Cable protection pipe channel and construction method thereof

Abstract

The invention relates to a cable protection pipe channel and a construction method thereof. The cable protection pipe channel is used for providing an arrangement space for the cable protection pipe combination body in the length direction of a cable and comprises two gravity type cement-soil walls, a foundation trench, a cushion layer, a backfill layer formed by a premixed flow state solidified soil fertilizer groove and a ground surface recovery layer. The two gravity type cement-soil walls are oppositely arranged and extend in the length direction of the cable, the foundation trench is formed between the two gravity type cement-soil walls and extends in the length direction of the cable, the cushion layer is laid at the bottom of the foundation trench, the cable protection pipe combination body is arranged on the cushion layer, and the backfill layer is filled in the foundation trench and completely covers the cushion layer and the cable protection pipe combination body. And the ground surface recovery layer is filled in the foundation trench and completely covers the backfill layer. The construction space can be reduced, waste of materials and resources is reduced, the construction difficulty is lowered, and potential quality hazards and potential safety hazards are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of municipal engineering and electric power engineering construction, and in particular to a cable protection pipe channel and a construction method thereof. Background Art

[0002] The cable protection tube (protection tube) laying technology is widely used in cable line projects. Since the protection tube is mostly laid in the urban road environment and requires a certain burial depth, the protection tube needs to withstand large loads such as soil pressure and vehicle load. In addition, it may encounter external damage caused by drilling and pile foundation construction due to unclear positioning. Therefore, it is necessary to backfill dense sand or encapsulate plain concrete outside the protection tube for protection. At present, typical protection structures such as the attached Figure 1 As shown, it includes a foundation pit with slope excavation, a plain concrete cushion layer arranged at the bottom of the foundation pit and used for placing the cable protection pipe assembly, a sand backfill layer filled in the foundation pit or a compacted backfill soil layer and other structures.

[0003] When laying the above-mentioned cable channel protection structure, it is necessary to set up a supporting structure (such as steel sheet piles, gravity cement soil walls, etc.) and reserve space for pedestrian operations. Therefore, the required construction space is large, which is very difficult in an urban environment where land resources are scarce. At the same time, the soil replaced by the backfill layer or the cable protection pipe assembly during the construction process needs to be discarded, which is not conducive to environmental protection and soil and water conservation, and also causes waste of building materials. The construction process also has problems such as high difficulty, long cycle, and easy ground subsidence, which poses great quality and safety risks. The vibration generated during the construction of steel sheet piles will have a certain impact on the safety of surrounding pipelines or low-lying buildings (structures), and the gravity cement soil wall as a temporary support structure will no longer function after the foundation pit fertilizer trough, resulting in a certain waste of resources. Summary of the invention

[0004] The object of the present invention is to provide a cable protection pipe channel and a construction method thereof which can reduce construction space, reduce material and resource waste, reduce construction difficulty, and reduce quality and safety hazards.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: A cable protection pipe channel is used to provide a layout space for a cable protection pipe assembly along the length direction of the cable, the cable protection pipe channel includes two gravity cement soil walls, a foundation trench, a cushion layer, a backfill layer and a surface recovery layer formed by a premixed fluidized solidified soil fertilizer trough; the two gravity cement soil walls are arranged opposite to each other and extend along the length direction of the cable, the foundation trench is formed between the two gravity cement soil walls and extends along the length direction of the cable, the cushion layer is laid at the bottom of the foundation trench, the cable protection pipe assembly is arranged on the cushion layer, the backfill layer is filled in the foundation trench and completely covers the cushion layer and the cable protection pipe assembly, and the surface recovery layer is filled in the foundation trench and completely covers the backfill layer.

[0006] The top surface of the gravity cement soil wall is flush with the upper surface of the ground recovery layer.

[0007] The gravity cement soil wall adopts a grid type.

[0008] The width of the cushion layer is greater than the width of the cable protection tube assembly.

[0009] The width of the base groove is greater than the width of the cushion layer.

[0010] The cable protection tube assembly comprises a plurality of protection tubes, cables arranged in the protection tubes, and tube pillows for fixing the protection tubes.

[0011] The cable protection tube assembly also includes a reinforced concrete encapsulation layer that wraps the protection tube and the tube pillow.

[0012] The unconfined compressive strength of the premixed fluidized solidified soil is consistent with the compressive strength of the gravity cement soil wall.

[0013] A construction method for a cable protection pipe channel is used to construct the aforementioned cable protection pipe channel, which comprises the following steps: Step 1: Conduct a mix test of premixed fluidized solidified soil and optimize it; Step 2: completing the construction and maintenance of the gravity cement soil wall; Step 3: excavating the foundation trench, transporting the excavated earth to a processing plant for premixed fluidized solidified soil to be used as a raw material for the premixed fluidized solidified soil, and completing the preparation of the premixed fluidized solidified soil based on the test and optimization results; Step 4: performing foundation treatment on the foundation trench, and completing the construction of the cushion layer and the cable protection pipe assembly in sequence; Step 5: using the prepared premixed fluidized solidified soil fertilizer tank to form the backfill layer and complete the maintenance of the backfill layer; Step 6: Complete the construction of the surface restoration layer.

[0014] In step 3, the bottom width of the foundation trench is selected according to the construction method.

[0015] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: the present invention can reduce construction space, reduce material and resource waste, reduce construction difficulty, and reduce quality and safety risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Attached Figure 1 It is a cross-sectional schematic diagram of an existing cable protection tube protection structure.

[0017] Attached Figure 2 It is a cross-sectional schematic diagram of the cable protection tube channel of the present invention.

[0018] Attached Figure 3 It is a cross-sectional schematic diagram of the cable protection tube channel of the present invention.

[0019] Attached Figure 4 The present invention is a flow chart of the construction method of the cable protection pipe channel.

[0020] Attached Figure 5 It is a schematic diagram of steps 1 to 4 in the construction method of the cable protection pipe channel of the present invention.

[0021] Attached Figure 6 It is a schematic diagram of steps 5 to 6 in the construction method of the cable protection pipe channel of the present invention.

[0022] Attached Figure 7 It is a schematic diagram of the cable protection tube channel and reserved space of the present invention.

[0023] In the above figures: 1. Gravity cement soil wall; 2. Foundation trench; 3. Cushion layer; 4. Backfill layer; 5. Surface restoration layer; 6. Cable protection pipe assembly. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the embodiments shown in the accompanying drawings.

[0025] Embodiment 1: The cable protection tube channel is used to provide a layout space for the cable protection tube assembly 6 along the length direction of the cable. Figure 2 As shown, a cable protection pipe channel includes two gravity cement soil walls 1, a foundation trench 2, a cushion layer 3, a backfill layer 4 and a surface recovery layer 5.

[0026] Two gravity cement soil walls 1 are arranged opposite to each other and extend along the length direction of the cable (i.e., the direction perpendicular to the drawing). The gravity cement soil walls 1 are grid-type. The foundation trench 2 is formed between the two gravity cement soil walls 1 and extends along the length direction of the cable. The two gravity cement soil walls 1 form the side walls of the foundation trench 2. The cross section of the foundation trench 2 is rectangular. The cushion layer 3 is laid at the bottom of the foundation trench 2. The width of the foundation trench 2 is greater than the width of the cushion layer 3. The cable protection pipe assembly 6 is arranged on the cushion layer 3. The width of the cushion layer 3 is greater than the width of the cable protection pipe assembly 6. The backfill layer 4 is formed by a premixed fluidized solidified soil fertilizer trough, which is filled in the foundation trench 2 and completely covers the cushion layer 3 and the cable protection pipe assembly 6. The unconfined compressive strength of the premixed fluidized solidified soil is consistent with the compressive strength of the gravity cement soil wall 1. The surface recovery layer 5 is filled in the foundation trench 2 and completely covers the backfill layer 4. The top surface of the gravity cement soil wall 1 is flush with the upper surface of the ground recovery layer 5 and is also flush with the ground at the construction site.

[0027] The cable protection tube assembly 6 includes a plurality of protection tubes arranged in an array, cables disposed in the protection tubes, and tube pillows for fixing the protection tubes, and may also include a reinforced concrete encapsulation layer that wraps the protection tubes and the tube pillows. The width and height of the reinforced concrete encapsulation layer are based on the outer contour size of the outermost protection tube to form a geometric outer contour, for example, the cross section of the cable protection tube assembly 6 is rectangular.

[0028] In the above scheme, through the combined action of the premixed fluidized solidified soil and the gravity cement soil wall 1, a door-shaped cement soil wall with an unconfined compressive strength of not less than 0.8 MPa is formed outside the cable protection pipe assembly 6. Figure 3 shown.

[0029] As attached Figure 4 As shown, a construction method for a cable protection pipe channel is used to construct the aforementioned cable protection pipe channel, which comprises the following steps: Step 1: Conduct a mix test of premixed fluidized solidified soil and optimize it; Step 2: completing the construction and maintenance of the gravity cement soil wall 1; Step 3: excavate the foundation trench 2, generally the excavation depth does not exceed 5.0m, transport the excavated soil to the processing plant of premixed fluidized solidified soil as the raw material of premixed fluidized solidified soil, and complete the preparation of premixed fluidized solidified soil based on the test and optimization results; Step 4: Construction of the power channel structure, including ground treatment of the foundation trench 2, construction of the cushion layer 3 and the cable protection pipe assembly 6, and necessary reinforcement and concrete maintenance. The cable protection pipe channel after step 4 is as shown in the attached figure. Figure 5 As shown; Step 5: Use the prepared premixed fluidized solidified soil fertilizer tank to form a backfill layer 4 and complete the curing of the backfill layer 4, the curing period is 7 days; Step 6: Complete the construction of the surface restoration layer 5. The cable protection pipe channel after step 6 is as shown in the attached figure. Figure 6 shown.

[0030] Among them, in step 3, the bottom width of the foundation trench 2 is selected according to the construction method.

[0031] During the actual construction of the project, the dimensions of the base trench 2 of the protective pipe channel include the following parts: (1) The outer package range of the cable protection tube is composed of the spacing of the cable protection tube, which includes the rows and columns formed by the arrangement and spacing of the cable protection tube. According to the different diameters of the tubes, the horizontal spacing is generally 230mm~280mm, and the vertical spacing is 240mm~280mm. The net distance between the protection tubes is mostly controlled by the tube pillow, and the allowable deviation of the spacing value is: the spacing between the holes in the same row is ≤5mm, and the vertical spacing is ≤20mm; (2) The extension length of the outer assembly 6 of the protection tube is usually not less than half of the center distance of the protection tube row; (3) When the foundation trench 2 of the protection pipe is constructed by slope reduction, the width of its bottom shall not be less than 600 mm; when the retaining structure is used for construction, its width shall not be less than 800 mm; (4) The soil cover thickness on the top of the protective pipe shall not be less than 0.50m. In order to meet the requirements of the longitudinal slope, the soil cover thickness is usually set to 0.70m; (5) The width of the protective pipe construction work surface. In addition to the width of the protective pipe, it is also necessary to consider the operating space under the side wall of the protective pipe, the supporting structure of the foundation trench 2, the construction work enclosure on the top of the protective pipe, etc.; (6) It is strictly prohibited to pile up soil, equipment or materials within 1.0m of the edge of foundation pit 2, and the pile height shall be ≤1.5m; Considering the needs of construction work, space for temporary earthwork stacking, excavator travel and turning, and pipe stacking needs to be reserved on one side of the foundation trench 2, as shown in the attached Figure 7 In general, the reserved width on one side of the channel should not be less than 4.0m; if the side is not considered for loading and construction operations, the space should not be less than 1.0m. At this time, the width of the drainage pipe construction surface should be at least 8.0m. If the main urban road is occupied, it needs to block 3 lanes (each lane is 3.5m to 3.75m wide).

[0032] In order to reduce the width of the cable protection channel supported by gravity retaining wall, the above scheme uses premixed fluidized solidified soil to replace the existing sand encapsulation layer or reinforced concrete encapsulation structure layer. In terms of the operating space for people, the outer protection width of the drainage pipe can be cancelled. Under normal circumstances, the reinforced concrete encapsulation can reduce the width by about 300mm, and at the same time reduce the distance from the top of the drainage pipe to the top of the protective layer by more than 200mm. At the same time, considering the low difficulty of laying drainage pipes, simple procedures, and shallow trenches, the operating space for people on both sides of the drainage pipe can be reduced to 400mm, further reducing the width of the foundation trench 2 by 0.80m. After comprehensive analysis, the use of premixed fluidized solidified soil fertilizer trough to replace the existing sand backfill or reinforced concrete encapsulation backfill can reduce the drainage pipe and its support area by about 1.10m, and the construction road occupation can also be reduced to within the range of 2 lanes, with significant benefits.

[0033] Due to the use of premixed fluidized solidified soil fertilizer trough, the thickness of the soil cover on the top of the protection pipe can be calculated from the outer contour of the protection pipe. Compared with the existing design, the excavation depth of the foundation pit can be reduced by more than 200mm. The reduced excavation depth of the foundation pit is used to calculate the width and insertion depth of the gravity retaining wall. The gravity cement soil wall 1 adopts a grid type. Depending on the soil quality, the replacement rate is 0.6-0.8. Considering the working conditions of backfilling with premixed fluidized soil, the excavation width of the foundation pit is calculated based on the 400mm man-operating space reserved on both sides of the outer side of the protection pipe. Compared with the existing design, the excavation width of the foundation trench 2 is reduced by about 1.0m. Construction of gravity cement soil wall 1, after curing to meet the excavation strength requirements (28d unconfined compressive strength is not less than 0.8MPa), excavate the foundation trench 2 to the bottom of the pit, and apply the cushion layer 3 after necessary foundation treatment; use pipe pillows to fix the protection pipe and weld it longitudinally. Pour the premixed fluidized solidified soil in the foundation trench 2 according to the proportion. When the slump is less than 150mm, it is advisable to vibrate on site and fill it in layers to 500mm above the top of the drainage pipe. After the premixed fluidized solidified soil is cured for 7 days, the top is applied to the ground to restore the ground function.

[0034] Compared with the technical solution of backfilling with compacted sand around the pipe, the technical solution of using a premixed fluidized solidified soil and fertilizer tank has the following advantages: (1) Directly using premixed fluidized solidified soil as the top protective layer can reduce the height of the pipe top protective layer by more than 200 mm, reduce the excavation depth of the foundation trench 2, and reasonably reduce the engineering workload of the gravity cement soil wall 1; (2) The excess soil in the foundation trench 2 can be used as the raw material of the premixed fluidized solidified soil to the maximum extent, thus reducing the amount of abandoned soil and the amount of fine sand, a good building material, which is green and environmentally friendly; (3) The unconfined compressive strength of the premixed fluidized soil can reach 0.4 MPa to 1.0 MPa. In this scheme, the strength requirement of the premixed fluidized soil at the top of the pipe can be 0.8 MPa, which is consistent with the gravity cement soil wall 1. After the fluidized soil fertilizer trough is used, it will form a joint protective wall with the gravity retaining wall. (4) After the curing period reaches 28 days, a "door"-shaped heavy cement soil wall will be formed on the upper side and left and right sides of the existing protection pipe to protect the safety of the cable and protection pipe. The "door" cement soil reinforcement wall after the age of more than 28 days can meet the requirements of protecting the power pipe from external impact loads and external breaking loads.

[0035] In order to meet the requirements of surface driving or planting, the gravity cement soil wall 1 within a certain height (eg 0.30 m) below the surface can be chiseled out and rebuilt into a road surface structure layer or cultivated soil to meet the use requirements of the topsoil.

[0036] From the schematic diagram of the cable protection tube channel above, it can be seen that: (1) The premixed fluidized solidified soil and fertilizer tank has almost no significant impact on the construction process of the gravity retaining wall; (2) The use of premixed fluidized solidified soil can basically utilize the earth excavated from the foundation trench 2, the earth backfilled on the surface, and the drainage pipes and their encapsulating structure layers to replace part of the soil, which can be used as external waste soil; (3) The premixed fluidized solidified soil has almost no significant impact on the design calculation of the cable foundation trench 2, and the impact of this part can be ignored when calculating the temporary support structure.

[0037] Compared with the existing drainage channels protected by backfill sand or encapsulated by reinforced concrete, this solution has the following advantages: 1. The excavated slag is directly used as the raw material of premixed fluidized solidified soil, which reduces the volume of abandoned soil from the source and realizes green environmental protection by reducing the cable pipe laying project; 2. It avoids the problems of urban environmental construction such as large area occupied by slope excavation and large enclosure of construction machinery and equipment such as steel sheet piles. At the same time, it also makes full use of the gravity cement soil wall 1, realizes the permanent and temporary combination of the gravity cement soil wall 1, and has a series of advantages such as low carbon and environmental protection, especially suitable for projects with complex ground and underground environments that require protective measures for power protection pipes; 3. Through the combined action of the gravity cement soil wall 1 and the premixed fluidized solidified soil, a door-shaped protective wall is formed outside the power pipe. The unconfined compressive strength of the wall reaches 0.80 MPa, and the cable channel is safe and controllable to a certain extent under the influence of external forces; 4. The use of premixed fluidized solidified soil and fertilizer trough avoids manual tamping of sand or manual work such as formwork support, steel bar tying, and concrete pouring, thus improving the safety of cable pipe laying projects, especially in soft soil layers; 5. The premixed fluidized solidified soil has been upgraded from the existing role of fertilizer trough to a "hard shell layer" that protects underground pipelines or structures after construction as part of the permanent structure, thus achieving efficient use of resources.

[0038] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A cable protection tube channel, used to provide a layout space for a cable protection tube assembly along the length direction of the cable, characterized in that: The cable protection pipe channel includes two gravity cement soil walls, a foundation trench, a cushion layer, a backfill layer and a surface recovery layer formed by a premixed fluidized solidified soil fertilizer trough; the two gravity cement soil walls are arranged opposite to each other and extend along the length direction of the cable, the foundation trench is formed between the two gravity cement soil walls and extends along the length direction of the cable, the cushion layer is laid at the bottom of the foundation trench, the cable protection pipe assembly is arranged on the cushion layer, the backfill layer is filled in the foundation trench and completely covers the cushion layer and the cable protection pipe assembly, and the surface recovery layer is filled in the foundation trench and completely covers the backfill layer.

2. The cable protection tube channel according to claim 1, characterized in that: The top surface of the gravity cement soil wall is flush with the upper surface of the ground recovery layer.

3. The cable protection tube channel according to claim 1, characterized in that: The gravity cement soil wall adopts a grid type.

4. The cable protection tube channel according to claim 1, characterized in that: The width of the cushion layer is greater than the width of the cable protection tube assembly.

5. The cable protection tube channel according to claim 4, characterized in that: The width of the base groove is greater than the width of the cushion layer.

6. The cable protection tube channel according to claim 1, characterized in that: The cable protection tube assembly comprises a plurality of protection tubes, cables arranged in the protection tubes, and tube pillows for fixing the protection tubes.

7. The cable protection tube channel according to claim 6, characterized in that: The cable protection tube assembly also includes a reinforced concrete encapsulation layer that wraps the protection tube and the tube pillow.

8. The cable protection tube channel according to claim 1, characterized in that: The unconfined compressive strength of the premixed fluidized solidified soil is consistent with the compressive strength of the gravity cement soil wall.

9. A construction method for a cable protection pipe channel, used to construct the cable protection pipe channel as claimed in any one of claims 1 to 8, characterized in that: The construction method of the cable protection pipe channel comprises the following steps: Step 1: Conduct a mix test of premixed fluidized solidified soil and optimize it; Step 2: completing the construction and maintenance of the gravity cement soil wall; Step 3: excavating the foundation trench, transporting the excavated earth to a processing plant for premixed fluidized solidified soil to be used as a raw material for the premixed fluidized solidified soil, and completing the preparation of the premixed fluidized solidified soil based on the test and optimization results; Step 4: Performing foundation treatment on the foundation trench, and completing the construction of the cushion layer and the cable protection tube assembly in sequence; Step 5: using the prepared premixed fluidized solidified soil fertilizer tank to form the backfill layer and complete the maintenance of the backfill layer; Step 6: Complete the construction of the surface restoration layer.

10. The construction method of the cable protection pipe channel according to claim 9, characterized in that: In step 3, the bottom width of the foundation trench is selected according to the construction method.

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