A safe construction method for a dark-dig tunnel passing through a dike anti-seepage wall

Abstract

The present invention provides a safe construction method for a dark-cut tunnel passing through an anti-seepage wall, comprising the following steps: S1: digging at the upstream of the anti-seepage wall, the digging diameter gradually increases, and when reaching the anti-seepage wall, the maximum is 4.9m, and an upstream digging grid is installed at the digging position; S2: the anti-seepage wall is broken by a water drill, and the broken area is the area of ​​the second lining of the tunnel; S3: digging downstream of the anti-seepage wall, the length of the digging is the same as that of the upstream digging, the digging diameter is up to the diameter of the first lining of the tunnel, and a downstream digging grid is installed at the downstream digging position; S4: reverse digging downstream of the anti-seepage wall, so that the reverse digging position of the downstream section is symmetrical to the digging position of the upstream section along the anti-seepage wall, and the downstream digging grid is removed and the upstream digging grid is installed; S5: a water stop strip is pasted on the anti-seepage wall for waterproofing and anti-seepage. The present invention can effectively maintain the waterproof function of the original anti-seepage wall while ensuring the safety of dark-cut construction.

Description

Technical Field

[0001] The invention relates to a dark-digging tunnel method, in particular to a safe construction method for a dark-digging tunnel passing through an anti-seepage wall of a dike. Background Art

[0002] When constructing tunnels and underground construction projects, the corresponding space must be excavated first, and then the lining must be built in it. The shallow buried dark excavation method is a method of dark excavation of various types of underground caverns close to the surface. It is based on the transformation of geological conditions, focuses on controlling surface settlement, uses grids and sprayed anchors as initial support methods, and conducts tunnel construction in accordance with "pipe ahead, strict grouting, short excavation, strong support, fast closure, and frequent measurement".

[0003] When a dark-excavated tunnel passes through an important building, the geology changes, the surrounding rock stress is released, and the range of surrounding rock disturbance becomes larger. If no corresponding countermeasures are taken, it is easy to cause damage to the original building function. At the same time, the tunnel itself is prone to earth and rock collapse accidents. Therefore, construction safety when passing through buildings is the focus of construction. Summary of the invention

[0004] The present invention provides a safe construction method for the anti-seepage wall of a dark-cut tunnel passing through a middle embankment, which solves the problem of safe construction of the anti-seepage wall when the dark-cut tunnel passes through an important building. While ensuring the construction safety, it can effectively solve the construction problems such as the reduction or even loss of the original building function. It is a safe construction method that maintains the original building function. The technical scheme is as follows:

[0005] A safe construction method for a dark-excavated tunnel passing through a dike anti-seepage wall comprises the following steps:

[0006] S1: Excavate upstream of the cut-off wall, gradually increase the diameter of the excavated hole, and reach a maximum of 4.9m when reaching the cut-off wall, and install upstream excavation grids at the excavation site;

[0007] S2: The water drill breaks the anti-seepage wall, and the broken area is the area of ​​the secondary lining of the tunnel;

[0008] S3: Excavation downstream of the cut-off wall is the same length as the upstream excavation, and the maximum excavation diameter is the tunnel lining diameter, and downstream excavation grids are installed at the downstream excavation site;

[0009] S4: Back-dig the downstream of the cut-off wall so that the downstream back-dig part is symmetrical to the upstream excavation part along the cut-off wall, and remove the downstream excavation grid and install the upstream excavation grid;

[0010] S5: Waterstop strips are pasted on the anti-seepage wall to prevent waterproofing and seepage.

[0011] Furthermore, in step S1, the length of the expansion excavation upstream of the anti-seepage wall is 3-4 m, the diameter of the second lining of the tunnel remains unchanged at 3.7 m, and the diameter of the first lining of the tunnel gradually changes from 4.3 m to 4.9 m.

[0012] Furthermore, in step S1, the grid spacing of the upstream expansion grid is 0.4m~0.6m, and a small conduit is installed at each upstream expansion grid position. The lap length of the small conduit is not less than 1m, and the inclination angle is 20°~30° and faces the anti-seepage wall. The inclination angle of the small conduit close to the anti-seepage wall is adjusted to 90°.

[0013] Further, in step S2, breaking includes the following steps:

[0014] S21: Draw the water drill excavation mark on the anti-seepage wall, verify that the position of the mark to be cut is correct, and then use the water drill to cut in sections;

[0015] S22: The rhinestones are cut into 5 pieces. The upper part is cut into small pieces and divided into 4 pieces. The lower semicircular part is finally cut as a whole.

[0016] Furthermore, in step S3, after the downstream section of the cut-off wall is excavated to the diameter of the first lining of the tunnel, the diameter of the first lining of the tunnel is kept unchanged for 1m, and then a steel mesh is hung and concrete is sprayed to close the heading face.

[0017] Further, in step S4, the back-digging of the downstream of the cut-off wall includes the following steps:

[0018] S41: The starting point of the reverse excavation of the downstream section of the cut-off wall is the end point of the downstream section excavation. The reverse excavation length is the same as the excavation length of the upstream section of the cut-off wall. The hole diameter gradually increases and reaches a maximum of 4.9m when reaching the cut-off wall, which is symmetrical with the upstream section excavation.

[0019] S42: During the back-excavation process, the downstream expansion grid is removed. When the tunnel diameter changes, a downstream expansion grid is removed and an upstream expansion grid is installed.

[0020] Furthermore, in step S5, grooves are provided on the side walls and the inner wall of the anti-seepage wall, and water-swellable rubber strips are placed in the grooves, 2 on each side wall and 3 on the inner wall.

[0021] The size of the groove is 30mm×15mm, the size of the water-swellable rubber strip is 30mm×30mm, and half of the water-swellable rubber strip is embedded in the anti-seepage wall and the other half is exposed.

[0022] Furthermore, in step S2, the diameter of the water drilling hole is 1 / 8 to 1 / 6 of the thickness of the anti-seepage wall.

[0023] The safe construction method for a dark-digging tunnel passing through an anti-seepage wall of a middle embankment is simple and easy to operate, safe and reliable, can effectively ensure the safety of the anti-seepage wall, prevent the original building function from being reduced or even lost, and has better construction operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is the standard section of a dark excavated tunnel;

[0025] Figure 2 It is a schematic diagram of the process of the present invention;

[0026] Figure 3 This is the construction diagram of the upstream section of the anti-seepage wall from 4.3m to 4.9m;

[0027] Figure 4 This is a schematic diagram of the construction of water drilling to break the anti-seepage wall;

[0028] Figure 5 This is the construction diagram of the downstream section of the cut-off wall from 3.7m to 4.3m;

[0029] Figure 6 This is the construction diagram of the downstream section of the cut-off wall from 4.3m to 4.9m;

[0030] Figure 7 This is a construction diagram of sticking water stop strips on anti-seepage walls;

[0031] Explanation of the reference numerals: 1- tunnel first lining; 2- tunnel second lining; 3- anti-seepage wall; 4- upstream expansion grid; 5- small duct; 6- first cutting area; 7- second cutting area; 8- third cutting area; 9- fourth cutting area; 10- fifth cutting area; 11- downstream expansion grid; 12- standard grid; 13- starting point of downstream section back-excavation; 14- side wall of anti-seepage wall; 15- inner wall of anti-seepage wall. DETAILED DESCRIPTION

[0032] like Figure 1The standard section of the dark-cut tunnel shown in the figure is provided with a second tunnel lining 2 and a first tunnel lining 1 from the inside to the outside, and the dark-cut tunnel contacts an anti-seepage wall 3 that needs to be crossed. Among them, the second tunnel lining 2 is reinforced self-compacting concrete with a hole diameter of 3.7m, and the first tunnel lining 1 is steel grid sprayed concrete with a hole diameter of 4.3m. The present invention adopts a shallow buried dark-cut sprayed concrete first lining + inner lining steel pipe to cross the plastic concrete anti-seepage wall. The standard hole diameter of the first lining of the dark-cut tunnel is 4.3m, and the standard hole diameter of the second lining is 3.7m. Within the range of 3.5m upstream of the anti-seepage wall, the hole diameter of the dark-cut tunnel is expanded from 4.3m to 4.9m. After a circular hole with a diameter of 3.7m is excavated on the anti-seepage wall, 3.5m is continued to be excavated downstream, and the hole diameter of the tunnel is expanded from 3.7m to 4.3m. After excavating 1m of the standard section, the tunnel face was closed for back-excavation. The tunnel diameter was back-excavated from 4.3m to 4.9m, symmetrical with the upstream section of the anti-seepage wall. After the first lining was completed, 7 water-swelling rubber strips were set on the side walls of the anti-seepage wall, 2 on each side wall and 3 on the inner wall, for a total of 7 water-swelling rubber strips, to achieve the purpose of waterproofing and anti-seepage.

[0033] like Figure 2 As shown, the safe construction method of the dark excavation tunnel passing through the anti-seepage wall of the middle embankment specifically includes the following steps:

[0034] S1: Excavation is carried out upstream of the cut-off wall 3. The longer the excavation length, the safer the construction but the higher the cost. The shorter the excavation length, the lower the cost but the construction is unsafe. Taking into account the construction safety and cost, the excavation length is 3.5m, the maximum excavation diameter is 4.9m, and the upstream excavation grid 4 is installed at the excavation site. After excavation, the second lining 2 of the tunnel remains unchanged with a diameter of 3.7m, and the first lining 1 of the tunnel is gradually changed, with the diameter gradually changing from 4.3m to 4.9m.

[0035] The specific construction steps are as follows:

[0036] S11: Combination Figure 3 As shown, the upstream section of the cut-off wall 3 is 3.5 m long, and an upstream expansion grid 4 is installed at the upstream section of the expansion. The grid spacing of the upstream expansion grid 4 is 0.5 m, the length is 3.5 m, and there are 7 gradient grids in total. The diameter of the dark excavation is expanded from 4.3 m of the first lining 1 of the tunnel to 4.9 m.

[0037] S12: A small conduit 5 is installed at each grid position in the expanded upstream section. To ensure that the overlap length of the small conduit 5 meets the regulatory requirements and is at least 1 m, the inclination angle of the small conduit 5 in the expanded upstream section is directed toward the cut-off wall 3. After calculation, the inclination angle is adjusted to 20° to 30°. Near the cut-off wall, the inclination angle of the small conduit 5 is adjusted to 90° to prevent the small conduit 5 from damaging the cut-off wall.

[0038] S2: The water drill breaks the anti-seepage wall 3, and the broken area is the area of ​​the tunnel secondary lining 2;

[0039] The steps of drilling the anti-seepage wall 3 are as follows:

[0040] S21: Draw the marking line for water drill excavation, verify the position of the marking line to be cut, and use water drill to cut in sections.

[0041] S22: Considering the construction safety and transportation convenience, the diamond cutting is divided into 5 pieces, combined with Figure 4 As shown, in order to prevent the soil from gushing out from the opposite side, the upper part is cut into small pieces, which are divided into 4 parts, namely the first cutting area 6, the second cutting area 7, the third cutting area 8, and the fourth cutting area 9, which are cut in sequence. The semicircular part of the lower part is cut last. Considering the safety of the construction during cutting and the construction cost, it is cut as a whole as the fifth cutting area 10;

[0042] S23: The thickness of the anti-seepage wall is 800mm. To ensure construction safety, a small diameter water drill is used for the water drilling hole, generally 100-150mm.

[0043] S3: Excavation downstream of the cut-off wall. Since each grid in the excavation section requires a different grid mold, in order to save costs, the length of the downstream excavation is consistent with the upstream section, which is 3.5m. The maximum diameter of the excavated hole is 4.3m, and the downstream excavation grid 11 is installed at the excavation site. The specific construction steps are as follows:

[0044] S31: Figure 5 As shown, the downstream section of the cut-off wall 3 is 3.5 m long, and a downstream expansion grid 11 is installed at the downstream section of the expansion grid. The grid spacing of the downstream expansion grid 11 is 0.5 m, and there are 7 gradient grids in total. The diameter of the dark excavation tunnel is expanded from 3.7 m to 4.3 m.

[0045] S32: After the excavation is expanded to 4.3m downstream of the cut-off wall, that is, 3.5m downstream of the cut-off wall, the tunnel diameter is kept unchanged at 4.3m and excavated for 1m. A steel mesh is hung at 4.5m downstream of the cut-off wall and concrete is sprayed to seal the tunnel face;

[0046] S4: Back-dig downstream of the cut-off wall to make the downstream excavation part symmetrical to the upstream excavation part along the cut-off wall. The specific construction steps are as follows:

[0047] S41: Figure 6 As shown, the starting point of the reverse excavation of the downstream section of the cut-off wall is the end point of the downstream section excavation, the reverse excavation length is also 3.5m, and the tunnel diameter is reversed from 4.3m to 4.9m, which is symmetrical with the upstream section excavation.

[0048] S42: During the back-excavation process, in order to ensure construction safety, a pneumatic pick is used to break the downstream expansion grid 11. When the tunnel diameter changes, a downstream expansion grid 11 is removed and an upstream expansion grid 4 is installed.

[0049] S5: Paste water stop strips on the anti-seepage wall to prevent water seepage. The specific construction steps are as follows:

[0050] like Figure 7 As shown, 30mm×15mm grooves are ground out of the side wall 14 and the inner wall 15 of the anti-seepage wall by a grinding machine, and 30mm×30mm water-swellable rubber strips are placed, 2 strips on each side wall and 3 strips on the inner wall, a total of 7 strips, to ensure that half of the water-swellable rubber strips are embedded in the anti-seepage wall and half are exposed, so as to achieve the purpose of waterproofing and anti-seepage.

[0051] The safe construction method for a dark-digging tunnel passing through an anti-seepage wall of a middle embankment is simple and easy to operate, safe and reliable, can effectively ensure the safety of the anti-seepage wall, prevent the original building function from being reduced or even lost, and has better construction operation.

Claims

1. A safe construction method for a dark excavated tunnel passing through a dike anti-seepage wall, comprising the following steps: S1: Excavate upstream of the cut-off wall, gradually increase the diameter of the excavated hole, and reach a maximum of 4.9m when reaching the cut-off wall, and install upstream excavation grids at the excavation site; S2: The water drill breaks the anti-seepage wall, and the broken area is the area of ​​the secondary lining of the tunnel; S3: Excavation downstream of the cut-off wall is the same length as the upstream excavation, and the maximum excavation diameter is the tunnel lining diameter, and downstream excavation grids are installed at the downstream excavation site; S4: Back-dig the downstream of the cut-off wall so that the downstream back-dig part is symmetrical to the upstream excavation part along the cut-off wall, and remove the downstream excavation grid and install the upstream excavation grid; S5: Waterstop strips are pasted on the anti-seepage wall to prevent waterproofing and seepage.

2. The safe construction method for a dark-excavated tunnel passing through a dike anti-seepage wall according to claim 1 is characterized in that: In step S1, the length of the expansion excavation upstream of the cut-off wall is 3 to 4 m, the diameter of the second lining of the tunnel remains unchanged at 3.7 m, and the diameter of the first lining of the tunnel gradually changes from 4.3 m to 4.9 m.

3. The safe construction method for a dark-excavated tunnel passing through a dike anti-seepage wall according to claim 1 is characterized in that: In step S1, the grid spacing of the upstream expansion grid is 0.4m~0.6m, and a small conduit is installed at each upstream expansion grid position. The overlap length of the small conduit is not less than 1m, the inclination angle is 20°~30° and faces the anti-seepage wall. The inclination angle of the small conduit close to the anti-seepage wall is adjusted to 90°.

4. The safe construction method for a dark-excavated tunnel passing through a dike anti-seepage wall according to claim 1 is characterized in that: In step S2, breaking includes the following steps: S21: Draw the water drill excavation mark on the anti-seepage wall, verify that the position of the mark to be cut is correct, and then use the water drill to cut in sections; S22: The rhinestones are cut into 5 pieces. The upper part is cut into small pieces and divided into 4 pieces. The lower semicircular part is finally cut as a whole.

5. The safe construction method for a dark-excavated tunnel passing through a dike anti-seepage wall according to claim 1 is characterized in that: In step S3, after the downstream section of the cut-off wall is expanded to the diameter of the first lining of the tunnel, the diameter of the first lining of the tunnel is kept unchanged for 1m, and then a steel mesh is hung and concrete is sprayed to close the heading face.

6. The safe construction method for a dark-excavated tunnel passing through a dike anti-seepage wall according to claim 1 is characterized in that: In step S4, the back-digging of the downstream of the cut-off wall includes the following steps: S41: The starting point of the reverse excavation of the downstream section of the cut-off wall is the end point of the downstream section excavation. The reverse excavation length is the same as the excavation length of the upstream section of the cut-off wall. The hole diameter gradually increases and reaches a maximum of 4.9m when reaching the cut-off wall, which is symmetrical with the upstream section excavation. S42: During the back-excavation process, the downstream expansion grid is removed. When the tunnel diameter changes, a downstream expansion grid is removed and an upstream expansion grid is installed.

7. The safe construction method for a dark-excavated tunnel passing through a dike anti-seepage wall according to claim 1 is characterized in that: In step S5, grooves are provided on the side walls and the inner wall of the anti-seepage wall, and water-swellable rubber strips are placed in the grooves, 2 on each side wall and 3 on the inner wall.

8. The safe construction method for a dark-excavated tunnel passing through a dike anti-seepage wall according to claim 7 is characterized in that: The size of the groove is 30mm×15mm, the size of the water-swellable rubber strip is 30mm×30mm, and half of the water-swellable rubber strip is embedded in the anti-seepage wall and the other half is exposed.

9. The safe construction method for a dark-excavated tunnel passing through a dike anti-seepage wall according to claim 1 is characterized in that: In step S2, the diameter of the water drilling hole is 1 / 8 to 1 / 6 of the thickness of the anti-seepage wall.

Images