Open cut cable tunnel four-way well and arrangement method of high-voltage cable of open cut cable tunnel four-way well

Abstract

The invention relates to an open-cut cable tunnel four-way well and a high-voltage cable arrangement method thereof, and belongs to the field of municipal engineering or electric power engineering. The four-way well is of a three-section structure of a conventional tunnel, a tunnel deepening part and a tunnel cable crossing part, a cross-shaped steel structure overhaul walkway, a top plate fixing top hanging bracket structure and a bottom plate fixing bottom support structure are arranged in the four-way well, and water collecting pits are formed in the corners of a bottom plate. High-voltage cables form top and bottom cable layers through the hanging bracket and the support, layered cross laying is achieved, and the maintenance walkway guarantees safe passing and maintenance operation of personnel. The high-voltage cable tunnel node realizes separation of the pedestrian path and the cable channel, avoids the water accumulation risk, improves the laying and maintenance convenience, and is compact in structure, good in economy and suitable for construction of high-voltage cable tunnel nodes.

Description

Technical Field

[0001] This invention relates to the technical field of municipal engineering or power engineering, specifically to a four-way manhole for open-cut cable tunnels and a method for arranging high-voltage cables thereon. Background Technology

[0002] In cable tunnel engineering, the four-way manhole serves as a core node for cable branching, turning, and personnel maintenance; its structural design directly impacts project safety and ease of operation and maintenance. Two main solutions exist in current technology, but both have significant drawbacks: One type is the existing technology, such as the State Grid's commonly designed module schemes D-1, D-3, and D-23, which adopt a structure with a flush floor and uniform dimensions for all four sides of the passageway. Although this scheme allows for easy construction by matching the excavation depth of the foundation pit with that of the adjacent tunnel, when cables are laid across the four sides of the tunnel, cable crossings will occur within a height range of 2.0m to 3.0m inside the shaft, reducing the height of the personnel passage space to below 1.4m, seriously affecting passage safety; at the same time, when cable branch elevations conflict, the laying difficulty is extremely high.

[0003] Another type is like Figure 1 The partially sunken four-way well scheme in the integrated utility tunnel project shown meets the needs of pipeline crossings and personnel passage by partially sunken the intersections. However, this scheme has two major problems: First, personnel cannot directly operate at the bottom when inspecting pipelines, requiring the addition of large staircases or platforms, which increases the difficulty of inspection; second, areas with abundant groundwater levels are prone to water accumulation, and even with water pumps, equipment failure may still prevent the water from being drained, creating a vicious cycle in which maintenance personnel cannot access the area for repairs.

[0004] Existing related patents, such as "A Four-Way Sewage Pipe Crossing Node Structure" (ZL201621390560.3), focus on the problem of sewage pipe crossings, but do not involve the coordinated optimization of high-voltage cable laying and personnel passage. "A Four-Way Power Access Node Crossing Node" (ZL202021955742.7) adopts a three-layer pipe gallery structure, which realizes the four-way power compartment function, but the structure is complex, the investment is large, and it does not solve the core pain points of water accumulation and cable crossing occupying passage space.

[0005] Therefore, there is an urgent need for a method for the layout of open-cut cable tunnel four-way manholes and their cables that can effectively separate pedestrian passages from cable passages, avoid the risk of water accumulation, and simplify construction and maintenance processes. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method for arranging the four-way manhole of an open-cut cable tunnel and its high-voltage cables to solve the aforementioned problems.

[0007] This invention provides the following technical solution: A four-way manhole for an open-cut cable tunnel includes four sequentially connected conventional branch tunnels, a tunnel deepening section, and a cable crossing section. The conventional tunnel is connected to the external passages on all four sides. The height of the passage in the deepened part of the tunnel is increased to no less than 1.9m to allow personnel passage and to separate the cable into a top slab crossing section and a bottom slab bending crossing section. The tunnel cable crossing section is located in the middle of the four-way shaft. Inside it is a steel structure maintenance walkway with the same elevation as the conventional tunnel floor. The steel structure maintenance walkway crosses the tunnel deepening section. The floor of the tunnel cable crossing section is equipped with a water collection pit, and a bottom support structure for supporting the cable is fixed on the floor. The top plate of the tunnel cable crossing section is fixed with a top hanger structure for suspending the cable.

[0008] Furthermore, the steel structure maintenance walkway is cross-shaped and includes a grating panel and a supporting frame; The grating is laid on top of the support frame, which is formed by welding channel steel and fixed to the bottom plate of the tunnel cable crossing section. The height of the steel structure maintenance walkway is consistent with the depth of the tunnel deepening section.

[0009] Furthermore, the top hanger structure includes a horizontal support, a vertical connector, a fixing base, and chemical bolts; The horizontal support is a channel steel, and the vertical connector is two angle steels arranged side by side. The angle steels and the channel steel are tightly attached back to back and then fixedly connected by bolts. The fixing seat is a rectangular steel plate, which is welded vertically to the top of the vertical connector. The fixing seat has 4 bolt holes, and the chemical bolt passes through the bolt holes to fix the fixing seat to the top plate of the four-way well. The top hanger structure is a prefabricated integrated structure in the factory and is fixed on site using chemical bolts and bolts.

[0010] Furthermore, the bottom support structure includes uprights, column feet, horizontal supports, and auxiliary uprights; The column is a rectangular hollow square tube or a hollow tube formed by welding interlocking channel steel. The column base is fixed to the bottom plate of the four-way well by chemical adhesive anchor bolts. The bottom of the column is welded and fixed to the column base. The horizontal supports are spaced apart along the height of the columns and are connected to the columns by welding or bolts. The auxiliary column is located outside the bottom horizontal support, and its bottom is fixed to the base plate by chemical adhesive anchor bolts, and its top is welded to the bottom horizontal support. The bottom support structure is a prefabricated integrated structure in the factory, and is fixed on site by chemically bonded anchor bolts and bolt assembly.

[0011] Furthermore, the width of the steel structure maintenance walkway is not less than 0.8m, and the width of the passageway in the deepened part of the tunnel is not less than 0.8m.

[0012] Furthermore, the water collection pit is located at the corner of the bottom plate of the tunnel cable crossing section, and the depth of the water collection pit is not less than 300mm.

[0013] This invention also discloses a high-voltage cable arrangement method based on the four-way manhole of any of the aforementioned open-cut cable tunnels, comprising the following steps: S1: The high-voltage cable is suspended from the top plate of the four-way well through the top hanger structure to form the top cable layer; and supported by the bottom bracket structure to the bottom plate of the four-way well to form the bottom cable layer; S2: According to the requirements of the laying direction, the high-voltage cable crosses or turns between the top cable layer and the bottom cable layer at the cable crossing part in the tunnel, and the cable bending radius meets the requirements of the power engineering construction specifications. S3: Maintenance personnel enter the deeper part of the tunnel through the conventional tunnel and inspect and maintain the cables in the top and bottom cable layers via the steel structure maintenance walkway. S4: Water accumulated inside the tunnel is diverted to a sump through the slope and discharged regularly.

[0014] Furthermore, in step S1, the vertical distance between the top cable layer and the steel structure maintenance walkway is not less than 0.5m, and the vertical distance between the bottom cable layer and the steel structure maintenance walkway is not less than 0.5m.

[0015] The present invention has the following beneficial technical effects: Precise matching of passage space requirements: Through a three-section structure and layered laying design, the problem of cables crossing and occupying passage space in the existing solution is completely solved; the walkway and the base plate are kept at the same elevation, avoiding the risk of water accumulation in the sunken structure, and greatly improving passage safety and comfort.

[0016] The cable laying is stable and reliable: the top hanger structure is fixed with chemical bolts, which is suitable for the characteristics of concrete roof and underground humid environment, ensuring the long-term stable suspension of high-voltage cables; the top and bottom cable layers are physically separated, which can cross and turn in any direction, and the brackets and hangers are all prefabricated in the factory, with high installation accuracy and cable bending radius in accordance with specifications, avoiding stress concentration.

[0017] Maintenance efficiency is significantly improved: the cross-shaped steel structure maintenance walkway covers the core area inside the well, allowing maintenance personnel to access the top, bottom and surrounding cables from all directions without the need for additional platform construction or climbing, greatly shortening maintenance time; the grating design takes into account both walking safety and maintenance visibility, further improving the convenience of operation and maintenance.

[0018] The project combines economic efficiency and practicality: its compact structural design eliminates the need for complex multi-layer tunnel construction, reducing the cost of foundation pit excavation and structural construction; the prefabricated supports and hangers facilitate on-site installation and shorten the construction cycle; the sump design simplifies the drainage system, reduces operation and maintenance costs, and solves the problem of subsequent cable rewiring potentially obstructing maintenance access. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the four-way junction of an existing urban integrated utility tunnel. Figure 2 This is a diagram showing the cable arrangement diagonally across the top and bottom slabs; Figure 3 This is a layout diagram of the walkway at the bottom of the cable manhole; Figure 4 This is a layout diagram of the cable tunnel and its deepened section (AA section); Figure 5 This is a layout diagram (CC section) of the cable tunnel and its deepened section. Figure 6 This is a schematic diagram of the layout of the four-way well crane support (BB section).

[0020] The attached figures are labeled as follows: 1. Conventional tunnel; 2. Deepened section of tunnel; 3. Cable crossing section of tunnel; 4. Steel structure maintenance walkway; 5. Sump pit; 6. Bottom support structure; 61. Column; 62. Column base; 63. Horizontal support; 64. Auxiliary column; 7. Top hanging structure; 71. Horizontal support component; 72. Vertical connector. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1 The core of the open-cut cable tunnel four-way shaft of the present invention consists of four sequentially connected conventional tunnels 1, tunnel deepening section 2, and tunnel cable crossing section 3. The components work together to realize the functions of cable laying and personnel maintenance. Conventional Tunnel 1 connects with the four external passages, serving as the basic path for cable and personnel passage. Its structural dimensions are compatible with conventional cable tunnels, ensuring compatibility between construction and use.

[0023] The tunnel deepening section 2 is located between the conventional tunnel 1 and the tunnel cable crossing section 3. The height of the passage is increased to no less than 1.9m and the width of the passage is no less than 0.8m. This not only meets the requirements for personnel passage space, but also separates the cable into the top plate crossing section and the bottom plate bending crossing section, avoiding the cable crossing and occupying the passage space.

[0024] The tunnel cable crossing section 3 is located in the middle of the four-way shaft. Inside it, a steel structure maintenance walkway 4 is set up. The steel structure maintenance walkway 4 is cross-shaped and includes a grating plate and a support frame. The grating plate is laid on top of the support frame. The support frame is made of channel steel welded and fixed to the bottom plate of the tunnel cable crossing section 3. The height of the steel structure maintenance walkway 4 is consistent with the depth of the tunnel deepening section 2 and the elevation of the bottom plate of the conventional tunnel 1. It crosses the tunnel deepening section 2, making it convenient for maintenance personnel to reach various areas inside the shaft.

[0025] The top plate of the tunnel cable crossing section 3 is fixed with a top hanger structure 7. The top hanger structure 7 includes a horizontal support 71, a vertical connector 72, a fixing seat, and chemical bolts. The horizontal support 71 is a channel steel, and the vertical connector 72 consists of two angle steels arranged side by side. The angle steel and the channel steel are tightly attached back to back and then fixed together by bolts. The fixing seat is a rectangular steel plate, which is welded vertically to the top of the vertical connector 72. The fixing seat has 4 bolt holes. Chemical bolts pass through the bolt holes to fix the fixing seat to the top plate of the four-way manhole. The top hanger structure 7 is a prefabricated integrated structure in the factory and is fixed on site by chemical bolts and bolt assembly. It is used to suspend cables to form a top cable layer.

[0026] The bottom plate of the tunnel cable crossing section 3 is fixed with a bottom support structure 6. The bottom support structure 6 includes columns 61, column feet 62, horizontal supports 63, and auxiliary columns 64. The columns 61 are rectangular hollow square tubes or hollow tubes welded together with interlocking channel steel. The column feet 62 are fixed to the bottom plate of the four-way manhole by chemical adhesive anchor bolts. The bottom of the columns 61 is welded to the column feet 62. The horizontal supports 63 are spaced along the height direction of the columns 61 and are connected to the columns 61 by welding or bolts. The auxiliary columns 64 are located outside the bottom horizontal supports 63. The bottom of the auxiliary columns 64 is fixed to the bottom plate by chemical adhesive anchor bolts, and the top is welded to the bottom horizontal supports 63. The bottom support structure 6 is a prefabricated integrated structure in the factory and is fixed on site by chemical adhesive anchor bolts and bolts to support the cables and form the bottom cable layer.

[0027] A water collection pit 5 is installed on the bottom plate of the cable crossing section 3 in the tunnel. The water collection pit 5 is located at the corner of the bottom plate and has a depth of not less than 300mm. It is used to collect water accumulated in the tunnel for subsequent drainage.

[0028] Example 2 Based on the open-cut cable tunnel four-way shaft described in Embodiment 1, the high-voltage cable arrangement is carried out according to the following steps: The high-voltage cable is suspended from the top plate of the four-way well through the top hanger structure 7 to form the top cable layer; and supported by the bottom bracket structure 6 to the bottom plate of the four-way well to form the bottom cable layer; wherein the vertical distance between the top cable layer and the steel structure maintenance walkway 4 is not less than 0.5m, and the vertical distance between the bottom cable layer and the steel structure maintenance walkway 4 is not less than 0.5m, so as to reserve sufficient space for maintenance operations.

[0029] According to the requirements of the laying direction, the high-voltage cable crosses or turns between the top cable layer and the bottom cable layer at the cable crossing section 3 in the tunnel. During the crossing and turning process, the bending radius of the cable strictly meets the power engineering construction specifications to avoid affecting the performance of the cable due to improper bending.

[0030] Maintenance personnel enter the tunnel's deeper section 2 through the conventional tunnel 1, and then inspect and maintain the cables in the top and bottom cable layers via the steel structure maintenance walkway 4. The grating's structural design does not obstruct the maintenance view, making it easy for personnel to observe the cable's operating status and carry out maintenance work.

[0031] Water accumulated inside the tunnel is diverted to the water collection pit 5 via a pre-set slope. The water in the water collection pit 5 is drained regularly to prevent water accumulation from affecting personnel passage and equipment operation.

[0032] The embodiments described above are merely illustrative of specific implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A four-way manhole for open-cut cable tunnels, characterized in that, It includes four side branch conventional tunnels (1), a tunnel deepening section (2), and a tunnel cable crossing section (3) that are connected in sequence. The conventional tunnel (1) is connected to the external passages on all four sides. The height of the passage in the tunnel deepening section (2) is increased to no less than 1.9m, which is used for personnel passage and to separate the cable into the top plate crossing section and the bottom plate bending crossing section. The tunnel cable crossing section (3) is located in the middle of the four-way shaft. Inside it is a steel structure maintenance walkway (4) with the same elevation as the bottom plate of the conventional tunnel (1). The steel structure maintenance walkway (4) crosses the tunnel deepening section (2). The bottom plate of the tunnel cable crossing section (3) is provided with a water collection pit (5), and a bottom support structure (6) for supporting the cable is fixed on the bottom plate. The top plate of the tunnel cable crossing section (3) is fixed with a top hanger structure (7) for suspending the cable.

2. A four-way manhole for an open-cut cable tunnel according to claim 1, characterized in that, The steel structure maintenance walkway (4) is cross-shaped, including a grating plate and a support frame; The grating is laid on the top of the support frame. The support frame is formed by welding channel steel and fixed to the bottom plate of the tunnel cable crossing part (3). The height of the steel structure maintenance walkway (4) is consistent with the depth of the tunnel deepening part (2).

3. The four-way shaft for open-cut cable tunnels according to claim 1, characterized in that, The top hanger structure (7) includes a horizontal support (71), a vertical connector (72), and fixing and chemical bolts; The horizontal support (71) is a channel steel, and the vertical connector (72) is two angle steels arranged side by side. The angle steels and the channel steel are tightly attached back to back and then fixedly connected by bolts. The fixing seat is a rectangular steel plate, which is vertically welded to the top of the vertical connector (72). The fixing seat has 4 bolt holes, and the chemical bolt passes through the bolt holes to fix the fixing seat to the top plate of the four-way well. The top hanger structure (7) is a prefabricated integrated structure in the factory and is fixed on site by chemical bolts and bolt assembly.

4. The four-way shaft for open-cut cable tunnels according to claim 1, characterized in that, The bottom support structure (6) includes a column (61), a column base (62), a horizontal support (63), and an auxiliary column (64). The column (61) is a rectangular hollow square tube or a hollow tube formed by welding interlocking channel steel. The column foot (62) is fixed to the bottom plate of the four-way well by chemical adhesive anchor bolts. The bottom of the column (61) is welded and fixed to the column foot (62). The horizontal support (63) is spaced apart along the height direction of the column (61) and is connected to the column (61) by welding or bolts; The auxiliary column (64) is located outside the bottom horizontal support (63), and its bottom is fixed to the base plate by chemical adhesive anchor bolts, and its top is welded to the bottom horizontal support (63). The bottom support structure (6) is a prefabricated integrated structure in the factory and is fixed on site by chemical adhesive anchor bolts and bolt assembly.

5. The four-way shaft for open-cut cable tunnels according to claim 1, characterized in that, The width of the steel structure maintenance walkway (4) is not less than 0.8m, and the width of the tunnel deepening section (2) is not less than 0.8m.

6. The four-way shaft for open-cut cable tunnels according to claim 1, characterized in that, The water collection pit (5) is located at the corner of the bottom plate of the tunnel cable crossing section (3), and the depth of the water collection pit (5) is not less than 300mm.

7. A method for arranging high-voltage cables in a four-way manhole of an open-cut cable tunnel as described in any one of claims 1-6, characterized in that, Includes the following steps: S1: The high-voltage cable is suspended from the top plate of the four-way well through the top hanger structure (7) to form the top cable layer; and supported on the bottom plate of the four-way well through the bottom support structure (6) to form the bottom cable layer; S2: According to the requirements of the laying direction, the high-voltage cable crosses or turns between the top cable layer and the bottom cable layer at the cable crossing part (3) in the tunnel, and the cable bending radius meets the requirements of the power engineering construction specification. S3: Maintenance personnel enter the tunnel deepening section (2) through the conventional tunnel (1) and inspect and maintain the cables in the top and bottom cable layers via the steel structure maintenance walkway (4); S4: Water accumulated in the tunnel is diverted to the sump (5) by the slope and discharged regularly.

8. The high-voltage cable arrangement method according to claim 7, characterized in that, In step S1, the vertical distance between the top cable layer and the steel structure maintenance walkway (4) is not less than 0.5m, and the vertical distance between the bottom cable layer and the steel structure maintenance walkway (4) is not less than 0.5m.

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