A combined cutter head, a rectangular pipe jacking machine and a using method thereof

Abstract

The present invention discloses a combined cutter head, a rectangular pipe jacking machine and a using method thereof. The combined cutter head is detachably connected by a plurality of central cutter head units into any rectangular cross-section. The central cutter head unit includes a central panel with a square orthographic projection outer contour and a central constant-pressure cutter head with a circular orthographic projection. A through hole for accommodating the central constant-pressure cutter head is provided at the center of the central panel. Four types of rock-breaking units are respectively arranged in the four corner areas of the central panel. A sensor array for detecting the formation type parameters corresponding to the four corner areas is provided on the central panel. The formation type parameters are input into a feature fusion model to obtain the formation type. The central cutter head unit starts the corresponding rock-breaking unit combination according to the formation type to perform coupled rock-breaking on the cutting blind area outside the central constant-pressure cutter head; the rectangular pipe jacking machine includes the combined cutter head. The technical solution provided by the present invention improves the tunneling efficiency and safety, and is applicable to pipe jacking operations of various formations and various extra-large cross-section rectangular pipe jacking machines.

Description

Technical Field

[0001] The invention relates to the technical field of cutter discs for pipe jacking machines, and in particular to a combined cutter disc, a rectangular pipe jacking machine and a use method thereof. Background Art

[0002] In the development of urban underground space, rectangular pipe jacking machines can directly excavate rectangular tunnels, which can minimize the impact on surrounding buildings and traffic. The current industry defines rectangular pipe jacking machines with a width of more than 10 meters or a height of more than 10 meters as super-large-section rectangular pipe jacking machines. Therefore, super-large-section rectangular pipe jacking machines have become important equipment for subway station excavation. The design of its core component, the cutterhead, directly affects the excavation efficiency and safety. In the existing technology, the cutterhead is mainly divided into two types: disc type and drum type.

[0003] 1. Technical status and defects of disc cutter

[0004] The disc cutterhead uses a single or multiple circular cutterheads to rotate and cut the tunnel face. For rectangular sections, if a single disc cutterhead is used, due to the mismatch of geometric shapes, large blind areas are formed in the four corners, and the blind area rate can reach 20%-30%. Existing solutions include:

[0005] 1. Arrangement of small cutter discs in blind areas: Small, independent disc cutter discs are additionally installed at the four corners of the rectangular sealing partition. Although the blind areas can be covered, the number of cutter discs is increased, the drive system is complex, and numerous drive systems will occupy a large space inside the shield. In addition, it is difficult to coordinate the control of the small cutter discs at the four corners with the main cutter disc in the center, which is prone to cutting overlap or missed blind areas. For example, a combined rectangular pipe jacking machine disclosed in the utility model patent with the authorization announcement date of 2018.07.13 and the authorization announcement number of CN 207609423 U has a cutter disc device including a central cutter disc and four small cutter discs respectively fixed on a fixed plate and having circular outer circumferences. The center of the central cutter disc is set on the central axis of the shell along the excavation direction, and the four small cutter discs are set at the four corners of the rectangular opening. This technical solution not only has a large number of cutter discs, but also has both cutting overlap and missed blind areas between the small cutter disc and the central cutter disc. If it is applied to a super-large cross-section rectangular pipe jacking machine, either more small cutter discs need to be arranged or more cutting overlaps need to be designed.

[0006] 2. Overlapping cutter discs in the front and back directions: Multiple groups of circular cutter discs are arranged in overlapping order in the front and back directions in an attempt to cover the entire cross-section, but this results in an increase in the overall thickness of the cutter discs, up to 1.5m-2m, which will not only aggravate the disturbance of the formation, but also cause a sudden increase in cutting resistance in the overlapping area, a low proportion of effective cutting contact area, and a tool wear rate of more than 30%. For example, a variable-section pipe jacking machine disclosed in an invention patent application with an application publication date of 2021.04.02 and application publication number of CN 112593955 A includes an intermediate module, a peripheral module, and a main module. The main module and the intermediate module form a stable module group, and a number of peripheral modules surround the periphery of the module group. The main module, the intermediate module, and the peripheral module are respectively provided with overlapping cutter discs in the front and back directions, and the cutter discs on the intermediate module and the peripheral module are eccentric cutter discs, making the overall structure more complicated.

[0007] 2. Technical status and defects of drum cutter disc

[0008] For example, in the drum-type rectangular tunnel boring machine disclosed in the utility model patent with the authorization announcement date of 2015.11.25 and the authorization announcement number of CN204804853U, the drum-type cutterhead cuts the tunnel face by rotating the drums parallel to each other, and its axis is perpendicular to the tunnel axis. Although there is no front and rear overlapping area, the following problems are more prominent:

[0009] 1. Insufficient geometric adaptability leads to cutting blind spots: In order to cover the super-large rectangular section, multiple groups of rollers need to be densely arranged along the height direction. Limited by the mechanical installation accuracy and drive structure, the distance between the edges of adjacent rollers must be ≥20cm, resulting in a lateral blind spot between the rollers. The cumulative gap between the rollers will exceed 1m; at the same time, if the diameter of the roller is small, a large number of rollers need to be arranged. If the diameter of the roller is large, the penetration of the roller into the tunnel face will be too large, which will aggravate the formation disturbance.

[0010] 2. Low cutting efficiency: The cutters on the drum surface are distributed in a spiral pattern, and the density of cutting contact points is only 50-80 / ㎡, while hard rock formations require ≥120 / ㎡ for effective crushing, resulting in slow excavation speed, only 0.5m / h in soft soil formations and as low as 0.2m / h in hard rock formations. Therefore, the tool life on the drum surface is short, and it is impossible to achieve normal pressure tool change during the jacking process. The cutters are only arranged on the drum surface, and when replaced, they need to be disassembled as a whole or enter a small space for operation. The maintenance cost is much higher than that of the full-section cutter head. The long maintenance cycle during construction leads to an extension of the construction cycle.

[0011] 3. The effective cutting contact area accounts for a very low proportion: The cutting track of a single roller is an annular area. For a 10m×10m section, if the roller diameter is 4m and the axial length is 10m, the single-side cutting area is only 2πRL=125.6m 2, R = 2m, L = 10m, and the cross-sectional area is 100 m², that is, the actual cutting coverage area of a single rotation of a single drum is about larger than the tunnel cross-sectional area. At the same time, multiple drums are required, and limited by the gaps between multiple adjacent drums, the proportion of the actual effective cutting contact area is low, resulting in a low cutting frequency and a long retention time of muck.

[0012] 4. Insufficient soil mixing and low muck discharge efficiency: The cutting trajectory of the drum-type cutterhead is a circular motion parallel to the axis, and its ability to mix the soil on the working face is weaker than that of the full-face rotating cutterhead, especially near the blind area: the soil in the gap and corner areas is not broken, and it is easy to form large pieces of muck to block the muck discharge port; in soft soil strata, the uncut soil and the cut soil are not evenly mixed, resulting in an increase in frictional resistance during jacking and an increase in the difficulty of axis control. The eccentric load effect is significant: the lateral water and soil pressure distribution of the rectangular cross-section pipe jacking machine is uneven, and the pressure on both sides is higher than that on the top and bottom. Among the drums arranged along the width direction of the drum-type cutterhead, the middle drum bears a relatively large axial thrust.

[0013] Therefore, the invention patent application with the publication date of April 12, 2024 and the publication number of CN 117868863 A discloses a rectangular pipe jacking machine with swing excavation and its construction method, which adopts a swing excavation device in the form of a toothed cutter drum. Although it solves the problem of the excavation blind area, it not only has a complex structure and motion, but also has a low excavation efficiency, and has almost no supporting effect on the working face, and is only applicable to the excavation of hard rock strata.

[0014] In summary, the combined cutterheads in the prior art face the following core challenges: Poor geometric adaptability: The circular cutterhead does not match the boundary of the rectangular working face, and there are lateral gaps in the drum-type cutterhead, resulting in the treatment of the blind area relying on "mechanical superposition", with a complex structure and difficult coordinated control, which is likely to cause formation disturbance; Discontinuous cutting coverage: The layout methods of overlapping circular cutterheads or dense drum cutterheads not only make it difficult to achieve blind area-free coverage of the full-section cutting trajectory, but also the proportion of the effective cutting contact area is extremely low; Limited formation adaptability: Poor formation adaptability. For the tunneling blind areas in different strata such as soft soil, hard rock, and composite strata, the existing solutions cannot achieve differential cutting, resulting in serious tool wear. The tool life in hard rock strata is only 80 - 100 hours, leading to high maintenance costs and long construction periods. That is, for super-large cross-section rectangular pipe jacking machines, the combined cutterheads in the prior art will lead to poor working face stability, low construction efficiency, and high safety risks. The core problems lie in the natural contradiction between "block cutting" and "full-section support", and the contradictory requirements of "improving construction efficiency" and "simplifying the structure".

[0015] It should be particularly noted that the above technical information is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or an indication in any form that the above technical information constitutes the prior art known to those skilled in the art. Summary of the Invention

[0016] Aiming at the deficiencies in the above background technology, the present invention proposes a combined cutterhead, a rectangular pipe jacking machine and its usage method. The technical problem to be solved is: how to improve the convenience of cutterhead combination for tunnels with different strata and different rectangular cross-sections, and at the same time achieve efficient tunneling and reduce the disturbance to the surrounding soil mass.

[0017] The technical solution of the present invention is as follows:

[0018] A combined cutterhead is detachably connected by a number of central cutterhead units into any rectangular cross-section. The central cutterhead unit includes a central panel with a square orthographic projection outer contour and a central normal pressure cutterhead with a circular orthographic projection. A through hole for accommodating the central normal pressure cutterhead is provided at the center of the central panel. Four types of rock-breaking units are arranged in the four corner areas of the central panel: a high-pressure water jet unit, a pulsed laser emission unit, a microwave radiation unit, and an abrasive air jet unit. A sensor array for detecting the formation type parameters corresponding to the four corner areas is provided on the central panel. The formation type parameters are input into a trained feature fusion model to obtain the formation type. Between adjacent central cutterhead units, corresponding rock-breaking unit combinations are activated according to the formation type to perform coupled rock-breaking on the cutting blind area outside the central normal pressure cutterhead. The mapping relationship between the formation type and the rock-breaking unit combination is: hard rock formation - pulsed laser emission unit and high-pressure water jet unit, soft rock formation - microwave radiation unit and abrasive air jet unit, fractured rock formation - high-pressure water jet unit and abrasive air jet unit, mixed formation - cyclic switching of the four types of rock-breaking units.

[0019] Based on the above technical solution, as a preferred technical solution of the combined cutterhead, an edge cutterhead unit is connected to the periphery of the central cutterhead unit. The edge cutterhead unit includes an edge panel with a square orthographic projection outer contour and an edge normal pressure cutterhead with a circular orthographic projection. A through hole for accommodating the edge normal pressure cutterhead is provided at the center of the edge panel. The four types of rock-breaking units and the sensor array located outside the projection of the edge normal pressure cutterhead are arranged in the four corner areas of the edge panel. The edge cutterhead unit activates the rock-breaking unit combination according to the formation type to perform coupled rock-breaking on the cutting blind area at the edge.

[0020] Based on the above technical solution, as a preferred technical solution of the combined cutterhead, the emission ends of the four types of rock-breaking units are respectively connected to the central panel or the edge panel through a servo mechanism with adjustable angles.

[0021] Based on the above technical solution, as a preferred technical solution of the combined cutterhead, the servo mechanism includes a biaxial servo motor that drives the rotational freedom and pitch freedom of the emission end support.

[0022] On the basis of the above technical solutions, as an optimized technical solution of the combined cutterhead, the sensor array includes several groups of detection units respectively located on the four sides of the central panel and the edge panel, and at least two groups of detection units are provided on each side of the central panel and the edge panel.

[0023] On the basis of the above technical solutions, as an optimized technical solution of the combined cutterhead, each group of detection units includes a pressure sensor for measuring the reaction force of the working face during rock breaking, an ultrasonic transducer for measuring the longitudinal wave and transverse wave transmission speeds, a spectrometer probe for measuring the quartz content, and an accelerometer for measuring the vibration frequency.

[0024] On the basis of the above technical solutions, as an optimized technical solution of the combined cutterhead, the side lengths of the central panel and the edge panel are equal, and the diameters of the central normal pressure cutterhead and the edge normal pressure cutterhead are equal.

[0025] On the basis of the above technical solutions, as an optimized technical solution of the combined cutterhead, when the rock-breaking unit combination performs coupled rock breaking on the cutting blind area, it includes spatial coupling for controlling the three-dimensional cross jet of the emission end to cover the blind area, and also includes timing coupling for controlling the sequential startup of different rock-breaking units.

[0026] A rectangular pipe jacking machine includes the combined cutterhead described in any one of the above technical solutions. The adjacent central cutterhead units, adjacent edge cutterhead units, adjacent central cutterhead units and edge cutterhead units, and between the edge panel and the outer shield are all detachably connected by bolt groups. The central panel and the edge panel are both detachably connected to the rear sealing partition through the supporting structures on the back. The medium channels and wire harnesses of various rock-breaking units are all built in the supporting structures.

[0027] A method for using a rectangular pipe jacking machine uses the rectangular pipe jacking machine described in the above technical solutions. According to the cross-sectional size of the rectangular tunnel to be excavated, the corresponding number of central cutterhead units and edge cutterhead units are assembled into a suitable combined cutterhead for jacking operation.

[0028] Compared with the prior art, the combined cutterhead, rectangular pipe jacking machine and its using method proposed by the present invention adopt the principles of prior action, substitution of mechanical systems, extraction, reverse operation, prior counteraction, change of physical state, local quality, and equipotential. It can not only adaptively couple rock breaking for the blind areas of different strata, but also be conveniently assembled into different rectangular cross-sections, avoiding various drawbacks of using multiple layers of circular cutterheads to cover the entire face, especially problems such as a large number of cutterheads, complex structure, large overall thickness of the cutterhead, large and uneven cutting resistance, ground disturbance, difficulty in using an atmospheric pressure cutterhead for tool replacement when using a stacked structure of multiple layers of circular cutterheads. It also avoids various drawbacks of using a drum-type cutterhead to adapt to a rectangular cross-section, especially problems such as a large number of required drums, excessive penetration into the face, low proportion of effective cutting contact area, low cutting efficiency, difficulty in tool replacement, significant eccentric load effect, and low slag discharge efficiency. At the same time, in this application, the water after water jet rock breaking by the high-pressure water jet unit can improve the muck, thereby improving the slag discharge efficiency. The present invention not only simplifies the overall structure of the combined cutterhead, but also has strong geometric adaptability, can cover all blind areas, improves the convenience of cutterhead combination for different strata and different rectangular cross-sections. All cutterheads adopt circular atmospheric pressure cutterheads, with a high proportion of effective cutting contact area, high cutting efficiency and convenient tool replacement, reducing the downtime, improving the tunneling efficiency, and at the same time reducing the disturbance to the surrounding soil mass, and is particularly suitable for pipe jacking operations of large-section and extra-large-section rectangular pipe jacking machines.

[0029] Meanwhile, in various combinations of rock breaking units of the present invention, coupling of rock breaking media, spatial coupling of rock breaking jets, and time sequence coupling of rock breaking are simultaneously adopted. For hard rock strata, the high-pressure water jet can not only expand the melting holes formed by pulsed laser ablation, but also the formed temperature gradient can further weaken the hard rock and cause it to automatically spall. For soft rock strata, abrasive air can not only expand the face softened by microwave, but also prevent the slag from sludging and blocking the slag chute. For fractured rock strata, the high-pressure water jet and abrasive air jet not only form a water knife and a wind knife acting on the face, but also can further stimulate the cavitation effect between them to cause the fractured rock to automatically spall. For mixed strata, the four types of rock breaking units cycle and switch, and the four rock breaking media act in rotation. The spatial coupling therein makes the direction of the high-pressure water jet form a three-dimensional intersection with the direction of pulsed laser emission, the direction of the abrasive air jet form a three-dimensional intersection with the direction of microwave radiation, and the direction of the abrasive air jet form a three-dimensional intersection with the direction of pulsed laser emission. The time sequence coupling therein means that while pulsed laser or microwave radiation ablates the blind area of the face, the face is also heated, and then the high-pressure water jet or abrasive air jet is used to expand the ablated face, and at the same time the high-pressure water jet or abrasive air jet causes the heated face to rapidly cool down.

[0030] Meanwhile, since the central atmospheric pressure cutter head is located in the through hole of the central panel and the edge atmospheric pressure cutter head is located in the through hole of the edge panel, the metal cutters of the atmospheric pressure cutter head are preferably embedded in the emission ends of the high-pressure water jet unit, pulsed laser emission unit, microwave radiation unit, and abrasive air jet unit within the central panel and the edge panel. Preferably, the radial coverage of the atmospheric pressure hob or atmospheric pressure ripping cutter or atmospheric pressure scraper at the edges of the central atmospheric pressure cutter head and the edge atmospheric pressure cutter head exceeds the corresponding through holes and is within the outer contour of the orthographic projection of the central panel. That is, the metal cutters and the respective jet units are arranged offset in both the axial and radial directions, and the metal cutters at the edges can radially cover the gap between the through hole and the cutter head panel. This not only avoids the negative impact of the metal cutters on the respective emission ends, but also allows the respective emission ends to be close to the tunnel face. At the same time, the sensor arrays on the central panel and the edge panel are radially away from the respective emission ends and axially protrude from the respective emission ends. Description of the Drawings

[0031] To more clearly illustrate the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0032] Figure 1 is the front view structural schematic diagram of the combined cutter head;

[0033] Figure 2 is Figure 1 the enlarged view of the central cutter head unit shown;

[0034] Figure 3 is Figure 1 the enlarged view of the edge cutter head unit shown.

[0035] Explanation of the Reference Numerals in the Drawings:

[0036] Central cutter head unit 1, central panel 1-1, central atmospheric pressure cutter head 1-2;

[0037] Edge cutter head unit 2, edge panel 2-1, edge atmospheric pressure cutter head 2-2;

[0038] High-pressure water jet unit 3;

[0039] Pulsed laser emission unit 4;

[0040] Microwave radiation unit 5;

[0041] Abrasive air jet unit 6;

[0042] Sensor array 7, pressure sensor 7-1, ultrasonic transducer 7-2, spectrometer probe 7-3, accelerometer 7-4;

[0043] Shield shell 8. Specific implementation mode

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the core concept of the present invention and the following embodiments, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0045] These embodiments are provided in this application to make this application thorough and complete, and to fully convey the scope of this application to those skilled in the art. It should be noted that: unless otherwise specifically stated, the relative arrangements of components and steps, the components of materials, numerical expressions and values described in these embodiments should be interpreted as merely exemplary, rather than as a limitation.

[0046] It should be noted that in the description of this application, unless otherwise stated, "several" means greater than or equal to two; the orientation or positional relationships indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", "axial", "radial", etc. are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation of this application. When the absolute position of the described object changes, the relative position relationship may also change accordingly.

[0047] In addition, the "first", "second" and similar terms used in this application do not indicate any order, quantity or importance, but are only used to distinguish different parts. "Vertical" is not strictly vertical, but within the allowable error range. "Parallel" is not strictly parallel, but within the allowable error range. The terms such as "including" or "comprising" mean that the elements before this term cover the elements listed after this term, and do not exclude the possibility of also covering other elements.

[0048] It should also be noted that in the description of this application, unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances. When it is described that a specific device is located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device.

[0049] All terms used in this application have the same meanings as understood by those of ordinary skill in the art to which this application pertains, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, such as those, should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense, unless specifically defined as such here.

[0050] Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and devices should be regarded as part of the specification.

[0051] A combined cutter head, as Figures 1 to 3 shown, can be detachably connected by a number of central cutter head units 1 into any rectangular cross-section. Each central cutter head unit 1 has the same structure, and the overall front view projection is a square. It can be connected by a bolt group into a rectangular cross-section of any size and shape. For example, when the side length of each central cutter head unit 1 is 2m, five central cutter head units 1 are arranged in both the longitudinal and transverse directions, then a 10m×10m cross-section can be formed; six central cutter head units 1 are arranged in the longitudinal direction and four central cutter head units 1 are arranged in the transverse direction, then a 12m×10m cross-section can be formed; five central cutter head units 1 are arranged in the longitudinal direction and six central cutter head units 1 are arranged in the transverse direction, then a 10m×12m cross-section can be formed. The side length of the central cutter head unit 1 can be designed according to specific requirements, such as 2.5m, 3m, etc. No matter how the side length of the central cutter head unit 1 is selected, the above assembly method can be adopted. It should be especially noted that each central cutter head unit 1 can also adopt different sizes, for example, including two types with side lengths of 2m and 4m respectively, or two types with side lengths of 2m and 3m, etc.

[0052] The central cutterhead unit 1 includes a central panel 1-1 with a square orthographic projection outer contour and a central constant-pressure cutterhead 1-2 with a circular orthographic projection. The diameter of the central constant-pressure cutterhead 1-2 is slightly smaller than the side length of the central panel 1-1. For example, when the side length of the central panel 1-1 is 2 m, the diameter of the central constant-pressure cutterhead 1-2 is 1.8 m; when the side length of the central panel 1-1 is 3 m, the diameter of the central constant-pressure cutterhead 1-2 is 2.8 m, and so on. A through hole for accommodating the central constant-pressure cutterhead 1-2 is provided at the center of the central panel 1-1. After the central constant-pressure cutterhead 1-2 is connected to the drive system on the sealing partition through the cutterhead drive flange, the outer periphery of the central constant-pressure cutterhead 1-2 is concentric with the through hole of the central panel 1-1 and has a clearance fit. At the same time, the metal cutters on the central constant-pressure cutterhead 1-2 axially protrude from the through hole to prevent the outer end face of the central constant-pressure cutterhead 1-2 from being too far from the outer end face of the central constant-pressure cutterhead 1-2. Preferably, the radial coverage range of the constant-pressure hob or constant-pressure tearing cutter or constant-pressure scraping cutter at the edge of the central constant-pressure cutterhead 1-2 exceeds the through hole and is within the orthographic projection outer contour of the central panel 1-1. At the same time, in order to facilitate the tool change operation of the central constant-pressure cutterhead 1-2, it is preferably designed that the side length of the central cutterhead unit 1 is 4 m or more.

[0053] Four types of rock-breaking units are respectively arranged in the four corner areas of the central panel 1-1: a high-pressure water jet unit 3, a pulsed laser emission unit 4, a microwave radiation unit 5, and an abrasive air jet unit 6. The high-pressure water jet unit 3, the pulsed laser emission unit 4, the microwave radiation unit 5, and the abrasive air jet unit 6 are all prior arts. Only a brief introduction related to the present technical solution is made in this embodiment, and the component composition and working principle thereof will not be elaborated.

[0054] The core component of the high-pressure water jet unit 3 is a high-pressure water nozzle for high-pressure water jet. Preferably, the aperture of the high-pressure water nozzle is 0.2 mm - 0.5 mm, and the high-pressure water jet pressure is 150 - 250 MPa. The hard rock is broken by using the water wedge effect, the cavitation effect, and the temperature gradient formed with the pulsed laser emission unit 4 and the microwave radiation unit 5.

[0055] The core component of the pulsed laser emission unit 4 is a fiber laser for emitting pulsed laser. Preferably, the power of the fiber laser is 10 kW - 20 kW, and the wavelength of the emitted pulsed laser is 1064 nm. The thermal crack induction is realized by using its heat energy exceeding 1500 °C. At the same time, a sharply changing temperature gradient is formed by acting with the high-pressure water jet unit 3 or the abrasive air jet unit 6, so as to realize the automatic spalling of part of the rock stratum.

[0056] The core component of the microwave radiation unit 5 is a spiral antenna for generating microwave radiation. Preferably, the operating frequency of the spiral antenna is 2.45 GHz, and its power is 30 kW - 50 kW. By utilizing its thermal effect, the mineral lattice is thermally expanded and broken, and at the same time, a rapidly changing temperature gradient is formed in cooperation with the high-pressure water jet unit 3 or the abrasive air jet unit 6, thereby realizing the automatic peeling of some rock formations.

[0057] The core components of the abrasive air jet unit 6 are a low-pressure abrasive air jet mixing device and an abrasive jet multi-stage acceleration device. For this embodiment, the core lies in the characteristics of the abrasive. Preferably, quartz sand with a particle size of 80 μm - 120 μm is used as the air abrasive. The quartz sand impacts and breaks the soft soil formation at high speed under the action of high-pressure air, or acts jointly with the high-pressure water jet unit 3 on the fractured rock formation.

[0058] Preferably, the high-pressure water jet unit 3 is arranged at the upper left corner of the central panel 1-1, the pulsed laser emission unit 4 is arranged at the upper right corner of the central panel 1-1, the microwave radiation unit 5 is arranged at the lower left corner of the central panel 1-1, and the abrasive air jet unit 6 is arranged at the lower right corner of the central panel 1-1. Then, between any two adjacent central cutter head units 1, there is a combination of rock-breaking units in the cutting blind area at their connection position. Between any four adjacent central cutter head units 1, there are multiple combinations of rock-breaking units in the cutting blind area at their connection position. Even for the central cutter head unit 1 located at the corners of the entire modular cutter head, there is at least one type of rock-breaking unit among the high-pressure water jet unit 3, the pulsed laser emission unit 4, the microwave radiation unit 5, and the abrasive air jet unit 6 at the right angle not adjacent to other central cutter head units 1.

[0059] A sensor array 7 for detecting the formation type parameters corresponding to the four corner areas is provided on the central panel 1-1. The formation type parameters are input into a trained feature fusion model to obtain the formation type. Preferably, the feature fusion model adopts the random forest algorithm. By inputting the formation type parameters detected by the sensor array 7, the formation type - hard rock / soft rock / fractured rock / mixed formation is output. Its training set contains more than 2000 groups of measured data of different formations, and the classification accuracy rate is ≥95%. Preferably, the surface of the sensor is covered with wear-resistant sapphire glass with a hardness of 9H, and an air curtain purging device is built in to remove rock powder interference in real time.

[0060] Between adjacent central cutterhead units 1, corresponding rock-breaking unit combinations are activated according to the formation type to perform coupled rock-breaking on the cutting blind areas outside the central atmospheric-pressure cutterhead 1-2. The mapping relationship between the formation type and the rock-breaking unit combinations is as follows: hard rock formation - pulsed laser emission unit 4 and high-pressure water jet unit 3; soft rock formation - microwave radiation unit 5 and abrasive air jet unit 6; fractured rock formation - high-pressure water jet unit 3 and abrasive air jet unit 6; mixed formation - cyclic switching of the four types of rock-breaking units. Preferably, the mixed formation is stratified by a thickness of 10 cm, and each layer is matched with a different rock-breaking unit combination.

[0061] Hard rock formation: First, pulsed laser melting holes last for 0.5 s, then high-pressure water jet cracking lasts for 1.5 s, and then temperature gradient spalling is formed to form a "point-line-plane" fragmentation path; Soft rock formation: Microwave heating lasts for 1 s to dehydrate and soften clay minerals, and then abrasive air jet lasts for 2 s for rapid peeling to avoid mud clogging, and then temperature gradient spalling is formed to form a "point-line-plane" fragmentation path; Fractured rock formation: High-pressure water jet penetrates along the fracture for 1 s, and then abrasive air jet pulses and sweeps for 0.5 s to expand the fracture surface by using the wedge cracking effect and cavitation effect.

[0062] It should be noted that the proportion of the blind areas at the four corners of the entire combined cutterhead in the entire cross-section is extremely low. Moreover, there is at least one type of the above-mentioned rock-breaking units in this blind area. Therefore, compared with using traditional metal cutters to break rock in the blind area, not only is the tunneling efficiency significantly improved, ensuring the efficient completion of the construction progress, but also the disturbance to the surrounding soil is reduced, ensuring the safety of the construction.

[0063] On the basis of the above embodiments, as a preferred embodiment of the combined cutterhead, an edge cutterhead unit 2 is connected to the periphery of the central cutterhead unit 1. The edge cutterhead unit 2 includes an edge panel 2-1 with a square orthographic projection outer contour and an edge atmospheric-pressure cutterhead 2-2 with a circular orthographic projection. A through hole for accommodating the edge atmospheric-pressure cutterhead 2-2 is provided at the center of the edge panel 2-1. The four corner regions of the edge panel 2-1 are each arranged with the four types of rock-breaking units and the sensor array 7 outside the projection of the edge atmospheric-pressure cutterhead 2-2. The edge cutterhead unit 2 activates the rock-breaking unit combination according to the formation type to perform coupled rock-breaking on the cutting blind areas at the edge.

[0064] That is, the basic structure of the edge cutter head unit 2 provided in this embodiment is the same as that of the central cutter head unit 1. The difference is that in the four corner areas of the central panel 1-1 of the central cutter head unit 1, one type of rock-breaking unit is provided at each corner, while in the four corner areas of the edge panel 2-1 of the edge cutter head unit 2, four types of rock-breaking units are provided at each corner. Therefore, when the edge cutter head unit 2 is arranged on the periphery of the central cutter head unit 1, the edge cutter head unit 2 can not only form any combination of rock-breaking units at the four corners of the entire combined cutter head, but also form any combination of rock-breaking units with the adjacent central cutter head unit 1. It can also form a redundant design between adjacent edge cutter head units 2 and between adjacent edge cutter head units 2 and the central cutter head unit 1. When some rock-breaking units fail, it can be replaced without stopping the machine.

[0065] This embodiment provides two types of cutter head units. One is the central cutter head unit 1 used in the above embodiment, which is used to assemble the middle area of the entire combined cutter head; the other is the edge cutter head unit 2 provided in this embodiment, which is used to assemble on the periphery of the central cutter head unit 1. For example, when the contour dimensions of the central cutter head unit 1 and the edge cutter head unit 2 are the same and the side length is 2m, and the cross-section of the combined cutter head to be assembled is 8m×12m, then 8 central cutter head units 1 are spliced in the middle area, and 16 edge cutter head units 2 are spliced on its periphery; of course, other implementation methods can also be selected. For example, 6 edge cutter head units 2 are respectively used on both sides of the entire combined cutter head, and central cutter head units 1 are used in other positions; it is also possible to use only 4 edge cutter head units 2 at the four corners of the entire combined cutter head, and central cutter head units 1 are used in other positions. In addition, the central cutter head unit 1 and the edge cutter head unit 2 can be alternately used on the periphery of the entire combined cutter head.

[0066] In order to enable those skilled in the art to better implement the technical solution of the present invention, the slag discharge structure and slag discharge method of the present invention are now described in principle. Principle 1: Modular adaptation, that is, each central cutter head unit 1 and each edge cutter head unit 2 are provided with independent slag discharge ports. That is, the same as the prior art, slag discharge ports are provided on the central atmospheric pressure cutter head 1-2 and the edge atmospheric pressure cutter head 2. Slag discharge ports corresponding to each cutter head are provided on the sealing partition of the rectangular pipe jacking machine. The adjacent slag discharge ports are respectively interconnected through corresponding screw conveyors at the outlet of the screw conveyors through flexible coupling interfaces, forming a three-level structure of primary slag discharge at the slag discharge port - summary at the coupling interface - external discharge of the main slag discharge system. Principle 2: Dynamic collaborative control: The screw conveyors at each position are linked in real time with the central atmospheric pressure cutter head 1-2, the edge atmospheric pressure cutter head 2-2 and each rock-breaking unit. When jet rock-breaking and metal tool rock-breaking are carried out, the slag discharge in the corresponding area is started synchronously to avoid the accumulation of slag materials affecting the rock-breaking efficiency.

[0067] It should be noted that since technical features such as the slag discharge port, screw conveyor, dynamic cooperative control method, and main slag discharge system are existing technologies themselves, in order to avoid a long and cumbersome description that fails to highlight the core content, only the above-mentioned principle description related to the overall technical solution is provided in this embodiment, and the specific content of existing technologies such as the slag discharge port, screw conveyor, and dynamic cooperative control method themselves will not be elaborated further.

[0068] Based on the above embodiment, as a preferred embodiment of the combined cutterhead, the emission ends of the four types of rock-breaking units are respectively connected to the central panel 1-1 or the edge panel 2-1 in an angle-adjustable manner through servo mechanisms. That is, this embodiment provides an emission end with adjustable angle, enabling the rock-breaking units on the central panel 1-1 and the edge panel 2-1 to carry out coupling effects more efficiently. According to the change of formation types, more diverse and targeted jet path couplings can be provided, which can make the three-dimensional cross-coverage paths of spatial couplings more diverse, and also make the sequence of the successive action areas of temporal couplings more diverse.

[0069] For example, for the same cutting blind area between four adjacent central cutterhead units 1, the high-pressure water jet unit 3, pulsed laser emission unit 4, microwave radiation unit 5, and abrasive air jet unit 6 all act on the cutting blind area directly in front of them simultaneously. Then, the emission ends of the high-pressure water jet unit 3, pulsed laser emission unit 4, microwave radiation unit 5, and abrasive air jet unit 6 adjust their angles simultaneously to act on other areas, that is, the orientations of the high-pressure water jet unit 3 and the pulsed laser emission unit 4 are swapped, and the orientations of the microwave radiation unit 5 and the abrasive air jet unit 6 are swapped.

[0070] Based on the above embodiment, as a preferred embodiment of the combined cutterhead, the servo mechanism includes a two-axis servo motor that drives the rotational freedom and pitching freedom of the emission end support, thereby enabling flexible adjustment of the orientation of the emission end and covering the entire cutting blind area.

[0071] Based on the above embodiment, as a preferred embodiment of the combined cutterhead, the sensor array 7 includes several groups of detection units located on the four sides of the central panel 1-1 and the edge panel 2-1 respectively, and at least two groups of detection units are provided on each side of the central panel 1-1 and the edge panel 2-1.

[0072] Preferably, each group of detection units includes a pressure sensor 7-1 for measuring the reaction force of the tunnel face during rock breaking, an ultrasonic transducer 7-2 for measuring the longitudinal wave and transverse wave transmission velocities, a spectrometer probe 7-3 for measuring the quartz content, and an accelerometer 7-4 for measuring the vibration frequency. Then the formation type parameters include the pressure value F, the longitudinal wave velocity Vp, the transverse wave velocity Vs, the quartz content Q, and the main vibration frequency f. When F > 80 MPa, Vp > 4000 m / s, and Q > 50%, the rock breaking unit combination for hard rock formations is activated, the power of the optical pulse laser emission unit 4 is adjusted to 15 kW, the laser focal length is 100 mm, the pressure of the high-pressure water jet unit 3 is adjusted to 200 MPa, and the water jet frequency is 50 Hz.

[0073] When F < 30 MPa, Vp < 2000 m / s, and Q < 20%, the rock breaking unit combination for soft rock formations is activated, the power of the microwave radiation unit 5 is adjusted to 40 kW, the microwave heating temperature is 600 °C, and the abrasive air jet unit 6 uses 100-μm quartz sand for high-pressure pulsed jetting.

[0074] When Vs / Vp < 0.5 and the vibration amplitude > 3g, the rock breaking unit combination for fractured rock formations is activated, the pressure of the high-pressure water jet unit 3 is adjusted to 150 MPa, the water jet frequency is 50 Hz, the water jet angle is 45° with respect to the tunnel face, and the purge interval of the abrasive air jet unit 6 is 1 s.

[0075] Preferably, the pressure sensor 7-1 has a diameter of 10 mm and is installed in an embedded structure, flush with the surface of the central panel 1-1 or the edge panel 2-1; the ultrasonic transducer 7-2 includes a transmitting end and a receiving end, with a spacing of 50 mm and is tilted 15° towards the tunnel face; the spectrometer probe 7-3 has a field of view angle of 30° and is 10 cm - 20 cm away from the tunnel face; the accelerometer 7-4 is rigidly fixed inside the central panel 1-1 or the edge panel 2-1, 5 cm away from the edge.

[0076] On the basis of the above embodiments, as a preferred embodiment of the combined cutter head, the side lengths of the central panel 1-1 and the edge panel 2-1 are equal, and the diameters of the central atmospheric pressure cutter head 1-2 and the edge atmospheric pressure cutter head 2-2 are equal. Preferably, both the central atmospheric pressure cutter head 1-2 and the edge atmospheric pressure cutter head 2-2 are provided with atmospheric pressure hob cutters, atmospheric pressure ripping cutters, atmospheric pressure scraping cutters, and central atmospheric pressure cutters for forward overexcavation.

[0077] On the basis of the above embodiments, as a preferred embodiment of the combined cutter head, when the rock breaking unit combination performs coupled rock breaking on the cutting blind area, it includes spatial coupling for controlling the three-dimensional cross jet of the emission end to cover the blind area, and also includes timing coupling for controlling the sequential startup of different rock breaking units.

[0078] A rectangular pipe jacking machine includes the combined cutter head described in any of the above embodiments. Between adjacent central cutter head units 1, between adjacent edge cutter head units 2, between adjacent central cutter head units 1 and edge cutter head units 2, and between the edge panel 2-1 and the outer peripheral shield 8 are detachably connected by bolt groups. The central panel 1-1 and the edge panel 2-1 are both detachably connected to the rear sealing partition through the support structures on the back. The medium channels and wire harnesses of various rock-breaking units are all built in the support structures.

[0079] A method for using a rectangular pipe jacking machine uses the rectangular pipe jacking machine described in the above embodiments. According to the cross-sectional size of the rectangular tunnel to be excavated, the corresponding number of central cutter head units 1 and edge cutter head units 2 are assembled into a suitable combined cutter head for jacking operation.

[0080] The details not elaborated in the present invention are all well-known conventional technical means in the art.

[0081] The above content shows and describes the basic principles, main features and beneficial effects of the present invention. The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A combined cutter head, characterized in that: Several central cutter head units are detachably connected to form an arbitrary rectangular cross-section. The central cutter head unit includes a central panel with a square orthographic projection outline and a central normal-pressure cutter head with a circular orthographic projection. A through hole for accommodating the central normal-pressure cutter head is provided at the center of the central panel. Four types of rock-breaking units are arranged in the four corner areas of the central panel: a high-pressure water jet unit, a pulsed laser emission unit, a microwave radiation unit, and an abrasive air jet unit. One type of rock-breaking unit is arranged at each corner. A sensor array for detecting the formation type parameters corresponding to the four corner areas is provided on the central panel. The formation type parameters are input into a trained feature fusion model to obtain the formation type. Adjacent central cutter head units start the corresponding rock-breaking unit combination according to the formation type to perform coupled rock-breaking on the cutting blind area outside the central normal-pressure cutter head. The mapping relationship between the formation type and the rock-breaking unit combination is as follows: hard rock formation - pulsed laser emission unit and high-pressure water jet unit; soft rock formation - microwave radiation unit and abrasive air jet unit; fractured rock formation - high-pressure water jet unit and abrasive air jet unit; mixed formation - the four types of rock-breaking units are cycled and switched; An edge cutter head unit is connected to the periphery of the central cutter head unit. The edge cutter head unit includes an edge panel with a square orthographic projection outline and an edge normal-pressure cutter head with a circular orthographic projection. A through hole for accommodating the edge normal-pressure cutter head is provided at the center of the edge panel. The four corner areas of the edge panel each have one of the four types of rock-breaking units and the sensor array located outside the projection of the edge normal-pressure cutter head. The edge cutter head unit starts the rock-breaking unit combination according to the formation type to perform coupled rock-breaking on the cutting blind area at the edge.

2. The combined cutter head according to claim 1, wherein: The emission ends of the four types of rock-breaking units are respectively connected to the central panel or the edge panel at an adjustable angle through a servo mechanism.

3. The modular cutter head according to claim 2, wherein: The servo mechanism includes a biaxial servo motor that drives the rotational freedom and pitching freedom of the emission end support.

4. The modular cutter head according to claim 2 or 3, characterized in that: The sensor array includes several groups of detection units respectively located on the four sides of the central panel and the edge panel. At least two groups of detection units are provided on each side of the central panel and the edge panel.

5. The modular cutter head according to claim 4, wherein: Each group of detection units includes a pressure sensor for measuring the reaction force of the tunnel face during rock-breaking, an ultrasonic transducer for measuring the longitudinal wave and transverse wave transmission speeds, a spectrometer probe for measuring the quartz content, and an accelerometer for measuring the vibration frequency.

6. The modular cutter head according to claim 5, wherein: The side lengths of the central panel and the edge panel are equal, and the diameters of the central normal-pressure cutter head and the edge normal-pressure cutter head are equal.

7. The modular cutter head according to any one of claims 1-3, 5-6, characterized in that: When the rock-breaking unit combination performs coupled rock-breaking on the cutting blind area, it includes spatial coupling to control the three-dimensional cross-jet of the emission ends to cover the blind area, and also includes timing coupling to control the sequential start of different rock-breaking units.

8. A rectangular pipe jacking machine, characterized in that: Including the combined cutter head described in claim 7, adjacent central cutter head units, adjacent edge cutter head units, adjacent central cutter head units and edge cutter head units, and between the edge panel and the peripheral shield are all detachably connected by a bolt group. The central panel and the edge panel are both detachably connected to the rear sealing partition through the support structure on the back. The medium channels and wire harnesses of various rock-breaking units are all built in the support structure.

9. A method for using a rectangular pipe jacking machine, characterized in that: Adopt the rectangular pipe jacking machine described in claim 8, and assemble the corresponding number of central cutter head units and edge cutter head units into a suitable combined cutter head according to the cross-sectional size of the rectangular tunnel to be excavated for jacking operation.

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