Directional thin-wall injection type vertical barrier wall construction method

Abstract

The invention discloses a directional thin-wall injection type vertical barrier wall construction method which comprises the steps that bentonite-based slurry and complex suspension liquid are prepared, the complex suspension liquid comprises a ternary nanometer complex and water, and the mass ratio of the ternary nanometer complex to the water is 1: 20; tDS equipment is adopted for vertically cutting the soil body along the barrier construction position to form continuous cracks with the thickness of 5 cm, bentonite-based slurry and complex suspension liquid are synchronously injected into the continuous cracks to be solidified to form the underground barrier wall, the mixing amount of the complex suspension liquid is 1%-3%, and meanwhile a resistivity imager is adopted for monitoring the underground barrier wall to generate a permeation cloud picture; when the local area of the underground barrier wall is larger than 10 <-9 > m / s, a complex concentrated solution is prepared and injected in a reinforced mode, the complex concentrated solution comprises a ternary nano-composite and water, and the mass ratio of the ternary nano-composite to the water is 1: 10. The problems that a traditional underground pollution risk barrier wall is prone to deterioration, large in material consumption and low in construction efficiency are solved.

Description

Technical Field

[0001] The invention relates to the technical field of building construction, and in particular to a construction method of a directional thin-wall injection-type vertical barrier wall. Background Art

[0002] In the field of underground pollution risk control, traditional vertical barrier technologies such as the three-axis mixing pile method require excavation of the surface soil layer and foundation pit support. During the construction process, there are problems such as large earthwork transfer volume and high working space requirements (usually requiring ≥10m×10m equipment station space), which makes it difficult to meet the "zero shutdown" construction requirements of chemical parks. At the same time, the 30cm thick traditional barrier wall it constructs has the defects of large material consumption and low construction efficiency (a single device can only complete 13m per day), and the permeability coefficient of traditional cement-bentonite slurry is easily degraded to 10 in chemically polluted environments. -7 m / s or more, and cannot meet the demand for long-term resistance control.

[0003] While early high-pressure jet grouting technology enabled trenchless construction, it was primarily used for soft foundation reinforcement. Direct application for pollution barriers faced two major technical bottlenecks: First, the slurry's inadequate anti-pollution properties. Traditional bentonite-based slurries lacked the targeted adsorption capacity for heavy metal ions and VOCs, and relying solely on physical barrier construction could easily lead to the long-term migration and penetration of pollutants. Second, construction accuracy and monitoring methods lagged behind. Traditional processes employed a separate "construction-testing" model, failing to provide real-time feedback on wall continuity and creating blind spots for leakage risks. For example, after 2010, a chemical park constructed a barrier wall using traditional high-pressure jet grouting technology. One year after completion, testing revealed a 30% deterioration in local permeability, necessitating secondary reinforcement work and resulting in over 20% additional costs.

[0004] Furthermore, existing technologies are limited in their adaptability to complex strata. In densely populated areas with pipeline corridors, gravel beds, or exposed bedrock, traditional methods are prone to causing pipeline displacement or drill jamming, and are difficult to achieve high-precision construction of complex wall shapes such as curved paths. Therefore, developing a new barrier method that is low-disturbance, high-precision, and resistant to degradation has become a pressing technical challenge in the field of pollution prevention and control at industrial sites. Summary of the Invention

[0005] In order to overcome the defects of the existing technology, a directional thin-wall injection vertical barrier wall construction method is provided to solve the problems of easy deterioration, large material consumption and low construction efficiency of traditional underground pollution risk barrier walls.

[0006] To achieve the above objectives, a method for constructing a directional thin-wall injection-type vertical barrier wall is provided, comprising:

[0007] The following steps are involved:

[0008] Prepare a bentonite-based slurry and a composite suspension, wherein the composite suspension comprises a ternary nanocomposite and water, wherein the mass ratio of the ternary nanocomposite to the water is 1:20, and the ternary nanocomposite comprises magnesium-aluminum layered double hydroxide, graphite-like carbon nitride, and zeolite imidazolate framework-8;

[0009] A TDS device is used to vertically cut the soil along the barrier construction location to form a 5 cm thick continuous crack, and the bentonite base slurry and the composite suspension are simultaneously injected into the continuous crack to consolidate and form an underground barrier wall. The dosage of the composite suspension is 1-3%. At the same time, a resistivity imager is used to monitor the underground barrier wall to generate a permeability cloud map.

[0010] When the part of the underground barrier wall is greater than 10 -9 m / s, a composite concentrate is prepared and reinforced injected, wherein the composite concentrate comprises a ternary nanocomposite and water, and the mass ratio of the ternary nanocomposite to the water is 1:10.

[0011] Furthermore, the bentonite-based slurry includes bentonite, sand and water, and the mass ratio of the bentonite, the sand and the water is 10:100:40.

[0012] Furthermore, the overlapping width of adjacent walls of the underground barrier wall is ≥10 cm.

[0013] Furthermore, the dosage of the composite suspension in the arc-shaped section of the underground barrier wall is 3%.

[0014] Furthermore, the loading amount of the zeolite imidazolate framework-8 is ≥25%, and the specific surface area is ≥350m 2 / g.

[0015] Furthermore, before using TDS equipment to vertically cut the soil along the barrier construction location to form a 5cm thick continuous crack, it also includes using geological radar scanning, CPT static penetration and 5m interval layered sampling to generate a pollution risk classification map, and marking underground pipelines, high-concentration pollution areas and stratum permeability parameters.

[0016] The beneficial effect of this invention lies in its directional thin-wall injection-type vertical barrier wall construction method, which achieves low-disturbance and high-efficiency construction. Through trenchless high-pressure jetting technology, it addresses the "zero excavation, zero production downtime" construction requirements in production areas, compressing the equipment station space to 2m x 4m. The daily construction efficiency of a single device is increased to ≥20m, a speed increase of over 50% compared to traditional methods, and avoiding production disruptions such as pipeline corridor displacement and road closures caused by excavation.

[0017] The directional thin-wall injection-type vertical barrier wall construction method of the present invention realizes high-precision intelligent wall formation: it builds a "equipment-slurry-monitoring" collaborative system to achieve millimeter-level precision forming of 5cm thick thin-wall walls, and uses the ERT resistivity imager to generate a 10cm resolution permeability cloud map in real time, solving the quality blind spot of the traditional "construction-testing" separation, ensuring that the wall continuity reaches 100% and the permeability coefficient is stably controlled at ≤10 -9 m / s.

[0018] This invention's directional thin-walled injection-type vertical barrier construction method achieves long-term anti-pollution protection. The innovative introduction of ternary nanocomposite modification technology, through the synergistic effect of physical permeability (pore compression to less than 5nm) and chemical fixation (heavy metal adsorption capacity of 51mg / g), overcomes the bottleneck of traditional slurry anti-pollution degradation and achieves long-term control of pollutants such as heavy metals and VOCs (leaching rate ≤ 2%). DETAILED DESCRIPTION

[0019] The present invention will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention.

[0020] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the embodiments.

[0021] The present invention provides a method for constructing a directional thin-wall injection-type vertical barrier wall, comprising the following steps:

[0022] S1. Use geological radar scanning, CPT static penetration and 5m interval layer sampling to generate pollution risk classification map, and mark underground pipeline corridors, high concentration pollution areas and formation permeability parameters.

[0023] Specifically, 5m×5m grid geological radar scanning (scanning depth 30m), 20m interval CPT static penetration and 5m interval layered sampling were used to obtain the spatial distribution of the pollution plume and the permeability parameters of the formation (permeability coefficient 10 -6 ~10 -3 cm / s) and the location of underground pipe corridors to generate a "Pollution Risk Grading Map", using red, yellow and green colors to indicate pollution risk levels (pollutant concentration in high-risk areas is >100mg / L), providing a basis for the differentiated design of barrier walls.

[0024] S2. Prepare a bentonite-based slurry and a composite suspension, wherein the composite suspension includes a ternary nanocomposite and water, wherein the mass ratio of the ternary nanocomposite to water is 1:20, and the ternary nanocomposite includes magnesium aluminum layered double hydroxide (Mg-AlLDH), graphite-like carbon nitride (g-C3N4) and zeolite imidazolate framework-8 (ZIF-8).

[0025] The preparation of bentonite-based slurry includes dry mixing bentonite and sand at a ratio of 10:100, adding water to a moisture content of 40%, and stirring for 30 minutes.

[0026] The preparation of the composite suspension includes mixing the ternary nanocomposite and water in a mass ratio of 1:20, and dispersing the mixture by 300W ultrasound until the sedimentation rate is ≤1% / h.

[0027] When the ground is abnormal, add a quick-setting agent (sodium silicate solution, modulus 3.2) at a volume of 3% to 5% of the bentonite-based slurry, and the initial setting time should be ≤30 minutes.

[0028] In this embodiment, the ternary nanocomposite is a Mg-Al LDH / g-C3N4 / ZIF-8 composite, wherein, based on the mass percentage of the ternary nanocomposite, the ternary nanocomposite comprises 50% to 65% of Mg-Al LDH, 25% to 35% of g-C3N4, and 10% to 15% of ZIF-8.

[0029] As a preferred embodiment, the loading amount of ZIF-8 is ≥25%, and the specific surface area is ≥350m 2 / g.

[0030] As a preferred embodiment, the optimal slurry ratio is determined through penetration test, adsorption test and leaching toxicity test.

[0031] Penetration test: 150mg / L Cr 6+ The solution is used as the medium and the permeability coefficient is tested for 28 days and is required to be constant ≤1×10 -9 m / s;

[0032] Adsorption test: exposed to 500ppm VOCs mixed gas for 72 hours, saturated adsorption capacity ≥30mg / g;

[0033] Leaching toxicity test: Leaching in an acid-base alternating environment with a pH of 3 to 11 for 90 days, the pollutant leaching rate is ≤2%;

[0034] Parameter optimization: Through the dosage gradient test of the ternary nanocomposite (1%, 2%, 3%), a "Slurry Ratio Verification Report" was formed.

[0035] S3. Use TDS equipment to vertically cut the soil along the barrier construction location to form 5 cm thick continuous cracks, and simultaneously inject bentonite base slurry and composite suspension into the continuous cracks to consolidate and form an underground barrier wall. The dosage of composite suspension is 1-3%. At the same time, a resistivity imager is used to monitor the underground barrier wall to generate a permeability cloud map.

[0036] Before the formal injection construction, verify the equipment construction accuracy and system reliability.

[0037] High-pressure jet: working pressure 20MPa, nozzle diameter Φ45mm, pressure fluctuation controlled within ±5%;

[0038] Grouting parameters: bentonite-based slurry flow rate 12 ± 0.5 L / min, composite suspension flow rate 3 ± 0.2 L / min;

[0039] Verticality: Deviation ≤ 1‰, monitored throughout by inclinometer;

[0040] Performance verification: Take three core samples of the wall every 100 meters and test the permeability coefficient (≤10 -9 m / s) and Cr 6+ Adsorption capacity (≥25mg / g), formal construction can only be carried out after the compliance rate reaches 100%.

[0041] During the formal injection construction, directional cutting uses GPS-RTK positioning (horizontal error ≤ 2cm, elevation error ≤ 5cm), and vertically cuts the soil at a speed of 0.8m / min, forming a 5cm thick continuous crack with a depth error of ±0.3m and a safe distance from underground pipelines >1m.

[0042] Dual-channel synchronous grouting:

[0043]

[0044] In this embodiment, the bentonite-based slurry includes bentonite, sand and water, and the mass ratio of bentonite, sand and water is 10:100:40.

[0045] Wall joints: Adjacent walls overlap ≥10cm, using a backward grouting process. For curved sections (radius of curvature ≥3m), the nanocomposite content is increased to 3%.

[0046] Grouting uses the TDS injection main unit (TDS-200S), with technical parameters: jet pressure 20MPa, positioning accuracy ±2cm, equipped with a dual hydraulic pump redundancy system (failure switching ≤10 seconds), and support for arc path construction (curvature radius ≥3m);

[0047] Function integration: integrated operation of high-pressure water jet cutting (nozzle Φ45mm) and dual-channel grouting.

[0048] The slurry circulation system includes a cyclone separator and a negative pressure feeding device.

[0049] The solid phase recovery rate of the cyclone separator is ≥95%, and the waste pulp conversion rate is <0.5m 3 / 100m, the pH of the separated water is adjusted to 6.5-7.5 and then reused.

[0050] The dust concentration of nanomaterial feeding in negative pressure feeding device is ≤1mg / m3 , in line with GBZ 2.1 standard.

[0051] S4, when the local underground barrier wall> 10 -9 m / s, a composite concentrate is prepared and reinforced and injected, the composite concentrate comprises a ternary nanocomposite and water, and the mass ratio of the ternary nanocomposite to water is 1:10.

[0052] Specifically, every time the wall advances 2 meters, an ERT resistivity imager generates a 10cm resolution permeability cloud map to monitor the wall continuity (mutation <5%) and grouting uniformity (density difference <5%). Automatic grouting is carried out and composite concentrate (composite: water = 1:10) is injected until the standard is met.

[0053] While monitoring the wall in real time, an explosion-proof PID detector (detection limit 0.1ppm) is integrated to monitor the concentration of combustible gas. When the combustible gas concentration is greater than 10% LEL, the jet flow is automatically cut off and the explosion-proof ventilation system is activated.

[0054] The ERT resistivity imager (ERT-Pro) generates 10 cm resolution permeability cloud maps in real time, with a data feedback delay of ≤ 2 minutes.

[0055] Explosion-proof PID detector (GasPro-D5): detection limit 0.1ppm, linked with the jet system, automatically starts emergency ventilation when the combustible gas concentration is greater than 25% LEL (air volume ≥ 5000m 3 / h).

[0056] Finally, physical inspection is carried out for quality acceptance. Specifically, Φ100mm core samples are drilled every 50 meters to test the permeability coefficient (ASTM D5084 standard, ≤10 -9 m / s) and Cr 6+ Adsorption capacity (≥25mg / g); ground penetrating radar scanning wall thickness (5cm±5mm), leaching toxicity test (HJ 557 standard, 28-day leaching rate ≤2%).

[0057] The directional thin-wall injection vertical barrier wall construction method of the present invention is suitable for complex scenarios, such as:

[0058] Ground pretreatment: Before construction on pebble or hard ground, use pre-grouting (cement-water glass double liquid slurry) or sodium pyrophosphate solution (0.5‰ concentration) to soften the soil;

[0059] Sensitive area control: When adjacent to a water body, the wall depth extends to 1-2 meters below the aquifer floor, using a continuous thin-wall structure;

[0060] Risk management: Inject quick-setting slurry (initial setting < 30 minutes) when the cavity collapses; pull back the drill rod and pre-grout to soften it when the drill is stuck in hard formations.

[0061] The directional thin-wall injection vertical barrier wall construction method of the present invention realizes "zero excavation, high precision, and long life" pollution barrier through the technical integration of high-pressure jet precise wall formation, nanomaterial multi-mechanism barrier control and intelligent system closed-loop control, solving the contradiction between construction and production in chemical parks, and is suitable for the prevention and control of heavy metal, VOCs and NAPLs pollution in permeable strata such as silt and sand.

[0062] The directional thin-wall injection-type vertical barrier wall construction method of the present invention breaks through the performance bottleneck of traditional barrier construction methods through technology integration and material innovation. It shows significant advantages in construction efficiency, environmental friendliness, long-term barrier effect, and adaptability to complex scenarios. The specific beneficial effects are as follows:

[0063] 1. High-efficiency and low-disturbance construction to ensure production continuity.

[0064] (1) Trenchless operation.

[0065] There is no need for surface excavation and foundation pit support, and the equipment station space only needs 2m×4m, avoiding the problems of pipeline displacement and road closure caused by excavation in traditional methods, and realizing "zero shutdown" construction in the chemical park. A single project can ensure that the output value of approximately 250 million yuan will not be interrupted.

[0066] (2) Efficiency is significantly improved.

[0067] A single TDS injection unit can complete the construction of a barrier wall ≥20m per day, which is 54% faster than the traditional three-axis mixing pile method (13m / day), shortens the overall construction period by more than 50%, and saves 35% in labor and equipment costs.

[0068] 2. Intelligent and precise wall formation to ensure barrier reliability.

[0069] (1) Millimeter-level construction accuracy.

[0070] A 5cm thick thin-walled wall is constructed, which is 80% thinner than the traditional process (30cm). Through the "equipment-slurry-monitoring" collaborative system, precise control of verticality deviation ≤1‰ and positioning error ≤2cm is achieved.

[0071] (2) Real-time quality closed loop.

[0072] The ERT resistivity imager generates a 10cm resolution permeability cloud map every 2m, and monitors the permeability coefficient in real time (stable ≤10 - 9 m / s), inspection and construction are carried out simultaneously, eliminating the quality blind spots of traditional "construction-inspection" separation, and the wall continuity reaches 100%.

[0073] 3. Nano-modification resistance control breaks through the bottleneck of long-term effectiveness.

[0074] (1) Multiple mechanisms for coordinated prevention and control.

[0075] The ternary nanocomposite material has a dual effect of physical permeability resistance (pore compression to less than 5nm) and chemical fixation (heavy metal adsorption capacity 51mg / g), which makes the wall permeability coefficient stable ≤10 in polluted environment. -9 m / s, pollutant leaching rate ≤2%, and the anti-deterioration ability is more than 3 times higher than that of traditional bentonite-based slurry.

[0076] ZIF-8 micropores fill the gaps between bentonite particles, compressing the average pore size from 50nm to below 5nm, forming a "molecular sieve" structure to intercept large pollutant molecules and achieve physical permeation resistance.

[0077] NO3 between Mg-Al LDH layers - Ion exchange with anionic pollutants, Zn of ZIF-8 2+ The nodes are coordinated with the oxygen-containing functional groups of VOCs, and the g-C3N4 aromatic ring adsorbs non-polar organic matter through π-π interaction. The heavy metal adsorption capacity reaches 51 mg / g, achieving chemical fixation.

[0078] (2) Efficient use of materials.

[0079] The targeted adsorption characteristics of the nanocomposite increase the material utilization rate to 95%, reducing resource consumption by 70% compared to traditional activated carbon walls. At the same time, the bentonite-based slurry is recycled through a cyclone separator (solid phase recovery rate ≥ 95%), saving more than 800 tons of natural mineral resources in a single project.

[0080] 4. Green and low-carbon technology to reduce environmental load

[0081] (1) Pollution prevention and control throughout the entire process.

[0082] Closed slurry circulation system makes waste slurry conversion rate less than 0.5m 3 / 100m, which is 90% less than the traditional method; the nanometer feeding negative pressure dust removal system makes the dust concentration in the working area ≤1mg / m 3 , VOCs monitoring and explosion-proof systems are linked to cut off the jet to avoid secondary pollution during the construction period.

[0083] (2) Significant low-carbon and energy-saving effects.

[0084] The TDS main engine is fully electrically driven, replacing the diesel engine. This reduces diesel consumption by 15.8 tons per 10,000 linear meters, equivalent to a CO2 emission reduction of 42 tons (equivalent to planting 2,300 trees). The wall thickness is reduced by 80%, the material usage is reduced by 80%, and the cost per kilometer is reduced from 10.67 million yuan to 6.4 million yuan, with the full life cycle cost reduced by more than 60%.

[0085] 5. Adapt to complex scenarios and expand application boundaries.

[0086] (1) Strong adaptability to the formation. Applicable to permeability coefficient 10 -6 ~10 -3 The silt and sandy soil layers with a speed of cm / s can be extended to the pebble layer through pre-grouting improvement; the construction depth is ≤20m (if exceeding, a drill rod stabilization system is configured), which meets the pollution barrier needs of most chemical parks.

[0087] (2) Special scene technology.

[0088] Curved path construction (radius of curvature ≥ 3m) and interlocking joints (overlap width ≥ 10cm) are suitable for densely populated pipeline corridors and complex tank areas. When adjacent to sensitive water bodies, the wall extends below the aquifer floor to form a fully enclosed anti-seepage barrier.

[0089] Through the coordinated optimization of "technological innovation-efficiency improvement-environmental friendliness", this invention has formed a set of "economically efficient, intelligent, precise, green and long-lasting" pollution barrier solutions, providing a breakthrough technical path for pollution prevention and control in industrial sites, with significant social, economic and environmental benefits.

[0090] In order to further illustrate the beneficial effects of the directional thin-wall injection-type vertical barrier wall construction method of the present invention, the following embodiments are given for detailed description.

[0091] Example 1

[0092] 1. Project Overview:

[0093] Heavy metals (Cr 6+ ) pollution, and the pollution plume is distributed in the silt sand layer 3 to 18 m below the surface (permeability coefficient 8×10 -4 cm / s), with a peak concentration of 120 mg / L. The site is located adjacent to the factory's oil and stormwater pipelines, requiring uninterrupted production operations during construction. Traditional excavation-based containment techniques were eliminated due to their high disturbance and long construction time. The method presented in this paper was then used to implement pollution containment.

[0094] 2. Implementation steps:

[0095] (1) Three-dimensional geological exploration.

[0096] Use 5m×5m grid geological radar scanning to identify underground pipeline corridor locations and high-risk pollution areas (Cr 6+ >100 mg / L), combined with CPT static penetration test at 20 m intervals, the average permeability coefficient of the formation was determined to be 6.5×10 -4 cm / s, and the depth of the pollution plume core area is 5 to 15 meters.

[0097] Output the "Pollution Risk Grading Map". The red high-risk area accounts for 25% of the area and requires a continuous thin-walled wall structure; the yellow transition area uses a grid wall with a wall spacing of 1.5m.

[0098] (2) Serum compatibility test.

[0099] Targeting Cr 6+ The gradient test determined that the content of the ternary nanocomposite was 2%, at which point the permeability coefficient of the bentonite-based slurry stabilized to 7×10 -10 m / s, Cr 6+ The adsorption capacity reaches 50 mg / g, and the 90-day leaching toxicity test leaching rate is 1.6%, meeting the HJ557 standard.

[0100] (3) TDS equipment test pile verification.

[0101] The test pile depth is 20m (maximum construction depth), the jet pressure is 20MPa, the nozzle is Φ45mm, and the base slurry (flow rate 12L / min) and the composite suspension (flow rate 3L / min) are injected simultaneously.

[0102] The core sampling test showed that the wall permeability coefficient was 5×10 -10 m / s, verticality deviation 0.6‰, positioning error 1.8cm, which meets the requirements of the "Technical Specifications for Vertical Barriers" (T / CAEPI 28-2021).

[0103] (4) Formal injection construction.

[0104] The GPS-RTK system was used to avoid underground pipelines (safety distance > 1.2m), and the soil was cut at a speed of 0.8m / min, forming 5cm thick cracks with a depth error of ±0.2m. The total length of the barrier wall constructed was 300m (200m of continuous wall and 100m of grid wall).

[0105] Double-channel grouting, base slurry pressure 0.4MPa, composite pressure 0.3MPa, trigger ERT scanning every 2m in the red high-risk area, local permeability exceeding the standard area (1.2×10 -9 m / s) automatic grouting complex concentrate (1:10 ratio) until the data meets the standard.

[0106] The overlapping width of adjacent walls is 12 cm. When crossing the curved section of the oil pipeline (curvature radius 3.5 m), the composite content is increased to 3%. The average daily construction distance of a single device is 21 m, and the total construction period is 15 days.

[0107] (5) Environmental risk control.

[0108] The solid phase recovery rate of the cyclone separator is 96%, and the amount of waste slurry generated is 12m 3 (The traditional method is about 120m 3), the separated water is fully reused after pH adjustment; the negative pressure dust removal system makes the dust concentration in the working area 0.9mg / m 3 The PID detector did not detect any combustible gas exceeding the standard, achieving "zero pollution emission" during the construction period.

[0109] 3. Quality acceptance and effect:

[0110] (1) Entity detection.

[0111] Φ100mm core samples were drilled every 50m, with a total of 6 groups, and the average permeability coefficient was 6×10 -10 m / s, Cr 6+ The average adsorption capacity was 27 mg / g, which was better than the design standard. The ground penetrating radar scan showed that the wall thickness was 4.7 to 5.3 cm, with a deviation of ±3 mm. The leaching toxicity test showed that Cr 6+ The leaching rate is 1.3%, which meets the requirements of the "Technical Guidelines for Groundwater Remediation in Contaminated Land" (HJ 25.6-2019).

[0112] (2) Long-term monitoring.

[0113] Three and six months after the completion of construction, groundwater was monitored and the downstream monitoring well Cr 6+ The concentration was stabilized at 0.04 mg / L (national standard limit 0.1 mg / L), and the migration of the pollution plume was completely blocked; the factory production line operation data showed that the equipment vibration value during the construction period was less than 5 mm / s, which did not cause any interference to production and achieved the "zero shutdown" goal.

[0114] 4. Benefit comparison:

[0115] Comparison items The method of the present invention Traditional high-pressure jet grouting method Improvement effect Construction efficiency 21m / day 12m / day 75% increase Wall thickness 5cm 20cm 75% thinning Material costs 1.92 million yuan (300m) 4.8 million yuan 60% reduction <![CDATA[CO2 emissions]]> 4.8 tons 17.6 tons 73% reduction in emissions Production capacity guarantee Zero downtime Production needs to be suspended for 15 days Directly avoided losses of approximately 40 million yuan

[0116] The directional thin-wall injection-type vertical barrier wall construction method of the present invention achieves high-precision, low-disturbance construction in a complex pipeline environment through the coordinated application of intelligent monitoring and nano-modification technology, effectively resolving the contradiction between pollution prevention and control and production supply guarantee in the production park, verifying its technological advancement and engineering practicality, and providing a standardized solution for similar high-risk pollution sites.

[0117] The above description is merely a preferred embodiment of the present application and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the invention herein is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the inventive concept. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features having similar functions disclosed in this application.

Claims

1. A method for constructing a directional thin-wall injection-type vertical barrier wall, characterized in that: The following steps are involved: Prepare a bentonite-based slurry and a composite suspension, wherein the composite suspension comprises a ternary nanocomposite and water, wherein the mass ratio of the ternary nanocomposite to the water is 1:20, and the ternary nanocomposite comprises magnesium-aluminum layered double hydroxide, graphite-like carbon nitride, and zeolite imidazolate framework-8; A TDS device is used to vertically cut the soil along the barrier construction location to form a 5 cm thick continuous crack, and the bentonite base slurry and the composite suspension are simultaneously injected into the continuous crack to consolidate and form an underground barrier wall. The dosage of the composite suspension is 1-3%. At the same time, a resistivity imager is used to monitor the underground barrier wall to generate a permeability cloud map. When the part of the underground barrier wall is greater than 10 -9 m / s, a composite concentrate is prepared and reinforced injected, wherein the composite concentrate comprises a ternary nanocomposite and water, and the mass ratio of the ternary nanocomposite to the water is 1:

10.

2. The method for constructing a directional thin-wall injection-type vertical barrier wall according to claim 1, characterized in that: The bentonite-based slurry includes bentonite, sand and water, and the mass ratio of the bentonite, the sand and the water is 10:100:

40.

3. The method for constructing a directional thin-wall injection-type vertical barrier wall according to claim 1, characterized in that: The overlapping width of adjacent walls of the underground barrier wall is ≥10 cm.

4. The method for constructing a directional thin-wall injection-type vertical barrier wall according to claim 3, characterized in that: The dosage of the composite suspension of the arc-shaped section of the underground barrier wall is 3%.

5. The method for constructing a directional thin-wall injection-type vertical barrier wall according to claim 1, characterized in that: The loading amount of the zeolite imidazolate framework-8 is ≥25%, and the specific surface area is ≥350m 2 / g.

6. The method for constructing a directional thin-wall injection-type vertical barrier wall according to claim 1, characterized in that: It also includes the use of geological radar scanning, CPT static penetration and 5m interval layered sampling to generate a pollution risk classification map before using TDS equipment to vertically cut the soil along the barrier construction location to form a 5cm thick continuous crack, and mark the underground pipeline corridor, high-concentration pollution area and formation permeability parameters.

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