Tunneling machine for tunneling raw state slag soil and tunneling process thereof

Abstract

This invention discloses a tunnel boring machine (TBM) with uncontaminated soil, comprising a body, a soil chamber, a cutterhead, a drive system, and a soil removal system. The soil chamber is rotatably connected to the front end of the body, and the cutterhead is positioned at the front end of the soil chamber. The drive system and the soil removal system are located within the body, and the soil removal system discharges soil from the soil chamber. The cutterhead includes a leading cutter, a central column, and multiple spokes. The central column is coaxial with the soil chamber, and the drive system drives the central column to rotate. The multiple spokes are arranged around the outer periphery of the central column, with one end fixed to the central column and the other end inclined towards and fixed to the soil chamber. Multiple toothed cutters for scraping soil are provided on the spokes. The leading cutter is fixed at the front end of the central column. This invention can cut soil without soil modification or water addition, thus enabling the treatment of uncontaminated soil. A tunneling process using the uncontaminated soil TBM is also disclosed, which can achieve both tunneling operations and soil treatment, resulting in a significant reduction in overall construction costs.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine technology, and in particular to a tunnel boring machine with original muck soil and its tunneling process. Background Technology

[0002] Tunnel boring machines (TBMs) are mechanical devices used to excavate straight underground tunnels. With the rapid development of urban construction, various public utility pipelines, such as urban sewers, gas pipelines, power cable pipelines, and communication cable pipelines, frequently need to cross roads, rivers, and other sections. The pipe jacking method has now been developed to the point where it can be used for long-distance construction in densely built-up urban areas, for building underground sewers, gas pipelines, and other facilities.

[0003] Currently, tunneling machines are mainly divided into two categories: earth pressure balance tunneling machines (EPBs) and hydraulic pressure balance tunneling machines (HPBs). EPBs require the addition of modifiers such as bentonite to maintain soil plasticity before tunneling operations can commence. This type of machine suffers from increased material and labor costs, altered chemical properties of the modified excavated soil making direct backfilling or reuse difficult, and significant power consumption due to the need for continuous high-pressure soil removal via the screw conveyor. Furthermore, it is prone to pressure imbalance in highly permeable strata (such as sand layers), leading to surface subsidence. While hydraulic pressure balance tunneling machines offer advantages such as simple structure and lower cost, they consume large amounts of water during construction, and slurry removal is challenging. Construction in arid regions faces significant difficulties, requiring the construction of slurry separation stations and pipeline systems, resulting in a large site footprint and significant limitations imposed by objective conditions.

[0004] Therefore, there is an urgent need to design a new type of tunneling machine that can achieve waterless operation and direct discharge of original excavated soil. Summary of the Invention

[0005] This invention provides a tunnel excavator with original soil excavation and its excavation process to solve the above-mentioned technical problems.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: A tunnel boring machine with original excavated soil includes: a body, a soil chamber, a cutterhead, a drive system, and a soil removal system; the soil chamber is rotatably connected to the front end of the body, the cutterhead is located at the front end of the soil chamber, the drive system and the soil removal system are located inside the body, and the soil removal system discharges soil from the soil chamber; the cutterhead includes: a leading cutter, a central column, and multiple spokes, the central column is coaxial with the soil chamber, the drive system drives the central column to rotate, the multiple spokes are arranged around the outer periphery of the central column, one end of the spokes is fixed to the central column, and the other end is inclined towards the soil chamber and fixed to the soil chamber; multiple toothed cutters for scraping soil are provided on the spokes; the leading cutter is fixed at the front end of the central column.

[0007] Preferably, the multiple spokes 33 are located on the edges of the regular pyramid.

[0008] Preferably, the opening ratio of the cutter head is 70% to 80%.

[0009] Preferably, multiple toothed cutters are arranged alternately on the spokes to form two rows of toothed cutters.

[0010] Preferably, the toothed cutter includes: a toothed cutter mounting part, a toothed cutter support part, and a plurality of cutter teeth. The toothed cutter mounting part is detachably connected to the spoke. The toothed cutter support part is wedge-shaped and gradually decreases in size from the end connected to the toothed cutter mounting part to the end away from the toothed cutter mounting part. The plurality of cutter teeth are spaced apart at the end of the toothed cutter support part away from the toothed cutter mounting part.

[0011] Preferably, the cutting tooth includes: a bottom surface, a bevel surface, a top surface, a vertical surface, and two side surfaces. The bottom surface is fixed on the cutting tooth support. The two side surfaces are positioned opposite each other on the bottom surface. The bevel surface and vertical surface are positioned opposite each other on the bottom surface and located between the two side surfaces. The bevel surface is located on the side facing the cutting tooth support. The top surface is positioned opposite the bottom surface. The top surface connects the bevel surface, vertical surface, and two side surfaces. The bottom surface, bevel surface, top surface, vertical surface, and two side surfaces form a closed solid. The cutting teeth are spaced 2-4 cm apart. The angle between the bevel surface and the bottom surface is 25°-35°. The top surface includes an arc-shaped surface.

[0012] Preferably, the advance cutter includes an advance cutter holder detachably connected to the end face of the central column and multiple advance cutter plates. The multiple advance cutter plates are fixedly mounted radially on the advance cutter holder, and the center of the assembly of the multiple advance cutter plates is higher than the surrounding area.

[0013] Preferably, the end face of the central column is a concave spherical surface, and the side of the advance tool holder facing the central column is a convex spherical surface, with the convex spherical surface of the advance tool holder engaging with the concave spherical surface of the central column.

[0014] Preferably, the drive system includes: a drive shaft, a central gear, and at least two sets of drivers. Each driver includes a drive gear and a motor that drives the drive gear to rotate. The drive shaft is rotatably connected to the housing. The drive shaft is coaxially connected to the central column. The central gear is coaxially fixed on the drive shaft. The drive gears of the at least two sets of drivers are arranged around the central gear and mesh externally. The angle between the axis of the drive gear and the axis of the drive shaft is 12° to 18°.

[0015] A tunneling process using the aforementioned tunnel boring machine with uncontaminated soil, characterized by the following steps: S1. The drive system controls the cutter head to rotate continuously at a low speed of 1~3 rpm, and the cutter head efficiently cuts the loess in contact with it to form loose original slag soil. S2. The excavated soil enters the soil chamber through the opening of the cutterhead, and the soil chamber transports the excavated soil to the soil discharge system as the cutterhead rotates. S3. The soil discharge system continuously transports the excavated soil to the tail of the tunneling machine at a preset speed, and the excavated soil falls into the soil hopper attached to the battery trailer. S4. After the slag bucket is full, it is transported to the starting well by a battery-powered vehicle, and the slag bucket is lifted out of the well opening and dumped to the slag storage point using hoisting equipment. S5. Empty slag hoppers are hoisted back to the bottom of the well by battery-powered trucks, which then transport the slag back for repeated dumping.

[0016] Beneficial effects: First, the tunnel excavator disclosed in this application pre-crushes the soil by setting a leading cutter, and then forms a conical structure through a central column and multiple spokes. It has the characteristics of high efficiency and low resistance, reduces the tunneling torque and the power demand, so that the soil can be cut without soil improvement or water addition, thereby realizing the discharge of original excavated soil.

[0017] Secondly, the tunneling process using a tunnel boring machine with original soil excavation disclosed in this application can realize tunneling operations and soil excavation treatment, thereby significantly reducing the overall construction cost. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a tunnel excavator with original soil and debris, as disclosed in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram showing the combination of the soil chamber, cutterhead, and drive system of a tunnel boring machine based on original muck soil, as disclosed in Embodiment 1 of the present invention. Figure 3 This is a schematic diagram of the soil chamber and cutterhead of a tunnel boring machine based on original muck soil, as disclosed in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the leading cutter of a tunnel excavator based on original muck soil, as disclosed in Embodiment 1 of the present invention. Figure 5 This is a schematic diagram of the connection between the central column and spokes of a tunnel excavator based on original excavated soil, as disclosed in Embodiment 1 of the present invention; Figure 6 This is a schematic diagram of the structure of a tunnel excavator based on original muck soil, as disclosed in Embodiment 1 of the present invention. Figure 7 This is a schematic diagram of the toothed cutter of a tunnel boring machine based on original excavated soil, as disclosed in Embodiment 1 of the present invention; Figure 8for Figure 7 A magnified view of part I.

[0020] In the diagram: 1. Body; 2. Soil chamber; 21. Soil retaining plate; 3. Cutter head; 31. Leading cutter; 311. Leading cutter holder; 312. Leading cutter plate; 32. Center column; 33. Spoke; 34. Toothed cutter; 341. Toothed cutter mounting part; 342. Toothed cutter support part; 343. Cutter tooth; 3431. Toothed bevel; 3432. Toothed top surface; 3433. Toothed side surface; 41. Drive shaft; 42. Center gear; 43. Drive gear; 44. Motor. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments 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, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1 A tunnel boring machine using original excavated soil and its tunneling technology, combined with Figures 1 to 8 As shown, it includes: a body 1, a soil chamber 2, a cutter head 3, a drive system, and a soil removal system; the soil chamber 2 is rotatably connected to the front end of the body 1, the cutter head 3 is located at the front end of the soil chamber 2, the drive system and the soil removal system are located inside the body 1, and the soil removal system discharges the soil from the soil chamber 2; the cutter head 3 includes: a pilot cutter 31, a central column 32, and multiple spokes 33, the central column 32 is coaxial with the soil chamber 2, the drive system drives the central column 32 to rotate, the multiple spokes 33 are arranged around the outer periphery of the central column 32, one end of the spokes 33 is fixed on the central column 32, and the other end is inclined towards the soil chamber 2 and fixed on the soil chamber 2; multiple toothed blades 34 for scraping soil are provided on the spokes 33; the pilot cutter 31 is fixed at the front end of the central column 32. This application pre-crushes the soil by setting a leading cutter 31, and then forms a conical structure through a central column 32 and multiple spokes 33. It has the characteristics of high efficiency and low resistance, reduces the tunneling torque and power demand, so that the soil can be cut without soil improvement or water addition, and thus the original state of the excavated soil can be discharged.

[0023] Preferably, multiple spokes 33 are located on the edges of a regular pyramid, and the multiple spokes 33 are arranged radially around the central column 32 and connected to the soil chamber 2. The multiple spokes 33 form a regular pyramid shape, so that the multiple spokes 33 together cut the soil and bear the entire excavation torque.

[0024] Specifically, there are six spokes 33 with an "M"-shaped cross-section. The grooves on their outer sides face the soil, allowing the slag to flow smoothly and naturally towards the discharge channel. The sides and back of the spokes 33 are rounded without any dead angles, eliminating space for slag adhesion and retention. The bending angle of the bending plate forming the groove in the middle is 105°-115°, effectively improving structural rigidity. In this embodiment, the spokes 33 are made of Q690D material with a bending angle of 110°, significantly enhancing the bending and torsional rigidity of the spokes 33.

[0025] Specifically, this application conducts a simulation study on the influence of the bending angle on the performance of spoke 33, as shown in Table 1 below.

[0026] Table 1 Simulation Test of Spoke Angle

[0027] The table above shows that a 120° bend leads to performance degradation, as excessive bending causes localized flange buckling, resulting in a 19% decrease in stiffness and a 27% increase in welding stress compared to 110°. A 100° bend causes excessive deformation of the spokes at the cutter head edge (>1.5mm), easily leading to positioning deviations in the tooth cutters. From a manufacturing perspective, bends >115° require thermoforming, increasing costs and hindering economic efficiency. Therefore, a spoke angle of 105°~115° is recommended.

[0028] Specifically, the ends of spokes 33 are positioned using a conical surface, and then torque is transmitted through rectangular anti-torsion keys to prevent fastener damage from shear forces. Finally, they are fixedly connected using high-strength bolts. This avoids welding connections, ensures high connection rigidity and installation accuracy, and allows for the replacement and maintenance of individual spokes 33.

[0029] Preferably, the opening ratio of the cutterhead 3 is 70% to 80%. This opening ratio, combined with the spokes 33, reduces the frictional resistance between the cutterhead 3 and the soil, eliminating the need for mud support and thus reducing equipment complexity and construction costs. In this embodiment, the diameter of the cutterhead 3 is 2020 mm, and the opening ratio is controlled at 75%.

[0030] Specifically, this application conducts a simulation study on the influence of the aperture ratio of the cutter head 3 on the performance of the cutter head 3, as shown in Table 2 below.

[0031] Table 2. Simulation test of open area ratio

[0032] As shown in the table above, an opening ratio between 70% and 80% offers a long service life, exceeding 100,000 cycles, with a soil throughput rate consistently above 80% and a blockage coefficient below 0.2, effectively guaranteeing both excavation speed and service life. A 65% opening ratio results in a soil throughput rate of only 65%, leading to an excessively low excavation speed, while an 85% opening ratio only provides a service life of 56,000 cycles, making it less economical. Therefore, an opening ratio of 70% to 80% can be set according to different excavation conditions.

[0033] Preferably, multiple toothed cutters 34 are staggered on the spokes 33 to form two rows of toothed cutters 34, each row arranged along the length of the spokes 33. Multiple toothed cutter mounting slots are staggered on the spokes 33, and each toothed cutter 34 is fixed in the corresponding toothed cutter mounting slot by bolts.

[0034] Specifically, the toothed cutter 34 on the spoke 33 near the soil chamber 2 serves as a side scraper. The toothed cutter 34 extends slightly beyond the outer diameter of the soil chamber 2, so that after the tunnel is scraped by the outermost toothed cutter 34, the tunnel body is uniform and smooth, greatly reducing the friction during the pipe jacking process.

[0035] Specifically, during the tunneling process, the toothed cutters 34 at different positions and heights cut into the soil sequentially, in batches, and gradually, avoiding the simultaneous contact of all cutters with the tunnel face at the same depth. This prevents the superposition of instantaneous cutting resistance and avoids the cutterhead 3 bearing peak impact loads. In traditional closed-panel cutterheads, the entire front of the panel is in full contact with, compressed, and subjected to sliding friction with the tunnel face soil during rotational cutting. A large area of ​​contact friction and shear surface is formed between the panel and the soil, resulting in enormous frictional resistance. At the same time, the closed panel causes the soil to be continuously compacted, adhered, and agglomerated in front of the cutterhead, further increasing the rotational resistance and torque of the cutterhead. This application employs a spoked cutterhead with a high open area ratio of 70%–80%. Only the spokes and a few reinforcing ribs contact the soil, resulting in a solid contact area that is only 20%–30% of that of a traditional closed cutterhead. There is no large-area panel compression friction between the cutterhead and the soil, allowing the excavated soil to flow smoothly into the soil chamber directly through the large openings. The absence of extensive sliding friction and compaction effects between the panel and the soil significantly reduces the cutterhead rotational resistance and tunneling torque. Due to this significant reduction in frictional resistance and cutterhead torque, the cutterhead no longer relies on water or mud for lubrication and drag reduction during cutting and excavation, fundamentally eliminating dependence on mud lubrication and soil improvement. Furthermore, one of the core purposes of traditional tunneling machines using mud support is to reduce cutterhead friction, cool the cutting tools, and prevent soil adhesion and clumping. This application optimizes the structure to achieve low friction, no cutting tool sticking, no clumping, and smooth excavation, eliminating the need to rely on mud pressure and lubrication to maintain tunneling. Therefore, the mud circulation system, mud-water support system, and soil improvement system can be completely eliminated, significantly simplifying the equipment structure, reducing construction energy consumption and material costs, and truly achieving safe tunneling under conditions of no water, no mud, and no soil improvement.

[0036] Preferably, the toothed cutter 34 includes: a toothed cutter mounting part 341, a toothed cutter support part 342, and a plurality of cutter teeth 343. The toothed cutter mounting part 341 is detachably connected to the spoke 33. The toothed cutter support part 342 is wedge-shaped and gradually decreases in size from the end connected to the toothed cutter mounting part 341 to the end away from the toothed cutter mounting part 341. The plurality of cutter teeth 343 are spaced apart at the end of the toothed cutter support part 342 away from the toothed cutter mounting part 341.

[0037] Preferably, the cutting tooth 343 includes: a bottom surface, a bevel surface 3431, a top surface 3432, a vertical surface, and two side surfaces 3433. The bottom surface is fixed to the cutting tooth support 342. The two side surfaces 3433 are disposed opposite to each other on the bottom surface. The bevel surface 3431 and the vertical surface are disposed opposite to each other on the bottom surface and are located between the two side surfaces 3433. The bevel surface 3431 is located on the bevel side facing the cutting tooth support 342. The top surface 3432 of the cutting tooth is positioned opposite to the bottom surface of the cutting tooth. The top surface 3432 of the cutting tooth connects the inclined surface 3431 of the cutting tooth, the vertical surface of the cutting tooth, and the two side surfaces 3433 of the cutting tooth. The bottom surface of the cutting tooth, the inclined surface 3431 of the cutting tooth, the top surface 3432 of the cutting tooth, the vertical surface of the cutting tooth, and the two side surfaces 3433 of the cutting tooth form a closed solid. The cutting teeth 343 are spaced 2 to 4 cm apart. The included angle between the inclined surface 3431 of the cutting tooth and the bottom surface of the cutting tooth is 25°-35°. The top surface 3432 of the cutting tooth includes an arc-shaped surface.

[0038] Specifically, this application conducts a simulation study on the influence of the number and spacing of the tooth cutters 34, as shown in Table 3 below.

[0039] Table 3 Simulation test of the number of tooth cutters

[0040] As shown in the table above, the load on the 3-tooth cutter is too high, and the wear is relatively severe, which seriously affects the service life of the equipment. On the other hand, the blade spacing of the 11-tooth cutter is too small, and the wear is relatively severe, resulting in high power consumption. Therefore, the tooth cutter with 5 to 9 teeth can be set according to different excavation conditions.

[0041] This application conducts a simulation study on the effect of the tilt angle of the tooth cutter 34, as shown in Table 4 below.

[0042] Table 4. Simulation Test of Tooth Cutter Angle

[0043] As shown in the table above, regarding the tilt angle of the toothed cutter 34, simulation tests were conducted at five angles: 20°, 25°, 30°, 35°, and 40°. The wear rate and service life showed a trend of first increasing and then decreasing. Considering all factors, 25°~35° is the preferred angle.

[0044] This application conducts a simulation study on the influence of the shape of the top surface 3432 of the cutter tooth 343, as shown in Table 5 below.

[0045] Table 5 Simulation Test of Cutter Tooth Top Surface Shape

[0046] As shown in the table above, simulation tests were conducted on three types of cutting edge top surface shapes: flat head, pointed head, and arc. The results show that the arc shape has higher wear resistance and lower soil adhesion rate, thus improving excavation efficiency and service life.

[0047] This application conducts a simulation study on the influence of the size of the cutting teeth 343 of the cutting cutter 34, as shown in Table 6 below.

[0048] Table 6. Simulation Test of Tooth Cutter Dimensions

[0049] As shown in the table above, the simulation experiment was conducted using five different combinations of cutting teeth 343 with different length and width. The results show that within the combination range of 60-80mm width and 100-120mm cutting length, both the cutting rate and wear can achieve good results.

[0050] Specifically, the toothed cutter 34 is made of cemented carbide, with a spacing of 3cm between adjacent teeth 343. Each tooth 343 is inclined outward, meaning the inclination angle of the tooth bevel 3431 is 30°. Each toothed cutter 34 has 5 teeth 343 at its front end, and the top surface 3432 of the teeth is an arc-shaped surface to improve wear resistance.

[0051] Preferably, the advance cutter 31 includes an advance cutter holder 311 detachably connected to the end face of the central post 32 and a plurality of advance cutter plates 312. The plurality of advance cutter plates 312 are radially fixed on the advance cutter holder 311, and the center of the assembly of the plurality of advance cutter plates 312 is higher than the surrounding area.

[0052] Specifically, in this embodiment, the advance cutter 31 consists of four advance cutter plates 312 arranged in a cross shape. Each advance cutter plate 312 is a right-angled triangle with seven blades on its hypotenuse. The blade angle of each blade is 55°, and the four advance cutter plates 312 form a pointed tip at their joint. The advance cutter plates 312 are made of cemented carbide and are used to pre-break hard strata to reduce stress concentration.

[0053] Preferably, the end face of the central column 32 is a concave spherical surface, and the side of the advance tool holder 311 facing the central column 32 is a convex spherical surface, with the convex spherical surface of the advance tool holder 311 engaging with the concave spherical surface of the central column 32. This structure eliminates installation gaps and improves load-bearing capacity. Furthermore, the advance tool holder 311 is provided with a positioning boss that engages with the positioning groove of the central column 32 to achieve rapid positioning and torque transmission.

[0054] Specifically, this application uses the finite element method to simulate the loess strata, with a cutter head diameter of 3m and a rotation speed of 5rpm. Simulation tests were conducted on no advance cutter (reference), single-row advance cutter, and double-row advance cutter, as detailed in Table 7 below.

[0055] Table 7 Simulation Test of Leading Tool Pattern

[0056] The table above shows that the results indicate that, compared with no leading edge, the maximum stress is reduced by 46% with double-row leading edge cutting, and the load fluctuation is effectively reduced.

[0057] This application further conducts simulation tests on the influence of the number of single-row cutting edges of the leading tool, as shown in Table 8 below.

[0058] Table 8 Simulation Test of the Number of Leading Blades

[0059] As shown in the table above, the 7-cutter scheme has the best overall efficiency and more even load distribution. Compared with the 5-cutter scheme, it reduces energy consumption by 15.5% and increases tunneling speed by 25%. The 5-cutter scheme has concentrated load, which leads to increased local wear. The 9-cutter scheme has too small a blade spacing, which causes muck blockage and reduces flow velocity by 12%, thus increasing energy consumption.

[0060] This application further conducts simulation tests on the influence of the cutting edge angle of the first tool, as shown in Table 9 below.

[0061] Table 9 Simulation Test of Leading Tool Cutting Edge Angle

[0062] As shown in the table above, when using LS-DYNA explicit dynamic simulation to test the cutting edge angle of the advance tool, although a cutting edge angle of 45°-50° saves effort, the cutting edge is prone to chipping, resulting in a shorter lifespan and greater wear. The specific energy consumption of a cutting edge angle of 55° is 19% lower than that of a cutting edge angle of 60°, the peak force is reduced by 15%, and the lifespan is longer. Therefore, a cutting edge angle of 55° is preferred.

[0063] Preferably, the drive system includes: a drive shaft 41, a central gear 42, and at least two sets of drivers. Each driver includes a drive gear 43 and a motor 44 that drives the drive gear 43 to rotate. The drive shaft 41 is rotatably connected inside the machine body 1 and coaxially connected to the central column 32. The central gear 42 is coaxially fixed on the drive shaft 41. The drive gears 43 of the at least two sets of drivers are arranged around the central gear 42 and externally meshed. The angle between the axis of the drive gear 43 and the axis of the drive shaft 41 is 12°~18°. If the axis of the drive gear 43 is parallel to the axis of the drive shaft 41, a symmetrical alternating load is easily formed on the cutterhead 3. When tunneling through uneven formations, the cutterhead 3 is prone to swaying, shaking, and abnormal noise. This application arranges the drive gears 43 at a certain angle, which can make the force on the cutterhead 3 more uniform, suppressing swaying and vibration, dispersing the load on the drive shaft 41, and making the force on the drive shaft 41 more gentle, thereby greatly improving the reliability and service life.

[0064] Specifically, the motor 44 is a geared motor with a single-unit power greater than 160kW. In this embodiment, two sets of drivers are provided, and the drive gears 43 of the two sets of drivers are arranged at an included angle of 15° on both sides of the drive shaft 41. The drive structure of this application can avoid the formation of a fixed symmetrical alternating load on the cutterhead. When tunneling in loess layers with uneven hardness and large load fluctuations, it can optimize torque distribution, effectively suppress cutterhead sway, vibration and abnormal noise, and make the overall force on the cutterhead more uniform and the operation more stable. At the same time, the drive load is no longer concentrated in the axial direction, but is distributed and evenly carried along the circumference of the drive shaft 41, which significantly reduces the local stress and eccentric wear of the drive shaft 41 and greatly improves the service life of the drive shaft 41.

[0065] Specifically, the machine body 1 is cylindrical, and slings are installed on the machine body 1 for hoisting the entire machine. A central hole is opened at the front end of the machine body 1, through which the drive shaft 41 passes and connects to the central column 32. A sealing system is installed between the drive shaft 41 and the central hole for sealing. The sealing system, extending from the outside into the machine body 1, includes: a labyrinth seal, a wear-resistant ring, an elastic seal, and an oil seal. The labyrinth seal consists of a wear-resistant cast iron scraper ring and an axially zigzag labyrinth. The wear-resistant ring is composed of a tungsten carbide hard alloy wear-resistant ring and a disc spring; the tungsten carbide hard alloy wear-resistant ring provides a long-term stable friction surface by forming a friction pair. The elastic seal uses a fluororubber multi-lip elastic seal, specifically an integrated three-lip skeleton seal equipped with a prestressed spring. The oil seal uses a hydrogenated nitrile rubber skeleton oil seal with spiral sealing patterns. Through a four-stage progressive composite sealing structure, the system achieves overall coarse filtration protection, main pressure bearing, leak prevention, and redundant isolation in a step-by-step manner, resulting in more reliable sealing and a longer service life for the equipment; it is suitable for excavation conditions in waterless and highly abrasive original soil.

[0066] Specifically, the soil chamber 2 is ring-shaped and is coaxially mounted on the front end of the machine body 1 via a slewing bearing. Multiple elliptical holes are opened on the front panel of the soil chamber 2, with a major axis of 60mm and a minor axis of 35mm, in order to increase the opening ratio and maximize the strength while improving the soil discharge efficiency.

[0067] Specifically, ten retaining plates 21 are evenly arranged circumferentially inside the soil chamber 2. The length of the retaining plate 21 is equal to the width of the annular groove inside the soil chamber 2. One end of the retaining plate 21 is hinged to the inner wall of the soil chamber 2. A hydraulic cylinder is installed between the lower surface of the retaining plate 21 and the inner wall of the soil chamber 2. The hydraulic cylinder drives the retaining plate 21 to swing, thereby realizing automatic adjustment of the angle of the retaining plate 21. The soil discharge system adopts a conveyor belt. One end of the conveyor belt is located in the inner circle of the soil chamber 2 and above the central column 32. The other end passes through the front end of the machine body 1 and extends to the rear end of the machine body 1. The cutter head 3 rotates and cuts the loess layer to form original slag. The slag enters the soil chamber 2 through the gaps between the spokes 33 and the elliptical holes on the soil chamber 2. As the cutter head 3 rotates, the soil bin 2 scrapes up the loose slag entering the soil bin 2 and carries it upwards. When the slag is rotated to the high area at the top of the soil bin 2, it falls freely due to gravity and falls precisely into the feed inlet of the conveyor belt below. The conveyor belt transports the received, unprocessed, and unhydrauliced ​​slag to the tail end of the machine body 1 in a low-energy, continuous manner, thus maintaining the natural state of the slag and directly transporting it for recycling.

[0068] The retaining plate 21 is adjusted according to the rotational speed of the cutter head 3. When the cutter head 3 is cutting at a low speed of less than 1.5 rpm, the retaining plate 21 maintains an inclination angle of 30°~35° to enhance soil carrying capacity; when the cutter head 3 is cutting at a high speed of more than 1.5 rpm, the retaining plate 21 maintains an inclination angle of 28°~32° to optimize the soil throwing trajectory. This is because at low speeds, the centrifugal force of the excavated soil is small and its natural fluidity is poor. If the inclination angle is too small, the excavated soil is prone to not being carried up, falling back and accumulating, and the discharge of excavated soil will be delayed. A larger inclination angle can increase the contact area between the retaining plate 21 and the excavated soil, improve the excavated soil carrying height and stability, and ensure that the excavated soil can be reliably carried up and enter the conveyor belt, avoiding the accumulation of excavated soil in the soil bin and blockage due to insufficient excavated soil carrying. At high speeds, the centrifugal force increases, and the excavated soil is prone to being thrown out prematurely, the landing point is deviated, and it cannot fall accurately into the conveyor belt. Adjusting the tilt angle allows control over the timing and angle of the excavated soil discharge, ensuring it falls stably into the center of the conveyor belt along an optimal parabolic trajectory. This prevents spillage, leakage, and impact on the conveyor belt edges, achieving a high degree of matching with the belt width, position, and conveying speed. The tilt angle of the retaining plate 21 is adjusted via a hydraulic cylinder, allowing for dynamic balance between low-speed, high-force and high-speed, precise operation. This truly adapts to the full range of working conditions required for waterless operations and direct discharge of untreated excavated soil, ensuring continuous, stable, and efficient slag removal.

[0069] Specifically, this application conducts simulation tests on the influence of the retaining plate inclination angle, as shown in Tables 10 and 11 below.

[0070] Table 10 Simulation test of retaining plate angle under high-speed working conditions (taking 1.8 rpm as an example)

[0071] Table 11 Simulation test of retaining plate angle under low-speed working conditions (taking 1.2 rpm as an example)

[0072] As shown in the table above, under both working conditions, the soil removal performance is better when the retaining plate angle is in the range of 25° to 40°. The retaining plate angle requirement is slightly larger under low-speed working conditions and slightly smaller under high-speed working conditions.

[0073] Specifically, it also includes a monitoring system. The monitoring system includes a laser target and a theodolite, which monitor direction through the laser target and the electronic theodolite. Eight hydraulic cylinders, each with a 45° circumference (the central angle between adjacent cylinders is 45°), are arranged in four groups of two-cylinder linkages (each group consists of two cylinders symmetrically positioned at 180°). The cylinders are double-acting stepped cylinders (with displacement sensors), each with a diameter of 120mm, a maximum stroke of 300mm, a maximum thrust of 1600kN, and a maximum hydraulic pressure of 31.5MPa. Under electrical and hydraulic control (e.g., a Siemens S7-1500 PLC), based on the real-time feedback of line deviation data from the laser target (installed in the machine body 1) and a high-precision electronic theodolite (such as a Leica TS60) outside the tunnel, the cylinders actuate to correct the direction. The correction accuracy is controlled within the range of 0.1°-0.2° / m, achieving precise correction of the tunneling direction and attitude control of the tunneling machine.

[0074] Specifically, it also includes a control system. The control system enables wireless signal transmission, visual monitoring, and integrated computer control, and is equipped with a high-definition camera and a laser rangefinder. The integrated computer console for integrated computer control enables wireless signal transmission through a wireless network module, receiving real-time operating condition images and data collected by displacement sensors, hydraulic pressure sensors, high-definition cameras, and laser rangefinders, and performing visual monitoring and operation.

[0075] This application is applicable to loess layers without groundwater, enabling fully dry, waterless operations under groundwater-free conditions. Conventional earth pressure balance tunneling machines and hydraulic pressure balance tunneling machines must treat the dry loess; otherwise, due to the extremely light and dust-prone nature of dry loess, it will cause rapid erosion, leading to the rapid wear and failure of seals, bearings, cutterheads, and other components.

[0076] This application utilizes a three-dimensional conical low-resistance cutterhead, a centrally located advance cutter for pre-crushing, high-aperture guide spokes to ensure smooth soil discharge, adjustable retaining plates with adjustable inclination angles based on rotational speed, and direct discharge of unprocessed excavated soil. The unprocessed excavated soil, after being cut by the cutterhead, can flow smoothly into the soil chamber directly through the cutterhead openings without watering, modification, or compaction. It is then stably carried and precisely thrown by the retaining plates onto the conveyor belt for continuous discharge. The entire process achieves dry, pressureless, continuous, and smooth excavated soil transportation and discharge, generating no waste mud or solidified waste. Because no mud treatment facilities are required, a multi-well tandem construction mode can be adopted. Each working well can independently discharge soil and advance, or excavate in parallel and collaboratively, making construction more flexible. This application significantly improves equipment reliability, construction efficiency, environmental friendliness, and overall economic benefits in long-distance waterless loess tunnel excavation, and is particularly suitable for long-distance tunnel projects. The excavated soil retains its natural gradation and original structure, and can be 100% directly recycled for on-site backfilling and resource utilization. This eliminates the need for soil improvement, mud preparation, mud-water separation, and excavated soil treatment processes and equipment required by traditional tunneling machines, significantly reducing construction electricity consumption, material consumption, and excavated soil transportation and disposal costs. It simplifies the construction process, improves tunneling continuity and construction efficiency, and achieves a significant reduction in comprehensive construction costs from multiple aspects such as equipment operation, energy consumption, excavated soil treatment, and recycling.

[0077] The tunnel excavator based on the original muck soil excavation method described in this application has been applied in two projects and has achieved excellent economic benefits.

[0078] Project 1: Project Name: Qianxian Auto Parts Industrial Park (High-speed Rail New City) Sewage Treatment Plant and Pipeline Supporting Project and Drainage and Flood Control Facilities Construction Project and Phase II.

[0079] Construction technology: Excavation and jacking of original excavated soil using a tunneling machine.

[0080] Construction pipes: 800 / 1000 / 1200 / 1350 / 1500 / 2000 / 2200 / 2400 / 2600 / 2800 / 3000mm.

[0081] Project volume: L=13000m.

[0082] Geological exploration summary: Loess layer without groundwater, loess layer + lyosite and paleosol.

[0083] Through actual operation experiments, it was found that without taking external resistance reduction or relay protection measures, a successful case was achieved in which a single section of 3000*2500*300mm reinforced concrete pipe with a self-weight of 20t was excavated to a length of 230m (230 / 2.5*20t=1840t).

[0084] Project 2: Project Name: Section 5 of the Water Distribution Project of the Ziwu Water Plant of the Shaanxi Hanjiang-to-Weihe River Water Diversion Project.

[0085] Construction technology: Excavation and jacking of original excavated soil using a tunneling machine.

[0086] Construction pipe material: DN2020*24mm steel pipe.

[0087] Work volume: L=1200m.

[0088] Geological exploration summary: Loess layer and paleosol without groundwater.

[0089] Through actual operation experiments, it was found that without taking external resistance reduction or relay protection measures, a successful case of single-ended tunneling of DN2020*24mm steel pipe with a single section of 6 meters and a self-weight of 7.5t was achieved for L=270m (270 / 6*7.5t=338t).

[0090] The following is an overview of the construction cost savings in Project 2. A comparison is made of the costs of excavation and jacking operations using a raw material tunneling machine versus a slurry & earth pressure tunneling machine.

[0091] The following will refer to slurry balance mechanical excavation and jacking construction as slurry excavation and jacking; earth pressure balance mechanical excavation and jacking construction as earth pressure excavation and jacking; and original muck excavation and jacking construction as original muck excavation and jacking.

[0092] 1. Water used in tunneling and jacking processes The water consumption ratio for slurry excavation and jacking construction is 1:5. The water consumption ratio for earth pressure tunneling and jacking construction is 1:1. The water consumption ratio for excavation and jacking of excavated waste soil is 1:0. Comprehensive market water price: 20 yuan / m³ 2 This includes: water fees, vehicle costs, labor costs, time costs, and traffic safety.

[0093] 1.1. Water costs for slurry excavation and jacking construction of 2000*24mm steel pipes 2000*24mm steel pipe, φ2080mm in the tunnel, L=2000m; construction water usage: 16.98m³. 3 / m*2000m≈33960m 3 The total cost was 679,200 yuan.

[0094] 1.2. Water costs for earth pressure excavation and jacking construction using 2000*24mm steel pipes. 2000*24mm steel pipe, φ2080mm in the tunnel, L=2000m; construction water usage: 3.396m³. 3 / m*2000m≈6792m 3The total cost was 135,800 yuan.

[0095] 1.3. Water costs for slurry excavation and jacking construction of 2000*24m steel pipe 2000*24mm steel pipe, φ2080mm in the tunnel, L=2000m; zero water consumption and zero cost.

[0096] 2. Treatment of mud and slag during excavation and jacking construction The form of excavated soil generated during slurry excavation and jacking construction: mud (1+5=6) (domestic mud separators cannot separate and recycle collapsible loess of type II and III in the Guanzhong region); The form of excavated soil generated during earth pressure tunneling and jacking operations is: mud (looseness coefficient not considered). The cost for transporting mud off-site is 150 yuan / m³. 3 ; The area of ​​the mud pit, the volume of excavated earthwork, the surrounding area, and the subsequent restoration costs (compensation for recultivation if the mud cannot be completely cleaned up); based on the minimum mud transportation price of 60 yuan / m³ for large-scale projects in Xi'an. 3 calculate; The excavated and jacking construction of the original soil is in its original state and can be recycled.

[0097] 2.1. 2000*24mm steel pipe slurry excavation and jacking construction 2000*24mm steel pipe, φ2080mm in the tunnel, L=2000m; the volume of mud generated during construction is 20.38m³. 3 / m*2000m≈40760m 3 The total cost was 2,445,600 yuan.

[0098] 2.2.2 2000*24mm steel pipe earth pressure excavation and jacking construction 2000*24mm steel pipe, φ2080mm in the tunnel, L=2000m; the amount of mud and sludge generated during construction is 3.4m³. 3 / m*2000m≈6800m 3 The total cost was 1.02 million yuan.

[0099] 2.3. 2000*24mm steel pipe in-situ excavation and jacking construction 2000*24mm steel pipe, φ2080mm in the tunnel, L=2000m; the construction produces untreated excavated soil, which can be used for filling in the Ziwu Water Plant at zero cost.

[0100] 3. Power supply for tunneling and jacking operations The slurry excavation and jacking construction process is calculated based on an excavation advance of 1m / h; Earth pressure tunneling and jacking construction are calculated based on a tunneling advance rate of 0.5 m / h. The original excavation and jacking process is calculated based on an excavation advance of 1m / h. A generator meeting the China III emission standard consumes 8L of fuel per 100kW*h. Based on the current fuel price of ¥8 / L and a power generation rate of 70% of generator power, the price is mainly determined by the following two factors: Generator rental fees (usage fee + wear and tear); Generator fuel consumption (tunneling efficiency and construction cycle).

[0101] 3.1. 2000*24mm steel pipe slurry excavation and jacking construction The construction power consumption is 60 + 37 + 100 = 197 / 0.7 ≈ 281 kW (using a 300 kW generator), and the cost is 300 / 100 * 8 * 8 * 2000 m ≈ 384,000 yuan.

[0102] 3.2.2000*24mm steel pipe earth pressure excavation and jacking construction The construction power consumption is 88+37+22=147 / 0.7≈210kw (using a 250kW generator), and the cost is 250 / 100*8*8*2*2000m≈640,000 yuan.

[0103] 3.3.2000*24mm steel pipe in-situ excavation and jacking construction The construction power consumption is 60 + 37 = 97 / 0.7 ≈ 138 kW (using a 200 kW generator), and the cost is 200 / 100 * 8 * 8 * 2000 m ≈ 256,000 yuan.

[0104] 4. Comprehensive Explanation of Cost Savings In summary, the cost analysis and comparison statistics of the three tunneling methods are shown in Table 12 below.

[0105] Table 12 Cost Comparison of Three Tunneling Methods

[0106] As shown in the table above, without considering the cost of construction site occupation and the earth pressure balance construction period, the cost savings per meter of in-situ excavation compared to slurry and earth pressure is: Original excavation and soil excavation vs. slurry saving: 3.2528 million yuan ÷ 2000 meters = 1626.4 yuan / meter; Original excavation vs. earth pressure saving: 1,539,800 yuan ÷ 2,000 meters = 769.9 yuan / meter.

[0107] Therefore, the tunnel excavator based on the original muck soil of this application can greatly save construction costs.

[0108] Example 2 This embodiment describes the tunneling process using the tunneling machine of Embodiment 1, and includes the following steps: S1. When the power is turned on, the drive motor rotates, thereby driving the system to control the cutter head to rotate continuously at a low speed of 1~3 rpm. The cutter head efficiently cuts the loess in contact with it to form loose original slag. S2. The excavated soil enters the soil bin through the opening of the cutter head. The soil bin is lifted up by the rotation of the cutter head. When the retaining plate reaches a certain height, the excavated soil is freed from the retaining plate at the high position and falls onto the conveyor belt of the soil discharge system. S3. The conveyor belt of the soil discharge system continuously transports the excavated soil to the tail of the tunneling machine at a preset speed, and the excavated soil falls into the soil hopper attached to the battery trailer. S4. After the slag hopper is full, it is transported to the starting well by a battery-powered vehicle. The slag hopper is then lifted out of the well opening and dumped into the slag storage point, where it can be directly backfilled and reused later. S5. The empty muck bucket is hoisted back to the bottom of the well and transported back by the battery-powered vehicle for repeated dumping. The tunneling process using a tunnel boring machine with original muck as disclosed in this application can realize tunneling operations and muck disposal, thereby significantly reducing the overall construction cost.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tunnel boring machine using pre-existing muck and excavated soil, characterized in that, include: The machine body (1), soil chamber (2), cutter head (3), drive system and soil discharge system; the soil chamber (2) is rotatably connected to the front end of the machine body (1), the cutter head (3) is set at the front end of the soil chamber (2), the drive system and soil discharge system are located inside the machine body (1), and the soil discharge system discharges the soil in the soil chamber (2); The cutter head (3) includes: a leading cutter (31), a central column (32) and multiple spokes (33). The central column (32) is coaxial with the soil chamber (2). The driving system drives the central column (32) to rotate. The multiple spokes (33) are arranged around the outer periphery of the central column (32). One end of the spoke (33) is fixed on the central column (32), and the other end is inclined towards the soil chamber (2) and fixed on the soil chamber (2). Multiple toothed blades (34) for scraping soil are provided on the spokes (33). The leading cutter (31) is fixed at the front end of the central column (32).

2. The tunnel boring machine based on original excavated soil as described in claim 1, characterized in that, The spokes (33) are located on the edges of the regular pyramid.

3. The tunnel boring machine based on original excavated soil as described in claim 2, characterized in that, The opening ratio of the cutter head (3) is 70% to 80%.

4. A tunnel boring machine based on any one of claims 1-3, characterized in that, Multiple toothed cutters (34) are arranged alternately on the spokes (33) to form two rows of toothed cutters (34).

5. A tunnel boring machine based on pre-existing muck and soil excavation as described in claim 4, characterized in that, The toothed cutter (34) includes: a toothed cutter mounting part (341), a toothed cutter support part (342), and a plurality of cutter teeth (343). The toothed cutter mounting part (341) is detachably connected to the spoke (33). The toothed cutter support part (342) is wedge-shaped and gradually shrinks from one end connected to the toothed cutter mounting part (341) to the end away from the toothed cutter mounting part (341). The plurality of cutter teeth (343) are spaced apart at the end of the toothed cutter support part (342) away from the toothed cutter mounting part (341).

6. A tunnel boring machine based on pre-existing muck and soil excavation as described in claim 5, characterized in that, The cutting tooth (343) includes: a bottom surface, a bevel surface (3431), a top surface (3432), a vertical surface, and two side surfaces (3433). The bottom surface is fixed on the tooth support (342). The two side surfaces (3433) are positioned opposite each other on the bottom surface. The bevel surface (3431) and the vertical surface are positioned opposite each other on the bottom surface and located between the two side surfaces (3433). The bevel surface (3431) is located on the bevel side facing the tooth support (342). The top surface (3432) of the tooth is arranged opposite to the bottom surface of the tooth. The top surface (3432) of the tooth connects the inclined surface (3431), the vertical surface of the tooth, and the two side surfaces (3433) of the tooth. The bottom surface, the inclined surface (3431), the top surface (3432), the vertical surface of the tooth, and the two side surfaces (3433) of the tooth form a closed solid. The teeth (343) are arranged at intervals of 2 to 4 cm. The angle between the inclined surface (3431) of the tooth and the bottom surface of the tooth is 25°-35°. The top surface (3432) of the tooth includes an arc-shaped surface.

7. A tunnel boring machine based on original excavated soil as described in claim 1, characterized in that, The advance cutter (31) includes an advance cutter holder (311) detachably connected to the end face of the central column (32) and a plurality of advance cutter plates (312). The plurality of advance cutter plates (312) are fixedly mounted radially on the advance cutter holder (311) with respect to the center of the advance cutter holder (311), and the center of the assembly of the plurality of advance cutter plates (312) is higher than the surrounding area.

8. A tunnel boring machine based on original excavated soil as described in claim 7, characterized in that, The end face of the central column (32) is a concave spherical surface, and the side of the advance tool holder (311) facing the central column (32) is a convex spherical surface. The convex spherical surface of the advance tool holder (311) is matched with the concave spherical surface of the central column (32).

9. A tunnel boring machine based on pre-existing muck and soil excavation as described in claim 1, characterized in that, The drive system includes a drive shaft (41), a central gear (42), and at least two sets of drivers. Each driver includes a drive gear (43) and a motor (44) that drives the drive gear (43) to rotate. The drive shaft (41) is rotatably connected inside the body (1). The drive shaft (41) is coaxially connected to the central column (32). The central gear (42) is coaxially fixed on the drive shaft (41). The drive gears (43) of at least two sets of drivers are arranged around the central gear (42) and mesh externally. The angle between the axis of the drive gear (43) and the axis of the drive shaft (41) is 12°~18°.

10. A tunneling process using a tunnel boring machine based on any one of claims 1 to 9, characterized in that, Includes the following steps: S1. The drive system controls the cutter head to rotate continuously at a low speed of 1~3 rpm, and the cutter head efficiently cuts the loess in contact with it to form loose original slag soil. S2. The excavated soil enters the soil chamber through the opening of the cutterhead, and the soil chamber transports the excavated soil to the soil discharge system as the cutterhead rotates. S3. The soil discharge system continuously transports the excavated soil to the tail of the tunneling machine at a preset speed, and the excavated soil falls into the soil hopper attached to the battery trailer. S4. After the slag bucket is full, it is transported to the starting well by a battery-powered vehicle, and the slag bucket is lifted out of the well opening and dumped to the slag storage point using hoisting equipment. S5. Empty slag hoppers are hoisted back to the bottom of the well by battery-powered trucks, which then transport the slag back for repeated dumping.

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