a multilayer composite support structure and relies on the gradient distribution characteristics of the wave impedance of each layer to realize step-by-step reflection and dissipation of disturbance waves. While ensuring the reinforcing efficiency of the support structure and the stability of the interface, the attenuation ability to dynamic disturbance is significantly improved.

Description

Technical Field

[0001] This invention relates to the field of tunnel support technology, and more specifically, to a wave-absorbing support structure for use in grouting holes and its evaluation method. Background Technology

[0002] As underground engineering continues to extend into deeper geological environments with increasingly complex geological conditions, the discontinuous structures within the surrounding rock, such as internal fissures and original structural planes, expand under long-term complex dynamic disturbances. This can easily induce disasters such as rockbursts, seriously threatening the safety and long-term stability of the project. Conventional grouting reinforcement technology has been widely used to improve the integrity of the surrounding rock by filling fissures. However, this technology is mainly designed for static load conditions and has limited ability to control dynamic disturbances. In recent years, to reduce the impact of disturbance waves on the surrounding rock, absorbing grouting methods have emerged, which improve the attenuation effect of disturbance waves by incorporating low wave impedance materials. However, this type of technology still has some shortcomings: on the one hand, the introduction of low wave impedance materials often leads to a significant decrease in the strength of the grouting material, weakening its support performance; on the other hand, single-layer structural designs are prone to significant reflection at the rock-material interface, generating large tensile stresses and causing the cementation interface to detach, affecting the overall structural stability and the attenuation effect of disturbance waves. Summary of the Invention

[0003] The purpose of this invention is to provide a microwave absorbing support structure for grouting holes and its evaluation method, in order to improve the above-mentioned problems. To achieve the above objective, the technical solution adopted by this invention is as follows: On one hand, this application provides a wave-absorbing support structure for use in grouting holes, the structure comprising: surrounding rock, a reinforcing layer, a first wave-absorbing layer and a second wave-absorbing layer, wherein the surrounding rock is provided with grouting holes; the reinforcing layer is disposed inside the grouting holes; the first wave-absorbing layer is disposed inside the reinforcing layer; the second wave-absorbing layer is disposed inside the first wave-absorbing layer, and the reinforcing layer, the first wave-absorbing layer and the second wave-absorbing layer are arranged sequentially from the outside to the inside in the grouting holes.

[0004] On the other hand, this application provides a method for evaluating wave-absorbing support structures within grouting holes, the method comprising: Obtain information on the development of fractures in the surrounding rock of the construction area; The location of the grouting holes is determined based on the information on the development of fractures in the surrounding rock of the construction area; Grouting holes are made according to their locations, and a reinforcement layer, a first wave-absorbing layer, and a second wave-absorbing layer are sequentially arranged in the grouting holes from the outside to the inside to obtain a wave-absorbing support structure. The wave absorption capacity of the wave-absorbing support structure was evaluated, and the evaluation results were obtained.

[0005] The beneficial effects of this invention are as follows: This invention constructs a multi-layer composite support structure by sequentially arranging a reinforcement layer, a first wave-absorbing layer, and a second wave-absorbing layer from the outside to the inside within the grouting hole of the surrounding rock. By relying on the gradient distribution characteristics of the wave impedance of each layer of materials, the invention achieves the stepwise reflection and dissipation of disturbance waves. While ensuring the reinforcement performance and interface stability of the support structure, it significantly improves the attenuation capability of dynamic disturbances.

[0006] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing embodiments of the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0007] 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.

[0008] Figure 1 This is a schematic diagram of the wave-absorbing support structure used in the grouting hole according to an embodiment of the present invention.

[0009] Figure 2 This is an assembly diagram of the second absorbing layer.

[0010] Figure 3 This is a schematic diagram of the trench structure.

[0011] Figure 4 This is a schematic diagram of the propagation path of the disturbance wave through the wave-absorbing support structure used for grouting holes.

[0012] The markings in the diagram are: 1. Surrounding rock; 2. Reinforcement layer; 3. First wave-absorbing layer; 4. Second wave-absorbing layer; 5. Trench. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0014] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. Example 1

[0015] like Figure 1 As shown, this embodiment provides a wave-absorbing support structure for use in grouting holes. The structure includes: surrounding rock 1, a reinforcing layer 2, a first wave-absorbing layer 3, and a second wave-absorbing layer 4. The surrounding rock 1 is provided with grouting holes; the reinforcing layer 2 is disposed inside the grouting holes; the first wave-absorbing layer 3 is disposed inside the reinforcing layer 2; and the second wave-absorbing layer 4 is disposed inside the first wave-absorbing layer 3. The reinforcing layer 2, the first wave-absorbing layer 3, and the second wave-absorbing layer 4 are arranged sequentially from the outside to the inside in the grouting holes. In the prior art, conventional grouting support technology is mainly designed for static loads. Because the difference in wave impedance between the grout body and the surrounding rock is small, it is difficult to form an effective wave reflection interface, and the attenuation ability of dynamic disturbances such as blasting disturbance waves is limited. Although the wave-absorbing grouting technology developed in recent years attempts to enhance the wave reflection capability, it is still insufficient. While existing wave-absorbing grouting technologies offer attenuation effects, they suffer from drawbacks such as reduced grout strength due to the incorporation of low-impedance materials and increased tensile stress caused by interfacial reflection in single-layer structures, leading to detachment of the grout from the surrounding rock. These drawbacks are particularly problematic in deep, high-stress tunnels and other environments with stringent rock mass stability requirements. These defects can result in poor wave absorption and subsequent damage such as rockbursts. This invention addresses these issues by constructing a multi-layer composite support structure and leveraging the gradient distribution characteristics of wave impedance in each layer to achieve progressive reflection and dissipation of disturbance waves. This solves the problem of insufficient strength in existing wave-absorbing grouting technologies and avoids detachment caused by excessive tensile stress at the interface of single-layer structures through gradient design. In scenarios involving dynamic disturbances such as blasting excavation in tunnels using drill-and-blast methods, it can precisely control disturbance waves, significantly improving the stability of the surrounding rock and the safety of construction and operation.

[0016] In one specific embodiment of this disclosure, the wave impedance of the reinforcing layer 2 is greater than that of the first absorbing layer 3, and the wave impedance of the first absorbing layer 3 is greater than that of the second absorbing layer 4. This invention constructs a gradient system with wave impedance decreasing stepwise from the outside to the inside. The reinforcing layer 2 achieves initial attenuation of disturbance waves by forming a moderate wave impedance match with the surrounding rock. The first absorbing layer 3 further reduces wave energy through reflection and deformation dissipation by using a lower wave impedance. The second absorbing layer 4 achieves deep reflection and absorption of disturbance waves with extremely low wave impedance. In the drill-and-blast tunnel scenario, this gradient wave impedance system can accurately cope with disturbance waves generated by blasting and excavation. It achieves effective control of dynamic disturbances through stepwise reflection, dissipation and attenuation. While enhancing the integrity and stability of the surrounding rock, it significantly improves the tunnel's resistance to dynamic disturbances during construction and operation, and is suitable for the stringent requirements for rock mass stability in deep high-stress environments.

[0017] In one specific embodiment of this disclosure, the reinforcing layer 2 is based on cement and contains a mixture of silica fume and rubber powder to ensure that the 28-day compressive strength of the reinforcing layer is not less than 30 MPa. Silica fume can construct the skeleton of the grouting reinforcement material and improve its strength, while rubber powder can reduce the overall wave impedance of the material. The synergistic effect of the two can achieve wave impedance regulation while ensuring the high strength of the reinforcing layer, thus avoiding the drawback of the difficulty in attenuating dynamic disturbances by single cement grouting.

[0018] like Figure 3 As shown, in one specific embodiment of this disclosure, at least two grooves 5 are provided on the contact surface between the first absorbing layer 3 and the reinforcing layer 2. The grooves 5 are spaced apart along the height direction of the first absorbing layer 3. The first absorbing layer 3 is a rubber rod, and the grooves 5 on the rubber rod are 1-2 mm deep. The interval between the grooves 5 is 15 mm. At the same time, the roughness of the surface of the first absorbing layer 3 is improved by grinding, so that the grout can be fully filled into the groove and form an embedding effect. This significantly enhances the interface coupling ability between the rubber absorbing layer and the external grouting layer, ensuring a stable connection between the first absorbing layer 3 and the reinforcing layer 2, ensuring the integrity of the gradient wave impedance system, and allowing disturbance waves to be smoothly transmitted to the first absorbing layer 3 and reflected and dissipated by its low wave impedance characteristics. This provides support for the further attenuation of the subsequent second absorbing layer 4 and effectively copes with dynamic disturbances such as blasting disturbance waves.

[0019] In one specific embodiment of this disclosure, the wave impedance of the reinforcing layer 2 is 70%-90% of the wave impedance of the surrounding rock 1. The wave impedance range of the surrounding rock 1 enables the disturbance wave to produce a small reflection at the interface between the surrounding rock 1 and the reinforcing layer 2, thereby achieving the initial attenuation of the transmitted stress and avoiding the problem of interface tensile stress damaging the interface bonding stability caused by excessive wave impedance difference in the wave absorbing grouting technology.

[0020] like Figure 2As shown, in one specific embodiment of this disclosure, the second absorbing layer 4 is composed of at least two sections of aluminum foam. The adjacent sections of aluminum foam are connected by a snap-fit ​​structure. The segmented design greatly reduces the manufacturing difficulty of long aluminum foam rods, reduces the risk of bending and damage during transportation, and significantly reduces manufacturing and transportation costs. The snap-fit ​​structure can achieve a stable splicing of adjacent aluminum foam sections, ensuring that the overall error after splicing is controllable, and ensuring the structural integrity and wave impedance gradient continuity of the second absorbing layer 4. Example 2

[0021] This embodiment provides a method for evaluating microwave absorbing support structures within grouting holes. The method includes steps S1-S4, specifically comprising: Step S1: Obtain information on the development of fractures in the surrounding rock of the construction area; Step S2: Determine the location of the grouting holes based on the information on the development of fractures in the surrounding rock of the construction area; In this step, accurately understanding the fracture network in a deep, high-stress environment provides a decisive basis for the subsequent deployment of wave-absorbing structures, avoids reinforcement blind spots, and improves the effectiveness of disaster prevention from the source.

[0022] Step S3: Grouting holes are opened according to the location of the grouting holes, and reinforcement layer 2, first wave-absorbing layer 3 and second wave-absorbing layer 4 are sequentially set in the grouting holes from the outside to the inside to obtain a wave-absorbing support structure. In this step, the reinforcement layer 2 is prepared by on-site mixing, with cement, water, rubber, and silica fume added sequentially; the first absorbing layer 3 is processed in the factory according to the design dimensions, and its surface is roughened and grooves 5 are set, with a 3mm positioning step reserved at both ends of each section; the second absorbing layer 4 is prefabricated into segmented aluminum foam according to the porosity requirements. After the material preparation is completed, the slot dimensions are checked and the segmented aluminum foam is assembled. The assembled aluminum foam is then fitted into the hollow area of ​​the first absorbing layer 3, ensuring that the two fit tightly without gaps, and a sealant is applied at the sealing point. Apply epoxy resin and allow it to cure to prevent the aluminum foam from falling off. Place the combined aluminum foam and the first wave-absorbing layer 3 into the grouting hole, and then lay the grouting pipe. The grouting pipe is a 2cm diameter PVC grouting pipe. The grouting holes are drilled asymmetrically in a quincunx pattern on the pipe wall to avoid the outer wall of the rubber layer blocking the grouting holes. During the grouting process, rotate the position of the grouting pipe in time to ensure the grouting effect. It should be noted that grouting can be carried out at an appropriate pressure during the grouting process to ensure that the external reinforcement layer is fully bonded to the surrounding rock and to ensure the continuity of the wave impedance gradient.

[0023] Step S3 further includes steps S31-S33, which specifically include: Step S31: Perform acoustic wave testing on the surrounding rock 1 around the grouting hole to obtain the corresponding physical parameters of the surrounding rock; In this step, the physical parameters corresponding to the surrounding rock include the surrounding rock density and the longitudinal wave velocity of the surrounding rock.

[0024] Step S32: Calculate the surrounding rock wave impedance value based on the physical parameters corresponding to the surrounding rock; In this step, the surrounding rock impedance value can be obtained by multiplying the surrounding rock density by the surrounding rock longitudinal wave velocity.

[0025] Step S33: Determine the range of wave impedance settings for the reinforcement layer based on the wave impedance value of the surrounding rock.

[0026] In this step, the wave impedance of the reinforcement layer needs to be 70%-90% of the wave impedance value of the surrounding rock.

[0027] Step S4: Evaluate the wave absorption capacity of the wave-absorbing support structure and obtain the evaluation results.

[0028] Step S4 further includes steps S41-S46, which specifically include: Step S41: Obtain the physical parameters of each layer of material in the wave-absorbing support structure; Step S42: Determine the wave impedance corresponding to each layer of material based on the physical parameters of each layer of material; Step S43: Perform interface transmission and reflection analysis based on the wave impedance of each layer to obtain the transmission coefficient and reflection coefficient between each interface. Step S44: Apply disturbance loads to material specimens of different thicknesses using a split Hopkinson bar test system to obtain data on the propagation and attenuation of disturbance waves within the material. Step S45: Calculate the results based on the transmission coefficient and reflection coefficient between the interfaces and the propagation attenuation data of the disturbance wave inside the material. Step S45 further includes steps S451 and S452, which specifically include: Step S451: Obtain the interface bonding attenuation coefficient; Step S452: Calculate the results based on the interface bonding attenuation coefficient, the transmission coefficient and reflection coefficient between the interfaces, and the propagation attenuation data of the disturbance wave inside the material.

[0029] In this embodiment, by fabricating a composite material of rock mass, filling material, and rock mass, SHPB indoor tests are conducted, and the transmission and reflection coefficients are calculated and compared with the actual values ​​to obtain the interface bonding coupling coefficient. Then, the interface bonding coupling coefficient, the wave impedance of each layer of material, the theoretical transmission and reflection coefficients of each interface, and the nonlinear attenuation law of wave propagation inside the material are integrated into a calculation model to accurately predict the remaining energy of the disturbance wave after passing through the entire wave-absorbing support structure.

[0030] Step S46: Evaluate the wave absorption capacity of the wave-absorbing support structure based on the calculation results.

[0031] In this embodiment, as Figure 4 As shown, Figure 4 This diagram illustrates the propagation path of a disturbance wave through a wave-absorbing support structure used for grouting holes. The specific calculation process for the transmitted wave at the first joint interface (the contact surface between surrounding rock 1 and reinforced layer 2) is as follows: ; In the above formula, , These represent the transmitted stress and incident stress at the first joint interface, respectively. and These represent the wave impedance of the surrounding rock and the wave impedance of the reinforcement layer, respectively.

[0032] Attenuation tests were conducted on samples of different thicknesses (grout layer, rubber layer, and aluminum foam material) using the SHPB (Split Hopkinson Bar) testing system. Transmission and reflection coefficients were calculated using the wave impedance of the material and the incident bar. Based on this, the reflection attenuation and transmission enhancement effects of the disturbing wave at the interface were eliminated. Finally, the attenuation of the disturbing wave within the material as the propagation distance increased was obtained, specifically: ; In the above formula, It represents the propagation attenuation coefficient, used to indicate how the disturbed wave attenuates as it propagates within a material. This indicates the distance the disturbance wave travels within the material; This represents the material attenuation coefficient, used to represent the attenuation coefficient of different materials. A and B are both constant values. It should be noted that by using the SHPB system to conduct attenuation tests on samples of different thicknesses, a specific fitting formula can be obtained, and A and B are both constant values ​​in the fitting formula.

[0033] The specific calculation process for the disturbance wave propagating within reinforcement layer 2 is as follows: ; In the above formula, This represents the transmission stress after the propagation of reinforcement layer 2 has ended; and All values ​​are constants. The fitting formula obtained by conducting attenuation tests on reinforcement layers of different thicknesses using the SHPB system can be further used to determine... and Specific numerical values; This represents the material attenuation coefficient of the reinforcement layer; This indicates the propagation distance of the disturbance wave within the reinforced layer.

[0034] When the second joint interface (the contact surface between the reinforcing layer 2 and the first absorbing layer 3) is reached, the specific calculation process for the transmitted wave is as follows: ; In the above formula, This represents the transmitted stress at the second joint interface; This represents the wave impedance of the first absorbing layer.

[0035] After the disturbance wave propagates within the first absorbing layer 3, the specific calculation process for the incident wave is as follows: ; In the above formula, This represents the incident stress between the first absorbing layer 3 and the second absorbing layer 4. and All values ​​are constants. The fitting formula obtained by conducting attenuation tests on the first absorbing layer of different thicknesses using the SHPB system can be further used to determine... and ; Specific numerical value; This represents the material attenuation coefficient of the first absorbing layer 3; This indicates the propagation distance of the disturbance wave within the first absorbing layer.

[0036] When the third joint interface (the contact surface between the first absorbing layer 3 and the second absorbing layer 4) is reached, the specific calculation process for the transmitted wave is as follows: ;

[0037] In the above formula, This represents the wave impedance of the second absorbing layer.

[0038] After the disturbance wave propagates within the second absorbing layer 4, the specific calculation process for the incident wave is as follows: ;

[0039] In the above formula, This indicates the incident stress between the second absorbing layer 4 and the surrounding rock; and All values ​​are constants. The fitting formula obtained by conducting attenuation experiments on second absorbing layers of different thicknesses using the SHPB system can be further used to determine... and Specific numerical values; This represents the material attenuation coefficient of the second absorbing layer 4; This indicates the propagation distance of the disturbance wave within the second absorbing layer.

[0040] This invention not only achieves quantitative evaluation of the attenuation effect of disturbance waves, breaking the limitation of existing technologies in accurately measuring wave absorption performance, but also achieves optimal balance between energy absorption and reinforcement performance of gradient wave impedance structure through dynamic optimization, providing scientific and controllable technical support for the design and construction of wave absorption support structures for deep drilling and blasting methods in grouting holes.

[0041] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are 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, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0042] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0044] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for evaluating a wave-absorbing support structure inside a grouting hole, comprising using a wave-absorbing support structure inside a grouting hole, characterized in that, The microwave absorbing support structure used in the grouting hole includes: Surrounding rock (1), wherein the surrounding rock (1) is provided with grouting holes; A reinforcing layer (2) is disposed inside the grouting hole; The first absorbing layer (3) is disposed inside the reinforcing layer (2); The second wave-absorbing layer (4) is disposed inside the first wave-absorbing layer (3). The reinforcement layer (2), the first wave-absorbing layer (3) and the second wave-absorbing layer (4) are arranged sequentially from the outside to the inside in the grouting hole. The wave impedance of the reinforcement layer (2) is greater than that of the first wave-absorbing layer (3), and the wave impedance of the first wave-absorbing layer (3) is greater than that of the second wave-absorbing layer (4). The wave impedance of the reinforcement layer (2) is 70%-90% of the wave impedance of the surrounding rock. The evaluation method for the microwave absorbing support structure used in grouting holes includes the following steps: Obtain information on the development of fractures in the surrounding rock of the construction area; The location of the grouting holes is determined based on the information on the development of fractures in the surrounding rock of the construction area; Grouting holes are opened according to the location of the grouting holes, and a reinforcement layer (2), a first wave-absorbing layer (3) and a second wave-absorbing layer (4) are sequentially arranged from the outside to the inside in the grouting holes to obtain a wave-absorbing support structure. The wave absorption capability of the aforementioned wave-absorbing support structure is evaluated, including: Obtain the physical parameters of each layer of material in the microwave absorbing support structure; The wave impedance corresponding to each layer of material is determined based on the physical parameters of each layer of material. Based on the wave impedance of each layer, the interface transmission and reflection analysis is performed to obtain the transmission coefficient and reflection coefficient between each interface. By using a split Hopkinson bar test system to apply disturbance loads to material specimens of different thicknesses, data on the propagation and attenuation of disturbance waves within the material were obtained. Calculations are performed based on the transmission and reflection coefficients between the interfaces and the propagation attenuation data of the disturbance wave within the material, including: Obtain the interface bonding attenuation coefficient; The calculation results are obtained by calculating the interface bonding attenuation coefficient, the transmission coefficient and reflection coefficient between the interfaces, and the propagation attenuation data of the disturbance wave inside the material. The wave absorption capacity of the wave-absorbing support structure is evaluated based on the calculation results, and the evaluation results are obtained.

2. The evaluation method for wave-absorbing support structures within grouting holes according to claim 1, characterized in that, Grouting holes are made according to their designated locations, and a reinforcement layer, a first wave-absorbing layer, and a second wave-absorbing layer are sequentially arranged from the outside to the inside of the grouting holes, including: Acoustic wave testing was performed on the surrounding rock (1) around the grouting hole to obtain the corresponding physical parameters of the surrounding rock; The wave impedance value of the surrounding rock is obtained by calculation based on the physical parameters corresponding to the surrounding rock. The range of wave impedance settings for the reinforcement layer is determined based on the wave impedance value of the surrounding rock.

3. The evaluation method for wave-absorbing support structures within grouting holes according to claim 1, characterized in that: The reinforcing layer (2) is based on cement and contains a mixture of silica fume and rubber powder to ensure that the compressive strength of the reinforcing layer (2) is not less than 30 MPa after 28 days.

4. The evaluation method for wave-absorbing support structures within grouting holes according to claim 1, characterized in that: The contact surface between the first absorbing layer (3) and the reinforcing layer (2) is provided with at least two grooves (5), which are spaced apart along the height direction of the first absorbing layer (3).

5. The evaluation method for wave-absorbing support structures within grouting holes according to claim 1, characterized in that: The second absorbing layer (4) is composed of at least two sections of aluminum foam, and the adjacent sections of aluminum foam are connected by a snap-fit ​​structure.

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