Prefabricated temporary support for pilot tunnel excavation

Abstract

The utility model provides a prefabricated temporary support for pilot tunnel excavation, which comprises a vertical temporary support, a plurality of groups of breast boards, a central connecting structure and a transverse temporary support, and the breast boards are longitudinally arranged on the vertical temporary support; the central connecting structure is arranged at the bottom of the vertical temporary support and is fixedly connected with the vertical temporary support through a bolt; the transverse temporary support is arranged on one side of the center connecting structure and fixedly connected with the center connecting structure through bolts, and the transverse temporary support is perpendicular to the vertical temporary support. The prefabricated temporary support does not need cast-in-place concrete, supporting is fast, and the overall construction efficiency is high. And construction procedures can be reduced, the project construction period can be shortened, construction resources can be saved, the engineering cost is reduced, disturbance of temporary structure dismantling to the stratum is reduced, potential engineering risks are effectively reduced, and good engineering application and popularization value is achieved.

Description

Technical Field

[0001] This utility model relates to the field of tunnel construction technology, specifically to a prefabricated temporary support for the excavation of a pilot tunnel. Background Technology

[0002] In recent years, my country's transportation sector has experienced sustained and rapid development. The accelerating urbanization process has led to a dramatic increase in urban population and vehicle ownership, exacerbating urban traffic congestion and posing significant challenges to residents' daily travel and the efficient operation of cities. To effectively alleviate traffic pressure and improve transportation efficiency, the demand for large-section tunnels is growing daily. Large-section tunnels, with their spacious passageways, can significantly increase traffic capacity, playing an indispensable and crucial role in alleviating traffic congestion, whether in the construction of urban transportation hubs or the expansion of major transportation routes connecting cities.

[0003] At the same time, underground engineering construction technology is also constantly being innovated and improved. In the process of in-depth development of urban underground space, such as the construction of underground shopping malls, underground parking lots, underground rail transit, and tunnel construction under complex geological conditions, construction methods such as single-sidewall method, double-sidewall method, CD method, and CRD method are widely used in response to different geological structures, surrounding rock conditions and construction environments.

[0004] Among the various construction methods mentioned above, the construction of temporary supports plays a crucial role in ensuring construction safety and tunnel stability. However, the current construction methods for temporary supports have many drawbacks that cannot be ignored. At present, most temporary supports are constructed by pouring concrete on-site. The construction process generally involves first erecting a steel arch frame, accurately installing the steel arch frame according to the tunnel's design outline and stress requirements, then laying a steel mesh, binding the steel bars to the steel arch frame at certain intervals and arrangements to enhance the overall structural strength, and finally performing shotcrete operations, using shotcrete equipment to evenly spray concrete onto the steel arch frame and steel mesh to form a robust temporary support structure.

[0005] However, traditional support methods are slow and inefficient. Dismantling them not only wastes a lot of resources, which is inconsistent with the current trend of green construction, but also affects the stability of the original structure, leading to the collapse of the tunnel structure. In view of this, a prefabricated temporary support for the excavation of the pilot tunnel is proposed to solve the above problems. Utility Model Content

[0006] To address the shortcomings of existing technologies, this utility model proposes a prefabricated temporary support for the excavation of a pilot tunnel, thereby solving the technical problems mentioned in the background art, where current temporary supports are mostly constructed by on-site concrete pouring, i.e., using steel arch frames, steel mesh, and shotcrete. This construction is slow, inefficient, and inconvenient to dismantle, and dismantling it can affect the stability of the original tunnel structure.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a prefabricated temporary support for the excavation of a pilot tunnel, comprising:

[0008] Vertical temporary supports;

[0009] The retaining plates are arranged in multiple sets longitudinally, and all of them are placed on the vertical temporary supports;

[0010] A central connecting structure is located at the bottom of the vertical temporary support and is fixedly connected to it by bolts; and

[0011] A lateral temporary support is provided on one side of the central connecting structure and fixed to it by bolts, and the lateral temporary support is arranged perpendicular to the vertical temporary support.

[0012] Furthermore, the vertical temporary support includes:

[0013] The first I-beam is arranged in two sets at intervals, and the multiple sets of retaining plates are arranged between the two sets of the first I-beams; and

[0014] The first connecting base is disposed at the end of the first I-beam and is connected to the central connecting structure.

[0015] Furthermore, the lateral temporary support includes a second I-beam, and a second connecting base is provided at the end of the second I-beam, the second connecting base being connected to the central connecting structure.

[0016] Furthermore, the central connection structure includes:

[0017] Two sets of transverse support connecting steel plates are arranged at intervals, and the first connecting base is connected to one set of transverse support connecting steel plates by bolts.

[0018] Two sets of vertical support connecting steel plates are arranged at intervals and spliced ​​with the horizontal support connecting steel plates to form a square frame. The second connecting base is bolted to one set of the vertical support connecting steel plates.

[0019] The central connecting angle steel is provided in four sets, which are located at the four inner corners of the square frame, and are bolted to one set of horizontal support connecting steel plates and the vertical support connecting steel plates.

[0020] Furthermore, multiple sets of stop blocks are arranged at intervals on the inner side of the first I-beam. The stop blocks at the top, bottom, and middle positions are bolted to the inner side of the first I-beam, while the remaining sets of stop blocks are welded to the beam of the first I-beam. There are gaps between the multiple sets of stop blocks and the inner wall of the first I-beam, and the retaining plate is set in the gaps.

[0021] Furthermore, multiple sets of placement slots are welded onto the beam of the first I-beam, and a set of reinforcing cross braces is placed in every two sets of placement slots.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The main body of the prefabricated temporary support is a steel structure. Before construction, the prefabricated temporary support is designed and processed according to the design. After excavation, the initial support is constructed in time, and the prefabricated temporary support is installed at the same time. According to the construction sequence, the vertical temporary support and the horizontal temporary support are connected into a whole by the central connecting structure. At the same time, retaining plates are installed for soil retention. There is no need to pour concrete on site, the support is quick and the overall construction efficiency is high.

[0024] Before the next stage of construction, the connecting bolts between the various parts of the prefabricated temporary support can be removed to complete the dismantling of the prefabricated temporary support. The overall dismantling is convenient and quick, which can not only reduce construction procedures and shorten the project period, but also save construction resources, reduce project costs, reduce the disturbance of the stratum to the temporary structure dismantling, and effectively reduce potential project risks. It has good engineering application and promotion value. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of this utility model, the accompanying drawings used in the specific embodiments will be briefly described below. In all the drawings, the elements or parts are not necessarily drawn to scale.

[0026] Figure 1 A three-dimensional structural diagram of a prefabricated temporary support for the excavation of a branch tunnel provided by this utility model;

[0027] Figure 2 This is a schematic diagram of the vertical temporary support in a prefabricated temporary support for the excavation of a pilot tunnel according to the present invention.

[0028] Figure 3 This is a schematic diagram of the retaining plate and reinforcing cross brace in a prefabricated temporary support for the excavation of a branch tunnel according to the present invention.

[0029] Figure 4 This is a schematic diagram of the central connection structure in a prefabricated temporary support for the excavation of a branch tunnel according to the present invention;

[0030] Figure 5This is a schematic diagram of the transverse temporary support in a prefabricated temporary support for the excavation of a pilot tunnel according to the present invention;

[0031] Figure label:

[0032] 1. Vertical temporary support; 2. Horizontal temporary support; 3. Central connection structure; 4. Retaining plate; 5. Reinforcing cross brace; 6. First connecting base; 7. Stop block; 8. Second connecting base; 9. Placement groove; 10. First I-beam; 11. Horizontal support connecting steel plate; 12. Vertical support connecting steel plate; 13. Central connecting angle steel; 14. Second I-beam. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above application content.

[0034] Example:

[0035] like Figure 1 As shown, this utility model provides a prefabricated temporary support for the excavation of a pilot tunnel, including a vertical temporary support 1, a central connecting structure 3, and a horizontal temporary support 2. Multiple sets of retaining plates 4 are arranged longitudinally on the vertical temporary support 1. The central connecting structure 3 is located at the bottom of the vertical temporary support 1 and is fixedly connected to it by bolts. The horizontal temporary support 2 is located on one side of the central connecting structure 3 and is fixedly connected to it by bolts, and the horizontal temporary support 2 is arranged perpendicularly to the vertical temporary support 1.

[0036] Before construction, temporary supports were designed and fabricated according to the design span of the underground structure. Based on the specific dimensions of different construction tunnels, temporary supports of corresponding specifications were designed and fabricated, and the central connecting structure 3 was assembled off-site. Then, the pilot tunnels were excavated according to the design plan. After the designed advance of the first pilot tunnel was completed, the temporary supports and initial tunnel supports were promptly constructed. During the construction of the temporary supports, the central connecting structure 3 was first inserted, and then the vertical temporary supports 1 and the horizontal temporary supports 2 were installed using bolts. Finally, multiple sets of retaining plates 4 were assembled to form a temporary support structure, which served as retaining walls. Subsequent pilot tunnels were then excavated and supported according to the construction plan. The subsequently constructed temporary supports were bolted to the central connecting structure 3 of the previously constructed temporary supports, so that the temporary supports between the pilot tunnels together formed a complete prefabricated temporary support. When proceeding to the next stage of construction, the connecting bolts between the various parts were removed in the reverse order of installation, which quickly and easily dismantled the temporary supports and facilitated subsequent reuse.

[0037] like Figure 1 , 4 As shown in Figure 5, in this embodiment, the vertical temporary support 1 includes two sets of spaced-apart first I-beams 10, and multiple sets of retaining plates 4 are arranged between the two sets of first I-beams 10. A first connecting base 6 is provided at the end of each first I-beam 10, and the first connecting base 6 is connected to the central connecting structure 3. The horizontal temporary support 2 includes a second I-beam 14, and a second connecting base 8 is provided at the end of each second I-beam 14, and the second connecting base 8 is connected to the central connecting structure 3. The central connecting structure 3 includes two sets of horizontally arranged supporting connecting steel plates 11 spaced apart. The first connecting base 6 is bolted to one of the sets of horizontally arranged supporting connecting steel plates 11. It also includes two sets of vertically arranged supporting connecting steel plates 12 spaced apart. The two sets of vertically arranged supporting connecting steel plates 12 and the horizontally arranged supporting connecting steel plates 11 are spliced ​​together to form a square frame. The second connecting base 8 is bolted to one of the sets of vertically arranged supporting connecting steel plates 12. A central connecting angle steel 13 is provided at each of the four inner corners of the square frame. The central connecting angle steel 13 is bolted to one of the sets of horizontally arranged supporting connecting steel plates 11 and the vertically arranged supporting connecting steel plates 12.

[0038] Among them, the first I-beam 10, the second I-beam 14, the transverse support connecting steel plate 11, the vertical support connecting steel plate 12, and the central connecting angle steel 13 are all steel structures to improve the load-bearing capacity of the prefabricated temporary support. The central connecting angle steel 13 is connected to the transverse support connecting steel plate 11 and the vertical support connecting steel plate 12, which not only enables the assembly of the central connection structure 3, but also allows for the pre-support of the transverse support connecting steel plate 11 and the vertical support connecting steel plate 12 in the adjacent central connection structure 3 during the next construction.

[0039] like Figures 1 to 3 As shown, in this embodiment, multiple sets of blocks 7 are arranged at intervals on the inner side of the first I-beam 10. The blocks 7 at the top, bottom and middle positions are bolted to the inner side of the first I-beam 10, and the remaining multiple sets of blocks 7 are welded to the beam of the first I-beam 10. There are gaps between the multiple sets of blocks 7 and the inner wall of the first I-beam 10, and the retaining plate 4 is set in the gap.

[0040] Multiple sets of retaining plates 4 can be stably installed using multiple sets of stop blocks 7, ensuring stable support for the soil. The retaining plates 4 can be easily disassembled by removing the bolted sets of stop blocks 7. Furthermore, multiple sets of placement slots 9 are welded onto the first I-beam 10, with a set of reinforcing cross braces 5 placed within every two sets of placement slots 9. These reinforcing cross braces 5 enhance the stability of the prefabricated temporary support structure.

[0041] The specific usage and beneficial effects of this utility model are as follows:

[0042] The main body of the prefabricated temporary support is a steel structure. Before construction, the prefabricated temporary support is designed and processed according to the design. After excavation, the initial support is constructed in time, and the prefabricated temporary support is installed at the same time. According to the construction sequence, the vertical temporary support 1 and the horizontal temporary support 2 are connected into a whole by the central connecting structure 3. At the same time, the retaining plate 4 is installed for soil retention. There is no need to pour concrete on site, the support is quick and the overall construction efficiency is high.

[0043] Before the next stage of construction, the connecting bolts between the various parts of the prefabricated temporary support can be removed to complete the dismantling of the prefabricated temporary support. The overall dismantling is convenient and quick, which can not only reduce construction procedures and shorten the project period, but also save construction resources, reduce project costs, reduce the disturbance of the stratum to the temporary structure dismantling, and effectively reduce potential project risks. It has good engineering application and promotion value.

[0044] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. It will be apparent to those skilled in the art that this utility model is not limited to the details of the exemplary embodiments described above. Modifications or improvements can be made to this utility model, which is obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of this utility model fall within the scope of protection claimed by this utility model.

Claims

1. A precast temporary support for excavation of a cross- drift, characterized in that, The utility model relates to a temporary support structure for retaining soil, comprising: vertical temporary supports (1); earth-retaining plates (4) arranged in multiple groups longitudinally and on the vertical temporary supports (1); a central connecting structure (3) arranged at the bottom of the vertical temporary supports (1) and fixedly connected to the vertical temporary supports (1) by bolts; and horizontal temporary supports (2) arranged on one side of the central connecting structure (3) and fixedly connected to the central connecting structure (3) by bolts, and the horizontal temporary supports (2) are arranged perpendicularly to the vertical temporary supports (1).

2. A precast temporary support for excavation of a cross adit according to claim 1, wherein The vertical temporary supports (1) comprise: first I-shaped steel (10) arranged in two groups, and the earth-retaining plates (4) are arranged between the two groups of first I-shaped steel (10); and first connecting bases (6) arranged at the ends of the first I-shaped steel (10) and connected to the central connecting structure (3).

3. A precast temporary support for the excavation of a crossheading according to claim 2, characterised in that: The horizontal temporary supports (2) comprise second I-shaped steel (14), and the ends of the second I-shaped steel (14) are provided with second connecting bases (8) connected to the central connecting structure (3).

4. A precast temporary support for the excavation of a crossheading according to claim 3, characterised in that, The central connecting structure (3) comprises: horizontal support connecting steel plates (11) arranged in two groups, and the first connecting bases (6) are connected to one of the horizontal support connecting steel plates (11) by bolts; vertical support connecting steel plates (12) arranged in two groups and connected to the horizontal support connecting steel plates (11) to form a square frame, and the second connecting bases (8) are connected to one of the vertical support connecting steel plates (12) by bolts; and central connecting angle steels (13) arranged in four groups and located at the inner four corners of the square frame and connected to one of the horizontal support connecting steel plates (11) and the vertical support connecting steel plates (12) by bolts.

5. A precast temporary support for excavation of a cross- adit according to claim 2, wherein: The first I-shaped steel (10) is provided with multiple groups of stoppers (7) arranged at intervals on the inner side, and the stoppers (7) at the top, bottom and middle positions are fixedly connected to the inner side of the first I-shaped steel (10) by bolts, and the remaining groups of stoppers (7) are fixedly connected to the beam of the first I-shaped steel (10) by welding, and there is a gap between the stoppers (7) and the inner wall of the first I-shaped steel (10), and the earth-retaining plates (4) are arranged in the gap.

6. A precast temporary support for excavation of a cross- adit according to claim 2, wherein: The beam of the first I-shaped steel (10) is provided with multiple groups of placing grooves (9), and each two groups of placing grooves (9) are provided with one group of reinforcing cross braces (5).

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