Super-large-area deep foundation pit nerve conduction type dewatering and drainage system and technology

Abstract

The invention discloses an ultra-large-area deep foundation pit nerve conduction type dewatering and drainage system and technology, and relates to the technical field of drainage systems. Comprising a water interception system arranged on the periphery of the deep foundation pit, a pit top drainage ditch arranged on the periphery of the water interception system, a plurality of dewatering wells evenly arranged in the deep foundation pit, a nerve conduction type dewatering and drainage collecting assembly communicating with the dewatering wells and the pit top drainage ditch, and a main water outlet pipe drainage channel communicating with the pit top drainage ditch. The multi-stage sedimentation tank is communicated with the main water outlet pipe drainage channel, the ozone reaction system is communicated with the multi-stage sedimentation tank, the flow channel is communicated with the ozone reaction system, the buffer tank is communicated with the flow channel, and the water quality and water level online monitoring system is arranged in the flow channel. The multi-stage sedimentation tank is respectively matched with the physical purification equipment, the biological purification device and the chemical purification equipment; the outlet of the buffer pool is divided into two pipelines, one pipeline is communicated with the water storage tank, and the other pipeline is communicated with the wetland water replenishing system through a water replenishing pipeline; the nerve conduction type drainage method is adopted, the number of high-lift water pumps and drainage pipelines are greatly reduced, the online monitoring and detection system is adopted for precise control, and electricity consumption is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of drainage system technology, and more specifically to the field of neural conduction drainage system and process technology for ultra-large area deep foundation pits. Background Technology

[0002] A water-stop curtain is used to block external water inflow. Dewatering wells are installed at regular intervals within the foundation pit. Pumps and pipes are installed in these wells to drain the water. The pipes extend directly to a drainage ditch outside the foundation pit. The water is collected in the drainage ditch and then flows into a three-stage sedimentation tank on the construction site. After preliminary sedimentation treatment, the water is discharged into the municipal sewage network. The existing technology has the following drawbacks: 1. The commonly used water-stopping curtains are mainly high-pressure jet grouting piles, deep mixing piles, and cement-soil mixing piles. These types of water-stopping curtains have poor applicability under similar hydrogeological conditions such as the Dianchi Lake Basin, and cannot meet the function of blocking external water in ultra-large area deep foundation pits.

[0003] 2. The traditional method of using dewatering wells to lay pipelines means that dewatering and excavation of the foundation pit cannot be carried out simultaneously, which severely restricts the efficiency of both dewatering and excavation.

[0004] 3. It is impossible to observe and control the water level in the foundation pit in a timely manner, and the water level control is entirely dependent on manual measurement, which results in a large waste of manpower and material resources.

[0005] 4. The drainage ditch on the top of the pit is only used for intercepting and draining water, and the sedimentation tank is only used for coarse treatment and sedimentation. Its functions are limited and it does not play a role in auxiliary purification and water quality control.

[0006] 5. Water from the foundation pit, construction water, and rainwater are directly discharged into the municipal sewage network, increasing the burden on the municipal sewage network and sewage treatment plants.

[0007] 6. Water quality testing relies on traditional manual testing, which is inefficient and has poor control effects.

[0008] 7. Failed to truly achieve water conservation, sustainable use, and recycling. Summary of the Invention

[0009] The purpose of this invention is to solve the above-mentioned technical problems by providing a neural conduction-type dewatering system and process for ultra-large area deep foundation pits.

[0010] To achieve the above objectives, the present invention specifically adopts the following technical solution: One aspect of the present invention provides a neural conduction-type dewatering system for ultra-large area deep foundation pits, including a water interception system set outside the deep foundation pit, a pit top drainage ditch set outside the water interception system, a plurality of dewatering wells evenly arranged in the deep foundation pit, a neural conduction-type dewatering collection component connected to the plurality of dewatering wells and the pit top drainage ditch respectively, a main outlet pipe and drainage channel connected to the pit top drainage ditch, a multi-stage sedimentation tank connected to the main outlet pipe and drainage ditch, an ozone reaction system connected to the multi-stage sedimentation tank, a flow channel connected to the ozone reaction system, a buffer tank connected to the flow channel, and an online water quality and water level monitoring system set in the flow channel; Multi-stage sedimentation tanks are used in conjunction with physical purification equipment, biological purification devices, and chemical purification equipment, respectively. The outlet of the buffer pool is divided into two pipelines. One pipeline is connected to the storage tank, and the other pipeline is connected to the wetland water replenishment system through the water replenishment pipeline.

[0011] Specifically, this plan uses "interception-type precipitation" and "nerve conduction-type drainage" as measures, and organically combines "interception, prevention, reduction, and drainage" measures for treating groundwater inflow through "physical purification + biological purification + chemical purification". It is supplemented by information technology means such as automated water level monitoring and water quality monitoring to achieve the effect of dewatering during foundation pit excavation. At the same time, by comprehensively utilizing the tailwater and replenishing the surrounding wetlands, it improves the sustainable use of non-traditional water sources and reduces groundwater waste and impact on the surrounding environment.

[0012] Two 60m³ water storage tanks are installed on site, with a total storage capacity of 120m³, which can meet the water needs for construction and production such as spraying, dust suppression, greening spraying, and concrete curing. The treated wastewater that meets the standards is pumped by a 7.5KW water pump in the buffer pool and then supplied to the wetland water inlet through the D160 drainage pipe. A buffer screen is installed at the wetland water inlet to prevent water erosion around the inlet.

[0013] In one embodiment, the neural conduction type downwater collection assembly includes a plurality of evenly distributed downwater wells and a plurality of evenly distributed collection tanks. For dewatering wells located ≤50m from the edge of the deep foundation pit, the extracted groundwater is directly pumped into the drainage ditch at the top of the pit. Multiple dewatering wells and several collection tanks located more than 50m from the edge of the deep foundation pit constitute multiple neural conduction dewatering units centered on each collection tank. Each neural conduction dewatering unit includes multiple dewatering wells and a collection tank located in the middle of the multiple dewatering wells. All dewatering wells in the same neural conduction dewatering unit are collected into the corresponding collection tank through branch drainage pipes. Each collection tank is connected to the drainage ditch on the top of the pit through the main drainage pipe. Several dewatering wells are arranged in an equilateral triangle at a set interval, and the distance from all dewatering wells to the corresponding collection tank within the same nerve conduction dewatering unit is less than 50m.

[0014] Specifically, the dewatering wells within the pit are constructed according to the following process: "construction preparation → dewatering well drilling → final drilling → well casing installation → backfilling with medium-coarse sand → mud sealing → well washing and pumping." The wells use 700mm diameter, 273mm diameter bridge-type filter pipes, with a depth of 25-35m, arranged in an equilateral triangle pattern at 20m intervals, and constructed from the ground. Before officially commencing dewatering, the elevation of each wellhead and the ground surface are measured, the stable water level is determined, and pumping equipment, water level monitoring equipment, cables, and drainage channels are arranged to ensure the normal operation of the entire dewatering system.

[0015] Groundwater extracted from the central area of ​​the foundation pit (more than 50m from the edge) is collected in a nearby water collection tank. The tank measures 2.4m × 1.6m × 1.5m (length × width × height) and has a maximum storage capacity of 5.76m³. The water is then pumped to the drainage ditch at the top of the pit, preventing infiltration and ensuring effective dewatering. This also reduces the number of exit pipes, minimizing the impact on earthwork excavation. Groundwater extracted from the periphery of the deep foundation pit (≤50m from the edge) is directly pumped to the drainage ditch at the top of the pit.

[0016] After the foundation pits were excavated to the design elevation of the base at the junctions of the pits within the pits, the boundaries of each storage block, and the elevation range of the impermeable layer, a neural network filter system with first to third-stage blind pipes was installed at the junctions to fully collect scattered water and rainwater within the pits. The blind pipes were made of HDPE rigid permeable pipes, and the trenches were trapezoidal, backfilled with medium to coarse sand. The first-stage blind pipes had a diameter of 300mm and a trench size of 600mm×600mm; the second-stage blind pipes had a diameter of 150mm and a trench size of 300mm×300mm; and the third-stage blind trench had no blind pipes and a trench size of 300mm×300mm.

[0017] In one embodiment, the cross-section of the drainage ditch at the top of the pit is U-shaped; Multiple oil-blocking and flow-disrupting devices are installed at equal intervals in the drainage ditch at the top of the pit, and oil-blocking and flow-disrupting devices are also installed in the main outlet pipe drainage channel. The oil-blocking and flow-disrupting devices include an oil-blocking plate installed above and a water-retaining plate installed below. The oil-blocking plate and the water-retaining plate are installed along the water flow direction, and their projections overlap in the vertical direction. The width of the oil separator is the same as the width of the drainage ditch at the top of the pit or the main outlet pipe, and there is a gap between the bottom of the oil separator and the bottom of the drainage ditch at the top of the pit or the main outlet pipe. The width of the water-retaining plate is the same as the width of the drainage ditch on the top of the pit or the main outlet pipe.

[0018] Specifically, oil spill containment devices are installed at 50m intervals within the drainage ditch at the top of the pit and 10-20m downstream of the main outlet pipe. These devices consist of an oil-separating plate and a water-retaining plate. The oil-separating plate is made of 5mm thick steel plate, 60cm wide (matching the ditch width), and 40-70cm high (adjusted according to ditch depth), with its lower end suspended 10-20cm above the ground to allow water to flow underneath. The water-retaining plate is also made of 5mm thick steel plate, 60cm wide (matching the ditch width), and 20-50cm high (adjusted according to ditch depth), with its lower end in contact with the ditch bottom to create a water-retaining effect, facilitating particle sedimentation.

[0019] In one embodiment, the water interception system includes a water interception curtain located underground at the bottom of the foundation pit retaining structure surrounding the deep foundation pit. The water interception curtain includes a diaphragm wall and interlocking piles. The bottom of the diaphragm wall and interlocking piles enters a clay water-tight layer, and the diaphragm wall and interlocking piles together form a basin-shaped groundwater blocking zone.

[0020] Specifically, the diaphragm wall and interlocking piles underground in the foundation pit retaining structure also serve as a water-cutting curtain. The bottom of the diaphragm wall and interlocking piles penetrates into the clay impermeable layer, forming a "basin-shaped groundwater blocking zone" to block the hydraulic connection between the inside and outside of the pit. Specifically, the deep foundation pit site is leveled to the design ground elevation, and then three-axis mixing piles, diaphragm walls, and interlocking piles are constructed. The diaphragm wall is 800mm thick and 31.20–41.20m deep, constructed in a staggered manner with one or more trench sections, using the "three-grab method" for trench formation, and underwater concrete pouring. The interlocking piles use C35P10 underwater concrete for the solid piles and C25P10 underwater ultra-slow-setting concrete for the plain piles. The diaphragm wall and interlocking piles penetrate 3–5m into the clay impermeable layer.

[0021] In one embodiment, a waterproofing system is also included, which consists of retaining walls installed at the top of the pit drainage ditch, multi-stage sedimentation tanks, around the deep foundation pit, inside the main outlet pipe drainage channel, and greening of open spaces.

[0022] Specifically, a waterproof system is formed by the drainage ditch at the top of the pit, the sedimentation basin, the retaining wall around the deep foundation pit, the inner side of the intercepting ditch, and the greening of open areas to prevent surface water and water from outside the pit from overflowing into the pit. The drainage ditch at the top of the pit measures 600mm × 600mm, with a net depth of 60–100cm. The bottom of the drainage ditch has a 3‰ longitudinal slope and is treated with EVA tunnel waterproofing membrane to prevent seepage and seepage into the temporary slope. The retaining wall is a 60cm high, 15cm thick plain concrete structure.

[0023] In one embodiment, the multi-stage sedimentation tank includes a grit chamber, a primary sedimentation tank, a secondary sedimentation tank, a tertiary sedimentation tank, a quaternary sedimentation tank, and a quinary sedimentation tank arranged sequentially. The primary sedimentation tank and the secondary sedimentation tank also serve as biological and biochemical conditioning tanks. Hydrolysis and acid oxidation are carried out through the catalysis of biological bacteria and the addition of catalytic oxidation agents. A spray diffusion device is installed at the front end of the biological and biochemical conditioning tank. The spray diffusion device blows in air and ozone for aeration, denitrification and pre-oxidation. The third-stage sedimentation tank is a hydrolysis acidification tank and equalization tank used for introducing bacterial strains. A catalytic oxidation reaction zone is set up at the partition wall between the third-stage sedimentation tank and the fourth-stage sedimentation tank, where COD removal agent, PAM agent and PAC agent are added; The fourth-stage sedimentation tank is an intermediate water tank where the water and related reagents are fully mixed and the reaction takes place. The fifth-stage sedimentation tank is equipped with a lift pump, which lifts the water to the ozone reaction system.

[0024] Specifically, the grit chamber, primary sedimentation tank, secondary sedimentation tank, tertiary sedimentation tank, quaternary sedimentation tank, and quinary sedimentation tank are all reinforced concrete structures, designed as a single unit, with a total net size of 56m × 20m × 2.1m. The tank bottom is filled with 100cm thick rubble, the bedding layer is made of 10cm thick C20 concrete, and the tank walls are made of 30cm thick C30 P6 impermeable concrete, with several steel bars embedded in the tank walls.

[0025] Biological and biochemical conditioning tank. The primary and secondary sedimentation tanks also serve as biological and biochemical conditioning tanks, where hydrolysis and acid oxidation are carried out through catalytic oxidation by biological microorganisms and the addition of catalytic oxidation agents. The biological microorganisms attach to floating islands of aquatic plants, with the water hyacinth root system providing a habitat for the microorganisms (denitrifying and phosphorus-removing bacteria, heavy metal-tolerant bacteria) to attach and reproduce. The floating islands are made of a composite material of plastic and steel, with petal-shaped packing installed inside; a total of 60 sets of composite materials are arranged, with each individual structure measuring 2m×2m×2m. The structure replaces the pressed plastic discs with double-ringed large plastic rings, with aldehyde-modified fibers or polyester filaments pressed onto the rings to ensure even distribution of fiber bundles; the inner ring consists of snowflake-shaped plastic branches, which can both support biofilm and effectively cut air bubbles, improving the oxygen transfer rate and utilization rate; this allows for sufficient exchange between water, air, and biofilm, thus achieving efficient treatment of organic matter in the water. A spray diffusion device is installed at the front end of the tank to introduce air and ozone for aeration, denitrification, and pre-oxidation.

[0026] The hydrolysis acidification tank also serves as a regulating tank. Located in the third-stage sedimentation tank, it is primarily used for introducing microbial inoculum. Its specific functions are as follows: improving the biodegradability of wastewater. Microorganisms typically only utilize organic matter dissolved in water. During this process, large organic molecules in the water are converted into smaller ones, facilitating subsequent aerobic biological treatment; and removing COD from the wastewater. During the hydrolysis acidification process, some organic matter is degraded by microorganisms, a process that also consumes COD.

[0027] In one embodiment, the ozone reaction system includes four ozone reaction towers arranged in parallel. A fifth-stage sedimentation tank is connected to the inlet at the bottom of the four ozone reaction towers via a booster pump. Each ozone reaction tower is connected to a gas source system at its bottom, and each ozone reaction tower is equipped with an ozone exhaust gas destruction system at its exhaust gas outlet. The gas source system includes at least two sets of ozone preparation units arranged in parallel. Each ozone preparation unit includes a screw air compressor, an air storage tank, a cold dryer, an oxygen generator, and an ozone generator arranged in sequence. The outlet of the ozone generator is connected to the top of each ozone reaction tower.

[0028] Specifically, in the ozone reaction tower, when oxygen molecules pass through the high-voltage discharge zone, they are ionized by the high-potential electric field into oxygen atoms. One oxygen atom combines with one oxygen molecule to form ozone.

[0029] Pre-ozone contact oxidation removes odors, color, iron, manganese, heavy metals, and algae, destabilizes colloidal particles in water, improves flocculation, reduces the amount of coagulant added, and removes precursors of THMs and other carcinogenic, teratogenic, and mutagenic substances, reducing their content in water. It can also oxidize large organic molecules into smaller organic molecules and oxidize inorganic substances such as cyanide, carbides, and nitrates.

[0030] After passing through, ozone is contacted for oxidation. When used in combination with activated carbon, ozone kills bacteria and viruses, oxidizes organic matter (such as pesticides, detergents, phenols, etc.), removes COD, and oxidizes and decomposes chelates (such as EDTA and NTA).

[0031] The generator can be supplied with air, liquid oxygen (LOX), or gaseous oxygen. This project uses gaseous oxygen as the gas source, and oxygen is produced on-site using the PSA oxygen generator method through two PSA oxygen generators.

[0032] In addition, an ozone exhaust gas destruction system is required. Environmental regulations permit ozone emissions with a volume fraction of 0.05 × 10⁻⁶ to 0.1 × 10⁻⁶, and a half-life of 20 minutes at room temperature. Due to the influence of water quality and diffusion devices, it is difficult for 100% of the ozone entering the contact tank to be absorbed, resulting in a certain amount of residual ozone in the exhaust gas, which harms human health and pollutes the surrounding environment. High-temperature heating or catalytic methods can be used to treat the exhaust gas from the contact tank. This project adopts the catalytic method, installing two HCOD-2 exhaust gas destruction systems on the reaction tower, utilizing MnO₂-based packing material to decompose and destroy the ozone exhaust gas.

[0033] In one embodiment, a flocculation sedimentation system is installed at the end of the main outlet pipe. The flocculation sedimentation system includes a flocculant dosing pipe, a flocculant sedimentation agitator, and a flow-around component. The flow-around component consists of multiple flow-around plates arranged alternately in the main outlet pipe. The flow-around component is located 35m-45m downstream of the agitator.

[0034] Specifically, a flocculation sedimentation system is installed at the end of the main outlet pipe leading to the five-stage sedimentation tank, in the 50-10m section of the open channel before entering the sedimentation tank. The system consists of a flocculant dosing pipe, a flocculant sedimentation agitator, and a flow bypass plate. Flocculant is added through the flocculant dosing pipe, and a flocculant sedimentation agitator is installed downstream to ensure thorough mixing of the agent and water. Approximately 40m downstream of the agitator, a 4cm×70cm×45cm steel plate serves as a flow bypass plate, slowing the water flow and extending the agent's reaction time.

[0035] In one embodiment, the online water quality monitoring system includes a COD monitor, an ammonia nitrogen monitor, a total phosphorus monitor, a pH monitor, a flow meter, a water quality sampler, and a K37A environmental data acquisition instrument, all connected to a controller.

[0036] Specifically, the online water quality monitoring system monitors pollutant indicators such as COD (chemical oxygen demand), ammonia nitrogen (NH3-N), total phosphorus (TP), total nitrogen (TN), pH, and flow rate at the water outlet in real time 24 hours a day, providing accurate water quality data.

[0037] The COD (Chemical Oxygen Demand) monitor uses the potassium dichromate method, which employs high-temperature digestion and photometric measurement principles to achieve rapid and accurate determination of chemical oxygen demand in water bodies.

[0038] The ammonia nitrogen monitor uses Nessler's reagent spectrophotometry to determine ammonia nitrogen in water and wastewater.

[0039] The total phosphorus monitor uses the ammonium molybdate spectrophotometric method to achieve rapid determination of total phosphorus in water.

[0040] The total nitrogen monitor uses alkaline potassium persulfate digestion ultraviolet spectrophotometry to determine total nitrogen in surface water, groundwater, industrial wastewater and domestic sewage.

[0041] The pH monitor uses high-precision electrodes to accurately reflect the acidity or alkalinity of water in real time.

[0042] The flow meter uses the ultrasonic measurement principle and features high precision, wide measurement range, and low maintenance.

[0043] The water sampler enables various sampling methods, including timed, quantitative, and mixed sampling, to meet diverse water quality monitoring needs.

[0044] The K37A environmental data acquisition instrument utilizes information technologies such as artificial intelligence, the Internet of Things, big data, and cloud computing to achieve intelligent sensing, intelligent early warning, intelligent processing, and intelligent operation and maintenance of the online pollution source monitoring system. Through multiple built-in communication interfaces, such as Ethernet, 4G (full network compatibility) / NB-IoT, the K37A can transmit monitoring data to the monitoring center in real time, enabling remote monitoring and management.

[0045] Another aspect of the present invention provides a neural conduction-based dewatering process for ultra-large area deep foundation pits, comprising the following steps: S1. Interceptive Dewatering: The underground continuous wall and interlocking piles of the foundation pit retaining structure of the deep foundation pit also serve as water-cutting curtains. The bottom of the underground continuous wall and interlocking piles enters the clay water-resistant layer, forming a "basin-shaped groundwater blocking zone" to block the hydraulic connection between the inside and outside of the deep foundation pit. S2, Nerve conduction drainage: Dewatering wells located ≤50m from the edge of the deep foundation pit pump the extracted groundwater directly into the drainage ditch at the top of the pit; Multiple dewatering wells and several collection tanks located more than 50m from the edge of the deep foundation pit constitute multiple neural conduction dewatering units centered on each collection tank. Each neural conduction dewatering unit includes multiple dewatering wells and a collection tank located in the middle of the multiple dewatering wells. All dewatering wells in the same neural conduction dewatering unit are collected into the corresponding collection tank through branch drainage pipes. Each collection tank is connected to the drainage ditch on the top of the pit through the main drainage pipe. S3. Purification treatment: Physical purification, biological purification and chemical purification are carried out in a five-stage sedimentation tank; Physical purification: Filtration is carried out in the grit chamber; Biological purification: The primary and secondary sedimentation tanks also serve as biological and biochemical conditioning tanks. Hydrolysis and acid oxidation are carried out through the catalysis of biological bacteria and the addition of catalytic oxidation agents. A spray diffusion device is installed at the front end of the biological and biochemical conditioning tank. The spray diffusion device blows in air and ozone for aeration, denitrification and pre-oxidation. The third sedimentation tank is a hydrolysis acidification tank and conditioning tank used for adding bacterial strains. Chemical purification: A catalytic oxidation reaction zone is set up at the partition wall between the third and fourth stage sedimentation tanks, where COD removal agent, PAM agent, and PAC agent are added; the fourth stage sedimentation tank is an intermediate water tank, where the water and related agents are fully mixed and the reaction takes place. The fifth-stage sedimentation tank is equipped with a lift pump, which lifts the water to the ozone reaction system.

[0046] S4. Ozone treatment: In the ozone reaction tower, when oxygen molecules pass through the high-voltage discharge zone, they are ionized by the high-potential electric field and become oxygen atoms. One oxygen atom combines with one oxygen molecule to form ozone. In the secondary sedimentation tank, pre-ozone contact oxidation removes odor, color, iron, manganese, heavy metals, and algae, destabilizes colloidal particles in the water, improves flocculation, reduces the amount of coagulant added, removes the precursors of carcinogenic, teratogenic, and mutagenic substances, reduces the content of carcinogenic, teratogenic, and mutagenic substances in the water, oxidizes large organic molecules into small organic molecules, and oxidizes inorganic substances. After ozone contact oxidation is achieved in the ozone reaction tower: ozone is used in combination with activated carbon to kill bacteria and viruses, oxidize organic matter, remove COD, and oxidize and decompose chelates. The S5 online water quality monitoring system monitors pollutant indicators such as COD, ammonia nitrogen, total phosphorus, total nitrogen, pH, and flow rate at the water outlet in real time 24 hours a day, providing accurate water quality data. After treatment, the treated wastewater meets the standards. A water pump is installed in the buffer tank, and water is supplied to the wetland water inlet through the drainage pipe. A buffer screen is installed at the wetland water inlet to prevent water erosion around the water inlet.

[0047] The beneficial effects of this invention are as follows: 1. The neural conduction drainage method significantly reduces the number of high-lift pumps and external drainage pipelines required. Traditional drainage methods would require 30 large dust-generating pumps, while the neural conduction drainage method only requires 17. Precise control through online monitoring and detection systems results in substantial savings in electricity consumption.

[0048] 2. The use of nerve conduction drainage can reduce the daily water in the foundation pit to 5,000 m³ and the daily excavation volume to 20,000 m³, minimizing the mutual interference between water infiltration and earthwork excavation.

[0049] 3. By making full use of the online water level and water quality monitoring system, the reliance on manual labor is greatly reduced, and the water level in the foundation pit and the quality of the external drainage water are accurately and reliably controlled.

[0050] 4. Make full use of conventional structures such as drainage ditches and sedimentation tanks, and install devices in appropriate locations to assist in water purification, such as oil spill isolation devices, baffles, and flocculation sedimentation devices. This will purify the water at the front end, enriching the water purification function of conventional structures and improving the back end.

[0051] 5. A diaphragm wall (interlocking pile) was used to extend into the waterproof layer and also serve as a water-stop curtain. According to relevant drainage parameters, the drainage volume of the soil in the foundation pit was calculated to be 645,000 m³. The actual drainage volume in the foundation pit was 454,000 m³. This achieved the purpose of dewatering by extracting a small amount of groundwater within the excavation area.

[0052] 6. By using this system to reduce drainage, a total of RMB 3.1782 million was saved compared with traditional processes.

[0053] 7. After treatment, the groundwater is discharged into surrounding water bodies, effectively mitigating and replenishing surface water loss that may be caused by foundation pit dewatering, promoting the natural circulation of surrounding water bodies, and protecting and maintaining the balance of the original natural ecosystem. Reusing the treated effluent reduces dependence on tap water and natural water bodies, lowers construction costs, and protects the ecosystem. By cutting off the groundwater supply and recycling the treated groundwater, the amount of foundation pit dewatering and water treatment work can be significantly reduced, lowering energy consumption, reducing carbon emissions, and benefiting environmental protection. Attached Figure Description

[0054] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0055] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the structure of the nerve conduction type drainage collection component and the pit top drainage ditch; Figure 3 This is a schematic diagram of a multi-stage sedimentation tank. Figure 4 This is a schematic diagram of the gas supply system. Figure 5 This is a schematic diagram of the oil-water separation and turbulence control device; Figure 6 This is a schematic diagram of the ozone reaction system; Attached reference numerals: 1. Nerve conduction type drainage collection component; 2. Pit top drainage ditch; 3. Main outlet pipe drainage channel; 4. Multi-stage sedimentation tank; 5. Ozone reaction system; 6. Flow channel; 7. Buffer tank; 8. Storage tank; 9. Wetland water replenishment system; 10. Gas source system; 11. Oil separator and turbulence device; 1.1 Main drainage pipe; 1.2 Branch drainage pipe; 1.3 Water collection tank; 1.4 Dewatering well; 4.1 Grit chamber; 4.2 Primary sedimentation tank; 4.3 Secondary sedimentation tank; 4.4 Tertiary sedimentation tank; 4.5 Quaternary sedimentation tank; 4.6 Fifth sedimentation tank; 5.1 Ozone reaction tower; 10.1 Screw air compressor; 10.2 Air receiver; 10.3 Cold dryer; 10.4 Oxygen generator; 10.5 Ozone generator; 11.1 Oil separator; 11.2 Lower water trap. Detailed Implementation

[0056] To make the technical problems, technical solutions, and technical effects of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0057] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0058] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0059] In the description of the embodiments of the present invention, it should be noted that the terms "inner", "outer", "upper", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0060] Example 1 like Figures 1 to 6 As shown, this embodiment provides one aspect of the present invention: a neural conduction-type dewatering system for ultra-large area deep foundation pits, including a water interception system set outside the deep foundation pit, a pit top drainage ditch 2 set outside the water interception system, a plurality of dewatering wells 1.4 evenly arranged in the deep foundation pit, a neural conduction-type dewatering collection component 1 connected to the plurality of dewatering wells 1.4 and the pit top drainage ditch 2 respectively, a main outlet pipe 3 connected to the pit top drainage ditch 2, a multi-stage sedimentation tank 4 connected to the main outlet pipe 3, an ozone reaction system 5 connected to the multi-stage sedimentation tank 4, a flow channel 6 connected to the ozone reaction system 5, a buffer tank 7 connected to the flow channel 6, and an online water quality and water level monitoring system set in the flow channel 6; The multi-stage sedimentation tank 4 is used in conjunction with physical purification equipment, biological purification devices, and chemical purification equipment, respectively. The outlet of the buffer pool 7 is divided into two pipelines. One pipeline is connected to the storage tank 8, and the other pipeline is connected to the wetland water replenishment system 9 through the water replenishment pipeline.

[0061] Specifically, this plan uses "interception-type precipitation" and "nerve conduction-type drainage" as measures, and organically combines "interception, prevention, reduction, and drainage" measures for treating groundwater inflow through "physical purification + biological purification + chemical purification". It is supplemented by information technology means such as automated water level monitoring and water quality monitoring to achieve the effect of dewatering during foundation pit excavation. At the same time, by comprehensively utilizing the tailwater and replenishing the surrounding wetlands, it improves the sustainable use of non-traditional water sources and reduces groundwater waste and impact on the surrounding environment.

[0062] Two 60m³ water storage tanks (8) are installed on site, with a total storage capacity of 120m³, which can meet the water needs for construction and production such as spraying, dust suppression, greening spraying, and concrete curing. The treated wastewater that meets the standards is pumped by a 7.5KW water pump in buffer pool (7) and supplied to the wetland water inlet via the D160 drainage pipe. A buffer screen is installed at the wetland water inlet to prevent water erosion around the inlet.

[0063] Example 2 This embodiment is a further optimization based on Embodiment 1, specifically: The nerve conduction type drainage collection component 1 includes several evenly distributed rainwater wells 1.4 and several evenly distributed water collection tanks 1.3; Dewatering wells 1.4, located ≤50m from the edge of the deep foundation pit, pump out groundwater directly into drainage ditch 2 at the top of the pit; The dewatering wells 1.4 located more than 50m from the edge of the deep foundation pit and several water collection tanks 1.3 constitute multiple neural conduction dewatering units centered on each water collection tank 1.3; each neural conduction dewatering unit includes multiple dewatering wells 1.4 and water collection tanks 1.3 located in the middle of multiple dewatering wells 1.4. All dewatering wells 1.4 of the same neural conduction dewatering unit are collected into the corresponding water collection tank 1.3 through branch drainage pipes 1.2. Each water collection tank 1.3 is connected to the pit top drainage ditch 2 through the main drainage pipe 1.1. Several dewatering wells 1.4 are arranged in an equilateral triangle at a set interval. The distance from all dewatering wells 1.4 to the corresponding water collection tank 1.3 within the same nerve conduction type dewatering unit is less than 50m.

[0064] Specifically, the dewatering well 1.4 within the pit was constructed according to the following process: "Construction preparation → Drilling of dewatering well 1.4 → Final drilling → Lowering of well casing → Backfilling with medium-coarse sand → Mud sealing → Well washing and pumping". The wells used 700mm diameter, 273mm diameter bridge-type filter pipes, with a depth of 25-35m, arranged in an equilateral triangle pattern at 20m intervals, and constructed from the ground. Before officially commencing dewatering, the elevation of each wellhead and the ground surface were measured, the stable water level was determined, and pumping equipment, water level monitoring equipment, cables, and drainage channels were arranged to ensure the normal operation of the entire dewatering system.

[0065] Groundwater extracted from the central area of ​​the foundation pit (more than 50m from the edge) is collected in a nearby water collection tank 1.3. Tank 1.3 measures 2.4m × 1.6m × 1.5m (length × width × height) and has a maximum storage capacity of 5.76m³. The water is then centrally pumped to the drainage ditch 2 at the top of the pit, preventing infiltration and ensuring effective dewatering. This also reduces the number of exit pipes, minimizing the impact on earthwork excavation. Groundwater extracted from the surrounding area of ​​the deep foundation pit (≤50m from the edge) is directly pumped to the drainage ditch 2 at the top of the pit.

[0066] After the foundation pits were excavated to the design elevation of the base at the junctions of the pits within the pits, the boundaries of each storage block, and the elevation range of the impermeable layer, a neural network filter system with first to third-stage blind pipes was installed at the junctions to fully collect scattered water and rainwater within the pits. The blind pipes were made of HDPE rigid permeable pipes, and the trenches were trapezoidal, backfilled with medium to coarse sand. The first-stage blind pipes had a diameter of 300mm and a trench size of 600mm×600mm; the second-stage blind pipes had a diameter of 150mm and a trench size of 300mm×300mm; and the third-stage blind trench had no blind pipes and a trench size of 300mm×300mm.

[0067] Example 3 This embodiment is a further optimization based on Embodiment 1, specifically: The cross-section of the drainage ditch 2 at the top of the pit is U-shaped; Multiple oil-blocking and flow-disrupting devices 11 are installed at equal intervals in the drainage ditch 2 at the top of the pit, and oil-blocking and flow-disrupting devices 11 are also installed in the main water outlet pipe ditch 3. Each oil-blocking and flow-disrupting device 11 includes an oil-blocking plate 11.1 installed at the top and a water-retaining plate 11.2 installed at the bottom. The oil-blocking plate 11.1 and the water-retaining plate are installed along the water flow direction, and their projections overlap in the vertical direction. The width of the oil separator 11.1 is the same as the width of the pit top drainage ditch 2 or the main outlet pipe drainage channel 3, and there is a gap between the bottom of the oil separator 11.1 and the bottom of the pit top drainage ditch 2 or the main outlet pipe drainage channel 3. The width of the water-retaining plate is the same as the width of the top drainage ditch 2 or the main outlet pipe ditch 3.

[0068] Specifically, oil spill containment devices are installed at 50m intervals within the drainage ditch 2 at the top of the pit, and 10-20m downstream of the main outlet pipe. Each oil spill containment device consists of an oil separator 11.1 and a water trap. The oil separator 11.1 is made of 5mm thick steel plate, 60cm wide (matching the ditch width), and 40-70cm high (adjusted according to ditch depth), with its lower end suspended 10-20cm above the ground to allow water to flow underneath. The water trap is also made of 5mm thick steel plate, 60cm wide (matching the ditch width), and 20-50cm high (adjusted according to ditch depth), with its lower end in contact with the ditch bottom to create a water trap effect, facilitating particle sedimentation.

[0069] Example 4 This embodiment is a further optimization based on embodiment 3, specifically: The water interception system includes a water-cutting curtain located underground at the bottom of the foundation pit retaining structure surrounding the deep foundation pit. The water-cutting curtain includes a diaphragm wall and interlocking piles. The bottom of the diaphragm wall and interlocking piles enters the clay water-tight layer, and the diaphragm wall and interlocking piles together form a basin-shaped groundwater blocking zone.

[0070] Specifically, the diaphragm wall and interlocking piles underground in the foundation pit retaining structure also serve as a water-cutting curtain. The bottom of the diaphragm wall and interlocking piles penetrates into the clay impermeable layer, forming a "basin-shaped groundwater blocking zone" to block the hydraulic connection between the inside and outside of the pit. Specifically, the deep foundation pit site is leveled to the design ground elevation, and then three-axis mixing piles, diaphragm walls, and interlocking piles are constructed. The diaphragm wall is 800mm thick and 31.20–41.20m deep, constructed in a staggered manner with one or more trench sections, using the "three-grab method" for trench formation, and underwater concrete pouring. The interlocking piles use C35P10 underwater concrete for the solid piles and C25P10 underwater ultra-slow-setting concrete for the plain piles. The diaphragm wall and interlocking piles penetrate 3–5m into the clay impermeable layer.

[0071] Example 5 This embodiment is a further optimization based on embodiment 4, specifically: It also includes a waterproofing system, which consists of retaining walls installed on the top drainage ditch 2, multi-stage sedimentation tank 4, the perimeter of the deep foundation pit, the inner side of the main outlet drainage ditch 3, and greening of open spaces.

[0072] Specifically, a waterproof system is formed by the top drainage ditch 2, sedimentation tank 4.1, the retaining wall around the deep foundation pit, the inner side of the intercepting ditch, and the greening of open areas to prevent surface water and water from outside the pit from overflowing into the pit. The top drainage ditch 2 measures 600mm × 600mm, with a net depth of 60–100cm. The bottom of the top drainage ditch 2 has a 3‰ longitudinal slope and is treated with EVA tunnel waterproofing membrane to prevent seepage and seepage into the temporary slope. The retaining wall is a 60cm high, 15cm thick plain concrete structure.

[0073] Example 6 This embodiment is a further optimization based on embodiment 5, specifically: The multi-stage sedimentation tank 4 includes a grit chamber 4.1, a primary sedimentation tank 4.2, a secondary sedimentation tank 4.3, a tertiary sedimentation tank 4.4, a quaternary sedimentation tank 4.5, and a quinary sedimentation tank 4.6 arranged sequentially. The primary sedimentation tank 4.2 and the secondary sedimentation tank 4.3 also serve as biological and biochemical conditioning tanks. Hydrolysis and acid oxidation are carried out through the catalysis of biological bacteria and the addition of catalytic oxidation agents. A spray diffusion device is installed at the front end of the biological and biochemical conditioning tank. The spray diffusion device blows in air and ozone for aeration, denitrification and pre-oxidation. The third-stage sedimentation tank 4.4 is a hydrolysis acidification tank and equalization tank used for introducing bacterial strains; A catalytic oxidation reaction zone is set at the partition wall of the third-stage sedimentation tank 4.4 and the fourth-stage sedimentation tank 4.5, where COD removal agent, PAM agent and PAC agent are added; The fourth-stage sedimentation tank 4.5 is an intermediate water tank where the water and related reagents are fully mixed and the reaction occurs. A booster pump is installed in the fifth-stage sedimentation tank 4.6 to lift the water to the ozone reaction system 5.

[0074] Specifically, sedimentation tanks 4.1, 4.2, 4.3, 4.4, 4.5, and 4.6 are all reinforced concrete structures, designed as a single unit, with a total net size of 56m × 20m × 2.1m. The tank bottom is filled with 100cm thick rubble, the subbase is made of 10cm thick C20 concrete, and the tank walls are made of 30cm thick C30 P6 impermeable concrete, with several steel bars embedded within the tank walls.

[0075] Biological and biochemical conditioning tank. The primary and secondary sedimentation tanks (4.3) also serve as biological and biochemical conditioning tanks, using biological microorganisms for catalytic oxidation and the addition of catalytic oxidation agents for hydrolysis and acid oxidation. The biological microorganisms attach to floating islands of aquatic plants, with water hyacinth roots providing a habitat for the microorganisms (denitrifying and phosphorus-removing bacteria, heavy metal-tolerant bacteria) to attach and reproduce. The floating islands are constructed of a composite material of plastic and steel, with internal petal-shaped packing; a total of 60 sets of composite materials are arranged, with individual structures measuring 2m × 2m × 2m. The structure replaces the pressed plastic discs with double-ringed large plastic rings, pressing aldehyde-modified fibers or polyester filaments onto the rings to ensure even fiber distribution. The inner ring consists of snowflake-shaped plastic branches, which can both support biofilm and effectively cut air bubbles, improving oxygen transfer rate and utilization. This allows for sufficient exchange between water, air, and the biofilm, resulting in efficient treatment of organic matter in the water. A spray diffusion device is installed at the front end of the tank to introduce air and ozone for aeration, denitrification, and pre-oxidation.

[0076] The hydrolysis acidification tank also serves as a regulating tank. Located in the third-stage sedimentation tank (4.4), it is primarily used for introducing microbial inoculum. Its specific functions are as follows: improving the biodegradability of wastewater. Microorganisms typically only utilize organic matter dissolved in water. During this process, large organic molecules in the water are converted into smaller organic molecules, facilitating subsequent aerobic biological treatment; and removing COD from the wastewater. During the hydrolysis acidification process, some organic matter is degraded by microorganisms, a process that also consumes COD.

[0077] Example 7 This embodiment is a further optimization based on embodiment 6, specifically: The ozone reaction system 5 includes four ozone reaction towers 5.1 arranged in parallel. The fifth-stage sedimentation tank 4.6 is connected to the water inlet at the bottom of the four ozone reaction towers 5.1 through a booster pump. Each ozone reaction tower 5.1 is connected to a gas source system 10 at the bottom. Each ozone reaction tower 5.1 is equipped with an ozone tail gas destruction system at the tail gas outlet at the top. The gas source system 10 includes at least two sets of ozone preparation units arranged in parallel. Each ozone preparation unit includes a screw air compressor 10.1, an air storage tank 10.2, a cold dryer 10.3, an oxygen generator 10.4, and an ozone generator 10.5 arranged in sequence. The outlet of the ozone generator 10.5 is connected to the top of each ozone reaction tower 5.1.

[0078] Specifically, in ozone reaction tower 5.1, when oxygen molecules pass through the high-voltage discharge zone, they are ionized by the high-potential electric field into oxygen atoms. One oxygen atom combines with one oxygen molecule to form ozone.

[0079] Pre-ozone contact oxidation removes odors, color, iron, manganese, heavy metals, and algae, destabilizes colloidal particles in water, improves flocculation, reduces the amount of coagulant added, and removes precursors of THMs and other carcinogenic, teratogenic, and mutagenic substances, reducing their content in water. It can also oxidize large organic molecules into smaller organic molecules and oxidize inorganic substances such as cyanide, carbides, and nitrates.

[0080] After passing through, ozone is contacted for oxidation. When used in combination with activated carbon, ozone kills bacteria and viruses, oxidizes organic matter (such as pesticides, detergents, phenols, etc.), removes COD, and oxidizes and decomposes chelates (such as EDTA and NTA).

[0081] The generator's gas source can be air, liquid oxygen (LOX), or gaseous oxygen. This project uses gaseous oxygen as the gas source, and oxygen is produced on-site using the PSA oxygen generation method through two PSA oxygen generators.

[0082] In addition, an ozone exhaust gas destruction system is required. Environmental regulations permit ozone emissions with a volume fraction of 0.05 × 10⁻⁶ to 0.1 × 10⁻⁶, and a half-life of 20 minutes at room temperature. Due to the influence of water quality and diffusion devices, it is difficult for 100% of the ozone entering the contact tank to be absorbed, resulting in a certain amount of residual ozone in the exhaust gas, which harms human health and pollutes the surrounding environment. High-temperature heating or catalytic methods can be used to treat the exhaust gas from the contact tank. This project adopts the catalytic method, installing two HCOD-2 exhaust gas destruction systems on the reaction tower, utilizing MnO₂-based packing material to decompose and destroy the ozone exhaust gas.

[0083] Example 8 This embodiment is a further optimization based on embodiment 7, specifically: A flocculation and sedimentation system is installed at the end of the main outlet pipe 3. The flocculation and sedimentation system includes a flocculant dosing pipe, a flocculant sedimentation agitator, and a flow-around component. The flow-around component consists of multiple flow-around plates arranged alternately in the main outlet pipe 3. The flow-around component is located 35m-45m downstream of the agitator.

[0084] Specifically, a flocculation sedimentation system is installed at the end of the main outlet pipe 3 of the fifth-stage sedimentation tank (4.6), in the 50-10m section of the open channel before entering the sedimentation tank. The system consists of a flocculant dosing pipe, a flocculant sedimentation agitator, and a flow bypass plate. Flocculant is added through the flocculant dosing pipe, and a flocculant sedimentation agitator is installed downstream to ensure thorough mixing of the agent and water. Approximately 40m downstream of the agitator, a 4cm×70cm×45cm steel plate is used as a flow bypass plate to slow the water flow and extend the agent's reaction time.

[0085] Example 9 This embodiment is a further optimization based on embodiment 8, specifically: The online water quality monitoring system includes a COD monitor, an ammonia nitrogen monitor, a total phosphorus monitor, a pH monitor, a flow meter, a water quality sampler, and a K37A environmental data acquisition instrument, all connected to the controller.

[0086] Specifically, the online water quality monitoring system monitors pollutant indicators such as COD (chemical oxygen demand), ammonia nitrogen (NH3-N), total phosphorus (TP), total nitrogen (TN), pH, and flow rate at the water outlet in real time 24 hours a day, providing accurate water quality data.

[0087] The COD (Chemical Oxygen Demand) monitor uses the potassium dichromate method, which employs high-temperature digestion and photometric measurement principles to achieve rapid and accurate determination of chemical oxygen demand in water bodies.

[0088] The ammonia nitrogen monitor uses Nessler's reagent spectrophotometry to determine ammonia nitrogen in water and wastewater.

[0089] The total phosphorus monitor uses the ammonium molybdate spectrophotometric method to achieve rapid determination of total phosphorus in water.

[0090] The total nitrogen monitor uses alkaline potassium persulfate digestion ultraviolet spectrophotometry to determine total nitrogen in surface water, groundwater, industrial wastewater and domestic sewage.

[0091] The pH monitor uses high-precision electrodes to accurately reflect the acidity or alkalinity of water in real time.

[0092] The flow meter uses the ultrasonic measurement principle and features high precision, wide measurement range, and low maintenance.

[0093] The water sampler enables various sampling methods, including timed, quantitative, and mixed sampling, to meet diverse water quality monitoring needs.

[0094] The K37A environmental data acquisition instrument utilizes information technologies such as artificial intelligence, the Internet of Things, big data, and cloud computing to achieve intelligent sensing, intelligent early warning, intelligent processing, and intelligent operation and maintenance of the online pollution source monitoring system. Through multiple built-in communication interfaces, such as Ethernet, 4G (full network compatibility) / NB-IoT, the K37A can transmit monitoring data to the monitoring center in real time, enabling remote monitoring and management.

[0095] Example 10 This embodiment provides a neural conduction-based dewatering process for ultra-large area deep foundation pits, including the following steps: S1. Interceptive Dewatering: The underground continuous wall and interlocking piles of the foundation pit retaining structure of the deep foundation pit also serve as water-cutting curtains. The bottom of the underground continuous wall and interlocking piles enters the clay water-resistant layer, forming a "basin-shaped groundwater blocking zone" to block the hydraulic connection between the inside and outside of the deep foundation pit. S2, Neural Conduction Drainage: Dewatering wells 1.4 located ≤50m from the edge of the deep foundation pit pump the extracted groundwater directly into the drainage ditch 2 at the top of the pit; The dewatering wells 1.4 located more than 50m from the edge of the deep foundation pit and several water collection tanks 1.3 constitute multiple neural conduction dewatering units centered on each water collection tank 1.3; each neural conduction dewatering unit includes multiple dewatering wells 1.4 and water collection tanks 1.3 located in the middle of multiple dewatering wells 1.4. All dewatering wells 1.4 of the same neural conduction dewatering unit are collected into the corresponding water collection tank 1.3 through branch drainage pipes 1.2. Each water collection tank 1.3 is connected to the pit top drainage ditch 2 through the main drainage pipe 1.1. S3. Purification treatment: Physical purification, biological purification and chemical purification are carried out in the five-stage sedimentation tank 4.6; Physical purification: Filtration is carried out in the grit chamber 4.1; Biological purification: The primary sedimentation tank 4.2 and the secondary sedimentation tank 4.3 also serve as biological and biochemical conditioning tanks. Hydrolysis and acid oxidation are carried out through the catalysis of biological bacteria and the addition of catalytic oxidation agents. A spray diffusion device is installed at the front end of the biological and biochemical conditioning tank. The spray diffusion device blows in air and ozone for aeration, denitrification and pre-oxidation. The third sedimentation tank 4.4 is a hydrolysis acidification tank and conditioning tank used for the introduction of bacterial strains. Chemical purification: A catalytic oxidation reaction zone is set at the partition wall of the third-stage sedimentation tank 4.4 and the fourth-stage sedimentation tank 4.5, where COD removal agent, PAM agent and PAC agent are added; the fourth-stage sedimentation tank 4.5 is an intermediate water tank, where the water and related agents are fully mixed and the reaction takes place. A booster pump is installed in the fifth-stage sedimentation tank 4.6 to lift the water to the ozone reaction system 5.

[0096] S4. Ozone treatment: In ozone reaction tower 5.1, when oxygen molecules pass through the high-voltage discharge zone, they are ionized by the high-potential electric field and become oxygen atoms. One oxygen atom combines with one oxygen molecule to form ozone. In the secondary sedimentation tank 4.3, pre-ozone contact oxidation is used to remove odor, color, iron, manganese, heavy metals and algae, destabilize colloidal particles in the water, improve flocculation effect, reduce the amount of coagulant added, remove the precursors of carcinogenic, teratogenic and mutagenic substances, reduce the content of carcinogenic, teratogenic and mutagenic substances in the water, oxidize large molecular organic matter into small molecular organic matter, and oxidize inorganic substances. After ozone contact oxidation is achieved in ozone reaction tower 5.1: ozone is used in combination with activated carbon to kill bacteria and viruses, oxidize organic matter, remove COD, and oxidize and decompose chelates. The S5 online water quality monitoring system monitors pollutant indicators such as COD, ammonia nitrogen, total phosphorus, total nitrogen, pH, and flow rate at the water outlet in real time 24 hours a day, providing accurate water quality data. After treatment, the treated wastewater meets the standards. A water pump is installed in buffer tank 7 to replenish the water to the wetland water inlet through the drainage pipe. A buffer screen is installed at the wetland water inlet to prevent water erosion around the water inlet.

Claims

1. A nerve conduction type dewatering system for a super-large area deep foundation pit, characterized in that, The system comprises a cutoff system arranged at the periphery of a deep foundation pit, a pit top drainage ditch (2) arranged at the periphery of the cutoff system, a plurality of dewatering wells (1.4) arranged uniformly in the deep foundation pit, a nerve conduction type dewatering and drainage collection assembly (1) respectively communicated with the plurality of dewatering wells (1.4) and the pit top drainage ditch (2), a total water outlet pipe drainage channel (3) communicated with the pit top drainage ditch (2), a multi-stage sedimentation tank (4) communicated with the total water outlet pipe drainage channel (3), an ozone reaction system (5) communicated with the multi-stage sedimentation tank (4), a flow channel (6) communicated with the ozone reaction system (5), a buffer tank (7) communicated with the flow channel (6), and a water quality and water level online monitoring system arranged in the flow channel (6). The multi-stage sedimentation tank (4) is matched with physical purification equipment, biological purification equipment and chemical purification equipment. The buffer tank (7) is divided into two pipelines at the outlet, one pipeline is communicated with a water storage tank (8), and the other pipeline is communicated with a wetland water supplement system (9) through a water supplement pipeline.

2. The nerve conducting dewatering system for very large area deep foundation pit according to claim 1, characterized in that, The nerve conduction type dewatering and drainage collection assembly (1) comprises a plurality of uniformly distributed dewatering wells (1.4) and a plurality of uniformly distributed water collecting tanks (1.3). The dewatering well (1.4) with a distance of less than or equal to 50 m from the edge of the deep foundation pit directly drains the underground water into the pit top drainage ditch (2). The dewatering well (1.4) with a distance of more than 50 m from the edge of the deep foundation pit and the plurality of water collecting tanks (1.3) form a plurality of nerve conduction type dewatering and drainage units with each water collecting tank (1.3) as the center; each nerve conduction type dewatering and drainage unit comprises a plurality of dewatering wells (1.4) and a water collecting tank (1.3) arranged at the middle of the plurality of dewatering wells (1.4), all the dewatering wells (1.4) of the same nerve conduction type dewatering and drainage unit are collected into the corresponding water collecting tank (1.3) through a branch drainage pipe (1.2), and each water collecting tank (1.3) is communicated with the pit top drainage ditch (2) through a main drainage pipe (1.1). The plurality of dewatering wells (1.4) are arranged in an equilateral triangle shape with a set interval, and the distance from all the dewatering wells (1.4) in the same nerve conduction type dewatering and drainage unit to the corresponding water collecting tank (1.3) is less than 50 m.

3. The deep excavation nerve drain system of claim 2, wherein, The cross section of the pit top drainage ditch (2) is U-shaped. A plurality of oil separation and flow disturbance devices (11) are arranged at equal intervals in the pit top drainage ditch (2), and the oil separation and flow disturbance devices (11) are also arranged in the total water outlet pipe drainage channel (3), the oil separation and flow disturbance device (11) comprises an oil separation plate (11.1) arranged above and a water collecting plate arranged below, the oil separation plate (11.1) and the water collecting plate are arranged along the water flow direction, and the projections of the oil separation plate (11.1) and the water collecting plate in the vertical direction are partially overlapped. The width of the oil separation plate (11.1) is the same as the width of the pit top drainage ditch (2) or the total water outlet pipe drainage channel (3), and there is a gap between the bottom of the oil separation plate (11.1) and the bottom of the pit top drainage ditch (2) or the total water outlet pipe drainage channel (3). The width of the water collecting plate is the same as the width of the pit top drainage ditch (2) or the total water outlet pipe drainage channel (3).

4. The nerve conducting dewatering system for very large area deep excavation according to claim 1, characterized in that, The water interception system comprises a water interception curtain arranged underground at the bottom of the foundation enclosure of the deep foundation pit, the water interception curtain comprising a diaphragm wall and a secant pile, the diaphragm wall and the secant pile entering a clay water-resisting layer at the bottom, and the diaphragm wall and the secant pile forming a basin-shaped underground water blocking area as a whole.

5. The ultra-large area deep foundation pit nerve conduction type dewatering system according to claim 1, characterized in that, The waterproof system comprises a water retaining wall arranged inside the top drainage ditch (2), the multi-stage sedimentation tank (4), the periphery of the deep foundation pit, the total water outlet pipe drainage ditch (3) and the green space.

6. The nerve conducting dewatering system for very large area deep excavation according to claim 1, characterized in that, The multi-stage sedimentation tank (4) comprises a sand settling tank (4.1), a first-stage sedimentation tank (4.2), a second-stage sedimentation tank (4.3), a third-stage sedimentation tank (4.4), a fourth-stage sedimentation tank (4.5) and a fifth-stage sedimentation tank (4.6) arranged in sequence. The first-stage sedimentation tank (4.2) and the second-stage sedimentation tank (4.3) are used as biological biochemical adjustment tanks, water hydrolysis acid oxidation is performed through biological bacteria catalysis and by adding catalytic oxidation reagents, a spraying diffusion device is arranged at the front end of the biological biochemical adjustment tank, air and ozone are introduced into the spraying diffusion device for aeration denitrification and pre-oxidation. The third-stage sedimentation tank (4.4) is a hydrolysis acidification tank used for adding bacteria and used as an adjustment tank. A catalytic oxidation reaction zone is arranged at the partition wall between the third-stage sedimentation tank (4.4) and the fourth-stage sedimentation tank (4.5), and the catalytic oxidation reaction zone is used for adding COD removing agent, PAM reagent and PAC reagent. The fourth-stage sedimentation tank (4.5) is an intermediate tank, and water and related reagents are fully mixed in the intermediate tank to react. A lifting pump is arranged in the fifth-stage sedimentation tank (4.6), and the lifting pump is used to lift water to an ozone reaction system (5).

7. The deep excavation nerve drain system of claim 6, wherein, The ozone reaction system (5) comprises four ozone reaction towers (5.1) arranged side by side, the fifth-stage sedimentation tank (4.6) is communicated with water inlets at the bottom of the four ozone reaction towers (5.1) through a lifting pump, an air source system (10) is connected to the bottom of each ozone reaction tower (5.1), and an ozone tail gas destruction system is arranged at tail gas outlets at the top of each ozone reaction tower (5.1). The air source system (10) comprises at least two groups of ozone preparation units arranged side by side, each ozone preparation unit comprises a screw air compressor (10.1), a gas storage tank (10.2), a cold dryer (10.3), an oxygen generator (10.4) and an ozone generator (10.5) arranged in sequence, and the outlet of the ozone generator (10.5) is communicated with the top of each ozone reaction tower (5.1).

8. The nerve conducting dewatering system for very large area deep excavation according to claim 1, characterized in that, A flocculation and sedimentation system is arranged at the end of the total water outlet pipe drainage ditch (3), the flocculation and sedimentation system comprises a flocculant adding pipe, a flocculant sedimentation stirrer and a flow around assembly, the flow around assembly comprises a plurality of flow around plates arranged in the total water outlet pipe drainage ditch (3) in a staggered manner, and the flow around assembly is located at 35 m-45 m downstream of the stirrer.

9. The deep excavation nerve conductive dewatering system of claim 6, wherein, The water quality online monitoring system comprises a COD monitor, an ammonia nitrogen monitor, a total phosphorus monitor, a pH monitor, a flowmeter, a water quality sampler and a K37A environmental protection data acquisition instrument connected with a controller.

10. The nerve conduction type dewatering process for super-large area deep foundation pit, using any one of claims 1 to 9, characterized in that, The method comprises the following steps: S1, Block precipitation: The underground continuous wall and the interlocking pile of the deep foundation pit support structure of the deep foundation pit serve as a cutoff curtain. The underground continuous wall and the interlocking pile enter the clay aquiclude at the bottom, and form a "basin type underground water blocking area" as a whole, thereby blocking the hydraulic connection between the inside and outside of the deep foundation pit; S2, Nerve conduction type drainage: The water pumped out of the precipitation well (1.4) located within a distance of 50 m from the edge of the deep foundation pit is directly drained into the top drainage ditch (2) of the deep foundation pit; The precipitation well (1.4) located within a distance of more than 50 m from the edge of the deep foundation pit and the water collecting tank (1.3) constitute a plurality of nerve conduction type drainage units with the water collecting tank (1.3) as the center; each nerve conduction type drainage unit includes a plurality of precipitation wells (1.4) and a water collecting tank (1.3) arranged in the middle of the plurality of precipitation wells (1.4). All the precipitation wells (1.4) of the same nerve conduction type drainage unit are collected into the corresponding water collecting tank (1.3) through the branch drainage pipe (1.2), and each water collecting tank (1.3) is connected with the top drainage ditch (2) of the deep foundation pit through the main drainage pipe (1.1); S3, Purification treatment: Physical purification, biological purification and chemical purification are carried out in the five-stage sedimentation tank (4.6); Physical purification: Filtration treatment is carried out in the sand settling tank (4.1); Biological purification: The first-stage sedimentation tank (4.2) and the second-stage sedimentation tank (4.3) serve as biological biochemical conditioning tanks. Through the catalysis of biological bacteria groups and the addition of catalytic oxidation reagents, hydrolytic acidification and acid-oxidation are carried out. A spraying diffusion device is arranged at the front end of the biological biochemical conditioning tank. Air and ozone are blown into the spraying diffusion device for aeration denitrification and pre-oxidation. The third-stage sedimentation tank (4.4) is a hydrolytic acidification tank for adding bacteria and a conditioning tank; Chemical purification: The catalytic oxidation reaction zone is arranged at the partition wall of the third-stage sedimentation tank (4.4) and the fourth-stage sedimentation tank (4.5). COD removal agent, PAM reagent and PAC reagent are added in the catalytic oxidation reaction zone. The fourth-stage sedimentation tank (4.5) is an intermediate tank. After the water body and related reagents in the intermediate tank are fully mixed, a reaction occurs; The fifth-stage sedimentation tank (4.6) is provided with a lifting pump. The water body is lifted to the ozone reaction system (5) through the lifting pump; S4, Ozone treatment: In the ozone reaction tower (5.1), oxygen molecules are ionized into oxygen atoms when passing through the high-voltage discharge area. One oxygen atom combines with one oxygen molecule to form ozone. In the second-stage sedimentation tank (4.3), pre-ozone contact oxidation is carried out to remove odor, color, iron, manganese, heavy metals and algae, make the colloidal particles in the water unstable, improve the flocculation effect, reduce the dosage of coagulant, remove the parent substances of three carcinogenic substances, reduce the content of three carcinogenic substances in the water, oxidize large molecular organic matter into small molecular organic matter, and oxidize inorganic matter; In the ozone reaction tower (5.1), post-ozone contact oxidation is realized. Ozone is used in combination with activated carbon to kill bacteria and viruses, oxidize organic matter, remove COD and oxidize and decompose chelates; S5, The water quality online monitoring system monitors the pollutant indicators COD, ammonia nitrogen, total phosphorus, total nitrogen, pH and flow meter at the outlet in real time for 24 hours, and provides accurate water quality data. The treated tail water that meets the standard is pumped to the wetland water supplementing port through the water supplementing pipe and the water pump is arranged in the buffer tank (7) to avoid the hydraulic scouring around the water supplementing port by arranging the buffer grid at the wetland water supplementing port.

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