Fault-adaptive buried pipeline structure based on soil-plastic ball mixed backfill
By using a soil-plastic ball hybrid backfill structure, the problem of poor deformation coordination of buried pipelines in active fault areas was solved. HDPE plastic balls were mixed with backfill soil to form a flexible energy-absorbing buffer layer, which improved deformation coordination and enhanced structural safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- POWERCHINA ZHONGNAN ENG
- Filing Date
- 2025-06-27
- Publication Date
- 2026-07-14
Smart Images
Figure CN224497964U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of buried pipeline technology, and in particular to a fault-adaptive buried pipeline structure based on soil-plastic ball mixed backfill. Background Technology
[0002] Buried pipelines, as an important component of national infrastructure, are widely used in fields such as water conservancy and hydropower, water supply and drainage, natural gas transportation, oil transportation, and industrial fluid transportation. With the continuous development of infrastructure construction, pipelines are increasingly passing through areas with complex geological structures, especially in areas with active faults, landslide zones, and weak interlayers. Uneven settlement or displacement of the foundation places higher demands on the deformation coordination of the pipeline structure.
[0003] In fault-prone areas, the relative displacement of strata caused by tectonic movements leads to significant tensile, compressive, shear, and bending stresses on buried pipelines. In severe cases, this can cause pipeline rupture or complete functional failure, resulting in significant safety hazards and economic losses. Traditional designs often adapt to fault deformation by enhancing the pipeline's own strength, installing flexible joints, or introducing local flexible sections. However, these measures are often limited in practical engineering due to high costs, limited deformation bearing capacity, or complex construction processes.
[0004] Regarding backfill structures, existing projects generally use conventional backfill materials such as sand, gravel, and cohesive soil. While these materials are easy to construct, they cannot effectively mitigate stress concentration between the pipeline and the surrounding soil under fault displacement. Furthermore, some studies and engineering examples have attempted to construct flexible buffer zones using energy-absorbing materials such as lightweight soil and EPS boards to improve the deformation compatibility between the pipeline and the foundation. However, these materials often suffer from unstable mechanical properties, poor long-term durability, or poor construction adaptability, making large-scale engineering application difficult under complex geological conditions. Utility Model Content
[0005] The purpose of this invention is to provide a fault-adaptive buried pipeline structure based on soil-plastic ball mixed backfill, which solves the problems of poor deformation coordination and easy damage of buried pipelines in active fault areas in the prior art.
[0006] To achieve the above objectives, this utility model provides a fault-adaptive buried pipeline structure based on a soil-plastic ball mixed backfill, including a buried pipeline body and a surrounding backfill layer. The surrounding backfill layer is arranged around the buried pipeline body and includes an upper backfill layer, a middle backfill layer, and a lower backfill layer. The lower backfill layer, the middle backfill layer, and the upper backfill layer are all composed of a mixture of plastic balls and backfill soil.
[0007] Preferably, the plastic ball is made of HDPE high-density polyethylene material, and the inside of the plastic ball has a honeycomb structure.
[0008] Preferably, the mixing ratio of the plastic ball to the backfill soil is 1:5 to 1:10.
[0009] Preferably, the total volume of the plastic ball adheres to 9.1-16.7% of the surrounding backfill layer.
[0010] Preferably, the upper backfill layer is located between the top of the buried pipeline body and the ordinary backfill soil, and the plastic balls arranged in the upper backfill layer are sparsely distributed, with the plastic balls having a diameter of 15-20cm.
[0011] Preferably, the intermediate backfill layer is disposed between the top and the waist of the buried pipeline body, and the plastic balls arranged in the intermediate backfill layer have a diameter of 10-15cm.
[0012] Preferably, the lower backfill layer is disposed between the pipe waist of the buried pipeline body and the sand cushion layer, the lower part of the sand cushion layer is undisturbed soil, and the plastic balls arranged in the lower backfill layer have a diameter of 5-10cm.
[0013] Therefore, the fault-adaptive buried pipeline structure based on soil-plastic ball mixed backfill, as described above, has the following beneficial effects:
[0014] (1) The plastic ball-soil hybrid structure has good elastic buffering and controllable damage performance, which significantly improves the deformation coordination between the pipeline and the foundation.
[0015] (2) During the fault displacement process, the mixed backfill layer can release local stress concentration and reduce the risk of structural damage.
[0016] (3) The construction process is simple, the materials are widely available, and it is suitable for various types of buried pipeline projects. It has good engineering adaptability and promotion value.
[0017] (4) The type, size and dosage of plastic balls in the backfill structure can be flexibly adjusted according to the project requirements to achieve adjustable performance and controllable design.
[0018] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0019] Figure 1 This is a structural schematic diagram of an embodiment of the fault-adaptive buried pipeline structure based on soil-plastic ball mixed backfill of this utility model;
[0020] Figure 2 This is a schematic diagram of the plastic ball structure of the fault-adaptive buried pipeline structure based on soil-plastic ball mixed backfilling according to this utility model.
[0021] Figure Labels
[0022] 1. Buried pipeline body; 2. Upper backfill layer; 3. Middle backfill layer; 4. Lower backfill layer; 5. Plastic ball; 6. Backfill soil; 7. Sand cushion layer. Detailed Implementation
[0023] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments.
[0024] Unless otherwise defined, the technical or scientific terms used in this utility model shall have the ordinary meaning understood by one of ordinary skill in the art to which this utility model pertains. The terms "first," "second," and similar terms used in this utility model do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.
[0025] Example
[0026] Please see Figures 1-2 This invention provides a fault-adaptive buried pipeline structure based on a soil-plastic ball hybrid backfill, comprising a buried pipeline body 1 and a surrounding backfill layer. The surrounding backfill layer is arranged along the pipeline axis around the buried pipeline body 1, constructing a "flexible-energy-dissipating" synergistic buffer structure. During fault activity or earthquake-induced foundation displacement, the soil-plastic ball hybrid layer can release some energy through microscopic compression, slippage, or controlled destruction, while providing deformation clearance space and reducing local stress concentration, thereby effectively improving the pipeline's deformation adaptability, extending its service life, and enhancing overall operational safety. The surrounding backfill layer includes an upper backfill layer 2, a middle backfill layer 3, and a lower backfill layer 4, all of which are composed of a mixture of plastic balls 5 and backfill soil 6.
[0027] The plastic balls 5 are made of high-density polyethylene (HDPE), which has good elastic modulus and controllable crushing performance. The diameter of the plastic balls 5 is generally 20-300mm, depending on the specific project requirements. The volume of the plastic balls 5 can vary. They are mixed using an on-site mixer or manually to ensure uniform distribution and avoid concentrated accumulation. The balls require a certain wall thickness to provide good compressive strength. If necessary, a rough texture can be added to the surface of the balls to enhance the frictional resistance between them and the soil, improving overall lateral confinement performance.
[0028] The plastic sphere 5 has a honeycomb structure inside, which has high mechanical efficiency and combines energy absorption and load-bearing capacity, further improving the sphere's strength and energy absorption efficiency. The surrounding backfill layer is arranged around the pipeline, forming a flexible energy-dissipating zone. When fault displacement causes relative deformation of the foundation, the pipeline applies stress to the surrounding backfill soil, causing the plastic sphere 5 to deform under pressure or break, thus buffering and absorbing energy, releasing localized stress concentration, and improving the pipeline's adaptability under complex deformation fields.
[0029] The mixing ratio of backfill soil 6 and plastic balls 5 is determined according to the volume ratio, plastic balls: backfill soil = 1:5 to 1:10.
[0030] The upper backfill layer 2 is located between the top of the buried pipeline body 1 and the ordinary backfill soil 6. The plastic balls 5 arranged in the upper backfill layer 2 are sparsely distributed, and the diameter of the plastic balls 5 is 15-20cm.
[0031] The intermediate backfill layer 3 is set between the top and the waist of the buried pipeline body 1. The plastic balls 5 arranged in the intermediate backfill layer 3 have a diameter of 10-15cm and facilitate energy transfer.
[0032] The lower backfill layer 4 is placed between the pipe waist of the buried pipeline body 1 and the sand cushion layer 7. The bottom of the sand cushion layer 7 is filled with undisturbed soil. The plastic balls 5 arranged in the lower backfill layer 4 have a diameter of 5-10cm. Through layered filling and light compaction, the integrity and buffering performance of the mixed backfill layer are ensured. If necessary, plastic balls 5 with different volume ratios or particle sizes can be set in different parts to adapt to different geological deformation requirements. The total volume ratio of the balls is recommended to be 9.1-16.7%, i.e., 1 / (1+10)-1 / (1+5), to avoid excessively reducing the soil density.
[0033] The soil-plastic ball construction method includes the following steps:
[0034] (1) Preparation of mixed materials: Mix the plastic balls 5 with the soil on site according to the design ratio. If necessary, a batch can be pre-mixed in the trench area for later use.
[0035] (2) Layered backfilling and compaction: The mixed material is filled in layers with a thickness not exceeding 30cm on both sides and top of the pipe, divided into upper, middle and lower layers. Different layers use plastic balls of different densities and sizes 5. Low-pressure static roller or vibratory rammer is used for compaction, but it must be ensured that construction disturbance does not damage the structural integrity of the plastic balls.
[0036] (3) Conventional soil backfilling: Conventional soil is backfilled in layers above the soil-plastic ball mixed layer, with a thickness of not less than 30cm, as a structural protective layer.
[0037] (4) Protection and monitoring measures: Displacement monitoring sensors can be installed in key areas for later fault activity response analysis and maintenance assessment.
[0038] Therefore, this utility model adopts the above-mentioned fault-adaptive buried pipeline structure based on soil-plastic ball mixed backfill. The plastic ball-soil mixed structure has good elastic buffering and controllable failure performance, significantly improving the deformation coordination between the pipeline and the foundation. During fault displacement, the mixed backfill layer can release local stress concentration, reduce the risk of structural failure, and extend the service life of the pipeline. The construction process is simple, the materials are widely available, and it is suitable for various types of buried pipeline projects, demonstrating good engineering adaptability and promotional value.
[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solution of this utility model, and these modifications or equivalent substitutions cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of this utility model.
Claims
1. A fault-adaptive buried pipeline structure based on soil-plastic ball hybrid backfill, characterized in that: It includes a buried pipeline body and a surrounding backfill layer. The surrounding backfill layer is arranged around the buried pipeline body and includes an upper backfill layer, a middle backfill layer and a lower backfill layer. The lower backfill layer, the middle backfill layer and the upper backfill layer are all composed of a mixture of plastic balls and backfill soil.
2. The fault-adaptive buried pipeline structure based on soil-plastic ball hybrid backfill as described in claim 1, characterized in that: The plastic ball is made of HDPE high-density polyethylene material, and the inside of the plastic ball has a honeycomb structure.
3. The fault-adaptive buried pipeline structure based on soil-plastic ball hybrid backfill as described in claim 2, characterized in that: The mixing ratio of the plastic ball to the backfill soil is 1:5 to 1:
10.
4. The fault-adaptive buried pipeline structure based on soil-plastic ball hybrid backfill as described in claim 3, characterized in that: The total volume of the plastic spheres accounts for 9.1-16.7% of the surrounding backfill layer.
5. The fault-adaptive buried pipeline structure based on soil-plastic ball hybrid backfill as described in claim 4, characterized in that: The upper backfill layer is located between the top of the buried pipeline body and the ordinary backfill soil. The plastic balls arranged in the upper backfill layer are sparsely distributed, and the diameter of the plastic balls is 15-20cm.
6. The fault-adaptive buried pipeline structure based on soil-plastic ball hybrid backfill as described in claim 5, characterized in that: The intermediate backfill layer is located between the top and the middle of the buried pipeline body, and the plastic balls arranged in the intermediate backfill layer have a diameter of 10-15cm.
7. The fault-adaptive buried pipeline structure based on soil-plastic ball hybrid backfill as described in claim 6, characterized in that: The lower backfill layer is located between the waist of the buried pipeline body and the sand cushion layer. The lower part of the sand cushion layer is undisturbed soil. The plastic balls arranged in the lower backfill layer have a diameter of 5-10cm.