Rectangular pipe jacking machine steel support platform launching and receiving system and construction method

Abstract

This invention discloses a rectangular pipe jacking machine steel support platform launching and receiving system and construction method, belonging to the field of underground engineering construction technology. The system includes a detachable steel platform erected on a concrete foundation, a guiding and positioning component consisting of a pipe jacking machine telescopic guide block and a tunnel portal guide rail, and a tunnel portal water-stopping component including rubber rings, sponge absorbent rings, and airbags. The construction method covers platform erection, multi-seal installation, automatic guiding entry and exit, and rapid sealing of the tunnel portal using a suspended formwork process. This invention solves the problems of traditional processes, such as the need for separate wells leading to long cycles and high costs, poor guiding accuracy for entry and exit, and difficulties in water-stopping. It features high construction efficiency, precise guidance, and reliable water-stopping, and is suitable for underground space development in densely populated urban areas.

Description

Technical Field

[0001] This invention belongs to the field of underground engineering construction technology, specifically relating to a rectangular pipe jacking machine type steel support platform launching and receiving system and construction method, which is particularly suitable for underground space development projects under narrow site conditions in densely populated urban areas. Background Technology

[0002] Pipe jacking, as an advanced trenchless underground construction technology, has been widely used in underground engineering projects in bustling urban areas due to its minimal impact on the surface environment, lack of traffic obstruction, and low risk of damage to surrounding pipelines. Rectangular pipe jacking, in particular, is frequently used in pedestrian tunnels, subway entrances, and other projects due to its high cross-sectional utilization rate.

[0003] However, the following technical bottlenecks exist in the existing rectangular pipe jacking starting and receiving construction:

[0004] 1. Site and cost constraints: Traditional processes usually require separate excavation and setting of dedicated launching and receiving wells, which not only occupy a large amount of construction site, but also have a long construction period and high civil engineering costs, making it difficult to adapt to the narrow construction environment in the city center.

[0005] 2. Difficulty in guiding control: During the brief process of the pipe jacking machine entering and exiting the tunnel portal, due to the lack of effective external constraints and precise guiding and positioning measures, it is very easy for the axis to deviate, resulting in the machine head "knocking" (sinking) or "lifting" (floating), which not only affects the forming quality, but also brings huge safety hazards.

[0006] 3. Sealing and waterproofing failure: The annular gap between the tunnel portal ring and the outer shell of the pipe jacking machine is a weak point in waterproofing. Existing sealing methods are often ineffective, easily leading to external water and soil seepage, and in severe cases, causing water and sand inrush accidents, threatening the safety of the foundation pit.

[0007] 4. Inefficient post-receipt processing: After the pipe jacking machine receives and lifts the pipe, the sealing of the tunnel entrance at the receiving end is usually done using traditional formwork, which is cumbersome, inefficient, and seriously delays the overall project progress.

[0008] Therefore, there is an urgent need for a new rectangular pipe jacking machine steel support platform launching and receiving system and construction method to solve the problems existing in the current technology. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the prior art and provide a rectangular pipe jacking machine steel support platform receiving system and construction method. By using a reusable steel support platform in the main structure of the station to replace the traditional receiving well, and combining it with a sensor-feedback-based active telescopic guide mechanism for the pipe jacking machine, a multi-port water-stopping structure integrating water absorption and airbags, and a fast sealing process based on corbel supports, a complete and efficient rectangular pipe jacking starting and receiving system is formed.

[0010] To achieve the above technical objectives, the present invention adopts the following technical solution: a rectangular pipe jacking machine steel support platform launching and receiving system and construction method, including:

[0011] The steel platform system is set on a concrete foundation inside the launching shaft or receiving station. The steel platform system includes a supporting steel frame and a steel platform laid on top of the supporting steel frame. Sliding rails and supporting rails are set on the steel platform along the direction of pipe jacking.

[0012] The guiding and positioning assembly includes a guide block assembly mounted on a rectangular pipe jacking machine and a guide rail assembly mounted on a tunnel portal frame. The guide block assembly and the guide rail assembly cooperate to limit the entry and exit trajectory of the pipe jacking machine.

[0013] The portal water-stopping assembly, which is installed at the portal, includes a water-stopping rubber ring, a sponge water-absorbing ring, and an annular protruding airbag arranged sequentially along the tunnel jacking direction.

[0014] Furthermore, the steel platform is a detachable and assembleable structure;

[0015] The sliding rail and the support rail, as well as adjacent support rails, are connected by crossbars; a reinforcing connection assembly is also provided between adjacent support rails, which includes a connecting sleeve, a threaded rod, and a trapezoidal clamping block. The threaded rod passes through the trapezoidal clamping block and is locked by a nut.

[0016] Furthermore, the guide block assembly includes a set of upper guide blocks symmetrically arranged at the top of the rectangular pipe jacking machine and a set of lower guide blocks arranged at the bottom;

[0017] The guide rail assembly includes a set of upper guide rails and a set of lower guide rails correspondingly disposed on the portal frame;

[0018] The rectangular pipe jacking machine is also equipped with a power unit. The upper and lower guide blocks are connected to the push rod of the power unit and can extend and retract relative to the casing of the pipe jacking machine.

[0019] Furthermore, it also includes a guidance control system; the ends of the upper guide block and the lower guide block are equipped with multi-functional sensors, which are connected to the processing system installed on the pipe jacking machine via data lines. The processing system is connected to the power unit via signal, and is used to control the extension and retraction of the push rod according to the sensing signals.

[0020] Furthermore, the sliding track is equipped with a U-shaped slider for supporting the rectangular pipe jacking machine. The U-shaped slider has wing plates on both sides, and jacks for adjusting the attitude of the pipe jacking machine are installed on the wing plates.

[0021] Furthermore, in the portal water-stopping assembly, a limiting block is provided behind the sponge water-absorbing ring for positioning and disassembly of the sponge water-absorbing ring; the annular raised airbag is composed of several annular raised airbag segments, and adjacent annular raised airbag segments are connected by cylindrical inserts and insertion holes.

[0022] A construction method for the rectangular pipe jacking machine steel support platform launching and receiving system as described above includes the following steps:

[0023] Step 1: Soil reinforcement and platform construction: Soil reinforcement is carried out at the starting and receiving ends of the pipe jacking channel, concrete foundations are excavated and constructed, and supporting steel frames and steel platforms are erected on the concrete foundations.

[0024] Step 2, Installation of tunnel portal sealing: Install the tunnel portal water-stop component at the tunnel portal;

[0025] Step 3, Pipe jacking launch or reception: Using the sliding rail on the steel platform as a base, and with the help of the guide and positioning components, the rectangular pipe jacking machine is pushed into or received out of the tunnel.

[0026] Step 4: Tunnel Portal Sealing: After the pipe jacking machine is lifted off, a concrete cover slab is constructed at the tunnel portal, sand is backfilled, and the roof slab is constructed.

[0027] Furthermore, in step three, the control method for the guiding and positioning component is as follows:

[0028] When the rectangular pipe jacking machine enters or exits the tunnel, the multi-functional sensor monitors the displacement of the pipe jacking machine in real time; the processing system controls the power unit according to the monitoring information, driving the upper guide block and the lower guide block to extend forward and slide along the upper guide rail and the lower guide rail respectively;

[0029] Once the pipe jacking machine has fully entered or exited the tunnel, the control guide block retracts into the pre-reserved groove of the pipe jacking machine.

[0030] Furthermore, in step three, the working method of the portal water-stopping component is as follows:

[0031] The slope of the tunnel entrance is used for reverse water sealing; a water-stopping rubber ring is used for the first stage of sealing; and a sponge absorbent ring is used to absorb the seepage water that passes through the water-stopping rubber ring.

[0032] An annular protruding airbag is used for airtight sealing; when the sponge absorbent ring is saturated with water, it is removed and replaced using a limiting block.

[0033] Furthermore, in step four, the construction of the top slab adopts a suspended formwork process:

[0034] A corbel bracket is installed on the inner wall of the receiving station, and a support crossbar is set on the corbel bracket. The bottom formwork of the top slab is tightened by the threaded rod installed on the support crossbar. There is no need to erect a ground scaffold, and the top slab concrete can be poured directly.

[0035] Compared with the prior art, the present invention has the following significant advantages:

[0036] 1. Cost Reduction, Efficiency Improvement, and Space Saving (Platform System): This invention abandons the traditional approach of setting up separate receiving wells, and directly constructs a steel support platform within the main structure of the station using a concrete foundation for receiving. This steel platform integrates dewatering and maintenance functions, and adopts a modular design with bolted connections. After construction, it can be quickly dismantled, cleaned, and reused, significantly shortening the construction period, reducing construction costs, and greatly improving adaptability to narrow construction environments.

[0037] 2. Precise Guidance and Risk Control (Guidance Technology): This invention innovatively employs an active guidance system. Through the cooperation of retractable guide blocks on the pipe jacking machine and guide rails on the tunnel portal frame, combined with real-time feedback control from multi-functional sensors and a processing system, automatic correction and precise positioning of the pipe jacking machine during its entry and exit from the tunnel are achieved. This effectively avoids the pipe jacking machine "nodding" or "raising its head," ensuring the safety and axial accuracy of its entry and exit from the tunnel.

[0038] 3. Highly Efficient Waterproofing with Multiple Guarantees (Sealing Technology): This invention constructs a four-tiered waterproofing defense line consisting of "reverse slope + water-stop rubber + sponge water absorption + annular airbag". In particular, the introduction of a sponge water-absorbing ring to actively absorb seepage water and a modularly splicable annular airbag to provide airtight buffering allows for rapid response even in the event of localized leakage (such as quick replacement of the sponge ring), thereby ensuring the sealing reliability of the tunnel portal throughout the entire construction process and eliminating the potential risks of water and sand inrush.

[0039] 4. Convenient Construction and Rapid Closure (Sealing Technology): For sealing the entrance at the receiving end, this invention adopts an optimized suspended formwork construction process. By installing bracket supports and tightening devices on the inner wall of the station, the fixing and pouring of the top slab formwork can be completed without the need for complex ground scaffolding. Combined with pre-sealed cover plates and backfilling operations, the construction efficiency of the entrance sealing is greatly improved, and the overall project delivery schedule is accelerated. Attached Figure Description

[0040] Figure 1 This is a construction schematic diagram of the rectangular pipe jacking machine's steel support platform launching and receiving system;

[0041] Figure 2 This is a structural schematic diagram of the rectangular pipe jacking machine's steel support platform for initial construction.

[0042] Figure 3 yes Figure 2 An enlarged schematic diagram of part A in the middle;

[0043] Figure 4 This is a structural schematic diagram of the portal waterproofing technology;

[0044] Figure 5 This is a structural schematic diagram of a rectangular pipe jacking machine;

[0045] Figure 6 This is a sectional view of a rectangular pipe jacking machine;

[0046] Figure 7 This is a schematic diagram of the construction structure of the rectangular pipe jacking machine's steel support platform before it exits the receiving well;

[0047] Figure 8 This is a schematic diagram of the construction structure of the rectangular pipe jacking machine's steel support platform after it exits the receiving well;

[0048] Figure 9 This is a construction diagram of the rapid sealing technology for the receiving end portal.

[0049] In the diagram: 1. Dewatering well; 2. Dewatering pipe; 3. Inlet; 4. Pipe jacking machine support track system; 5. Main jacking device; 6. Steel platform; 7. Portal concrete reinforcement ring; 8. Starting shaft inner wall; 9. Mixing reinforcement layer; 10. Weak reinforcement layer; 11. Pipe jacking passage; 12. Portal retaining piles; 13. Station inner wall; 14. Portal; 15. Rectangular pipe jacking machine; 16. Inspection port; 17. Ladder; 18. Supporting steel frame; 19. Concrete foundation; 20. Lower guide rail; 21. Upper guide rail; 22. Support rail; 23. Sliding rail; 24. U-shaped slider; 25. Trapezoidal clamping block; 26. Connecting sleeve; 27. Threaded rod; 28. Wing plate; 29. ​​Jack; 30. 31. Portal frame; 32. Limiting block; 33. Water-stopping rubber ring; 34. Sponge water-absorbing ring; 35. Annular protruding airbag segment; 36. Insertion hole; 37. Columnar insert; 38. Edge; 39. Lower reserved groove; 40. Lower guide block; 41. Upper reserved groove; 42. Push rod; 43. Power unit; 44. Cover; 45. Upper guide block; 46. Wall-breaking disc; 47. Fixing block; 48. Processing system; 49. Input data cable; 50. Output data cable; 51. Connecting rod; 52. Multifunctional sensor; 53. Template; 54. Tightening threaded rod; 55. Top plate; 56. Corbel bracket; 57. Support crossbar; 58. Concrete cover plate; 59. Middle plate; 50. Backfill sand. Detailed Implementation

[0050] The present invention will be further described below with reference to embodiments, wherein traditional construction methods such as welding and installation will not be described in detail. The following description of the embodiments is only for the purpose of helping to understand the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0051] Figure 1 This is a construction schematic diagram of the rectangular pipe jacking machine's steel support platform launching and receiving system; Figure 2 This is a structural schematic diagram of the rectangular pipe jacking machine's steel support platform for initial construction. Figure 3 yes Figure 2 An enlarged schematic diagram of part A in the middle; Figure 4 Schematic diagram of the portal waterproofing technology; Figure 5 This is a structural schematic diagram of a rectangular pipe jacking machine; Figure 6 This is a sectional view of a rectangular pipe jacking machine; Figure 7 This is a schematic diagram of the construction structure of the rectangular pipe jacking machine's steel support platform before it exits the receiving well; Figure 8 This is a schematic diagram of the construction structure of the rectangular pipe jacking machine's steel support platform after it exits the receiving well; Figure 9 This is a construction diagram of the rapid sealing technology for the receiving end portal.

[0052] Example 1: Rectangular pipe jacking machine steel support platform launching and receiving system

[0053] like Figures 1 to 6 As shown, this embodiment provides a rectangular pipe jacking machine steel support platform launching and receiving system. This system is mainly used in urban underground engineering, especially when the construction site is limited and a separate receiving well cannot be set up. It utilizes the internal space of the main structure of the station to carry out the receiving operation of the pipe jacking machine.

[0054] The system mainly includes a steel platform system, a guide and positioning component, a tunnel portal water-stopping component, and a supporting structure for the pipe jacking machine body.

[0055] 1. Overall Environment and Infrastructure

[0056] The construction environment typically includes the inner wall 8 of the launching shaft and the inner wall 13 of the receiving station. A weak reinforcement layer 10 is provided in the soil around the pipe jacking tunnel 11, and a mixing reinforcement layer 9 is provided in the soil near the portal 14. To strengthen the portal structure, portal concrete reinforcement rings 7 are constructed at the launching and receiving portals respectively, and portal retaining piles 12 are constructed behind the portals.

[0057] 2. Steel platform system

[0058] This invention abandons the traditional concrete receiving well bottom slab and adopts a recyclable steel assembly structure. First, a retainable concrete foundation 19 is constructed at the bottom after the weak reinforcement layer 10 is excavated. Multiple sets of supporting steel frames 18 are erected on the concrete foundation 19. A steel platform 6 is laid above the supporting steel frames 18. For convenient drainage and personnel maintenance during construction, the steel platform 6 has a water inlet 3 and an inspection port 16. The water inlet 3 is connected to a dewatering pipe 2, which extends to the dewatering well 1 below to drain accumulated water from the foundation pit. A ladder 17 is installed below the inspection port 16 to facilitate access for construction personnel to the interior of the supporting steel frames 18 for maintenance.

[0059] The surface of the steel platform 6 is provided with sliding rails 23 and support rails 22 along the direction of pipe jacking.

[0060] Connection Structure: To achieve efficient assembly and disassembly, a reinforced connection assembly is provided between adjacent support rails 22. Specifically, this assembly includes a connecting sleeve 26, a threaded rod 27, and a trapezoidal clamping block 25. One end of the threaded rod 27 is screwed and fixed inside the connecting sleeve 26, and the other end passes through the trapezoidal clamping block 25, which is then tightened and fixed by tightening a nut. This structure ensures the overall rigidity and stability of the platform.

[0061] Sliding support: A U-shaped slider 24 is provided on the sliding track 23 to support the rectangular pipe jacking machine 15. Wing plates 28 are welded to both sides of the U-shaped slider 24, and jacks 29 are installed on the wing plates 28. The top of the jacks 29 abuts against the bottom of the rectangular pipe jacking machine 15 for fine adjustment of the vertical attitude of the pipe jacking machine.

[0062] 3. Guiding and positioning components

[0063] To address the issue of the pipe jacking machine "bumping" or "lifting" when entering and exiting the tunnel, this system is designed with an active guiding structure.

[0064] Machine Body: The front end of the rectangular pipe jacking machine 15 is equipped with a wall-breaking disc 45. An upper pre-reserved groove 40 is located above the machine body, and a lower pre-reserved groove 38 is located below. The surfaces of the grooves can be covered by covers 43 for dust prevention. A set of upper guide blocks 44 is installed in the upper pre-reserved groove 40, and a set of lower guide blocks 39 is installed in the lower pre-reserved groove 38. These guide blocks are all connected to a power device 42 (such as a hydraulic cylinder or electric push rod). The power device 42 pushes the guide blocks forward or backward via a push rod 41.

[0065] Portal section: A portal frame 30 is installed at the portal 14, and the portal frame 30 has an outwardly extending body 37. A set of upper guide rails 21 and lower guide rails 20 are installed on the inner side of the body 37.

[0066] Intelligent Control System: To achieve automated and precise guidance, multi-functional sensors 51 (such as displacement sensors and pressure sensors) are installed at the ends of both the upper guide block 44 and the lower guide block 39. The multi-functional sensors 51 are connected to a processing system 47 mounted on a fixed block 46 on the back of the pipe jacking machine via a data input line 48. The fixed block 46 is connected to the pipe jacking machine body via a connecting rod 50. The processing system 47 sends commands to the power unit 42 via an output data line 49.

[0067] 4. Waterstop components for tunnel entrances

[0068] like Figure 4 As shown, in order to prevent soil erosion, the present invention employs a multi-layer sealing structure.

[0069] Reverse water stop: The body 37 of the portal frame 30 is provided with a certain slope to form a physical reverse water stop structure.

[0070] The first line of defense: A water-stop rubber ring 32 is installed close to the rear of the lower guide rail 20 and the upper guide rail 21.

[0071] The second line of defense: A sponge absorbent ring 33 is installed behind the water-stop rubber ring 32. The sponge absorbent ring 33 is positioned and installed by a limiting block 31. The design of the limiting block 31 allows the sponge absorbent ring 33 to be quickly removed and replaced with a new sponge ring after it has absorbed water to saturation.

[0072] The third line of defense: A ring-shaped protruding airbag is located behind the sponge absorbent ring 33. This airbag is composed of several ring-shaped protruding airbag segments 34 spliced ​​together. Adjacent segments are quickly connected by inserting cylindrical blocks 36 into the insertion holes 35. This modular design facilitates installation in confined spaces.

[0073] Example 2: Construction Method for Launching and Receiving Rectangular Pipe Jacking Machine Steel Support Platform

[0074] Based on the system described in Embodiment 1, this embodiment details its construction method, including the following steps:

[0075] Step 1: Soil reinforcement and platform construction at the initial receiving section

[0076] Soil reinforcement: At the starting and receiving ends of the pipe jacking tunnel 11, the soil is reinforced by mixing piles to form a mixing reinforcement layer 9. Concrete reinforcement rings 7 are constructed at the inner wall 8 of the starting shaft and the inner wall 13 of the station, and portal retaining piles 12 are constructed behind the portal.

[0077] Foundation construction: Excavate the weak reinforcement layer 10 to the design elevation, and pour the concrete foundation 19.

[0078] Platform erection: A supporting steel frame 18 is erected on the concrete foundation 19, a steel platform 6 is laid, and sliding rails 23 and supporting rails 22 are installed. The rail system is locked by rotating the connecting sleeve 26 and the nut, using trapezoidal locking blocks 25.

[0079] Dewatering arrangement: Connect the dewatering pipe 2 to the water inlet 3 to ensure that the groundwater level is lower than the construction surface.

[0080] Step 2: Installation of the portal seal

[0081] Before the rectangular pipe jacking machine 15 arrives, a water-stop rubber ring 32, a sponge water-absorbing ring 33, and an annular protruding airbag segment 34 are installed sequentially at the receiving end portal 14. The position of the sponge water-absorbing ring 33 is fixed using a limiting block 31.

[0082] Step 3: Pipe jacking machine guidance, launching, and receiving construction

[0083] This step uses the receiving process as an example (the sending process is similar, only in the opposite direction):

[0084] Piles breaking: Before the rectangular pipe jacking machine 15 reaches the receiving tunnel portal, the portal retaining piles 12 are broken.

[0085] Extending guide blocks: When the multi-functional sensor 51 detects that the pipe jacking machine has reached a preset distance from the tunnel entrance, the signal is transmitted to the processing system 47 via the input data line 48. The processing system 47 issues a command to control the power unit 42 to work via the output data line 49. The push rod 41 pushes the upper guide block 44 and the lower guide block 39 to extend forward from the reserved groove.

[0086] Guided entry: The main jacking device 5 propels the rectangular pipe jacking machine 15 forward. The extended upper guide block 44 and lower guide block 39 slide into the upper guide rail 21 and lower guide rail 20 at the tunnel entrance, respectively, which restricts the up and down swing of the pipe jacking machine and prevents it from "bumping".

[0087] Sliding and Attitude Adjustment: After the tunnel boring machine (TBM) head enters the tunnel portal, the bottom of the TBM contacts the U-shaped slider 24 on the steel platform 6. At this time, the operator can fine-tune the height of the TBM head by controlling the jacks 29 on the wing plates 28.

[0088] Retraction: After the rectangular pipe jacking machine 15 is fully mounted on the steel platform 6 and supported by the pipe jacking machine support track system 4, the power unit 42 reverses its operation and retracts the guide block into the upper reserved groove 40 and the lower reserved groove 38.

[0089] Water-stopping function: During tunneling, if a small amount of groundwater overflows the water-stopping rubber ring 32, it will be absorbed by the sponge water-absorbing ring 33; if the water volume is too large, the annular protruding airbag segment 34 provides a final seal. Construction personnel can quickly replace the sponge using the limiting block 31 according to the saturation level of the sponge water-absorbing ring 33.

[0090] Step 4: Sealing the tunnel entrance and restoring the structure

[0091] like Figure 9 As shown, after the rectangular pipe jacking machine 15 is lifted away from the receiving station, the tunnel portal is sealed:

[0092] Sealing and backfilling: Concrete cover slab 57 is constructed at the original portal location for initial sealing. Steel platform 6 and supporting steel frame 18 are removed, but concrete foundation 19 is retained. Sand 59 is backfilled above concrete foundation 19 to the bottom elevation of the middle slab.

[0093] Construction of intermediate slab: The intermediate slab 58 is constructed above the backfill sand 59 using conventional methods.

[0094] Construction of the roof slab using suspended formwork: For the construction of the roof slab 54, full-span scaffolding is not used. Install corbel supports 55 above the station inner wall 13. Erect supporting crossbars 56 on the corbel supports 55. Install threaded clamping rods 53 on the supporting crossbars 56. Place the formwork 52 (bottom formwork) of the roof slab 54 into position, and rotate the threaded clamping rods 53 to tighten the formwork 52 upwards.

[0095] Pouring: After tying the reinforcing bars, pour 54 cubic meters of concrete for the top slab to complete the structural closure.

[0096] Through the description of the above embodiments, those skilled in the art can clearly understand how the present invention achieves safe and efficient launching and receiving of rectangular jacking pipes in narrow spaces through steel platforms, active guidance, multiple water-stopping and hanging mold sealing technologies.

Claims

1. A launching and receiving system for a rectangular pipe jacking machine steel support platform, characterized in that, include: A steel platform system is set on a concrete foundation (19) inside the launching shaft or receiving station. The steel platform system includes a supporting steel frame (18) and a steel platform (6) laid on the supporting steel frame (18). The steel platform (6) is provided with a sliding track (23) and a supporting track (22) along the pipe jacking direction. The guiding and positioning assembly includes a guide block assembly mounted on the rectangular pipe jacking machine (15) and a guide rail assembly mounted on the tunnel portal frame (30). The guide block assembly and the guide rail assembly cooperate to restrict the entry and exit trajectory of the pipe jacking machine. The guide block assembly includes a set of upper guide blocks (44) symmetrically mounted on the top of the rectangular pipe jacking machine (15) and a set of lower guide blocks (39) mounted on the bottom. The guide rail assembly includes a set of upper guide rails (21) and lower guide rails (20) correspondingly mounted on the tunnel portal frame (30) along the body (37). The rectangular pipe jacking machine (15) is also equipped with a power unit (42). The upper guide blocks (44) and lower guide blocks (39) are connected to the push rod (41) of the power unit (42) and can extend and retract relative to the casing of the pipe jacking machine. The portal water-stopping assembly, which is installed at the portal (14), includes a water-stopping rubber ring (32), a sponge water-absorbing ring (33), and an annular protruding airbag arranged sequentially along the tunnel jacking direction.

2. The rectangular pipe jacking machine steel support platform launching and receiving system according to claim 1, characterized in that, The steel platform (6) is a detachable assembly structure; The sliding rail (23) and the support rail (22) are connected by a crossbar, as are adjacent support rails (22); a reinforcing connection assembly is also provided between adjacent support rails (22), the reinforcing connection assembly including a connecting sleeve (26), a threaded rod (27) and a trapezoidal clamping block (25), the threaded rod (27) passes through the trapezoidal clamping block (25) and is locked by a nut.

3. The rectangular pipe jacking machine steel support platform launching and receiving system according to claim 1, characterized in that, It also includes a guide control system; the ends of the upper guide block (44) and the lower guide block (39) are provided with multi-functional sensors (51), the multi-functional sensors (51) are connected to the processing system (47) set on the pipe jacking machine through a data line, the processing system (47) is connected to the power device (42) by signal, and is used to control the extension and retraction of the push rod (41) according to the sensing signal.

4. The rectangular pipe jacking machine steel support platform launching and receiving system according to claim 1, characterized in that, The sliding track (23) is provided with a U-shaped slider (24) for supporting the rectangular pipe jacking machine (15). The U-shaped slider (24) has wing plates (28) on both sides, and jacks (29) for adjusting the attitude of the pipe jacking machine are installed on the wing plates (28).

5. The rectangular pipe jacking machine steel support platform launching and receiving system according to claim 1, characterized in that, In the portal water-stopping assembly, a limiting block (31) is provided behind the sponge water-absorbing ring (33) for positioning and disassembling the sponge water-absorbing ring (33); the annular protruding airbag is composed of several annular protruding airbag segments (34), and adjacent annular protruding airbag segments (34) are connected by a cylindrical insert (36) and an insertion hole (35).

6. A construction method for a rectangular pipe jacking machine steel support platform launching and receiving system as described in any one of claims 1 to 5, characterized in that, Includes the following steps: Step 1, Soil reinforcement and platform construction: Soil reinforcement is carried out at the starting and receiving ends of the pipe jacking channel (11), and a concrete foundation (19) is excavated and constructed. The supporting steel frame (18) and steel platform (6) are erected on the concrete foundation (19). Step 2, Installation of the tunnel portal sealing: Install the tunnel portal water-stop assembly at the tunnel portal (14); Step 3, Pipe jacking start or reception: Using the sliding rail (23) on the steel platform (6) as a base, and in conjunction with the guide positioning component, push the rectangular pipe jacking machine (15) into or receive the exit gate (14). Step 4, Tunnel Portal Sealing: After the pipe jacking machine is lifted off, a concrete cover plate (57) is constructed at the tunnel portal, sand (59) is backfilled, and the top plate (54) is constructed.

7. The construction method according to claim 6, characterized in that, In step three, the control method for the guiding and positioning component is as follows: When the rectangular pipe jacking machine (15) enters or exits the tunnel, the multi-functional sensor (51) monitors the displacement of the pipe jacking machine in real time; the processing system (47) controls the power unit (42) according to the monitoring information, driving the upper guide block (44) and the lower guide block (39) to extend forward and slide along the upper guide rail (21) and the lower guide rail (20) respectively; Once the pipe jacking machine has fully entered or exited the tunnel, the control guide block retracts into the pre-reserved groove of the pipe jacking machine.

8. The construction method according to claim 6, characterized in that, In step three, the working method of the portal water-stopping assembly is as follows: The slope of the tunnel entrance (37) is used for reverse water sealing; the water-stopping rubber ring (32) is used for the first-level sealing; and the sponge water-absorbing ring (33) is used to absorb the seepage water that passes through the water-stopping rubber ring (32). An annular protruding airbag is used for airtight sealing; when the sponge water-absorbing ring (33) is saturated with water, it is removed and replaced by a limiting block (31).

9. The construction method according to claim 6, characterized in that, In step four, the construction of the top slab (54) adopts the suspended formwork process: Install brackets (55) on the inner wall (13) of the receiving station, set up support crossbars (56) on the brackets (55), and use the tightening threaded rods (53) installed on the support crossbars (56) to tighten the bottom template (52) of the top plate (54), without the need to erect ground scaffolding, and directly pour the top plate concrete.

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