Efficient green zero-discharge construction method for slurry shield slurry

Abstract

The invention provides an efficient green zero-discharge construction method for slurry of a slurry shield, and relates to the technical field of slurry shields.The construction method comprises the steps of slurry bucket groove construction, high-quality slurry mixing, slurry-water separation treatment, new slurry preparation and slurry emergency treatment. The treated slurry can be recycled, so that the generation of waste slurry is effectively avoided; the geotextile tube bag can treat waste mud when mud water treatment equipment breaks down or operates in an overload mode, it is guaranteed that the shield tunneling machine conducts continuous tunneling and fast passing when the shield tunneling machine penetrates through a risk source, and the reliability of a shield is improved; by the adoption of the split mounting type barrel groove structure, construction is convenient, materials can be recycled, and the slurry leakage risk is avoided; according to the method, efficient and continuous tunneling of the slurry shield in a complex environment is achieved through the method of combining the modular bucket groove structure, the green muddy water treatment process and the geotextile pipe bag treatment.

Description

Technical Field

[0001] This invention relates to the field of slurry shield tunneling technology, and in particular to a high-efficiency, green, zero-discharge construction method for slurry shield tunneling. Background Technology

[0002] In the process of slurry balance shield tunneling, high-performance bentonite slurry is required to maintain the stability of the excavation face, which generates a large amount of waste slurry. If the waste slurry is not properly treated, it will not only waste resources and increase the cost of shield tunneling, but also endanger the surrounding ecological environment. Green and environmentally friendly slurry treatment equipment and technology and green and environmentally friendly waste slurry treatment process have become key factors to ensure green construction and high-speed shield tunneling. Summary of the Invention

[0003] The purpose of this invention is to address the above problems by providing a highly efficient, green, zero-discharge construction method for slurry shield tunneling, comprising: Construction of mud and water tank: Multiple sets of arc-shaped plates are spliced ​​together, and sealing material is placed between two adjacent arc-shaped plates in each set to obtain a sedimentation tank, a liquid storage tank, a new slurry tank and a preparation tank; High-quality mud mixing: High-quality mud is prepared by mixing environmentally friendly slurry agents, bentonite and water, and then the high-quality mud is delivered into the tunnel boring machine; Slurry separation treatment: The waste slurry discharged by the tunnel boring machine is screened through slurry treatment equipment to obtain first slurry and first particles. The first slurry and the first particles are discharged to the sedimentation tank and the slag yard respectively. After the first slurry in the sedimentation tank settles, the supernatant is transported to the conditioning tank. New slurry preparation: Prepare bentonite slurry and transport it to the preparation tank, prepare new slurry in the preparation tank and transport it into the tunnel boring machine; Emergency treatment of mud: If the mud and water treatment equipment malfunctions or is overloaded, or if the specific gravity of the waste mud exceeds the first set value, the waste mud is transported to a geotextile bag, and the waste mud is filtered through the geotextile bag to obtain clean water, which is then transported to the storage tank.

[0004] According to the technical solutions provided in some embodiments of the present invention, the construction method further includes: If the specific gravity of the first slurry in the sedimentation tank exceeds the second set value, the first slurry is concentrated to obtain slurry, clear water, slag and mud cake; the slurry and clear water are transported to the storage tank, and the slag and mud cake are discharged to the slag yard.

[0005] According to certain embodiments of the present invention, the step of screening the waste mud discharged from the tunnel boring machine using a mud and water treatment device to obtain a first mud and a first particle, and discharging the first mud and the first particle to the sedimentation tank and the slag yard respectively, includes: The waste mud is subjected to vibratory screening to obtain primary mud and particles with a diameter greater than 2 mm, and the particles with a diameter greater than 2 mm are discharged to the slag yard. The initial screening slurry is centrifuged to obtain the first slurry and particles with a particle size of 20μm-2mm, and the first slurry is then transported to the sedimentation tank. The particles with a diameter of 20μm-2mm are dehydrated and discharged into the slag yard.

[0006] According to the technical solutions provided in certain embodiments of the present invention, the process of concentrating the first mud slurry to obtain slurry, clear water, slag, and mud cake includes: A flocculant is added to the first slurry. After the first slurry separates into layers, the upper layer of the first slurry is centrifuged to obtain the slurry and the slag. The lower layer of the first slurry is filtered to obtain clear water and the mud cake.

[0007] According to the technical solutions provided in some embodiments of the present invention, the mud and water treatment equipment includes: A pre-screening device, the inlet of which is connected to the tunnel boring machine, is used to screen out particles with a diameter greater than 2mm from the waste mud. A slurry storage device, the input end of which is connected to the outlet of the pre-screening device, is used to receive and store the slurry processed by the pre-screening device. A cyclone separator is provided, the input end of which is connected to the output end of the slurry storage device. The cyclone separator is used to centrifuge the slurry in the slurry storage device to obtain the first slurry and particles with a particle size of 20μm-2mm. A dewatering device, the input end of which is connected to the overflow port of the cyclone device, is used to dewater the particles with a particle size of 20μm-2mm.

[0008] According to the technical solutions provided by certain embodiments of the present invention, the geotextile tubes are provided in multiple groups, and the multiple groups of geotextile tubes are arranged on the drainage layer, with multiple geotextile tubes in each group stacked in the vertical direction.

[0009] According to the technical solutions provided in certain embodiments of the present invention, The slurry storage device includes a first slurry storage tank and a second slurry storage tank, wherein the first slurry storage tank is connected to the liquid outlet of the pre-screening device. The hydrocyclone device includes a first hydrocyclone and a second hydrocyclone. The inlet of the first hydrocyclone is connected to the first slurry storage tank via a third slurry pump. The first hydrocyclone is used to separate particles with a diameter of 45μm-2mm in the slurry in the first slurry storage tank, and the particles are discharged from the bottom outlet of the first hydrocyclone. The overflow outlet of the first hydrocyclone is connected to the second slurry storage tank. The inlet of the second hydrocyclone is connected to the second slurry storage tank via a fourth slurry pump. The second hydrocyclone is used to separate particles with a diameter of 20μm-45μm in the slurry in the second slurry storage tank, and the particles are discharged from the bottom outlet of the second hydrocyclone. The overflow outlet of the second hydrocyclone is connected to the sedimentation tank.

[0010] According to the technical solutions provided in some embodiments of the present invention, the dehydration device includes: The first vibrating screen is set corresponding to the underflow port of the first hydrocyclone, and the first vibrating screen is used to screen out the moisture in the particles discharged from the underflow port of the first hydrocyclone. The second vibrating screen is set corresponding to the underflow port of the second hydrocyclone. The second vibrating screen is used to screen out the moisture in the particles discharged from the underflow port of the second hydrocyclone.

[0011] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention provides a highly efficient, green, zero-discharge construction method for slurry in slurry shield tunneling, including slurry tank construction, high-quality slurry mixing, slurry separation treatment, fresh slurry preparation, and emergency slurry treatment. By screening the waste slurry generated by the tunnel boring machine, solid particles in the slurry can be separated. The treated slurry can be recycled to prepare fresh slurry. The solid particles, after dehydration, are discharged to the slag yard and can be graded according to particle size for reuse. Through the above operations, the generation of waste slurry can be effectively avoided, which not only prevents resource waste but also saves on shield construction costs. At the same time, geotextile bags can handle the waste slurry discharged by the tunnel boring machine when the slurry treatment equipment malfunctions or is overloaded. Mud, when the tunnel boring machine (TBM) passes through a risk source, ensures continuous and rapid tunneling, reducing construction risks and improving the reliability of the TBM. The use of a modular tank structure facilitates construction and allows for material reuse, while avoiding the leakage risks of traditional mud pit structures, thus achieving green construction. By constructing sedimentation tanks, storage tanks, fresh mud tanks, and preparation tanks using modular arc-shaped plates, and dividing the mud treatment process into clearly defined functional modules such as "mud-water separation," "fresh mud preparation," and "emergency treatment," a refined, integrated, modular mud treatment system with risk response capabilities is constructed using a specific combination sequence, graded screening, and directional return path for treated materials. Slurry shield tunneling is mostly carried out in clay strata. Due to the high density of slurry, pumps may fail to extract the water. In such cases, slurry separation treatment can be omitted. Instead, the waste slurry generated during shield tunneling can be directly discharged into geotextile bags, where the slurry's gravity and pressure will separate the slurry from the water. This application achieves efficient, continuous, and uninterrupted tunneling of slurry shield tunneling in complex environments by combining a modular bucket structure, a green slurry treatment process, and geotextile bag treatment.

[0012] It should be understood that the descriptions of technical features, technical solutions, beneficial effects, or similar language in this invention do not imply that all features and advantages can be achieved in any single embodiment. Rather, it is understood that the description of a feature or beneficial effect means that a specific technical feature, technical solution, or beneficial effect is included in at least one embodiment. Therefore, the descriptions of technical features, technical solutions, or beneficial effects in this specification do not necessarily refer to the same embodiment. Furthermore, the technical features, technical solutions, and beneficial effects described in the embodiments of this invention can be combined in any suitable manner. Those skilled in the art will understand that embodiments can be implemented without one or more specific technical features, technical solutions, or beneficial effects of a particular embodiment. In other embodiments, additional technical features and beneficial effects may be identified in specific embodiments that do not embody all embodiments. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 A schematic diagram of a high-efficiency, green, zero-discharge construction method for slurry shield tunneling provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the slurry treatment equipment and slurry concentration equipment in a high-efficiency, green, zero-discharge construction method for slurry shield tunneling provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of the emergency module in a high-efficiency, green, zero-discharge construction method for slurry shield tunneling provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the geotextile bag stacking structure for a high-efficiency, green, zero-discharge construction method for slurry shield tunneling provided in an embodiment of the present invention.

[0015] The text labels in the image represent: 1. Slurry treatment equipment; 2. Slurry thickening equipment; 3. Tunnel boring machine; 4. Drainage layer; 5. Geotextile tubes; 6. Inlet pipe; 7. Drain pipe; 11. Pre-screening device; 12. First slurry storage tank; 13. Second slurry storage tank; 14. First hydrocyclone; 15. Second hydrocyclone; 16. First vibrating screen; 17. Second vibrating screen; 21. Centrifuge; 22. Filter press; 31. Sedimentation tank; 32. Storage tank; 33. Fresh slurry tank; 34. Conditioning tank. Detailed Implementation

[0016] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. This description is merely illustrative and explanatory, and should not be construed as limiting the scope of protection of the present invention in any way. Specifically, the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the scope of protection of the present invention.

[0017] It should be noted that similar reference numerals and letters in the following figures denote 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 "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatuses.

[0018] It should be noted that a slurry-balanced shield tunneling machine is a tunnel boring machine that uses pressurized slurry (usually a mixture of bentonite and water) to support the excavation face, maintain the stability of the tunnel working face, and simultaneously discharge the excavated soil in fluid form. It injects slurry under certain pressure into a sealed chamber in front of the support ring, so that the slurry forms a mud film on the excavation face to support the soil on the front. Then, the cutterhead installed at the front of the shield cuts the mud film on the surface of the soil. The excavated soil mixes with the working slurry to form a high-density slurry (i.e., waste slurry), which is discharged from the shield machine. Because the waste slurry carries a large number of solid particles, it can easily cause serious harm to the environment and therefore must be properly disposed of.

[0019] Please refer to Figure 1 This is a schematic diagram of a high-efficiency, green, zero-discharge construction method for slurry shield tunneling provided by an embodiment of the present invention. The construction method includes: Construction of mud and water tank: Multiple sets of arc-shaped plates are spliced ​​together, and sealing material is placed between two adjacent arc-shaped plates in each set to obtain sedimentation tank, liquid storage tank, new slurry tank and preparation tank; Specifically, the sedimentation tank 31, storage tank 32, new slurry tank 33, and preparation tank 34 have the same structure, each including multiple arc-shaped plates connected in sequence, with sealing material between adjacent arc-shaped plates. The sedimentation tank 31, storage tank 32, new slurry tank 33, and preparation tank 34 are all located in the mud tank area. The ground of the mud tank area is hardened with C30 ground as the foundation, and circular steel plates are laid underneath for the tank construction. Each tank is composed of arc-shaped plates, which are connected by expansion bolts. The joints between adjacent arc-shaped plates are treated to prevent water seepage by embedding sealant and rubber gaskets. Multiple sedimentation tanks 31 are located at the top of the mud tank area, and the sedimentation tanks 31 are connected in sequence. The preparation tank 34 is located at the bottom of the mud tank area, and each preparation tank 34 is equipped with a stirrer.

[0020] High-quality mud mixing: High-quality mud is prepared by mixing environmentally friendly mud-making agents, bentonite and water, and then transported into the tunnel boring machine. Specifically, during construction, in order to reduce the environmental pollution caused by mud, a new type of biodegradable shield tunneling special slurry agent and bentonite can be used to replace the traditional mud mixing scheme of bentonite, soda ash and CMC, which saves bentonite and also reduces environmental pollution.

[0021] Slurry separation treatment: The waste slurry discharged from the tunnel boring machine is screened and treated by slurry treatment equipment to obtain the first slurry and the first particles. The first slurry and the first particles are discharged to the sedimentation tank and the slag yard respectively. After the first slurry in the sedimentation tank settles, the clear liquid on the top layer is transported to the conditioning tank. Specifically, a sludge discharge pipeline connects the sludge treatment equipment 1 and the tunnel boring machine 3. Driven by a sludge discharge pump, the waste sludge enters the sludge treatment equipment 1 through the sludge discharge pipeline for treatment. The sludge treatment equipment 1 can perform multi-stage screening of the waste sludge according to different soil particle diameters, forming large-particle soil and sand and sludge containing small particles, namely the aforementioned first particles and first sludge. The first particles are particles with a diameter of 20μm-300mm, and the first sludge is the waste sludge after removing particles with a diameter of 20μm-300mm. The first output end of the sludge treatment equipment 1 is connected to the inlet of the sedimentation tank 31. The first sludge enters the sedimentation tank 31 through the first output end for sedimentation. The overflow port of the sedimentation tank 31 is connected to the conditioning tank 34, and the clear liquid above the sedimented first sludge enters the conditioning tank 34. The first particles are discharged to the slag yard through the second output end and can be directly transported by a transport vehicle.

[0022] New slurry preparation: Prepare bentonite slurry and transport it to the preparation tank, prepare new slurry in the preparation tank and transport it into the tunnel boring machine; Specifically, the storage tank 32 is used to store clean water. The outlet of the storage tank 32 is connected to the new slurry tank 33 and the conditioning tank 34 through the first clean water pump and the second clean water pump, respectively. The new slurry tank 33 is also equipped with a stirrer for preparing bentonite slurry by using bentonite and clean water. The new slurry tank 33 is also connected to the conditioning tank 34 through the first delivery pump. The bentonite slurry is stirred together with clean water and the upper clear liquid after the first mud sedimentation in the conditioning tank 34 to prepare new slurry, and then transported to the tunnel boring machine 3.

[0023] Emergency treatment of mud: If the mud and water treatment equipment malfunctions or is overloaded, or if the specific gravity of the waste mud exceeds the first set value, the waste mud is transported to the geotextile bag, and the waste mud is filtered through the geotextile bag to obtain clean water, which is then transported to the storage tank. Furthermore, multiple sets of geotextile bags 5 are provided, and multiple sets of geotextile bags 5 are arranged on the drainage layer 4, with multiple geotextile bags 5 in each set stacked vertically. For details, please refer to Figure 3 and Figure 4 When the specific gravity of the waste mud exceeds 1.3 t / m³3 When the shield tunneling muck is difficult to remove (i.e., the first set value mentioned above), or the slurry treatment equipment 1 malfunctions and the slurry treatment capacity cannot meet the requirements of the shield tunneling slurry, or when the shield tunneling needs to continue tunneling without stopping when passing through a risk source, the waste slurry generated during shield tunneling can be directly discharged to the geotextile bag 5 area for dehydration and solidification; a drainage layer 4 is formed by laying pebbles, and multiple sets of geotextile bags 5 are laid on the drainage layer 4. Each set of multiple geotextile bags 5 is stacked, with the upper geotextile bag 5 being 2m smaller on each side than the lower geotextile bag 5 to ensure that the bag is filled. The structure is stable; the geotextile tube 5 is connected to the tunnel boring machine 3 through the liquid inlet pipe 6. The liquid inlet pipe 6 is equipped with a gate valve and a distributor to allow multiple geotextile tubes 5 to be filled simultaneously. When the mud generated by the tunnel boring machine is discharged into the geotextile tube 5, the filtration structure formed by the woven form of the geotextile tube 5 and the liquid pressure inside the bag cause the mud to be completely solidified in the geotextile tube 5. The clean water filtered by the geotextile tube 5 is transported to the storage tank 32 through the drain pipe 7 and can be reused without mud leakage. Compared with the traditional dewatering method, it has the advantages of fast dewatering speed, small space occupation, and no secondary pollution.

[0024] By screening the waste slurry generated by the tunnel boring machine (TBM) 3, solid particles can be separated from the slurry. The treated slurry can be recycled to prepare new slurry. The solid particles, after dewatering, are discharged to the slag yard and can be graded according to particle size for reuse. This process effectively avoids the generation of waste slurry, preventing resource waste and saving on tunnel boring machine (TBM) costs. Simultaneously, the geotextile bag 5 can handle the slurry discharged from the TBM 3 when the slurry treatment equipment 1 malfunctions or is overloaded. When the TBM 3 passes through a risk source, it can ensure continuous and rapid tunneling, reducing construction risks and improving efficiency. The reliability of the tunnel boring machine is improved; by adopting a modular tank structure, construction is convenient and materials can be reused, while avoiding the leakage risk of traditional mud pit structures, thus achieving green construction; by using modular arc plates to construct sedimentation tank 31, liquid storage tank 32, fresh mud tank 33, and conditioning tank 34, and dividing the mud treatment process into clear functional modules such as "mud-water separation", "fresh mud conditioning", and "emergency treatment", a refined, integrated, modular mud treatment system with risk response capabilities is constructed by using a specific combination sequence, graded screening, and directional return path of treated materials.

[0025] Furthermore, to address the difficulties in transporting and disposing of construction waste from slurry balance shield tunnels in urban areas, a waste particle size classification and utilization technology is adopted. Large-particle waste can be used for engineering materials; fine-particle waste can be combined with epoxy resin, initiator, silica nano-ions, and other inorganic components to produce a highly concentrated, environmentally friendly, and high-strength curing agent. It can also be applied to the self-compacting backfilling technology of fluidized solidified soil foundation trenches, or to the manufacture of non-fired paving bricks, thereby realizing the resource utilization of construction waste from slurry balance shield tunnels.

[0026] In a preferred embodiment, the construction method further includes: If the specific gravity of the first slurry in the sedimentation tank 31 exceeds the second set value, the first slurry is concentrated to obtain slurry, clear water, slag and mud cake; the slurry and clear water are transported to the storage tank 32, and the slag and mud cake are discharged to the slag yard. Specifically, when the specific gravity of the first slurry in sedimentation tank 31 exceeds 1.2 t / m³ 3 When the second set value is reached (i.e., the above-mentioned second set value), the first mud in the sedimentation tank 31 is concentrated by the mud-water thickening device 2. The clear water and slurry obtained after the treatment are transported to the storage tank 32 for the preparation of new slurry, and the resulting slag and mud cake are discharged to the slag yard.

[0027] Furthermore, the mud-water thickening equipment 2 includes a centrifuge 21 and a filter press 22. The inlet of the centrifuge 21 is connected to the sedimentation tank 31 through a first slurry pump for centrifugal separation of the first mud to obtain slurry and slag. The inlet of the filter press 22 is connected to the sedimentation tank 31 through a second slurry pump for filter pressing of the first mud to obtain clear water and mud cake. Specifically, as the number of tunneling rings increases, the specific gravity and viscosity of the first slurry in the settling tank 31 will increase. When the specific gravity or viscosity of the first slurry does not meet the construction requirements, a centrifuge 21 and a filter press 22 are used for further treatment. A mobile slurry pump is installed in the settling tank 31. When the specific gravity of the first slurry in the settling tank 31 exceeds 1.2 t / m 3When the viscosity exceeds 24s, the first slurry is pumped to the storage tank of the slurry thickening device 2 using a mobile slurry pump. Then, a flocculant (polyacrylamide (PAM)) at a ratio of 3-5‰ is added to the storage tank and thoroughly stirred. After the flocculant settles, the first slurry in the storage tank separates into layers. The upper layer of slurry with a lower specific gravity is processed by centrifuge 21, while the lower layer of slurry with a higher specific gravity is processed by filter press 22. To improve the processing efficiency of centrifuge 21 and filter press 22, different methods are needed to adjust the viscosity, pH value, and other indicators of the first slurry according to different situations. The slurry viscosity has a significant impact on the tunnel boring speed and slurry treatment. The conventional method is to add water to dilute the slurry with higher viscosity. When there are many clay particles in the slurry and they are finely dispersed, calcium can be added. Dilute with lime-tannin alkali solution or fresh slurry and water (provided the water loss is permissible); when high temperature causes viscosity to increase, a high-temperature diluent (such as iron-chromium salts) can be added; when the slurry specific gravity is high and causes viscosity to increase, sodium tannate can be added; when the pH value of the slurry is controlled within a suitable range, the slurry shear stress is low, the water loss is low, and the performance is relatively stable. At the same time, the pH value has a significant flocculation effect on the slurry, so controlling the pH value is very important for slurry treatment. When the pH value is too high, tannic acid, tannin powder, or lignite powder can be added; when too much tannic acid causes the slurry pH value to decrease, a high-alkali ratio coal alkali solution can be added; when the slurry viscosity is high, caustic soda solution or a high-alkali ratio sodium tannate can be added; when the slurry water loss is high, a small amount of CMC can be added.

[0028] The slurry with a lower specific gravity at the top is pumped into centrifuge 21 by the first slurry pump. When the pusher of centrifuge 21 rotates, the slurry with a lower specific gravity is dispersed into the drum from the feed port. The coarse particles in the slurry settle on the inner surface of the drum. The blades of the pusher rotate continuously, pushing the slag formed by the particles toward the solid material outlet. The drum generates high centrifugal force, causing the slurry to form a slurry pool inside the drum. The free liquid and finer particles flow to the other end of centrifuge 21 and are discharged as slurry through the overflow weir. Particles with a diameter of 5µm or more in the slurry are separated and fall into the slag yard. Its moisture content is less than 40%, and it can be directly loaded onto trucks for slag discharge. The separated slurry is transported to the mixing tank 34 for remixing new slurry. The heavier slurry at the bottom is pumped into the storage tank of the filter press 22 by the second slurry pump. After being stirred in the storage tank, it enters the filter chamber of the filter press 22. The solids in the slurry are intercepted by the filter cloth and particles, and the liquid is discharged. Then, the diaphragm pressing is carried out to reduce the moisture content. The filtered solids form a mud cake with a moisture content of less than 25%, which can also be directly loaded onto trucks for slag discharge. The separated clear water is transported to the conditioning tank 34 for remixing new slurry.

[0029] Furthermore, the storage tank 32 includes a clear water tank and a centrifuge feeding tank. The clear water tank is used to store clear water, and the centrifuge feeding tank is used to store the slurry produced by the centrifuge 21. The new slurry tank 33 is used to store sewage during the initial shield tunneling and is used to mix bentonite slurry after the shield tunneling begins. The conditioning tank 34 serves as a mud conditioning zone, used to neutralize the bentonite slurry and the slurry produced by the centrifuge 21 to make new slurry, which is then transported into the shield machine 3. A storage tank and a chemical dosing tank are also provided. The storage tank is used to store bentonite. The bentonite and the clear water in the clear water tank enter the new slurry tank 33 together and are stirred to form bentonite slurry. The chemical dosing tank is used to add a regulator to neutralize the slurry produced by the centrifuge 21.

[0030] In a preferred embodiment, the mud and water treatment device 1 includes: The pre-screening device 11 has its inlet connected to the tunnel boring machine 3. The pre-screening device 11 is used to screen out particles with a diameter greater than 2 mm in the waste mud. The slurry storage device has its input end connected to the outlet of the pre-screening device 11. The slurry storage device is used to receive and store the slurry processed by the pre-screening device 11. The cyclone device has its input end connected to the output end of the slurry storage device. The cyclone device is used to centrifuge the slurry in the slurry storage device to obtain the first slurry and particles with a particle size of 20μm-2mm. The dewatering device has its input end connected to the overflow port of the cyclone device and is used to dewater particles with a particle size of 20μm-2mm.

[0031] Furthermore, The slurry storage device includes a first slurry storage tank 12 and a second slurry storage tank 13. The first slurry storage tank 12 is connected to the outlet of the pre-screening device 11. The hydrocyclone device includes a first hydrocyclone 14 and a second hydrocyclone 15. The inlet of the first hydrocyclone 14 is connected to the first slurry storage tank 12 via a third slurry pump. The first hydrocyclone 14 is used to separate particles with a diameter of 45μm-2mm in the slurry in the first slurry storage tank 12 and discharge them through the underflow port of the first hydrocyclone 14. The overflow port of the first hydrocyclone 14 is connected to the second slurry storage tank 13. The inlet of the second hydrocyclone 15 is connected to the second slurry storage tank 13 via a fourth slurry pump. The second hydrocyclone 15 is used to separate particles with a diameter of 20μm-45μm in the slurry in the second slurry storage tank 13 and discharge them through the underflow port of the second hydrocyclone 15. The overflow port of the second hydrocyclone 15 is connected to the sedimentation tank 31.

[0032] For details, please refer to Figure 2The sludge treatment equipment 1 is installed on a sludge treatment platform, which is a three-layer steel structure. Multiple first hydrocyclones 14 and multiple second hydrocyclones 15 are integrated and installed on the top layer. A pre-screening device 11 and a dewatering device are installed on the middle layer, with the dewatering device located below the first hydrocyclones 14 and multiple second hydrocyclones 15. A first slurry storage tank 12 and a second slurry storage tank 13 are installed on the bottom layer, with the first slurry storage tank 12 located below the pre-screening device 11 and the second slurry storage tank 13 located below the dewatering device. The waste sludge discharged from the tunnel boring machine 3... Driven by the slurry pump, the slurry first enters the buffer tank for decompression through the sludge discharge pipeline, and then enters the pre-screening device 11. After the waste slurry is vibrated and screened, particles with a diameter of 2mm or larger are screened out and placed in the slag yard. The moisture content of the particles after vibrating screening is less than 25%, and they can be directly transported by vehicle. The screened waste slurry enters the first slurry storage tank 12. The screen size of the pre-screening device 11 can be selected according to the particle content of the stratum. The geological conditions of the tunnel boring machine 3 excavation section are detected to clarify the slag composition of the tunnel boring stratum. Then, based on the size of the slag particles to be screened, select the appropriate screen mesh size, wire diameter, aperture, diameter, material, and effective screen surface, etc., to meet the screening requirements. The slurry in the first storage tank 12 enters the first hydrocyclone 14 under the drive of the third slurry pump. The first hydrocyclone 14 separates the waste slurry and particles with a diameter of 45μm-2mm through centrifugal action. The waste slurry flows from the overflow port of the first hydrocyclone 14 into the second storage tank 13, while the particles with a diameter of 45μm-2mm flow from the underflow port of the first hydrocyclone 14 into the dewatering device. The slurry is dewatered and then discharged to the slag yard, with a moisture content of less than 25%. The slurry in the second storage tank 13 is driven by the fourth slurry pump into the second hydrocyclone 15. The second hydrocyclone 15 separates the waste slurry and particles with a particle size of 20μm-45μm. After separation, the first slurry enters the sedimentation tank 31 through the overflow port of the second hydrocyclone 15, while the particles with a particle size of 45μm-2mm enter the dewatering device through the underflow port of the second hydrocyclone 15 for dewatering treatment and then discharged to the slag yard, with a moisture content of less than 25%.

[0033] Furthermore, the dehydration device includes: The first vibrating screen 16 is set to correspond to the underflow port of the first hydrocyclone 14. The first vibrating screen 16 is used to screen out the moisture in the particles discharged from the underflow port of the first hydrocyclone 14. The second vibrating screen 17 is set to correspond to the underflow port of the second hydrocyclone 15. The second vibrating screen 17 is used to screen out the moisture in the particles discharged from the underflow port of the second hydrocyclone 15.

[0034] Specifically, the first vibrating screen 16 and the second vibrating screen 17 are both set at the bottom of the mud and water treatment platform. The first vibrating screen 16 is set with multiple first hydrocyclones 14, and the second vibrating screen 17 is set with multiple second hydrocyclones 15. The first vibrating screen 16 and the second vibrating screen 17 can process particles with a diameter of 20µm or more, which are used to dewater the particles and discharge them to the slag yard so that they meet the standard for direct transportation.

[0035] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. The above descriptions are only preferred embodiments of the present invention. It should be noted that due to the limitations of textual expression, and the objective existence of infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of the present invention.

Claims

1. A high-efficiency, green, zero-discharge construction method for slurry shield tunneling, characterized in that, include: Construction of mud and water tank: Multiple sets of arc-shaped plates are spliced ​​together, and sealing material is placed between two adjacent arc-shaped plates in each set to obtain a sedimentation tank, a liquid storage tank, a new slurry tank and a preparation tank; High-quality mud mixing: High-quality mud is prepared by mixing environmentally friendly slurry agents, bentonite and water, and then the high-quality mud is delivered into the tunnel boring machine; Slurry separation treatment: The waste slurry discharged by the tunnel boring machine is screened through slurry treatment equipment to obtain first slurry and first particles. The first slurry and the first particles are discharged to the sedimentation tank and the slag yard respectively. After the first slurry in the sedimentation tank settles, the supernatant is transported to the conditioning tank. New slurry preparation: Prepare bentonite slurry and transport it to the preparation tank, prepare new slurry in the preparation tank and transport it into the tunnel boring machine; Emergency treatment of mud: If the mud and water treatment equipment malfunctions or is overloaded, or if the specific gravity of the waste mud exceeds the first set value, the waste mud is transported to a geotextile bag, and the waste mud is filtered through the geotextile bag to obtain clean water, which is then transported to the storage tank.

2. The efficient, green, zero-discharge construction method for slurry shield tunneling according to claim 1, characterized in that, The construction method also includes: If the specific gravity of the first slurry in the sedimentation tank exceeds the second set value, the first slurry is concentrated to obtain slurry, clear water, slag and mud cake; the slurry and clear water are transported to the storage tank, and the slag and mud cake are discharged to the slag yard.

3. The efficient, green, zero-discharge construction method for slurry shield tunneling according to claim 1, characterized in that, The process of screening the waste mud discharged from the tunnel boring machine using a mud and water treatment device to obtain a first mud and a first particle, and discharging the first mud and the first particle to the sedimentation tank and the slag yard respectively, includes: The waste mud is subjected to vibratory screening to obtain primary mud and particles with a diameter greater than 2 mm, and the particles with a diameter greater than 2 mm are discharged to the slag yard. The initial screening slurry is centrifuged to obtain the first slurry and particles with a particle size of 20μm-2mm, and the first slurry is then transported to the sedimentation tank. The particles with a diameter of 20μm-2mm are dehydrated and discharged into the slag yard.

4. The efficient, green, zero-discharge construction method for slurry shield tunneling according to claim 2, characterized in that, The process of concentrating the first mud slurry to obtain slurry, clear water, slag, and mud cake includes: A flocculant is added to the first slurry. After the first slurry separates into layers, the upper layer of the first slurry is centrifuged to obtain the slurry and the slag. The lower layer of the first slurry is filtered to obtain clear water and the mud cake.

5. The efficient, green, zero-discharge construction method for slurry shield tunneling according to claim 1, characterized in that, The mud and water treatment equipment (1) includes: A pre-screening device (11) is provided, the inlet of which is connected to the tunnel boring machine (3). The pre-screening device (11) is used to screen out particles with a diameter greater than 2 mm in the waste mud. The slurry storage device is connected to the outlet of the pre-screening device (11) at its input end. The slurry storage device is used to receive and store the slurry processed by the pre-screening device (11). A cyclone separator is provided, the input end of which is connected to the output end of the slurry storage device. The cyclone separator is used to centrifuge the slurry in the slurry storage device to obtain the first slurry and particles with a particle size of 20μm-2mm. A dewatering device, the input end of which is connected to the overflow port of the cyclone device, is used to dewater the particles with a particle size of 20μm-2mm.

6. The efficient, green, zero-discharge construction method for slurry shield tunneling according to claim 1, characterized in that, The geotextile tubes (5) are provided in multiple sets, and the multiple sets of geotextile tubes (5) are arranged on the drainage layer (4), with multiple geotextile tubes (5) in each set stacked in the vertical direction.

7. The efficient, green, zero-discharge construction method for slurry shield tunneling according to claim 5, characterized in that, The slurry storage device includes a first slurry storage tank (12) and a second slurry storage tank (13), wherein the first slurry storage tank (12) is connected to the outlet of the pre-screening device (11); The hydrocyclone device includes a first hydrocyclone (14) and a second hydrocyclone (15). The inlet of the first hydrocyclone (14) is connected to the first slurry tank (12) through a third slurry pump. The first hydrocyclone (14) is used to separate particles with a diameter of 45μm-2mm in the mud in the first slurry tank (12) and discharge them through the bottom outlet of the first hydrocyclone (14). The overflow outlet of the first hydrocyclone (14) is connected to the second slurry tank (13). The inlet of the second hydrocyclone (15) is connected to the second slurry tank (13) through a fourth slurry pump. The second hydrocyclone (15) is used to separate particles with a diameter of 20μm-45μm in the mud in the second slurry tank (13) and discharge them through the bottom outlet of the second hydrocyclone (15). The overflow outlet of the second hydrocyclone (15) is connected to the sedimentation tank (31).

8. The efficient, green, zero-discharge construction method for slurry shield tunneling according to claim 7, characterized in that, The dehydration device includes: The first vibrating screen (16) is set to correspond to the underflow port of the first hydrocyclone (14). The first vibrating screen (16) is used to screen out the moisture in the particles discharged from the underflow port of the first hydrocyclone (14). The second vibrating screen (17) is set to correspond to the underflow port of the second hydrocyclone (15). The second vibrating screen (17) is used to screen out the moisture in the particles discharged from the underflow port of the second hydrocyclone (15).

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