Rectangular pipe jacking machine suitable for complex shallow soil covering stratum and deslagging method

Abstract

The invention discloses a rectangular pipe jacking machine suitable for a complex shallow soil covering stratum and a deslagging method. Relates to the technical field of pipe jacking equipment and construction. Comprising a shell, a pair of cutterhead assemblies, a spiral unearthing device and a belt conveyor, the shell comprises a front shell and a rear shell which are arranged front and back, a chest plate is arranged in the front shell, the pair of cutterhead assemblies are arranged on the chest plate side by side, each cutterhead assembly comprises a driving part and a cutterhead, the driving part is arranged on the chest plate and used for driving the cutterhead to rotate, and the spiral unearthing device is used for driving the cutterhead to rotate. The cutterheads are located on the front side of the breast plate, and the pair of cutterheads rotate relatively; according to the rectangular pipe jacking construction machine, the adaptability and the construction efficiency of rectangular pipe jacking construction under the condition that a large stone filling stratum exists in shallow covering soil are remarkably improved, the construction safety risk and the cost expenditure are effectively reduced, and the comprehensive benefits are quite remarkable.

Description

Technical Field

[0001] This invention relates to the field of pipe jacking equipment and construction technology, specifically to a rectangular pipe jacking machine and a slag removal method adapted to complex shallow overburden strata containing large rocks. Background Technology

[0002] With the deepening of urbanization, urban land resources are becoming increasingly scarce, and the development and utilization of underground space has become an inevitable trend in urban development. Against this backdrop, pipe jacking technology, with its advantages of good economy, high construction efficiency, and minimal impact on the surrounding environment, has been widely used in urban underground space development. Especially in densely built-up urban core areas with heavy traffic and complex underground pipelines, pipe jacking has become the preferred underground excavation technology.

[0003] In underground engineering construction, rectangular pipe jacking machines face multiple challenges when traversing strata containing large boulders, giant stones, boulders, and isolated rocks. On the one hand, large boulders can easily cause the cutterhead to jam and the cutters to wear out severely, and can also cause the auger to get stuck, even leading to the failure of the jacking operation. On the other hand, cutting large boulders requires powerful energy, and the resulting violent vibrations can severely disturb the surrounding soil, damage the stability of the strata, and thus cause ground instability and surface collapse, directly endangering construction safety.

[0004] Traditional rectangular pipe jacking machines are equipped with spiral excavators with outer diameters of 426mm, 570mm, and 720mm. However, due to limitations in the cylinder wall thickness, the gap between the spiral blades and the inner wall of the cylinder, and the diameter of the spiral shaft, the actual size of stones that can pass through is very limited. In shallow overburden fill strata, large stones, boulders, and pebbles are widely distributed, and their shape, size, and distribution are random, easily interfering with the rectangular pipe jacking machine's excavation and spiral excavation, increasing construction difficulty and jacking risks. Therefore, before jacking construction, it is necessary to assess the large stones, boulders, boulders, and pebbles in the strata and take corresponding pretreatment measures to ensure the safety of subsequent jacking construction.

[0005] Currently, common methods for dealing with large boulders, colossal stones, boulders, and pebbles in strata include slow-speed top grinding, micro-jacking pretreatment, and manual removal within the tunnel. However, all of these methods have significant limitations. Slow-speed top grinding relies on the cutterhead's low-speed abrasion of large boulders to clear obstacles, resulting in severe wear and tear on tools and equipment, and significantly impacting construction efficiency. Micro-jacking pretreatment uses small-diameter rock-breaking pipe jacking machines to pre-break large boulders, requiring multiple equipment installation, debugging, jacking, and retraction operations. This is not only cumbersome, time-consuming, and costly, but also causes repeated disturbances to the strata. Manual removal within the tunnel requires the use of rock splitters or static blasting to manually remove large boulders or boulders inside the tunnel. This is unfavorable for rectangular pipe jacking machines operating within the tunnel, carries high safety risks, and has poor applicability.

[0006] Therefore, how to deal with the problems of low processing efficiency, high wear and tear of cutting tools and equipment, repeated disturbance of the strata and high safety risks in shallow overburden filling strata such as large stones, boulders, pebbles and cobbles during the construction of rectangular pipe jacking is a key technical problem that urgently needs to be solved. Summary of the Invention

[0007] To address the above problems, this invention provides a rectangular pipe jacking machine and slag removal method suitable for complex shallow overburden strata, which can efficiently handle fill strata containing large stones, boulders, pebbles, etc., with minimal ground disturbance, high safety, and minimal wear on equipment.

[0008] The present invention relates to a rectangular pipe jacking machine adapted to complex shallow-cover strata, comprising a housing, a pair of cutterhead assemblies, a spiral excavator, and a belt conveyor. The outer casing includes a front casing and a rear casing arranged front to back. A breast plate is provided inside the front casing, and a pair of cutter head assemblies are arranged side by side on the breast plate. The cutter head assembly includes a drive unit and a cutter head. The drive unit is disposed on the breast plate and is used to drive the cutter head to rotate. The cutter head is located on the front side of the breast plate, and a pair of cutter heads rotate relative to each other. The feed inlet is located below the breast plate, between a pair of cutter heads. The spiral soil discharger is located inside the outer shell and behind the feed inlet, with the feed end of the spiral soil discharger directly facing and matching the feed inlet. The belt conveyor is located below the slag outlet of the spiral auger and is used to receive and transport the slag discharged from the spiral auger.

[0009] A pair of cutter heads are arranged in parallel and stacked. One cutter head has a relief groove on the rear side of its outer end, and the cutting teeth of the outer end of the other cutter head are located in the relief groove. The cutting teeth of the outer ends of the pair of cutter heads are staggered and arranged front and back.

[0010] The outer tube diameter of the spiral soil extractor is 1200-1600mm.

[0011] Inspection holes are provided at the four corners of the breast plate.

[0012] A human cabin is located in the upper middle part of the chest plate.

[0013] A method for removing slag from a rectangular pipe jacking machine used in shallow-covered soil strata containing large rocks includes: When the pipe jacking machine advances normally along the designed axis, a pair of cutterheads cut the soil in front. The large-diameter stones are strongly mixed and improved by the high-power, high-torque cutterheads. After the large stones are squeezed between the cutterheads and the cutterheads, they are crushed into smaller stones. Under the action of the injected modifier, the slag is improved, giving the small-diameter stones a certain buoyancy, which is more conducive to their movement and entry into the auger. Subsequently, the auger discharges the slag simultaneously. After the slag is discharged through the auger outlet, it is transferred by belt conveyor to the slag car and finally transported to the starting shaft for hoisting.

[0014] During the jacking process, slag-modified slurry is injected into the soil chamber and the tunneling face through the pre-set grouting holes of the pipe jacking machine.

[0015] Also includes: When there are large rocks that cannot be handled in the cutterhead cutting blind zone, the jacking operation must be suspended. Then, the strata at the tunnel face are observed through the inspection holes pre-set in the breast plate of the jacking machine. If large rocks are confirmed, a small horizontal drilling rig is used for crushing. After the crushing is completed, the inspection holes are sealed and the jacking machine resumes normal jacking. If the small drilling rig still fails to completely crush the large rocks, and the tunnel face is reinforced with composite thick mortar before opening the chamber due to the shallow overburden conditions, the workers can enter the manhole for effective crushing.

[0016] Also includes: When the cutterhead becomes stuck, first inject composite thick mortar into the working face through the grouting system to fill the voids in the strata, stop water leakage, and maintain the earth pressure balance at the working face. After the working face is stable, the workers enter the working area in front of the pipe jacking machine through the manhole to eliminate the stuck problem. After the problem is resolved, the manhole is sealed and the pipe jacking machine resumes normal jacking.

[0017] During the tunneling process, the rectangular pipe jacking machine of this invention employs a high-power, high-torque cutterhead to slowly cut and compress large-diameter boulders, cobblestones, boulders, and pebbles in the strata. The extrusion force between the cutter and the boulders crushes them into smaller pieces or "trims" the edges of the boulders to allow them to pass through the feed inlet. Subsequently, a soil conditioner is injected into the cutterhead and earth pressure chamber to improve the soil conditions, giving the smaller boulders buoyancy and facilitating their movement into the auger. Then, the small boulders or trimmed boulders are directly transported to a belt conveyor via a large-diameter auger, and from there transferred to muck cars, ultimately being hoisted out at the starting shaft.

[0018] Compared to existing technologies, this invention eliminates the need for pretreatment of the strata before rectangular pipe jacking construction, enabling smooth slag removal by the spiral excavator. This invention significantly improves the adaptability and efficiency of rectangular pipe jacking construction in shallow overburden strata containing large rocks, while also effectively reducing construction safety risks and costs, resulting in substantial overall benefits. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In the drawings, the parts are not necessarily drawn to scale.

[0020] Figure 1 This is a schematic diagram of the structure of the present invention. Figure 2 yes Figure 1 The right view, Figure 3 This is a schematic diagram of the connection structure between the outer casing and the cutter head assembly. Figure 4 This is a schematic diagram of the connection structure between the spiral soil extractor and the belt conveyor. Figure 5 This is a schematic diagram of the connection structure between the outer shell and the cutter head. Figure 6 This is a schematic diagram of the cutter head assembly; In the diagram, 1 is the outer shell, 11 is the front shell, 12 is the rear shell, 13 is the breast plate, 131 is the feed port, 132 is the inspection port, and 133 is the personnel compartment. 2 is the spiral excavator, and 20 is the outer tube. 3 is the belt conveyor, 4 is the drive unit, 5 is the cutter head, and 50 is the clearance groove. Detailed Implementation

[0021] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0022] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "vertical," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0023] like Figure 1-6 As shown, the rectangular pipe jacking machine of the present invention, adapted to complex shallow-cover strata, includes a housing 1, a pair of cutterhead assemblies, a spiral excavator 2, and a belt conveyor 3. The outer casing includes a front housing 11 and a rear housing 12 arranged front to back. A breast plate 13 is provided inside the front housing, and a pair of cutter head assemblies are arranged side by side on the breast plate 13. The cutter head assembly includes a drive unit 4 and a cutter head 5. The drive unit 4 is disposed on the breast plate 113 and is used to drive the cutter head 5 to rotate. The cutter head 5 is located on the front side of the breast plate, and a pair of cutter heads rotate relative to each other. Below the breast plate 13, between a pair of cutter discs, there is a feed inlet 131. The feed inlet is set in the middle, which is an improvement over the previous method of setting one feed inlet on each side. The pair of cutter discs are arranged side by side to perform relative rotation cutting and grinding, which makes it easier to crush large stones into small-diameter stones, or to trim the edges of large stones and then move them to the middle feed inlet under the action of slag soil improvement before being discharged.

[0024] In this field, large stones generally refer to engineering stones with a side length of not less than 15 cm, and are generally square or irregularly angular in shape. In the specific context of this invention, it specifically refers to stones that cannot be directly discharged from the feed inlet 131. This invention does not employ a forced cutting process for such large stones. Instead, it utilizes other smaller stones, boulders, and cobbles in the complex soil layer as a "grinding" medium. Combined with the active driving force of a pair of cutterheads and the soil amendment effect, the large stones are ground and reduced in diameter to fit the size of the feed inlet 131, thus allowing them to be discharged.

[0025] The spiral soil discharger 2 is located inside the outer casing and behind the feed inlet 131. The feed end of the spiral soil discharger is directly opposite to the feed inlet. The belt conveyor is located below the slag outlet of the screw conveyor and is used to receive and transport the slag discharged from the screw conveyor.

[0026] The outer shell is a rigid structure consisting of a front shell and a rear shell connected together; the drive unit adopts a high-torque independent drive design to provide sufficient power for the cutter head cutting and is suitable for cutting operations in large rock fill soil strata.

[0027] A belt conveyor, connected to a spiral discharger, transfers excavated soil from the discharge port of the spiral discharger to a muck truck. It is adaptable to the discharge rate of large-sized spiral dischargers. Compared to the conventional method of directly discharging excavated soil to the muck truck using a spiral discharger, this invention effectively improves the soil removal efficiency and ensures the continuity of pipe jacking construction.

[0028] A pair of cutterheads 5 are arranged in parallel and overlapping configurations. One cutterhead has a clearance groove 50 on its outer rear side, and the cutting teeth of the other cutterhead are located within this groove. The cutting teeth of the outer ends of the two cutterheads are staggered. The cutterheads are installed at the front end of the pipe jacking machine, employing a symmetrical arrangement of the two cutterheads. The cutterheads are arranged parallel to each other in the tunneling direction, improving upon the conventional front-and-back cutterhead configuration. This increases the distance between the cutterhead and the breast plate, providing ample working space for quick maintenance and preventing large rocks from getting stuck, thus affecting the cutterhead's cutting efficiency. The staggered design at the overlapping point of the cutterheads prevents interference during rotation, adapting to different working conditions. It also avoids the excessive extension of the spline shaft connected to the conventional front-mounted cutterhead beyond the breast plate, which is detrimental to the structural integrity. The cutting tools are made of high-strength alloy, improving wear resistance and service life.

[0029] The outer tube 20 of the spiral excavator 2 has a diameter of 1200-1600mm. The spiral excavator adopts a single spiral excavator design and is installed below the personnel cabin. If designed with a large size structure of 1600mm, it has a strong ability to discharge slag and adjust soil pressure. When encountering large-diameter boulders, giant stones, boulders and pebbles, etc., the slag can be discharged directly after the slag is improved without the need for pre-construction pretreatment, effectively solving the problem of easy clogging of conventional size spiral excavators.

[0030] Inspection holes 132 are provided at the four corners of the breast plate. Inspection holes are pre-set at the four corners of the breast plate of the front shell (the blind zone of the cutterhead). When there are large rocks in the blind zone that the cutterhead cannot directly handle, the formation at the working face can be observed through the inspection holes. If it is confirmed that there are large rocks, a small horizontal drilling rig is used to break them up. The obstacle can be cleared without disassembling the equipment, reducing the construction interruption time. A personnel compartment 133 is located in the upper middle part of the breast plate. The personnel compartment is located in the upper middle part of the front shell as a quick inspection and maintenance channel for sudden failures such as cutter head jamming. Operators can directly enter the work area through the personnel compartment to handle the problem, reducing the difficulty of equipment and tool maintenance and the downtime cost.

[0031] A method for removing slag from a rectangular pipe jacking machine used in shallow-covered soil strata containing large rocks includes: During normal jacking along the designed axis, a pair of cutterheads cut the soil in front. The high-power, high-torque cutterheads powerfully mix and improve large-diameter stones, crushing them into smaller pieces under pressure from the cutters. With the injection of a conditioner, the soil is improved, giving the smaller stones buoyancy, making them easier to move and enter the auger. The auger then simultaneously discharges the excavated soil. After exiting the auger's outlet, the excavated soil is transported by belt conveyor to a muck car, and finally hoisted out of the starting shaft.

[0032] The high-torque drive unit rotates the cutterhead at low speed, and the large stones are crushed into smaller pieces by the extrusion force generated between the high-torque cutterhead and the large stones. With the injection of a modifier, the slag is improved, giving the small stones a certain buoyancy, which makes it easier for them to move and enter the spiral excavator smoothly.

[0033] The spiral excavator sucks in small-diameter stones that have been crushed and transported as a whole to the slag outlet. It is then transferred to a slag car via a belt conveyor and subsequently transported to the starting shaft for hoisting. This process eliminates the need for pre-crushing of large stones before pipe jacking, significantly improving construction efficiency while reducing construction risks and costs.

[0034] During the jacking process, slurry is injected into the soil chamber and the tunneling face through the pre-set grouting pipe of the pipe jacking machine. The injection of slag-modified slurry has a dual function: first, it optimizes the fluidity and plasticity of the slag, ensuring smooth slag discharge; second, it increases the buoyancy of the small-diameter stones after they are crushed, assisting them in moving towards the feed inlet area.

[0035] Also includes: When large, unmanageable rocks are present in the cutterhead's blind zone, the jacking operation must be suspended. Subsequently, the strata at the tunnel face are observed through the pre-installed inspection holes on the jacking machine's breast plate. If large rocks are confirmed, a small horizontal drilling rig is used for breakage. After breakage, the inspection holes are sealed, and normal jacking operations resume. If the small drilling rig fails to completely break the large rocks, and given the shallow overburden conditions allow for the injection of thick composite mortar to reinforce the tunnel face before opening the working chamber, personnel can enter the manhole for effective breakage.

[0036] Also includes: When the cutterhead becomes stuck, firstly, composite thick mortar is injected into the working face through the grouting system to fill the voids in the strata, stop water leakage, and maintain earth pressure balance at the working face. After the working face stabilizes, workers enter the working area in front of the pipe jacking machine through the manhole to eliminate the stuck problem. After the problem is resolved, the manhole is sealed off, and the pipe jacking machine resumes normal jacking operation.

[0037] This invention, through innovative structural design and efficient operation process, enables safe, economical, and efficient construction of rectangular pipe jacking in strata containing large-diameter boulders, colossal stones, boulders, and pebbles in shallow overburden. Compared to existing technologies, the core advantages of this invention are reflected in the following aspects: (1) It breaks through the traditional pipe jacking machine's process limitation that large-diameter stones must be pre-treated and crushed to a size that can be passed by a small-diameter spiral discharger before construction. Combining the cutting and extrusion capabilities of the high-torque cutter head with strong mixing and improvement capabilities and the conveying capacity of a large-diameter (e.g., 1600mm) spiral discharger, the slag discharge operation can be completed without pre-treatment, reducing the time spent on the pre-treatment and crushing of large stones. This not only improves construction efficiency but also reduces the construction risks and cost inputs brought about by pre-treatment operations.

[0038] (2) In view of the characteristics of the large rock filling soil strata, the double cutter heads are arranged symmetrically and parallel (with the overlapping part staggered front and back). Combined with high-strength alloy cutter head and high torque independent drive design, on the one hand, the distance between the cutter head and the breast plate is increased, providing sufficient working space and facilitating quick maintenance. On the other hand, the cutting ability of the cutter head is enhanced, and large rocks can also prevent the cutter head from getting stuck, thus extending the service life of the cutter head and reducing maintenance costs.

[0039] (3) By pre-setting inspection holes in the breast plate (cutterhead cutting blind zone) of the front shell of the pipe jacking machine, large rocks in the cutterhead cutting blind zone can be removed without disassembling the equipment during the jacking process, which greatly shortens the downtime for clearing obstacles; the configuration of the personnel cabin serves as a quick maintenance channel in case of sudden failure, which facilitates timely handling of problems such as cutterhead blockage, reduces maintenance difficulty and downtime costs, and effectively ensures the continuity of construction.

[0040] (4) Improve the adaptability of pipe jacking construction. This invention is tailored for rectangular pipe jacking operations in shallow soil strata with large rock fill. It can effectively solve the pain points of traditional pipe jacking machines in such complex strata, such as easy blockage, low efficiency and difficulty in handling faults. It provides a more efficient, safer and more economical equipment manufacturing design and construction scheme for similar geological conditions encountered in urban underground space development.

[0041] Regarding the information disclosed in this case, the following points need to be clarified: (1) The accompanying drawings of the embodiments disclosed in this case only involve the structures involved in the embodiments disclosed in this case; other structures can refer to the general design. (2) Where there is no conflict, the embodiments and features disclosed in this case can be combined with each other to obtain new embodiments; The above are merely specific embodiments disclosed in this case, but the scope of protection of this disclosure is not limited thereto. The scope of protection disclosed in this case shall be determined by the scope of protection of the claims.

Claims

1. A rectangular pipe jacking machine adapted to complex shallow-cover soil strata, characterized in that, Includes a housing, a pair of cutterhead assemblies, a spiral excavator, and a belt conveyor. The outer casing includes a front casing and a rear casing arranged front to back. A breast plate is provided inside the front casing, and a pair of cutter head assemblies are arranged side by side on the breast plate. The cutter head assembly includes a drive unit and a cutter head. The drive unit is disposed on the breast plate and is used to drive the cutter head to rotate. The cutter head is located on the front side of the breast plate, and a pair of cutter heads rotate relative to each other for cutting. A feed inlet is located below the breast plate, between a pair of cutter heads. The spiral soil discharger is located inside the outer shell and behind the feed inlet, with the feed end of the spiral soil discharger directly facing and matching the feed inlet. The belt conveyor is located below the slag outlet of the spiral auger and is used to receive and transport the slag discharged from the spiral auger.

2. A rectangular pipe jacking machine adapted to complex shallow-covered soil strata according to claim 1, characterized in that, A pair of cutter heads are arranged in parallel and stacked. One cutter head has a relief groove on the rear side of its outer end, and the cutting teeth of the outer end of the other cutter head are located in the relief groove. The cutting teeth of the outer ends of the pair of cutter heads are staggered and arranged front and back.

3. A rectangular pipe jacking machine adapted to complex shallow-covered soil strata according to claim 1, characterized in that, The outer tube diameter of the spiral soil extractor is 1200-1600mm.

4. A rectangular pipe jacking machine adapted to complex shallow-covered soil strata according to claim 1, characterized in that, Inspection holes are provided at the four corners of the breast plate.

5. A rectangular pipe jacking machine adapted to complex shallow-covered soil strata according to claim 1, characterized in that, A human cabin is located in the upper middle part of the chest plate.

6. A method for removing slag from a rectangular pipe jacking machine adapted to complex shallow-cover strata as described in any one of claims 1-5, characterized in that, include: When the pipe jacking machine advances normally along the designed axis, a pair of cutterheads cut the soil in front. The large-diameter stones are strongly mixed and improved by the high-power, high-torque cutterheads. After the large stones are squeezed between the cutterheads and the cutterheads, they are crushed into smaller stones. Under the action of the injected modifier, the slag is improved, giving the small-diameter stones buoyancy, which makes it easier for them to move and enter the auger. Then, the auger discharges the slag simultaneously. After the slag is discharged from the auger discharge port, it is transferred to the slag car by belt conveyor and finally transported to the starting shaft for hoisting.

7. A method for removing slag from a rectangular pipe jacking machine adapted to complex shallow-cover strata according to claim 6, characterized in that, During the jacking process, slurry for soil improvement is injected into the soil chamber and the tunneling face through the pre-set grouting holes of the pipe jacking machine.

8. A method for removing slag from a rectangular pipe jacking machine adapted to complex shallow-cover strata according to claim 6, characterized in that, Also includes: When there are large rocks that cannot be handled in the cutterhead cutting blind zone, the jacking operation must be suspended. Then, the strata at the tunnel face are observed through the inspection holes pre-set in the breast plate of the jacking machine. If large rocks are confirmed, a small horizontal drilling rig is used for crushing. After the crushing is completed, the inspection holes are sealed and the jacking machine resumes normal jacking. If the small drilling rig still fails to completely crush the large rocks, and the tunnel face is reinforced with composite thick mortar before opening the chamber due to the shallow overburden conditions, the workers can enter the manhole for effective crushing.

9. A method for removing slag from a rectangular pipe jacking machine adapted to complex shallow-cover strata according to claim 6, characterized in that, Also includes: When the cutterhead becomes stuck, first inject composite thick mortar into the working face through the grouting system to fill the voids in the strata and stop water leakage, thereby maintaining the earth pressure balance at the working face. After the working face is stable, the workers enter the working area in front of the pipe jacking machine through the manhole to eliminate the stuck problem. After the problem is resolved, the manhole is sealed and the pipe jacking machine resumes normal jacking.

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