Construction method for converting inclined shaft into main tunnel
By gradually raising the elevation of the inclined shaft arch, setting up reinforcing rings, and using scaffolding, the problem of uneven stress on the support structure during the construction of the inclined shaft turning tunnel was solved, thus improving the stability and safety of the construction.
Patent Information
- Application Number
- CN202511427788.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-30
- Publication Date
- 2025-11-07
AI Technical Summary
In the traditional method of constructing a main tunnel from an inclined shaft, the support structure is subjected to unreasonable stress, resulting in uneven and unstable stress at the intersection of the inclined shaft and the main tunnel, which affects construction safety.
The construction method employed was to gradually raise the elevation of the inclined shaft arch and extend the steel frame, install reinforcing rings, strengthen the joints at the junction of the inclined shaft and the main tunnel, use scaffolding as a temporary protective structure, and construct the shaft by first supporting and then excavating, in order to ensure the stability of the surrounding rock.
This effectively avoids stress concentration, improves the overall strength and construction safety of the junction, reduces the risk of surrounding rock collapse, and enhances the stability and safety of construction.
Smart Images
Figure CN120906569A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of tunnel construction, in particular to a construction method for converting a inclined shaft into a vertical shaft. BACKGROUND
[0002] In the field of tunnels and underground engineering, inclined shafts, as an important channel connecting the ground and the main tunnel, are widely used in water conservancy, transportation, mining and other engineering, and bear key functions such as construction ventilation, drainage, transportation and post-operation maintenance. The construction of the inclined shaft into the vertical shaft is a key conversion link of the whole project, and its construction quality and efficiency directly affect the safety, economy and overall progress of the subsequent main tunnel construction.
[0003] At present, the existing inclined shaft conversion into vertical shaft construction technology mostly adopts step-by-step excavation method, such as first excavating the pilot tunnel and then expanding the main tunnel, or using reserved core soil, bench method and other ways to control the deformation of surrounding rock. However, the traditional construction method often has unreasonable stress of supporting structure, which easily leads to uneven stress and instability of the intersection section of inclined shaft and main tunnel, affecting the construction safety. SUMMARY The purpose of the present application is to solve the problem of the traditional construction method in the background art, which often has unreasonable stress of supporting structure, easily leading to uneven stress and instability of the intersection section of inclined shaft and main tunnel, affecting the construction safety. The present application provides a construction method for converting an inclined shaft into a vertical shaft.
[0004] The present application provides a construction method for converting an inclined shaft into a vertical shaft, comprising the following steps: S1: when the inclined shaft approaches the intersection mileage of the vertical shaft, gradually raise the vault elevation of the inclined shaft, and lengthen the steel frame; S2: after the inclined shaft is excavated to the outline of the vertical shaft, a reinforcing ring is arranged at the intersection of the inclined shaft and the vertical shaft; S3: from the intersection of the vertical shaft and the inclined shaft, a shed frame is used to enter the vertical shaft, and the vertical shaft excavation of the intersection section is carried out; S4: then the initial support of the vertical shaft upper bench is constructed in the shed frame, and then the cross section excavation of the vertical shaft is carried out on both sides.
[0005] The construction method of the present application gradually raises the elevation of the inclined shaft arch top and lengthens the steel frame, effectively avoiding stress concentration at the junction of the inclined shaft and the main tunnel due to sudden elevation change, while ensuring the continuity of the inclined shaft support structure, then a reinforcing ring is arranged at the junction, the reinforcing ring is used to reinforce the node at the junction of the inclined shaft and the main tunnel, improve the overall strength of the junction, solve the problem that the traditional method cannot guarantee the stability of the junction, then the shed frame enters the main tunnel and excavates the intersection section, the shed frame as a temporary protective structure can reduce the exposure time of the surrounding rock during the excavation of the main tunnel, avoid the collapse of the surrounding rock due to stress release, then the initial support of the main tunnel upper step is constructed in the shed frame and then excavated to both sides, realizing first support and then excavation, restraining the deformation of the surrounding rock in advance, avoiding the instability of the intersection section due to lagging support in traditional construction, and effectively improving the construction safety Preferably, in S2, the reinforcing ring comprises a portal steel frame and an inclined shaft steel frame, the inclined shaft steel frame is located inside the portal steel frame, and the portal steel frame is connected with the inclined shaft steel frame.
[0006] The nested connection structure of the portal steel frame and the inclined shaft steel frame forms an inner and outer two-layer bearing system for the reinforcing ring, avoiding the instability problem of the traditional single steel frame reinforcing ring, and providing stable support for subsequent main tunnel excavation.
[0007] Preferably, the portal steel frame comprises a crossbeam and a column, the crossbeam is located above the inclined shaft steel frame, the column is located on both sides of the inclined shaft steel frame (32, and the crossbeam and the inclined shaft steel frame are connected by diagonal braces. A plurality of anchor rods are arranged on the column.
[0008] The diagonal braces are arranged between the crossbeam and the inclined shaft steel frame to connect them, so that the portal steel frame and the inclined shaft steel frame form a rigid whole, avoiding stress disconnection, so as to uniformly transmit the stress of the intersection section to the entire reinforcing ring and improve the structure's anti-deformation ability Preferably, in S3, the shed frame is excavated obliquely upward to the center line of the main tunnel and reaches the arch top elevation of the main tunnel, and then excavated forward to the arch foot position of the upper step on the outside of the main tunnel.
[0009] The shed frame is excavated obliquely upward to the center line of the main tunnel and reaches the arch top elevation of the main tunnel, so as to ensure that the top of the shed frame can cover the stress area of the main tunnel arch top, provide targeted protection for the main tunnel arch top excavation, and avoid the collapse of the main tunnel arch top; Further, the shed frame is excavated to the arch foot position of the upper step on the outside of the main tunnel, so that the shed frame extends to the arch foot position of the upper step of the main tunnel and covers the entire excavation section of the upper step of the main tunnel, so as to provide comprehensive protection for the surrounding rock during subsequent main tunnel excavation, solve the problem of insufficient protection range of the traditional shed frame, and provide a stable working space for the initial support of the upper step.
[0010] Preferably, the arch top elevation of the shed frame exceeds the designed excavation line of the main tunnel.
[0011] By reserving a compensation area for construction error through the vault elevation of the shed frame exceeding the designed excavation line of the main tunnel, even if there is a deviation in the installation of the steel frame or slight settlement of the surrounding rock, the shed frame can still ensure that it completely covers the vault of the main tunnel.
[0012] Preferably, after the shed frame is completed, concrete is sprayed inside the shed frame.
[0013] Preferably, in S4, the initial support of the main tunnel and the upper arc-shaped pilot tunnel are constructed along the direction of the main tunnel.
[0014] Preferably, in S4, after the excavation of the intersection section of the main tunnel is completed, the construction of the inverted arch and the secondary lining of the main tunnel is carried out in a timely manner, and the initial support of the main tunnel is connected with the inverted arch of the main tunnel to form a ring.
[0015] Preferably, in S1: according to the height difference between the inclined shaft and the main tunnel, the starting mileage of the vault expansion of the inclined shaft is determined, and the elevation of the vault of the inclined shaft is controlled within 30%.
[0016] Preferably, when the inclined shaft intersects with the main tunnel at an acute angle, a trumpet section is arranged near the acute angle of the main tunnel close to the inclined shaft.
[0017] The trumpet section on the main tunnel enlarges the cross section of the intersection section of the main tunnel, disperses the stress originally concentrated at the acute angle of the main tunnel to a larger range of surrounding rock and support structure, reduces the local stress peak value, and avoids deformation or cracking of the support of the main tunnel due to overload; at the same time, the trumpet section enables the support structures of the main tunnel and the inclined shaft to smoothly overlap, solves the uneven stress problem caused by the connection breakpoint of the traditional reinforcement, and enhances the overall strength of the intersection section of the inclined shaft.
[0018] Compared with the prior art, the present application has the following beneficial effects: The construction method of the present application for converting the inclined shaft into the main tunnel gradually raises the vault elevation of the inclined shaft and extends the steel frame, effectively avoiding stress concentration at the junction of the inclined shaft and the main tunnel due to sudden change in elevation, while ensuring the continuity of the support structure of the inclined shaft, then a reinforcing ring is arranged at the junction to reinforce the node at the junction of the inclined shaft and the main tunnel, thereby improving the overall strength of the junction, solving the problem that the traditional method cannot guarantee the stability of the junction, and then a shed frame is used to enter the main tunnel and excavate the intersection section, the shed frame as a temporary protective structure can reduce the exposure time of the surrounding rock during excavation of the main tunnel, thereby avoiding collapse of the surrounding rock due to stress release, then the initial support of the upper step of the main tunnel is constructed inside the shed frame and excavated to both sides, realizing first support and then excavation, thereby restraining deformation of the surrounding rock in advance, avoiding the problem of instability of the intersection section caused by lagging support in traditional construction, and effectively improving the safety of construction. BRIEF DESCRIPTION OF DRAWINGS
[0019] Figure 1 is a plan view of the conversion of the inclined shaft into the main tunnel.
[0020] Figure 2 is a long schematic view of the intersection of the inclined shaft and the vertical shaft.
[0021] Figure 3 is a schematic view of the structure of the reinforcing ring.
[0022] Figure 4 is a schematic view of the construction of the inclined shaft into the vertical shaft (step one).
[0023] Figure 5 is a schematic view of the construction of the inclined shaft into the vertical shaft (step two).
[0024] Figure 6 is a schematic view of the construction of the inclined shaft into the vertical shaft (step three).
[0025] Figure 7 is a schematic view of the construction of the inclined shaft into the vertical shaft (step four).
[0026] Figure 8 is a schematic view of the construction of the inclined shaft into the vertical shaft (step five).
[0027] Marked in the figure 1 - inclined shaft, 2 - vertical shaft, 3 - reinforcing ring, 31 - portal steel frame, 311 - crossbeam, 312 - column, 32 - inclined shaft steel frame, 33 - inclined strut, 4 - small guide pipe, 5 - inclined shaft section lining, 6 - shed frame, 7 - trumpet, 8 - reinforcing steel frame, 9 - vertical shaft inverted arch steel frame, 10 - upper step initial support 20 - arc-shaped guide pit 30 - inclined shaft support steel frame. DETAILED DESCRIPTION
[0028] The application will be described in further detail below with specific embodiments. However, this should not be understood as limiting the above-mentioned subject matter of the application to only the following embodiments, and any technology realized based on the content of the application falls within the scope of the application.
[0029] In the description of specific embodiments of the present application, the orientation or positional relationship of the terms such as "up", "down", "left", "right", "center", "inner", "outer" and the like are expressed based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship of the product / device / apparatus of the present application when it is usually used. These orientation or positional relationship terms are only for the convenience of describing the present application or simplifying the description in specific embodiments, so as to facilitate the quick understanding of the scheme by the technicians, and therefore cannot be understood as indicating or implying that a specific device / component / element must have a specific orientation or be constructed and operated in a specific positional relationship, and therefore cannot be understood as a limitation on the present application.
[0030] In addition, the terms "horizontal", "vertical", "suspension", "parallel", "coaxial" and the like do not mean that the corresponding device / component / element must be absolutely horizontal or vertical or suspended or parallel or coaxial, but can be slightly inclined or deviated, as long as it does not affect the normal function of the related component. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined; "coaxial" means that two components are arranged as coaxial as possible, and are moved in a coaxial or approximately coaxial manner when the relative position changes. Alternatively, it can be simplified to understand that the corresponding device / component / element is arranged in the "horizontal", "vertical", "suspension", "parallel", "coaxial" direction, and can have an error / bias of ±10% relative to the corresponding direction, more preferably an error / bias of ±8% or less, more preferably an error / bias of ±6% or less, more preferably an error / bias of ±5% or less, and more preferably an error / bias of ±4% or less. For example, the deviation in the "coaxial" direction is controlled within 0.2-1mm, preferably within 0.2-0.5mm. As long as the corresponding device / component / element is within the error / bias range, it can still achieve its role in the present application scheme.
[0031] In addition, the terms "first", "second", "third" and the like in the description of the embodiments of the present application are only used to distinguish the same or similar components, and should not be understood as emphasizing or implying the relative importance of the specific components.
[0032] In addition, in the description of the embodiments of the present application, "several", "a plurality of", "several" represent at least 2. It can be 2, 3, 4, 5, 6, 7, 8, 9, etc. in any case, and even more than 9.
[0033] Furthermore, in the description of the technical solutions of the present application, unless otherwise explicitly specified / limited / limited, the terms "provided", "installed", "connected", "connected", "provided", "laid", "arranged" appearing in the description should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected, which can be welding, riveting, bolting, screwing and other commonly used connection means in the art. The connection can be mechanical connection, electrical connection or communication connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication between two elements.
[0034] Embodiment 1 The intersection section of the inclined shaft 1 and the main tunnel 2 is a key safety link of tunnel construction and a difficult point of tunnel construction, such as Figures 1-8 The embodiment discloses a construction method for changing an inclined shaft into a main tunnel, which is used for tunnel construction and comprises the following steps: S1: As shown in Figure 4 When the inclined shaft 1 approaches the intersection mileage of the main tunnel 2, the crown elevation of the inclined shaft 1 is gradually raised. By gradually raising the crown elevation of the inclined shaft 1, smooth transition of the crown of the inclined shaft 1 and the crown of the main tunnel 2 is realized, and local stress concentration of the tunnel caused by sudden change of the crown elevation is avoided. The crown expansion starting mileage of the inclined shaft 1 is determined according to the height difference between the inclined shaft 1 and the main tunnel 2, and the crown raising slope of the inclined shaft 1 is controlled to be within 30%.
[0035] The crown raising slope of the inclined shaft 1 is controlled to be within 30% to limit the crown elevation of the inclined shaft 1, so as to avoid rapid change of the crown elevation of the inclined shaft 1, which causes stress concentration and triggers surrounding rock collapse, and also reduces the difficulty of excavation.
[0036] Further, in the process of gradually raising the crown elevation of the inclined shaft 1, the support steel frame 30 in the inclined shaft 1 is gradually lengthened, as shown in Figure 1 ; S2: As shown in Figure 5 After the inclined shaft 1 is excavated to the contour line of the main tunnel 2, a reinforcing ring 3 is arranged at the intersection of the inclined shaft 1 and the main tunnel 2. The reinforcing ring 3 is used to reinforce the node at the intersection of the inclined shaft 1 and the main tunnel 2, so as to improve the overall strength of the intersection and solve the problem that the stability of the intersection section cannot be guaranteed by the traditional method.
[0037] In S2, as shown in Figure 3 The reinforcing ring 3 comprises a door-shaped steel frame 31 and an inclined shaft steel frame 32, the inclined shaft steel frame 32 is located inside the door-shaped steel frame 31, and the door-shaped steel frame 31 is connected with the inclined shaft steel frame 32.
[0038] Through the nested connection structure of the portal steel frame 31 and the inclined shaft steel frame 32, the reinforcing ring 3 forms an inner and outer two-layer bearing system, avoids the problem of instability of the traditional single steel frame reinforcing ring 3, and provides stable support for subsequent excavation of the main tunnel 2.
[0039] Specifically, the portal steel frame 31 includes a cross beam 311 and a column 312, the cross beam 311 is located above the inclined shaft steel frame 32, and the column 312 is located on both sides of the inclined shaft steel frame 32, and the cross beam 311 and the inclined shaft steel frame 32 are connected by a diagonal brace 33. The column 312 is provided with a plurality of anchor rods.
[0040] The cross beam 311 and the inclined shaft steel frame 32 are connected by the diagonal brace 33, so that the portal steel frame 31 and the inclined shaft steel frame 32 form a rigid whole, avoiding stress disconnection, so as to uniformly transmit the stress of the intersection section to the whole reinforcing ring and improve the structural anti-deformation capability.
[0041] Specifically, the reinforcing ring 3 is arranged at the intersection of the inclined shaft 1 and the main tunnel 2, the thickness of the reinforcing ring is selected according to design requirements, the reinforcing ring 3 includes a portal steel frame 31 and an inclined shaft steel frame 32, the inclined shaft steel frame 32 is located in the portal steel frame 31, the portal steel frame 31 and the inclined shaft steel frame 32 are welded together, adjacent steel frames are connected by longitudinal steel bars, and the interval is 1 m. The portal steel frame 31 is composed of a cross beam 311 and a column 312, a gap between the cross beam 311 and the inclined shaft steel frame 32 is symmetrically welded with a diagonal brace 33, and the gap is backfilled and compacted by spraying concrete after the steel frame is installed. The cross beam 311 of the portal steel frame 31 serves as an arch support point of the main tunnel 2, and the column 312 of the portal steel frame 31 is provided with a locking foot anchor pipe and an anchor rod.
[0042] In an optional embodiment, near the main tunnel 2, the main tunnel inverted arch steel frame 9 is welded with the outermost side of the reinforcing ring 3 of the inclined shaft 2, and the main tunnel 2 inverted arch lining steel bar is connected with the pre-buried steel bar in the lining of the inclined shaft 1, so as to ensure the close connection of the intersection of the main tunnel 2 and the inclined shaft 1, and to bear force together.
[0043] In S2, as shown in Figure 2 , a forward support is applied at the intersection of the inclined shaft 1 and the main tunnel 2, and the overage support adopts a small guide pipe 4 with a diameter of 42, a length of 4 meters, and a longitudinal interval of 3 meters, which is arranged along the vault of the main tunnel 2.
[0044] In an optional embodiment, as shown in Figure 2 , after the construction of the reinforcing ring 3, the lining 5 of the intersection section of the inclined shaft is applied in time.
[0045] In S2, the reinforcing ring 3 at the intersection of the inclined shaft 1 must be deep into the initial support section of the main tunnel 2, so as to provide strong support for the support of the main tunnel 2.
[0046] S3: As shown in the figure, from the intersection of the vertical shaft 2 and the inclined shaft 1, the shed frame 6 enters the vertical shaft 2, and the intersection section of the vertical shaft 2 is excavated; Figure 6 The shed frame 6 forms a shed hole in the area to be excavated in the vertical shaft 2, that is, the shed hole enters the vertical shaft 2, and the shed frame 6 is used as a temporary bearing structure to avoid direct exposure of the surrounding rock during excavation of the intersection section of the vertical shaft 2, to cycle the construction time, effectively control the deformation of the surrounding rock, and solve the collapse risk caused by the lagging support of the traditional method.
[0047] In S3, the shed frame 6 is excavated obliquely upward to the center line of the vertical shaft 2 and reaches the vault elevation of the vertical shaft 2, and then excavates forward to the upper step spring position on the outside of the vertical shaft 2, and the shed frame 6 timely follows up; By obliquely climbing the shed frame 6 to the center line of the vertical shaft 2 and reaching the vault elevation of the vertical shaft 2, it is ensured that the top of the shed frame 6 can cover the stress area of the vertical shaft 2 vault, and the vertical shaft 2 vault is protected for excavation, avoiding the collapse of the vertical shaft 2 vault; Further, excavate to the upper step spring position on the outside of the vertical shaft 2 to extend the shed frame 6 to the upper step spring position of the vertical shaft 2, and cover the entire excavation section of the upper step of the vertical shaft 2, so that the surrounding rock can be fully protected during subsequent excavation of the vertical shaft 2, solving the problem of insufficient protection range of the traditional shed frame, and providing a stable working space for the initial support of the upper step.
[0048] Among them, the vault elevation of the shed frame 6 exceeds the design excavation line of the vertical shaft 2.
[0049] By the vault elevation of the shed frame 6 exceeding the design excavation line of the vertical shaft 2, a compensation area for construction error is reserved, so that even if there is a deviation in the installation of the steel frame or a slight settlement of the surrounding rock, the shed frame 6 can still completely cover the vertical shaft 2 vault, avoiding the gap caused by insufficient protection.
[0050] Among them, after the shed frame 6 is completed, the inside of the shed frame 6 is sprayed with concrete.
[0051] Spraying concrete inside the shed frame 6 forms a composite support structure with the shed frame 6, improving the overall bearing capacity of the shed frame 6, and avoiding deformation caused by overload of a single steel frame; Further, the gap between the shed frame 6 and the surrounding rock is filled with sprayed concrete to prevent surrounding rock fragments from falling and ensure the safety of workers, while enhancing the synergy between the shed frame 6 and the surrounding rock and further restraining the deformation of the surrounding rock.
[0052] Among them, the shed frame 6 includes a plurality of steel frames, and an anchor pipe is arranged at the spring of each steel frame.
[0053] The arch spring of the shed frame 6 is anchored to the deep layer of the surrounding rock through the anchor pipe to limit the sliding and sinking of the arch spring under lateral force, ensuring the overall stability of the shed frame; The anchor pipe evenly transmits the load of the shed frame 6 to the surrounding rock, avoids local stress concentration at the arch foot, further improves the anti-deformation ability of the shed frame 6, and provides continuous and stable protection for subsequent excavation of the main tunnel 2.
[0054] Specifically, the shed frame 6 adopts I16 type steel, and the interval is 1 m. Two φ42 lock foot anchor pipes are arranged at the arch foot of each shed frame 6.
[0055] S4: as shown in Figure 7 , Figure 8 , then the upper step initial support 10 of the main tunnel 2 is constructed in the shed frame 6, and then the cross section of the main tunnel 2 is excavated to both sides; Among them, along the direction of the main tunnel 2, the upper step initial support 10 is constructed and the upper arc-shaped guide pit 20 is completed. The scheme of supporting first and then excavating is adopted, and under the protection of the shed frame 6, the upper step initial support 10 of the main tunnel 2 is constructed.
[0056] At the same time, the completed upper arc-shaped guide pit 20 and the upper step initial support 10 jointly play a temporary supporting role for the upper step of the main tunnel 2.
[0057] Specifically, along the direction of the main tunnel 2, the temporary support on one side of the shed frame 6 is removed, the upper step initial support 10 of the main tunnel 2 is constructed and the upper arc-shaped guide pit 20 is excavated according to the geological conditions and reasonable excavation method and support parameters, after 10 m of forward excavation, the concrete is sprayed to close the working face, and the excavation in this direction is temporarily stopped; The temporary support on the other side of the shed frame 6 is removed, the upper step initial support 10 of the main tunnel 2 is constructed and the upper arc-shaped guide pit 20 is excavated according to the geological conditions and reasonable excavation method and support parameters, after 10 m of forward excavation, the concrete is sprayed to close the working face, and the excavation in this direction is temporarily stopped.
[0058] After the excavation of the intersection section of the main tunnel 2 is completed, the construction of the inverted arch and the secondary lining of the main tunnel 2 is timely performed, and the upper step initial support 10 of the main tunnel 2 is connected with the inverted arch of the main tunnel 2 to form a ring.
[0059] The inverted arch is timely constructed and connected with the upper step initial support to form a ring, so that the initial support of the main tunnel 2 forms a complete closed structure, and the overall bearing capacity of the support system of the main tunnel 2 is greatly improved; Further, the long-term stability of the intersection section is enhanced, and the secondary deformation of the surrounding rock in the later operation process is resisted.
[0060] In an optional embodiment, during the intersection of the inclined shaft 1 and the main tunnel 2, the acute angle intersection of the inclined shaft 1 and the main tunnel 2 is prone to occur, as shown in Figure 1When the inclined shaft 1 intersects with the tunnel at an acute angle, the intersection section will form a force concentration area, and the acute angle side of the main tunnel 2 needs to bear the superimposed action of the vertical load of the inclined shaft 1 and the horizontal thrust of the main tunnel 2, which is easy to cause the lining of the main tunnel 2 to crack and the steel frame to deform, at the same time, the support structures of the main tunnel 2 and the inclined shaft 1 are difficult to smoothly connect at the acute angle, which is easy to form a support breaking point, further aggravates the uneven stress, and affects the overall stability of the intersection section; In order to solve the construction problems caused by the acute angle intersection, a trumpet part 7 is arranged at the acute angle intersection between the inclined shaft 1 and the main tunnel 2, which is close to the inclined shaft 1, and the cross-sectional size of the main tunnel 2 at the intersection is expanded through the trumpet part 7, especially the excavation is extended at the acute angle side, so that the stress originally concentrated at the acute angle of the main tunnel is dispersed to the surrounding rock and the support structure in a larger range.
[0061] Specifically, after the inclined shaft 1 is connected to the main tunnel 2, a reinforcing steel frame 8 is arranged at the acute angle intersection between the inclined shaft 1 and the main tunnel 2, one end of the reinforcing steel frame 8 is connected to the support steel frame of the inclined shaft 1, the other end is connected to the support steel frame of the main tunnel 2, and the reinforcing steel frame 8 is located outside the acute angle of the inclined shaft 1 and the main tunnel 2. Before pouring the second lining of the main tunnel 2, the reinforcing steel frame 8 is poured with concrete to form the trumpet part 7, and then the second lining of the main tunnel 2 is poured.
[0062] The inclined shaft support steel frame 30 is partially located in the trumpet part 7.
[0063] The trumpet part 7 on the main tunnel 2 expands the cross-sectional area of the intersection section of the main tunnel 2, disperses the stress originally concentrated at the acute angle of the main tunnel 2 to the surrounding rock and the support structure in a larger range, reduces the local stress peak value, avoids the deformation or cracking of the support of the main tunnel 2 due to overload, and at the same time, the trumpet part 7 enables the support structures (such as steel frames) of the main tunnel 2 and the inclined shaft 1 to be smoothly connected, solves the uneven stress problem caused by the connection breakpoint of the traditional reinforcing steel, and enhances the overall strength of the intersection section of the inclined shaft 1.
[0064] The above only describes the preferred embodiments of the present application, and is not used to limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.
Claims
1. A method of constructing a vertical shaft into a horizontal tunnel, characterized by, The method comprises the following steps: S1: when the inclined shaft (1) approaches the intersection mileage of the main tunnel (2), gradually raise the vault elevation of the inclined shaft (1), and lengthen the steel frame; S2: after the inclined shaft (1) is excavated to the contour line of the main tunnel (2), a reinforcing ring (3) is arranged at the intersection of the inclined shaft (1) and the main tunnel (2); S3: from the intersection of the main tunnel (2) and the inclined shaft (1), a shed frame (6) is used to enter the main tunnel (2), and the intersection section of the main tunnel (2) is excavated; S4: then, the shed frame (6) is used to perform the initial support of the upper step of the main tunnel (2), and then the cross section of the main tunnel (2) is excavated to both sides.
2. The method of claim 1, wherein, In S2, the reinforcing ring (3) comprises a portal steel frame (31) and an inclined shaft steel frame (32), the inclined shaft steel frame (32) is located inside the portal steel frame (31), and the portal steel frame (31) is connected with the inclined shaft steel frame (32).
3. The method of claim 2, wherein, The portal steel frame (31) comprises a cross beam (311) and a stand column (312), the cross beam (311) is located above the inclined shaft steel frame (32), the stand column (312) is located on both sides of the inclined shaft steel frame (32), and the cross beam (311) and the inclined shaft steel frame (32) are connected with each other through a diagonal brace (33); A plurality of anchor rods are arranged on the stand column (312).
4. The method of claim 1, wherein, In S3, the shed frame (6) is obliquely excavated to the center line of the main tunnel (2) and reaches the vault elevation of the main tunnel (2), and then is excavated to the upper step arch foot position of the main tunnel (2) on the outside through a flat slope.
5. The method of claim 4, wherein, The vault elevation of the shed frame (6) exceeds the design excavation line of the main tunnel (2).
6. The method of claim 4, wherein, After the shed frame (6) is completed, the shed frame (6) is sprayed with concrete on the inside.
7. The method of claim 1, wherein, In S4, the initial support of the main tunnel (2) is performed along the direction of the main tunnel (2), and the upper arc-shaped pilot tunnel is completed.
8. The method of claim 1, wherein, In S4, after the intersection section of the main tunnel (2) is excavated, the inverted arch and the secondary lining of the main tunnel (2) are constructed in time, and the initial support of the main tunnel (2) is connected with the inverted arch of the main tunnel (2) to form a ring.
9. The method of claim 1, wherein, In S1: according to the height difference between the inclined shaft (1) and the main tunnel (2), the starting mileage of the vault expansion of the inclined shaft (1) is determined, and the vault elevation of the inclined shaft (1) is controlled to be within 30%.
10. The method of claim 1, wherein, When the inclined shaft (1) and the main tunnel (2) intersect at an acute angle, a horn part (7) is arranged at the acute angle of the main tunnel (2) close to the inclined shaft (1).