Isolation method giving consideration to tunnel anti-floating and pipeline in-situ protection

Abstract

The invention relates to the technical field of civil engineering, in particular to an isolation method giving consideration to tunnel anti-floating and pipeline in-situ protection, pile foundations are implemented on two sides of a tunnel or a pipeline, and the burial depth of the pile foundations is lower than that of the tunnel; a working well is constructed at the position of the pile foundation, and the well bottom elevation of the working well is located between the pipeline and the tunnel; jacking a steel pipe cross beam in the working well, wherein the steel pipe cross beam communicates with the working wells on the two sides; a concrete cross beam is constructed in the steel pipe cross beam, the concrete cross beam is arranged in the steel pipe cross beam, the two ends of the concrete cross beam are fixedly connected with the pile foundations on the two sides to form an integral structure, and the pile foundations, the steel pipe cross beam and the concrete cross beam form a portal frame structure; and after the portal frame structure is completed, the structure to be built is constructed. The structure has the advantages that the structure has a good upper and lower part isolation effect, the influence on the upper part is small during lower space construction, and when a lower tunnel exists, safe construction can be performed on the upper part without causing the problems of upheaval or insufficient floating resistance and the like of the lower existing tunnel.

Description

Technical Field

[0001] The present invention relates to the technical field of civil engineering, and particularly relates to an isolation method that takes into account tunnel anti-floating and in-situ protection of pipelines, which can be used for settlement adjustment of existing pipelines or building foundations, can also be used to protect existing pipelines or building foundations from settlement, and can also be used as an isolation structure between existing pipelines or building foundations and the upcoming project below to protect the safety of the existing project and the upcoming project. Background Art

[0002] When there is insufficient anti-floating in the design and construction of shallow-buried urban tunnels, various methods such as applying overburden pressure, adding counterweights in the tunnel, and anti-floating pressure plates can be used, but there are some problems with all of them. For example, applying overburden pressure will cause ground settlement; when adding counterweights in a limited tunnel space, it often has little effect; the construction of anti-floating pressure plates requires breaking and restoring the road surface, causing traffic diversion or pipeline relocation. When many adverse factors are concentrated, there are many pipelines, or there are major pipelines that are difficult to relocate, the above solutions all seem inadequate; conversely, when there is an existing shallow-buried tunnel below and upper excavation operations are required, the tunnel needs to be protected first before starting the upper operations. Based on this, there is an urgent need to study an isolation method and construction method that take into account tunnel anti-floating and in-situ protection of pipelines. Summary of the Invention

[0003] The purpose of the present invention is to provide an isolation method that takes into account tunnel anti-floating and in-situ protection of pipelines according to the deficiencies of the above-mentioned existing technologies. The main load-bearing members adopt trenchless technology to implement in-situ protection of underground shallow pipelines; at the same time, this structure can provide a protection effect similar to that of a portal frame for the lower tunnel to ensure the safety of the lower space construction; at the same time, due to the strong stiffness of this structural system, it plays an isolation role for the upper and lower buildings and structures and can also be used for the protection of excavation operations above the existing tunnel.

[0004] The object of the present invention is achieved by the following technical solutions: An isolation method that takes into account tunnel anti-floating and in-situ protection of pipelines, characterized in that: the isolation method includes the following steps: Implement pile foundations on both sides of the tunnel or pipeline, and the buried depth of the pile foundations is lower than that of the tunnel, where one of the tunnel and the pipeline is an existing structure and the other is an upcoming structure; Construct a working well at the position of the pile foundation, and the bottom elevation of the working well is located between the pipeline and the tunnel; Jack in a steel pipe cross beam in the working well, and the steel pipe cross beam connects the two working wells on both sides; Construct a concrete cross beam inside the steel pipe cross beam, the concrete cross beam is arranged inside the steel pipe cross beam, and both ends of the concrete cross beam are fixedly connected to the pile foundations on both sides to form an integral structure, and the pile foundations, steel pipe cross beam and concrete cross beam form a portal frame structure; After the portal frame structure is completed, the structure to be built is constructed.

[0005] The steel bars of the concrete cross beam and the steel bars of the pile foundation are cross-anchored with each other and concrete is poured to complete the connection between the two.

[0006] When the quantity or spacing of the concrete cross beam and the pile foundation do not match, a longitudinal beam is arranged at the top of the pile foundation, and the steel bars of the concrete cross beam are anchored into the longitudinal beam.

[0007] The advantages of the present invention are as follows: 1) The structural stress form is simple, clear and reliable.

[0008] 2) The structure mainly adopts the non-excavation process, which can avoid road restoration and the impact on traffic.

[0009] 3) The structure has a good upper and lower isolation effect. When constructing the lower space, the impact on the upper part is small. On the contrary, when the lower tunnel already exists, construction can be carried out safely on the upper part without causing problems such as the uplift or insufficient anti-floating of the existing lower tunnel.

[0010] 4) The main supporting members are constructed by using a small pipe jacking machine, which is convenient for construction, has little impact, and has large stiffness and strong bearing capacity.

[0011] 5) It has better reliability, good innovation and application value, and is worthy of popularization. Description of the Drawings

[0012] Figure 1 is the plan layout drawing of the present invention; Figure 2 is the cross-sectional drawing of the steel pipe cross beam in the present invention; Figure 3 is the combined cross-sectional drawing of the steel pipe cross beam and the concrete cross beam in the present invention; Figure 4 is the construction flow chart of the present invention. Detailed Embodiments

[0013] The features of the present invention and other related features are further described in detail below through embodiments with reference to the drawings for the understanding of those skilled in the same industry: As Figures 1-4 shown, the reference numerals 1-8 in the figure respectively represent: pipeline 1, working shaft 2, steel pipe cross beam 3, concrete cross beam 4, pile foundation 5, tunnel 6, concrete 7, steel bar 8.

[0014] Embodiment 1: As Figures 1 to 3As shown in the figure, in this embodiment, the isolation method that takes into account both tunnel anti-floating and in-situ protection of pipelines is applied to the situation where pipeline 1 already exists and a tunnel 6 needs to be constructed below pipeline 1 (especially suitable for the condition where the buried depth of tunnel 6 is relatively shallow), and in-situ protection of pipeline 1 is required.

[0015] Specifically, when this embodiment is applied, it includes the following steps: 1) Select a reasonable location for working shaft 2 according to the positional relationship between the existing pipeline 1 and the to-be-built tunnel 6, and considering the influence of factors such as ground traffic.

[0016] 2) Implement pile foundation 5 at the corresponding position of working shaft 2.

[0017] 3) Implement working shaft 2, and the bottom elevation of this working shaft 2 is located between pipeline 1 and tunnel 6.

[0018] 4) Jack in construction steel pipe cross beam 3 in working shaft 2, and this steel pipe cross beam 3 mainly plays a role in advanced support and guiding holes for the construction of concrete cross beam 4.

[0019] 5) Fabricate the steel cage of concrete cross beam 4, use the sectional connection process to penetrate it into steel pipe cross beam 3, and at the same time, the steel bars of concrete cross beam 4 and the steel bars of pile foundation 5 are cross-anchored, and pour (press) concrete to complete the construction of concrete cross beam 4.

[0020] In this embodiment, during actual use, if the quantity or spacing of concrete cross beam 4 and pile foundation 5 do not match, longitudinal beams can be set at the top of pile foundation 5, and the steel bars of concrete cross beam 4 are anchored into this longitudinal beam to achieve effective connection.

[0021] 6) Backfill working shaft 2.

[0022] After the above steps are completed, the upper pipeline 1 and the stratum are both under the in-situ protection of the portal frame structure composed of steel pipe cross beam 3, concrete cross beam 4, and pile foundation 5, and the construction operation of the lower tunnel can be carried out safely. At the same time, for shallow overburden sections, this structure can also be used as anti-floating ballast for the tunnel, achieving multiple benefits with one action.

[0023] Embodiment 2: The difference between this embodiment and Embodiment 1 is that this embodiment is for the situation where the lower tunnel 6 already exists (especially suitable for the condition where the buried depth of tunnel 6 is relatively shallow), and it is necessary to excavate the soil to implement the upper pipeline 1, that is, the situation opposite to that of Embodiment 1.

[0024] 1) Select a reasonable location for working shaft 2 according to the positional relationship between the existing tunnel 6 and the to-be-built pipeline 1, and considering the influence of factors such as ground traffic.

[0025] 2) Implement pile foundation 5.

[0026] 3) Implement working shaft 2.

[0027] 4) Jack and construct the steel pipe cross beam 3 in the working shaft 2.

[0028] 5) Fabricate the steel reinforcement cage of the concrete cross beam 4, and penetrate it into the steel pipe cross beam 3 by using the sectional connection process. At the same time, the steel bars of the concrete cross beam 4 and the steel bars of the pile foundation 5 are cross-anchored with each other, and then pour (press) the concrete to complete the construction of the concrete cross beam 4.

[0029] 6) Backfill the working shaft 2.

[0030] After the above steps are completed, the existing tunnel 6 below is already under the safety protection of the portal frame structure. When the upper soil is excavated and unloaded, there will be no problems such as insufficient anti-floating or ground heave causing functional disorders. At the same time, when additional soil cover or load needs to be added on the ground, the lower tunnel can also be safely protected by using this embodiment.

[0031] Although the above embodiments have described in detail the concept and embodiments of the present invention with reference to the accompanying drawings, those of ordinary skill in the art can recognize that various improvements and modifications can still be made to the present invention without departing from the scope defined by the claims. Therefore, they are not elaborated here one by one.

Claims

1. An isolation method that takes into account both tunnel anti-floating and in-situ protection of pipelines, characterized in that: The isolation method includes the following steps: Implement pile foundations on both sides of the tunnel or pipeline, with the buried depth of the pile foundations lower than that of the tunnel, where one of the tunnel and the pipeline is an existing structure and the other is a to-be-built structure; Construct a working shaft at the position of the pile foundation, with the bottom elevation of the working shaft located between the pipeline and the tunnel; Jack in a steel pipe cross beam in the working shaft, and the steel pipe cross beam connects the working shafts on both sides; Construct a concrete cross beam inside the steel pipe cross beam. The concrete cross beam is arranged inside the steel pipe cross beam, and both ends of the concrete cross beam are respectively connected and fixed to the pile foundations on both sides to form an integral structure. The pile foundations, steel pipe cross beam and concrete cross beam form a portal frame structure; After the portal frame structure is completed, construct the to-be-built structure.

2. The isolation method that takes into account both tunnel anti-floating and in-situ protection of pipelines according to claim 1, characterized in that: Cross-anchor the steel bars of the concrete cross beam and the steel bars of the pile foundation and pour concrete to complete the connection between the two.

3. The isolation method that takes into account both tunnel anti-floating and in-situ protection of pipelines according to claim 1, characterized in that: When the quantity or spacing of the concrete cross beam and the pile foundation do not match, a longitudinal beam is arranged at the top of the pile foundation, and the steel bars of the concrete cross beam are anchored into the longitudinal beam.

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