A method for the rapid installation of a non-excavation underground pipeline cover protection structure

Abstract

The present application belongs to the technical field of underground structure, and particularly relates to a kind of fast, non-excavation underground pipeline cover plate protection structure construction method.The underground pipeline cover plate protection structure designed by the present application comprises a plurality of steel pipe sleeves, prefabricated cover plates and impermeable double-layer geotextiles filled with high-compressibility granular materials;the steel pipe sleeves are vertically arranged on both sides of the pipeline as the support foundation of the prefabricated pipeline cover plates;the undersides of the prefabricated pipeline cover plates are provided with gables embedded in the upper openings of the steel pipe sleeves to fix the positions;the double-layer geotextiles are laid between the steel pipe sleeves on both sides of the pipeline to fix and prevent running and leakage.The construction includes site geological survey and site pressure test, calculation of the bearing capacity, specific length, spacing and quantity of the steel pipe sleeves;the gable positions and size of the undersides of the prefabricated cover plates are determined according to the quantity and spacing of the steel pipe sleeves;the construction is convenient, can greatly reduce the working surface and engineering quantity, shorten the construction time;and can effectively protect the safety of the pipeline at the same time.

Description

Technical Field

[0001] This invention belongs to the field of underground structure technology, specifically relating to a construction method for a rapid, trenchless underground pipeline cover protection structure. Background Technology

[0002] Under the new circumstances, urban construction in some large and medium-sized cities has become increasingly sophisticated. The mainstream of municipal road construction has gradually shifted from building new roads to upgrading and transforming existing municipal roads. Retaining and utilizing existing pipelines is an innovative manifestation of achieving sustainable development strategies, promoting green building construction, low-carbon city development, and smart city formation. It is an organic combination of green new technologies with various social, environmental, and humanistic factors under the background of the new era.

[0003] As an important component of municipal road renovation, cover plate protection plays a vital role in the construction of green and low-carbon cities. It enables the use of existing pipeline facilities during urban renovation, reducing the impact of construction and playing a significant role in promoting civilized urban construction and reducing environmental pollution.

[0004] Current cover plate protection methods primarily involve deep excavation and cast-in-place construction, which is time-consuming and has a large impact area. Generally, excavation is based on the pipeline's burial depth, reaching below the pipeline's bottom elevation before the cover plate supports are poured. The cover plate is then laid after the concrete reaches the required strength. Only after the cover plate construction is complete can road construction proceed according to regulations. Excavation requires a certain amount of construction space and easily disturbs the surrounding soil, causing pipeline movement or misalignment. Using support concrete requires approximately two weeks to solidify, during which time protective measures must be taken around the pipeline to prevent damage, consuming significant manpower and resources, and involves numerous unstable factors. Summary of the Invention

[0005] The purpose of this invention is to provide a construction method for a rapid, trenchless underground pipeline cover protection structure that can effectively protect underground pipelines.

[0006] The present invention provides a construction method for a rapid, trenchless cover plate protection structure for underground pipelines. The structure includes: several steel pipe sleeves, a precast pipeline cover plate, and a double-layer geotextile for waterproofing, with a highly compressible granular material filling the space between the two layers of geotextile. The steel pipe sleeves are vertically arranged on both sides of the pipeline to be protected, serving as the supporting foundation for the precast pipeline cover plate. A downward-facing tenon is provided on the lower side of the precast pipeline cover plate, corresponding to the position of the steel pipe sleeve. This tenon matches the upper opening size of the steel pipe sleeve and is embedded in the upper opening of the steel pipe sleeve to fix its position. The double-layer geotextile and the highly compressible granular material are placed between the steel pipe sleeves on both sides of the pipeline and between the pipeline and the precast pipeline cover plate to fix it and prevent leakage. The specific construction steps are as follows: (1) On-site geological survey and on-site pressure test, calculate the bearing capacity of steel pipe sleeves and their specific length, spacing and quantity; (2) Precast cover plates, determine the thickness of the cover plates according to the actual needs of the protected pipeline; determine the position and size of the tenon on the underside of the cover plate according to the number and spacing of the steel pipe sleeves; (3) After the concrete cover plate is prefabricated, the road in the pipeline area is excavated. A certain thickness (e.g., 100-200 mm) of original soil is retained on the top of the pipe. After excavating to the design elevation, hydraulic machinery is used to construct the steel pipe sleeve, which is vertically pressed into the soil. The upper part of the steel sleeve is controlled to be exposed 200-300 mm above the soil layer. (4) After the steel sleeve construction is completed, two layers of geotextile are laid on the upper part of the protected pipeline, with the steel sleeves on both sides as the boundary, and high compressibility granular material is filled in the two layers of geotextile. (5) Lay the precast concrete cover plates in sequence, insert the tenon into the upper opening of the steel pipe sleeve, and check the settlement and stability of the precast concrete cover plates. (6) After confirming that the precast cover plate is stable, backfill the soil and start the construction of the upper road structure layer, and then proceed further.

[0007] The bearing capacity, specific length, spacing, and quantity of the steel pipe sleeves are determined based on the results of on-site geological surveys and on-site pressure tests. Typically, the steel pipe sleeves are evenly spaced on both sides of the pipeline, with a spacing of 0.8-1.2m. The length of the steel pipe sleeves is 4-6m, the pipe diameter d is 250-300 mm, and the wall thickness is 2-3mm.

[0008] The prefabricated cover plate has a thickness of 200-350 mm.

[0009] The diameter of the convex tenon on the lower side of the prefabricated cover plate is 240-280 mm, and the height is 250-350 mm.

[0010] The double-layer geotextile and the filling high-compressibility granular material have a thickness of 20-40 mm.

[0011] The highly compressible particulate material may specifically be: polystyrene particles, rubber particles, polyethylene particles, etc.

[0012] The construction method of the cover plate protection structure of the present invention can greatly reduce the construction work area and the amount of construction work, thus greatly shortening the construction time; at the same time, it will not affect the pipeline project and can effectively protect the pipeline safety; that is, the present invention has the advantages of perfect function, fast construction, minimal impact, green environmental protection, energy saving and high efficiency. Attached Figure Description

[0013] Figure 1 This is a cross-sectional view of the cover plate protective structure of the present invention.

[0014] Figure 2 This is a plan view of the cover plate foundation.

[0015] Figure 3 This is a plan view of the cover plate.

[0016] The numbers in the diagram are: 1 for precast cover plate, 2 for steel pipe sleeve, 3 for tenon, 4 for impermeable geotextile (two layers, filled with highly compressible granular material), 5 for road structure layer, and 6 for pipeline. Implementation

[0017] Example

[0018] The example cover plate is for protecting a 1000mm diameter water supply pipe within the green belt on both sides of the road, with a total protection range of approximately 450m. The steel pipe sleeves are d300mm thick with a wall thickness of 2mm, and are distributed at 1.0m intervals in the planar layout. The minimum distance between the steel sleeve and the existing water supply pipe is 1500mm (≥D+H, where H is the distance from the bottom of the precast cover plate to the top of the pipe). The sleeve length is 6m. The precast cover plate is 350mm thick, reinforced with double-layered, bidirectional d18@150 steel bars, using C30 concrete, with a 220mm diameter tenon and a 300mm height, and distributed at the same interval as the steel sleeve, with H=500mm. From top to bottom, the cover plate consists of geotextile-wrapped granules and the original soil covering the pipe.

[0019] The solution achieves the following force transmission path: the vehicle load and soil load of the ground construction access road are transmitted to the concrete cover plate, and then through the concrete cover plate to the supporting steel sleeves on both sides. The steel sleeves use the friction of the soil to resist the vehicle load and soil load transmitted from the ground.

[0020] The tenon is embedded in the steel sleeve to resist the shear force generated by horizontal movement, preventing the cover plate from disengaging from the sleeve and causing the protective structure to fail. Highly compressible granules are filled under the cover plate to buffer and isolate the deflection deformation under normal use, preventing pressure from being transmitted to the water supply pipe. At the same time, the granular filler can also effectively prevent the soil around the pipeline from heaving.

[0021] Because steel pipe sleeves are used as the foundation, concrete cover slabs are prefabricated. The construction of the cover slab protection structure, from ground excavation to cover slab laying and backfilling, can be completed in 2-4 days, shortening the construction cycle by 3-5 days compared to the existing construction cycle; it can seamlessly connect with subsequent road construction and achieve rapid replacement of temporary roads.

Claims

1. A construction method for a rapid, trenchless underground pipeline cover protection structure, characterized in that, The underground pipeline cover protection structure includes several steel pipe sleeves, a precast cover plate, and a double-layer geotextile for seepage prevention, with highly compressible granular material filling the space between the two layers of geotextile. The steel pipe sleeves are vertically arranged on both sides of the pipeline to be protected, serving as the supporting foundation for the precast pipeline cover plate. A downward-facing tenon is provided on the lower side of the precast pipeline cover plate, corresponding to the position of the steel pipe sleeve. This tenon matches the upper opening size of the steel pipe sleeve and is embedded in the upper opening of the steel pipe sleeve to fix its position. The double-layer geotextile and the highly compressible granular material are placed between the steel pipe sleeves on both sides of the pipeline and between the pipeline and the precast pipeline cover plate to fix it and prevent leakage. The specific construction steps are as follows: (1) On-site geological survey and on-site pressure test, calculate the bearing capacity of steel pipe sleeves and their specific length, spacing and quantity; (2) Precast cover plates, determine the thickness of the cover plates according to the actual needs of the protected pipeline; determine the position and size of the tenon on the underside of the cover plate according to the number and spacing of the steel pipe sleeves; (3) After the concrete cover plate is prefabricated, the road in the pipeline area is excavated and the original soil with a thickness of 100-200 mm is retained above the pipeline. After excavating to the design elevation, hydraulic machinery is used to vertically press the steel pipe sleeve into the soil, and the upper part of the steel pipe sleeve is exposed 200-300 mm above the soil layer. (4) After the steel sleeve construction is completed, two layers of geotextile are laid on the upper part of the pipeline with the steel sleeves on both sides as the boundary, and high compressibility granular material is filled in the two layers of geotextile. (5) Lay the precast concrete cover plates in sequence, insert the tenon into the upper opening of the steel pipe sleeve, and check the settlement and stability of the precast concrete cover plates. (6) After confirming that the precast cover plate is stable, backfill the soil and start construction of the upper road structure layer.

2. The construction method according to claim 1, characterized in that, The steel pipe sleeves are evenly spaced, with a spacing of 0.8-1.2m; the length of the steel pipe sleeve is 4-6m, the pipe diameter is 250-300 mm, and the wall thickness is 2-3mm.

3. The construction method according to claim 1, characterized in that, The thickness of the prefabricated cover plate is 200-350 mm.

4. The construction method according to claim 1, characterized in that, The diameter of the convex tenon on the lower side of the prefabricated cover plate is 240-280 mm, and the height is 250-350 mm.

5. The construction method according to claim 1, characterized in that, The double-layer geotextile and the filling high-compressibility granular material have a thickness of 20-40 mm.

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