A rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operation

Abstract

The present invention discloses a rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operations, which includes a shield shell. At the front end of the shield shell, there are several independently retractable overexcavation support mechanisms. On the side, there is a spacing measurement device for measuring the distance from the close-fitting segment. On the left and right sides of the outside, composite rubber layers are respectively connected to form two independent and expandable sealing cavities. It also includes a lubricating mud pumping unit for forming a lubricating mud film, a pressure-regulating mud pumping unit for pumping or discharging mud into and out of the sealing cavity, and a reinforcing mortar pumping unit for pumping concrete mortar to the tail outside the shield shell. During the pipe jacking process, each overexcavation support mechanism sequentially overexcavates the formation space of the lubricating mud film, and the lubricating mud pumping unit pumps mud to form a lubricating mud film. When the detection result of the spacing measurement device is abnormal, the pressure-regulating mud pumping unit adjusts the pressure of the two sealing cavities, so that the shield shell returns to the target position under the reaction force of the sealing cavity.

Description

Technical Field

[0001] The invention relates to the technical field of a pipe jacking machine for double-hole double-line close-fitting pipe jacking operation, in particular to a rectangular pipe jacking machine for double-hole double-line close-fitting pipe jacking operation. Background Art

[0002] In the double-hole double-line small-spacing close-fitting pipe jacking operation, the surrounding soil is disturbed during the first single-hole jacking, which often causes uneven force during the second jacking process, resulting in partial outward deviation of the machine head. At the same time, in order to ensure the accuracy of the center line of the double-line tunnel, the machine head will be corrected in the direction of the completed segment of the first tunnel during the jacking process. In the case of double-control double-line extremely small-spacing close-fitting pipe jacking operation, the jacking machine cutter head is easy to touch and scratch the existing segment, causing damage to the jacking machine and the segment. Therefore, for the double-hole double-line extremely small-spacing close-fitting pipe jacking operation, it is more important to control the spacing between the two jacking tunnels within 100mm during construction, and the impact of the second jacking on the first tunnel.

[0003] After searching, it was found that the utility model patent with the authorization announcement date of 2019.12.13 and the authorization announcement number of CN 209780894 U was disclosed, which specifically disclosed a pipe jacking machine for double-hole double-line extremely small spacing pipe jacking operation, including a shield shell, the shield shell is provided with mud injection holes in the four directions of upper, lower, left and right, and the number of mud injection holes corresponding to each direction is greater than or equal to one, and the mud injection holes penetrate the shield shell; valves are provided corresponding to the mud injection holes, and the valves are fixed on the inner surface of the shield shell; and a soil and sand pump is provided inside the shield shell, and the soil and sand pump can be connected to the valve and inject mud to the outside of the shield shell through the corresponding mud injection holes. The technical solution is to set mud injection holes in four directions of the shield shell of the pipe jacking machine and inject mud to the outside of the pipe jacking machine through the soil and sand pump. Since the mud pumped out by the soil and sand pump is almost non-flowing, it has a good supporting effect, so that the direction of the pipe jacking machine can be corrected in time in the double-hole double-line extremely small spacing pipe jacking operation, avoiding the second jacking from causing damage to the first tunnel.

[0004] In the technical solution of the above utility model patent, it is precisely because the mud pumped out by the earth-sand pump is almost non-flowing, when the soil pressure on the outside is greater than the soil pressure on the inside between it and the first tunnel during the second jacking, the amount of mud pumped inward by the earth-sand pump is difficult to control, and the mud is difficult to recover once it is pumped out by the earth-sand pump, resulting in the difficulty in accurately controlling the spacing between the double holes and double lines, and thus deviating from the designed position, making it difficult to achieve ideal control accuracy; at the same time, since the mud pumped out to the periphery of the shield shell of the pipe jacking machine is almost non-flowing, the jacking resistance of the pipe jacking machine will increase, which will in turn aggravate the further disturbance of the surrounding soil. In addition, the disturbance of the surrounding soil by the first single-hole jacking will not only further affect the accuracy of the second jacking, but also in the case of shallow cover, large cross-section, and other box culverts or tunnels nearby, it will cause the surrounding soil to settle beyond the standard and affect the safety of construction.

[0005] However, the invention patent application with the application publication date of 2024.05.28 and the application publication number of CN 118088201 A discloses a method for correcting torsion of a rectangular pipe jacking tunnel, which includes the following steps: S1. Measure the torsion angle α of the tunnel; S2. Determine the model of the pipe jacking machine and the excavation route of the pipe jacking machine; S3. Excavate and clean the soil that hinders the rotation of the tunnel according to the excavation route; S4. When the pipe machine excavates to the ground wall of the receiving well, retreat the pipe, and inject retreat grouting slurry for filling during the withdrawal process; S5. Use mixed slurry to seal the starting well door; S6. Perform unbalanced grouting on the periphery of the rectangular tunnel, and use the torsion force generated by the grouting reaction force of the unbalanced grouting to push the tunnel to the designed posture, and then switch to balanced grouting and maintain pressure; S7. After the tunnel is straightened, use double liquid slurry to replace the retreat grouting slurry and the unbalanced grouting slurry.

[0006] In the technical solution of the above-mentioned invention patent application, although a fluid slurry is used to twist the pipe jacking machine, there are the following problems: first, it is only applicable to geologically hard or unevenly hard strata, while in geologically soft strata, if unbalanced grouting is performed on the periphery of the rectangular pipe jacking machine, the fluid slurry will escape to the outside of the target position, and then the torsional force generated by the grouting reaction force of the unbalanced grouting cannot be used to push the pipe jacking machine to rotate to the designed posture; at the same time, precisely because its technical solution is only applicable to geologically hard or unevenly hard strata, it is necessary to use a small-sized circular pipe jacking machine on the periphery of the rectangular pipe jacking machine. The machine excavates and cleans the soil that hinders the rotation of the tunnel from the starting well, and then performs a series of operations such as backward grouting, plugging, unbalanced grouting, balanced grouting and slurry replacement. Therefore, it is only suitable for single correction of large-size deviation of the jacking machine, and cannot achieve continuous correction; more importantly, due to the above-mentioned formation adaptability problems, especially the need to use a small-sized circular pipe jacking machine on the periphery of the rectangular pipe jacking machine for excavation and cleaning, it can be determined that due to formation limitations and space limitations, this technical solution cannot be applied to double-control double-line close-fitting pipe jacking operations, let alone double-control double-line close-fitting pipe jacking operations in relatively soft geological formations.

[0007] In summary, in the process of dual-control dual-line close-fitting pipe jacking operations in relatively soft formations, how to achieve precise control of the jacking direction and reduce the disturbance to the surrounding soil is a technical problem that needs to be solved urgently.

[0008] 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 admitting or implying in any form that the above technical information constitutes the prior art already known to those skilled in the art. Summary of the invention

[0009] In view of the deficiencies in the above-mentioned background art, the present invention provides a rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operations. The technical problem to be solved is: how to accurately control the jacking direction and reduce the disturbance to the surrounding soil during the double-control and double-line close-fitting pipe jacking operation in a relatively soft stratum.

[0010] The technical solution of the present invention is as follows:

[0011] A rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operations includes a shield shell, an excavation system and a grouting system. A number of independently retractable over-excavation support mechanisms are provided at the front end of the shield shell, a spacing measuring device for measuring the distance from the close-fitting segment is provided on the side, and composite rubber layers are respectively connected to the left and right outside to form two independent and expandable sealing cavities. The grouting system includes a lubricating mud pumping unit for pumping mud between the composite rubber layer and the tunnel inner wall to form a lubricating mud film, a pressure-regulating mud pumping unit for pumping or discharging mud into or from the two sealing cavities respectively, and a reinforcement mortar pumping unit for pumping concrete mortar to the tail outside the shield shell. During the jacking process, each over-excavation support mechanism sequentially over-excavates the formation space of the lubricating mud film outside the shield shell contour, and the lubricating mud pumping unit pumps mud into the formation space to form the lubricating mud film. When the detection result of the spacing measuring device is abnormal, the pressure-regulating mud pumping unit adjusts the pressure of the two sealing cavities, so that the shield shell returns to the target position under the reaction force of the sealing cavities.

[0012] The above technical solution is the core technical solution for achieving the invention purpose of this application. The most important thing is its inventive concept. The pressure of the independent and expandable sealed cavities is adjusted by the pressure-regulating mud pumping unit. Axial overexcavation, radial overexcavation and radial support are carried out by the overexcavation support mechanism to construct a space for forming a lubricating mud film and correcting deviation. The lubricating mud is pumped into the radial overexcavation area by the lubricating mud pumping unit to form a lubricating mud film. Furthermore, during the double-control and double-line close-fitting pipe jacking operation in a relatively soft stratum, precise control of the jacking direction is achieved. This not only avoids the problems of difficult control and large disturbance to the surrounding soil caused by pumping out almost non-flowing mud outside the shield to provide a deviation correction reaction force, but also avoids the problems that the deviation correction method of pumping out unbalanced slurry outside the shield cannot be applied to relatively soft strata, cannot correct deviation continuously, and is not applicable to the double-control and double-line close-fitting pipe jacking operation. The overexcavation support mechanism in it performs axial overexcavation on the shield, so that the face and the surrounding soil are isolated from each other in both the axial and radial directions and advanced support is carried out to reduce the soil disturbance caused by the cutter head system when excavating the face. At the same time, the space radially overexcavated by the overexcavation support mechanism outside the shield can be used for pumping in lubricating mud to form a lubricating mud film. The lubricating mud film can not only isolate the surrounding soil from the rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operation, but also provide a certain torsional space for the precise alignment of the rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operation, and can also reduce the jacking resistance of the rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operation. At the same time, it can wrap the composite rubber layer and extend the service life of the composite rubber layer. The sealed cavities are independent of each other, and the mud filled inside will not overflow into the surrounding soft soil. By controlling the mud filling amount of each sealed cavity respectively through the pressure-regulating mud pumping unit, different support reaction forces can be provided by the sealed cavities on both sides respectively, and the support reaction force is stable and reliable. The mud filling amount in each sealed cavity can also be dynamically adjusted through the pressure-regulating mud pumping unit, which not only avoids the problem that the flowing mud in the prior art cannot provide a reliable support reaction force, but also solves the problems that the flowing mud cannot be recovered and the non-flowing mud cannot be adjusted, that is, solves the problem of difficult precise control of the jacking direction and position in the double-control and double-line close-fitting pipe jacking operation caused by unstable support reaction force and inability to dynamically adjust.

[0013] It should be specifically noted that although the sealed cavity bulges out of the shield in the radial direction after grouting and expanding in the sealed cavity, the overexcavation support mechanism has carried out radial overexcavation in advance, and the lubricating mud pumping unit pumps the lubricating mud into the gap between the front end of the sealed cavity and the soil. Furthermore, not only the backfill space where the sealed cavity bulges out of the shield is eliminated, but also as the rectangular pipe jacking machine jacks forward, the mud between the front end of the sealed cavity and the soil will be squeezed between the outer surface of the composite rubber layer and the surrounding soil, and a mud film will be automatically formed.

[0014] On the basis of the above technical solution, as an optimized technical solution for a rectangular pipe jacking machine used in double-hole and double-line close-fitting pipe jacking operations, the composite rubber layer includes an inner aramid fiber reinforcement layer, a middle honeycomb polyurethane buffer layer, and an outer high-wear-resistant rubber matrix. Silicon carbide particles are embedded on the outer surface of the outer layer, and diversion grooves for guiding soil particles to be discharged backward are provided. The diversion grooves are arranged obliquely relative to the axial direction of the shield shell.

[0015] On the basis of the above technical solution, as an optimized technical solution for a rectangular pipe jacking machine used in double-hole and double-line close-fitting pipe jacking operations, a receiving groove for accommodating the composite rubber layer is provided on the outside of the shield shell. When the pressure-regulating mud pumping unit does not pump pressure-regulating mud into the sealed cavity, the outer surface of the composite rubber layer is flush with the outer surface of the shield shell.

[0016] On the basis of the above technical solution, as an optimized technical solution for a rectangular pipe jacking machine used in double-hole and double-line close-fitting pipe jacking operations, a deployable and foldable wavy fold structure is formed at the edge where the composite rubber layer is connected to the shield shell through a laser cutting process.

[0017] On the basis of the above technical solution, as an optimized technical solution for a rectangular pipe jacking machine used in double-hole and double-line close-fitting pipe jacking operations, a hardened alloy protection plate is provided on the shield shell outside the wavy fold structure, and a driving mechanism is provided inside the shield shell to drive the hardened alloy protection plate to extend out of the shield shell and cover the wavy fold structure obliquely or be received into the shield shell.

[0018] On the basis of the above technical solution, as an optimized technical solution for a rectangular pipe jacking machine used in double-hole and double-line close-fitting pipe jacking operations, composite rubber layers are also connected to the upper side and / or the lower side of the outside of the shield shell to form an independent and expandable sealed cavity.

[0019] On the basis of the above technical solution, as an optimized technical solution for a rectangular pipe jacking machine used in double-hole and double-line close-fitting pipe jacking operations, a plurality of independent sealed cavities are provided on each side of the outside of the shield shell. Each sealed cavity is strip-shaped and extends along the axial direction of the shield shell, and the sealed cavities are arranged at intervals in parallel.

[0020] On the basis of the above technical solution, as an optimized technical solution for a rectangular pipe jacking machine used in double-hole and double-line close-fitting pipe jacking operations, the overexcavation support mechanism includes a driving motor connected to a driving oil cylinder. The driving motor is connected to a milling head through a driving shaft, and the excavation contour of the milling head exceeds the outer contour of the shield shell by 10-20 mm.

[0021] On the basis of the above technical solution, as an optimal technical solution for a rectangular pipe jacking machine used in double-hole and double-line close-fitting pipe jacking operations, one end of the driving oil cylinder is connected to the shield, and the other end is connected to the driving motor through a sliding box body. The sliding box body is slidably matched with the shield. The driving motor and the driving shaft are both arranged in the sliding box body. The contour of the front end of the sliding box body extends 20-50 mm beyond the outer contour of the shield. A spiral blade for discharging over-excavated soil to the soil bin is arranged on the driving shaft.

[0022] On the basis of the above technical solution, as an optimal technical solution for a rectangular pipe jacking machine used in double-hole and double-line close-fitting pipe jacking operations, the mud pumping channel of the lubricating mud pumping unit is arranged on the shield at the position of the driving oil cylinder. The sealing cavity and the mud pumping channel of the sealing cavity are located on the shield behind the driving oil cylinder. The concrete mortar pumping channel of the reinforced mortar pumping unit passes through the shield tail seal brush.

[0023] Compared with the prior art, the rectangular pipe jacking machine proposed by the present invention for double-hole and double-line close-fitting pipe jacking operations avoids the problems of difficult control and large disturbance to the surrounding soil caused by pumping out almost non-flowing mud outside the shield to provide a deviation correction reaction force during the double-control and double-line close-fitting pipe jacking operation in a relatively soft stratum. It also avoids the problems that the deviation correction method of pumping out unbalanced slurry outside the shield cannot be applied to a relatively soft stratum, cannot continuously correct the deviation, and cannot be applied to double-control and double-line close-fitting pipe jacking operations. It realizes the precise control of the jacking direction and reduces the disturbance to the surrounding soil, and realizes the precise control and safe construction of double-control and double-line close-fitting pipe jacking operations in a relatively soft stratum with shallow overburden, large cross-section, and adjacent to other structures around.

[0024] Although the present invention uses mud with strong fluidity and relatively common in the prior art, it subversively utilizes the mud with strong fluidity to achieve the invention purpose, and adopts the following technical principles completely different from the prior art.

[0025] A. Merging technical principle: Merge the "radial over-excavation", "axial over-excavation" and "supporting effect" of the over-excavation support mechanism; merge the "over-excavation isolation effect", "supporting effect" and "formation space of lubricating mud film" of the over-excavation support mechanism; merge the "lubricating mud film formed by fluid mud" and the "adjustable-pressure and non-flowing sealing cavity filled with fluid mud"; merge the "pumping of lubricating mud film" and the "pressure regulation of the sealing cavity", all realized through mud pumping.

[0026] B. Principle of reverse operation technology: In "soft strata or soft formations that are not suitable for providing support reaction force through flowing slurry", "flowing slurry" is subversively adopted to form a lubricating mud film and adjust the support reaction force of the sealing cavity; the "excavation, backward grouting, plugging, unbalanced grouting, balanced grouting and slurry replacement" adopted in the existing technology in strata with uneven hardness is subversively designed as "directly grouting and regulating pressure into the sealing cavity"; the existing technology of "only pumping flowing slurry or non-flowing mud around the pipe jacking machine" is subversively designed as "pumping slurry into the sealing cavity or discharging slurry from the sealing cavity"; the existing technology of "minimizing the gap between the inner wall of the tunnel and the outer wall of the shield shell during pipe jacking operation and filling it with tail grouting" is subversively designed as "radially overexcavating through the overexcavation support mechanism, expanding its gap through the expansion of the sealing cavity, and then filling and reinforcing it through the reinforced mortar pumping unit"; in the construction environment with particularly large frictional resistance such as pipe jacking operation, the "outer wall of the composite rubber layer that is usually excluded in the existing technology" is subversively adopted, and the life of the composite rubber layer is extended through the lubricating mud film and the radial overexcavation of the overexcavation support mechanism; the existing technology is to "use a small-sized circular pipe jacking machine to excavate and clean the periphery of the rectangular pipe jacking machine" at the launching shaft of pipe jacking operation, and the present invention subversively "adopts the overexcavation support mechanism to continuously overexcavate following the front end of the shield shell"; it is generally believed that setting grooves on the outer surface of the composite rubber layer will increase the frictional resistance, but the present invention subversively sets inclined diversion grooves, and during the jacking process, the synergistic effect of the lubricating mud film and the diversion grooves forms a pattern of discharging the soil particle-slurry mixed fluidization.

[0027] C. Principle of pre-action technology: Axial overexcavation, radial overexcavation and isolation support are preformed through the overexcavation support mechanism to form an isolation support for reducing soil disturbance and a formation space for the lubricating mud film; a sealing cavity is pre-designed outside the shield shell to form a support reaction force that is dynamically adjustable at any time and will not randomly change its position and direction during the jacking process; a lubricating slurry pumping unit pumps lubricating slurry for forming a lubricating mud film in front of the sealing cavity to achieve friction reduction and extend the service life of the composite rubber layer. At the same time, the lubricating mud film can cooperate with the inclined diversion grooves, and the soil particles slide along the diversion grooves obliquely to the rear or left and right sides of the composite rubber layer.

[0028] D. Principle of dynamic technology: Several overexcavation support mechanisms can adaptively select the positions that need to be overexcavated according to the changes in the jacking conditions to excavate the lubricating slurry pumping space required for the lubricating mud film; according to the dynamic measurement results of the spacing measuring device, the pressure regulating pumping unit can pump slurry for pressure regulation into the corresponding sealing cavity in real time. At the same time, according to the changes in the jacking state, the pressure regulating pumping unit can also dynamically pump and drain the slurry in each sealing unit.

[0029] E. Principle of homogenization technology: The slurry pumped by the lubricating slurry pumping unit forms a lubricating mud film, a homogeneous mud film is formed to reduce friction on the shield shell and the composite rubber layer; the homogenized slurry is pumped into the sealing cavity by the pressure-regulating slurry pumping unit, and is used to form a sealing cavity that can provide a homogeneous support reaction force.

[0030] F. Principle of dimensionality elevation technology: In the prior art, grouting or mud injection is only carried out outside the shield of the pipe jacking machine. In the present invention, grouting is carried out outside the shield to form a lubricating mud film, grouting is also carried out in the sealing cavity to form a reaction force support structure, and the slurry in the sealing cavity is dynamically pumped out, achieving precise continuous dynamic control.

[0031] G. In summary, the present invention also adopts the technical principles of physical state change, intermediate medium, asymmetry, and local quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention, the drawings required for description in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0033] Figure 1 It is the front view of a rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operation;

[0034] Figure 2 It is Figure 1 the side view of the middle shield shell;

[0035] Figure 3 It is Figure 2 the enlarged view of the relative position relationship between the composite rubber layer and the hardened alloy protection plate in the middle;

[0036] Figure 4 It is the sectional view schematic diagram of the composite rubber layer;

[0037] Figure 5 It is the composition block diagram of the grouting system;

[0038] Figure 6 It is the partial sectional view of the shield shell and the segment;

[0039] Figure 7 It is Figure 6 the enlarged view of the A position in the middle;

[0040] Figure 8 It is Figure 6 the enlarged view of the B position in the middle;

[0041] Figure 9 It is the sectional view of the sliding box body;

[0042] Figure 10 It is a cross-sectional view when the sliding box body extends after being assembled with the outer box body.

[0043] Explanation of the reference numerals in the attached drawings:

[0044] Shield shell 1, accommodation groove 101, hardened alloy protection plate 102, shield tail sealing brush 103;

[0045] Grouting system 2, lubricating mud pumping unit 201, lubricating grouting hole 2011, pressure-regulating mud pumping unit 202, pressure-regulating grouting hole 2021, pressure-regulating slurry discharge hole 2022, reinforcement mortar pumping unit 203, mortar pumping pipeline 2031;

[0046] Over-excavation support mechanism 3, driving oil cylinder 301, driving motor 302, driving shaft 303, milling head 304, sliding box body 305, reducer 306, outer box body 307, spiral blade 308, slag outlet 309;

[0047] Spacing measuring device 4;

[0048] Composite rubber layer 5, aramid fiber reinforced layer 501, honeycomb polyurethane buffer layer 502, highly wear-resistant rubber matrix 503, diversion groove 504, wavy fold structure 505;

[0049] Sealing cavity 6;

[0050] Driving mechanism 7, rack 701. Specific implementation manners

[0051] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with 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 shall fall within the protection scope of the present invention.

[0052] These embodiments are provided by the present application to make the present application thorough and complete, and to fully convey the scope of the present application to those skilled in the art. It should be noted that: unless otherwise specifically stated, the relative arrangements of the components and steps, the components of the materials, the numerical expressions and numerical values described in these embodiments shall be construed as merely exemplary, rather than as limitations.

[0053] It should be noted that in the description of this application, unless otherwise specified, "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 therefore cannot be construed as a limitation on this application. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0054] In addition, the "first", "second" and similar terms used in this application do not denote 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. Terms such as "comprising" or "including" mean that the elements before this word cover the elements listed after this word, and do not exclude the possibility of also covering other elements.

[0055] It should also be noted that in the description of this application, unless otherwise clearly specified and limited, the terms "installed", "connected" and "coupled" 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. 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.

[0056] All terms used in this application have the same meanings as those understood by those of ordinary skill in the art to which this application belongs, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, such as, 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.

[0057] 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.

[0058] A rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operations, such as Figure 1 、 Figure 5As shown, it includes a shield shell 1, an excavation system and a grouting system 2. The slag discharge system in the excavation system and the shield shell 1 is the same as that in the prior art. The excavation system can be a combined cutterhead or a tunneling drum with cutting teeth, etc. The slag discharge system can be a screw conveyor and a belt conveyor, etc. Therefore, the present embodiment and the attached drawings of the specification will not be described in detail. As Figure 6 shown, during the pipe jacking operation, the already assembled segments and the jacking system behind the rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operation jack the shield shell 1. The excavation system at the front end of the shield shell 1 excavates the working face, and the excavated muck is discharged through the slag discharge system. At the same time, the grouting system 2 injects concrete mortar between the outer wall of the already assembled segments behind the rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operation and the inner wall of the tunnel excavated by the excavation system, and between the outer wall of the already assembled segments behind the rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operation and the outer wall of the other tunnel that has completed the pipe jacking operation.

[0059] As Figure 1 and Figure 6 shown, a number of independently retractable overexcavation support mechanisms 3 are provided at the front end of the shield shell 1. The excavation range of the overexcavation support mechanisms 3 exceeds the outer contour of the shield shell 1. Therefore, each overexcavation support mechanism 3 can not only excavate ahead along the pipe jacking direction, but also overexcavate radially outside the shield shell 1. As Figure 1 shown, each overexcavation support mechanism 3 can be arranged on the left side plate and the right side plate of the shield shell 1, or overexcavation structures 3 can be arranged on the top plate, the left side plate and the right side plate of the shield shell 1. Each overexcavation support mechanism 3 is arranged in parallel. The adjacent overexcavation support mechanisms 3 can be in close contact with each other or in clearance fit. Preferably, the clearance should be controlled within 100 mm.

[0060] As Figure 2 shown, a spacing measuring device 4 for measuring the distance from the close-fitting segment is provided on the side of the shield shell 1. The close-fitting segment is the outer wall of the other tunnel that has completed the pipe jacking operation. The spacing measuring device 4 can be a spacing measuring device based on visual principle, laser ranging principle, ultrasonic wave, radar, mechanical contact type, etc. Since its structure and action principle are both prior art, the present embodiment will not be described in detail. Those skilled in the art can select a suitable type for practical use.

[0061] As Figure 2 、 Figure 3 and Figure 6 shown, composite rubber layers 5 are respectively connected to the left and right sides outside the shield shell 1 to form independent and expandable sealing cavities 6, that is, the outer walls of the left side plate and the right side plate of the shield shell 1 are both connected with composite rubber layers 5, and the edge of the composite rubber layer 5 is sealed with the outer wall of the shield shell 1. Then, the composite rubber layer 5 and the outer wall of the shield shell 1 in the area covered by the composite rubber layer 5 enclose the sealing cavity 6.

[0062] As Figures 5 to 8 shown, the grouting system 2 further includes a lubricating mud pumping unit 201 for pumping mud between the composite rubber layer 5 and the inner wall of the tunnel to form a lubricating mud film, a pressure-regulating mud pumping unit 202 for pumping or discharging mud into or from the two sealing cavities 6 respectively, and a reinforcing mortar pumping unit 203 for pumping concrete mortar to the tail outside the shield 1. At least one pressure-regulating grouting hole 2021 and at least one pressure-regulating slurry discharge hole 2022 communicating with the sealing cavity 6 are provided on the shield 1. The grouting pump in the pressure-regulating mud pumping unit 202 is connected to the pressure-regulating grouting hole 2021 through a grouting pipeline, and the slurry discharge pump in the pressure-regulating mud pumping unit 202 is connected to the pressure-regulating slurry discharge hole 2022 through a slurry discharge pipeline.

[0063] Preferably, a mortar pumping pipeline 2031 connected to the reinforcing mortar pumping unit 203 is provided inside the shield 1, and corresponding electromagnetic directional control valves are provided on the mortar pumping pipeline 2031. Both the pressure-regulating grouting hole 2021 and the pressure-regulating slurry discharge hole 2022 are connected with electromagnetic directional control valves. A lubricating grouting hole 2011 is further provided on the shield 1, and the grouting pump of the lubricating mud pumping unit 201 is connected to the lubricating grouting hole 2011 through a grouting pipeline; preferably, a plurality of lubricating grouting holes 2011 are provided and arranged at intervals along the width direction of the composite rubber layer 5, so that the lubricating mud film formed by the mud discharged from the lubricating grouting holes 2011 corresponds to the composite rubber layer 5 front and back; further preferably, the arrangement positions of the respective overexcavation support mechanisms 3 correspond to the arrangement positions of the respective lubricating grouting holes 2011 front and back.

[0064] As for the specific constitution of the lubricating mud pumping unit 201, the pressure-regulating mud pumping unit 202, and the reinforcing mortar pumping unit 203, there can be various selections. For example, the lubricating mud pumping unit 201 and the pressure-regulating mud pumping unit 202 share a grouting pump, and the on-off of the corresponding grouting pipelines is controlled by a grouting pipeline and a reversing solenoid valve in a timely manner, while the reinforcing mortar pumping unit 203 uses an independent grouting pump and grouting pipeline; or the lubricating mud pumping unit 201, the pressure-regulating mud pumping unit 202, and the reinforcing mortar pumping unit 203 respectively use independent grouting pumps and grouting pipelines. Those skilled in the art can reasonably select the model of the grouting pump, the model of the grouting pipeline, its arrangement position, and the fixing method.

[0065] During the pipe jacking operation, each overexcavation support mechanism 3 sequentially overexcavates the formation space of the lubricating mud film outside the contour of the shield 1, and the lubricating mud pumping unit pumps mud into the formation space to form the lubricating mud film. When the detection result of the spacing measuring device 4 is abnormal, the pressure regulating mud pumping unit adjusts the pressure of the two sealing cavities 6, so that the shield 1 returns to the target position under the reaction force of the sealing cavities 6. The reinforced mortar pumping unit pumps concrete mortar to the tail of the shield 1 through the grouting pipeline, thereby filling the overexcavated space of the overexcavation support mechanism 3 and filling the space supported by the sealing cavities 6 after being filled with mud tightly.

[0066] The above embodiment is the core embodiment for realizing the invention purpose of the present application. The most important thing is its inventive concept. The pressure of the mutually independent and expandable sealing cavities 6 is adjusted by the pressure regulating mud pumping unit. Axial overexcavation, radial overexcavation and radial support are carried out by the overexcavation support mechanism 3 to construct the space for forming the lubricating mud film and correcting deviation. The lubricating mud pumping unit pumps mud into the radially overexcavated area to form the lubricating mud film. Furthermore, during the double-control and double-line close-fitting pipe jacking operation in a relatively soft formation, the precise control of the jacking direction is realized. It not only avoids the problems of difficult control and large disturbance to the surrounding soil caused by pumping out almost non-flowing mud outside the shield 1 to provide the deviation correction reaction force, but also avoids the problems that the deviation correction method of pumping out unbalanced slurry outside the shield 1 cannot be applied to relatively soft formations, cannot correct deviation continuously and cannot be applied to double-control and double-line close-fitting pipe jacking operations.

[0067] Among them, the overexcavation support mechanism 3 performs axial overexcavation on the shield 1, so that the face and the surrounding soil are isolated from each other in the axial and radial directions and advanced support is carried out to reduce the soil disturbance caused by the cutter head system during the excavation of the face. At the same time, the space radially overexcavated by the overexcavation support mechanism 3 outside the shield 1 can be used for pumping in lubricating mud to form the lubricating mud film. The lubricating mud film can not only isolate the surrounding soil from the rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operation, but also provide a certain torsional space for the precise alignment of the rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operation, and can also reduce the jacking resistance of the rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operation. At the same time, it can wrap the composite rubber layer 5 and extend the service life of the composite rubber layer 5.

[0068] The sealed cavities 6 are independent of each other, and the slurry filled inside will not overflow into the surrounding soft soil. By controlling the slurry filling amount of each sealed cavity 6 through the pressure-regulating slurry pumping unit, different support reaction forces can be provided by the sealed cavities 6 on both sides respectively, and the support reaction force is stable and reliable. The slurry filling amount in each sealed cavity 6 can also be dynamically adjusted through the pressure-regulating slurry pumping unit, which not only avoids the problem that the flowing slurry in the prior art cannot provide a reliable support reaction force, but also solves the problems that the flowing slurry cannot be recovered and the non-flowing mud cannot be adjusted, that is, solves the problem that it is difficult to accurately control the jacking direction and position in the double-hole and double-line close-fitting pipe jacking operation caused by the unstable support reaction force and the inability to dynamically adjust.

[0069] It should be particularly noted that as Figure 6 shown, although the sealed cavity 6 bulges out of the shield 1 in the radial direction after being inflated by grouting in the sealed cavity 6, the over-excavation support mechanism 3 has carried out radial over-excavation in advance, and the lubricating slurry pumping unit pumps the lubricating slurry into the gap between the front end of the sealed cavity 6 and the soil body. Furthermore, not only the backfill space where the sealed cavity 6 bulges out of the shield 1 is eliminated, but also as the rectangular pipe jacking machine jacks forward, the slurry between the front end of the sealed cavity 6 and the soil body will be extruded between the outer surface of the composite rubber layer 5 and the surrounding soil body to automatically form a mud film.

[0070] Preferably, a pressure sensor is arranged in each sealed cavity 6. The dynamic measurement results of the pressure sensor are communicatively interconnected with the pressure-regulating slurry pumping unit and the lubricating slurry pumping unit. The pressure-regulating slurry pumping unit and the lubricating slurry pumping unit dynamically adjust the grouting pressure and grouting flow according to the real-time measurement results of the pressure sensor and the distance measuring device 4.

[0071] Preferably, the grouting pressure of the lubricating slurry pumping unit is linked with the pressure of the sealed cavity 6, and the grouting volume is calculated according to Q = 0.5v·D·L (v is the jacking speed, D is the pipe diameter, and L is the pipe joint length) to avoid the slurry pressure from damaging the soil balance.

[0072] Preferably, each sealed cavity 6 is independently configured with a dual-channel hydraulic servo system (main pump + standby pump), the pressure regulation accuracy is ±0.03 MPa, and the expansion amount of the sealed cavity 6 is adjusted in real time according to the formation resistance to ensure that the pipe jacking axis deviation in the double-hole and double-line close-fitting pipe jacking operation is ≤ 5 mm. The cross-pressure coupling algorithm is adopted, and the two independent and expandable sealed cavities 6 are linked and regulated to balance the lateral soil pressure difference.

[0073] Preferably, a replaceable alloy wear-resistant sheet (3mm thick, HRC60 hardness) is embedded in the wear area of ​​the composite rubber layer 5 and fixed by countersunk bolts. When the single wear amount is greater than 1mm, an early warning is triggered. A ceramic coating (Al2O3-TiO2 composite layer, 0.2mm thick) is sprayed on the contact surface between the shield shell 1 and the composite rubber layer 5 to reduce the risk of rubber aging caused by friction heat.

[0074] Preferably, a barbed sealing lip (rubber material, Shore hardness 70A) is provided at the edge of the connection between the composite rubber layer 5 and the shield shell 1, and is embedded in the dovetail groove (depth 5mm) reserved in the shield shell 1 to ensure the sealing effect between the composite rubber layer 5 and the shield shell 1. It should be particularly noted that even if a small amount of mud leaks between the composite rubber layer 5 and the shield shell 1, it will not affect the normal construction of the jacking operation, but can also promote the formation of a lubricating mud film.

[0075] Preferably, an optical fiber strain sensor array (spacing 50 mm) is embedded in the composite rubber layer 5 to monitor the local stretching rate. When the threshold value (≥5%) is exceeded, the pressure is automatically relieved and an alarm is sounded 57. After every 20 rings of excavation, an industrial endoscope is used to check the sealing of the connection between the composite rubber layer 5 and the shield shell 1. If the crack depth is greater than 1 mm or the bulge area is greater than 3%, the machine is immediately stopped and replaced.

[0076] Preferably, a graphite-epoxy resin coating is pre-coated on the outer surface of the composite rubber layer 5, and the graphite-epoxy resin coating interacts with the lubricating mud film to form a rolling friction interface during the jacking process.

[0077] ‌Preferably, emergency redundancy design is performed, and each sealed cavity 6 is divided into 3 independent chambers, and the fault area is isolated by a solenoid valve to ensure that the remaining area can still maintain 70% of the steering capacity after a single chamber is damaged. A fast filling and discharge module is configured to quickly shrink the sealed cavity 6 when encountering hard rock jam to avoid extrusion and damage.

[0078] On the basis of the above embodiments, as a preferred embodiment of a rectangular pipe jacking machine for double-hole double-line close pipe jacking operations, the composite rubber layer 5 includes an inner aramid fiber reinforced layer 501, a middle honeycomb polyurethane buffer layer 502, and an outer high wear-resistant rubber matrix 503, the outer layer surface is embedded with silicon carbide particles and is provided with a guide groove 504 for guiding soil particles to discharge backwards, and the guide groove 504 is arranged at an axial inclination relative to the shield shell 1.

[0079] Among them, the inner aramid fiber reinforcement layer 501 has high tensile strength. The middle honeycomb polyurethane buffer layer 502 can absorb formation vibration energy through cavity deformation, reducing the stress peak when the sealing cavity 6 is pressurized. After the outer high-wear-resistant rubber matrix 503 is embedded with silicon carbide particles, the friction coefficient with the soil can be reduced to less than 0.2, while resisting scratches from hard rock debris. Under the combined action of the lubricating mud film and the diversion groove 504, it can facilitate the guiding of soil particles along the groove to the annular clearance area behind the pipe jacking machine, enabling the soil particles to quickly detach from the composite rubber layer 5 and preventing local pressure concentration caused by the accumulation of soil particles on the surface of the composite rubber layer 5.

[0080] Preferably, the tensile strength of the aramid fiber reinforcement layer 501 is selected to be ≥2000 MPa, the pore diameter of the honeycomb polyurethane buffer layer 502 is selected to be 3 - 5 mm, and the particle size of the silicon carbide particles is 0.5 - 1 mm. Since the maximum particle size of the formation is usually less than 1.5 mm, the groove depth of the diversion groove 504 is set to be greater than 2 mm, and the groove spacing is set to be 10 - 15 mm to ensure that the soil particles can be continuously discharged backward.

[0081] The composite rubber layer 5 can withstand continuous jacking friction and wear, and the single - continuous construction wear rate can be controlled within 0.3 - 0.5 mm / km. The thickness of the composite rubber layer 5 is designed to be ≥25 mm. When the wear amount exceeds 30% of the initial thickness (i.e., the remaining thickness < 17.5 mm), it needs to be replaced, and the theoretical maximum wear distance is much greater than 1000 m.

[0082] Preferably, the slurry used to form the lubricating mud film is selected as bentonite - polymer composite slurry, and the slurry viscosity is selected to be 80 - 100 Pa·s. The lubricating mud film and the inclined diversion groove 504 cooperate to form a "soil particle - slurry mixed fluidized discharge" mode during the jacking process, which can effectively reduce the frictional resistance between the soil particles and the groove wall of the diversion groove 504. It can be measured that the jacking resistance can be significantly reduced and the service life of the composite rubber layer 5 can be extended.

[0083] On the basis of the above - mentioned embodiments, as Figure 2 shown, as a preferred embodiment of the rectangular pipe jacking machine for double - hole and double - line close - fitting pipe jacking operation, a receiving groove 101 for accommodating the composite rubber layer 5 is provided on the outer part of the shield 1. When the pressure - regulating mud pumping unit does not pump pressure - regulating mud into the sealing cavity 6, the outer surface of the composite rubber layer 5 is flush with the outer surface of the shield 1. During the normal tunneling process without the need for steering, it can not only avoid excessive wear of the composite rubber layer 5 but also prevent the occurrence of backfill due to the protrusion of the sealing cavity 6.

[0084] On the basis of the above - mentioned embodiments, as a preferred embodiment of the rectangular pipe jacking machine for double - hole and double - line close - fitting pipe jacking operation, as Figure 3As shown, at the edge where the composite rubber layer 5 is connected to the shield shell 1, a deployable and foldable wavy corrugated structure 505 is formed through a laser cutting process. Preferably, a multi-layer polyester fiber base fabric is used to stack and form the wavy corrugated structure 505. When the slurry is not injected into the sealing cavity 6, it is in a compressed and folded state, and after the slurry is injected, it can be expanded to the designed size, which can further avoid backfill during the normal tunneling process without the need for alignment.

[0085] Based on the above embodiments, as a preferred embodiment of a rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operations, as Figure 2 、 Figure 3 、 6 and Figure 7 shown, a hardened alloy protection plate 102 is provided on the shield shell 1 outside the wavy corrugated structure 505, and a driving mechanism 7 is provided inside the shield shell 1 to drive the hardened alloy protection plate 102 to extend out of the shield shell 1 and tilt to cover the outside of the wavy corrugated structure 505 or be retracted into the shield shell 1.

[0086] Preferably, as Figure 6 shown, an inclined through hole is provided on the shield shell 1, and the hardened alloy protection plate 102 is inserted and fitted with the through hole, and a sealing structure is provided between the two. A rack 701 is provided at one end of the hardened alloy protection plate 102 located inside the shield shell 1. The driving mechanism 7 is a gear driving mechanism for driving the rack 701. Preferably, a driving motor is used as the power source, and a speed reducer is used for speed reduction and torque increase. The output end of the speed reducer is connected to the gear driving the rack 701. Since the driving motor, the speed reducer and the gear are all common knowledge, they will not be described in detail in this embodiment and the accompanying drawings of the specification.

[0087] Preferably, the material of the hardened alloy protection plate 102 is high manganese steel or functionally graded materials (Functionally Gradable Materials), and its representative materials include tungsten carbide infiltration (WCSP) and chromium carbide composite materials (Cr2C3+Q235). Tungsten carbide infiltration (WCSP): Tungsten carbide is combined with the steel matrix through ion implantation infiltration technology, with high hardness on the surface (tungsten carbide) and high toughness in the core, suitable for extremely abrasive environments; Chromium carbide composite materials (Cr2C3+Q235): It has both high wear resistance and the strength of the matrix material.

[0088] Based on the above embodiments, as a preferred embodiment of a rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operations, composite rubber layers 5 are also connected to the upper side and / or the lower side of the outside of the shield shell 1 to form independent and expandable sealing cavities 6, and each sealing cavity 6 is independently connected to a pressure-regulating slurry pumping unit, and the pressure-regulating slurry pumping unit dynamically controls the pressure in each sealing cavity 6.

[0089] Based on the above embodiments, as a preferred embodiment of the rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operations, as Figure 2 shown, several independent sealing cavities 6 are provided on each side of the outside of the shield shell 1. Each of the sealing cavities 6 is strip-shaped and extends along the axial direction of the shield shell 1, and the sealing cavities 6 are arranged at intervals in parallel. Preferably, a distance measuring device 4 is provided between adjacent sealing cavities 6.

[0090] Based on the above embodiments, as a preferred embodiment of the rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operations, as Figures 7 to 10 shown, the over-excavation support mechanism 3 includes a driving motor 302 connected to a driving oil cylinder 301. When the driving oil cylinder 301 expands and contracts, it can drive the driving motor 302 to move synchronously. The driving motor 302 is connected to a milling head 304 through a driving shaft 303. The excavation contour of the milling head 304 exceeds the outer contour of the shield shell by 10-20 mm. The driving motor 302 drives the milling head 304 to rotate through the driving shaft 303 to achieve radial over-excavation. The structure of the milling head 304 is the same as that of the prior art, including a rotary body main structure. The diameter of the front end of the main structure is smaller than that of the rear end, and a spiral guide substrate is provided on the outer periphery of the main structure. A plurality of spaced cutting teeth are connected to the top of the guide substrate.

[0091] Based on the above embodiments, as a preferred embodiment of the rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operations, one end of the driving oil cylinder 301 is connected to the shield shell 1, and the other end is connected to the driving motor 302 through a sliding box body 305. The sliding box body 305 is slidably matched with the shield shell 1. The driving motor 302 and the driving shaft 303 are both arranged in the sliding box body 305. The contour of the front end part of the sliding box body 305 exceeds the outer contour of the shield shell by 20-50 mm. The part of the sliding box body 305 that is larger than the outer contour of the shield shell 1 can push the over-excavated soil body to the working face, thereby providing a mud pumping space for the lubricating mud pumping unit, facilitating the storage of a certain amount of mud between the sealing cavity 6, the surrounding soil body and the outer wall of the shield shell 1. Then, during the jacking process, the stored mud can be pressed between the composite rubber layer 5 and the surrounding soil body to form a lubricating mud film.

[0092] Preferably, as Figure 10 shown, the front end part of the sliding box body 305 is provided with an end structure 310 with a right-angled triangle cross-section. The end structure is the part where the sliding box body 305 exceeds the outer contour of the shield shell 1 by 20-50 mm.

[0093] Preferably, the driving motor 302 is fixed in the sliding box body 305 through a motor base. The output shaft of the driving motor 302 is connected to the driving shaft 303 through a speed reducer 306. The speed reducer 306 is fixed in the sliding box body 305 through a flange plate. An outer box body 307 sleeved outside the sliding box body 305 is arranged in the shield shell 1. When the driving oil cylinder 301 gradually extends as the milling head 304 rotates, it will drive the sliding box body 305 to extend along the outer box body 307. The top plate of the sliding box body 305 serves as a support structure after extension to carry out advanced support for the surrounding soil mass.

[0094] Preferably, a spiral blade 308 is arranged on the driving shaft 303. The front end of the spiral blade 308 is transitionally connected to the diversion base plate on the milling head 304. Matching slag discharge ports 309 are arranged on the sliding box body 305 and the outer box body 307. The slag discharge ports 309 are communicated with the soil bin of the excavation system. Then, when the overexcavation support mechanism 3 performs overexcavation, the directly excavated muck can be discharged into the soil bin, which not only avoids soil stress concentration but also avoids the occurrence of soil backfill, facilitating the formation of the lubricating mud film and the precise control of the jacking direction.

[0095] On the basis of the above embodiments, as a preferred embodiment of the rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operation, the lubricating grouting hole 2011 of the lubricating mud pumping unit is arranged on the shield shell 1 at the position of the driving oil cylinder 301. The sealing cavity 6, the pressure regulating grouting hole 2021 and the pressure regulating slurry discharge hole 2022 are all located on the shield shell 1 behind the driving oil cylinder 301. The concrete mortar pumping channel of the reinforced mortar pumping unit grouts outward through the shield tail seal brush 103.

[0096] The details not elaborated in the present invention are all conventional technical means well known to those skilled in the art.

[0097] The above content shows and describes the basic principle, main features and beneficial effects of the present invention. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A rectangular pipe jacking machine for closely fitting double-hole and double-line pipe jacking operations, comprising a shield shell, an excavation system and a grouting system, characterized in that: At the front end of the shield shell, there are several independently telescopic overexcavation support mechanisms. On the side, there is a spacing measurement device for measuring the distance from the segment in close contact. On the left and right sides of the outside, composite rubber layers are respectively connected to form two independent and expandable sealing cavities. The grouting system includes a lubricating mud pumping unit for pumping mud between the composite rubber layer and the inner wall of the tunnel to form a lubricating mud film, a pressure-regulating mud pumping unit for pumping or discharging mud into or from the two sealing cavities respectively, and a reinforcement mortar pumping unit for pumping concrete mortar to the tail outside the shield shell; the segment in close contact is the outer wall of another tunnel where the pipe jacking operation has been completed. During the jacking process, each overexcavation support mechanism successively overexcavates the formation space of the lubricating mud film outside the shield shell contour. The lubricating mud pumping unit pumps mud into the formation space to form the lubricating mud film. When the detection result of the spacing measurement device is abnormal, the pressure-regulating mud pumping unit adjusts the pressure of the two sealing cavities, so that the shield shell returns to the target position under the reaction force of the sealing cavities.

2. The rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operation according to claim 1, characterized in that: The composite rubber layer includes an inner aramid fiber reinforced layer, a middle honeycomb polyurethane buffer layer, and an outer high-wear-resistant rubber matrix. Silicon carbide particles are embedded on the outer surface, and diversion grooves for guiding soil particles to be discharged backward are provided. The diversion grooves are arranged obliquely relative to the axial direction of the shield shell.

3. The rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operation according to claim 1 or 2, characterized in that: A receiving groove for accommodating the composite rubber layer is provided on the outside of the shield shell. When the pressure-regulating mud pumping unit does not pump pressure-regulating mud into the sealing cavity, the outer surface of the composite rubber layer is flush with the outer surface of the shield shell.

4. The rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operation according to claim 3, characterized in that: At the edge where the composite rubber layer is connected to the shield shell, a deployable and foldable wavy fold structure is formed by laser cutting technology.

5. The rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operation according to claim 4, characterized in that: On the shield shell, there is a hardened alloy protection plate located outside the wavy fold structure. Inside the shield shell, there is a driving mechanism for driving the hardened alloy protection plate to extend out of the shield shell and obliquely cover outside the wavy fold structure or be received into the shield shell.

6. The rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operations according to any one of claims 1-2, 4-5, characterized in that: On the upper side and / or lower side of the outside of the shield shell, a composite rubber layer is also connected to form an independent and expandable sealing cavity.

7. The rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operation according to claim 6, characterized in that: On each side of the outside of the shield shell, several independent sealing cavities are provided. Each sealing cavity is strip-shaped and extends along the axial direction of the shield shell. The sealing cavities are arranged at intervals in parallel.

8. The rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operations according to any one of claims 1-2, 4-5, and 7, characterized in that: The overexcavation support mechanism includes a driving motor driven by a driving oil cylinder. The driving motor is connected with a milling head through a driving shaft. The excavation contour of the milling head exceeds the outer contour of the shield shell by 10 - 20 mm.

9. The rectangular pipe jacking machine for the double-hole and double-line close-fitting pipe jacking operation according to claim 8, characterized in that: One end of the driving oil cylinder is connected to the shield shell, and the other end is connected to the driving motor through a sliding box body. The sliding box body is in sliding fit with the shield shell. The driving motor and the driving shaft are both arranged in the sliding box body. The contour of the front end of the sliding box body exceeds the outer contour of the shield shell by 20 - 50 mm. A spiral blade for discharging overexcavated soil to the soil bin is arranged on the driving shaft.

10. The rectangular pipe jacking machine for double-hole and double-line close-fitting pipe jacking operation according to claim 9, characterized in that: The mud pumping channel of the lubricating mud pumping unit is arranged on the shield shell at the position of the driving oil cylinder. The sealing cavity and the mud pumping channel of the sealing cavity are located on the shield shell behind the driving oil cylinder. The concrete mortar pumping channel of the reinforcement mortar pumping unit passes through the shield tail seal brush.

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