Temporary support node

Abstract

The utility model relates to a temporary supporting joint which comprises a plurality of vertical profile steel supports, a plurality of supporting base plates, a plurality of longitudinal connecting sleeves and a plurality of longitudinal connecting ribs. The supporting base plates comprise top base plates and bottom base plates which are in one-to-one correspondence, the top base plates and the bottom base plates are located in top surrounding rock and bottom surrounding rock at the intersection of the underground excavation air duct and the protective tunnel main body enclosure structure correspondingly, and the top base plates and the corresponding bottom base plates are located in the same vertical plane; the vertical profile steel support is arranged in the vertical direction, the horizontal section of the vertical profile steel support is in an I shape, and the top end and the bottom end of the vertical profile steel support are welded to the top base plate and the bottom base plate respectively. The longitudinal connecting sleeve is welded on the web plate, the longitudinal connecting rib is inserted into the longitudinal connecting sleeve, and the longitudinal connecting rib is arranged along the horizontal direction. According to the utility model, the air duct can be synchronously excavated on the outer side of the protective tunnel side wall, and the excavation and backfill work amount is reduced, so that the manufacturing cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of underground engineering construction, and in particular to a temporary support node. Background Technology

[0002] Tunnel structures are a common structural form used in national defense and civil air defense projects, characterized by strong protective capabilities, low load on the main retaining structure, and large internal shelter capacity. From a protective perspective, tunnel structures should be constructed whenever possible, provided they meet the functional requirements and the geological conditions permit. In the design of tunnel structures, ventilation ducts are placed in different locations depending on the protected area. At the entrances and exits, considering protective requirements, ventilation ducts are typically buried outside the entrance retaining structure and encased in a layer of concrete for protection.

[0003] Typically, the buried ventilation ducts are circular steel plate ducts with a diameter generally not exceeding 2 meters. For the pre-embedding of the ducts, a matching underground ventilation duct needs to be excavated beforehand. There are generally two construction schemes for this underground ventilation duct: 1. First, excavate and support the duct according to the cross-sectional dimensions of the main retaining structure's opening, and then excavate and support the underground ventilation duct outside the retaining structure separately according to the process requirements; 2. Excavate and support the duct simultaneously according to the larger cross-sectional dimensions of the main retaining structure and the underground ventilation duct. Scheme 1 has problems such as requiring secondary excavation and support of the surrounding rock outside the sidewall, and the need to partially break down the initial support of the main retaining structure before duct excavation; Scheme 2 has problems such as requiring larger cross-sectional dimensions of the opening for excavation and support, resulting in larger excavation and backfilling work, the need to strengthen the initial support parameters, and increased safety hazards due to the larger excavation span. All of these will increase the project cost.

[0004] Therefore, it is necessary to provide a temporary support node to simultaneously excavate ventilation ducts on the outside of the protective tunnel sidewall, thereby reducing the amount of excavation and backfilling work and thus reducing costs. Utility Model Content

[0005] The purpose of this utility model is to provide a temporary support node that allows for the simultaneous excavation of ventilation ducts on the outside of the protective tunnel sidewall, thereby reducing the amount of excavation and backfilling work and thus lowering the cost.

[0006] To address the problems existing in the prior art, this utility model provides a temporary support node. The temporary support node is located at the intersection of the main retaining structure of the underground ventilation duct and the protective tunnel. The temporary support node includes: multiple vertical steel supports, multiple support pads, multiple longitudinal connecting sleeves, and multiple longitudinal connecting bars.

[0007] The support pads include a one-to-one corresponding top pad and bottom pad. The top pad and bottom pad are located in the top and bottom surrounding rock at the intersection of the main retaining structure of the underground ventilation duct and the protective tunnel, respectively, and the top pad and the corresponding bottom pad are located in the same vertical plane.

[0008] The vertical steel support is set in the vertical direction. The horizontal cross section of the vertical steel support is in the shape of "I". The two parallel surfaces in the vertical steel support are called parallel plates. The vertical surface connecting the two parallel plates is called the web plate. The top and bottom of the vertical steel support are welded to the top pad plate and the bottom pad plate, respectively.

[0009] The longitudinal connecting sleeve is welded to the web plate, and the longitudinal connecting rib is inserted into the longitudinal connecting sleeve, and the longitudinal connecting rib is arranged in the horizontal direction.

[0010] Optionally, in the temporary support node, there is a spacing between each vertical steel support and a spacing between each longitudinal connecting bar.

[0011] Optionally, in the temporary support node, the top pad is in close contact with the top surrounding rock, and the bottom pad is in close contact with the bottom surrounding rock.

[0012] Optionally, the temporary support node is a removable structure.

[0013] Compared with the prior art, this utility model has the following advantages:

[0014] (1) Excavate ventilation ducts simultaneously on the outside of the protective tunnel sidewalls, and reduce the amount of excavation and backfilling work, thereby reducing the cost.

[0015] (2) It solves the safety hazards caused by the increase in the excavation span during synchronous excavation construction.

[0016] (3) By building temporary support nodes, the problem of increasing the initial support parameters due to the increase in excavation span is avoided. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the synchronous excavation cross-section provided for an embodiment of the present utility model;

[0018] Figure 2 A schematic diagram of a temporary support node provided in an embodiment of this utility model;

[0019] Figure 3 A schematic diagram showing the connection between the vertical steel support and the support plate provided in this embodiment of the utility model;

[0020] Figure 4 This is a schematic diagram of the installation of the longitudinal connecting ribs provided in an embodiment of the present utility model;

[0021] Figure 5 A horizontal cross-sectional view of the vertical steel support provided in this embodiment of the utility model when it is installed vertically;

[0022] Figure 6 A schematic cross-sectional view of the concrete covering the duct provided in this embodiment of the utility model.

[0023] 1-Supporting pad; 2-Vertical steel support; 3-Longitudinal connecting sleeve; 4-Longitudinal connecting reinforcement; 5-Excavation outline; 6-Shotcrete layer; 7-Anchor bolt; 8-Ventilation duct; 9-Main enclosure structure; 10-Underground ventilation duct; 11-Secondary lining reinforcement; 12-Outer concrete. Detailed Implementation

[0024] The specific embodiments of this utility model will now be described in more detail with reference to the accompanying drawings. The advantages and features of this utility model will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of this utility model.

[0025] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0026] Both existing solutions will increase the project cost.

[0027] To address the problems existing in the prior art, this utility model provides a temporary support node, which is located at the intersection of the underground ventilation duct 10 and the main retaining structure 9 of the protective tunnel. For example... Figure 1-6 The temporary support node includes: multiple vertical steel supports 2, multiple support pads 1, multiple longitudinal connecting sleeves 3, and multiple longitudinal connecting bars 4;

[0028] Support plate 1 includes a corresponding top plate and a bottom plate, which are located in the top and bottom surrounding rock at the intersection of the underground ventilation duct 10 and the main retaining structure 9 of the protective tunnel, respectively. (Refer to...) Figure 1 The top of the vertical steel support 2 is in close contact with the top surrounding rock, and the bottom of the vertical steel support 2 is in close contact with the bottom surrounding rock. The top pad and the corresponding bottom pad are located in the same vertical plane.

[0029] The vertical steel support 2 is installed vertically. The horizontal cross-section of the vertical steel support 2 is I-shaped. Two parallel surfaces in the vertical steel support 2 are called parallel plates, and the vertical surface connecting the two parallel plates is called the web. The top and bottom ends of the vertical steel support 2 are welded to a top pad and a bottom pad, respectively (e.g., ...). Figure 3 (as shown);

[0030] The longitudinal connecting sleeve 3 is welded to the web plate, and the longitudinal connecting rib 4 is inserted into the longitudinal connecting sleeve 3, with the longitudinal connecting rib 4 arranged in a horizontal direction. In one embodiment, such as Figure 4 As shown, the webs of adjacent vertical steel supports 2 are parallel, and the ends of the longitudinal connecting bars 4 are bent and inserted into the longitudinal connecting sleeves 3. In this case, the longitudinal connecting sleeves 3 are perpendicular to the longitudinal connecting bars 4.

[0031] Preferred, such as Figure 2 As shown, there is a spacing S between each vertical steel support 2, and a spacing D between each longitudinal connecting bar 4 (not shown in the figure).

[0032] Preferably, the temporary support nodes are removable structures.

[0033] This utility model also provides a method for simultaneous excavation of protective tunnels and ventilation ducts, employing the aforementioned temporary support nodes, as referenced. Figure 1-6 The synchronous excavation method includes the following steps:

[0034] S1: Based on the cross-sectional dimensions of the burr hole of the main retaining structure 9 of the protective tunnel, the engineering geological conditions and hydrogeological conditions, calculate the anchor spraying support parameters and secondary lining parameters of the burr hole of the main retaining structure 9. Also calculate the anchor spraying support parameters of the burr hole of the underground ventilation duct 10 outside the sidewall of the main retaining structure 9, the thickness of the concrete 12 covering the ventilation duct 8 and the thickness of the sprayed concrete layer 6, etc.

[0035] S2: Based on the diameter of the proposed pre-buried air duct (8) Figure 1 Based on the requirements for the DN), the thickness of the concrete 12 surrounding the duct 8 (usually 200 mm), and the thickness of the shotcrete layer 6, the location of the embedded duct 8 and the corresponding excavation outline 5 of the underground ventilation duct 10 are determined. Generally, the duct 8 is laid close to the ground surface, and the distance from the center of the duct 8 to the excavation outline 5 of both the ground surface and the underground ventilation duct 10 is ≥DN / 2+200 mm (location diagram shown). Figure 1 (As shown). Anchor bolts 7, which serve as supports, are installed around the outer contour line 5 of the excavation.

[0036] S3: Determine the required support height of the vertical steel support 2 based on the proposed excavation outline 5 (e.g., Figure 1As shown in H), it is proposed to set the temporary support node at the intersection of the underground ventilation duct 10 and the main retaining structure 9, and calculate the parameters of the temporary support node based on the engineering geological conditions; the parameters of the temporary support node include: the thickness (e.g., 15 mm), length (e.g., 200 mm), and width (e.g., 200 mm) of the support pad 1; the spacing S between each vertical steel support 2; the thickness of the web plate (… Figure 5 t in Chinese w (indicated), the width of the two parallel plates ( Figure 5 (represented by b) is the distance between the outer edges of the two parallel plates. Figure 5 The value is represented by h (e.g., 180 mm); the spacing D between each longitudinal connecting bar 4; and the diameter of the longitudinal connecting bar 4.

[0037] S4: Based on the outer contour line 5 of the main retaining structure 9 and the underground ventilation duct 10, the rough sections of the main retaining structure 9 and the ventilation duct are excavated simultaneously. The top and bottom pads of the support pad 1 are pre-embedded in the surrounding rock at the intersection, ensuring that the top and bottom pads correspond one-to-one and are located in the same vertical plane. When pre-embedding the top and bottom pads of the support pad 1, remove any loose material at their contact points to ensure that the top of the vertical steel support 2 is in close contact with the top surrounding rock and the bottom of the vertical steel support 2 is in close contact with the bottom surrounding rock. After pre-embedding the support pad 1, the anchor spraying support is carried out promptly.

[0038] S5: According to the longitudinal arrangement spacing S of the proposed vertical steel support 2, erect the vertical steel support 2 and weld it to the top and bottom pads. The welding quality must meet the relevant specifications.

[0039] S6: According to the proposed spacing requirement D for the longitudinal connecting ribs 4, weld the longitudinal connecting sleeve 3 onto the web of the vertical steel support 2. After welding, insert the longitudinal connecting ribs 4 and spot weld the longitudinal connecting ribs 4 and the sleeve. The welding quality must meet the relevant specifications.

[0040] S7: Reference Figure 6 After the temporary support nodes are completed, the duct 8 is buried at the designated location. Then, concrete of grade C20 or higher is used to pour the outer concrete 12 wall of the duct 8, ensuring that the thickness of the outer concrete 12 wall of the duct 8 meets the previously specified requirements. Before burying the duct 8, anti-corrosion and fire prevention measures are implemented.

[0041] S8: After the concrete reaches the design strength, remove the temporary support nodes as needed, arrange the secondary lining reinforcement 11, and pour the secondary lining.

[0042] In summary, compared with the prior art, this utility model has the following advantages:

[0043] (1) Excavate ventilation ducts simultaneously on the outside of the protective tunnel sidewalls, and reduce the amount of excavation and backfilling work, thereby reducing the cost.

[0044] (2) It solves the safety hazards caused by the increase in the excavation span during synchronous excavation construction.

[0045] (3) By building temporary support nodes, the problem of increasing the initial support parameters due to the increase in excavation span is avoided.

[0046] The above are merely preferred embodiments of this utility model and do not constitute any limitation on this utility model. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and contents disclosed in this utility model without departing from the scope of the technical solutions of this utility model shall still fall within the protection scope of this utility model.

Claims

1. A temporary support node, characterized in that, The temporary support node is located at the intersection of the main retaining structure of the underground ventilation duct and the protective tunnel. The temporary support node includes: multiple vertical steel supports, multiple support pads, multiple longitudinal connecting sleeves, and multiple longitudinal connecting bars. The support pads include a one-to-one corresponding top pad and bottom pad. The top pad and bottom pad are located in the top and bottom surrounding rock at the intersection of the main retaining structure of the underground ventilation duct and the protective tunnel, respectively, and the top pad and the corresponding bottom pad are located in the same vertical plane. The vertical steel support is set in the vertical direction. The horizontal cross section of the vertical steel support is in the shape of "I". The two parallel surfaces in the vertical steel support are called parallel plates. The vertical surface connecting the two parallel plates is called the web plate. The top and bottom of the vertical steel support are welded to the top pad plate and the bottom pad plate, respectively. The longitudinal connecting sleeve is welded to the web plate, and the longitudinal connecting rib is inserted into the longitudinal connecting sleeve, and the longitudinal connecting rib is arranged in the horizontal direction.

2. A temporary support node according to claim 1, characterised in that, There are gaps between the vertical steel supports and between the longitudinal connecting bars.

3. The temporary support node of claim 1, wherein, The top pad is in close contact with the top surrounding rock, and the bottom pad is in close contact with the bottom surrounding rock.

4. The temporary support node of claim 1, wherein, The temporary support nodes are removable structures.

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