A support structure for intersecting roadways and its construction method

Abstract

This invention relates to the field of underground tunnel support technology, and discloses a support structure for intersecting tunnels, including a fully enclosed steel arch frame (1) and anchor cable locks (5). The fully enclosed steel arch frame (1) includes a top arch (101), side pillars (102) connected to both ends of the top arch (101), a bottom arch connecting bracket (104) set on the middle and lower areas of the side pillars (102), and a bottom arch (103) connected to the bottom arch connecting bracket (104). The top arch (101), some of the side pillars (102), the bottom arch connecting bracket (104), and the bottom arch (103) can enclose and form a closed steel arch frame, and the side pillars (102) extending downward from the bottom arch connecting bracket (104) can be connected to the support leg foundation (2). This invention also discloses a construction method for the support structure of intersecting tunnels. The forming method of this invention is convenient to operate and has good performance.

Description

Technical Field

[0001] This invention relates to the field of underground tunnel support technology, specifically to a support structure for intersecting tunnels and its construction method. Background Technology

[0002] In the construction of mines, tunnels and underground projects, such as Figure 1 Intersecting roadways (such as the junction of a main roadway and a branch roadway) are prone to instability and failure due to their large excavation cross-section and complex stress redistribution, making them a key and challenging area for support. Traditional support methods, including single anchor-sprayed support, I-beam support, or partial concrete pouring, often fail to provide sufficient support strength and overall stability, especially under conditions of high ground pressure and weak, fractured surrounding rock. In such cases, the support structure is prone to failure, maintenance costs are high, and significant safety hazards exist.

[0003] In recent years, although some combined support technologies have emerged, such as "steel arch frame + shotcrete" and "steel arch frame + anchor cable," the following shortcomings still exist in their application in intersecting roadways: First, poor overall integrity: the bottom of the steel arch frame is not firmly connected to the foundation, easily leading to uneven settlement, causing the arch frame to twist and become unstable. Second, insufficient sealing: traditional steel arch frames mostly only support the roof and two sides, neglecting the support of the floor slab (bottom arch), making it difficult to control floor heave. Third, weak synergy: the steel arch frame and anchor cable system are mostly independently stressed, lacking an effective connection and synergistic working mechanism, and the support potential is not fully realized. Fourth, poor adaptability: insufficient adaptability to complex stress states such as high stress concentration and eccentric pressure at intersections.

[0004] In view of this, there is a need to provide a construction method for the support structure of intersecting roadways to solve or overcome the above-mentioned technical problems. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a support structure for intersecting roadways, which has high integrity, high strength, good sealing effect, high collaborative support capability, simple structure, convenient construction, and good performance.

[0006] Another technical problem to be solved by the present invention is to provide a construction method for the support structure of intersecting roadways. This construction method is applicable to the support of underground engineering roadways and can form a new type of support structure with high integrity, high strength, full enclosure and collaborative support capabilities. It is easy to operate and has good performance.

[0007] To solve the above-mentioned technical problems, one aspect of the technical solution proposed by the present invention is as follows: A support structure for intersecting roadways includes a fully enclosed steel arch frame. The fully enclosed steel arch frame includes a top arch, side pillars connected to both ends of the top arch, a bottom arch connecting bracket located in the middle and lower regions on the side pillars, and a bottom arch connected to the bottom arch connecting bracket. The top arch, part of the side pillars, the bottom arch connecting bracket, and the bottom arch can enclose the steel arch frame to form a closed structure, and the side pillars extending downward from the bottom arch connecting bracket can be connected to the support leg foundation.

[0008] Preferably, the top arch is provided with a top arch connecting bracket at both ends, the top of the side pillar is provided with a side pillar top connecting bracket, and the bottom of the side pillar is provided with a side pillar bottom connecting bracket. The top arch connecting bracket and the side pillar top connecting bracket are connected by fasteners.

[0009] Preferably, the upper ends of the two side pillars are connected to a connecting beam, the upper surfaces of both ends of the connecting beam are connected to the top connecting bracket of the side pillar, and an interlayer concrete layer is provided above the connecting beam, which can connect the upper areas of two adjacent fully enclosed steel arch frames.

[0010] Preferably, the lower part of the fully enclosed steel arch frame is also provided with a subgrade tunnel floor, the upper surface of the subgrade tunnel floor is provided with a subgrade waterway ditch, and the bottom arch connecting support is located within the subgrade tunnel floor.

[0011] Preferably, the support structure for the intersecting roadway of the present invention further includes an anchor cable lock, wherein a side shotcrete layer is provided on the opposite side of the side support, the anchor cable lock is adapted to pass through the side support and the side shotcrete layer, and the end of the anchor cable lock away from the shotcrete extends to the outside of the side support.

[0012] Preferably, the anchor cable locks are symmetrically arranged on the side supports on both sides.

[0013] Another aspect of the present invention provides a technical solution: a construction method for a support structure of an intersecting roadway, comprising the following steps: Step S01: Excavate the intersecting tunnels according to the design requirements and trim the tunnel outlines; Step S02: Excavate and pour the support leg foundation at the bottom of the tunnel, and reserve the installation position of the side support column on the upper surface of the support leg foundation; Step S03: Prefabricate fully enclosed steel arch frame; Step S04: Connect the bottom connecting bracket of the side support column to the support leg foundation; Step S05: Drill holes in the side support and install anchor cable locks; Step S06: Install a top plate on the connecting beams of two adjacent fully enclosed steel arch frames, and spray concrete on the top plate to form an interlayer concrete layer; Step S07: Shot concrete sealing layer between the fully enclosed steel arch frame and the surrounding rock to fill the back gap and form an initial seal; Step S08: Pour the underlying tunnel floor, embed the bottom arch, and simultaneously spray concrete on the opposite sides of the side support to form a side sprayed concrete layer, thus completing the surface sealing. Step S09: Maintenance and quality inspection.

[0014] Preferably, the anchor cable lock has an inclination angle of 10-30°, a length of 6-15m, and a prestress of 100-200KN. The anchor cable lock passes directly through the side support through the opening structure or through the welded sleeve on the side support.

[0015] Preferably, the thickness of the concrete sealing layer is 80-150mm, and it is applied in two stages: initial spraying and re-spraying. An accelerator is added to the concrete forming the concrete sealing layer.

[0016] Preferably, the thickness of the underlying tunnel floor is 300-500mm, and it is provided with a drainage slope of not less than 3%.

[0017] Through the above technical solution, the support structure for intersecting roadways of the present invention includes a fully enclosed steel arch frame. The fully enclosed steel arch frame includes a top arch, side supports connecting both ends of the top arch, a bottom arch connecting bracket located in the middle and lower regions on the side supports, and a bottom arch connected to the bottom arch connecting bracket. The top arch, part of the side supports, the bottom arch connecting bracket, and the bottom arch can enclose and form a closed steel arch frame structure, and the side supports extending downwards from the bottom arch connecting bracket can be connected to the outrigger foundation. The support structure for intersecting roadways of the present invention, through the fully enclosed steel arch frame and the coordinated support of anchor cables, forms a dual load-bearing system combining the arch frame and internal anchors. It has a simple structure, is easy to construct, and has good performance.

[0018] Other advantages of the present invention and the technical effects of preferred embodiments will be further described in the following detailed description. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a specific embodiment of the intersecting lanes described in this invention; Figure 2 This is a schematic diagram of a specific embodiment of the support structure for the intersecting roadway described in this invention, showing the specific structure after construction and its positional relationship with the overlying roadway. Figure 3 This is a schematic diagram of a specific embodiment of the support structure for intersecting roadways described in this invention. Figure 4 This is a schematic diagram of a specific embodiment of the side support column and the bottom connecting bracket of the side support column described in this invention; Figure 5 This is a schematic diagram of a specific embodiment of the side support, bottom arch, and bottom arch connecting bracket described in this invention; Figure 6 This is a structural schematic diagram of a specific embodiment of the top arch, side pillars, and connecting beams described in this invention; Figure 7 This is a schematic diagram of a specific embodiment of the anchor cable lock described in this invention; Figure 8 This is a schematic flowchart of the construction method for the support structure of the intersecting roadway described in this invention.

[0020] Explanation of reference numerals in the attached figures 1. Fully enclosed steel arch frame; 101. Top arch; 102. Side support column; 103. Bottom arch; 104. Bottom arch connecting bracket; 105. Top arch connecting bracket; 106. Side support column top connecting bracket; 107. Connecting beam; 108. Side support column bottom connecting bracket; 109. Top plate; 2. Outrigger foundation; 3. Interlayer concrete layer; 4. Underground tunnel floor; 401. Underground waterway ditch; 5. Anchor cable lock; 501. Anchor cable self-aligning ball; 502. Anchor cable lock body; 6. Side shotcrete layer; 7. Overlying roadway; 701. Concrete floor slab of the overlying roadway; 8. Lower alleyway. Detailed Implementation

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.

[0022] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features.

[0024] like Figures 1 to 7 As shown, the present invention provides a support structure for intersecting lanes, including a fully enclosed steel arch frame 1 and an anchor cable lock 5. The fully enclosed steel arch frame 1 includes a top arch 101, side pillars 102 connected to both ends of the top arch 101, a bottom arch connecting bracket 104 disposed on the middle and lower regions of the side pillars 102, and a bottom arch 103 connected to the bottom arch connecting bracket 104. The top arch 101, part of the side pillars 102, the bottom arch connecting bracket 104, and the bottom arch 103 can be enclosed to form a closed steel arch frame structure, and the side pillars 102 extending downward from the bottom arch connecting bracket 104 can be connected to the support leg foundation 2.

[0025] In this invention, a dual load-bearing system combining an outer arch and an inner anchor is adopted. Specifically, it includes a fully enclosed steel arch frame 1 and anchor cable locks 5. The fully enclosed steel arch frame 1 includes a top arch 101, side pillars 102, a bottom arch connecting bracket 104, and a bottom arch 103. The top arch 101, a portion of the side pillars 102, the bottom arch connecting bracket 104, and the bottom arch 103 enclose the fully enclosed steel arch frame 1. The other end of the side pillar 102 extends from both ends of the bottom arch 103 and connects to the support leg foundation 2 to fix the fully enclosed steel arch frame 1. The fully enclosed steel arch frame 1 can provide overall support for the surface of the roadway in the intersecting roadway. At the same time, anchor cable locks 5 are installed through the side pillars 102. After passing through the side pillars 102, the anchor cable locks 5 are inserted obliquely into the surrounding rock. Thus, after the anchor cable locks 5 are tensioned, the pressure of the surrounding rock can be transmitted to the deeper parts through the anchor cable locks 5. Thus, the two complement each other to form a dual support system, namely the synergistic support effect of the overall surface support of the tunnel and the deep anchoring of the surrounding rock.

[0026] Furthermore, the lower ends of the side pillars 102 extending from both ends of the bottom arch 103 are connected to the leg foundation 2, forming an integral structure with the fully enclosed steel arch 1 and the leg foundation 2. The fully enclosed steel arch 1 forms a closed ring-shaped load-bearing structure. The force from the middle can be reversed through the top arch 101, reflecting the pressure from the top of the tunnel back along the vertical direction of the tangent of the top arch 101. The entire top arch 101 forms a divergent force-bearing layout structure. In addition, the top arch 101 is formed as an outwardly convex semi-circular arc structure, which can also effectively increase the force-bearing surface, enabling the fully enclosed steel arch 1 to withstand more pressure from the top of the tunnel.

[0027] In a preferred embodiment of the present invention, the top arch 101 is provided with a top arch connecting bracket 105 at both ends, the side pillar 102 is provided with a side pillar top connecting bracket 106 at the top end, and the side pillar 102 is provided with a side pillar bottom connecting bracket 108 at the bottom. The top arch connecting bracket 105 and the side pillar top connecting bracket 106 are connected by fasteners.

[0028] The fully enclosed steel arch frame 1 of the present invention adopts a segmented assembly and overall hoisting installation method. The length of each segment is preferably no more than 5m, which greatly reduces the installation difficulty and labor intensity of workers. The top arch 101, the side support 102 and the bottom arch 103 are connected by flange bolts.

[0029] like Figure 6 As shown in the figure, in a specific embodiment of the present invention, the ends of the top arch 101 are welded to the top arch connecting brackets 105, and the top of the side pillar 102 is welded to the top of the side pillar top connecting bracket 106. The top arch connecting bracket 105 is provided with a plurality of fastener connecting holes, and the side pillar top connecting bracket 106 is provided with corresponding fastener connecting holes, thereby forming a detachable connection between the top arch 101 and the side pillar 102. This allows the overall structure to be broken down into parts, which is not only convenient for processing, production and transportation, but also convenient for on-site construction and installation.

[0030] In a specific embodiment of the present invention, the bottom connecting bracket 108 of the side support column serves as the bottom rigid support of the side support column 102, which can fix the entire fully enclosed steel arch frame 1 to the support leg foundation 2. This ensures the installation stability of the bottom of the entire fully enclosed steel arch frame 1 and the uniformity of force transmission, and effectively prevents settlement and slippage. Of course, a connecting structure can also be set on the support leg foundation 2 during pre-casting to facilitate subsequent fixing.

[0031] In a preferred embodiment of the present invention, the upper ends of the two side pillars 102 are connected to a connecting beam 107, the upper surfaces of both ends of the connecting beam 107 are connected to the top connecting bracket 106 of the side pillars, and an interlayer concrete layer 3 is provided above the connecting beam 107, which can connect the upper areas of two adjacent fully enclosed steel arch frames 1.

[0032] As a specific embodiment of the present invention, from Figure 2As can be seen, an interlayer concrete layer 3 is provided above the connecting beam 107, which can completely enclose the top arch 101, forming a steel-concrete composite structure, thereby effectively and significantly improving the support strength and rigidity of the top slab. Furthermore, the connecting beam 107 is welded from the arching line of the top arch 101, which enhances the out-of-plane stability of the fully enclosed steel arch frame 1 and simultaneously serves as a skeletal reinforcement for the interlayer concrete layer 3.

[0033] In a preferred embodiment of the present invention, the lower part of the fully enclosed steel arch frame 1 is provided with a lower tunnel floor 4, the upper surface of the lower tunnel floor 4 is provided with a lower waterway ditch 401, and the bottom arch connecting bracket 104 is located in the lower tunnel floor 4.

[0034] As a specific embodiment of the present invention, the lower part of the fully enclosed steel arch frame 1 is filled with a subgrade roadway floor 4, and the bottom arch 103 is located within the subgrade roadway floor 4, thereby forming an integral bottom plate constraint on the lower part of the fully enclosed steel arch frame 1, which can effectively suppress the deformation of the bottom bulge.

[0035] In a preferred embodiment of the present invention, a side shotcrete layer 6 is provided on the opposite side of the side support 102, and the anchor cable 5 is adapted to pass through the side support 102 and the side shotcrete layer 6, with one end of the anchor cable 5 away from the shotcrete layer 6 extending to the outside of the side support 102.

[0036] As a specific embodiment of the present invention, the shotcrete layer 6, the interlayer concrete layer 3, the support leg foundation 2, and the underlying tunnel floor 4 can all be made of high-strength, micro-expansion, or fiber-reinforced concrete to improve their crack resistance, impermeability, and durability. Furthermore, the shotcrete layer 6 and the interlayer concrete layer 3, together with the fully enclosed steel arch frame 1, form a closed support structure, effectively filling the gap between the fully enclosed steel arch frame 1 and the tunnel inner wall, preventing localized rockfall, and enabling the fully enclosed steel arch frame 1 to form a unified load-bearing body with the surrounding rock.

[0037] In a preferred embodiment of the present invention, the anchor cable lock 5 is symmetrically arranged on the side support pillars 102 on both sides.

[0038] In a specific embodiment of the present invention, the anchor cable lock 5 can be connected to the side support 102 through a pre-drilled hole or a welded anchor cable sleeve, etc. One end of the anchor cable lock 5 extends into the deep part of the surrounding rock for rock mass anchoring and has good stability. The anchor cable lock 5 is constructed by drilling a hole. After the anchor cable lock 5 is inserted into the hole, grouting material is used for grouting. The grouting material is preferably cement grout or resin anchoring agent. The tensioning equipment is preferably a hydraulic jack.

[0039] like Figure 7 As shown, the anchor cable lock 5 includes an anchor cable lock body 502 and an anchor cable self-aligning ball 501 disposed on the anchor cable lock body 502. The anchor cable lock body 502 is arranged along the roadway dip, so that after the anchor cable lock 5 is tensioned, the surrounding rock pressure is transmitted to the deep part of the surrounding rock through the anchor cable lock 5, which can effectively perform tensioning and locking. At the same time, it can also achieve a fully enclosed surface support structure through the fully enclosed steel arch frame 1. The two work together to form a dual load-bearing system of "outer arch + inner anchor".

[0040] In another aspect, the present invention provides a construction method for a support structure of an intersecting roadway, comprising the following steps: Step S01: Excavate the intersecting tunnels according to the design requirements and trim the tunnel outlines; Step S02: Excavate and pour the support leg foundation 2 at the bottom of the tunnel, and reserve the installation position of the side support column 102 on the upper surface of the support leg foundation 2; Step S03: Prefabricate fully enclosed steel arch frame 1; Step S04: Connect the bottom connecting bracket 108 of the side support column to the support leg foundation 2; Step S05: Drill holes in the side support 102 and install the anchor cable lock 5; Step S06: Install a top plate 109 on the connecting crossbeams 107 on the two adjacent fully enclosed steel arch frames 1, and spray concrete on the top plate 109 to form an interlayer concrete layer 3. Step S07: Shot concrete sealing layer between the fully enclosed steel arch frame 1 and the surrounding rock to fill the back gap and form an initial seal; Step S08: Pour the underlying tunnel floor 4, embed the bottom arch 103, and simultaneously spray concrete on the opposite sides of the side support 102 to form a side sprayed concrete layer 6, thus completing the surface sealing. Step S09: Maintenance and quality inspection.

[0041] In a preferred embodiment of the present invention, the anchor cable lock 5 has an inclination angle of 10-30°, a length of 6-15m, and a prestress of 100-200KN. The anchor cable lock 5 passes directly through the side support 102 through the opening structure or through the side support 102 through the welded sleeve on the side support 102.

[0042] In a preferred embodiment of the present invention, the thickness of the shotcrete layer 6 is 80-150mm, and it is applied in two stages: initial spraying and re-spraying. An accelerator is added to the concrete forming the sealing layer. After the re-spraying, the total thickness reaches the design value, and the spraying pressure is 0.4-0.7MPa. The curing time for the shotcrete layer 6 is 7-14 days. Quality inspection includes concrete strength, anchor cable prestress, and steel arch deformation.

[0043] In a preferred embodiment of the present invention, the thickness of the underlying tunnel floor 4 is 300-500mm, and it is provided with a drainage slope of not less than 3%.

[0044] The support structure for intersecting roadways of the present invention has the following four beneficial effects: First, high integrity: The fully enclosed steel arch frame 1 is integrally cast with the interlayer concrete layer 3 and the side sprayed concrete layer 6. The top arch 101 and bottom arch 103 of the fully enclosed steel arch frame 1 are embedded in the concrete, thus forming a steel-concrete integrated and fully enclosed load-bearing structure, which can effectively resist uneven settlement and eccentric pressure.

[0045] Second, high-strength support: The combined structure of steel and concrete, along with the synergistic effect of the anchor cable lock, can significantly improve the support's load-bearing capacity and resistance to deformation.

[0046] Third, the fully enclosed support structure: the top arch 101, the side support column 102 and the bottom arch 103 form a single fully enclosed steel arch frame 1. The two adjacent fully enclosed steel arch frames 1 are connected by the top plate 109 and then the interlayer concrete layer 3 is poured. Combined with the side shotcrete concrete layer 6 and the underlying roadway floor 4, a fully enclosed support structure covering the top plate, the two sides and the bottom plate is formed, which can completely suppress the floor heave and the loosening of the surrounding rock.

[0047] Fourth, convenient construction: The fully enclosed steel arch frame is modularly designed, which facilitates on-site installation and adjustment and is suitable for more complex and varied geological conditions.

[0048] As a relatively preferred embodiment of the support structure for the cross-lane of the present invention, it includes a fully enclosed steel arch frame 1 and an anchor cable lock 5. The fully enclosed steel arch frame 1 includes a top arch 101, side pillars 102 connected to both ends of the top arch 101, a bottom arch connecting bracket 104 disposed in the middle and lower region of the side pillars 102, and a bottom arch 103 connected to the bottom arch connecting bracket 104. The top arch 101, part of the side pillars 102, the bottom arch connecting bracket 104, and the bottom arch 103 can enclose and form a closed steel arch frame structure, and the side pillars 102 extending downward from the bottom arch connecting bracket 104 can be connected to the support leg foundation 2. The top arch 101 has top arch connecting brackets 105 at both ends, the side pillars 102 have top side pillar connecting brackets 106 at their top ends, and bottom side pillar connecting brackets 108 at their bottom ends. The top arch connecting brackets 105 and the side pillar top connecting brackets 106 are connected by fasteners. A connecting beam 107 is connected to the upper ends of the two side pillars 102. The upper surfaces of both ends of the connecting beam 107 are connected to the side pillar top connecting brackets 106. An interlayer concrete layer 3 is provided above the connecting beam 107, which connects the upper areas of two adjacent fully enclosed steel arch frames 1. A lower tunnel floor 4 is also provided at the bottom of the fully enclosed steel arch frame 1. A lower waterway ditch 401 is provided on the upper surface of the lower tunnel floor 4, and the bottom arch connecting bracket 104 is located within the lower tunnel floor 4. A side shotcrete layer 6 is provided on the opposite side of the side support 102. The anchor cable 5 is adapted to pass through the side support 102 and the side shotcrete layer 6. The end of the anchor cable 5 away from the shotcrete layer 6 extends to the outside of the side support 102. The anchor cable 5 is symmetrically arranged on the side supports 102 on both sides.

[0049] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0050] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0051] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A support structure for intersecting roadways, characterized in that, The system includes a fully enclosed steel arch frame (1) and an anchor cable lock (5). The fully enclosed steel arch frame (1) includes a top arch (101), side pillars (102) connected to both ends of the top arch (101), a bottom arch connecting bracket (104) located in the middle and lower area on the side pillars (102), and a bottom arch (103) connected to the bottom arch connecting bracket (104). The top arch (101), part of the side pillars (102), the bottom arch connecting bracket (104), and the bottom arch (103) can enclose the steel arch frame to form a closed structure. The side pillars (102) extending downward from the bottom arch connecting bracket (104) can be connected to the leg foundation (2).

2. The support structure for intersecting roadways according to claim 1, characterized in that, The top arch (101) is provided with a top arch connecting bracket (105) at both ends, the top of the side pillar (102) is provided with a side pillar top connecting bracket (106), and the bottom of the side pillar (102) is provided with a side pillar bottom connecting bracket (108). The top arch connecting bracket (105) and the side pillar top connecting bracket (106) are connected by fasteners.

3. The support structure for intersecting roadways according to claim 2, characterized in that, The upper ends of the two side pillars (102) are connected to a connecting beam (107). The upper surfaces of both ends of the connecting beam (107) are connected to the top connecting bracket (106) of the side pillar. An interlayer concrete layer (3) is provided above the connecting beam (107). The interlayer concrete layer (3) can connect the upper areas of the two adjacent fully enclosed steel arch frames (1).

4. The support structure for intersecting roadways according to claim 1, characterized in that, The lower part of the fully enclosed steel arch frame (1) is also provided with a subgrade tunnel floor (4), and the upper surface of the subgrade tunnel floor (4) is provided with a subgrade waterway ditch (401). The bottom arch connecting bracket (104) is located inside the subgrade tunnel floor (4).

5. The support structure for intersecting roadways according to any one of claims 1 to 4, characterized in that, The side support (102) has a side shotcrete layer (6) on the opposite side, and the anchor cable lock (5) is adapted to pass through the side support (102) and the side shotcrete layer (6), with one end of the anchor cable lock (5) away from the shotcrete layer (6) extending to the outside of the side support (102).

6. The support structure for intersecting roadways according to claim 5, characterized in that, The anchor cable lock (5) is symmetrically arranged on the side pillars (102) on both sides.

7. A construction method for a support structure of an intersecting roadway, characterized in that, Includes the following steps: Step S01: Excavate the intersecting tunnels according to the design requirements and trim the tunnel outlines; Step S02: Excavate and pour the support leg foundation (2) at the bottom of the tunnel, and reserve the installation position of the side support column (102) on the upper surface of the support leg foundation (2); Step S03: Prefabricate fully enclosed steel arch frame (1); Step S04: Connect the bottom connecting bracket (108) of the side support column to the support leg foundation (2); Step S05: Drill holes in the side support (102) and install the anchor cable lock (5); Step S06: Install a top plate (109) on the connecting beam (107) on the two adjacent fully enclosed steel arch frames (1), and spray concrete on the top plate (109) to form an interlayer concrete layer (3). Step S07: Spray a concrete sealing layer between the fully enclosed steel arch frame (1) and the surrounding rock to fill the back gap and form an initial seal; Step S08: Pour the underlying tunnel floor (4), embed the bottom arch (103), and at the same time spray concrete on the opposite sides of the side support (102) to form a side sprayed concrete layer (6) to complete the surface sealing. Step S09: Maintenance and quality inspection.

8. The construction method of the support structure for the intersecting roadway according to claim 7, characterized in that, The anchor cable lock (5) has an inclination angle of 10-30°, a length of 6-15m, and a prestress of 100-200KN. The anchor cable lock (5) passes directly through the side support (102) through the opening structure or through the welded sleeve on the side support (102).

9. The construction method of the support structure for the intersecting roadway according to claim 8, characterized in that, The thickness of the concrete sealing layer is 80-150mm, and it is applied in two stages: initial spraying and re-spraying. A quick-setting agent is added to the concrete forming the concrete sealing layer.

10. A construction method for the support structure of an intersecting roadway according to any one of claims 7 to 9, characterized in that, The thickness of the underpass floor (4) is 300-500mm, and it is provided with a drainage slope of not less than 3%.

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