Long-distance suspension protection structure and construction method for concrete pipes in foundation pits

Abstract

The present invention discloses a long-distance suspension protection structure and construction protection method for concrete pipes during foundation pit excavation, and belongs to the technical field of pipeline suspension protection. The suspension protection structure includes a suspension main beam and retaining piles arranged on both sides of the foundation pit. The suspension main beam arranged along the pipeline direction is evenly spaced and distributed with suspension points. Each suspension main beam arranged along the axis of the foundation pit is provided with a suspension point. A crown beam is provided on the top surface of the retaining pile. The suspension main beam spans the foundation pit and is placed on the top surface of the crown beam. The two sides of the bottom of the suspension main beam are anchored into the crown beam through suspension supports. The concrete pipe section between the two retaining piles is covered with a steel casing. A steel wire rope is suspended on the suspension main beam's suspension point. The two ends of the steel wire rope are connected to the suspension fixture suspended under the steel casing through a basket bolt. In-situ suspension protection can be carried out without relocating the pipeline, which can effectively avoid the risk of pipeline damage caused by soil settlement, and at the same time has the advantages of being able to fully utilize the working space and being easy to construct.

Description

Technical Field

[0001] The invention relates to the technical field of pipeline suspension protection, and in particular to a long-distance suspension protection structure and a construction method for a concrete pipeline in a foundation pit. Background Art

[0002] The deep foundation pit construction of subway projects will inevitably have a great impact on the existing municipal pipelines such as rainwater, sewage, electricity, communications, water supply, heat, gas, etc., and bring inconvenience to the layout of the original planned and under-construction pipelines. If the pipelines are not properly protected, they will often cause cracking and damage to the pipelines, and even cause catastrophic consequences such as ground collapse, traffic interruption, casualties, etc., causing huge economic losses and serious social impacts. The issue of pipeline relocation and how to protect existing pipelines has become one of the difficult problems in subway construction.

[0003] The main forms of underground pipeline protection during the subway construction phase include: in-situ protection, suspension protection, broken pipe suspension protection (mainly for communication pipelines and power pipelines), temporary relocation protection, etc. For large-diameter tap water pipes, rainwater and sewage pipelines, or pipelines that are closely related to the normal life of residents and cannot be temporarily disconnected, or the cost of pipeline relocation is too high, in-situ protection measures have to be taken. Since the in-situ suspension method can effectively avoid the risk of pipeline damage due to soil settlement, and at the same time has the advantages of being able to fully utilize the working space and easy to construct, it has become the first choice for in-situ protection of large-diameter pipelines during underground engineering construction. At present, for large-diameter rigid concrete pipelines, they have a large self-weight and poor ability to resist deformation, and the joints are prone to breakage and damage, so the difficulty of protection will also increase significantly. Summary of the invention

[0004] The purpose of the present invention is to provide a long-distance suspension protection structure and a protection method for concrete pipes in a foundation pit, which has the advantages of high construction efficiency, strong safety, small impact on the surroundings, shortened construction period and reduced costs.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] The long-distance suspension protection structure of the concrete pipe in the foundation pit includes a suspension main beam arranged along the pipeline direction and a plurality of suspension main beams equidistantly arranged along the axial direction of the foundation pit, and the suspension main beams arranged along the pipeline direction are equidistantly distributed with group suspension points, and each suspension main beam arranged along the axial direction of the foundation pit is provided with a group suspension point, and also includes retaining piles arranged on both sides of the foundation pit, and the top surface of the retaining piles is provided with a crown beam, and the suspension main beam spans the foundation pit and is placed on the top surface of the crown beam. The two sides of the bottom of the suspension main beam are anchored into the crown beam through suspension supports, and the concrete pipe section between the two retaining piles is covered with a steel casing, and rubber rings are provided at the interfaces between the two ends of the steel casing and the concrete pipe, and the outside of the interface is sealed by concrete, and a steel wire rope is suspended on the group suspension point of the suspension main beam, and the two ends of the steel wire rope are connected to the suspension fixture suspended under the steel casing through basket bolts, and the suspension fixture is provided with a supporting part in contact with the lower outer edge of the steel casing.

[0007] Preferably, a flexible belt is wrapped around the outer periphery of the steel casing in contact with the steel wire rope, and the flexible belt is a rubber belt, which is wrapped around the steel casing for at least two turns, so as to prevent the steel wire rope from breaking due to friction caused by contact between the steel wire rope and the steel casing.

[0008] Furthermore, Ω-shaped limiters are symmetrically provided at the vertical position where the flexible belt contacts the steel wire rope, in order to prevent the suspension steel wire rope from sliding and shifting.

[0009] When the steel wire rope is used for suspension, when the pipeline is subjected to external force, the above-mentioned structural arrangement can avoid lateral displacement of the entire suspension system and ensure the safety of the pipeline receiving interface.

[0010] Preferably, the suspension fixture is a C-shaped structure opening to the side, and an inclined surface is provided on the inner side of the bottom of the C-shaped structure. The inclined surface and the inner wall of the C-shaped structure form a supporting portion, and the concrete pipe slides into the supporting portion along the inclined surface. During suspension, both ends of the wire rope are connected to the top surface of the suspension fixture with the C-shaped structure through basket bolts.

[0011] The setting of the above-mentioned inclined surface can adapt to the diameters of various pipelines. The cooperation of the C-shaped structure and the inclined surface can make the pipeline easily enter the supporting part, which has the advantage of easy construction.

[0012] Furthermore, in order to maintain a safe distance, the spacing between the steel wire ropes during suspension is 1000mm, and reflective stickers are wrapped around both ends of the steel wire ropes to improve night visibility.

[0013] Preferably, the suspended main beam is a Bailey beam, distribution beams are arranged on the Bailey beam at equal longitudinal intervals, a bridge deck is provided on the distribution beams arranged at equal longitudinal intervals, the bridge deck has the same elevation as the ground, and the distribution beam is an I-beam and the upper chord of the Bailey beam is limited by a clamping plate.

[0014] Furthermore, the Bailey piece on the Bailey beam is connected to the crown beam through a suspension support, and the suspension support includes an embedded steel plate, an embedded bolt rod assembly and a U-shaped cover plate. The embedded steel plate is anchored at a corresponding position on the crown beam, and the bottom end of the Bailey piece is inserted into the U-shaped cover plate and contacts the embedded steel plate. The two ends of the U-shaped cover plate are fastened to the embedded steel plate through the embedded bolt rod assembly; a retaining wall is also provided on the top surface of the crown beam, and the two ends of the Bailey beam are against the retaining wall, and a concrete section is added between the retaining wall and the crown beam.

[0015] Furthermore, the bolt rod embedded assembly is a group of symmetrically arranged L-shaped structures, the extended part of the L-shaped structure faces outward, and the bottom end thereof is anchored in the crown beam.

[0016] As a preferred technical solution of the present invention, a long-distance suspension protection structure and construction protection method for a concrete pipe in a foundation pit comprises the following steps:

[0017] Step 1) The concrete pipes are divided into rainwater pipes and sewage pipes. New rainwater inspection wells and sewage inspection wells are built outside the foundation pit by manual excavation. After the foundation pit is excavated to the bottom elevation of the new inspection well, the upstream and downstream inspection wells are blocked and drainage blocking measures are taken;

[0018] Step 2) When excavating to the elevation of the rainwater pipe, connect the reinforced concrete flat pipe to the inspection well, and connect the steel casing to the rainwater concrete pipe above the foundation pit. The interface between the rainwater pipe and the rainwater inspection well, and the interface between the steel casing and the rainwater pipe are all sealed with concrete, and a rubber ring is provided at the interface between the steel casing and the rainwater pipe;

[0019] Step 3) After the Bailey beam construction is completed, the rainwater pipe is suspended for protection. A rainwater pipe suspension main beam is laid out along the pipeline direction. A group of suspension points is set every 1m on the rainwater pipe suspension main beam. The rainwater pipe is placed on the supporting part of the suspension fixture under the multiple groups of suspension points. The basket bolts are adjusted and the steel wire rope is tightened so that the pipeline is in a suspended state and at the same elevation, thereby completing the rainwater pipe suspension protection;

[0020] Step 4) Continue to dig downward to the elevation of the sewage pipe, and set the steel casing for the sewage pipe in the same way as step 2), and place the sewage pipe obliquely between the foundation pits, and then perform suspension protection construction on the sewage pipe, and arrange several sewage pipe suspension main beams along the axial direction of the foundation pit, and each sewage pipe suspension main beam is provided with a group suspension point, and the supporting part of the suspension fixture under the multiple group suspension points of the several sewage pipe suspension main beams on the sewage pipe is adjusted by tightening the wire rope so that the pipeline is in a suspended state and at the same elevation, and the sewage pipe suspension protection is completed;

[0021] Step 5) After the rainwater pipe suspension protection and sewage pipe suspension protection construction are completed, the temporary steel temporary bridge 100 is constructed, and the distribution beam and the bridge deck are laid on the Bailey beam in sequence. When the foundation pit construction is completed and the earth is backfilled to the bottom of the rainwater pipe and sewage pipeline, the upstream and downstream of the rainwater pipe and sewage pipe are blocked, the temporary steel casing is removed, and the protection construction of the rainwater pipe and sewage pipe is completed according to the design concrete pipe requirements.

[0022] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The suspension main beam in the suspension protection structure of the present invention can use double-jointed I-beams as temporary suspension main beams, or can use Bailey beams as suspension main beams. There are various types of concrete pipes in the foundation pit under the auxiliary structure of the subway station, and suspension protection can be carried out in a targeted manner for different pipes. For the obliquely arranged concrete pipes, multiple suspension main beams can be erected, and each main beam is provided with a suspension point, so that the layout method is more reasonable; at the same time, the structure of the suspension fixture can adapt to the diameter of the pipe, and the combination of the C-shaped structure and the inclined surface can make the pipeline easily enter the supporting part, which has the advantage of easy construction.

[0024] (2) The construction protection method enables in-situ suspension protection without relocating the pipeline, which can effectively avoid the risk of pipeline damage due to soil settlement. It also has the advantage of being able to fully utilize the working space, greatly improving the construction efficiency of the subway station and saving construction time and costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic diagram of a suspension protection structure of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of the suspension fixture suspending the pipeline of the present invention;

[0027] Figure 3 This is a schematic diagram of the structure of the distribution beam and the clamping plate of the present invention;

[0028] Figure 4 It is a side view structural schematic diagram of the connection node between the steel casing and the steel wire rope of the present invention;

[0029] Figure 5 It is a schematic diagram of the top view of the connection node between the steel casing and the steel wire rope of the present invention;

[0030] Figure 6 It is a structural schematic diagram of the suspension support of the present invention;

[0031] Figure 7 This is a layout diagram of the suspended main beam of Example 1 of the present invention;

[0032] Figure 8This is a layout diagram of laying a bridge deck on a suspended main beam according to Embodiment 1 of the present invention;

[0033] In the figure: 1-retaining wall, 2-crown beam, 3-guard pile, 4-steel casing, 5-steel wire rope, 50-flexible belt, 51-Ω type limiter, 6-suspension fixture, 60-inclined surface, 7-concrete, 8-rubber ring, 9-inspection well, 10-Bailey beam, 101-Bailey plate, 11-card, 12-bridge deck, 13-distribution beam, 14-sewage pipe suspension main beam, 15-rainwater pipe suspension main beam, 16-sewage pipe, 17-rainwater pipe, 18-basket bolt, 19-concrete pipe, 20-concrete section, 30-foundation pit, 31-axial direction, 70-U-type cover plate, 71-embedded steel plate, 72-bolt rod embedded assembly, 100-temporary steel bridge. DETAILED DESCRIPTION

[0034] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are described with reference to the accompanying drawings.

[0035] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings. The present application is applied to a special construction project for excavation of foundation pits for auxiliary structures of Chengdu subway stations:

[0036] Construction background: Figure 1 Affected by the temporary steel bridge 100, the main beam for the rainwater and sewage pipe suspension protection cannot be arranged along the direction of the suspension pipeline. Combined with the actual situation on site, the suspension main beam spans the station auxiliary structure and is placed on the top surface of the crown beam. Both sides are anchored into the crown beam 800mm. A Φ12.5mm steel wire rope (GB1102-74 / rope 6×19 strands) is hung on the suspension main beam. Both ends of the steel wire rope are fastened with JW3310 (P grade) type basket bolts. The steel bridge is 9.12m long and 22.6m wide. It is composed of Bailey beam 10, distribution beam 13 and bridge deck 12. The Bailey beam 10 is composed of Bailey sheet 101, latch and 900 type Bailey support frame.

[0037] Example 1

[0038] like Figure 1As shown, the long-distance suspension protection structure of the concrete pipe in the foundation pit includes a suspension main beam arranged along the pipeline direction and a plurality of suspension main beams equidistantly arranged along the axial direction of the foundation pit, the suspension main beams arranged along the pipeline direction are equidistantly distributed with group suspension points, each suspension main beam arranged along the axial direction of the foundation pit is provided with a group suspension point, and also includes retaining piles 3 arranged on both sides of the foundation pit, the top surface of the retaining piles 3 is provided with a crown beam 2, the suspension main beam spans over the foundation pit and is placed on the top surface of the crown beam 2, and the suspension The two sides of the bottom of the main beam are anchored into the crown beam 2 through the suspension support, and the concrete pipe 19 section between the two retaining piles 3 is covered with a steel casing 4. Rubber rings 8 are provided at the interfaces between the two ends of the steel casing 4 and the concrete pipe 19. The outside of the interface is sealed with concrete 7. A steel wire rope 5 is suspended on the assembly point of the suspended main beam. The two ends of the steel wire rope are connected to the suspension fixture 6 suspended under the steel casing 4 through the basket bolts 18. The suspension fixture 6 is provided with a supporting part that contacts the lower outer edge of the steel casing 4.

[0039] like Figure 4 and Figure 5 As shown, a flexible belt 50 is wrapped around the outer periphery of the steel casing 4 in contact with the steel wire rope 5. The flexible belt 50 is a rubber belt, which is wrapped around the steel casing 4 for at least two turns to prevent the steel wire rope 5 from breaking due to friction caused by contact with the steel casing 4.

[0040] like Figure 4 and Figure 5 As shown, in order to prevent the suspension wire rope 5 from sliding and shifting, an Ω-shaped limiter 51 is symmetrically provided at the vertical position where the flexible belt 50 contacts the wire rope 5. When the wire rope 5 is suspended and the pipeline is subjected to external force, the above-mentioned structural setting can avoid the lateral displacement of the entire suspension system and ensure the safety of the pipeline bearing interface.

[0041] like Figure 2 As shown, the suspension fixture 6 is a C-shaped structure opening to the side, and an inclined surface 60 is provided on the inner side of the bottom of the C-shaped structure. The inclined surface and the inner wall of the C-shaped structure form a supporting portion, and the concrete pipe 19 slides into the supporting portion along the inclined surface 60. During suspension, both ends of the wire rope 5 are connected to the top surface of the suspension fixture 6 with a C-shaped structure through basket bolts 18.

[0042] The arrangement of the inclined surface 60 can adapt to the diameters of various pipelines. The cooperation of the C-shaped structure and the inclined surface 60 can make the pipeline easily enter the supporting part, which has the advantage of easy construction.

[0043] like Figure 2 As shown, in order to maintain a safe distance, the spacing between the steel wire ropes 5 during suspension is 1000 mm, and reflective stickers are wrapped around both ends of the steel wire ropes 5 to improve nighttime visibility.

[0044] like Figure 3As shown, the suspended main beam is a Bailey beam 10, on which distribution beams 13 are arranged at equal longitudinal intervals, and a bridge deck 12 is provided on the distribution beams 13 arranged at equal longitudinal intervals. The bridge deck 12 has the same elevation as the ground. The distribution beam 13 is an I-beam and the upper chord of the Bailey beam 10 is limited by a clamping plate 11 to ensure the integrity of the Bailey beam 10.

[0045] Construction of Bailey beam 10: The main beam adopts 1.5m×3m Bailey plate 101, and the Bailey plate 101 is spliced ​​and extended on a flat ground by Bailey pins. Since the width of foundation pit 30 is 7.7m, the extension length of Bailey plate 101 is 9m.

[0046] like Figure 6 As shown, in order to ensure the stability of the Bailey beam 10, a suspension support is added as a fixing part of the Bailey beam 10. The Bailey piece 101 on the Bailey beam 10 is connected to the crown beam 2 through the suspension support, and the suspension support includes an embedded steel plate 71, a bolt rod embedded assembly 72 and a U-shaped cover plate 70. The embedded steel plate 71 is anchored at a corresponding position on the crown beam 2, and the bottom end of the Bailey piece 101 is inserted into the U-shaped cover plate 70 and contacts the embedded steel plate 71. The two ends of the U-shaped cover plate 70 are fastened to the embedded steel plate 71 through the bolt rod embedded assembly 72; a retaining wall is also provided on the top surface of the crown beam 2, and the two ends of the Bailey beam 10 are against the retaining wall. A concrete section 20 is added between the retaining wall and the crown beam 2.

[0047] Reasons for adding concrete section 20: Bailey beam 10 is installed on crown beam 2, and the temporary bridge height is 1.72m. Considering that the bridge deck elevation is the same as the ground elevation, the crown beam 2 needs to determine the additional concrete height h according to the ground elevation, and the net distance between the retaining walls is 8.9m, which cannot meet the Bailey bridge length of 9.12m. Therefore, the retaining wall needs to be moved outward by 150mm, and the width of crown beam 2 needs to be expanded at the same time (that is, the original crown beam 2 needs to be increased by 173mm in height and 150mm in width) to ensure that the net distance between the retaining walls meets the length of the temporary steel temporary bridge 100.

[0048] Construction of retaining wall: Pipeline suspension protection outside foundation pit 30 Before backfilling foundation pit 30, a concrete retaining wall needs to be set outside foundation pit 30. The concrete retaining wall is cast in situ with C30 concrete, HPB300 and HPB400 steel bars, and the retaining wall width is 300mm. The retaining wall is located in the middle of the retaining piles and is connected to the bored pile reinforcement. The bottom of the wall is 20mm to the bottom of the sewage pipe 16, and the top of the wall is 200mm above the ground. The retaining wall is cast in two sections. When the trench is excavated to the bottom of the sewage pipe 16, the first section of the retaining wall is cast from the bottom of the sewage pipe 16 to the bottom of the rainwater pipe 17. After the construction of the suspension protection of the rainwater pipe 17 is completed, the second section of the retaining wall from the bottom of the rainwater pipe 17 to 200mm above the ground will be constructed.

[0049] like Figure 6As shown, the bolt rod embedded assembly 72 is a set of symmetrically arranged L-shaped structures, with the extended part of the L-shaped structure facing outward and the bottom end thereof anchored in the crown beam 2.

[0050] Example 2

[0051] like Figure 7 and Figure 8 As shown, the construction protection method of the long-distance suspension protection structure of the concrete pipe 19 during the excavation of the foundation pit 30 includes the following steps:

[0052] Step 1) The concrete pipe 19 is divided into a rainwater pipe 17 and a sewage pipe 16. A rainwater inspection well 9 and a sewage inspection well 9 are newly built outside the foundation pit 30 by manual excavation. After the foundation pit 30 is excavated to the bottom elevation of the newly built inspection well 9, the upstream and downstream inspection wells 9 are blocked and drainage blocking measures are taken;

[0053] Step 2) When the excavation reaches the elevation of the rainwater pipe 17, the reinforced concrete flat pipe is connected to the inspection well 9, and the rainwater concrete pipe above the foundation pit 30 is sleeved with a steel casing. The interface between the rainwater pipe 17 and the rainwater inspection well 9, and the interface between the steel casing and the rainwater pipe 17 are all encapsulated with concrete, and a rubber ring 8 is provided at the interface between the steel casing and the rainwater pipe 17;

[0054] Step 3) After the Bailey beam 10 is constructed, the rainwater pipe 17 is suspended for protection. A rainwater pipe suspension main beam 15 is arranged along the pipeline direction. A group of suspension points is arranged every 1m on the rainwater pipe suspension main beam 15. The rainwater pipe 17 is placed on the supporting part of the suspension fixture 6 under the multiple groups of suspension points. The basket bolts 18 are adjusted and the steel wire rope is tightened so that the pipeline is in a suspended state and at the same elevation, thereby completing the suspension protection of the rainwater pipe 17.

[0055] Step 4) Continue to dig downward to the elevation of the sewage pipe 16, and set the steel casing for the sewage pipe 16 in the same way as step 2), and the sewage pipe 16 is placed obliquely between the foundation pit 30, and then the sewage pipe 16 is suspended for protection. A plurality of sewage pipe suspension main beams 14 are arranged along the axial direction 31 of the foundation pit 30, and each sewage pipe suspension main beam 14 is provided with a group suspension point. The supporting part of the suspension fixture 6 under the plurality of group suspension points of the plurality of sewage pipe suspension main beams 14 on the sewage pipe 16 is suspended, and the wire rope 5 is tightened to make the pipeline in a suspended state and at the same elevation, thereby completing the suspension protection of the sewage pipe 16;

[0056] Step 5) After the rainwater pipe 17 suspension protection and sewage pipe 16 suspension protection construction are completed, the temporary steel bridge 100 is constructed, and the distribution beam 13 and the bridge deck 12 are laid on the Bailey beam 10 in sequence. When the foundation pit 30 construction is completed and the earthwork is backfilled to the bottom of the rainwater pipe 17 and sewage pipe 16 line, the rainwater pipe 17 and sewage pipe 16 are blocked upstream and downstream, and the temporary steel casing is removed. According to the design concrete pipe requirements, the protection construction of the rainwater pipe 17 and sewage pipe 16 is completed. The bridge deck 12 in the figure is the coverage of the construction of the temporary steel bridge 100.

[0057] The sewage pipe suspension main beam 14 and the rainwater pipe suspension main beam 15 are both I-beam structures. The rainwater steel casing adopts DN1250 steel pipe, and the sewage steel casing adopts DN930 steel pipe with a wall thickness of 6mm. The concrete pipe is sheathed and the joints are sealed with concrete.

[0058] It can be seen that the construction protection process enables in-situ suspension protection without relocating pipelines, which can effectively avoid the risk of pipeline damage due to soil settlement. At the same time, it has the advantage of being able to fully utilize the working space, greatly improving the construction efficiency of subway stations, while saving construction time and construction costs.

[0059] The above is an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. The long-distance suspension protection structure of the concrete pipe in the foundation pit is characterized by: It includes a suspension main beam arranged along the pipeline direction and a plurality of suspension main beams equidistantly arranged along the axial direction of the foundation pit, the suspension main beams arranged along the pipeline direction are equidistantly distributed with group suspension points, each suspension main beam arranged along the axial direction of the foundation pit is provided with a group suspension point, and also includes retaining piles arranged on both sides of the foundation pit, the top surface of the retaining piles is provided with a crown beam, the suspension main beam spans the foundation pit and is placed on the top surface of the crown beam, the two sides of the bottom of the suspension main beam are anchored into the crown beam through suspension supports, the concrete pipe section between the two retaining piles is covered with a steel casing, the two ends of the steel casing are provided with rubber rings at the interface with the concrete pipe, the outside of the interface is encapsulated by concrete, a steel wire rope is suspended on the group suspension point of the suspension main beam, the two ends of the steel wire rope are connected to the suspension fixture suspended under the steel casing through basket bolts, and the suspension fixture is provided with a supporting part in contact with the lower outer edge of the steel casing; The suspended main beam is a Bailey beam, and distribution beams are arranged on the Bailey beam at equal longitudinal intervals. A bridge deck is provided on the distribution beams arranged at equal longitudinal intervals, and the bridge deck has the same elevation as the ground. The distribution beam is an I-beam and the upper chord of the Bailey beam is limited by a clamping plate; the Bailey plate on the Bailey beam is connected to the crown beam through a suspension support, and the suspension support includes an embedded steel plate, a bolt rod embedded assembly and a U-shaped cover plate, and the embedded steel plate is anchored at a corresponding position on the crown beam, and the bottom end of the Bailey plate is inserted into the U-shaped cover plate and contacts the embedded steel plate, and the two ends of the U-shaped cover plate are fastened to the embedded steel plate by the bolt rod embedded assembly; a retaining wall is also provided on the top surface of the crown beam, and the two ends of the Bailey beam are against the retaining wall, and a concrete section is added between the retaining wall and the crown beam.

2. The long-distance suspension protection structure for concrete pipes in foundation pits according to claim 1 is characterized in that: A flexible belt is wound around the outer circumference of the steel casing in contact with the steel wire rope.

3. The long-distance suspension protection structure for concrete pipes in foundation pits according to claim 2 is characterized in that: The vertical position where the flexible belt contacts the steel wire rope is symmetrically provided with Ω-shaped limiters.

4. The long-distance suspension protection structure for concrete pipes in foundation pits according to claim 1 is characterized in that: The suspension fixture is a C-shaped structure with an opening to the side. An inclined surface is provided on the inner side of the bottom of the C-shaped structure. The inclined surface and the inner wall of the C-shaped structure form a supporting portion. The concrete pipe slides into the supporting portion along the inclined surface. During suspension, both ends of the wire rope are connected to the top surface of the suspension fixture with the C-shaped structure through basket bolts.

5. The long-distance suspension protection structure for concrete pipes in foundation pits according to claim 1 or 4, characterized in that: When suspended, the spacing between the steel wire ropes is 1000mm, and reflective tapes are wrapped around both ends of the steel wire ropes.

6. The long-distance suspension protection structure for concrete pipes in foundation pits according to claim 1 is characterized in that: The bolt rod embedded assembly is a group of symmetrically arranged L-shaped structures, with the extended part of the L-shaped structure facing outward and the bottom end thereof anchored in the crown beam.

7. A construction method for a long-distance suspension protection structure for a concrete pipe in a foundation pit, characterized in that The long-distance suspension protection structure for concrete pipes in foundation pits according to any one of claims 1 to 6 further comprises the following steps: Step 1) The concrete pipes are divided into rainwater pipes and sewage pipes. New rainwater inspection wells and sewage inspection wells are built outside the foundation pit by manual excavation. After the foundation pit is excavated to the bottom elevation of the new inspection well, the upstream and downstream inspection wells are blocked and drainage blocking measures are taken; Step 2) When excavating to the elevation of the rainwater pipe, connect the reinforced concrete flat pipe to the inspection well, and connect the steel casing to the rainwater concrete pipe above the foundation pit. The interface between the rainwater pipe and the rainwater inspection well, and the interface between the steel casing and the rainwater pipe are all sealed with concrete, and a rubber ring is provided at the interface between the steel casing and the rainwater pipe; Step 3) After the Bailey beam construction is completed, the rainwater pipe is suspended for protection. A rainwater pipe suspension main beam is laid out along the pipeline direction. A group of suspension points is set every 1m on the rainwater pipe suspension main beam. The rainwater pipe is placed on the supporting part of the suspension fixture under the multiple groups of suspension points. The basket bolts are adjusted and the wire rope is tightened so that the pipeline is in a suspended state and at the same elevation, thereby completing the rainwater pipe suspension protection; Step 4) Continue to dig downward to the elevation of the sewage pipe, and set the steel casing for the sewage pipe in the same way as step 2), and place the sewage pipe obliquely between the foundation pits, and then perform suspension protection construction on the sewage pipe, and arrange several sewage pipe suspension main beams along the axial direction of the foundation pit, and each sewage pipe suspension main beam is provided with a group suspension point, and the supporting part of the suspension fixture under the multiple group suspension points of the several sewage pipe suspension main beams on the sewage pipe is adjusted by tightening the wire rope so that the pipeline is in a suspended state and at the same elevation, and the sewage pipe suspension protection is completed; Step 5) After the construction of rainwater pipe suspension protection and sewage pipe suspension protection is completed, the construction of steel temporary bridge is carried out, and the distribution beam and bridge deck are laid on the Bailey beam in sequence. When the foundation pit construction is completed and the earth is backfilled to the bottom of the rainwater pipe and sewage pipeline, the upstream and downstream of the rainwater pipe and sewage pipe are blocked, the temporary steel casing is removed, and the protection construction of the rainwater pipe and sewage pipe is completed according to the design concrete pipe requirements.

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