Foundation structure for treating reed root system in airport pavement area

Abstract

The utility model discloses a foundation structure for treating reed root systems in an airport pavement area, relates to the field of foundation structures, and aims to solve the problems that the reed root systems in the existing airport pavement area are deep and tenacious in vitality, and the risk that the reed root systems penetrate through the pavement structure is difficult to thoroughly block by a single measure. A composite geomembrane adopted by the isolating layer upwards prevents water from entering the isolating layer in advance, prevents quicklime from losing efficacy, downwards isolates air, sunlight and herbicide from leaking, cuts off root growth conditions and prevents underground water from being polluted, the isolating layer adopts quicklime and herbicide, and the quicklime heats when encountering water and burns roots to achieve physical killing. The herbicide is absorbed by the root system to realize chemical killing, the two synergistically improve the inhibition efficiency, and the separation layer and the isolation layer form a chemical killing and physical blocking double-layer barrier, so that the root system is effectively prevented from penetrating through the road surface.

Description

Technical Field

[0001] This utility model relates to the field of foundation structures, and in particular to a foundation structure for treating reed root systems in airport pavement areas. Background Technology

[0002] In the construction of civil aviation airports, there are various complex geological problems. Some of these problems are difficult to handle and have hindered the rapid construction and development of civil aviation airports. Among them, reeds have deep roots and strong vitality. If the reed roots in the airport pavement construction area are not properly treated, they may grow upwards and break through the pavement. During the process of the roots invading the foundation, they will also squeeze the surrounding foundation soil, causing changes in the structure of the foundation soil, endangering the safety of the pavement structure, and thus affecting the safe operation of the airport.

[0003] Reeds are not picky about terrain and can grow in any place with water or dampness, with roots that can penetrate two to three meters deep into the ground. Currently, conventional methods for treating reed roots include deep excavation and backfilling, which involves excessive excavation and replacement work and is too expensive; herbicide application requires site-specific testing, considering the natural environment and climate, and involves long testing periods that cannot meet construction schedule requirements, and large-scale herbicide application can easily cause environmental pollution and seep into groundwater, endangering water safety; quicklime is used to inhibit growth, but its mechanism involves quicklime heating up when it comes into contact with water, burning the reed roots, and it requires a certain thickness to be effective. This method suffers from problems such as ineffectiveness before the roots grow upwards, high cost due to large amounts of quicklime used, and uneven ground deformation caused by the volume changes during quicklime hydration. Therefore, a single treatment method is insufficient to meet the needs of reed root treatment in airport pavement areas. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a foundation structure for treating reed roots in airport pavement areas. The foundation structure comprises an isolation layer, a partition layer, and a replacement layer. The isolation layer uses a composite geomembrane to prevent water from entering the partition layer prematurely, thus avoiding the deactivation of quicklime. It also isolates the reeds from air, sunlight, and herbicide leakage, cutting off root growth conditions and preventing groundwater pollution. The partition layer uses quicklime and herbicide; the quicklime reacts with water to generate heat and burn the roots, achieving physical killing, while the herbicide is absorbed by the roots for chemical killing. The two work synergistically to enhance the suppression efficiency. The partition layer and the isolation layer form a double barrier of chemical killing and physical barrier, effectively preventing roots from penetrating the pavement.

[0005] To achieve the above objectives, the following technical solution is adopted:

[0006] A foundation structure for treating reed roots in airport pavement areas includes an isolation layer, a partition layer, and a replacement layer distributed from bottom to top. The isolation layer is a composite geomembrane laid at the bottom, which includes stacked geomembranes and geotextiles. The partition layer is formed by laying a quicklime layer and a herbicide layer. The replacement layer is formed by laying replacement material. A pavement structure layer is laid on top of the replacement layer.

[0007] As a further preferred embodiment, the geotextile has multiple layers, with the geomembrane located between two layers of geotextile.

[0008] As a further preferred embodiment, the geotextile has three layers, with a geomembrane placed between every two layers of geotextile.

[0009] As a further preferred embodiment, the composite geomembrane is spliced ​​along the horizontal plane, and adjacent composite geomembranes overlap and seal at the splicing positions.

[0010] As a further preferred embodiment, the quicklime layer is made of quicklime powder, and the herbicide layer is made of chemical herbicide powder, with the herbicide layer formed by the chemical herbicide powder being located above the quicklime layer formed by the quicklime powder.

[0011] As a further preferred option, the replacement layer is made of sand, gravel, plain soil, lime soil, industrial waste and / or concrete.

[0012] As a further preferred embodiment, the thickness of the replacement pad layer is greater than the thickness of the partition layer.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] To address the issue of deep-rooted and resilient reeds in airport pavement areas, making it difficult to completely prevent them from penetrating the pavement structure with a single measure, a foundation structure consisting of an isolation layer, a barrier layer, and a replacement layer is adopted. The isolation layer uses a composite geomembrane to prevent water from entering the barrier layer in advance, thus avoiding the deactivation of quicklime. It also isolates air, sunlight, and herbicide leakage downwards, cutting off the conditions for root growth and preventing groundwater pollution. The barrier layer uses quicklime and herbicide. The quicklime heats up when it comes into contact with water, burning the roots for physical killing, while the herbicide is absorbed by the roots for chemical killing. The two work synergistically to improve the suppression efficiency. The barrier layer and the isolation layer form a double barrier of chemical killing and physical barrier, effectively preventing the roots from penetrating the pavement.

[0015] The geomembrane is made of multiple layers of geotextile. The geotextile provides tensile strength, while the geomembrane blocks water penetration, reduces the risk of tearing due to foundation settlement, and can reduce herbicide leakage, making it suitable for environmentally sensitive areas. Attached Figure Description

[0016] Figure 1This is a schematic diagram of the foundation structure used for treating reed roots in airport pavement areas according to an embodiment of this utility model.

[0017] Numbering explanation (in order of first appearance): 1. Pavement structure layer; 2. Isolation layer; 3. Separation layer; 4. Replacement layer. Detailed Implementation

[0018] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0019] When clearing reed roots beneath airport pavement areas, traditional deep-digging methods are labor-intensive and costly; herbicide-based methods require long-term testing and are prone to environmental pollution; and using quicklime alone for isolation has drawbacks such as premature failure, large dosage, and potential for foundation deformation. Reed roots are resilient, and a single measure cannot completely prevent them from penetrating the pavement structure. Therefore, this embodiment provides a foundation structure for treating reed roots in airport pavement areas. Isolation layer 3 uses quicklime and herbicide. Quicklime heats up upon contact with water, burning the roots, while the herbicide is absorbed by the roots for chemical elimination. The two work synergistically to enhance inhibition efficiency. A composite geomembrane prevents water from prematurely entering isolation layer 3, avoiding quicklime failure; it also isolates the area from air, sunlight, and herbicide leakage, cutting off root growth conditions and preventing groundwater pollution.

[0020] like Figure 1 As shown, the foundation structure used for treating reed roots in airport pavement areas adopts an isolation layer 2, a partition layer 3, and a replacement layer 4. By utilizing the barrier effect of the isolation layer 2 and the killing effect of the partition layer 3, it is not necessary to completely remove all reed roots; only the dense and robust root system on the surface needs to be removed, thus reducing the amount of excavation and replacement material.

[0021] The isolation layer 2, the partition layer 3, and the replacement layer 4 are distributed from bottom to top. The isolation layer 2 is laid at the bottom of the excavated foundation pit. The partition layer 3 and the replacement layer 4 are laid in sequence. The isolation layer 2 is a composite geomembrane laid at the bottom. The composite geomembrane includes stacked geomembranes and geotextiles. The partition layer 3 is formed by laying quicklime and herbicide layers in sequence. The replacement layer 4 is formed by laying replacement material. The pavement structure layer 1 is laid on top of the replacement layer 4.

[0022] During construction, firstly, based on the actual characteristics of the foundation soil and the depth of root growth, the soil layer containing relatively thick and dense reed roots is excavated to avoid uneven settlement of the foundation caused by root rot, and to prevent the compaction of the roadbed due to the presence of roots from failing to meet relevant requirements, which could endanger the safety of the upper pavement structure layer 1.

[0023] Then, after compacting the excavated surface, a composite geomembrane is laid as the isolation layer 2. This is mainly to play an isolation role. Upward, it can prevent water from entering the quicklime-herbicide-mixed barrier layer 3 in advance, preventing the quicklime from undergoing premature hydration and becoming ineffective. At the same time, the composite geomembrane has a certain tear resistance, which can block the upward growth of reed roots to a certain extent. Downward, it can isolate air and sunlight, cutting off the growth conditions necessary for the reed roots and limiting their growth rate. It can also prevent herbicides from seeping downward and polluting groundwater, thus meeting environmental protection requirements.

[0024] Next, the quicklime layer uses quicklime powder, and the herbicide layer uses a herbicide, such as chemical herbicide powder. The herbicide layer formed by the chemical herbicide powder is located above the quicklime layer formed by the quicklime powder. It is understandable that the quicklime powder and chemical herbicide powder can be pre-mixed to ensure the herbicide is evenly distributed in the quicklime. The quicklime layer and the herbicide layer form a barrier layer 3, primarily to prevent the reed roots from growing upwards. The quicklime generates heat upon contact with water, physically killing the reed roots that have grown to this layer, while the herbicide exerts its chemical killing effect. This dual physical and chemical action significantly improves the efficiency of killing and inhibiting the reed roots, effectively reducing the amount of quicklime used and saving on project costs.

[0025] Finally, the subbase is filled with qualified replacement filler material as required until the roadbed surface is reached, and then the pavement structure layer 1 is constructed.

[0026] like Figure 1 As shown, the composite geomembrane and the replacement layer 4 work together to constrain the volume expansion after the quicklime hydrates, reducing the risk of uneven settlement. The replacement layer 4 is compacted with qualified filler material to ensure the stable support of the pavement structure layer 1 and guarantee the safe operation of the airport. The type of composite geomembrane, the thickness of the partition layer 3, and the type of herbicide can be flexibly adjusted according to different geological conditions (such as groundwater level and soil type), making it suitable for the treatment of reeds and similar deep-rooted plants in various pavement foundations.

[0027] Geotextiles can be multi-layered, with a geomembrane positioned between two layers. The geotextiles are made of permeable fiber materials, while the geomembrane is made of impermeable materials such as HDPE. Taking a two-layer geotextile system as an example, the geotextile wraps around the geomembrane, forming a "permeable-impermeable-permeable" sandwich structure. The geotextile provides tensile strength (≥10kN / m), while the geomembrane blocks water infiltration (permeability coefficient ≤1×10-12cm / s), making it suitable for medium-load foundations.

[0028] In this embodiment, the geotextile has three layers, with a geomembrane placed between every two layers of geotextile, for a total of five layers. The double-layered geomembrane, reinforced with geotextile in the middle and on both sides, forms a five-layer structure of "permeable-impermeable-permeable-impermeable-permeable". The two-layered geomembrane structure enhances the resistance to root penetration and reduces herbicide leakage, making it suitable for environmentally sensitive areas.

[0029] When laying composite geomembranes, they are spliced ​​along the horizontal plane. Adjacent geomembranes overlap and seal at the splicing points. When using two layers of fabric and one layer of geomembrane, the overlap width at the edge should be ≥30cm; when using three layers of fabric and two layers of geomembrane, the overlap width at the edge should be ≥50cm. Double-seam hot-melt welding is used, and the weld peel strength should be ≥8N / cm. After splicing the composite geomembranes, the air tightness of the weld can be tested using an air-inflation method to ensure there are no leakage channels and to prevent the splices from becoming weak points for root penetration or chemical leakage.

[0030] In this embodiment, the herbicide layer is a herbicide product. The herbicide can be in powder or granular form. The herbicide should be a low-toxicity and easily degradable type, such as glyphosate powder, trifluralin powder, mefenoxam powder, chlorpyrifos granules, etc.

[0031] The quicklime layer uses quicklime powder, which is uniformly mixed with herbicide powder before being laid. The quicklime powder has a particle size of <2mm, a large specific surface area, and a faster temperature rise when it comes into contact with water, thus killing roots more quickly than lumpy quicklime. The mass ratio of quicklime powder to herbicide powder is 15:1-20:1. In other optional embodiments, other ratios can be used as needed.

[0032] Quicklime generates heat upon contact with water; the hydration reaction is CaO + H₂O = Ca(OH)₂. The purity of quicklime powder should be controlled to ≥85%.

[0033] In addition, by mixing quicklime powder with herbicides, the mixing ratio can be precisely controlled by metering equipment, avoiding localized failures caused by uneven mixing of traditional block quicklime and herbicide granules.

[0034] The thickness of the replacement layer 4 is greater than that of the partition layer 3. The partition layer 3 can be configured to be 5-10cm thick and mainly undertakes the root killing function. The replacement layer 4 can be configured to be 30-50cm thick, providing structural support through greater thickness and ensuring a compaction degree ≥96% to distribute the pavement load.

[0035] The replacement layer 4 can constrain the volume expansion of the quicklime after the partition layer 3 is hydrated, thus preventing the pavement from bulging due to the supporting force.

[0036] The replacement layer 4 is made of sand, gravel, plain soil, lime soil, industrial waste, and concrete.

[0037] Among them, the sand and gravel replacement layer 4 can be made of crushed stone, pebbles, coarse sand, medium sand, etc., and is suitable for shallow soft foundations and uneven foundation treatment, with good permeability and bearing capacity. Plain soil or lime-soil is often used to replace weak soil layers with a small thickness, and the foundation strength is improved by compaction. The replacement layer 4 can also be made of industrial waste such as slag and fly ash, which must meet environmental protection and strength requirements, and can reduce environmental pollution and lower costs. The replacement layer 4 can also be made of concrete, used in areas with high requirements for foundation bearing capacity, to form a rigid cushion layer.

[0038] In actual engineering projects, the selection of replacement material should be determined in combination with the site geological conditions, the depth of reed root distribution and engineering design requirements, so as to ensure that the replacement subbase 4 can effectively reduce uneven settlement and meet the pavement structure safety requirements.

[0039] The specific embodiments of the utility model have been described in detail above, but they are only examples, and the utility model is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications or substitutions to the utility model are also within the scope of the utility model. Therefore, all equivalent transformations, modifications, and improvements made without departing from the spirit and principles of the utility model should be covered within the scope of the utility model.

Claims

1. A foundation structure for treating reed roots in airport pavement areas, characterized in that, It includes an isolation layer, a partition layer, and a replacement layer distributed from bottom to top. The isolation layer is a composite geomembrane laid at the bottom, which includes stacked geomembranes and geotextiles. The partition layer is formed by laying a layer of quicklime and a layer of herbicide. The replacement layer is formed by laying replacement material. A pavement structure layer is laid on top of the replacement layer.

2. The foundation structure for treating reed roots in airport pavement areas as described in claim 1, characterized in that, The geotextile has multiple layers, with the geomembrane located between two layers of geotextile.

3. The foundation structure for treating reed roots in airport pavement areas as described in claim 2, characterized in that, The geotextile has three layers, with a geomembrane placed between every two layers of geotextile.

4. The foundation structure for treating reed roots in airport pavement areas as described in claim 1, 2, or 3, characterized in that, The composite geomembrane is spliced ​​along the horizontal plane, and adjacent composite geomembranes overlap and seal at the splicing positions.

5. The foundation structure for treating reed roots in airport pavement areas as described in claim 1, characterized in that, The quicklime layer is made of quicklime powder, and the herbicide layer is made of chemical herbicide powder. The herbicide layer formed by the chemical herbicide powder is located above the quicklime layer formed by the quicklime powder.

6. The foundation structure for treating reed roots in airport pavement areas as described in claim 1, characterized in that, The thickness of the replacement pad layer is greater than the thickness of the partition layer.

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