A rapid repair isolation membrane and water-permeable blind pipe collaborative laying equipment and method for constructing a plough layer - subsoil layer salt interception type plot

Abstract

This invention discloses a rapid remediation isolation membrane and permeable blind pipe laying equipment and method for constructing topsoil-subsoil salt-cutting plots, relating to the field of saline-alkali land improvement. It pioneers a non-excavation in-situ membrane laying technology, integrating modules such as a disc plow (2), a serrated separating plow (3), a soil conveying system (4), an HDPE geomembrane laying mechanism (5), and a permeable blind pipe laying device (6). The disc plow (2) cuts and shapes the field ridges (9), and the serrated separating plow (3) separates the topsoil layer (10) and subsoil layer (11). An HDPE geomembrane (12) is simultaneously laid and vertically attached to the ridges to form a three-dimensional barrel-shaped salt-cutting structure. Permeable blind pipes (13) are laid simultaneously, and soil amendments are added during backfilling. This invention completely blocks saltwater migration, solving the problems of recurring and costly traditional treatment methods, creating conditions for residual salt management and biological improvement, and is suitable for rapid remediation and topsoil reconstruction of saline-alkali land.

Description

Technical Field

[0001] This invention relates to the field of saline-alkali land improvement technology, specifically to a rapid repair isolation membrane and permeable blind pipe laying equipment and method for constructing topsoil-subsoil salt-cutting plots. Background Technology

[0002] Saline-alkali land management is a major challenge facing global sustainable agricultural development. Traditional management technologies mainly include flood irrigation to suppress salt, chemical treatment to reduce salt content, biological treatment, straw-based salt inhibition, and permeable underground pipe salt drainage. However, these technologies have consistently failed to overcome the core challenge of saltwater migration—saltwater has extremely high fluidity, and salt crystals in the subsoil layer 11 easily rise vertically to the cultivated layer 10 with water. At the same time, the field ridges 9, as soil connectivity carriers, can cause lateral salt infiltration, forming a comprehensive salt migration pathway.

[0003] The problem of salt migration directly leads to three fatal flaws in traditional technologies: First, the treatment effect is short-lived, and the improved topsoil layer 10 is prone to resalination, with a recurrence rate of over 60%; second, the treatment cost is high, requiring continuous investment of large amounts of water resources, chemical agents, and manpower, forming a vicious cycle of "treatment-salination-retreatment", with the cost of a single treatment being 3-5 times higher than that of this invention; third, it cannot be eradicated in one go, as existing technologies can only reduce the surface salinity of the topsoil layer 10 and cannot block the fundamental path of salt migration, resulting in the saline-alkali land being in a long-term dilemma of "treatment-rebound".

[0004] More importantly, the pervasiveness of saline migration makes existing biological improvement technologies ineffective—biological improvement relies on a stable soil salinity environment, while continuous saline migration disrupts the survival conditions of microbial communities, significantly reducing the improvement effect. Currently, there is no technological solution in the industry that can achieve full-dimensional salinity blocking, and the lack of integrated operational equipment restricts the large-scale and efficient development of saline-alkali land management. Therefore, cutting off saline migration paths is the core prerequisite and necessary condition for saline-alkali land management, and the key to overcoming existing technological bottlenecks. Summary of the Invention

[0005] I. Invention and Innovation Points

[0006] 1. Pioneering trenchless in-situ geomembrane laying technology: The innovative HDPE geomembrane laying mechanism 5 features a concealed installation scheme, integrating a membrane roll support shaft 51, a tension adjustment device 52, and a guide wheel 53. It is located behind the serrated separating plow blade 3 and below the soil conveying system 4. With the help of the equipment's walking power, the HDPE geomembrane 12 is laid in situ on the surface of the subsoil layer 11 without the need to excavate additional working pits, thus avoiding secondary damage to the soil structure. The tension adjustment device 52 can precisely control the membrane tension (0.1-0.3MPa), improving the flatness and deformation resistance of the membrane.

[0007] 2. Innovation of three-dimensional barrel-type salt interception structure: The three-dimensional barrel-type structure design of HDPE geomembrane 12 with "bottom laying + side application to the embankment" is proposed. The width of the membrane laying is 45-50cm wider than the excavation width. After being compacted by the wheel-type shaping device 7, it is vertically applied to the inside of the field embankment 9 to form a fully enclosed isolation space, which completely blocks the vertical migration and lateral infiltration of salt, and solves the drawback of traditional technology that can only block salt in one direction.

[0008] 3. Collaborative design innovation of "salt blocking-salt discharge-improvement-adaptation": The cultivated layer 10 generated by the three-dimensional barrel-shaped salt interception structure provides a closed environment for residual salt treatment. Combined with the permeable holes 131 of the permeable blind pipe 13 and the design of the outer geotextile 132, it realizes the directional collection of salt and prevents clogging. At the same time, the stable salt environment is more suitable for existing biological improvement technologies to play a role, forming a complete system of "physical barrier + functional synergy + technology adaptation".

[0009] 4. Integrated operation equipment innovation: It integrates functional modules such as soil cutting, layer separation, membrane laying, pipe laying, soil backfilling, and amendment addition. The membrane laying and pipe laying module achieves precise operation through components such as membrane roll support shaft 51 and positioning guide wheel 62. The daily operation area can reach 15 to 20 acres, which is 5 to 8 times more efficient than traditional decentralized processes. The HDPE geomembrane 12 has a design life of 50 years and can achieve a continuous salt interception effect for more than 40 years, which greatly reduces the long-term treatment cost.

[0010] II. Technical Solution

[0011] (I) Structure of Cooperative Laying Equipment

[0012] This equipment includes a traction unit 1, a soil cutting and separation module, a membrane laying and pipe laying module, a soil conveying and backfilling module, a soil improvement module, and a shaping module. All modules are connected via a mechanical transmission system, and the entire system is driven by power provided by the traction unit 1.

[0013] Towing Unit 1: It adopts a tractor or special towing machinery to provide the equipment with driving power and working traction force, and the driving speed can be adjusted according to the work requirements (0.5-1.2km / h).

[0014] Soil cutting and separation module:

[0015] Disc plow blade 2: Symmetrically set on both sides of the equipment, the spacing is adjusted according to the working width, the cutting depth is 45cm, used to standardize the width of the soil, separate the surrounding soil to reduce the resistance of subsequent digging, and form the foundation of the field ridge 9;

[0016] Serrated separating plow blade 3: Located 45-80cm behind the middle of the two disc plow blades 2, with an operating width consistent with the excavation width. The depth of penetration is adjusted via a hydraulic device. During horizontal movement, it separates the topsoil layer 10 from the subsoil layer 11 at a depth of 45cm, achieving complete separation of the upper and lower soil layers. 3. Film laying and pipe installation module:

[0017] HDPE geomembrane laying mechanism 5: Concealed behind the serrated separating plow blade 3 and below the soil conveying system 4, its core components include a membrane roll support shaft 51, a tension adjustment device 52, and guide wheels 53. The membrane roll support shaft 51 is used to fix the HDPE geomembrane 12 reel. The tension adjustment device 52 controls the release tension of the membrane (0.1-0.3MPa) through a spring damping structure. The guide wheels 53 ensure that the membrane is laid flat on the surface of the subsoil layer 11 in the horizontal direction. This mechanism pioneers trenchless in-situ membrane laying technology. By linking with the equipment's walking transmission mechanism, it achieves synchronous release and laying of the membrane, avoiding damage caused by geological deformation. The HDPE geomembrane 12 has a designed lifespan of 50 years, and its actual salt interception effectiveness can reach 40 years.

[0018] Permeable blind pipe laying device 6: Installed above the soil conveying system 4, the core components include a blind pipe support frame 61, a positioning guide wheel 62, and a release mechanism 63. The blind pipe support frame 61 is used to support the reel of the permeable blind pipe 13. The positioning guide wheel 62 restricts the deviation of the blind pipe through a groove design, with a positioning accuracy error of ≤5cm. The release mechanism 63 releases the blind pipe synchronously according to the equipment's travel speed, ensuring that the blind pipe is laid straight on the surface of the HDPE geomembrane 12. The permeable blind pipe 13 is an HDPE threaded perforated corrugated pipe with a ring stiffness of level 5, wrapped with geotextile (132) with a porosity of ≥30%. The pipe wall is evenly opened with permeable holes 131 with a diameter of 5-8mm. The permeable holes 131 are distributed in a plum blossom shape with an opening rate of ≥5%. It has three core functions:

[0019] Drainage and flood prevention: Quickly drain rainwater to prevent root rot caused by lack of oxygen in plant roots within the topsoil layer 10; Salt collection: Continuously collect dissolved salt crystals within the topsoil layer 10 and allow them to enter the pipe through the permeable holes 131 for directional salt discharge.

[0020] Ventilation and auxiliary functions: It delivers air and oxygen to the soil to meet the respiratory needs of plant roots. It can also deliver oxygen or oxygen-enriched water periodically to promote root growth and development or deliver ozone to prevent soil-borne diseases.

[0021] 4. Soil conveying and backfilling module: including soil conveying system 4 (including conveyor belt, drive roller and support frame), the conveyor belt receives the topsoil 10 shoveled by the sawtooth separating plow blade 3 and transports it backward to the area after the membrane is laid and pipes are laid, and backfills and covers the HDPE geomembrane 12 and the permeable blind pipe 13 to realize in-situ soil backfilling.

[0022] 5. Soil Improvement Module: This is a sealed hopper 8 located above the soil conveying system 4. It has an adjustable discharge port and a mixing device at the bottom. The hopper 8 is filled with bio-fertilizer and saline-alkali treatment agent. During the backfilling process, the discharge amount is automatically adjusted according to the amount of soil (50-100 kg / mu). The mixing device mixes the soil evenly to achieve in-situ improvement of the topsoil layer 10.

[0023] 6. Shaping Module: A wheel-type shaping device 7 symmetrically arranged at both ends of the membrane laying mechanism, including a compaction wheel and an angle adjustment mechanism. The compaction wheel rolls the extended part of the HDPE geomembrane 12, so that it is naturally and vertically attached to the inside of the field ridge 9, forming a regular three-dimensional barrel-shaped salt interception structure.

[0024] (II) Quick Repair Method

[0025] Using the aforementioned collaborative laying equipment, combined with pretreatment procedures, rapid restoration of saline-alkali land can be achieved. The specific steps are as follows:

[0026] Site pretreatment:

[0027] The area of ​​saline-alkali land was surveyed and demarcated, and independent treatment units of 20m×30m were divided and surface obstacles were removed.

[0028] Vertical plowing equipment is used to vertically till the soil in each unit to a depth of 45-50cm. During the tilling process, a salt and alkali control agent is sprayed simultaneously to break up compacted soil particles, increase the specific surface area, and ensure that the control agent is in full contact with the soil.

[0029] After rotary tillage, flood irrigation is carried out to suppress salt. Continue irrigation until the soil is saturated, and press the salt crystals in the tillage layer 10 into the subsoil layer 11. Let it stand for 3-5 days until the soil surface is slightly dry.

[0030] Integrated operation implementation:

[0031] The traction unit 1 drives the equipment into the treatment unit, adjusts the spacing of the disc plow blades 2 and the depth of the serrated separating plow blades 3, and starts the various functional modules.

[0032] During the movement of the equipment, the disc plow blade 2 cuts the soil to form the foundation of the field ridge 9, the serrated separating plow blade 3 separates the topsoil layer 10 from the subsoil layer 11, and the soil conveying system 4 collects the topsoil layer 10 and transports it backward.

[0033] Using trenchless in-situ membrane laying technology, the HDPE geomembrane laying mechanism 5 releases the HDPE geomembrane 12 through the membrane roll support shaft 51. The tension is controlled by the tension adjustment device 52 (0.1-0.3MPa). Under the action of the guide wheel 53, it is laid flat on the surface of the subsoil layer 11. The wheel-type shaping device 7 compacts the extended part of the membrane and applies it to the inside of the field ridge 9 in real time, forming a three-dimensional barrel-shaped salt interception structure. The cultivated layer 10 generated by this structure provides a closed and controllable environment for subsequent residual salt treatment. At the same time, the stable salt conditions are more suitable for existing biological improvement technologies to play a role, laying a solid foundation for the subsequent work of relevant enterprises.

[0034] The permeable blind pipe laying device 6 carries the blind pipe reel through the blind pipe support frame 61, and the positioning guide wheel 62 provides precise guidance. The release mechanism 63 releases the permeable blind pipe 13 simultaneously, laying it straight on the membrane surface and ensuring that the permeable holes 131 face the tillage layer 10. The soil conveying system 4 backfills and covers the tillage layer 10 soil carrying the amendment, completing the in-situ amendment. The equipment can achieve a daily operation efficiency of 15 to 20 acres, greatly improving the scale of treatment.

[0035] Post-treatment care and salt removal:

[0036] After backfilling, level the ground surface and lay drip irrigation pipe network and soil monitoring equipment;

[0037] Apply compound functional fertilizer solution every 15-20 days, and drip irrigate salt neutralization treatment agent every 30 days.

[0038] With the help of natural rainfall or artificial irrigation, the salt crystals remaining in the topsoil 10 dissolve, forming a salt-containing leachate. This leachate enters the pipe through the permeable holes 131 of the permeable blind pipe 13, is filtered by the outer geotextile 132, and is collected in a collection well. It is then pumped to the treatment system by a submersible pump. Routine maintenance of the permeable blind pipe 13: Every 3-6 months, a high-pressure backflushing device 14 is used to inject 0.3-0.5MPa high-pressure air or 0.2-0.4MPa high-pressure water flow into the permeable blind pipe 13. The backflushing principle is used to impact and remove the salt crystal dirt 15 attached to the permeable holes 131 and the outer geotextile 132, ensuring that the permeable blind pipe 13 is always in optimal working condition.

[0039] III. Beneficial Effects

[0040] Completely solve the problem of saltwater migration: The three-dimensional barrel-shaped salt interception structure achieves full-dimensional vertical and lateral salt isolation, and the HDPE geomembrane provides a continuous salt interception effect for 12 to 40 years, fundamentally preventing the re-salinization of the topsoil and reducing the recurrence rate to below 5%.

[0041] Significant advantages in operational efficiency and scale: The integrated equipment integrates precise components such as the membrane roll support shaft 51 and the positioning guide wheel 62, enabling it to operate on 15 to 20 acres per day. This is 5 to 8 times more efficient than traditional technologies, significantly reducing labor and time costs and meeting the needs of large-scale saline-alkali land treatment.

[0042] Multifunctional synergistic improvement effect: The permeable blind pipe 13 achieves multifunctional synergy of drainage, salt removal and aeration through the permeable hole 131 and the outer geotextile 132. Combined with in-situ soil improvement, the topsoil layer 10 can quickly reach the cultivation standard and the repair cycle is shortened to 1-2 months.

[0043] Adapted to existing biological improvement technologies: The stable salinity isolation environment provides a guarantee for the survival of the microbial community, improving the effectiveness of biological improvement technologies by more than 30%, and forming a synergistic effect.

[0044] Outstanding long-term economic benefits: A one-time investment enables 40 years of continuous salt interception, avoiding the high cost of repeated treatments using traditional technologies. The long-term treatment cost per acre is reduced by 60%-80%, making it suitable for large-scale restoration of various types of saline-alkali land. Attached Figure Description

[0045] Figure 1 Side view of the overall structure of the collaborative laying equipment

[0046] Figure 2 Top view of a three-dimensional barrel-shaped salt interception structure

[0047] Figure 3 Equipment operation process diagram

[0048] Figure 4 Enlarged view of the membrane laying and pipe installation module

[0049] Figure 5 Schematic diagram of permeable blind pipe structure and maintenance principle

[0050] Label Explanation

[0051] Figure 1 In the diagram, 1-traction unit, 2-disc plow blade, 3-serrated separating plow blade, 4-soil conveying system, 5-HDPE geomembrane laying mechanism, 6-permeable blind pipe laying device, 7-wheel shaping device, 8-hopper, 9-field ridge, 10-cultivated layer, 11-subsoil layer; the diagram clearly shows the positional relationship, connection method, and relative motion state of each module during operation, reflecting the integrated operation logic.

[0052] Figure 2 In the middle, 12-HDPE geomembrane, 13-permeable blind pipe, 10-reconstructed topsoil, 9-field ridge;

[0053] Figure 3In the process, S1 is the pretreatment process, S2 is the soil cutting and separation, S3 is the membrane laying and shaping, S4 is the pipe laying operation, S5 is the soil backfilling and improvement, and S6 is the post-salt removal and maintenance.

[0054] Figure 4 In the middle, 51-membrane roll support shaft, 52-tension adjustment device, 53-guide wheel, 61-blind tube support frame, 62-positioning guide wheel, 63-release mechanism, 4-soil conveying system, 11-core soil layer;

[0055] Figure 5 In the middle, 13-permeable blind pipe, 131 permeable hole, 132 outer geotextile, 14 high-pressure backflushing equipment, 15 salt crystal scale.

Claims

1. A rapid repair isolation membrane and permeable blind pipe co-laying equipment for constructing topsoil-subsoil salinity-cutting plots, characterized in that, It includes a traction unit (1), a soil cutting and separation module, a membrane laying and pipe laying module, a soil conveying and backfilling module, a soil improvement module, and a shaping module. All modules work together to achieve integrated operation. The soil cutting and separation module includes a symmetrically arranged disc plow (2) and a central serrated separation plow (3). The disc plow (2) has a cutting depth of 45cm and is used for standardized cutting of soil width and shaping of field ridges (9). The serrated separation plow (3) is adapted to an excavation width of 3-7m and has a depth of 45cm to achieve horizontal separation of the topsoil layer (10) and the subsoil layer (11). The membrane laying and pipe laying module includes an HDPE geomembrane laying mechanism (5) and a permeable blind pipe laying device (6). The HDPE geomembrane laying mechanism (5) is hidden below the soil conveying system (4) and has a built-in membrane roll support shaft (51), tension adjustment device (52) and guide wheel (53). The permeable blind pipe laying device (6) is located above the soil conveying system (4) and includes a blind pipe support frame (61), positioning guide wheel (62) and release mechanism (63). The two are linked synchronously with the equipment's walking power, pioneering a non-excavation in-situ membrane laying technology, which can complete the deep in-situ laying of HDPE geomembrane (12) without excavating additional working pits. The shaping module is a wheel-type shaping device (7), located at both ends of the membrane laying mechanism, used to vertically attach the extended part of the HDPE geomembrane (12) to the inside of the field ridge (9) to construct a three-dimensional barrel-type salt interception structure; The soil improvement module is a hopper (8) structure, located above the soil conveying system (4), used to add bio-fertilizer and saline-alkali treatment agent to the backfill soil.

2. The equipment according to claim 1, characterized in that, The HDPE geomembrane (12) has a thickness of 0.8-2.0 mm, and the upper and lower surfaces are composited with 300 g / ㎡ puncture-resistant non-woven fabric. Its laying width is 3-7 m wider than the working width of the sawtooth separating plow (3), and the size of the ridge (9) is reserved for the laying of the membrane. The permeable blind pipe (13) is an HDPE threaded corrugated pipe with a ring stiffness of 5, wrapped with geotextile (132), with a porosity ≥30%. The pipe wall has permeable holes (131) and has the functions of drainage and flood prevention, salt collection, ventilation and oxygen supply and auxiliary fertilization and disinfection. It can be maintained by injecting high-pressure air or high-pressure water flow through the high-pressure backflushing equipment (14) to remove salt crystal dirt (15) in the permeable holes (131).

3. The equipment according to claim 1, characterized in that, The soil conveying and backfilling module includes a soil conveying system (4) (including a conveyor belt, a drive roller and a support frame). The conveyor belt receives the topsoil (10) soil scooped up by the sawtooth separating plow (3) and transports it to the area after the film is laid and pipes are installed to complete the in-situ backfilling. During the conveying process, it is uniformly mixed with the amendment.

4. A rapid remediation method for constructing topsoil-subsoil salinity-cut-off plots, characterized in that, The equipment described in any one of claims 1-3 includes the following steps: S1: Pretreatment of saline-alkali soil: Vertical plowing equipment is used to vertically till the soil to a depth of 45-50cm, and saline-alkali treatment agent is mixed simultaneously. Then, large-scale irrigation is used to suppress salt, and the salt in the cultivated layer (10) is suppressed to the subsoil layer (11). S2: Soil cutting and layer separation. The soil is cut into standardized widths using the equipped disc plow (2) to form the foundation of the field ridge (9). The serrated separating plow (3) moves horizontally to a depth of 45cm to separate the cultivated layer (10) from the subsoil layer (11). S3: The three-dimensional barrel-shaped salt interception structure is constructed by using non-excavation in-situ membrane laying technology. The HDPE geomembrane laying mechanism (5) works in concert with the membrane roll support shaft (51), tension adjustment device (52) and guide wheel (53) to simultaneously lay the HDPE geomembrane (12) on the surface of the subsoil layer (11). Its extended part is squeezed and shaped by the wheel-type shaping device (7) and vertically attached to the inside of the field ridge (9) to form a three-dimensional barrel-shaped structure that is fully surrounded at the bottom and sides. The cultivated layer (10) generated by this structure provides the necessary conditions for subsequent residual salt treatment and is compatible with existing biological improvement technology. S4: The permeable blind pipe (13) is laid synchronously. The permeable blind pipe laying device (6) accurately lays the permeable blind pipe (13) on the preset position on the surface of the HDPE geomembrane (12) through the linkage of the blind pipe support frame (61), the positioning guide wheel (62) and the release mechanism (63), ensuring that the permeable hole (131) faces the cultivated layer (10). S5: Soil backfilling and in-situ improvement. The soil conveying system (4) backfills the separated topsoil (10) onto the HDPE geomembrane (12) and the permeable blind pipe (13). During the backfilling process, bio-fertilizer and saline-alkali treatment agent are added to the soil through the hopper (8). After being mixed evenly, the improved topsoil (10) is formed. S6: Salt leaching and post-maintenance: The residual salt crystals in the cultivated layer (10) are dissolved by natural rainfall or artificial irrigation and collected and discharged through the permeable holes (131) of the permeable blind pipe (13); 0.3-0.5MPa high-pressure air or 0.2-0.4MPa high-pressure water flow is injected into the permeable blind pipe (13) regularly using a high-pressure backflushing device (14) to remove the salt crystal dirt (15) in the permeable holes (131). At the same time, oxygen or oxygen-enriched water can be transported to the soil through the permeable blind pipe (13) to promote root growth and development. Ozone can also be transported to the soil to prevent soil-borne diseases.

5. The method according to claim 4, characterized in that, The purpose of vertical rotary tillage in step S1 is to break down the compacted soil structure, reorganize soil aggregates, and reduce soil resistance for subsequent equipment operations; the improved tillage layer (10) in step S5 meets the following requirements: pH value 6.0-7.5, organic matter content ≥15g / kg, cation exchange capacity ≥10cmol / kg, and bulk density 1.1-1.3g / cm³. 3 Technical specifications.

6. The method according to claim 4, characterized in that, In step S3, the HDPE geomembrane (12) automatically adjusts its flatness and ductility (tension range 0.1-0.3MPa) through the tension adjustment device (52) to avoid soil geological deformation from damaging the geomembrane; in step S4, the permeable blind pipe (13) is accurately laid out through the positioning guide wheel (62), with a positioning error ≤5cm.

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