Foam concrete filling structure for large-diameter oil and gas pipeline tunnel
By adopting foam concrete filling structure in oil and gas pipeline tunnels, the problems of low strength and long construction cycle of traditional filling materials are solved, and the effects of convenient construction, cost reduction and service life are achieved.
Patent Information
- Application Number
- CN202422587765.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-25
- Publication Date
- 2025-08-08
- Estimated Expiration
- 2034-10-25
AI Technical Summary
Traditional oil and gas pipeline filling materials such as water sand filling have problems such as low strength, long construction cycle, and difficult operation and maintenance, and are highly repaired and prone to environmental pollution.
The foam concrete filling structure is adopted, including the foam concrete filling layer, the foam concrete structure layer and the foam concrete reinforcement layer in the tunnel from bottom to top. By controlling the layer thickness and strength gradient, partition channels are set up, and the fluidity and strength adjustability of foam concrete are utilized to achieve convenient construction and reduce the load burden on the tunnel.
It improves the protection effect of the pipeline, reduces the construction cost, reduces the superposition of pipeline vibration, reserves maintenance channels, extends service life, and reduces the risk of cracking.
Smart Images
Figure CN223203855U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of pipeline tunnel filling, and mainly to a foam concrete filling structure for large-diameter oil and gas pipeline tunnels. Background Art
[0002] After the installation of oil and gas pipelines, they are usually fully covered with a protective filling system to prevent deformation and even gas leaks caused by external environmental factors such as temperature and pressure during later operations. For a long time, water-sand filling has been the main method used for filling newly built or abandoned oil and gas pipelines both domestically and internationally. However, traditional water-sand filling suffers from low strength and long construction cycles. Furthermore, if pipeline defects develop during later operations, the filling material must be repeatedly transported and refilled during maintenance. This requires the repeated transport of large amounts of water, sand, and other filling materials, resulting in high maintenance costs and environmental pollution.
[0003] Foam concrete is a new type of lightweight material with the characteristics of lightness and good fluidity. Its strength and dry density can be adjusted according to the needs of the project. At the same time, industrial solid waste such as slag and fly ash can be used as auxiliary admixtures to be compounded with cement, which has the advantages of high strength and low cost. Foam concrete can be transported to the filling area by pipeline pump or gravity flow. Its construction is convenient and suitable for various complex construction environments. It can be used as a new type of filling material in oil and gas pipeline filling. At present, foam concrete has been widely used in municipal pipeline backfill and narrow foundation pit fertilizer trough backfill projects, but there is no precedent for its use in filling large-diameter oil and gas pipeline tunnels. Therefore, it is necessary to propose a foam concrete filling structure for large-diameter pipeline tunnels. Utility Model Content
[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of this application is to provide a foam concrete filling structure for large-diameter oil and gas pipeline tunnels, aiming to solve the problems of low strength, long construction period, and difficult operation and maintenance existing in traditional oil and gas pipeline fillings.
[0005] The technical solution of this application is as follows:
[0006] The present application provides a foam concrete filling structure for a large-diameter oil and gas pipeline tunnel, comprising a tunnel, wherein the tunnel comprises, from bottom to top, a foam concrete filling layer, a foam concrete structural layer, and a foam concrete strengthening layer;
[0007] The central area of the foamed concrete strengthening layer is provided with a channel which separates the foamed concrete strengthening layer and exposes the foamed concrete structural layer;
[0008] The foam concrete filling layer, foam concrete structural layer and foam concrete strengthening layer are made of foam concrete;
[0009] A pipe is provided in the foam concrete filling layer, and a pipe is provided on each of the two partitioned sides of the foam concrete strengthening layer.
[0010] This application uses foam concrete to fill large-diameter oil and gas pipeline tunnels. By utilizing the good fluidity, density and strength adjustability of foam concrete, convenient construction in complex tunnel environments can be achieved. Its lightweight characteristics can provide good filling and protection for the pipeline while reducing the bearing burden of the tunnel, which is conducive to maintaining tunnel stability.
[0011] Furthermore, the distance between the top surface of the foam concrete reinforcement layer and the tunnel ceiling is no less than 2 meters, and the channel separation distance is no less than 1.2 times the diameter of the pipe and no less than 0.5 meters. By controlling the clearance distance within the tunnel, this application reserves sufficient space and controls the filling level, thereby improving the stability of the filling structure. By controlling the separation distance, the cumulative effect of pipeline vibration during parallel pipeline operation is weakened, while also reducing the adverse effects of parallel pipelines on each other.
[0012] Furthermore, the ratio of the pipe diameter to the tunnel diameter is 0.3-0.42:1, the ratio of the thickness of the foamed concrete filling layer to the pipe diameter is 1.15-1.4:1, and the ratio of the thickness of the foamed concrete reinforcement layer to the pipe diameter is 1.05-1.10:1. In this application, by controlling the thickness of the foamed concrete filling layer and the foamed concrete reinforcement layer, the pipe is guaranteed to be filled and protected. By controlling the ratio of the pipe and tunnel diameters, tunnel efficiency is maintained while ensuring sufficient pipe throughput. This ratio reduces the amount of raw materials used while maintaining sufficient protective performance of the filling structure.
[0013] Furthermore, the thickness of the foamed concrete structure layer is 0.5-0.8 m. By controlling the foamed concrete structure layer to have an appropriate thickness, the present application can ensure that the foamed concrete structure layer plays a sufficient vibration isolation role, preventing the vibration transmission of the upper and lower pipes from affecting the normal use of the pipes.
[0014] Furthermore, the compressive strength of the foamed concrete filling layer is 1.5-2 MPa, the compressive strength of the foamed concrete structural layer is 2-3 MPa, and the compressive strength of the foamed concrete reinforcement layer is 3-5 MPa. By combining the gradient strengths of the foamed concrete filling layer, the foamed concrete structural layer, and the foamed concrete reinforcement layer, the overall lightweight filling structure is maintained while meeting the requirements for filling protection, effectively extending the service life of the filling structure.
[0015] Furthermore, fibers are provided in the foam concrete reinforcement layer, and the distribution of the fibers acts as reinforcement, thereby improving the protective performance of the foam concrete reinforcement layer.
[0016] Furthermore, the length of the fiber is 6-14 mm, the diameter of the fiber is 7-15 μm, and the aspect ratio of the fiber is 1000-3000:1.
[0017] Furthermore, the flexural strength of the foam concrete reinforcement layer is 1.2-2 MPa.
[0018] Furthermore, a pipeline base is provided below the pipeline.
[0019] Furthermore, the anti-floating stability coefficient of the tunnel K satisfy:
[0020] ;
[0021] M 1 is the deadweight of the foam concrete filling layer, M 2 is the deadweight of the foamed concrete structural layer, M 3 is the deadweight of the foamed concrete reinforcement layer, M p is the dead weight of the pipeline, M q is the deadweight of the pipeline base, V is the volume of the tunnel, ρ is the density of water, g is the acceleration due to gravity.
[0022] Beneficial effects: Through the foam concrete filling structure for large-diameter oil and gas pipeline tunnels provided by this application, the foam concrete filling layer can well protect the pipelines therein, and by setting a partition channel in the foam concrete reinforcement layer, the superposition effect of parallel pipeline vibration is reduced, the filling cost is reduced, and a maintenance channel is reserved for the operation period. The foam concrete structural layer can provide support for the channel and at the same time play a vibration isolation role to prevent the vibration transmission of the upper and lower pipelines from affecting the normal use of the pipeline. Through the setting of this application, the pipelines are distributed in an inverted T-shape in the filling structure, which can reduce the vibration effect between the pipelines and reduce the risk of cracking of the filling structure. At the same time, it can maintain a sufficient safe clearance between the pipelines to avoid the impact of pipeline vibration, deformation and even explosion shock on adjacent pipelines. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 This is a schematic structural diagram of the foam concrete filling structure used in large-diameter oil and gas pipeline tunnels in this application.
[0024] Explanation of reference numerals: 1. Foam concrete filling layer; 2. Foam concrete structural layer; 3. Foam concrete strengthening layer; 31. Passageway. DETAILED DESCRIPTION
[0025] This application provides a foam concrete filling structure for large-diameter oil and gas pipeline tunnels. To clarify the purpose, technical solutions, and effects of this application, the application is further described below. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.
[0026] At present, the largest diameter oil and gas pipelines in China are mainly 1016mm and 1219mm. If the diameter of the pipeline is further increased, it will bring technical challenges to long-distance pipeline transportation and long-term use, especially traditional water-sand filling, which is not only difficult to construct but also difficult to provide adequate protection.
[0027] Regarding this issue, Figure 1 As shown, the present application provides a foam concrete filling structure for a large-diameter oil and gas pipeline tunnel, comprising a tunnel, wherein, from bottom to top in the tunnel, it comprises a foam concrete filling layer 1, a foam concrete structural layer 2, and a foam concrete strengthening layer 3;
[0028] A channel 31 is provided in the central area of the foam concrete reinforcement layer 3 to separate the foam concrete reinforcement layer 3 and expose the foam concrete structural layer 2;
[0029] The material of the foam concrete filling layer 1, the foam concrete structural layer 2 and the foam concrete strengthening layer 3 is foam concrete;
[0030] A pipe is provided in the foam concrete filling layer 1 , and a pipe is provided on each of the two partitioned sides of the foam concrete strengthening layer 3 .
[0031] This application uses foamed concrete to fill large-diameter oil and gas pipeline tunnels. Leveraging foamed concrete's excellent fluidity, density, and adjustable strength, it facilitates construction in complex tunnel environments. Its lightweight construction provides excellent filling and protection for the pipelines while reducing the tunnel's load, contributing to tunnel stability. By controlling the distribution of pipelines within the tunnel, the impact of vibration between pipelines can be reduced, mitigating the risk of cracking.
[0032] Among them, the provided foam concrete filling structure can effectively protect large-diameter oil and gas pipelines. The diameter of the oil and gas pipeline can reach 1422mm, which is the largest diameter oil and gas pipeline in the country. It can ensure the long-term use of large-diameter oil and gas pipelines. Moreover, this filling structure is not only suitable for large diameters, but can also meet the use requirements of small-diameter oil and gas pipelines.
[0033] In a specific embodiment of the present application, the distance between the top surface of the foam concrete reinforcement layer 3 and the top of the tunnel is not less than 2m, and the partition distance of the channel 31 is not less than 1.2 times the diameter of the pipe and not less than 0.5m.
[0034] Specifically, by controlling the clearance distance between the foam concrete reinforcement layer 3 and the tunnel top, sufficient space is reserved for later maintenance and repair or the installation of other devices. In addition, the filling level in the tunnel can be controlled, reducing the impact of temperature changes on the combination of the filling structure and the tunnel, and improving the stability of the filling structure. By providing a partition channel 31 in the foam concrete reinforcement layer 3, the amount of foam concrete filling in the foam concrete reinforcement layer 3 can be saved, reducing costs, maintaining a safety distance of not less than 0.5m, and reserving a manual maintenance channel for pipeline operation. Moreover, by maintaining a partition distance of not less than 1.2 times the diameter of the pipeline, the superimposed effect of pipeline vibration during the operation of parallel pipelines can be effectively weakened, while reducing the adverse effects of parallel pipelines on each other, reducing the risk of interlayer separation caused by resonance, and also helping to increase the service life of the filling structure.
[0035] Through the arrangement of the present application, the pipelines are distributed in an inverted T-shape in the filling structure, which can maintain a sufficient safe clearance between the pipelines and avoid the impact of pipeline vibration, deformation and even explosion impact on adjacent pipelines.
[0036] In a specific embodiment of the present application, the ratio of the pipe diameter to the tunnel diameter is 0.3-0.42:1, the ratio of the thickness of the foamed concrete filling layer 1 to the pipe diameter is 1.15-1.4:1, and the ratio of the thickness of the foamed concrete reinforcement layer 3 to the pipe diameter is 1.05-1.10:1. By controlling the thickness of the foamed concrete filling layer 1 and the foamed concrete reinforcement layer 3, the pipe is guaranteed to be filled and protected. By controlling the ratio of the pipe and tunnel diameters, tunnel efficiency is maintained while ensuring sufficient pipe throughput. This ratio reduces the amount of raw materials used while maintaining adequate protective properties of the filling structure.
[0037] In a specific embodiment of the present application, the thickness of the foam concrete structural layer 2 is 0.5-0.8m. Specifically, if the thickness of the foam concrete structural layer 2 is too low, the vibration isolation effect of the foam concrete structural layer 2 is not obvious, and if the thickness is too high, the foam concrete structural layer 2 needs to be poured in layers to meet the required thickness, making it difficult to control the pouring uniformity in the vertical direction during the pouring process, and prone to stratification with the upper layer being light and the lower layer being heavy, affecting the integrity of the foam concrete structural layer 2 and reducing its vibration reduction effect. By controlling the foam concrete structural layer 2 to an appropriate thickness, the present application can ensure that the foam concrete structural layer 2 plays a sufficient vibration isolation role and prevent the vibration transmission of the upper and lower pipes from affecting the normal use of the pipes. In addition, the provided foam concrete structural layer 2 can also facilitate the layered pouring construction needs of the filling structure, can serve as a temporary construction platform for the foam concrete reinforcement layer 3, and provide support for the maintenance channel 31 during the operation period.
[0038] In this application, the foamed concrete filling layer 1, foamed concrete structural layer 2, and foamed concrete reinforcement layer 3 are made of foamed concrete. Using foamed concrete for tunnel filling not only takes advantage of its excellent construction performance but also reduces filling costs. The filling cost and strength of foamed concrete are directly related to its bubble volume ratio: a higher bubble volume ratio results in lower strength and lower filling costs, and vice versa. Therefore, during filling, it is important to fully utilize the density and strength adjustability of foamed concrete, rationally configuring strength and wet density according to the needs of each layer to minimize filling costs and optimize filling performance.
[0039] In a specific embodiment of the present application, the wet density of the foamed concrete of the foamed concrete filling layer 1 is 0.8-1.0 kN / m 3 The wet density of the foamed concrete in the foamed concrete structure layer 2 is 1.0~1.2kN / m 3 The wet density of the foamed concrete in the foamed concrete reinforcement layer 3 is 1.1~1.3kN / m 3 By controlling the foam concrete filling layer 1, the foam concrete structural layer 2 and the foam concrete reinforcement layer 3 at appropriate wet densities, the required strength requirements can be easily met.
[0040] More specifically, the compressive strength of the foamed concrete filling layer 1 is 1.5-2 MPa, the compressive strength of the foamed concrete structural layer 2 is 2-3 MPa, and the compressive strength of the foamed concrete reinforcement layer 3 is 3-5 MPa. Because foamed concrete is used for filling, the compressive strength of each layer in the filling structure is primarily the compressive strength at 28 days.
[0041] In this application, the foam concrete of the foam concrete filling layer 1 must have a certain strength to prevent the foam concrete from being damaged due to vibration or deformation of the pipe; and the strength of the foam concrete of the foam concrete structural layer 2 is appropriately improved. On the one hand, it can serve as the function of the middle vibration insulation layer. On the other hand, the erection of the side formwork of the foam concrete strengthening layer 3 is based on the hardening of the foam concrete of the foam concrete structural layer 2. The pipes and formwork required for the construction of the foam concrete strengthening layer 3 are all transported through the foam concrete structural layer 2 (also as the need to carry the operation and maintenance channel). Therefore, it needs to have higher strength performance to avoid damage to the foam concrete of the foam concrete structural layer 2 caused by vibration of the upper and lower pipes or the traffic of vehicles during operation; the pipes of the foam concrete strengthening layer 3 have a lower coverage than the foam concrete filling layer 1, so it also requires higher compressive strength to ensure sufficient fixing effect.
[0042] By varying the strengths of the foamed concrete filling layer 1, foamed concrete structural layer 2, and foamed concrete reinforcement layer 3, the filling structure can achieve differentiated properties, reducing the mutual influence of pipeline vibration. By achieving gradient strength coordination, the overall lightweight filling structure can be maintained while meeting the requirements for filling protection, effectively extending the service life of the filling structure.
[0043] In this application's infill structure design, the lower pipe is completely encased in a foamed concrete infill layer 1. The pipe, foamed concrete, and tunnel segment support structure form a single, integrated structure, effectively offsetting the effects of vibration or deformation caused by pipe operation. However, the foamed concrete reinforcement layer 3, limited by tunnel clearance and the design requirements of the maintenance passage 31, has a limited thickness on the free-facing surface. This makes the foamed concrete more susceptible to cracking under the long-term operating temperatures and pressures of the pipe, posing a risk of oil and gas leakage. Therefore, further reinforcement is required.
[0044] To address the above issues, in one specific embodiment of the present application, fibers are incorporated into the foamed concrete reinforcement layer 3. The fibers are selected from the group consisting of polypropylene fibers, basalt fibers, coconut shell fibers, and sisal fibers. In this application, by incorporating a certain amount of fibers into the foamed concrete of the foamed concrete reinforcement layer 3, a good reinforcement effect is achieved, effectively improving the tensile strength of the foamed concrete. This fully offsets the deformation energy generated by the pipeline under long-term temperature and pressure during operation, thus preventing damage such as cracking and shedding of the foamed concrete reinforcement layer 3 caused by pipeline vibration and deformation during operation.
[0045] The fiber content in the foamed concrete of the foamed concrete reinforcement layer 3 is 0.4%-0.8%.
[0046] Furthermore, the fiber length is 6-14 mm, the fiber diameter is 7-15 μm, and the fiber aspect ratio is 1000-3000:1. In the present application, by using fibers within this aspect ratio range, the fibers are well dispersed when mixed with the foamed concrete slurry and are less likely to clump or clump. The evenly distributed fibers can facilitate the formation of a three-dimensional interlaced reinforcement system, improve the ductility and tensile strength of the foamed concrete, and enhance the foamed concrete's crack resistance and impact resistance under pipeline vibration, deformation, or explosion impact.
[0047] In one specific embodiment of the present application, the flexural strength of the foamed concrete reinforcement layer 3 is 1.2-2 MPa. Oil and gas pipelines are subject to a certain degree of vibration and deformation under long-term temperature and pressure. When wrapping and filling the pipeline, the foamed concrete reinforcement layer 3 is designed with a relatively thin top and side filling thickness to accommodate tunnel clearance and maintenance passage 31. When the pipeline vibrates or deforms, static or dynamic relative displacement occurs between the pipeline and the foamed concrete. Foamed concrete is inherently brittle and is highly susceptible to cracking under deformation. To reduce the risk of cracking in the foamed concrete reinforcement layer 3, fiber reinforcement is used to increase its strength, especially its tensile strength, and enhance the toughness of the foamed concrete reinforcement layer 3 structure. To this end, requirements for its flexural strength are established.
[0048] In this application, according to the filling technology requirements for different spatial distribution fillings in the tunnel, a foam concrete filling layer 1, a foam concrete structural layer 2 and a foam concrete reinforcement layer 3 with different strengths are gradiently set up. On the one hand, the construction efficiency is improved, and on the other hand, the anti-floating performance requirements of the foam concrete filling structure in the tunnel are met, avoiding the risk of floating of the foam concrete filling structure caused by leakage in the cross-river tunnel during operation, and reducing the risk of leakage due to pipe bending.
[0049] In a specific embodiment of the present application, a pipeline base is provided below the pipeline ( Figure 1 (not shown). In the present application, before filling, it is necessary to install the pipe on the pipe base to place the pipe and improve stability. The pipe base will also be filled and protected, and will not affect the filling strength adjustment of the present application. Its structure can refer to the existing technology and will not be repeated here.
[0050] In a specific embodiment of the present application, the anti-floating stability coefficient of the tunnel is K satisfy:
[0051] ;
[0052] in, M 1——the deadweight of the foam concrete filling layer 1;
[0053] M 2——the deadweight of the foam concrete structure layer 2;
[0054] M 3——the deadweight of the foam concrete reinforcement layer 3;
[0055] M p - the deadweight of the pipeline;
[0056] M q - the deadweight of the pipe base;
[0057] ρ - density of water;
[0058] g - acceleration due to gravity;
[0059] V — volume of the tunnel;
[0060] K ——The anti-floating stability coefficient of the tunnel.
[0061] Long-distance oil and gas pipeline tunnels generally need to be buried deep underground and may also need to pass under rivers. The tunnels may encounter groundwater or leakage nearby. This application controls the anti-floating stability coefficient of the tunnel, which is conducive to maintaining the stability of long-distance tunnels and effectively avoiding the risk of bending caused by floating.
[0062] This application provides a method for filling and protecting pipelines with highly fluid foam concrete, which facilitates construction. Based on the filling technology requirements for different spatial distributions within the tunnel, a foam concrete filling layer 1, a foam concrete structural layer 2, and a foam concrete reinforcement layer 3 with different strengths are gradiently arranged. This improves construction efficiency, reduces the risk of cracking caused by pipeline vibration, and helps maintain tunnel stability and extend its service life. Furthermore, it meets the anti-floating performance requirements of the foam concrete filling structure within the tunnel, avoids the risk of the foam concrete filling structure floating due to leakage in the cross-river tunnel during operation, and reduces the risk of leakage due to pipeline bending. This is of great significance to my country's long-distance, large-diameter oil and gas pipeline transportation.
[0063] It should be understood that the application of this application is not limited to the above examples. For ordinary technicians in this field, they can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of this application.
Claims
1. A foam concrete filling structure for a large diameter oil and gas pipeline tunnel, comprising a tunnel, characterized in that: From bottom to top in the tunnel, it includes a foam concrete filling layer (1), a foam concrete structural layer (2) and a foam concrete strengthening layer (3); A channel (31) is provided in the central area of the foamed concrete strengthening layer (3) to separate the foamed concrete strengthening layer (3) and expose the foamed concrete structural layer (2); A pipe is provided in the foam concrete filling layer (1), and a pipe is provided on each of the two partitioned sides of the foam concrete strengthening layer (3).
2. The foam concrete filling structure for large diameter oil and gas pipeline tunnels according to claim 1, characterized in that: The distance between the top surface of the foam concrete reinforcement layer (3) and the top of the tunnel is not less than 2m, and the separation distance of the channel (31) is not less than 1.2 times the diameter of the pipe and not less than 0.5m.
3. The foam concrete filling structure for large diameter oil and gas pipeline tunnel according to claim 2, characterized in that: The ratio of the diameter of the pipeline to the diameter of the tunnel is 0.3-0.42:1, the ratio of the thickness of the foamed concrete filling layer (1) to the diameter of the pipeline is 1.15-1.4:1, and the ratio of the thickness of the foamed concrete strengthening layer (3) to the diameter of the pipeline is 1.05-1.10:
1.
4. The foam concrete filling structure for large diameter oil and gas pipeline tunnel according to claim 3, characterized in that: The thickness of the foamed concrete structural layer (2) is 0.5-0.8 m.
5. The foam concrete filling structure for large diameter oil and gas pipeline tunnel according to claim 1, characterized in that: The compressive strength of the foamed concrete filling layer (1) is 1.5-2 MPa, the compressive strength of the foamed concrete structural layer (2) is 2-3 MPa, and the compressive strength of the foamed concrete strengthening layer (3) is 3-5 MPa.
6. The foam concrete filling structure for large diameter oil and gas pipeline tunnels according to claim 1, characterized in that: The flexural strength of the foam concrete reinforcement layer (3) is 1.2-2 MPa.
7. The foam concrete filling structure for large diameter oil and gas pipeline tunnel according to claim 1, characterized in that: A pipeline base is arranged below the pipeline.
8. The foam concrete filling structure for large diameter oil and gas pipeline tunnels according to claim 7, characterized in that: Tunnel anti-floating stability factor K satisfy: ； M 1 is the deadweight of the foamed concrete filling layer (1), M 2 is the deadweight of the foamed concrete structure layer (2), M 3 is the deadweight of the foamed concrete reinforcement layer (3), M p is the dead weight of the pipeline, M q is the deadweight of the pipeline base, V is the volume of the tunnel, ρ is the density of water, g is the acceleration due to gravity.