Mechanical method connecting channel door ring beam structure

Abstract

A mechanical method connecting channel door ring beam structure, the connecting channel is communicated to the opening position of the main line tunnel, the opening position is embedded with a door steel ring, the pipe piece of the connecting channel on the opening position is a steel pipe piece, the steel pipe piece is cut to a length that does not invade the architectural limit of the main line tunnel; a sealing steel plate is arranged on the gap between the steel pipe piece and the door steel ring, and the gap between the steel pipe piece and the pipe piece of the main line tunnel is formed into a consolidated body by grouting; the steel pipe piece and the door steel ring have an overlapping section, the door ring beam reinforcement is bound on the overlapping section, and the door ring beam reinforcement is welded with the door steel ring and the steel pipe piece respectively, a door ring beam is formed by pouring through door ring beam reinforcement formwork, and the inner arc surface of the door ring beam is flush with the inner wall of the pipe piece of the main line tunnel. The structure can make the door ring beam flush with the inner wall of the pipe piece of the main line tunnel, and does not invade the architectural limit of the main line tunnel, thereby not affecting the cable laying of the main line tunnel.

Description

Technical Field

[0001] This utility model relates to the field of tunnel construction technology, and in particular to a mechanical method for constructing a portal ring beam structure for a connecting passage. Background Technology

[0002] In tunnel engineering, especially in the construction of urban subways and underwater tunnels, transverse connecting passages are typically installed between two parallel main tunnels to meet the needs of drainage, evacuation, pipeline laying, and operation and maintenance. As the "lifeline" connecting the two main tunnels, the safety and stability of the connecting passage structure are of paramount importance.

[0003] Currently, mechanical methods, such as pipe jacking or tunnel boring machines (TBMs), are commonly used for the construction of connecting tunnels. In these methods, the casing diameter of the pipe jacking or TBM used for excavation is usually larger than the outer diameter of the connecting tunnel segments subsequently assembled. This results in a ring-shaped construction gap between the main tunnel segments and the connecting tunnel segments when the mechanical equipment starts or receives at the pre-reserved openings in the main tunnel segments.

[0004] To seal the gap in the structure, previous techniques involved directly constructing the portal ring beam structure on top of the entrance and exit tunnel segments. This portal ring beam structure was connected to the connecting tunnel segments via rebar installation. The resulting portal ring beam structure protruded beyond the surface of the main tunnel segments, causing the arch waist to encroach into the main tunnel area. This compressed the width of the evacuation platform at the arch waist, affecting cable laying in the main tunnel. Utility Model Content

[0005] To solve the above-mentioned technical problems, this utility model provides a mechanical method for connecting tunnel portal ring beam structure. This structure enables the portal ring beam to be flush with the inner wall of the main tunnel segment without encroaching on the building clearance of the main tunnel, thereby not affecting the cable laying of the main tunnel.

[0006] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0007] A mechanical method for constructing a portal ring beam structure for a connecting passage is provided, comprising a main tunnel and a connecting passage. The main tunnel segments have pre-reserved openings, and portal steel rings are pre-embedded in these openings. The connecting passage connects to the openings. The key feature is that the segments of the connecting passage at the openings are made of steel pipes, cut to a length that does not intrude into the building clearance of the main tunnel. A sealing steel plate is installed in the gap between the steel pipe segments and the portal steel ring, and the gap between the steel pipe segments and the main tunnel segments is grouted to form a solidified body. There is an overlap section between the steel pipe segments and the portal steel ring; portal ring beam reinforcement is tied to the overlap section, and the portal ring beam reinforcement is welded to both the portal steel ring and the steel pipe segments. A portal ring beam is formed by casting with formwork supporting the portal ring beam reinforcement. The inner arc surface of the portal ring beam is flush with the inner wall of the main tunnel segments and does not intrude into the building clearance of the main tunnel.

[0008] As a further improvement to the structure, the segments at the opening of the connecting passage are entrance ring segments and exit ring segments, both of which are made of Q355B grade steel segments; the solidified body is formed by single-liquid cement grout; and the width of the portal ring beam is not less than 500mm.

[0009] As a further improvement to the structure, the steel pipe segment has ribs and a back plate, the cut parts of the steel pipe segment are the ribs and the back plate, the uncut parts of the steel pipe segment have cavities, and the cavities are filled with micro-expansion cement; the overlap length between the steel pipe segment and the portal steel ring is not less than 100mm.

[0010] As a further improvement to the structure, the sealing steel plate includes an annular steel plate and reinforcing angle steel. The annular steel plate is welded between the steel pipe segment and the portal steel ring, and the reinforcing angle steel is welded to the annular steel plate and the portal steel ring. The thickness of the annular steel plate and the reinforcing angle steel is at least 10 mm. A grouting pipe is pre-embedded in the annular steel plate. Seamless steel pipes are pre-embedded at equal intervals around the circumference at 15° angles.

[0011] As a further improvement to the structure, the welding height of the portal ring beam reinforcement is not less than 8mm; the portal ring beam reinforcement is also equipped with embedded steel pipes and embedded parts for pipeline wiring in the tunnel; the portal ring beam reinforcement is composed of HRB400 main bars with diameters of 22mm, 20mm and 16mm and HPB300 stirrups with a diameter of 12mm.

[0012] The beneficial effects of this utility model are as follows: This utility model uses steel pipe segments to replace traditional reinforced concrete pipe segments, and cuts the steel pipe segments to ultimately form an "internal lining" portal ring beam. This portal ring beam is flush with the inner wall of the main tunnel pipe segments and does not encroach on the main tunnel's structural clearance. This fundamentally solves the problem of traditional outward-protruding ring beams encroaching on the main tunnel's structural clearance, ensuring the width of the evacuation platform and the space for cable and pipeline laying within the tunnel. Simultaneously, the permanent sealing structure formed by the sealing steel plate and the grouting provides a safe, reliable, and durable seal for the gaps behind the pipe segment walls, preventing water leakage. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the main tunnel and connecting passage described in this utility model;

[0014] Figure 2 This is a schematic diagram of the portal ring beam structure described in this utility model;

[0015] Marking descriptions: Main tunnel 1, connecting passage 2, portal ring beam 3, portal steel ring 4, steel pipe segment 5, cavity 51, sealing steel plate 6, ring steel plate 61, reinforcing angle steel 62, grouting pipe 7, solidified body 8, portal ring beam steel reinforcement skeleton 9. Detailed Implementation

[0016] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0017] This embodiment takes the connecting passage 2 constructed using the pipe jacking method in a subway tunnel section as an example to describe the structure of this utility model in detail.

[0018] like Figure 1 , 2 As shown, a mechanical method for constructing a portal ring beam structure is installed at the connection between the main tunnel 1 and the connecting passage 2. This structure aims to ensure that the portal ring beam 3 does not encroach on the usable space of the main tunnel.

[0019] The structure includes a main tunnel 1 and a connecting passage 2. Circular openings are pre-installed on the segments of the main tunnel 1, and portal steel rings 4 are pre-embedded in these openings. The connecting passage 2 connects to these openings. The segments of the connecting passage 2 at these openings, namely the entrance ring segments and the exit ring segments, are made of steel segments 5. In this embodiment, the steel segments 5 are preferably Q355B steel segments 5 to provide sufficient structural strength.

[0020] The steel pipe segment 5 is circumferentially cut at the rib and back plate sections that intrude into the main tunnel 1, so that the steel pipe segment 5 is cut to a length that does not intrude into the construction clearance of the main tunnel 1. The uncut sections of the steel pipe segment 5 have cavities 51, which are filled with micro-expansion cement to enhance the density and local bearing capacity of the area.

[0021] A sealing steel plate 6 is installed in the gap between the steel pipe segment 5 and the portal steel ring 4. This sealing steel plate 6 consists of a ring-shaped steel plate 61 and several reinforcing angle steels 62. The ring-shaped steel plate 61 is welded between the steel pipe segment 5 and the portal steel ring 4, while the reinforcing angle steels 62 are welded to the ring-shaped steel plate 61 and the portal steel ring 4 to enhance the rigidity and stability of the ring-shaped steel plate 61. In this embodiment, the thickness of both the ring-shaped steel plate 61 and the reinforcing angle steels 62 is not less than 10 mm.

[0022] Several grouting pipes 7 are pre-embedded at equal intervals of 15° around the annular steel plate 61. These grouting pipes 7 are... The seamless steel pipe has one end inserted into the construction gap between the steel pipe segment 5 and the main tunnel segment 1, and the other end can be used to connect to the grouting equipment. Single-liquid cement grout is injected into the construction gap through the grouting pipe 7 to form a solidified body 8. The solidified body 8 and the sealing steel plate 6 are combined to form a permanent sealing structure, effectively solving the problem of water leakage at this connection.

[0023] When cutting the steel pipe segment 5, a lap section is left between the end of the steel pipe segment 5 and the portal steel ring 4. The length of this lap section is not less than 100mm to form a space for binding the reinforcement of the portal ring beam 3. A portal ring beam reinforcement cage 9 is tied and fixed to the lap section. This portal ring beam reinforcement cage 9 is composed of HRB400 main bars with diameters of 22mm, 20mm, and 16mm, and HPB300 stirrups with a diameter of 12mm. The portal ring beam reinforcement cage 9 is welded to both the portal steel ring 4 and the steel pipe segment 5, with a welding height of not less than 8mm, thus rigidly connecting the three into a whole, playing a synergistic role, and greatly enhancing the overall structural strength and load-bearing capacity of the connected area.

[0024] During the installation of the portal ring beam steel reinforcement cage 9, pre-embedded steel pipes and other pre-embedded parts for pipeline wiring inside the tunnel are also installed on the portal ring beam steel reinforcement cage 9 to meet subsequent operational needs.

[0025] The portal ring beam 3 is formed by casting C35 concrete using steel reinforcement formwork. The width of the portal ring beam 3 is no less than 500mm, and its inner arc surface is flush with the inner wall of the main tunnel segment 1, without encroaching on the building clearance of the main tunnel 1. Through this structure, a standard "lining-type" portal ring beam 3 is formed, which completely does not encroach on the building clearance of the main tunnel 1, perfectly ensuring the space for the evacuation platform and cable conduits within the tunnel.

[0026] The construction steps for the above structure are as follows:

[0027] 1. During the prefabrication of the main tunnel segments, an opening for the tunnel jacking machine to excavate was reserved at the designed location, and a portal steel ring 4 was pre-embedded at this opening. The connecting passage 2 connects to the opening, and the connecting passage 2 has entrance and exit ring segments corresponding to the opening. These segments are all made of Q355B grade steel segments 5, and the remaining segments of the connecting passage 2 are made of reinforced concrete segments.

[0028] 2. On the 2nd to 3rd ring main tunnel segments adjacent to the opening, single-liquid cement grout or double-liquid cement grout-water glass is injected into the gap behind the wall through the grouting holes of the main tunnel segments to fill the gap between the main tunnel segments and the steel segments 5 of the connecting passage 2, preventing water and sand inrush during subsequent cutting, greatly improving the safety of subsequent cutting operations, and reducing the construction risk of water and sand inrush from the source.

[0029] 3. Using a cutting machine, the steel segments 5 at the opening of the connecting passage 2 are cut circumferentially, removing the portion of the ribs and back plates of the steel segments 5 that extend into the main tunnel 1. Simultaneously, the overlap section between the steel segments 5 and the portal steel ring 4 is retained, with an overlap length of not less than 100mm, to create space for binding the reinforcing bars of the portal ring beam 3. The uncut sections of the steel segments 5 are filled with micro-expansion cement in their cavities 51.

[0030] IV. During or after the cutting process, the gaps are sealed, and grouting pipes 7 are pre-embedded in the sealing steel plate 6. The grouting pipes 7 extend into the gaps between the steel pipe segments 5 and the main tunnel segments 1. In this embodiment, the sealing is carried out in stages during the cutting process. After each section of the steel pipe segment 5 is cut within a range of approximately 30° to 45°, the area is immediately sealed and pre-embedded grouting pipes 7 are installed. In this method, by decomposing the large-area, high-risk exposure operation into multiple small-scale, controllable closed operation units, a section is cut and sealed, forming a dynamic and proactive construction safety protection structure, which can effectively avoid the occurrence of safety accidents during the construction period. The sealing steel plate 6 adopts an annular steel plate 61 and reinforcing angle steel 62. The annular steel plate 61 is welded between the steel pipe segment 5 and the portal steel ring 4, and the reinforcing angle steel 62 is welded to the annular steel plate 61 and the portal steel ring 4. The grouting pipes 7 are pre-embedded in the annular steel plate 61. The thickness of the annular steel plate 61 and the reinforcing angle steel 62 is at least 10 mm. The grouting pipe 7 is... Seamless steel pipes are embedded in the annular steel plate 61 at 15° intervals along the circumference.

[0031] 5. After all areas are sealed, single-component cement grout is injected into the gap between the steel pipe segment 5 and the main tunnel segment 1 through the pre-embedded grouting pipe 7 to form a solidified body 8. This solidified body 8, together with the sealing steel plate 6, constitutes a permanent sealing structure. The double sealing barrier formed by the solidified body 8 and the sealing steel plate 6 not only ensures safety and reliability during the construction phase but also provides long-term, highly reliable waterproofing protection for tunnel operation, effectively solving the potential for water leakage at the connection point.

[0032] VI. Tie the reinforcing bars of the portal ring beam 3 to the portal steel ring 4 and steel pipe segment 5, and weld the reinforcing bars of the portal ring beam 3 to the portal steel ring 4 and steel pipe segment 5 respectively, with a welding height of not less than 8mm. Simultaneously with tying the reinforcing bars of the portal ring beam 3, pre-embed DN60 embedded steel pipes and other embedded parts for pipeline wiring. The reinforcing bars of the portal ring beam 3 are composed of HRB400 main bars with diameters of 22mm, 20mm, and 16mm, and HPB300 stirrups with a diameter of 12mm. By welding the reinforcing bars of the portal ring beam 3 to the portal steel ring 4 and steel pipe segment 5 respectively, the three are rigidly connected into a whole, working synergistically to effectively increase the overall structural strength of the connection area.

[0033] VII. Finally, the formwork is erected and C35 concrete is poured to form the “lining” portal ring beam 3 structure, which is not less than 500mm wide and whose inner arc surface is smooth and flush with the inner wall of the main tunnel 1 segment, so that the portal ring beam 3 does not intrude into the construction limit of the main tunnel 1, effectively ensuring the width of the evacuation platform and the laying space of cables and pipelines in the tunnel.

[0034] The above-described embodiments are merely illustrative of this utility model. Any equivalent embodiments made by those skilled in the art without departing from the technical features disclosed in this utility model, and without departing from the technical features of this utility model, shall still fall within the scope of the technical features of this utility model.

Claims

1. A mechanically constructed portal ring beam structure for a connecting passage, comprising a main tunnel and a connecting passage, wherein an opening is pre-reserved on the segments of the main tunnel, a portal steel ring is pre-embedded in the opening, and the connecting passage connects to the opening, characterized in that: The connecting passage uses steel segments at the opening, which are cut to a length that does not intrude into the construction clearance of the main tunnel. A sealing steel plate is installed in the gap between the steel segment and the portal steel ring, and the gap between the steel segment and the main tunnel segment is grouted to form a solidified body. There is an overlap section between the steel segment and the portal steel ring, on which portal ring beam reinforcement is tied. The portal ring beam reinforcement is then welded to both the portal steel ring and the steel segment. A portal ring beam is formed by casting a formwork around the reinforcement. The inner arc surface of the portal ring beam is flush with the inner wall of the main tunnel segment and does not intrude into the construction clearance of the main tunnel.

2. The mechanical method for constructing a portal ring beam structure for a connecting passageway according to claim 1, characterized in that: The connecting passage consists of inlet ring segments and outlet ring segments at the opening, both made of Q355B grade steel. The solidified body is formed by single-liquid cement grout. The width of the portal ring beam is not less than 500mm.

3. The mechanical method for constructing a portal ring beam structure for a connecting passageway according to claim 1, characterized in that: The steel pipe segment has ribs and a back plate. The cut parts of the steel pipe segment are the ribs and the back plate. The uncut parts of the steel pipe segment have cavities filled with micro-expansion cement. The overlap length between the steel pipe segment and the portal steel ring is not less than 100mm.

4. The mechanical method for constructing a portal ring beam structure for a connecting passageway according to claim 1, characterized in that: The sealing steel plate includes an annular steel plate and reinforcing angle steel. The annular steel plate is welded between the steel pipe segment and the portal steel ring, and the reinforcing angle steel is welded to the annular steel plate and the portal steel ring. The thickness of the annular steel plate and the reinforcing angle steel is at least 10 mm. A grouting pipe is pre-embedded in the annular steel plate. Seamless steel pipes are pre-embedded at equal intervals around the circumference at 15° angles.

5. The mechanical method for constructing a portal ring beam structure for a connecting passageway according to claim 1, characterized in that: The welding height of the portal ring beam reinforcement is not less than 8mm; the portal ring beam reinforcement is also equipped with embedded steel pipes and embedded parts for pipeline wiring in the tunnel; the portal ring beam reinforcement is composed of HRB400 main bars with diameters of 22mm, 20mm and 16mm and HPB300 stirrups with a diameter of 12mm.

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