Off-wall drainage structure of arch wall and construction method of off-wall drainage structure

Abstract

The invention discloses an arch wall off-wall type drainage structure and a construction method thereof.The drainage structure comprises a water collecting gallery and a water passing channel, one end of the water collecting gallery communicates with a main tunnel, the other end of the water collecting gallery communicates with a drainage tunnel, and the water passing channel is located above a position from a right arch foot of a main tunnel line to a left side wall foot of the line and communicates with the water collecting gallery through a drainage pipe; and the water passing channel is communicated with the vault longitudinal water-rich karst pipeline through a plurality of water outlet points. According to the design, the water passing channel is arranged, the water passing channel is communicated with the water outlet point, water in the water-rich karst pipeline can flow into the water passing channel, meanwhile, the water collecting gallery is communicated between the main tunnel and the drainage tunnel, the water collecting gallery is communicated with the water passing channel through the drainage pipe, and the water in the water passing channel can be guided into the water collecting gallery and then is drained through the drainage tunnel; compared with the prior art, the water passing channel is arranged above the main tunnel and can be suitable for the working conditions that the water outlet point is located on the arch portion of the main tunnel and on the opposite side of the drainage tunnel and the water volume is large, meanwhile, water flow is drained from top to bottom, and drainage is smooth and stable.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel engineering construction, and in particular to an arch wall separated drainage structure and its construction method. Background Art

[0002] The lithology of the tunnel strata is mainly soluble rock. Due to the complex karst morphology, wide distribution area, large groundwater recharge area, and during tunnel construction, the tunnel body will pass through multiple fault fracture zones, lithological contact zones, and syncline structures, resulting in a high risk of water and mud inrush during the construction process, and making it difficult to drain groundwater after operation.

[0003] In order to ensure the safety of the tunnel lining structure, generally, a water discharge tunnel outside the main tunnel is set up to drain water. For example, a drainage structure and its construction method with a built-in water discharge tunnel disclosed in Chinese Patent CN116557059A drain groundwater through a drainage system (side ditch) by setting a sump, but this working condition is applicable to the situation where the water volume is not large. When the water volume is large, due to the limited drainage capacity of the side ditch, the accumulated water volume becomes larger and then overflows onto the roadbed, thus affecting the train operation. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects and problems of poor drainage effect in the main tunnel in the prior art, and provide an arch wall separated drainage structure with a better drainage effect and its construction method.

[0005] To achieve the above purpose, the technical solution of the present invention is: an arch wall separated drainage structure, including a water collection corridor and a water passing channel. One end of the water collection corridor is connected to the main tunnel, and the other end is connected to a water discharge tunnel. The water passing channel is located above the arch foot on the right side of the main tunnel line to the bottom of the side wall on the left side of the line. The water passing channel is connected to the water collection corridor through a drain pipe, and the water passing channel is connected to the longitudinal water-rich karst pipeline at the arch top through multiple water outlet points.

[0006] A gantry is connected to the inner side wall of the water collection corridor close to the main tunnel. A stop wall is arranged on the inner bottom wall of the water collection corridor close to the main tunnel. Concrete is filled between the left and right sides of the stop wall and the gantry, and a gap for water to pass through is arranged between the upper side of the stop wall and the gantry.

[0007] The stop wall is in a stepped shape, and an anti-erosion platform is connected between the wall foot of the stop wall and the inner bottom wall of the water collection corridor.

[0008] The gantry includes two spliced I-shaped steel frames. The I-shaped steel frames are in an inverted U shape, and the two side walls of the I-shaped steel frames pass through the inner bottom wall of the water collection corridor and are connected with concrete foundations.

[0009] A plurality of water collection drill holes are circumferentially arranged on the outer peripheral surface of the water collection corridor close to the main tunnel.

[0010] The water collection gallery is provided with a slope, the bottom wall of the water collection gallery is inclined, and a drainage side ditch is arranged on the lower side of the bottom wall of the water collection gallery.

[0011] The water passing channel is arc-shaped, an arch protection is arranged on the side close to the main tunnel of the water passing channel, concrete is filled between the arch protection and the portal frame, and a support is installed between the water passing channel and the surrounding rock.

[0012] The arch protection includes a plurality of first steel bars, second steel bars, third steel bars and fourth steel bars. The first steel bars and the second steel bars match the shape of the water passing channel. A plurality of the first steel bars are arranged along the length direction of the main tunnel, and a plurality of the second steel bars are arranged along the length direction of the main tunnel. The first steel bars are located outside the second steel bars. A plurality of the third steel bars are arranged at intervals along the length direction of the main tunnel and are respectively connected to the inner sides of the first steel bars and the outer sides of the second steel bars along the circumferential direction. Both ends of the fourth steel bar are hook-shaped, both ends of the fourth steel bar are connected to the third steel bars, and the first steel bars and the second steel bars are respectively located inside the hook parts of the fourth steel bar.

[0013] A construction method for an arch wall off-wall drainage structure, the construction method comprising the following steps:

[0014] Excavate the main tunnel, reveal the water outlet points of the arch part and the side walls, and observe the water volume of each water outlet point;

[0015] Widen and excavate the arch part of the main tunnel to form a water passing channel above the right arch foot to the left side wall foot of the main tunnel line. The water passing channel is communicated with all the water outlet points with large water output.

[0016] Excavate the water collection gallery, connect the two ends of the water collection gallery with the main tunnel and the water discharge tunnel respectively, and embed drainage pipes. The two ends of the drainage pipes are respectively communicated with the water collection gallery and the water passing channel.

[0017] When excavating the water collection gallery, install a portal frame on the inner side of the water collection gallery, and then build a stop wall at the place where the water collection gallery is close to the main tunnel. The stop wall and the portal frame are backfilled and compacted with concrete.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] 1. In an arch-wall separated drainage structure and its construction method of the present invention, by providing a water passage that communicates with the water outlet point, the water in the water-rich karst pipeline will flow into the water passage. At the same time, a water collection corridor is connected between the main tunnel and the drainage tunnel, and the water collection corridor is connected to the water passage through a drain pipe. In this way, the water in the water passage will be introduced into the water collection corridor and then discharged through the drainage tunnel. Compared with the prior art, setting the water passage above the main tunnel can be applicable to the working conditions where the water outlet point is located at the arch of the main tunnel, on the opposite side of the drainage tunnel, and with a large water volume. At the same time, the water flows out from top to bottom, and the drainage is smooth and stable. Therefore, the drainage effect of the present invention is better.

[0020] 2. In an arch-wall separated drainage structure and its construction method of the present invention, by providing a gantry, the stability of the water collection corridor can be improved. By providing a stop wall, the stop wall adopts a stepped design to disperse the pressure of the water flow, thereby improving the stability of the stop wall structure. By providing an anti-scour platform, the scour of the water flow can be avoided, thereby improving the stability of the stop wall. Therefore, the present invention has high reliability and good structural stability.

[0021] 3. In an arch-wall separated drainage structure and its construction method of the present invention, pressure relief is carried out by providing multiple water collection boreholes. The water collection corridor is provided with a slope to facilitate the rapid passage of water flow. At the same time, the bottom of the water collection corridor is inclined. After the sheet-like water is diverted from the arch crown of the main tunnel, it will flow down along this stop wall to the water collection corridor. When the water flow is large, it will cover the entire bottom and flow. When the water flow is small, it will flow into the drainage side ditch and flow along the drainage side ditch. In this way, the maintenance of the water collection corridor is convenient and the drainage is smooth, thereby ensuring the safe operation of the main tunnel. Therefore, the present invention has high reliability and good drainage effect.

[0022] 4. In an arch-wall separated drainage structure and its construction method of the present invention, the water passage adopts an arc design. When there is a water outlet point at the arch or side wall on the side of the main tunnel close to the drainage tunnel, the water flow will flow into the water collection corridor through the water pipeline and water collection boreholes under the action of gravity. When there is a water outlet point at the arch on the side of the main tunnel far from the drainage tunnel, the water flow will gather in the water passage. When the water flow overflows the midline and then flows downward into the drain pipe and is discharged. For the water outlet points at various positions, drainage and discharge can be carried out, and the applicable range is wide. By providing a protective arch, the stability of the water passage can be improved, and at the same time, the water flow can be prevented from flowing downward into the main tunnel from the water passage. Therefore, the present invention has high reliability and a wide applicable range. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of the present invention.

[0024] Figure 2 is Figure 1 an enlarged schematic diagram of part A in

[0025] Figure 3 It is a schematic cross - sectional view of the water - collecting corridor, main tunnel, and water - discharging tunnel in the present invention.

[0026] Figure 4 It is a schematic cross - sectional view of the water - collecting corridor and the stop - end wall in the present invention.

[0027] Figure 5 It is a schematic cross - sectional view of the water - collecting corridor and the anti - erosion platform in the present invention.

[0028] Figure 6 It is a schematic cross - sectional view of the water - passing pipeline in the present invention.

[0029] Figure 7 It is a schematic structural view of the protective arch in the present invention.

[0030] Figure 8 It is a schematic structural view of the first steel bar and the second steel bar in the present invention.

[0031] Figure 9 It is a partial schematic structural view of the first steel bar, the second steel bar, the third steel bar, and the fourth steel bar in the present invention.

[0032] Figure 10 It is a schematic cross - sectional view of the water - collecting corridor and the main tunnel in the present invention.

[0033] Figure 11 It is a schematic structural view of the gantry in the present invention.

[0034] In the figure: main tunnel 1, water - collecting corridor 2, water - passing channel 3, drain pipe 4, water outlet point 5, gantry 6, stop - end wall 7, concrete 8, gap 9, anti - erosion platform 10, I - shaped steel frame 11, concrete foundation 12, water - collecting borehole 13, drainage side ditch 14, protective arch 15, first steel bar 151, second steel bar 152, third steel bar 154, fourth steel bar 154, support 16, water - discharging tunnel 17. Detailed implementation manners

[0035] The present invention will be further described in detail below in combination with the accompanying drawings and specific implementation manners.

[0036] Example 1:

[0037] Refer to Figures 1 to 11 , an arch - wall separated - from - wall drainage structure, including a water - collecting corridor 2 and a water - passing channel 3. One end of the water - collecting corridor 2 is connected to the main tunnel 1, and the other end is connected to the water - discharging tunnel 17. The water - passing channel 3 is located above the arch foot on the right side of the main tunnel 1 line to the side - wall foot on the left side of the line. The water - passing channel 3 is connected to the water - collecting corridor 2 through a drain pipe 4, and the water - passing channel 3 is connected to the longitudinal water - rich karst pipeline at the arch top through a plurality of water outlet points 5;

[0038] The inner wall of the water collection gallery 2 close to the main tunnel 1 is connected to a portal frame 6, and the inner bottom wall of the water collection gallery 2 close to the main tunnel 1 is provided with a head wall 7. Concrete 8 is filled between the left and right sides of the head wall 7 and the portal frame 6. A gap 9 for water to pass through is provided between the upper side of the head wall 7 and the portal frame 6. The head wall 7 is step-shaped, and an anti-scouring platform 10 is connected between the foot of the head wall 7 and the inner bottom wall of the water collection gallery 2.

[0039] A construction method for an arch wall off-wall drainage structure, the construction method comprising the following steps:

[0040] Excavate the main tunnel 1, reveal the water outlet points 5 of the arch and the water outlet points 5 of the side wall, and observe the water volume of each water outlet point 5;

[0041] Expand the arch of the main tunnel 1, and form a water passage 3 from the arch foot on the right side of the main tunnel 1 line to the upper side of the side wall foot on the left side of the line. The water passage 3 is connected to all the water outlet points 5 with large water output;

[0042] A water collection gallery 2 is excavated so that both ends of the water collection gallery 2 are connected to the main tunnel 1 and the drainage tunnel 17 respectively, and a drainage pipe 4 is pre-buried in the surrounding rock, and both ends of the drainage pipe 4 are connected to the water collection gallery 2 and the water passage 3 respectively.

[0043] When excavating the water collection gallery 2, a portal frame 6 is installed on the inner side of the water collection gallery 2, and then a retaining wall 7 is set up near the main tunnel 1 of the excavated water collection gallery 2, and the space between the retaining wall 7 and the portal frame 6 is backfilled with concrete 8 to make it dense.

[0044] In this embodiment, the longitudinal water-rich karst pipeline on the arch is a water-rich karst pipeline naturally developed on the top of the main cave. The water collection gallery 2 adopts molded lining, the top width of the head wall 7 is 0.5m, and it is backfilled into a step shape to form a waterfall (the step is 50cm high and 20cm wide); an anti-scour platform 10 is arranged on the bottom plate of the water collection gallery 2 near the foot of the head wall 7, and the door frames 6 on both sides of the head wall 7 are backfilled with C20 concrete 8 for compaction.

[0045] Embodiment 2:

[0046] The basic content is the same as that of Example 1, except that:

[0047] See also Figure 5 , Figure 10 and Figure 11 The portal frame 6 includes two I-beam frames 11 spliced ​​to each other, and the I-beam frame 11 is in an inverted U shape. The two side walls of the I-beam frame 11 pass through the inner bottom wall of the water collection gallery 2 and are connected to a concrete foundation 12.

[0048] The water collection gallery 2 is provided with a plurality of water collection holes 13 along the circumferential direction on the outer peripheral surface close to the main tunnel 1 .

[0049] The water collection corridor 2 is provided with a slope, the bottom wall of the water collection corridor 2 is inclined, and a drainage side ditch 14 is arranged on the lower side of the bottom wall of the water collection corridor 2.

[0050] In this embodiment, the water collection corridor 2 is designed to have a single-sided downhill slope. The diameter of the water collection boreholes 13 is not less than 76 mm, the spacing between each water collection borehole 13 is 2 * 2 m, the depth of the water collection boreholes 13 is not less than 5 m. The water collection boreholes 13 along the circumferential direction are mainly used to reduce the water pressure behind the lining of the main tunnel, introduce water into the water collection corridor 2, and ensure the structural safety of the main tunnel 1. There are also water collection boreholes 13 in other orientations in the water collection corridor 2. Such water collection boreholes 13 are drilled from the water collection corridor 2 into the water-rich fissures or water-rich structures developed around the perimeter of the main tunnel 1.

[0051] Embodiment 3:

[0052] The basic content is equivalent to that of Embodiment 1, the difference is:

[0053] See Figures 6 to 9 , the water passage 3 is arc-shaped, a protective arch 15 is arranged on the side of the water passage 3 close to the main tunnel 1, concrete 8 is filled between the protective arch 15 and the gantry 6, and a support 16 is installed between the water passage 3 and the surrounding rock.

[0054] The protective arch includes a plurality of first steel bars 151, second steel bars 152, third steel bars 153 and fourth steel bars 154. The first steel bars 151 and second steel bars 152 match the shape of the water passage 3. A plurality of the first steel bars 151 are arranged along the length direction of the main tunnel 1, and a plurality of the second steel bars 152 are arranged along the length direction of the main tunnel 1. The first steel bars 151 are located outside the second steel bars 152. A plurality of the third steel bars 153 are arranged at intervals along the length direction of the main tunnel 1 and are respectively connected to the inner side of the first steel bars 151 and the outer side of the second steel bars 152 along the circumferential direction. Both ends of the fourth steel bar 154 are hook-shaped, and both ends of the fourth steel bar 154 are connected to the third steel bars 153. The first steel bars 151 and second steel bars 152 are respectively located inside the hook parts of the fourth steel bar 154.

[0055] In this embodiment, the clear height of the water passage 3 is 1 m. The first steel bars 151 and second steel bars 152 are the main steel bars, the third steel bars 153 are the distribution steel bars, and the fourth steel bars 154 are the stirrups. The spacing of the main steel bars along the line direction of the whole tunnel 1 is 100 mm, the circumferential spacing of the stirrups and distribution steel bars is 250 mm. The fourth steel bar 154 adopts a semi-circular hook, and its length is determined according to the actual lining thickness at the section where it is located. A geotextile and a waterproof board are arranged between the protective arch 15 and the lining of the main tunnel 1;

[0056] Since the water passage 3 is provided at the crown of the main tunnel 1, when the water outlet 5 is located on the side of the center line of the main tunnel 1 close to the drainage tunnel 17, that is, close to the water collection gallery 2, water will pass through the arc-shaped water passage 3 and be introduced into the water collection gallery 2 under the action of gravity; when the water outlet 5 of the main tunnel 1 is located on the side far from the water collection gallery 2, water will first gather in the water passage 3 at the crown of the main tunnel 1, and after the water head rises above the crown of the main tunnel 1, it will flow into the water collection gallery 2 along the arc-shaped water passage 3.

Claims

1. An arch wall off-wall drainage structure, characterized in that: The invention comprises a water collection gallery (2) and a water passage (3), wherein one end of the water collection gallery (2) is connected to the main tunnel (1) and the other end is connected to the drainage tunnel (17), the water passage (3) is located above the arch foot on the right side of the main tunnel (1) line to the side wall foot on the left side of the line, the water passage (3) is connected to the water collection gallery (2) through a drainage pipe (4), and the water passage (3) is connected to the longitudinal water-rich karst pipeline on the arch through multiple water outlets (5).

2. The arch wall off-wall drainage structure according to claim 1, characterized in that: The inner side wall of the water collection gallery (2) close to the main tunnel (1) is connected to a door frame (6); the inner bottom wall of the water collection gallery (2) close to the main tunnel (1) is provided with a head wall (7); the left and right sides of the head wall (7) and the space between the door frame (6) are filled with concrete (8); and a gap (9) for water to pass through is provided between the upper side of the head wall (7) and the door frame (6).

3. The arch wall off-wall drainage structure according to claim 2, characterized in that: The retaining wall (7) is in the shape of a step, and an anti-scouring platform (10) is connected between the foot of the retaining wall (7) and the inner bottom wall of the water collection gallery (2).

4. The arch wall off-wall drainage structure according to claim 2, characterized in that: The door frame (6) comprises two I-beam frames (11) spliced ​​to each other, the I-beam frame (11) is in an inverted U shape, and the two side walls of the I-beam frame (11) pass through the inner bottom wall of the water collection gallery (2) and are connected to a concrete foundation (12).

5. The arch wall off-wall drainage structure according to claim 1, characterized in that: The outer peripheral surface of the water collection gallery (2) close to the main tunnel (1) is provided with a plurality of water collection boreholes (13) along the circumferential direction.

6. The arch wall off-wall drainage structure according to claim 1, characterized in that: The water collection gallery (2) is provided with a slope, the bottom wall of the water collection gallery (2) is arranged at an incline, and a drainage side ditch (14) is arranged on the lower side of the bottom wall of the water collection gallery (2).

7. The arch wall off-wall drainage structure according to claim 2, characterized in that: The water passage (3) is arc-shaped, a protective arch (15) is provided on the side of the water passage (3) close to the main tunnel (1), concrete (8) is filled between the protective arch (15) and the door frame (6), and a bracket (16) is installed between the water passage (3) and the surrounding rock.

8. The arch wall off-wall drainage structure according to claim 7, characterized in that: The guard arch (15) comprises a plurality of first steel bars (151), a second steel bar (152), a third steel bar (153) and a fourth steel bar (154); the first steel bars (151) and the second steel bars (152) match the shape of the water passage (3); the plurality of first steel bars (151) are arranged along the length direction of the main hole (1); the plurality of second steel bars (152) are arranged along the length direction of the main hole (1); the first steel bars (151) are located outside the second steel bars (152); the plurality of third steel bars (153) are arranged at intervals along the length direction of the main hole (1) and are respectively connected to the inner side of the first steel bars (151) and the outer side of the second steel bars (152) in the circumferential direction; both ends of the fourth steel bar (154) are hook-shaped; both ends of the fourth steel bar (154) are connected to the third steel bar (153); the first steel bar (151) and the second steel bar (152) are respectively located inside the hook of the fourth steel bar (154).

9. A construction method for the arch wall off-wall drainage structure according to claim 2, characterized in that: The construction method comprises the following steps: Excavate the main tunnel (1), reveal the water outlet points (5) of the arch and the water outlet points (5) of the side wall, and observe the water volume at each water outlet point (5); The arch of the main tunnel (1) is expanded and excavated, and a water passage (3) is formed from the arch foot on the right side of the main tunnel (1) line to the upper side of the side wall foot on the left side of the line, and the water passage (3) is connected to all water outlet points (5) with large water output; A water collection gallery (2) is excavated so that the two ends of the water collection gallery (2) are respectively connected to the main tunnel (1) and the drainage tunnel (17); a drainage pipe (4) is pre-buried, and the two ends of the drainage pipe (4) are respectively connected to the water collection gallery (2) and the water passage (3).

10. The construction method of the arch wall off-wall drainage structure according to claim 9, characterized in that: When excavating the water collection gallery (2), a door frame (6) is installed on the inner side of the water collection gallery (2), and then a retaining wall (7) is set up near the main hole (1) of the excavated water collection gallery (2), and the space between the retaining wall (7) and the door frame (6) is backfilled and compacted with concrete (8).

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