Water-permeable damping anti-freezing light soil material and structural form

Abstract

The invention belongs to the technical field of tunnel engineering, and particularly relates to a water-permeable damping anti-freezing light soil material and a structural style. The prepared water-permeable shock-absorbing anti-freezing light soil material is composed of cement, fine sand, foam, carbon fibers, water-absorbent resin and a thickening agent, and a large number of pore structures are contained in the water-permeable shock-absorbing anti-freezing light soil material. The material realizes the conductive heating function through the carbon fibers, and can prevent water accumulation and freezing of a drainage channel and an entrance and exit area in a tunnel in a low-temperature environment; the porous structure of the material endows the material with light weight and excellent water permeability, and accumulated water in a tunnel structure can be rapidly discharged; in addition, due to the porous characteristic, vibration energy is effectively absorbed and dispersed under the traffic dynamic load effect, and the anti-seismic performance of the tunnel is improved. The innovative material has remarkable advantages in the aspects of water permeability, shock absorption and freezing prevention, and reliable guarantee is provided for long-term stability and safety of a tunnel structure.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel engineering, and in particular relates to a water-permeable shock-absorbing and anti-freezing lightweight soil material and a structural type. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] With the rapid advancement of tunnel engineering, tunnel construction has gradually extended to complex geological conditions and changeable hydrological environments. In these projects, seasonal fluctuations in groundwater levels and the long-term effects of traffic dynamic loads often have a significant impact on tunnel structures. Periodic changes in water levels may cause fatigue damage to the interfaces of tunnel segments, leading to leakage problems; at the same time, the vibrations generated by traffic dynamic loads may cause local soil liquefaction after being transmitted to the surrounding soil, increasing the risk of tunnel structure stability. In addition, the temperature at the entrances and exits of tunnels in northern regions is below zero in winter, which is prone to snow and ice accumulation, damaging structural components.

[0004] In order to solve the above problems, researchers have proposed technical solutions covering drainage design, shock-absorbing materials and antifreeze technology. However, these solutions mostly focus on solving the single technical problem of soil tunnels, which is difficult to meet the long-term safety requirements under the complex hydrogeological, climatic conditions and traffic dynamic load coupling. Therefore, it is necessary to develop a new type of tunnel filling material with drainage, shock absorption and antifreeze functions. Summary of the invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a permeable, shock-absorbing and anti-freezing lightweight soil material and structural type. The filling material prepared by the present invention has the functions of permeability, shock absorption and anti-freezing, and can be used in the tunnel filling ditch area. It can achieve efficient drainage and effectively alleviate traffic accidents caused by interface leakage and water accumulation; effectively absorb and disperse vibration energy, reduce tunnel structure fatigue damage and soil liquefaction and other diseases caused by vehicle vibration; built-in heating pipes can avoid problems such as failure of filling ditch drainage caused by freezing in winter.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions: The first aspect of the present invention provides a permeable shock-absorbing and antifreeze lightweight soil material, whose raw material composition includes, by weight: 20.20-47.19 parts of cement, 3.37-20.93 parts of fine sand, 1.6-3.73 parts of foam, 0.04-0.43 parts of carbon fiber, 0.27-1.59 parts of water-absorbing resin, 0.02-0.05 parts of thickener, and 8.76-22.28 parts of water.

[0007] Preferably, the cement is selected from one or more of ordinary Portland cement, white cement, aluminate cement, blast furnace slag cement, a mixture of Portland cement and mineral powder, and quick-setting cement.

[0008] Preferably, the fine sand is selected from one of natural fine sand, artificial fine sand and river sand, and has a particle size of 0.075-1 mm, more preferably 0.2-0.6 mm.

[0009] Preferably, the foam is made by physical foaming in a foaming machine through an air compressor, and the foam density is 42.5-65 kg / m 3 ; Further preferably, the foaming agent is selected from one or more of animal protein foaming agents, plant protein foaming agents and complex surfactants.

[0010] Preferably, the water-absorbing resin is selected from one or more of polyacrylic acid water-absorbing resins, polyvinyl alcohol water-absorbing resins, starch graft copolymer water-absorbing resins, cellulose-based water-absorbing resins, natural polymer water-absorbing resins and organic-inorganic composite water-absorbing resins.

[0011] Preferably, the thickener is selected from one or more of carboxymethyl cellulose (CMC), hydroxypropyl methyl cellulose (HPMC) and methyl cellulose (MC).

[0012] The second aspect of the present invention provides a method for preparing the above-mentioned permeable shock-absorbing and antifreeze lightweight soil material, which is specifically: first, a water-absorbing resin absorbs water to a gel state to obtain a water-absorbing resin gel, and then foams it. Then, water, cement, fine sand and carbon fiber are mixed and stirred until the slurry is uniform to obtain a cement slurry. The water-absorbing resin gel is added to the cement slurry to obtain a uniform slurry. Finally, the whipped foam and thickener are added to the slurry and stirred to obtain a mixture, which is the permeable shock-absorbing and antifreeze lightweight soil material.

[0013] Preferably, the preparation process of the cement slurry is carried out by stirring at 300-400 r / min for 60-120 s; further preferably, the preparation process of the cement slurry is carried out by stirring at 360 r / min for 90 s.

[0014] Preferably, the uniform slurry is prepared by stirring at 100-200 r / min for 30-90 s; further preferably, the cement slurry is prepared by stirring at 180 r / min for 60 s.

[0015] Preferably, the mixture is prepared by stirring at 100-200 r / min for 30-90 s; further preferably, the cement slurry is prepared by stirring at 180 r / min for 60 s.

[0016] The third aspect of the present invention provides an application of the above-mentioned permeable shock-absorbing and antifreeze lightweight soil material in the field of tunnels and underground engineering.

[0017] The fourth aspect of the present invention provides a high-efficiency drainage structure for a tunnel, comprising the permeable shock-absorbing and antifreezing lightweight soil material described in the first aspect, wherein the permeable shock-absorbing and antifreezing lightweight soil material is filled in a filling ditch of the high-efficiency drainage structure for a tunnel.

[0018] Preferably, the tunnel high-efficiency drainage structure also includes a longitudinal drainage pipe, a water collection ditch, a filling ditch and a filter screen; Among them, the longitudinal drainage pipe is arranged on the surrounding rock of the arch wall on both sides of the tunnel; the water collecting ditch is arranged between the tunnel invert arch and the track; the filling ditch is arranged between the water collecting ditch and the tunnel arch foot, and is symmetrically arranged on both sides of the water collecting ditch; the filter is arranged at the connection between the roads on both sides of the track, the filling ditch and the surrounding rock of the arch wall on both sides.

[0019] Preferably, the tunnel high-efficiency drainage structure is arranged in the tunnel within a range of ≥50 m from the entrance.

[0020] Further preferably, in the filling ditch within the tunnel entrance, heating rods are evenly laid every 0.5 to 1 m and poured into foam lightweight soil. Electric heating can effectively prevent water accumulation and freezing in the filling ditch, thereby ensuring the smooth flow and safety of the tunnel drainage channel and driving road.

[0021] Further preferably, the heating rods are arranged in a regular array in the plane of the filling groove, specifically in two rows with longitudinal spacing; the heating rods are evenly spaced in the row (transverse) and column (longitudinal) directions and meet the design requirement of a spacing of 0.5 to 1 meter.

[0022] Further preferably, when the air temperature is below 0°C, the power supply equipment can be turned on to quickly heat the filled permeable shock-absorbing and antifreeze lightweight soil material.

[0023] Preferably, the outer side of the tunnel surrounding rock where the longitudinal drainage pipe is located also includes a cast-in-place base and anti-backward push stones.

[0024] Preferably, the length of the filter is 0.8-1.2 m, preferably 1 m. After the surface water on the road is initially filtered through the filter, it seeps into the filling ditch and is discharged into the collection ditch.

[0025] Further preferably, the filter screen is made of a corrosion-resistant and wear-resistant high-strength material, and the filter screen aperture is set at 0.5-2 mm.

[0026] Further preferably, drainage holes are set on both sides of the ditch every 1.5~2 m along the track direction. The drainage holes have a diameter of 8~10 cm and are arranged at intervals up and down along the side walls of the ditch to enhance drainage efficiency and ensure that the accumulated water in the permeable shock-absorbing and antifreeze lightweight soil material can quickly flow into the ditch.

[0027] The beneficial effects achieved by one or more technical solutions of the present invention are as follows: (1) The permeable shock-absorbing and antifreeze lightweight soil material provided by the present invention can effectively absorb and disperse vibration energy under the action of traffic dynamic load, avoid fatigue damage to the tunnel structure caused by dynamic load impact, and reduce the risk of liquefaction of the surrounding soil.

[0028] (2) The permeable shock-absorbing and antifreeze lightweight soil material provided in this application has excellent water permeability, which can quickly drain the accumulated water in the tunnel, prevent the long-term damage to the tunnel caused by water pressure accumulation, and ensure traffic safety.

[0029] (3) The permeable shock-absorbing and antifreeze lightweight soil material provided by the present invention can effectively prevent water from accumulating and freezing in a low-temperature environment, thereby ensuring the smooth flow of the drainage system under low-temperature conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of a high-efficiency drainage structure for a tunnel designed for the present invention; Figure 2 It is a schematic diagram of the arrangement of drainage holes of the present invention.

[0031] Among them, 101-cast-in-place base; 102-anti-rockfall; 103-longitudinal drainage pipe; 104-drainage ditch; 105-filling ditch; 106-filter; 107-drainage hole; 108-side wall of drainage ditch; 109-heating rod. DETAILED DESCRIPTION

[0032] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0033] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless otherwise explicitly stated in the present invention, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof; Terminology explanation section: The terms "connected", "connected", and the like in the present invention should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements, or an interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0034] As mentioned above, the existing technical solutions mostly focus on solving the single technical problem of soil tunnels, which is difficult to meet the long-term safety requirements under the complex hydrogeological, climatic conditions and traffic dynamic load coupling. Therefore, the present invention proposes a new type of tunnel filling material with drainage, shock absorption and antifreeze functions, and designs the tunnel structure type accordingly.

[0035] The first typical embodiment of the present invention provides a permeable shock-absorbing and antifreeze lightweight soil material, whose raw material composition includes, by weight: 20.20~47.19 parts of cement, 3.37~20.93 parts of fine sand, 1.6~3.73 parts of foam, 0.04~0.43 parts of carbon fiber, 0.27~1.59 parts of water-absorbing resin, 0.02~0.05 parts of thickener, and 8.76~22.28 parts of water.

[0036] In one or more examples of this embodiment, the cement is selected from one or more of ordinary Portland cement, white cement, aluminate cement, blast furnace slag cement, a mixture of Portland cement and mineral powder, and quick-setting cement.

[0037] In one or more examples of this implementation mode, the fine sand is selected from one of natural fine sand, artificial fine sand and river sand, and has a particle size of 0.075-1 mm, and more preferably 0.2-0.6 mm.

[0038] In one or more embodiments of this embodiment, the foam is made by physical foaming of a foaming machine through an air compressor, and the foam density is 42.5-65 kg / m 3 ; Further preferably, the foaming agent is selected from one or more of animal protein foaming agents, plant protein foaming agents and complex surfactants.

[0039] In one or more examples of this embodiment, the water-absorbing resin is selected from one or more of polyacrylic acid water-absorbing resins, polyvinyl alcohol water-absorbing resins, starch graft copolymer water-absorbing resins, cellulose-based water-absorbing resins, natural polymer water-absorbing resins and organic-inorganic composite water-absorbing resins.

[0040] In one or more examples of this embodiment, the thickener is selected from one or more of carboxymethyl cellulose (CMC), hydroxypropyl methyl cellulose (HPMC) and methyl cellulose (MC).

[0041] The second typical embodiment of the present invention provides a method for preparing the above-mentioned permeable shock-absorbing and antifreeze lightweight soil material, which is specifically: first, the water-absorbing resin absorbs water to a gel state to obtain a water-absorbing resin gel, and the foam is whipped, and then water, cement, fine sand and carbon fiber are mixed and stirred until the slurry is uniform to obtain a cement slurry, the water-absorbing resin gel is added to the cement slurry to obtain a uniform slurry, and finally the whipped foam and thickener are added to the slurry and stirred to obtain a mixture, which is the permeable shock-absorbing and antifreeze lightweight soil material.

[0042] In one or more examples of this embodiment, the preparation process of the cement slurry is carried out by stirring at 300-400 r / min for 60-120 s.

[0043] In one or more examples of this embodiment, the uniform slurry is prepared by stirring at 100-200 r / min for 30-90 s.

[0044] In one or more examples of this implementation mode, the preparation process of the mixture is carried out by stirring at 100-200 r / min for 30-90 s.

[0045] A third typical implementation of the present invention provides an application of the above-mentioned permeable shock-absorbing and antifreeze lightweight soil material in the field of tunnels and underground engineering.

[0046] A fourth typical embodiment of the present invention provides a high-efficiency drainage structure for a tunnel, comprising the above-mentioned permeable shock-absorbing and antifreezing lightweight soil material, wherein the permeable shock-absorbing and antifreezing lightweight soil material is filled in a filling ditch of the high-efficiency drainage structure for a tunnel.

[0047] In one or more embodiments of this implementation mode, the high-efficiency drainage structure for tunnels further includes a longitudinal drainage pipe, a water collection ditch, a filling ditch and a filter screen; Among them, the longitudinal drainage pipe is arranged on the surrounding rock of the arch wall on both sides of the tunnel; the water collecting ditch is arranged between the tunnel invert arch and the track; the filling ditch is arranged between the water collecting ditch and the tunnel arch foot, and is symmetrically arranged on both sides of the water collecting ditch; the filter is arranged at the connection between the roads on both sides of the track, the filling ditch and the surrounding rock of the arch wall on both sides.

[0048] In one or more embodiments of this implementation mode, the tunnel high-efficiency drainage structure is arranged in the tunnel within a range of ≥50 m from the entrance.

[0049] In one or more embodiments of this implementation mode, heating rods are evenly laid every 0.5 to 1 m in the filling ditch within the tunnel entrance and poured in foam lightweight soil. Electric heating can effectively prevent water accumulation and freezing in the filling ditch, thereby ensuring the smooth flow and safety of the tunnel drainage channel and driving road.

[0050] In one or more embodiments of this implementation mode, the heating rods are arranged in a regular array in the plane of the filling groove, specifically in two rows with longitudinal spacing; the heating rods are evenly spaced in the row (transverse) and column (longitudinal) directions and meet the design requirement of a spacing of 0.5 to 1 meter.

[0051] In one or more embodiments of this implementation mode, when the air temperature is below 0°C, the power supply device can be turned on to quickly heat the filled permeable shock-absorbing and antifreeze lightweight soil material.

[0052] In one or more embodiments of this implementation mode, the outer side of the tunnel surrounding rock where the longitudinal drainage pipe is located also includes a cast-in-place base and anti-backward push stones.

[0053] In one or more embodiments of this implementation mode, the length of the filter screen is 0.8~1.2 m, preferably 1 m. After the surface water on the road is initially filtered through the filter screen, it seeps into the filling ditch and is discharged into the collection ditch.

[0054] In one or more embodiments of this implementation mode, the filter screen is made of a high-strength material that is resistant to corrosion and wear, and the pore size of the filter screen is set at 0.5-2 mm.

[0055] In one or more embodiments of this implementation mode, drainage holes are set on both sides of the ditch along the track direction every 1.5~2 m. The diameter of the drainage holes is 8~10 cm. They are arranged at intervals up and down along the side walls of the ditch to enhance drainage efficiency and ensure that the accumulated water in the permeable shock-absorbing and antifreeze lightweight soil material can quickly flow into the ditch.

[0056] In one or more embodiments of this implementation mode, the water-based shock-absorbing and antifreeze lightweight soil material is paved by cast-in-place method. First, cement, fine sand, water, foam, carbon fiber, water-absorbing resin and thickener are fully mixed in proportion to form a uniform slurry. The slurry is then poured directly into the tunnel filling ditch or the entrance and exit paving area to tightly combine the material with the structural foundation. After pouring, wet curing is carried out, and the general curing period is 7-10 days.

[0057] Raw materials and functions: Water-absorbent resin: Water-absorbent resin will absorb water and swell during the material preparation stage, and release water during the hydration and molding stage to promote hydration reaction and reduce volume. This process results in a large cavity inside the material, thereby forming a rich pore structure, which helps to enhance the water permeability and shock absorption of the material; at the same time, the water-absorbent resin has water-absorbent swelling characteristics and low-temperature stability, can absorb and retain water, and slow down the freezing rate of water; in addition, the water-absorbent resin becomes a gel state after absorbing water and swelling, and its elasticity is enhanced. When subjected to traffic dynamic loads, the water-absorbent resin can effectively disperse and block the propagation of vibration energy.

[0058] Foam: Foam provides a large amount of pore structure for the material, which can effectively reduce the density of the material and increase its water permeability, allowing moisture to be quickly removed.

[0059] Carbon fiber: When carbon fiber is combined with other components as a reinforcing material, the connectivity of the pores inside the material will be increased by overlapping each other, forming a water-permeable connection channel and improving the water-permeable effect; at the same time, carbon fiber has high tensile strength and elastic modulus, which can significantly improve the overall mechanical properties of the material, and form a microscopic elastic response area inside the material, which can absorb and convert part of the vibration energy into internal heat, thereby reducing the transmission efficiency of vibration to the tunnel structure; in addition, carbon fiber has good electrical and thermal conductivity, which can quickly transfer the heat of the heating pipe to the surrounding materials, and then use the conducted heat to prevent moisture from freezing at the entrance and exit of the tunnel.

[0060] As described above, the permeable shock-absorbing and antifreeze lightweight soil material prepared by the present invention realizes the three major functions of water permeability, shock absorption and antifreeze through the interaction of various components. The synergistic effect of various components in the material not only improves the overall performance of the material, but also enables it to have excellent adaptability and versatility under different environmental conditions, thereby providing long-term and stable guarantees for engineering applications such as tunnels. The proportions of the various components of the material can be adjusted according to the actual needs of the tunnel project to meet the water permeability and shock absorption requirements under different environmental conditions.

[0061] The present invention will be further described in detail below in conjunction with specific embodiments. It should be noted that the specific embodiments are intended to explain the present invention rather than to limit it.

[0062] Embodiments 1 to 4: This embodiment provides four types of water-permeable shock-absorbing and antifreeze lightweight soil materials. The proportions of the raw materials are shown in Table 1. The preparation method thereof includes the following steps: 1) The water-absorbing resin is pre-absorbed to a gel state, and foam is produced by a foaming machine; 2) Pour water, cement, fine sand and carbon fiber into a mixing bucket in sequence, and stir with a handheld stirrer at 360 r / min for 90 s until the slurry is uniform; 3) pouring the prepared water-absorbing resin gel according to the weight proportions described in the first aspect into the stirred cement slurry, and stirring at a speed of 180 r / min for 60 s using a hand-held stirrer to form a uniform slurry; 4) Add the whipped foam and thickener according to the weight proportions described in the first aspect, and stir thoroughly at 180 r / min for 60 s using a hand-held stirrer to obtain the product.

[0063] The raw material proportions (parts by weight) of the lightweight soil materials prepared in specific embodiments 1 to 4 are shown in Table 1: Table 1

[0064] Comparative Examples 1 to 21: This comparative example provides a series of permeable shock-absorbing and antifreeze lightweight soil materials. The proportions of each raw material are shown in Table 2. The difference from Example 1 lies in the differences in components and portions, and the specific preparation methods are the same.

[0065] The raw material proportions (parts by weight) of the lightweight soil materials prepared in specific comparative examples 1 to 21 are shown in Table 2: Table 2

[0066] Embodiment 5: This embodiment provides a highly efficient drainage structure like Figure 1 As shown, the efficient drainage structure includes a longitudinal drainage pipe 103, a water collecting ditch 104, a filling ditch 105 and a filter screen 106. The longitudinal drainage pipe 103 is arranged on the surrounding rock of the arch wall on both sides of the tunnel; the water collecting ditch 104 is arranged between the tunnel invert arch and the track; the filling ditch 105 is arranged between the water collecting ditch 104 and the tunnel arch foot, and is filled with the permeable shock-absorbing and antifreeze lightweight soil material prepared in Examples 1 to 4 of the present invention, and is symmetrically arranged on both sides of the water collecting ditch 104; the filter screen 106 is arranged at the connection between the roads on both sides of the track, the filling ditch and the surrounding rock of the arch wall on both sides.

[0067] When water accumulates or seeps inside the tunnel, the seepage water around the tunnel is directly discharged into the collecting ditch 104 through the longitudinal drainage pipe 103; the water accumulated on both sides of the road can seep into the filling ditch 105 through the filter screen 106. Due to the excellent permeability of the permeable shock-absorbing and anti-freezing lightweight soil, the water can quickly enter the collecting ditch 104 through the filling ditch 105 and be discharged from the tunnel area in a centralized manner.

[0068] In the above scheme, drainage holes 107 (such as 10 cm in diameter) are provided on the side walls 108 of the ditch 104 at intervals of 2 meters along the road direction. Figure 2These drainage holes are arranged at intervals up and down the side wall of the ditch to ensure that the accumulated water can quickly flow into the ditch 104.

[0069] The filter screen 106 in this experimental example is arranged above the filling ditch 105 on both sides of the road at the tunnel pipe interface, and is used to efficiently collect and guide road surface water. It can effectively filter out mud and impurities in the water to prevent it from entering the permeable lightweight soil filling ditch, thereby ensuring the smoothness of the drainage system.

[0070] The filling groove 105 in this experimental example has good shock absorption performance. When subjected to traffic dynamic load or other vibrations, it will undergo slight deformation and compression, effectively absorbing and dispersing vibration energy, and preventing vibration waves from being directly transmitted to the tunnel structure and surrounding soil. In addition, the relatively "soft" characteristics of the material effectively buffer the vibration impact, reducing the risk of liquefaction of the tunnel structure and surrounding soil.

[0071] The filling groove 105 in this experimental example can also realize the heating function by being powered on, effectively preventing the accumulation of water from freezing and ensuring the smoothness of the drainage system. In addition, a heating rod 109 is arranged in the filling groove 105 at the entrance and exit of the tunnel. Through the synergistic effect of the heating rod and the material, the road surface and drainage channel in the low temperature environment are further prevented from freezing, providing a more reliable winter drainage and traffic safety guarantee for the tunnel structure.

[0072] In the above scheme, heating rods 109 are evenly laid every 0.5 to 1 meter in the filling trench 105 within 50 meters of the tunnel entrance and exit. The heating rods are heated by electricity to increase the internal temperature of the material under low temperature or icy conditions, effectively preventing water accumulation and ice formation. When encountering snow or icy weather, the heating rods work together with the self-heating, permeable, shock-absorbing and anti-freezing lightweight soil material to quickly melt the snow and ice, ensure driving safety, and reduce the risk of passing due to icing in winter.

[0073] Test Example 1: Based on the high-efficiency drainage structure type for tunnels set in Example 5, this test example is to test the relevant performance of the permeable shock-absorbing and antifreeze lightweight soil materials prepared in Examples 1 to 4 and Comparative Examples 1 to 21, as shown in Table 3: Table 3

[0074] From the data analysis in Table 3, we can get: Compared with Example 1, although Examples 2 to 4 meet the basic industry requirements of water permeability, antifreeze performance and shock absorption performance (the lower the dynamic modulus value, the better the shock absorption performance) (according to the relevant requirements in the "Highway Roadbed Design Specifications", when foam lightweight soil is used for roadbed filling, the compressive strength must be not less than 0.8MPa), there are still deficiencies in performance balance. Example 2 has lower water permeability, and its antifreeze and shock absorption performance are not as good as Example 1, but its compressive strength is enhanced; although Example 3 has higher water permeability, its shock absorption performance and compressive strength are significantly reduced, and it is difficult to meet the engineering bearing requirements; Example 4's antifreeze performance only meets the basic requirements, and its water permeability, shock absorption and strength are all reduced. Therefore, the components and contents added in Example 1 are optimally regulated, that is, high water permeability, high antifreeze performance, high shock absorption performance and high compressive strength are obtained at the same time; in contrast, the changes in Examples 2 to 4 often lead to a decrease in other performances when improving certain performances, indicating that the ratio between the components needs to be precisely regulated to meet the requirements of complex working conditions for the comprehensive performance of materials. (2) Compared with Example 1, Comparative Examples 1 to 6 investigated the component carbon fibers: a) Comparative Example 1 does not add carbon fiber. Compared with Example 1, the water permeability, antifreeze performance and strength of the material are significantly reduced, and the shock absorption performance is slightly improved. In the solidification process of the permeable shock-absorbing antifreeze lightweight soil material, the supporting role of carbon fiber can prevent some micropores from being blocked due to collapse or material shrinkage, ensuring a higher effective porosity inside the material. At the same time, carbon fiber has a certain water conductivity, which can guide the migration of water along the path of fiber distribution, thereby forming a more efficient drainage network. The lack of carbon fiber makes the material lack this enhanced network structure, resulting in a significant reduction in water permeability. In addition, carbon fiber has strong electrical and thermal conductivity. When no carbon fiber is added, the material cannot effectively and evenly transfer heat from the heating pipe, resulting in a decrease in antifreeze performance. However, due to the reduction in the overall rigidity of the material, it can absorb more vibration energy under dynamic load, so the shock absorption performance is slightly improved. After adding a small amount of carbon fiber in Comparative Example 2, the antifreeze performance and compressive strength of the material are improved. This is because a small amount of carbon fiber plays a "bridging" role in the matrix, enhances the microstructural stability inside the material, and improves the distribution and connectivity of the pores. After adding excessive carbon fiber in comparative example 3, although the antifreeze performance is greatly improved, the excessive fiber is easy to produce "agglomeration" phenomenon inside the material, blocking the water permeable channel. At the same time, the fiber aggregation effect causes stress concentration inside the material, resulting in a decrease in its compressive strength.

[0075] b) While keeping the total number of components unchanged, comparative example 4 did not add carbon fiber, and the water permeability, shock absorption performance and strength of the material in comparative example 1 were slightly improved, but the strength was reduced. This is because the increase of foam and water-absorbing resin increases the porosity, thereby improving the water permeability and the buffering capacity of the material. At the same time, the water-absorbing resin easily absorbs water to form a flexible gel, reducing the amount of free water in the pores and improving the antifreeze performance of the material. However, the lack of carbon fiber causes the material to lose the supporting effect of the reinforcing network, resulting in a weakening of the compressive strength. A small amount of carbon fiber was added to comparative example 5, and the antifreeze performance and compressive strength of the material were improved, but the water permeability and shock absorption performance were slightly reduced. The addition of a small amount of carbon fiber restored the role of part of the reinforcing structure, which improved the rigidity and stability of the material; however, due to the high content of foam and water-absorbing resin, a small amount of carbon fiber could not overlap each other inside the material and form a sufficiently effective water-conducting structure, resulting in a slight decrease in water permeability. In comparative example 6, excessive carbon fiber was added, and the foam and water-absorbing resin were significantly reduced. The antifreeze performance and compressive strength of the material were improved, but the water permeability and shock absorption performance were reduced. The high thermal conductivity of carbon fiber helps to quickly and evenly disperse the temperature in low-temperature environments, reducing the risk of local frost damage. However, due to the reduction in the content of foam and water-absorbing resin, the porosity of the material has dropped significantly, and the water permeability and shock absorption performance have decreased.

[0076] (3) Compared with Example 1, Comparative Examples 7 to 12 investigated the component foams: 1) Comparative Example 7 did not add foam, and showed high compressive strength, but poor water permeability, antifreeze and shock absorption performance. This is because the lack of foam leads to a lower porosity inside the material, reducing the water discharge channel, while the rigidity of the material is enhanced, and there is a lack of flexible buffer structure to absorb and disperse vibration energy, so the shock absorption performance is weak. After adding a small amount of foam to Comparative Example 8, the porosity of the material increased, the flexibility was enhanced, and the water permeability, antifreeze and shock absorption performance were significantly improved. After adding excessive foam to Comparative Example 9, the material porosity was too high, the structure was loose, and the compressive strength decreased significantly, which did not meet the basic bearing capacity requirements.

[0077] 2) While keeping the total number of components unchanged, comparative example 10 did not add foam, and the water permeability, antifreeze and shock absorption performance of the material were improved compared with comparative example 7, but the compressive strength was significantly reduced. This is because when the foam was not added, its proportion was distributed to the carbon fiber and the water-absorbing resin. The increase of the water-absorbing resin optimized the pore structure through water absorption and expansion, enhanced the flexibility of the material, and further improved the antifreeze and shock absorption performance of the material. The increase of carbon fiber further enhanced the thermal conductivity and promoted the improvement of antifreeze performance. However, due to the lack of foam, the internal porosity of the material was insufficient, and the excessive water-absorbing resin caused the rigidity to decrease, which eventually led to a significant decrease in compressive strength. After adding a small amount of foam to comparative example 11, the water permeability and shock absorption performance of the material were improved, the increase in the pore structure made the water discharge smoother, and the flexibility was enhanced, which could better absorb and disperse the vibration energy; however, due to the small amount of foam and the high ratio of fiber and water-absorbing resin, the uniformity of the internal pore structure of the material was limited, the fiber reinforcement effect could not be fully exerted, and the flexible buffering capacity of the water-absorbing resin was also limited, so the shock absorption effect was not improved much. In comparative example 12, excessive foam was added to increase the porosity inside the material, making the material more flexible under dynamic load, thereby improving the shock absorption performance. However, due to too little fiber and water-absorbing resin, a sufficient reinforcement network could not be formed, and its thermal conductivity and antifreeze performance were not apparent. In addition, although foam alone improved the shock absorption performance, due to the lack of fiber reinforcement support and the regulating effect of water-absorbing resin, the mechanical properties of the material were improved to a small extent.

[0078] (4) Compared with Example 1, Comparative Examples 13 to 18 investigated the component water-absorbing resins: a) Comparative Example 13 has weakened water permeability and antifreeze performance due to the lack of water-absorbing resin. Water-absorbing resin can fill the uneven micropores inside the material and improve the pore distribution and connectivity through water absorption and expansion, thereby forming a more effective water permeable channel. When no water-absorbing resin is added, the pore structure in the material lacks regulation, the penetration and discharge of water are hindered, and the water permeability is significantly weakened. At the same time, in a low temperature environment, the lack of water-absorbing resin makes the material lose the ability to relieve ice expansion pressure and prevent water from freezing, and the antifreeze performance is significantly reduced. After adding a small amount of water-absorbing resin in Comparative Example 14, the water permeability, antifreeze performance and shock absorption performance are significantly improved. The water-absorbing resin enhances the stability of the material in a low temperature environment by forming a flexible gel structure, and at the same time improves the ability to absorb and buffer vibration energy. In Comparative Example 15, an excessive amount of water-absorbing resin is added. Although the water permeability and shock absorption performance are further improved, the antifreeze performance and compressive strength are significantly reduced. Excessive water-absorbing resin will cause the material to be too loose after water absorption and expansion, weakening the overall rigidity and bearing capacity of the material. In addition, too much water-absorbing resin can easily cause the material to absorb excessive water and expand unevenly, exacerbating the risk of freeze-thaw damage at low temperatures, ultimately leading to a decrease in antifreeze performance.

[0079] b) While keeping the total number of components unchanged, no water-absorbing resin was added to Comparative Example 16, and the water permeability, antifreeze performance and shock absorption performance of the material were improved compared with Comparative Example 13. This is because the increase in foam improves the porosity and flexibility, and the thermal conductivity and reinforcement of carbon fiber effectively compensate for the lack of antifreeze performance caused by the lack of water-absorbing resin, but due to the lack of gelation of water-absorbing resin, the improvement of antifreeze performance is limited. After adding a small amount of water-absorbing resin to Comparative Example 17, all the properties of the material are improved. However, due to the relatively large amount of foam and fiber added, although the mechanical properties of the material are enhanced, too much fiber will cause the heat conduction channel to be too concentrated, so that the improvement of the antifreeze performance of the material is limited. In Comparative Example 18, an excessive amount of water-absorbing resin is added. Although the water permeability and shock absorption performance are further improved, the material is too soft, the structure becomes loose and fragile, and the compressive strength is significantly reduced, which cannot meet the engineering bearing requirements. At the same time, due to the small amount of fiber, an effective reinforcement network cannot be formed, resulting in the lack of sufficient thermal conductivity of the material to evenly disperse the heat in a low temperature environment, which limits the further improvement of the antifreeze performance.

[0080] (5) Compared with Example 1, Comparative Example 19 does not add carbon fiber and water-absorbing resin, and the other components and contents are consistent with Example 1; from the data comparison, it can be seen that the water permeability, antifreeze performance and shock absorption performance of the material are significantly reduced. This is mainly because the carbon fiber not only plays a reinforcing role in the material, but also improves the shock absorption and antifreeze performance by improving the pore distribution and forming a thermal conductive network; the water-absorbing resin increases the internal porosity of the material by absorbing water and expanding, and at the same time inhibits the freezing of water in a low temperature environment, thereby enhancing the antifreeze performance. In addition, when the water-absorbing resin and foam work together, they can further optimize the pore structure, so that the water permeability and shock absorption are balanced, while the carbon fiber can limit the deformation of the material and avoid the decrease in mechanical properties due to excessive foam. Therefore, the synergistic effect of carbon fiber, water-absorbing resin and foam is crucial in improving the water permeability, antifreeze performance and shock absorption performance of the material. The lack of any of these components will destroy this balance and lead to a decrease in material performance.

[0081] (6) Compared with Example 1, Comparative Example 20 does not add water-absorbing resin and foam, and the other components and contents are consistent with those of Example 1; from the data comparison, it can be seen that the absence of water-absorbing resin and foam leads to the reduction of various properties. Due to the lack of water-absorbing resin, the material loses the ability to absorb water and expand to form gel in a low-temperature environment, and cannot effectively prevent water from freezing, and the antifreeze performance is significantly weakened; at the same time, the lack of water-absorbing resin also reduces the optimization effect of the pore structure, affecting the water permeability and shock absorption. The lack of foam further leads to a decrease in porosity, difficulty in water discharge, increased overall rigidity of the material, and decreased shock absorption. In addition, due to the synergistic effect of water-absorbing resin and foam, the structural continuity and bearing capacity of the material can be maintained while enhancing the water permeability and shock absorption. However, due to the lack of these two components, Comparative Example 20 shows problems such as insufficient water permeability, weak antifreeze performance, poor shock absorption effect, and limited strength improvement. This shows that the combination of water-absorbing resin and foam can improve the performance of the material while ensuring its applicability in actual engineering.

[0082] (7) Compared with Example 1, Comparative Example 21 does not add foam and carbon fiber, and the other components and contents are consistent with Example 1; from the data comparison, it can be seen that: without adding foam, the internal porosity of the material is significantly reduced, the water permeability is insufficient, and the flexible buffering effect provided by the foam is lost, and the shock absorption performance is deteriorated; without adding carbon fiber, the material loses the ability to enhance and disperse vibration energy, and the thermal conductivity is weakened, affecting the antifreeze performance. In addition, the synergistic effect of foam and carbon fiber can optimize the pore structure and improve the comprehensive performance of the material in Example 1, while Comparative Example 21, due to the lack of these two key components, shows the problems of excessive rigidity and insufficient pore structure, resulting in a comprehensive decline in water permeability, antifreeze and shock absorption performance.

[0083] As described above, in Example 1, the synergistic effect between foam, water-absorbing resin and carbon fiber significantly improves the various properties of the permeable shock-absorbing and antifreeze lightweight soil. First, the addition of foam increases the porosity of the material, effectively improving its water permeability. At the same time, the water-absorbing resin improves the pore structure of the material through expansion, enhances its water permeability and improves shock-absorbing performance. The combination of the two ensures that the lightweight soil material has a good shock-absorbing effect while having high water permeability.

[0084] Secondly, the synergy of foam and carbon fiber improves shock absorption performance. Foam provides a larger deformation space, allowing the material to better absorb energy when subjected to vibration, while the addition of carbon fiber enhances the material's impact resistance and crack resistance, making it more resistant to earthquakes under dynamic loads. The combination of the two ensures the optimization of lightweight soil materials in terms of shock absorption performance.

[0085] Finally, the synergistic effect of water-absorbing resin and carbon fiber enhances the antifreeze performance. The water-absorbing resin expands by absorbing water, reducing the damage to the material structure when the water freezes, while the carbon fiber helps the material heat more evenly in a low-temperature environment by improving thermal conductivity and preventing water from freezing in the pores. The combination of the two makes the lightweight soil material have better antifreeze properties at low temperatures.

[0086] In summary, the synergistic effect between foam, water-absorbent resin and carbon fiber plays a positive role in lightweight soil materials, which not only optimizes their water permeability and shock absorption, but also enhances their antifreeze performance, making the material have stronger comprehensive performance and adapting to diverse engineering needs.

[0087] Therefore, through the design of the permeable shock-absorbing and antifreezing lightweight soil filling material and the optimized drainage system in this embodiment, the drainage capacity, seismic performance and antifreezing capacity of the tunnel structure are significantly improved. This structural type forms an efficient drainage channel at the bottom of the tunnel, which can drain the accumulated water in time and prevent water pressure accumulation. At the same time, the material can absorb and disperse the vibration energy generated by the dynamic load, thereby improving the seismic resistance and safety of the tunnel structure.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A water-permeable shock-absorbing and antifreeze lightweight soil material, characterized in that: The raw material composition includes, by weight: 20.20-47.19 parts of cement, 3.37-20.93 parts of fine sand, 1.6-3.73 parts of foam, 0.04-0.43 parts of carbon fiber, 0.27-1.59 parts of water-absorbing resin, 0.02-0.05 parts of thickener, and 8.76-22.28 parts of water.

2. The water-permeable shock-absorbing and antifreeze lightweight soil material according to claim 1, characterized in that: The cement is selected from one or more of ordinary Portland cement, white cement, aluminate cement, blast furnace slag cement, a mixture of Portland cement and mineral powder, and quick-setting cement; The fine sand is selected from one of natural fine sand, artificial fine sand and river sand, and has a particle size of 0.075-1 mm; The foam is produced by physical foaming in a foaming machine through an air compressor, and the foam density is 42.5-65 kg / m 3 ; The foaming agent is selected from one or more of an animal protein foaming agent, a plant protein foaming agent and a composite surfactant; The water-absorbing resin is selected from one or more of polyacrylic acid water-absorbing resin, polyvinyl alcohol water-absorbing resin, starch graft copolymer water-absorbing resin, cellulose-based water-absorbing resin, natural polymer water-absorbing resin and organic-inorganic composite water-absorbing resin; The thickener is selected from one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose and methyl cellulose.

3. A method for preparing the permeable shock-absorbing and antifreeze lightweight soil material according to any one of claims 1 to 2, characterized in that: Specifically, the water-absorbing resin is firstly made to absorb water to a gel state to obtain a water-absorbing resin gel, and foam is whipped, and then water, cement, fine sand and carbon fiber are mixed and stirred until the slurry is uniform to obtain cement slurry, and the water-absorbing resin gel is added to the cement slurry to obtain a uniform slurry, and finally the whipped foam and thickener are added to the slurry and stirred to obtain a mixture, which is a water-permeable shock-absorbing and antifreeze lightweight soil material; The cement slurry is prepared by stirring at 300-400 r / min for 60-120 s; The uniform slurry is prepared by stirring at 100-200 r / min for 30-90 s; The preparation process of the mixture is carried out by stirring at 100-200 r / min for 30-90 s.

4. An application of the permeable shock-absorbing and antifreeze lightweight soil material as described in any one of claims 1 to 2 in the field of tunnels and underground engineering.

5. A high-efficiency drainage structure for a tunnel, characterized in that: It comprises the water-permeable shock-absorbing and antifreezing lightweight soil material as described in any one of claims 1 to 2, wherein the water-permeable shock-absorbing and antifreezing lightweight soil material is filled in a filling ditch of the tunnel with a high-efficiency drainage structure.

6. The high-efficiency drainage structure for tunnels according to claim 5, characterized in that: The high-efficiency drainage structure for the tunnel also includes a longitudinal drainage pipe, a water collection ditch and a filter screen; Among them, the longitudinal drainage pipe is arranged on the surrounding rock of the arch wall on both sides of the tunnel; the water collecting ditch is arranged between the tunnel invert arch and the track; the filling ditch is arranged between the water collecting ditch and the tunnel arch foot, and is symmetrically arranged on both sides of the water collecting ditch; the filter is arranged at the connection between the roads on both sides of the track, the filling ditch and the surrounding rock of the arch wall on both sides.

7. The high-efficiency drainage structure for tunnels according to claim 5, characterized in that: The tunnel high-efficiency drainage structure is arranged in the tunnel within a range of ≥50 m from the entrance.

8. The high-efficiency drainage structure for tunnels according to claim 7, characterized in that: In the filling trench within the tunnel entrance, heating rods are evenly laid every 0.5~1 m and poured in the foam lightweight soil; the heating rods are arranged in a regular array in the plane of the filling trench, specifically in two rows with longitudinal spacing; the heating rods are evenly spaced in the row and column directions and meet the design requirement of 0.5~1 meter spacing; when the temperature is below 0℃, turn on the power-on equipment to heat the permeable shock-absorbing and antifreeze lightweight soil material.

9. The high-efficiency drainage structure for tunnels according to claim 6, characterized in that: The outside of the tunnel surrounding rock where the longitudinal drainage pipe is located also includes a cast-in-place base and anti-backward push stones; The length of the filter is 0.8~1.2 m. After the surface water on the road is initially filtered through the filter, it seeps into the filling ditch and is discharged into the collection ditch. The filter is made of high-strength material that is corrosion-resistant and wear-resistant, and the filter aperture is set at 0.5~2 mm.

10. The high-efficiency drainage structure for tunnels according to claim 6, characterized in that: Drainage holes are set at intervals of 1.5 to 2 m on both sides of the ditch along the track direction. The diameter of the drainage holes is 8 to 10 cm and they are arranged at intervals up and down along the side wall of the ditch to enhance drainage efficiency.

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