Existing subway tunnel reinforcing structure adopting concrete filled steel tube mixing composite piles

Abstract

The utility model relates to the technical field of existing building foundation reinforcement treatment, in particular to an existing subway tunnel reinforcement structure adopting a concrete-filled steel tube mixing composite pile, which comprises a mixing pile and a concrete-filled steel tube core pile from outside to inside, the concrete-filled steel tube core pile is composed of a steel tube and concrete poured into the steel tube, the pile top of the concrete-filled steel tube mixing composite pile is located outside the duct piece, a reinforcement cage is arranged in the pile head of the concrete-filled steel tube mixing composite pile in a penetrating mode, and a longitudinal beam is arranged in the subway tunnel. And the longitudinal beams and the reinforcement cage are connected and fixed to form an integral structure. The utility model has the advantages of large pile forming, reasonable structure stress, high bearing capacity, short construction equipment, slight disturbance, no pollution, low vibration and low noise.

Description

Technical Field

[0001] The utility model relates to the technical field of existing building foundation reinforcement treatment, in particular to an existing subway tunnel reinforcement structure using steel tube concrete mixing composite piles. Background Art

[0002] With the increase of subway lines in operation and the extension of operation time in my country, more and more subways have suffered from deformation diseases, especially in soft soil areas. More and more subway tunnels have suffered from deformation diseases. The deformation mainly includes settlement, lateral deformation, convergence deformation, etc. As the deformation progresses, tunnels have suffered from water leakage, segment misalignment and other diseases, affecting the driving safety of the line.

[0003] At present, there are two main reinforcement measures for subway deformation diseases: inside the tunnel and outside the tunnel:

[0004] 1. Tunnel reinforcement measures:

[0005] Steel rings are installed inside the tunnel for reinforcement to increase the overall stiffness of the shield tunnel and reduce differential settlement; cracks in the segments are repaired using methods such as gluing composite cavity reinforcement, aramid cloth reinforcement, and carbon fiber cloth reinforcement.

[0006] 2. External reinforcement method:

[0007] The external reinforcement mainly adopts the grouting reinforcement method, which is to reinforce the soil around the tunnel by grouting to improve the mechanical properties of the surrounding soil and thus reduce the deformation of the tunnel.

[0008] With the current reinforcement technology, the in-tunnel reinforcement method only treats the symptoms and not the root cause, and the reinforcement effect is limited; the out-of-tunnel grouting method is greatly affected by factors such as construction technology, soil quality, and environment, and the reinforcement effect is difficult to control and the construction is difficult. Summary of the invention

[0009] The utility model aims to provide an existing subway tunnel reinforcement structure using steel tube concrete mixing composite piles in accordance with the above-mentioned deficiencies of the prior art, wherein a large-diameter composite pile larger than the bottom plate hole diameter is constructed by opening a small hole in the bottom plate or side wall of the existing subway tunnel, thereby achieving the purpose of "opening a small hole to form a large pile"; the composite pile is provided with friction force by an external large-diameter mixing pile, and the internal steel tube concrete core pile provides pile body bearing capacity; the outer wall of the mixing pile is rough, and the friction force between it and the soil is large; the steel tube concrete core pile, due to the restraining effect of the steel tube, makes the concrete in the steel tube in a three-dimensional stress state, and the pile body bearing capacity is greatly improved compared with general concrete or pure steel tube piles, so that the composite pile has stronger compression and tension resistance. After the composite pile is reinforced, the subway tunnel is fixed in the soil to reduce its deformation.

[0010] The purpose of this utility model is achieved by the following technical solutions:

[0011] A reinforcement structure for an existing subway tunnel using a steel tube concrete mixing composite pile, which is arranged on the periphery of a tube segment of the subway tunnel, is characterized in that: the steel tube concrete mixing composite pile comprises a mixing pile and a steel tube concrete core pile from the outside to the inside, wherein the steel tube concrete core pile is arranged inside the mixing pile, the steel tube concrete core pile is composed of a steel tube and concrete poured inside the steel tube concrete mixing composite pile, the pile top of the steel tube concrete mixing composite pile is located outside the tube segment, a steel cage is inserted into the pile head of the steel tube concrete mixing composite pile, a longitudinal beam is arranged inside the subway tunnel, and the longitudinal beam is connected and fixed to the steel cage to form an integral structure.

[0012] The longitudinal beam and the subway tunnel are connected by embedded reinforcement.

[0013] The steel pipe adopts an assembled structure, which is composed of a plurality of steel pipe segments spliced ​​together.

[0014] The opening of the subway tunnel is poured with expansive concrete.

[0015] A plurality of the steel tube concrete mixing composite piles are arranged outside the pipe segments of the subway tunnel, and some of the steel tube concrete mixing composite piles are arranged in an inclined manner.

[0016] The advantages of the utility model are:

[0017] 1) Large pile, reasonable structural stress, high bearing capacity: a small hole is opened through the wall of the existing subway tunnel, and after the folding mixing head and the steel pipe pass through, the folding mixing head is opened to form a large-diameter composite pile larger than the bottom plate aperture; the composite pile is provided with friction by the external large-diameter mixing pile, and the internal steel tube concrete core pile provides the pile body bearing capacity, so as to achieve the purpose of "opening a small hole to form a large pile"; the outer wall of the mixing pile is rough, and the friction between it and the soil is large. The steel tube concrete core pile, due to the constraint of the steel pipe, makes the concrete in the steel pipe in a three-dimensional stress state, and its pile body bearing capacity is greatly improved compared with general concrete or pure steel pipe piles, so that the composite pile has strong compression and tensile resistance. After reinforcement with this type of pile, it is like driving expansion screws into the soil around the tunnel, fixing the subway tunnel in the soil and reducing its deformation; compared with the common methods of repairing in the hole and grouting outside the hole, the deformation control effect is greatly improved, and the construction quality is easy to guarantee.

[0018] 2) The construction equipment is short: Steel pipes are connected section by section to form piles. Each section of the steel pipe can be adjusted according to the clear height of the existing subway tunnel. The equipment is short and has strong applicability.

[0019] 3) Micro-disturbance: The mixing pile and steel pipe synchronous pile-making process is adopted. After the pile head mixes the lower soil into a fluidized cement soil, the steel pipe follows up synchronously. There is no soil squeezing effect and the disturbance to the surrounding environment is very small.

[0020] 4) No pollution, low vibration and noise: No waste such as mud will be generated during the construction process, and the vibration and noise during the construction process are also very small, which is environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The construction steps of the utility model are as follows: Figure Ⅰ ;

[0022] Figure 2 The construction steps of the utility model are as follows: Figure II ;

[0023] Figure 3 The construction steps of the utility model are as follows: Figure III ;

[0024] Figure 4 The construction steps of the utility model are as follows: Figure IV ;

[0025] Figure 5 It is a structural schematic diagram of the utility model after construction is completed. DETAILED DESCRIPTION

[0026] The following is a further detailed description of the features of the present invention and other related features through embodiments in conjunction with the accompanying drawings to facilitate understanding by technicians in the same industry:

[0027] like Figure 1-5 As shown, the marks 1-14 in the figure respectively represent: cement slurry pump 1, grouting hose 2, folding mixing head 3, steel pipe 4, grouting steel pipe 5, rotary power head 6, frame 7, tunnel wall 8, concrete pouring equipment 9, steel pipe joint 10, concrete 11, steel cage 12, longitudinal beam 13, steel tube concrete mixing composite pile 14.

[0028] Example: Combination Figures 1 to 5 As shown, the construction process of the existing subway tunnel reinforcement structure using steel tube concrete mixing composite piles in this embodiment is as follows:

[0029] 1) Drill holes on the tunnel wall 8 of an existing subway tunnel. Depending on the deformation of the subway tunnel, holes may be drilled at the tunnel floor and side wall positions.

[0030] 2) The steel pipe 4 and the folding mixing head 3 pass through the bottom plate opening 8 to the foundation, and the rotary power head 6 holds the steel pipe 4 and rotates, driving the folding mixing head 3 at the bottom to rotate. Under the resistance of the soil, the folding mixing head 3 unfolds and cuts the soil. At the same time, the cement slurry pump 1 sprays cement slurry to the folding mixing head 3 through the grouting hose 2 and the grouting steel pipe 5. The pile head soil is fully mixed with the cement slurry under the stirring of the folding mixing head 3 to form a large cement-soil pile. At the same time, the frame 7 drives the steel pipe 4 and the folding mixing head 3 to sink while stirring in the soil. If re-mixing is required, the frame 7 can also drive the steel pipe 4 and the folding mixing head 3 to stir reciprocally up and down to complete the re-mixing.

[0031] 3) After the construction of one section of the mixing pile is completed, the next section of the steel pipe 4 and the grouting steel pipe 5 in the steel pipe 4 are connected by threading or welding, and steel pipe joints 10 are formed between each steel pipe segment; the second step is repeated to complete the mixing pile construction section by section to the designed pile length. After the mixing pile construction is completed, concrete 11 is poured into the hollow steel pipe 4 through the concrete pouring equipment 9 placed in the subway tunnel to form a steel tube concrete mixing composite pile 14.

[0032] 4) Before pouring the upper concrete, a connecting steel cage 12 is arranged in the steel pipe 4 to connect the longitudinal beam 13 arranged on the bottom plate of the existing building. The longitudinal beam 13 is connected to the bottom plate of the subway tunnel by planting reinforcement. Expansive concrete is poured into the opening of the subway tunnel to make the opening concrete and the bottom plate tightly connected, so that the subway tunnel and the steel tube concrete mixing composite pile 14 form an integral force-bearing structure.

[0033] 5) According to the deformation and stress conditions of the tunnel, multiple piles can be used for reinforcement to fix the deformed tunnel in the surrounding soil and reduce the deformation of the tunnel.

[0034] Although the above embodiments have described the concepts and embodiments of the purpose of the utility model in detail with reference to the accompanying drawings, ordinary technicians in this field can recognize that various improvements and modifications can still be made to the utility model without departing from the scope of the claims, so they are not described one by one here.

Claims

1. An existing subway tunnel reinforcement structure using steel tube concrete mixing composite piles, arranged on the periphery of the subway tunnel segment, characterized in that: The steel tube concrete mixing composite pile comprises a mixing pile and a steel tube concrete core pile from the outside to the inside, wherein the steel tube concrete core pile is arranged inside the mixing pile, the steel tube concrete core pile is composed of a steel tube and concrete poured inside the steel tube concrete mixing composite pile, the pile top of the steel tube concrete mixing composite pile is located outside the pipe segment, a steel cage is inserted into the pile head of the steel tube concrete mixing composite pile, a longitudinal beam is arranged inside the subway tunnel, and the longitudinal beam is connected and fixed to the steel cage to form an integral structure.

2. The existing subway tunnel reinforcement structure using steel tube concrete mixing composite piles according to claim 1 is characterized in that: The longitudinal beam and the subway tunnel are connected by embedded reinforcement.

3. The existing subway tunnel reinforcement structure using steel tube concrete mixing composite piles according to claim 1 is characterized in that: The steel pipe adopts an assembled structure, which is composed of a plurality of steel pipe segments spliced ​​together.

4. The existing subway tunnel reinforcement structure using steel tube concrete mixing composite piles according to claim 1 is characterized in that: The opening of the subway tunnel is poured with expansive concrete.

5. The existing subway tunnel reinforcement structure using steel tube concrete mixing composite piles according to claim 1 is characterized in that: A plurality of the steel tube concrete mixing composite piles are arranged outside the pipe segments of the subway tunnel, and some of the steel tube concrete mixing composite piles are arranged in an inclined manner.

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