A hyperbolic arch tunneling structure for soft strata, featuring pre-support and post-breakage excavation.

Abstract

This utility model discloses a hyperbolic arched tunneling structure for soft soil strata, designed to solve related problems in the construction of cross passages leading to the main tunnel in urban subway construction. By employing a pre-support, post-breakage arched tunneling method at the connection section between the construction cross passage and the main tunnel, the arch crown of the cross passage and main tunnel connection section is longitudinally aligned with the upward convex arc curve of the main tunnel arch crown. A pre-support, post-breakage steel portal frame, a portal grille steel frame, and a portal steel frame are installed at the arched entrance of the main tunnel. The main tunnel grille steel frame and main tunnel steel frame are then erected at the portal location for structural pouring. Compared with traditional structures, this utility model's cross passage and main tunnel connection section structure effectively improves the safety of the concealed works of the cross passage leading to the main tunnel.

Description

Technical Field

[0001] This utility model belongs to the field of tunnel engineering technology, specifically relating to a hyperbolic arch tunneling structure for soft strata, which involves pre-support and post-breakage tunneling. Background Technology

[0002] With the construction of urban subways, cut-and-cover stations are increasingly being used in urban rail transit. Cross passageway construction is an essential component of cut-and-cover station construction. Cross passageway construction generally uses two methods: gantry-type flat-roof entry and arched entry. Both methods are widely used in subway, railway tunnel, and highway tunnel construction projects. Because cross passageway construction is a concealed project, many factors affect its quality, making quality control difficult. Furthermore, due to issues such as changes in the load-bearing system, safety problems are more likely to occur here, including exceeding monitoring data limits, roof collapse, support frame deformation, and encroachment. Utility Model Content

[0003] This invention addresses the shortcomings of existing technologies by providing a hyperbolic arch tunneling structure for soft strata, characterized by pre-support and post-breakage excavation. This structure improves stability during tunnel construction, reduces surface subsidence, and ensures construction safety.

[0004] This utility model achieves this objective through the following technical solution:

[0005] A hyperbolic arch tunneling structure for soft strata, consisting of a standard section of the construction cross passage connecting the main tunnel and the excavation section of the main tunnel, wherein the arch of the construction cross passage in the section connecting the construction cross passage and the main tunnel presents an upward convex arc curve of the arch of the main tunnel in the longitudinal direction, forming a hyperbolic arch structure in both the horizontal and vertical directions.

[0006] The advanced support for the connection section between the construction cross passage and the main tunnel includes double rows of small guide pipes at the top and sidewall anchors;

[0007] The support for the connection between the construction cross passage and the main tunnel includes the construction cross passage grid steel frame and shotcrete structure. The support outline of the connection between the construction cross passage and the main tunnel adopts an arched top and straight sidewall design on the side closer to the main tunnel. The construction cross passage grid steel frame of the support for the connection between the construction cross passage and the main tunnel is arranged along the hyperbolic arched top.

[0008] In the support of the connection section between the construction cross passage and the main tunnel, the construction cross passage grid steel frame is equipped with a construction cross passage locking anchor at the cross section position on the outline of the main tunnel entrance excavation face. One end of the construction cross passage locking anchor is welded to the cross section of the cross passage grid steel frame. The main tunnel entrance is equipped with a main tunnel advanced middle pipe shed, which is located above the main tunnel support at the entrance position.

[0009] A first-support-then-break steel gantry is installed inside the support of the construction cross passage and the main tunnel connection section near the main tunnel. The main reinforcement of the construction cross passage grid steel frame in the support of the construction cross passage and the main tunnel connection section is welded at the junction of the first steel pad plate of the first-support-then-break steel gantry and the arch wall. The innermost outline of the first-support-then-break steel gantry is located on the outline line of the main tunnel entrance excavation face.

[0010] An opening-type steel frame is installed inside the pre-supported and then broken steel gantry frame, and an opening-type steel frame is installed inside the opening-type steel frame.

[0011] The main tunnel support includes the main tunnel grid steel frame and shotcrete structure and the main tunnel steel frame and shotcrete structure. The main tunnel grid steel frame and shotcrete structure is located on the side of the opening portal grid steel frame facing the main tunnel. The main tunnel steel frame and shotcrete structure is located on the side of the opening portal steel frame facing the main tunnel and is located on the inner side below the main tunnel grid steel frame and shotcrete structure. The main tunnel grid steel frame and shotcrete structure is located along the main tunnel steel frame and shotcrete structure facing the main tunnel.

[0012] The inner side of the main tunnel support structure is the main tunnel structure, and the inner side of the construction cross passage support is the construction cross passage secondary lining structure. The first-support-then-break steel portal frame, the opening door grid steel frame, and the opening door steel frame are all cast inside the construction cross passage secondary lining structure. The main tunnel structure and the construction cross passage secondary lining structure are equipped with a structural middle plate that isolates the upper and lower spaces.

[0013] The main tunnel support arch foot, the pre-support and post-break steel portal frame, the opening portal grid steel frame, and the opening portal steel frame are all erected on the rock surface after the soil above the main tunnel has been excavated.

[0014] Furthermore, the overall structure of the pre-supported and then broken steel gantry is as follows: a second steel pad is arranged inside the first steel pad, a first type of steel is welded between the first steel pad and the second steel pad, a third steel pad and a fourth steel pad are arranged inside the second steel pad, a second type of steel is welded between the third steel pad and the fourth steel pad, and the second steel pad and the third steel pad are connected by bolts.

[0015] Furthermore, the first and second steel sections are double-section I25a steel sections. The first steel section faces the longitudinal direction of the main tunnel and is evenly arranged circumferentially between the first and second steel pads. The second steel section faces perpendicular to the longitudinal direction of the main tunnel and is welded circumferentially to the third and fourth steel pads along the outline of the first-support-then-break steel gantry.

[0016] Furthermore, the double-row small guide pipes used in the construction cross passage are... The advanced small guide tubes are not less than 4.5m in length. The outer insertion angle of the two rows of small guide tubes is adjusted according to the curvature of the arch, and the overlap length is not less than 2m.

[0017] Furthermore, for the construction cross passage anchor bolts, two hollow anchor bolts are installed in each cross passage grid steel frame, with an anchor bolt length of not less than 6m.

[0018] Furthermore, the main tunnel adopts an advanced central pipe roof design. For pipe sheds, the external insertion angle is 1 to 3 degrees.

[0019] Furthermore, the number of main tunnel grid steel frames erected at the tunnel excavation entrance is 3 to 4.

[0020] Furthermore, steel plates are installed at the joint surfaces between the opening portal grating steel frame and the opening portal steel frame, and between the main tunnel grating steel frame and the main tunnel steel frame, and the two joint surface steel plates are connected by bolts.

[0021] Furthermore, longitudinal steel reinforcement is used to connect the steel frame of the opening portal grid with the steel frame of the main tunnel grid, and the steel frame of the opening portal with the steel frame of the main tunnel. The inner and outer sides of the steel reinforcement should be staggered.

[0022] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0023] The technical solution proposed in this utility model can solve the related problems of the construction of the cross passage of the underground subway station in urban subway construction. It adopts a double-curved arch tunneling structure with support and then breaking in soft strata. Compared with the traditional construction method, it can effectively improve the safety and construction efficiency of the hidden works of the cross passage into the main structure. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the construction cross passage in an embodiment of this utility model;

[0025] Figure 2 This is a schematic diagram of the overall structure of the main tunnel in the embodiment of this utility model;

[0026] Figure 3 for Figure 1 Enlarged view of a portion of point A in the middle;

[0027] Figure 4 This is a schematic diagram of the pre-supported and then broken steel gantry structure in an embodiment of this utility model.

[0028] The attached diagram is labeled as follows: 1-Double row of small guide pipes, 2-Side wall anchor bolts, 3-Construction cross passage grid steel frame, 4-Construction cross passage locking anchor bolts, 5-Main tunnel advanced central pipe shed, 6-Pre-support and then-breakable steel portal frame, 7-Opening portal grid steel frame, 8-Opening portal steel frame, 9-Main tunnel grid steel frame, 10-Main tunnel steel frame, 11-Construction cross passage secondary lining structure, 12-Main tunnel structure, 13-Structural middle plate, 601-First steel pad, 602-First steel section, 603-Second steel pad, 604-Third steel pad, 605-Second steel section, 606-Fourth steel pad. Detailed Implementation

[0029] Exemplary embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art. It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0030] See Figure 1-4 This utility model provides an embodiment of a hyperbolic arch tunneling structure for soft strata, which includes a construction cross passage connecting the standard section of the construction cross passage and the main tunnel. The arch of the construction cross passage connecting the construction cross passage and the main tunnel presents the upward convex arc curve of the main tunnel arch in the longitudinal direction, forming a hyperbolic arch structure in both the horizontal and vertical directions.

[0031] The advanced support for the connection section between the construction cross passage and the main tunnel includes double-row small guide pipes 1 at the top and sidewall anchors 2.

[0032] The support for the connection between the construction cross passage and the main tunnel includes the construction cross passage grid steel frame 3 and the shotcrete structure. The outline of the support for the connection between the construction cross passage and the main tunnel adopts an arched top and straight sidewall design on the side closer to the main tunnel. The construction cross passage grid steel frame 3 of the support for the connection between the construction cross passage and the main tunnel is arranged along the hyperbolic arched top.

[0033] In the support of the connection section between the construction cross passage and the main tunnel, the construction cross passage grid steel frame 3 is installed at the cross section of the main tunnel entrance excavation face outline. The construction cross passage locking anchor 4 is installed at one end and welded to the cross passage grid steel frame 3. The main tunnel entrance is equipped with a main tunnel advance middle pipe shed 5, which is located above the main tunnel support at the entrance.

[0034] A pre-supported and then broken steel gantry 6 is installed inside the support of the construction cross passage and the main tunnel connection section near the main tunnel side. The main reinforcement of the construction cross passage grid steel frame 3 in the support of the construction cross passage and the main tunnel connection section is welded at the junction of the first steel pad 601 of the pre-supported and then broken steel gantry 6 and the arch wall. The innermost contour of the pre-supported and then broken steel gantry 6 is located on the contour line of the main tunnel entrance excavation face.

[0035] An opening door grid steel frame 7 is erected inside the first-support-then-break steel gantry 6, and an opening door steel frame 8 is erected inside the opening door grid steel frame 7.

[0036] The main tunnel support includes the main tunnel grid steel frame 9 and shotcrete structure and the main tunnel steel frame 10 and shotcrete structure. The main tunnel grid steel frame 9 and shotcrete structure are located on the side of the opening portal grid steel frame 7 facing the main tunnel. The main tunnel steel frame 10 and shotcrete structure are located on the side of the opening portal steel frame 8 facing the main tunnel and on the inner side below the main tunnel grid steel frame 7 and shotcrete structure. The main tunnel grid steel frame 9 and shotcrete structure are located along the main tunnel steel frame 10 and shotcrete structure facing the main tunnel.

[0037] The inner side of the main tunnel support structure is the main tunnel structure 12, and the inner side of the construction cross passage support is the construction cross passage secondary lining structure 11. The first-support-then-break steel gantry 6, the opening door grid steel frame 7, and the opening door steel frame 8 are all cast inside the construction cross passage secondary lining structure 11. The main tunnel structure 12 and the construction cross passage secondary lining structure 11 are equipped with a structural middle plate 13 that isolates the upper and lower spaces.

[0038] The main tunnel support arch foot and the first-support-then-break steel portal frame 6, the opening portal grid steel frame 7, and the opening portal steel frame 8 are all erected on the rock surface after the soil above the main tunnel has been excavated.

[0039] As a preferred option, the overall structure of the pre-supported and post-breaking steel gantry 6 is as follows: a second steel pad 603 is arranged inside the first steel pad 601, a first steel section 602 is welded between the first steel pad 601 and the second steel pad 603, a third steel pad 604 and a fourth steel pad 606 are arranged inside the second steel pad 603, a second steel section 605 is welded between the third steel pad 604 and the fourth steel pad 606, the second steel pad 603 and the third steel pad 604 are connected by bolts, and the outline of the fourth steel pad 606 is consistent with the outline of the main tunnel entrance excavation face. Figure 4 (a) and Figure 4 (b) is a schematic diagram of the steel gantry frame 6 with different viewpoints, showing the structure of the first-support-then-break type.

[0040] Preferably, the first steel section 602 and the second steel section 605 are double-jointed I25a steel sections. The first steel section 602 faces the longitudinal direction of the main tunnel and is evenly arranged circumferentially between the first steel pad 601 and the second steel pad 603. The second steel section 605 faces the direction perpendicular to the longitudinal direction of the main tunnel and is circumferentially welded to the third steel pad 604 and the fourth steel pad 606 along the outline of the first-support-then-break steel gantry 6.

[0041] As a preferred embodiment, the dimensions of the first steel pad 601 in the pre-supported and then broken steel gantry 6 are not less than 450mm (length) × 350mm (width) × 10mm (height), and the dimensions of the second steel pad 603, the third steel pad 604, and the fourth steel pad 606 are not less than 300mm (length) × 350mm (width) × 10mm (height).

[0042] As a preferred option, the height and inclination angle of the first steel section 602 in the pre-supported and then broken steel gantry frame 6 should be adjusted according to the actual site conditions.

[0043] As a preferred option, the second steel pad 603 and the third steel pad 604 in the pre-supported and then broken steel gantry frame 6 are connected by M27 bolts with a bolt length of 70mm and a steel plate opening of 30mm.

[0044] As a preferred option, the double-row small guide pipe 1 for the construction cross passage adopts... The advanced small guide tubes are not less than 4.5m in length. The outer insertion angle of the two rows of small guide tubes is adjusted according to the curvature of the arch, and the overlap length is not less than 2m.

[0045] As a preferred option, the anchor bolts 4 for the construction cross passage are made by installing two hollow anchor bolts in each cross passage grid steel frame 6, with the anchor bolt length not less than 6m.

[0046] As a preferred option, the main tunnel's advanced central pipe roof 5 adopts... For pipe sheds, the external insertion angle is 1 to 3 degrees.

[0047] As a preferred option, the number of main tunnel grid steel frames 9 erected at the tunnel excavation entrance is 3 to 4.

[0048] As a preferred option, steel plates are respectively installed on the contact surfaces between the opening door grille steel frame 7 and the opening door type steel frame 8, and between the main tunnel grille steel frame 9 and the main tunnel type steel frame 10, and the two contact surface steel plates are connected by bolts.

[0049] Preferably, longitudinal steel reinforcement is used to connect the portal steel frame 7 and the main tunnel steel frame 9, as well as the portal steel frame 8 and the main tunnel steel frame 10. The inner and outer sides of the steel reinforcement should be staggered.

[0050] The construction steps for the connection section structure between the construction cross passage and the main tunnel according to this utility model are as follows:

[0051] Step S1: Construction of the standard section of the cross passage, including advance support, support, and passage structure.

[0052] Step S2: Excavate the upper soil of the construction cross passage connecting to the main tunnel, so that the arch of the construction cross passage in the longitudinal direction presents the upward convex arc curve of the arch of the main tunnel.

[0053] Step S3 involves constructing the pre-support for the connection section between the construction cross passage and the main tunnel, including the double-row small guide pipes 1 at the top and the sidewall anchors 2.

[0054] Step S4: The support outline of the construction cross passage and the main tunnel connection section adopts an arched straight sidewall design on the side close to the main tunnel. The cross passage grid steel frame 3 for the support of the construction cross passage and the main tunnel connection section is arranged along the arch. On the excavation side of the main tunnel, the outermost first steel pad 601 of the first-support-then-break steel gantry 6 is welded to the main reinforcement of the arched cross passage grid steel frame 3 adjacent to the sidewall. The support of the construction cross passage and the main tunnel connection section is poured with shotcrete.

[0055] Step S5: After the shotcrete supporting the connection section between the construction cross passage and the main tunnel reaches the required strength, install the construction cross passage anchor bolts 4 at the position of the construction cross passage grid steel frame 3 in the support of the connection section between the construction cross passage and the main tunnel along the outline of the main tunnel excavation face. Then, install the main tunnel advance pipe shed 5 above the outline of the main tunnel excavation face.

[0056] Step S6: Weld the main structure of the pre-supported and then broken steel gantry 6 to the first steel pad 601 inside the support of the cross passage connecting the main tunnel and the main tunnel on the side close to the main tunnel.

[0057] Step S7: Remove the support structure and sidewall anchor rods 2 of the construction cross passage connecting the main tunnel and the main tunnel within the construction area of ​​the main tunnel side, and weld the cut-off construction cross passage grid steel frame 3 to the construction cross passage locking foot anchor rod 4.

[0058] Step S8: Excavate the soil above the main tunnel, erect the main tunnel grid steel frame 9 within a certain range at the entrance of the main tunnel, and spray concrete for pouring.

[0059] Step S9: Erect the main tunnel steel frame 10 inside the cast main tunnel grid steel frame 9 and spray concrete for pouring.

[0060] Step S10: Install the opening portal steel frame 7 at the corresponding position of the projection of the main tunnel grid steel frame 9 inside the first-support-then-break steel gantry 6, and install the opening portal steel frame 8 at the corresponding position of the projection of the main tunnel steel frame 10 inside the portal steel frame.

[0061] Step S11: Continue to excavate the soil above the main tunnel, and continue to erect the main tunnel grid steel frame 9 along the main tunnel steel frame 10 spray concrete structure and pour the spray concrete.

[0062] Step S12: Excavate the lower soil of the cross passage connecting to the main tunnel and the lower soil of the main tunnel.

[0063] Step S13: Construct the main tunnel structure 12 and the secondary lining structure 11 of the cross passage.

[0064] Step S14: Construct the structural plate 13 and other internal structures.

[0065] The present invention has been described in detail above through embodiments, but the content described is only an exemplary embodiment of the present invention and should not be considered as limiting the scope of implementation of the present invention. The protection scope of the present invention is defined by the claims. Any technical solutions designed by those skilled in the art using the technical solutions described in the present invention, or designed by those skilled in the art under the inspiration of the technical solutions of the present invention, within the substance and protection scope of the present invention, to achieve the above-mentioned technical effects, or equivalent changes and improvements made to the scope of the application, should still fall within the patent protection scope of the present invention. It should be noted that, for clarity, descriptions of some components and processes that are not directly and obviously related to the protection scope of the present invention but are known to those skilled in the art have been omitted in the description of the present invention.

Claims

1. A hyperbolic arch-shaped tunneling structure for soft strata, characterized by pre-support and post-breakage excavation, wherein... This includes the excavation of the construction cross passage connecting the standard section of the construction cross passage and the main tunnel, and the construction cross passage arch of the construction cross passage connecting the main tunnel has an upward convex arc curve in the longitudinal direction, forming a hyperbolic arch structure in both the horizontal and vertical directions. The advanced support for the connection section between the construction cross passage and the main tunnel includes double rows of small guide pipes at the top and sidewall anchors; The support for the connection between the construction cross passage and the main tunnel includes the construction cross passage grid steel frame and shotcrete structure. The support outline of the connection between the construction cross passage and the main tunnel adopts an arched top and straight sidewall design on the side closer to the main tunnel. The construction cross passage grid steel frame of the support for the connection between the construction cross passage and the main tunnel is arranged along the hyperbolic arched top. In the support of the connection section between the construction cross passage and the main tunnel, the construction cross passage grid steel frame is equipped with a construction cross passage locking anchor at the cross section position on the outline of the main tunnel entrance excavation face. One end of the construction cross passage locking anchor is welded to the cross section of the cross passage grid steel frame. The main tunnel entrance is equipped with a main tunnel advanced middle pipe shed, which is located above the main tunnel support at the entrance position. A first-support-then-break steel gantry is installed inside the support of the construction cross passage and the main tunnel connection section near the main tunnel. The main reinforcement of the construction cross passage grid steel frame in the support of the construction cross passage and the main tunnel connection section is welded at the junction of the first steel pad plate of the first-support-then-break steel gantry and the arch wall. The innermost outline of the first-support-then-break steel gantry is located on the outline line of the main tunnel entrance excavation face. An opening-type steel frame is installed inside the pre-supported and then broken steel gantry frame, and an opening-type steel frame is installed inside the opening-type steel frame. The main tunnel support includes the main tunnel grid steel frame and shotcrete structure and the main tunnel steel frame and shotcrete structure. The main tunnel grid steel frame and shotcrete structure is located on the side of the opening portal grid steel frame facing the main tunnel. The main tunnel steel frame and shotcrete structure is located on the side of the opening portal steel frame facing the main tunnel and is located on the inner side below the main tunnel grid steel frame and shotcrete structure. The main tunnel grid steel frame and shotcrete structure is located along the main tunnel steel frame and shotcrete structure facing the main tunnel. The inner side of the main tunnel support structure is the main tunnel structure, and the inner side of the construction cross passage support is the construction cross passage secondary lining structure. The first-support-then-break steel portal frame, the opening door grid steel frame, and the opening door steel frame are all cast inside the construction cross passage secondary lining structure. The main tunnel structure and the construction cross passage secondary lining structure are equipped with a structural middle plate that isolates the upper and lower spaces. The main tunnel support arch foot, the pre-support and post-break steel portal frame, the opening portal grid steel frame, and the opening portal steel frame are all erected on the rock surface after the soil above the main tunnel has been excavated.

2. The hyperbolic arch-shaped tunneling structure for soft strata according to claim 1, characterized in that, The overall structure of the pre-supported and then broken steel gantry is as follows: a second steel pad is arranged inside the first steel pad, a first type of steel is welded between the first steel pad and the second steel pad, a third steel pad and a fourth steel pad are arranged inside the second steel pad, a second type of steel is welded between the third steel pad and the fourth steel pad, and the second steel pad and the third steel pad are connected by bolts.

3. The hyperbolic arch-shaped tunneling structure for soft strata according to claim 2, characterized in that, The first and second steel sections are double-jointed I25a steel sections. The first steel section faces the longitudinal direction of the main tunnel and is evenly arranged circumferentially between the first and second steel pads. The second steel section faces perpendicular to the longitudinal direction of the main tunnel and is welded circumferentially to the third and fourth steel pads along the outline of the first-support-then-break steel gantry.

4. The hyperbolic arch-shaped tunneling structure for soft strata according to claim 1, characterized in that, Double-row small guide pipes are used in the construction cross passage. The advanced small guide tubes are not less than 4.5m in length. The outer insertion angle of the two rows of small guide tubes is adjusted according to the curvature of the arch, and the overlap length is not less than 2m.

5. The hyperbolic arch-shaped tunneling structure for soft strata according to claim 1, characterized in that, For the construction cross passage anchor bolts, two hollow anchor bolts are installed in each cross passage grid steel frame, with an anchor bolt length of not less than 6m.

6. The hyperbolic arch-shaped tunneling structure for soft strata according to claim 1, characterized in that, The main tunnel adopts advanced central pipe roof. For pipe sheds, the external insertion angle is 1 to 3 degrees.

7. The hyperbolic arch-shaped tunneling structure for soft strata according to claim 1, characterized in that, The number of main tunnel grid steel frames erected at the tunnel excavation entrance is 3 to 4.

8. The hyperbolic arch-shaped tunneling structure for soft strata according to claim 1, characterized in that, Steel plates are installed at the joint surfaces between the steel frame of the opening portal grille and the steel frame of the opening portal, and between the steel frame of the main tunnel grille and the steel frame of the main tunnel. The steel plates at the two joint surfaces are connected by bolts.

9. The hyperbolic arch-shaped tunneling structure for soft strata according to claim 1, characterized in that, The steel frame of the opening portal grille is longitudinally connected to the steel frame of the main tunnel grille, and the steel frame of the opening portal is longitudinally connected to the steel frame of the main tunnel. The steel bars should be arranged alternately on the inside and outside.

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