Round-corner rectangular single-hole shield tunneling system and tunneling method thereof

Abstract

The invention discloses a rounded rectangular single-hole shield tunneling system which comprises a first shield system, a second shield system and a cutting system. The first shield system comprises a first cutter head, a first threaded cylinder rotationally connected to the rear portion of the first cutter head and a first supporting system rotationally connected to the rear portion of the first threaded cylinder. The second shield system comprises a second cutter head, a second threaded cylinder rotationally connected to the rear portion of the second cutter head and a second supporting system rotationally connected to the rear portion of the second threaded cylinder. According to the shield tunneling system and the tunneling method thereof, tunneling forming of a rounded rectangular tunnel can be effectively achieved, the two adopt a thread structure to alternately serve as a support to enable the other one to advance, cutting force and propelling force can be more uniform in a thread-matched advancing mode, the tunneling speed is more stable, and the tunneling efficiency is improved. And meanwhile, the configuration of a propelling system can be simplified, the space of the shield tunneling machine is effectively saved, and complex structures in the shield tunneling machine are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of geotechnical engineering, and in particular to a rounded rectangular single-hole shield tunneling system and a tunneling method thereof. Background Art

[0002] In urban infrastructure construction, tunnels are important channels connecting various areas of the city. With the continuous expansion of urban scale and the growing demand for underground space utilization, the construction technology and methods of tunnel engineering are continuously improving and developing. As one of the commonly used construction methods in tunnel engineering, the shield tunneling method has the advantages of fast construction speed, high safety, and little impact on the surrounding environment. It is widely used in subways, water conservancy, highways and other fields.

[0003] Existing shield tunneling methods mainly use circular cross-sections for tunneling. However, unlike tunnels on highways or railways in the wild, where the two-way lanes are separated and can usually be excavated separately, mountain highway tunnels in cities are preferably two-way, which can ensure the continuity of the highway and save precious land resources in the city. That is, the cross-section of the tunnel is preferably a rounded rectangle, which can meet the requirements of a single-hole two-way lane, and even if a one-way lane is used, the space utilization rate can be greatly improved; but existing shield machines are difficult to achieve the excavation of such tunnels. Summary of the invention

[0004] The object of the present invention is to provide a rounded rectangular single-hole shield tunneling system and a tunneling method thereof. The rounded rectangular single-hole shield tunneling system and a tunneling method thereof adopt two shield systems arranged side by side and utilize the threaded structure of their threaded barrels to alternately perform tunneling operations, which can not only effectively realize the tunneling and forming of the rounded rectangular tunnel, but also the two use the threaded structure to alternately support the other to advance, and the threaded coordination forward mode can make the cutting force and the propulsion force more uniform, and the tunneling speed more stable. At the same time, it can also simplify the configuration of the propulsion system, effectively save the space of the shield machine, reduce the complex structure inside the shield machine, reduce the manufacturing cost of the shield machine, increase the life of the shield machine, and reduce the use cost of the shield machine.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a rounded rectangular single-hole shield tunneling system, comprising a first shield system, a second shield system and a cutting system; the first shield system comprises a first cutter head, a first threaded barrel rotatably connected to the rear of the first cutter head, and a first support system rotatably connected to the rear of the first threaded barrel; the second shield system comprises a second cutter head, a second threaded barrel rotatably connected to the rear of the second cutter head, and a second support system rotatably connected to the rear of the second threaded barrel; the outer circumferential surface of the first threaded barrel is provided with a first spiral convex strip; the outer circumferential surface of the second threaded barrel is provided with a second spiral convex strip; the first On the spiral convex strip, a first interference strip protrudes outward on one side extending along its trajectory, and the first interference strip is perpendicular to the first spiral convex strip; on the second spiral convex strip, a second interference strip protrudes outward on one side extending along its trajectory, and the second interference strip is perpendicular to the second spiral convex strip; the first spiral convex strip and the second spiral convex strip have the same rotation direction and mesh with each other, and the first interference strip interferes with the second interference strip; a power system independently drives the first cutter disc, the second cutter disc, the first threaded barrel and the second threaded barrel to rotate; only one of the first threaded barrel and the second threaded barrel rotates at the same time, and relies on the other stationary one as support to advance through threaded cooperation.

[0006] Wherein, the cutting system includes a cutting mechanism and a transmission belt; the transmission belt is arranged below the cutting mechanism to discharge the rock and soil dropped by the wire cutting.

[0007] Among them, the outer cylinders of the first support system and the second support system are respectively provided with through slots extending in the axial direction at the opposite positions near the top; the cutting lines of the cutting mechanism and the second wire cutting mechanism respectively pass through the through slots and span between the outer cylinders of the first support system and the second support system; the cutting mechanism and the second wire cutting mechanism also respectively include guide rails arranged in the outer cylinders of the first support system and the second support system and extending in the axial direction thereof; the cutting line is tensioned by a tensioning wheel, and the tensioning wheel is driven to rotate by a motor; the fixed frame of the motor is slidably sleeved on the guide rail, and is driven to move along the guide rail through a telescopic rod controlled by a control system, so that during the movement of the first support system and the second support system, the cutting line always remains vertical to the first shield system and the second shield system and translates.

[0008] Among them, a rotating power shaft is respectively provided at the center of the first shield system and the second shield system; a fixed sleeve that does not rotate is provided outside the power shaft; a spacing is set between the fixed sleeve and the power shaft; the front end of the power shaft directly drives the cutter disc to rotate; a first coupling sleeve is respectively provided at the position corresponding to the threaded barrel on the power shaft; a gear is provided at the fixed sleeve outside the first coupling sleeve; the fixed sleeve is disconnected and gives way at the position corresponding to the first coupling sleeve and the gear; an inner gear ring is provided at a spacing inside the threaded barrel; the outer circumference of the inner gear ring is fixedly connected to the inner wall of the threaded barrel by a plurality of connecting rods; a planetary gear mechanism is provided between the inner gear ring and the gear; the rotation center of the planetary gear bracket of the planetary gear mechanism is a second coupling sleeve; the second coupling sleeve is sleeved on the fixed sleeve.

[0009] Among them, the first coupling sleeve includes a shell; the middle part of the shell is enlarged in diameter, the two ends are reduced in diameter, and the two ends are respectively sealed and rotatably sleeved on the power shaft; the middle part of the shell and the power shaft enclose a liquid cavity; the liquid cavity is filled with electrorheological fluid; electrodes are also respectively provided on the inner wall of the shell and the surface of the power shaft, and an external circuit applies a strong electric field to the electrorheological fluid through the electrodes to control the viscosity of the electrorheological fluid; the structure of the second coupling sleeve is the same as that of the first coupling sleeve.

[0010] Wherein, the electrode is wedge-shaped, and its vertical surface faces the flow direction of the electrorheological fluid.

[0011] A method for excavating a rounded rectangular single hole comprises the following steps:

[0012] Step ①, the first shield system, the second shield system and the cutting system are installed; the first shield system and the second shield system are arranged side by side, and the cutting system spans between the first shield system and the second shield system;

[0013] Step ②, start the power system, the power shaft in the first shield system directly drives the first cutter head to rotate and advance, and uses an external circuit to apply an electric field to the electrorheological fluid in the first coupling sleeve and the second coupling sleeve in the first shield system, so as to change the viscosity of the electrorheological fluid, so that the gear in the first threaded barrel drives the first threaded barrel to rotate through the planetary gear; at this time, the second threaded barrel does not rotate, and the first threaded barrel uses the second threaded barrel as a support, and advances through the threaded cooperation under rotation;

[0014] Step ③, disconnecting the electric field applied to the electrorheological fluid in the first shield system, so that the first threaded barrel stops rotating; the power shaft in the second shield system directly drives the second cutter head to rotate and advance, and uses an external circuit to apply an electric field to the electrorheological fluid in the first coupling sleeve and the second coupling sleeve in the second shield system, so as to change the viscosity of the electrorheological fluid, so that the gear in the second threaded barrel drives the second threaded barrel to rotate through the planetary gear, so that the first threaded barrel is used as a support, and the second threaded barrel is advanced through the threaded fit under rotation;

[0015] Step ④, alternately performing steps ② and ③ can realize the alternating excavation of the two shield systems; in this process, the cutting line always keeps vertical translation of the first shield system and the second shield system, cutting the rock and soil between the upper parts of the two shield systems that have not been excavated by the cutter disc; the cut rock and soil falls onto the transmission belt under the action of gravity and is transported out;

[0016] Step ⑤, during the alternating excavation of the two shield systems, reinforcement work of the tunnel wall is performed at the first support system and the second support system;

[0017] Step ⑥, after the excavation is completed and the shield system withdraws, use an excavator to excavate the unexcavated rock and soil between the lower parts of the two shield systems.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention adopts two shield systems arranged side by side and utilizes the threaded structure of the threaded barrel to perform excavation operations alternately, which can not only effectively realize the excavation and forming of a rounded rectangular tunnel, but also the two use the threaded structure to alternately support the other to advance. In this process, the restrictions of the excavated tunnel on the shield system in various directions are also utilized to ensure the stability of one of the shield systems as a support; and the threaded cooperation method is utilized, and the continuity of the threaded cooperation is utilized, and the cutter head rotates and excavates while advancing, and the two are performed synchronously and integrally, so that the rotation of the cutter head and the advancement of the shield system can be guaranteed. The existing shield machine cannot achieve this by pushing the cutter head forward through the hydraulic cylinder. Therefore, the present invention can make the cutting force and the propulsion force more uniform, the excavation speed more stable, and at the same time can simplify the configuration of the propulsion system, effectively save the space of the shield machine, reduce the complex structure inside the shield machine, reduce the manufacturing cost of the shield machine, increase the life of the shield machine, and reduce the use cost of the shield machine.

[0020] 2. The present invention uses electrorheological fluid and electrodes to control the viscosity of the electrorheological fluid in the first coupling sleeve and the second coupling sleeve in the shield system, thereby achieving precise control of the rotation of the threaded barrel; the characteristics of the electrorheological fluid under the action of the electric field are cleverly utilized, and the viscosity of the electrorheological fluid is instantly and reversibly changed by the electric field, so that the linkage torque of the power shaft and the gear can be directly controlled, and the two states of linkage rotation and contact linkage rotation can be switched at any time; at the same time, the revolutionability of the planetary wheel relative to the fixed sleeve can be controlled, so that the transmission ratio can be adjusted by adjusting the revolution of the planetary wheel without replacing the planetary wheel and other structures, which not only improves the stability and deceleration capacity of the driven rotation of the threaded barrel, but also can flexibly adjust the deceleration ratio within a certain range, and improves the capacity of the shield system while simplifying the structure.

[0021] 3. The cutting line of the present invention always remains perpendicular to the translation of the first shield system and the second shield system, and the accuracy and efficiency of the cutting process are also ensured during the alternating excavation of the two shield systems. In addition, after the excavation is completed, the unexcavated rock and soil between the lower parts of the two shield systems is excavated with an excavator, which is simple to operate and cooperates with existing equipment, which helps to improve the overall excavation efficiency, reduce construction costs, and further streamline the internal structure of the shield system.

[0022] 4. The electrode of the present invention is wedge-shaped, and its vertical surface faces the flow direction of the electrorheological fluid, so that it has the function of applying an electric field and also serves as a torque transmission member, killing two birds with one stone and simplifying the internal structure of the coupling sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the initial state of the first shield system and the second shield system of the present invention;

[0024] Figure 2 It is a schematic diagram of the first shield system of the present invention when tunneling with the second shield system as support;

[0025] Figure 3 It is a schematic diagram of the second shield system of the present invention when excavating with the first shield system as support;

[0026] Figure 4 is a schematic diagram of a first shield system of the present invention;

[0027] Figure 5 It is a schematic diagram of the thread matching of two shield systems of the present invention;

[0028] Figure 6 It is a schematic diagram of the cooperation between the first spiral convex strip and the first interference strip and the second spiral convex strip and the second interference strip of the present invention;

[0029] Figure 7 It is a cross-sectional schematic diagram of the present invention at the first coupling sleeve;

[0030] Figure 8 It is a partial schematic cross-sectional view of the first coupling sleeve of the present invention;

[0031] Fig. 9 It is a cross-sectional schematic diagram of the second coupling sleeve of the present invention;

[0032] Fig.10 is a schematic diagram of a cutting system of the present invention;

[0033] Fig.11 It is a schematic diagram of the present invention using the peristaltic cylinder at the rear as a support to push the peristaltic cylinder at the front forward;

[0034] Fig.12It is a schematic diagram of the present invention using the peristaltic cylinder at the front as a support to pull the peristaltic cylinder at the rear forward;

[0035] Fig.13 It is a schematic diagram of the peristaltic cylinder located at the front of the present invention pulling the peristaltic cylinder located at the rear to the front;

[0036] Fig.14 This is a schematic diagram of the present invention again using the peristaltic cylinder at the rear as a support to push the peristaltic cylinder at the front forward.

[0037] In the figure: 11, the first cutter disc; 12, the first threaded cylinder; 121, the first spiral convex strip; 122, the first interference strip; 13, the first support system; 14, the cutting mechanism; 15, the transmission belt; 181, the cutting line; 182, the guide rail; 183, the tensioning wheel; 184, the motor; 21, the second cutter disc; 22, the second threaded cylinder; 221, the second spiral convex strip; 222, the second interference strip; 23, the second support system; 31, the power shaft; 32, the fixed sleeve; 33, the first coupling sleeve; 331, the shell; 332, the liquid chamber; 333, the electrode; 34, the gear; 35, the inner gear ring; 36, the planetary gear mechanism; 37, the second coupling sleeve; 38, the connecting rod; 41, the peristaltic cylinder; 42, the first hydraulic rod; 43, the support plate; 44, the second hydraulic rod. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] See also Figures 1 to 14The present invention provides a technical solution: a rounded rectangular single-hole shield tunneling system, comprising a first shield system, a second shield system and a cutting system; the first shield system comprises a first cutter head 11, a first threaded barrel 12 rotatably connected to the rear of the first cutter head 11, and a first support system 13 rotatably connected to the rear of the first threaded barrel 12; the second shield system comprises a second cutter head 21, a second threaded barrel 22 rotatably connected to the rear of the second cutter head 21, and a second support system 23 rotatably connected to the rear of the second threaded barrel 22; the outer circumferential surface of the first threaded barrel 12 is provided with a first spiral convex strip 121; the outer circumferential surface of the second threaded barrel 22 is provided with a second spiral convex strip 221; on the first spiral convex strip 121, along its trajectory The first and second spiral ridges 221 extend along a trajectory, with a first interference strip 122 protruding outwardly on one side, the first interference strip 122 being perpendicular to the first spiral ridge 121; the second spiral ridge 221 extends along its trajectory, with a second interference strip 222 protruding outwardly on one side, the second interference strip 222 being perpendicular to the second spiral ridge 221; the first and second spiral ridges 121 and 221 have the same rotation direction and mesh with each other, and the first interference strip 122 and the second interference strip 222 interfere with each other; a power system independently drives the first cutter disc 11, the second cutter disc 21, the first threaded barrel 12 and the second threaded barrel 22 to rotate; only one of the first and second threaded barrels 12 and 22 rotates at the same time, and relies on the other stationary one as support to advance through threaded cooperation.

[0040] Furthermore, the cutting system includes a cutting mechanism 14 and a transmission belt 15; the transmission belt 15 is arranged below the cutting mechanism 14 to discharge the rock and soil dropped by the wire cutting.

[0041] Furthermore, the outer tubes of the first support system 13 and the second support system 23 are respectively provided with through slits extending in the axial direction at the opposite positions near the top; the cutting lines 181 of the cutting mechanism 14 and the second wire cutting mechanism 16 pass through the through slits and span between the outer tubes of the first support system 13 and the second support system 23; the cutting mechanism 14 and the second wire cutting mechanism 16 also respectively include guide rails 182 arranged in the outer tubes of the first support system 13 and the second support system 23 and extending in the axial direction thereof; the cutting line 181 is tensioned by a tensioning wheel 183, and the tensioning wheel 183 is driven to rotate by a motor 184; the fixed frame of the motor 184 is slidably sleeved on the guide rail 182, and is driven to move along the guide rail 182 through a telescopic rod controlled by a control system, so that during the movement of the first support system 13 and the second support system 23, the cutting line 181 always remains vertical to the first shield system and the second shield system and translates.

[0042] Furthermore, a rotating power shaft 31 is respectively provided at the center of the first shield system and the second shield system; a fixed shaft sleeve 32 that does not rotate is provided on the outer surface of the power shaft 31; a spacing is set between the fixed shaft sleeve 32 and the power shaft 31; the front end of the power shaft 31 directly drives the cutter head to rotate; a first coupling sleeve 33 is respectively provided at the position corresponding to the threaded barrel on the power shaft 31; a gear 34 is fixedly provided outside the first coupling sleeve 33; the fixed sleeve 32 is disconnected and made way for the position corresponding to the first coupling sleeve 33 and the gear 34; an inner gear ring 35 is provided at a spacing inside the threaded barrel; the outer circumference of the inner gear ring 35 is fixedly connected to the inner wall of the threaded barrel by a plurality of connecting rods 38; a planetary gear mechanism 36 is provided between the inner gear ring 35 and the gear 34; the rotation center of the planetary gear bracket of the planetary gear mechanism 36 is a second coupling sleeve 37; the second coupling sleeve 37 is sleeved on the fixed shaft sleeve 32.

[0043] Furthermore, the first coupling sleeve 33 includes a shell 331; the shell 331 has an enlarged diameter in the middle and a reduced diameter at both ends, and the two ends are respectively sealed and rotatably sleeved on the power shaft 31; the middle of the shell 331 and the power shaft 31 enclose a liquid cavity 332; the liquid cavity 332 is filled with an electrorheological fluid; electrodes 333 are also respectively provided on the inner wall of the shell 331 and the surface of the power shaft 31, and an external circuit applies a strong electric field to the electrorheological fluid through the electrodes 333 to control the viscosity of the electrorheological fluid; the second coupling sleeve 37 has the same structure as the first coupling sleeve 33.

[0044] Furthermore, the electrode 333 is wedge-shaped, and its vertical surface faces the flow direction of the electrorheological fluid.

[0045] A method for excavating a rounded rectangular single hole comprises the following steps:

[0046] Step ①, the first shield system, the second shield system and the cutting system are installed; the first shield system and the second shield system are arranged side by side, and the cutting system spans between the first shield system and the second shield system;

[0047] Step ②, start the power system, the power shaft 31 in the first shield system directly drives the first cutter head 11 to rotate and advance, and uses an external circuit to apply an electric field to the electrorheological fluid in the first coupling sleeve 33 and the second coupling sleeve 37 in the first shield system, so as to change the viscosity of the electrorheological fluid, so that the gear 34 in the first threaded barrel 12 drives the first threaded barrel 12 to rotate through the planetary gear 36; at this time, the second threaded barrel 22 will not rotate, and the first threaded barrel 12 uses the second threaded barrel 22 as a support, and advances through the threaded fit under rotation;

[0048] Step ③, disconnect the electric field applied to the electrorheological fluid in the first shield system, so that the first threaded barrel 12 stops rotating; the power shaft 31 in the second shield system directly drives the second cutter head 21 to rotate and advance, and uses an external circuit to apply an electric field to the electrorheological fluid in the first coupling sleeve 33 and the second coupling sleeve 37 in the second shield system to change the viscosity of the electrorheological fluid, so that the gear 34 in the second threaded barrel 22 drives the second threaded barrel 22 to rotate through the planetary gear 36, so that it uses the first threaded barrel 12 as a support and advances through the threaded fit under rotation;

[0049] Step ④, alternately performing steps ② and ③ can realize the alternating excavation of the two shield systems; in this process, the cutting line 181 always keeps vertical translation of the first shield system and the second shield system, cutting the rock and soil between the upper parts of the two shield systems that have not been excavated by the cutter disc; the cut rock and soil falls to the transmission belt 15 under the action of gravity and is transported out;

[0050] Step ⑤, during the alternating excavation of the two shield systems, reinforcement work of the tunnel wall is performed at the first support system 13 and the second support system 23;

[0051] Step ⑥, after the excavation is completed and the shield system withdraws, use an excavator to excavate the unexcavated rock and soil between the lower parts of the two shield systems.

[0052] In addition, on the basis of the above scheme, in order to further improve the tunneling capacity of the shield system and provide a backup tunneling power scheme; at least two peristaltic cylinders 41 distributed front and back are arranged between the first threaded cylinder 12 and the first support system 13 and between the second threaded cylinder 22 and the second support system 23; the peristaltic cylinder 41 is rotationally connected to the threaded cylinder; the two peristaltic cylinders 41 are connected by a plurality of first hydraulic rods 42; the diameter of the peristaltic cylinder 41 is smaller than the diameter of the threaded cylinder, and a plurality of support plates 43 are evenly arranged on the outer circumferential surface of the peristaltic cylinder 41; the front end of the support plate 43 is hinged on the peristaltic cylinder 41, and the rear end extends obliquely outward, each support plate 43 corresponds to a second hydraulic rod 44, one end of the second hydraulic rod 44 is hinged on the peristaltic cylinder 41, and the other end is hinged to the middle of the support plate 43. When viewed from the side, the support plate 43, the surface of the peristaltic cylinder 41 and the second hydraulic rod 44 form an obtuse triangle; when the second hydraulic rod 44 is extended, the support plate 43 can be pushed outward so that the support plate 43 is pressed against the inner wall of the tunnel.

[0053] When additional thrust is needed, the support plate 43 of the peristaltic cylinder 41 at the rear is first unfolded and pressed against the inner wall of the tunnel. With the peristaltic cylinder 41 at the rear as support, the first hydraulic rod 42 is extended to push the peristaltic cylinder 41 at the front forward, thereby supplementing thrust for the cutter head and the threaded cylinder; see Fig.12 and 13After the first hydraulic rod 42 is extended to the limit, the support plate 43 of the peristaltic cylinder 41 at the front is expanded to press against the inner wall of the tunnel, and the support plate 43 of the peristaltic cylinder 41 at the rear is retracted; the first hydraulic rod 42 is shortened, and the peristaltic cylinder 41 at the front is used as a support to pull the peristaltic cylinder 41 at the rear forward, and this is repeated to achieve overall peristaltic advancement.

[0054] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A rounded rectangular single-hole shield tunneling system, characterized in that: The invention comprises a first shield system, a second shield system and a cutting system; the first shield system comprises a first cutter disc (11), a first threaded barrel (12) rotatably connected to the rear of the first cutter disc (11), and a first support system (13) rotatably connected to the rear of the first threaded barrel (12); the second shield system comprises a second cutter disc (21), a second threaded barrel (22) rotatably connected to the rear of the second cutter disc (21), and a second support system (23) rotatably connected to the rear of the second threaded barrel (22); the outer circumferential surface of the first threaded barrel (12) is provided with a first spiral convex strip (121); the outer circumferential surface of the second threaded barrel (22) is provided with a second spiral convex strip (221); on the first spiral convex strip (121), a first interference strip ( 122), the first interference strip (122) is perpendicular to the first spiral convex strip (121); on the second spiral convex strip (221), extending along its trajectory, a second interference strip (222) protrudes outward on one side, and the second interference strip (222) is perpendicular to the second spiral convex strip (221); the first spiral convex strip (121) and the second spiral convex strip (221) have the same rotation direction and mesh with each other, and the first interference strip (122) and the second interference strip (222) interfere with each other; a power system independently drives the first cutter disc (11), the second cutter disc (21), the first threaded barrel (12) and the second threaded barrel (22) to rotate; only one of the first threaded barrel (12) and the second threaded barrel (22) rotates at the same time, and relies on the other stationary one as support to advance through threaded cooperation.

2. A rounded rectangular single-hole shield tunneling system as claimed in claim 1, characterized in that: The cutting system comprises a cutting mechanism (14) and a transmission belt (15); the transmission belt (15) is arranged below the cutting mechanism (14) to discharge rock and soil dropped by the wire cutting.

3. A rounded rectangular single-hole shield tunneling system as claimed in claim 2, characterized in that: The outer tubes of the first support system (13) and the second support system (23) are respectively provided with through slits extending in the axial direction at the opposite positions near the top; the cutting lines (181) of the cutting mechanism (14) and the second wire cutting mechanism (16) respectively pass through the through slits and span between the outer tubes of the first support system (13) and the second support system (23); the cutting mechanism (14) and the second wire cutting mechanism (16) also respectively include two parts which are arranged in the outer tubes of the first support system (13) and the second support system (23), and respectively extend along the axial direction; The invention discloses an axially extending guide rail (182); a cutting line (181) is tensioned by a tensioning wheel (183), and the tensioning wheel (183) is driven to rotate by a motor (184); a fixing frame of the motor (184) is slidably sleeved on the guide rail (182), and is driven to move along the guide rail (182) by a control system through a telescopic rod, so that during the movement of the first support system (13) and the second support system (23), the cutting line (181) always keeps vertical translation of the first shield system and the second shield system.

4. A rounded rectangular single-hole shield tunneling system as claimed in claim 1, characterized in that: The first shield system and the second shield system are respectively provided with a rotating power shaft (31) at the center; the power shaft (31) is provided with a fixed shaft sleeve (32) that does not rotate; the fixed shaft sleeve (32) is spaced apart from the power shaft (31); the front end of the power shaft (31) directly drives the cutter head to rotate; a first coupling sleeve (33) is respectively provided at a position corresponding to the threaded barrel on the power shaft (31); a gear (34) is provided outside the fixed sleeve (32); The positions of the first coupling sleeve (33) and the gear (34) are disconnected and given way; an inner gear ring (35) is sleeved inside the threaded barrel; the outer circumference of the inner gear ring (35) and the inner wall of the threaded barrel are fixedly connected via a plurality of connecting rods (38); a planetary gear mechanism (36) is provided between the inner gear ring (35) and the gear (34); the rotation center of the planetary gear support of the planetary gear mechanism (36) is a second coupling sleeve (37); and the second coupling sleeve (37) is sleeved on the fixed sleeve (32).

5. A rounded rectangular single-hole shield tunneling system as claimed in claim 4, characterized in that: The first coupling sleeve (33) comprises a shell (331); the shell (331) has an enlarged diameter in the middle and a reduced diameter at both ends, and the two ends are respectively rotatably sleeved on the power shaft (31); the middle of the shell (331) and the power shaft (31) enclose a liquid cavity (332); the liquid cavity (332) is filled with an electrorheological fluid; electrodes (333) are respectively provided on the inner wall of the shell (331) and the surface of the power shaft (31); an external circuit applies a strong electric field to the electrorheological fluid through the electrodes (333) to control the viscosity of the electrorheological fluid; the second coupling sleeve (37) has the same structure as the first coupling sleeve (33).

6. A rounded rectangular single-hole shield tunneling system as claimed in claim 5, characterized in that: The electrode (333) is wedge-shaped, with its vertical surface facing the flow direction of the electrorheological fluid.

7. A method for excavating a rounded rectangular single hole, using the rounded rectangular single hole shield excavation system, comprising the following steps: Step ①, the first shield system, the second shield system and the cutting system are installed; the first shield system and the second shield system are arranged side by side, and the cutting system spans between the first shield system and the second shield system; Step ②, starting the power system, the power shaft (31) in the first shield system directly drives the first cutter head (11) to rotate and advance, and an external circuit is used to apply an electric field to the electrorheological fluid in the first coupling sleeve (33) and the second coupling sleeve (37) in the first shield system, so as to change the viscosity of the electrorheological fluid, thereby causing the gear (34) in the first threaded barrel (12) to drive the first threaded barrel (12) to rotate through the planetary gear (36); at this time, the second threaded barrel (22) does not rotate, and the first threaded barrel (12) uses the second threaded barrel (22) as support and advances through threaded engagement under rotation; Step ③, disconnecting the electric field applied to the electrorheological fluid in the first shield system, so that the first threaded barrel (12) stops rotating; the power shaft (31) in the second shield system directly drives the second cutter head (21) to rotate and advance, and using an external circuit to apply an electric field to the electrorheological fluid in the first coupling sleeve (33) and the second coupling sleeve (37) in the second shield system, so as to change the viscosity of the electrorheological fluid, thereby causing the gear (34) in the second threaded barrel (22) to drive the second threaded barrel (22) to rotate through the planetary gear (36), so that the first threaded barrel (12) is used as a support, and the second threaded barrel (22) is moved forward by the threaded engagement under rotation; Step ④, alternately performing steps ② and ③ can realize the alternating excavation of the two shield systems; during this process, the cutting line (181) always maintains vertical translation of the first shield system and the second shield system, cutting the rock and soil between the upper parts of the two shield systems that have not been excavated by the cutter disc; the cut rock and soil falls to the transmission belt (15) under the action of gravity and is transported out; Step ⑤, during the process of alternating excavation of the two shield systems, reinforcement work is performed on the tunnel wall at the first support system (13) and the second support system (23); Step ⑥, after the excavation is completed and the shield system withdraws, use an excavator to excavate the unexcavated rock and soil between the lower parts of the two shield systems.

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