A shallow-buried under-pipe trenchless structure

Abstract

The utility model belongs to underground pipeline technical field, concretely relates to a shallow burying underpass pipeline trenchless structure. Including pipe shed, pipe shed support and support base, pipe shed is constituted by steel flower pipe, is arranged in rectangular section, steel flower pipe distributes in the top and both sides of rectangular section, pipe shed support adopts I -beam, is arranged on support base, and constitutes the support system with pipe shed together, underpass pipeline is located in the inside of pipe shed, and after construction is completed, passes through the bottom of the structure that is worn, and the clearance between pipe shed and underpass pipeline is filled with medium coarse sand. The steel flower pipe of pipe shed is consolidated with surrounding soil through cement slurry or double slurry grouting, and forms the reinforcement area. The support base is arranged at the bottom of the underground excavation construction area, and the foundation reinforcement treatment is carried out when encountering poor foundation. The structure does not affect the normal operation of the crossed structure during construction, and has little influence on the above structures such as the crossed existing pipeline, aqueduct and irrigation canal.

Description

Technical Field

[0001] This utility model belongs to the field of underground pipeline technology, specifically relating to a trenchless structure for shallow buried underground pipelines. Background Technology

[0002] In existing pipeline underpass projects, trenchless construction techniques are often used to avoid damage to existing structures when crossing existing pipelines, aqueducts, or irrigation canals. However, traditional structural designs have significant shortcomings: if the diameter of the underpass pipeline is large, the burial depth of the pipeline often needs to be significantly increased to meet the minimum clearance requirements between the pipeline and the structure being crossed. This adjustment in burial depth can lead to a series of structural problems: increased burial depth results in a significant increase in earth pressure, making it difficult for existing support systems (such as pipe jacking or directional drilling systems) to balance the load under shallow burial conditions, which can easily cause deformation or instability of the support structure and threaten the safety of the structure being crossed; existing support systems are mostly designed for deep burial conditions, and it is difficult to effectively control ground settlement and disturbance of the surrounding soil in shallow burial scenarios, especially for large-diameter pipelines, where insufficient structural redundancy can easily cause surface subsidence or displacement of existing pipelines during construction.

[0003] Therefore, there is an urgent need for a new structural system that can meet the clearance requirements for large-diameter pipelines under shallow burial conditions, while reducing the dependence on the support system and foundation. Utility Model Content

[0004] To address the aforementioned technical issues, this utility model proposes a trenchless structure for shallow-buried underground pipelines. This structure does not affect the normal operation of the structures being crossed during construction, has minimal impact on existing pipelines and structures above them such as aqueducts and irrigation canals, requires less construction workspace, is easily visible and monitorable, and has a short construction cycle.

[0005] To achieve the above objectives, the present invention specifically adopts the following technical solution:

[0006] A trenchless structure for shallow-buried underground pipelines includes a pipe roof, pipe roof supports, and support foundations. The pipe roof is constructed of steel perforated pipes arranged in a rectangular cross-section, with the steel perforated pipes distributed at the top and sides of the rectangular cross-section. The pipe roof supports are made of I-beams, arranged on the support foundation, and together with the pipe roof, form a support system. The underground pipeline is located inside the pipe roof and passes through the bottom of the structure to be penetrated after construction. Medium-coarse sand is used to fill the gap between the pipe roof and the underground pipeline.

[0007] Furthermore, the steel pipes of the pipe shed are solidified with the surrounding soil by grouting with cement grout or double grout to form a reinforced area.

[0008] Furthermore, the supporting foundation is set at the bottom of the tunnel construction area, and foundation reinforcement treatment is carried out when encountering poor foundation.

[0009] Correspondingly, this solution also provides a trenchless construction method for shallow-buried underground pipelines, including the following steps:

[0010] a. Conduct underground excavation in the area to be traversed, and install pipe roofs and pipe roof supports while excavating and removing slag, ensuring that the steel pipes of the pipe roof pass through the bottom of the structure to be traversed;

[0011] b. Inject cement grout or double grout into the steel pipe using a backward segmented grouting process at a pressure of 0.5–0.8 MPa to reinforce the bottom and surrounding soil of the penetrated structure;

[0012] c. The underpass pipeline enters the pipe shed and extends to the other side of the bottom of the structure being penetrated;

[0013] d. The gap between the pipe roof and the underground pipeline is backfilled and compacted with medium-coarse sand; areas that cannot be compacted are filled with grout.

[0014] e. Monitor the stability of the support system throughout the construction process to ensure the normal operation of the structure being penetrated.

[0015] Furthermore, during the tunnel excavation, the pipe roof support is installed synchronously with the tunneling progress.

[0016] Furthermore, the burial depth of the underground pipeline is less than the net distance requirement at the bottom of the structure being penetrated.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects:

[0018] By employing a support system combining rectangular cross-section steel pipe roofs and I-beam supports, the underground pipeline can safely pass through the structure it is piercing at a relatively shallow burial depth. This design avoids the problem of significantly increasing the burial depth due to the large pipe diameter required in traditional pipe jacking or directional drilling construction, reducing construction difficulty and cost, while meeting the clearance requirements between the pipeline and the structure being pierced, significantly improving the feasibility of shallow trenchless construction.

[0019] The steel pipe shed reinforces the surrounding soil through grouting, forming a stable pre-support structure that effectively reduces the risk of soil loosening during excavation. Combined with I-beam supports that provide simultaneous excavation and support, ground deformation is controlled in real time. This technology protects the structural safety of the structure being penetrated while avoiding interference with its normal operation during construction, making it particularly suitable for pipeline crossing projects in complex environments during urban renewal.

[0020] The underground excavation method for rectangular pipe roofs, combined with visual monitoring technology, reduces the required working area, the amount of earthwork excavation and backfilling, and significantly shortens the construction period. At the same time, the construction process does not require interruption of the operation of the structure being penetrated, minimizing the impact on the surrounding environment and social activities, thus aligning with the concept of green construction. Attached Figure Description

[0021] Figure 1 This is an elevation view of a specific embodiment of the present utility model;

[0022] Figure 2 This is a top view of a specific embodiment of the present invention;

[0023] Figure 3 This is a cross-sectional view AA of a specific embodiment of the present invention. Attached image description:

[0025] 1. Pipe shed; 2. Pipe shed support; 3. Support foundation; 4. Structure being penetrated; 5. Bottom of structure being penetrated; 6. Underpass pipeline; 7. Medium-coarse sand. Detailed Implementation

[0026] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0027] like Figures 1-3 The diagram illustrates a trenchless structure for a shallow-buried underground pipeline, consisting of a steel pipe canopy 1, a canopy support 2, and a support foundation 3. The top steel pipe passes through the bottom 5 of the structure being penetrated 4, forming the canopy together with the side steel pipes. During construction, the pipe canopy is used for support while excavating and removing slag, in conjunction with other support methods such as shotcreting. After the underground pipeline 6 passes through the structure being penetrated, the gaps within the pipe canopy are backfilled and compacted with medium-coarse sand 7. Areas that cannot be compacted are treated with grouting. The pipe canopy generally adopts a rectangular cross-section, with the steel pipes arranged at the top and sides of the rectangular cross-section. Cement grout or a dual-grout mixture is used as the grouting material.

[0028] like Figure 1 , Figure 3 As shown, when encountering a large-diameter underground pipeline 6, and the burial depth is excessive to meet the net distance requirement between it and the bottom 5 of the structure 4 being penetrated, this utility model works well. A rectangular pipe shed is constructed using steel perforated pipes 1, and excavation is carried out underground. The pipe shed supports 2 while removing slag. The pipe shed supports are set on the support foundation 3. If the foundation is weak, it must be treated. After the underground pipeline passes through, the gaps inside the pipe shed are backfilled. The steel perforated pipes are arranged along the top and sides of the pipe shed. The pipe shed supports use I-beams, with a general spacing of 1m, determined by calculation based on actual conditions. The steel perforated pipes generally use a backward-retreating segmented grouting method, using 1:1 cement grout as the grouting material, with a grouting pressure of 0.5–0.8 MPa. After the underground pipeline passes through, the gaps in the pipe shed are generally backfilled and compacted with medium-coarse sand. Where compaction is not possible, cement grout or a double-slurry grouting method is used.

[0029] Please see Figures 1-3 The specific implementation method of the trenchless construction method for shallow buried underground pipelines provided by this utility model is as follows:

[0030] Support system construction: as attached Figure 1 As shown, the initial excavation in the area to be traversed involves tunneling, with the installation of a pipe roof 1 (composed of steel perforated pipes) and I-beam pipe roof supports 2 simultaneously with the excavation and muck removal. The pipe roof 1 has a rectangular cross-section, with the steel perforated pipes positioned at the top and sides. Cement grout or a dual-slurry mixture is injected into the steel perforated pipes using a backward-retreating segmented grouting process, with the grouting pressure controlled between 0.5 and 0.8 MPa, to reinforce the bottom 5 of the structure being traversed and the surrounding soil. The pipe roof supports 2 are made of I-beams and are positioned on a support foundation 3 located at the bottom of the tunneled area. If poor ground conditions are encountered, pre-construction ground reinforcement is required.

[0031] Synchronous support and soil control: During construction, the pipe roof support 2 is installed synchronously with the excavation progress to ensure a tight connection between the support system and the excavation face. The steel pipe roof 1 forms a reinforced area through grouting, effectively inhibiting soil loosening and deformation. During the tunneling process, the stability of the support system and surface settlement are monitored in real time to ensure the normal operation of the penetrated structure 4.

[0032] Pipeline crossing and backfilling: After the support system is completed, the underpass pipeline 6 is inserted into the pipe roof 1, extending to the other side of the bottom 5 of the structure being crossed. Subsequently, the gap between the pipe roof 1 and the underpass pipeline 6 is backfilled in layers with medium-coarse sand 7 and compacted. For areas that cannot be compacted, cement grout or a double-grout solution is used for grouting to ensure the density of the gaps.

[0033] Visual monitoring: High-precision monitoring equipment is used throughout the construction process to provide real-time feedback on the deformation data of the support system and the stress state of the soil. If any abnormality is detected, construction is immediately suspended and the support parameters are adjusted. Visual monitoring technology ensures construction accuracy and the safety of the structure being penetrated.

[0034] Measures to address poor foundation conditions: When a weak soil layer exists beneath the supporting foundation 3, foundation reinforcement is necessary to improve the bearing capacity of the supporting foundation 3. Simultaneously, the steel pipe grouting process allows for adjustments to the grouting material ratio and pressure parameters based on actual geological conditions to ensure effective reinforcement.

[0035] Construction Completion and Acceptance: After construction is completed, a comprehensive inspection will be conducted on the backfill compaction, grouting effect, and stability of the support structure to ensure that design requirements are met. Upon successful acceptance, the surface will be restored to its original state to minimize the impact on the surrounding environment.

[0036] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the present utility model. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present utility model shall still fall within the protection scope of the present utility model.

Claims

1. A trenchless structure for shallow-buried underground pipelines, characterized in that, It includes a pipe shed (1), a pipe shed support (2), and a support foundation (3); the pipe shed (1) is made of steel pipes and arranged in a rectangular cross section, with the steel pipes distributed on the top and sides of the rectangular cross section; the pipe shed support (2) is made of I-beams and arranged on the support foundation (3), and together with the pipe shed (1) forms a support system; the underpass pipeline (6) is located inside the pipe shed (1) and passes through the bottom (5) of the structure to be penetrated after construction is completed; the medium-coarse sand (7) fills the gap between the pipe shed (1) and the underpass pipeline (6).

2. The trenchless structure for shallow-buried underground pipelines according to claim 1, characterized in that, The steel pipes of the pipe shed (1) are solidified with the surrounding soil by grouting with cement grout or double grout to form a reinforced area.

3. The trenchless structure for shallow-buried underground pipelines according to claim 1, characterized in that, The supporting foundation (3) is set at the bottom of the underground excavation area and is reinforced when encountering poor foundation.

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