A method for laying pipelines for municipal pipe networks

Abstract

This invention relates to a method for laying pipes for municipal pipe networks, comprising the following steps: S100: excavating a pipe trench; S200: laying a permeable base layer; S300: installing sleepers; S400: backfilling the slope filler; S500: setting up slope support; S600: installing pipe supports and placing the pipe; S700: installing the upper beam frame and setting pipe clamps; S800: backfilling the pipe trench. This invention uses permeable materials to lay the bottom and sides of the pipe trench, thereby constructing a water collection corridor. This allows groundwater seepage and lateral infiltration to be actively guided to the perforated drainage pipe at the toe of the slope and quickly discharged into the drainage well. On the one hand, it prevents the softening and liquefaction of the base soil due to long-term soaking and scouring, and prevents uneven settlement caused by a decrease in the bearing capacity of the foundation. On the other hand, it avoids local water accumulation in the pipe trench, prevents the pipe from floating due to water immersion, avoids the alternating effects of settlement and floating or uneven spatial distribution, and avoids local shear forces caused by local differential displacement at the pipe joints, ensuring the stability of the pipe axis.

Description

Technical Field

[0001] This invention relates to the field of pipeline laying technology, specifically to a method for laying pipelines for municipal pipe networks. Background Technology

[0002] With the continuous advancement of urbanization, municipal pipeline networks, as a crucial infrastructure for ensuring urban operation, are expanding in both coverage and scale. Currently, the laying of municipal pipeline networks mainly employs conventional construction methods such as excavating trenches, installing pipelines, and backfilling with earthwork.

[0003] However, when laying pipelines in special geographical areas with high groundwater levels or in water-rich zones, the groundwater pressure is high, which can easily cause significant groundwater upwelling. After the trench is backfilled, groundwater will enter from the bottom and side walls of the trench, causing local water accumulation in the trench and making the main pipeline soaked by external water.

[0004] On the one hand, the foundation soil beneath the pipeline is prone to softening, liquefaction, or loss of fine particles due to long-term soaking and scouring by groundwater, which leads to a decrease in the bearing capacity of the foundation, resulting in uneven settlement of the pipeline and the possible formation of cavities beneath the pipeline.

[0005] On the other hand, external water accumulation exerts a huge upward buoyancy on the hollow pipe structure. Especially after long-term settling and the formation of cavities, the local water accumulation intensifies, making the pipe tend to float upward.

[0006] This alternating effect of settling and floating, or uneven spatial distribution, causes local displacement and axial deviation in the pipeline in the longitudinal direction. Especially in weak parts such as pipe joints and manhole connections, huge concentrated shear forces are generated, which can easily lead to pipeline deformation, cracks, damage or even rupture, significantly shortening the service life of the pipeline.

[0007] Therefore, it is necessary to study a method for laying pipelines for municipal pipe networks. Summary of the Invention

[0008] Therefore, the purpose of this invention is to provide a method for laying pipelines for municipal pipe networks, which can effectively solve the problem that existing pipeline laying fixed structures are easily affected by groundwater and thus settle or float.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for laying pipelines for municipal pipe networks includes the following steps: S100: Excavation of pipe trenches; Excavate the pipe trench so that the left and right sides of the trench form a downward sloping surface; S200: Laying a permeable base layer; A permeable base layer is continuously laid at the bottom of the trench, and drainage pipes are continuously buried on the left and right sides of the permeable base layer. The upper part of the drainage pipes is provided with water inlet mesh, and the drainage pipes are connected to the drainage well. S300: Install sleepers; Fixed sleepers are laid at intervals along the length of the trench on the permeable base layer; S400: Backfill material for slope surfaces; Slope filler is continuously laid on both sides of the permeable base layer and on both sides of the trench. The slope filler is made of permeable material to form a permeable channel on the slope. S500: Slope protection measures are installed; Fixed support plates are laid on the surface of the slope fill material, with the support plates spaced apart along the length of the trench. S600: Install pipe supports and place pipes; Install pipe supports on the sleepers and place the pipes on the pipe supports; S700: Install the upper beam frame and set the pipe clamps; A top beam is fixedly connected between the two corresponding guard plates on the left and right sides, and the top beam is located above the pipe; Pipe clamps are installed at intervals along the pipeline extension direction. The upper end of the pipe clamp is fixedly connected to the upper beam frame, and the lower end of the pipe clamp is fixedly connected to the sleeper through the lower beam frame. S800: Backfill trench; First, permeable material is used to backfill the lower part of the pipe, forming a water collection corridor that connects to the drainage pipe with the permeable base layer and the permeable channel of the slope; then the pipe trench is backfilled normally to complete the construction.

[0010] Furthermore, in step S100, the area below the middle of both slopes is widened to the side to form an widened excavation zone; In step S400, the slope filler is backfilled in the excavated area.

[0011] Furthermore, after the slope filler is used, the slope is restored to its original slope gradient; The support plate is attached parallel to the slope surface, with the top of the slope support attached to the top of the slope and the bottom of the slope support attached to the slope fill.

[0012] Furthermore, the slope filler includes bottom filler and middle filler, with the bottom filler having greater permeability than the middle filler.

[0013] Furthermore, the support plate is anchored to the trench sidewall via anti-buoyancy anchor bolts; the sleepers are anchored to the base via anti-buoyancy anchor bolts.

[0014] Furthermore, in step S500, a lower beam frame is fixedly connected to the sleeper, and the lower beam frame is horizontally and symmetrically distributed on both sides of the pipeline; and the support plate is fixedly connected to the lower beam frame through connectors. In step S700, the lower end of the pipe clamp is fixedly connected to the lower beam frame.

[0015] Furthermore, the support plates are arranged correspondingly to the sleepers, and the bottom of the support plates is fixedly connected to the lower beam frame.

[0016] Furthermore, upper flange plates and lower flange plates extending in the front-rear direction are respectively fixedly connected to the upper beam frame and the lower beam frame; In step S800, when backfilling to the positions of the upper and lower flange plates, the upper and lower flange plates are installed accordingly.

[0017] Furthermore, at least two sets of pipe supports are arranged in parallel on the left and right sides, and the pipe supports extend continuously along the length of the pipe trench.

[0018] Furthermore, the inner wall of the trench and the upper surface of the permeable base layer are both covered with a geotextile layer.

[0019] The beneficial effects of the above technical solution are: (1) The present invention uses permeable material to lay the bottom and sides of the pipe trench to construct a water collection corridor, so that the underground water and lateral seepage are actively guided to the perforated drainage pipe at the slope toe and quickly discharged into the drainage well. It can actively release pressure and reduce the hydrostatic pressure around the pipe. On the one hand, it prevents the softening and liquefaction of the foundation soil due to long-term soaking and scouring, and prevents uneven settlement caused by the decline in the bearing capacity of the foundation. On the other hand, it can avoid local water accumulation in the pipe trench, prevent the pipe from floating due to water immersion, avoid the alternating effect of settlement and floating or uneven spatial distribution, avoid local shear force caused by local differential displacement at the pipe interface, and ensure the stability of the pipe axis.

[0020] (2) The present invention efficiently transmits the vertical upward buoyancy force on the pipeline to the lateral support plate with slope setting through the pipe clamp and the upper beam frame. Since the support plate is attached to the slope fill and is pressed by the self-weight of the subsequent backfill soil, the originally destructive upward buoyancy force is transformed into the squeezing force on the slope fill and the internal tension on the system skeleton. The closed mechanical frame of "pipe clamp-beam frame-support plate-sleeper" greatly improves the anti-buoyancy stiffness of the structure under high water level conditions. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view after the completion of the construction of this invention; Figure 2 for Figure 1 A magnified view of a section at point A in the middle; Figure 3 This is a schematic diagram of the S100 pipe trench after excavation; Figure 4 A schematic diagram showing the S200 after a permeable base layer has been laid. Figure 5 A schematic diagram showing the S300 after sleepers have been installed. Figure 6 This is a schematic diagram of the slope surface after backfilling with filler material in S400. Figure 7 A schematic diagram showing the slope support installation for the S500. Figure 8 A schematic diagram showing the installation of pipe supports and placement of pipes on the S600. Figure 9 A schematic diagram showing the installation of the upper beam frame and the installation of pipe clamps on the S700. Attached reference numerals: 1. Pipe trench; 2. Permeable base layer; 3. Drainage pipe; 4. Sleeper; 5. Slope filler; 6. Support plate; 7. Pipe support; 8. Pipe clamp; 9. Upper beam frame; 10. Anti-buoyancy anchor; 11. Lower beam frame; 12. Connector; 13. Upper flange plate; 14. Lower flange plate; 15. Geotextile layer; 16. Pipe; 101. Slope; 102. Widened excavation area; 301. Inlet mesh; 501. Slope bottom filler; 502. Slope middle filler. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: This embodiment aims to provide a pipeline laying method for municipal pipe networks, which is mainly used for laying drainage pipes in water-rich areas, and addresses the problem that existing pipeline laying fixed structures are easily affected by groundwater, resulting in settlement and floating.

[0023] The method for laying municipal pipelines (type 16) includes the following steps: S100: Excavate trench 1; like Figure 3 Excavate the trench 1 to form downward sloping slopes 101 on both sides of the trench 1; in this embodiment, the area below the middle of the slopes 101 on both sides is further enlarged to form an enlarged excavation area 102, which is used for backfilling the slope filler 5.

[0024] The base layer of trench 1 should be designed as a drainage structure with a higher center and lower left and right sides to facilitate the drainage of water accumulated in trench 1 to the left and right sides. After excavation, the base layer of trench 1 needs to be compacted, and the slope 101 needs to be leveled and compacted.

[0025] S200: Lay a permeable base layer 2; like Figure 4 A permeable base layer 2 is continuously laid at the bottom of the trench 1. The permeable base layer 2 is made of highly permeable material, such as 40-80mm large crushed stone. Its high porosity eliminates dynamic water pressure and prevents it from softening or liquefying and settling.

[0026] During the laying of the permeable base layer, drainage pipes 3 are continuously buried on both sides. The upper part of the drainage pipe 3 is provided with water inlet mesh 301 for draining the water in the pipe trench 1. The water inlet mesh 301 can be obtained by opening through holes in the drainage pipe 3 and wrapping geotextile around it. The purpose is to intercept soil and sand particles and only allow water to pass through.

[0027] The drainage pipe 3 is connected to the drainage well. In this embodiment, the pipe 16 is an underground drainage pipe 3. In the prior art, it is usually set at the corner of the pipe 16, which will not be described in detail here.

[0028] S300: Install sleepers 4; like Figure 5 Fixed sleepers 4 are laid at intervals along the length of the trench 1 on the permeable base layer 2. The sleepers 4 are used to evenly distribute the self-weight and dynamic load of the pipe 16 onto the large area of ​​the permeable base layer 2, providing a fixed foundation for the pipe 16 support 7. The sleepers 4 can be made of wood or precast concrete slabs. The sleepers 4 are anchored to the base of the trench 1 by anti-buoyancy anchors 10. The anti-buoyancy anchors 10 can also be anti-buoyancy anchors 10 with anti-buoyancy rings or enlarged bladder anti-buoyancy anchors 10. The anti-buoyancy anchors 10 can be anchored into the base before laying the permeable base layer, and then the permeable base layer is laid, and the sleepers 4 are passed through their ends and anchored to them.

[0029] S400: Backfill material for slope surfaces, 5; like Figure 6 On both sides of the permeable base layer 2 and the two side walls of the pipe trench 1, slope filler 5 is continuously laid. The slope filler 5 is backfilled in the excavated area 102. The slope of the excavated area 102 is greater than the slope of the pipe trench 1. After the slope filler 5 is filled, the slope 101 is restored to the original slope 101, so as to facilitate the subsequent support plate 6 for support and reinforcement.

[0030] The slope filler 5 uses permeable materials to form permeable channels on the slope 101, providing downward flow channels for lateral infiltration. Specifically, the slope filler 5 includes bottom filler 501 and middle filler 502. The bottom filler 501 has higher permeability than the middle filler 502. The bottom filler 501 uses 20mm-40mm medium-sized graded crushed stone to ensure the flow of laterally infiltrated water, which then flows downward into the permeable base layer 2 and the drainage pipe 3. The middle filler is filled with 5mm-20mm fine crushed stone or well-graded coarse sand to facilitate upward stacking without slippage. The angle of repose of the middle filler 502 must be greater than the slope gradient to prevent the middle filler 502 from slipping off naturally; compaction reinforcement can be carried out if necessary.

[0031] S500: Slope protection measures are installed; like Figure 7Fixed support plates 6 are laid on the surface of the slope fill 5. The support plates 6 are arranged at intervals along the length of the trench 1. Ribs can be fixedly connected between adjacent support plates 6 to form a skeleton structure to protect the slope. The support plates 6 are parallel to the slope surface 101, with the top of the slope support attached to the top of the slope and the bottom of the slope support attached to the slope fill 5. The support plates 6 are anchored to the side wall of the trench 1 by anti-buoyancy anchor rods 10, which can be done after the slope fill 5 is laid, to reinforce the slope fill 5 in conjunction with the support plates 6.

[0032] Furthermore, such as Figure 2 In this embodiment, a lower beam frame 11 is bolted to the sleeper 4, and the lower beam frame 11 is horizontally and symmetrically distributed on both sides of the pipe 16. The support plate 6 is fixedly connected to the lower beam frame 11 by a connector 12, which is an angle steel and a bolt, so that the side support and bottom support form an integrated force-bearing system, providing additional support for the support plate 6. The support plate 6 is arranged correspondingly to the sleeper 4, and the bottom of the support plate 6 is fixedly connected to the lower beam frame 11. Each sleeper 4 has a support plate 6 on both sides.

[0033] S600: Install pipe 16 support 7 and place pipe 16; like Figure 8 Pipe 16 supports 7 are fixedly installed on sleepers 4, and pipe 16 is placed on pipe 16 supports 7. At least two sets of pipe 16 supports 7 are arranged parallel to each other on the left and right sides, and pipe 16 supports 7 extend continuously along the length of pipe trench 1 to provide stable support for pipe 16.

[0034] Pipeline 16 can be laid using a hoisting mechanism. Crushed stone can be laid under pipeline 16 in advance to facilitate subsequent backfilling.

[0035] S700: Install the upper beam frame 9 and set the pipe clamps 8; like Figure 9 An upper beam 9 is fixedly connected between the two corresponding left and right support plates 6. The upper beam 9 is located above the pipe 16. On the one hand, the upper beam 9 provides an upper fixed limit foundation for the pipe clamp 8 to effectively resist floating or settling. On the other hand, it forms the left and right support plates 6 into a whole to bear the force and enhance the support capacity.

[0036] Pipe clamps 8 are installed at intervals along the extension direction of pipe 16. The pipe clamps 8 are arranged at intervals. The upper end of the pipe clamp 8 is fixedly connected to the upper beam 9 to form an upper limit. The lower end of the pipe clamp 8 is fixedly connected to the sleeper 4. Specifically, it is fixedly connected to the lower beam 11 through angle steel to form a bottom limit, thereby limiting and fixing the upper and lower sides of pipe 16.

[0037] S800: Backfill trench 1; First, permeable material is used to backfill the lower part of pipe 16, forming a permeable backfill layer. This layer, together with the permeable base layer and the permeable slope channel, forms a water collection gallery connecting to drainage pipe 3. This allows water entering trench 1 to accumulate and temporarily remain in the water collection gallery formed by the permeable material, gradually draining into drainage pipe 3. This prevents water accumulation and soil erosion, which could lead to floating or settling. The permeable material used in this step can be the same 20mm-40mm medium-sized graded crushed stone as the slope bottom filler 501. Afterward, conventional backfill soil is used to backfill trench 1 to complete the construction.

[0038] Furthermore, upper flange plate 13 and lower flange plate 14 extending in the front-rear direction are fixedly connected to the upper beam frame 9 and lower beam frame 11, respectively. The upper flange plate 13 is buried in the conventional backfill soil, and the lower flange plate 14 is buried in the permeable backfill layer. When backfilling reaches the position of the upper flange plate 13 and lower flange plate 14, the upper flange plate 13 and lower flange plate 14 are installed accordingly. The upper flange plate 13 and lower flange plate 14 can be cantilever plates extending in the front-rear direction, or they can be fixedly connected between the upper beam frame 9 and lower beam frame 11 that are adjacent to each other in the front and rear directions. This is intended to cooperate with the backfill structure to increase the longitudinal displacement resistance and resist the settlement and floating movement of the pipeline 16.

[0039] In this embodiment, in order to prevent soil erosion, geotextile is laid between two different soil bodies or backfill bodies. Specifically, geotextile layer 15 is laid on the inner wall of the trench 1 (including the base layer and side wall of the trench 1). Geotextile layer 15 is laid between the permeable base layer and the slope fill 5 and the permeable backfill layer. Geotextile layer 15 is also set between the slope fill 502 and the slope bottom fill 501. The geotextile layer 15 at different locations is selected separately according to the needs of the two adjacent soil materials, in order to avoid small-diameter fill or soil from entering the pores of large-diameter fill and causing blockage and loss.

Claims

1. A method of pipe laying for a municipal network, characterised in that: Includes the following steps: S100: Excavation of pipe trench (1); Excavate the pipe trench (1) to form a downward sloping surface (101) on both sides of the pipe trench (1); S200: Lay a permeable base layer (2); A permeable base layer (2) is continuously laid at the bottom of the trench (1), and drainage pipes (3) are continuously buried on the left and right sides of the permeable base layer. A water inlet mesh (301) is opened at the top of the drainage pipe (3), and the drainage pipe (3) is connected to the drainage well. S300: Install sleepers (4); Fixed sleepers (4) are laid at intervals along the length of the trench (1) on the permeable base layer (2); S400: Backfill slope fill material (5); On both sides of the permeable base layer (2) and the two side walls of the pipe trench (1), slope filler (5) is continuously laid. The slope filler (5) is made of permeable material to form a slope permeable channel on the slope (101). S500: Slope protection measures are installed; Fixed support plates (6) are laid on the surface of the slope filler (5), and the support plates (6) are arranged at intervals along the length of the trench (1). S600: Install pipe support (7) and place pipe (16); Install pipe supports (7) on sleepers (4) and place pipes (16) on pipe supports (7); S700: Install the upper beam frame (9) and set the pipe clamps (8); The upper beam frame (9) is fixedly connected between the two corresponding guard plates (6) on the left and right sides, and the upper beam frame (9) is located above the pipe (16); Pipe clamps (8) are installed at intervals along the extension direction of the pipe (16). The upper end of the pipe clamp (8) is fixedly connected to the upper beam frame (9), and the lower end of the pipe clamp (8) is fixedly connected to the sleeper (4) through the lower beam frame (11). S800: Backfilled pipe trench (1); First, use permeable material to backfill the lower part of the pipe (16), forming a water collection corridor that connects to the drainage pipe (3) with the permeable base layer (2) and the permeable channel of the slope; then backfill the pipe trench (1) normally to complete the construction.

2. The method for laying municipal pipelines according to claim 1, characterized in that: In step S100, the area below the middle of the two slopes (101) is widened to the side to form the widened excavation area (102); In step S400, the slope filler (5) is backfilled into the excavated area (102).

3. A method of laying a pipe for a municipal network according to claim 2, characterised in that: After the slope filler (5) is filled, the slope (101) is restored to the original slope (101); The support plate (6) is attached parallel to the slope surface (101), the top of the slope surface (101) support is attached to the top of the slope, and the bottom of the slope surface (101) support is attached to the slope filler (5).

4. A method of laying a pipe for a municipal network according to claim 3, characterised in that: The slope filler (5) includes bottom filler (501) and middle filler (502), with the bottom filler (501) having greater permeability than the middle filler (502).

5. A method of laying a pipe for a municipal network according to any one of claims 1-4, characterized in that: The support plate (6) is anchored to the side wall of the trench (1) by anti-buoyancy anchor rods (10); the sleeper (4) is anchored to the base by anti-buoyancy anchor rods (10).

6. A method for laying pipelines for municipal pipe networks according to any one of claims 1-4, characterized in that: In step S500, a lower beam frame (11) is fixedly connected to the sleeper (4), and the lower beam frame (11) is horizontally and symmetrically distributed on both sides of the pipe (16); and the support plate (6) is fixedly connected to the lower beam frame (11) through the connector (12); In step S700, the lower end of the pipe clamp (8) is fixedly connected to the lower beam frame (11).

7. A method of laying a pipe for a municipal network according to claim 6, characterised in that: The support plate (6) is arranged in correspondence with the sleeper (4), and the bottom of the support plate (6) is fixedly connected to the lower beam frame (11).

8. A method for laying municipal pipelines according to claim 7, characterized in that: The upper beam frame (9) and the lower beam frame (11) are respectively fixedly connected with an upper flange plate (13) and a lower flange plate (14) extending in the front-rear direction; In step S800, when backfilling to the positions of the upper flange plate (13) and the lower flange plate (14), the upper flange plate (13) and the lower flange plate (14) are installed accordingly.

9. A method of laying a pipe for a municipal network according to any one of claims 1-4, characterized in that: At least two sets of pipe supports (7) are arranged in parallel on the left and right sides, and the pipe supports (7) extend continuously along the length of the pipe trench (1).

10. A method of laying a pipe for a municipal network according to any one of claims 1-4, characterized in that: The inner wall of the trench (1) and the upper surface of the permeable base layer (2) are both covered with geotextile layer (15).

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