Temporary closure structure and method for upstream of diversion tunnel

Abstract

The application discloses a temporary blocking structure and method for the upstream of a diversion tunnel, which comprises a concrete structure of the diversion tunnel, a diversion pipe is arranged on the bottom of the upstream end of the concrete structure along the water flow direction, the diversion pipe is positioned with the concrete structure through a water-blocking limiting device, a blocking door is arranged on the outside of the shoulder of the upstream end of the concrete structure, the upstream end of the diversion pipe extends out of the blocking door, a first blocking wall body is arranged on the downstream side of the blocking door, a second blocking wall body is arranged on the downstream side of the first blocking wall body and located at the tail end of the diversion pipe, and concrete is poured between the first blocking wall body and the second blocking wall body. Through the structure, the upstream of the diversion tunnel can be quickly and temporarily blocked, and construction conditions are provided for the permanent blocking of the downstream.

Description

TECHNICAL FIELD

[0001] The application relates to a temporary plugging structure and method for an upstream diversion tunnel. BACKGROUND

[0002] A diversion tunnel of a certain hydropower station is seriously seepage due to geological reasons. As of February 18, 2017, the water level of the upstream reservoir is 1351.63 m, the water level of the diversion tunnel outlet is 1299.97 m, the water depth in the diversion tunnel is 1.5-3 m, and the seepage flow is as high as 4.82 m³ / s. The seepage amount of the diversion tunnel increases with the increase of the water level of the upstream reservoir, and the construction of the plugging concrete cannot be carried out at present. Therefore, it is necessary to temporarily plug the upstream of the diversion tunnel to carry out the construction of the plugging concrete.

[0003] Chinese patent document CN108316260A discloses a diversion tunnel plugging structure and method based on karst topography. A first temporary plugging head, a second temporary plugging head and a permanent plugging head are sequentially arranged in the concrete lining of the original diversion tunnel along the water flow direction. A water retaining steel gate is installed upstream of the first temporary plugging head, and a stoplog gate is installed after the water retaining steel gate. The stoplog gate is positioned by a plurality of vertical columns. A bottom layer drainage steel pipe and a top layer drainage steel pipe are arranged at the bottom of the concrete lining of the original diversion tunnel. The two layers of drainage steel pipes are stacked. A first disc valve is installed at the water outlet of the top layer drainage steel pipe. Two second disc valves and a third disc valve are installed at the water outlet of the bottom layer drainage steel pipe. The structure has the following disadvantages. The four drainage pipes of the bottom layer drainage steel pipe and the top layer drainage steel pipe make the whole drainage pipe in place. In a narrow environment, the installation is difficult and the risk is high. No effective water retaining structure is arranged between the bottom layer drainage steel pipe and the top layer drainage steel pipe. When the first temporary plugging head is poured with concrete, the concrete is washed away by the water flow, and it is not easy to pour the concrete. Although the interval between the drainage pipes and the two side surfaces are sealed by membrane bags, the sealing effect is not ideal, especially the position below the drainage steel pipe is below the water surface, and cannot be effectively filled, so that piping can occur, or the water flow directly flows to the downstream through the gap, which is not conducive to the pouring of the concrete. The gap below the drainage steel pipe cannot be handled by using geotextile and cotton wadding.

[0004] In addition, Chinese patent document CN108385627B discloses a diversion tunnel plugging construction method for a hydropower station based on karst topography. The drainage steel pipe is still hoisted into the water as a whole. Although it is disclosed that a water stop steel plate is arranged upstream and downstream of the drainage steel pipe, the disadvantage is that when pouring, the bag 14 is filled with cement to form a downstream cofferdam. Therefore, when pouring, the drainage steel pipe is blocked, the water head upstream rises, the high water pressure penetrates the membrane bag grouting sealing structure between the drainage steel pipes and the gap of the stoplog gate, a large amount of water seeps, and the pouring of the concrete is not conducive. SUMMARY

[0005] The technical problem solved by the present application is to solve the problems in the background art, and provide a temporary plugging structure for the upstream of a diversion tunnel, which can quickly and temporarily plug the upstream of the diversion tunnel.

[0006] Another technical problem solved by the present application is to provide a construction method using the temporary plugging structure for the upstream of the diversion tunnel.

[0007] In order to achieve the above technical features, the purpose of the present application is achieved as follows: the temporary plugging structure for the upstream of the diversion tunnel comprises a concrete structure of the diversion tunnel, a diversion pipe is installed at the bottom of the upstream end of the concrete structure along the water flow direction, the diversion pipe is positioned with the concrete structure through a water-blocking limiting device, a plugging door is installed on the outside of the shoulder of the upstream end of the concrete structure, the upstream end of the diversion pipe extends out of the plugging door, a first plugging wall is arranged on the downstream side of the plugging door, a second plugging wall is arranged on the downstream side of the first plugging wall at the tail end of the diversion pipe, and concrete is poured between the first plugging wall and the second plugging wall.

[0008] The diversion pipe comprises a plurality of lower diversion pipes and a plurality of upper diversion pipes, the lower diversion pipes and the upper diversion pipes are installed in layers, and a first valve and a second valve are respectively installed at the downstream ends of the lower diversion pipes and the upper diversion pipes.

[0009] The water-blocking limiting device comprises a limiting beam and a limiting plate, the limiting beam comprises an upstream beam at the shoulder and a downstream beam at the downstream end, the upstream beam and the downstream beam are respectively arranged at the bottom of the concrete structure and fixedly connected with the concrete structure, the limiting plate is installed on the outer wall of the diversion pipe and corresponds to the positions of the upstream beam and the downstream beam, the limiting plate is located upstream of the upstream beam and the downstream beam, and a sealing insert in the shape of an I-beam is inserted between the limiting plates adjacent to the upstream beam and the downstream beam.

[0010] Two limiting plates are spaced apart upstream of the upstream beam and the downstream beam, and the sealing insert is installed between the left and right adjacent limiting plates.

[0011] The plugging door comprises a support beam, a plugging beam and a sliding groove beam, a plurality of support beams are arranged on the outside of the shoulder of the concrete structure in a longitudinal direction, the upper and lower ends of the support beam extend into the rock mass, the sliding groove beam is located on the upstream side of the support beam and is installed on both sides of the diversion tunnel, a limiting sliding groove for installing the plugging beam is formed between the sliding groove beam and the support beam close to the side wall of the diversion tunnel, and the diversion pipe is located below the plugging beam.

[0012] The support beam, the plugging beam and the sliding groove beam are all welded from two or more segments.

[0013] The first and second plugging walls are bagged cement filling walls, both sides of which are provided with baffle plates for closure, the first plugging wall has a width of 1-1.5 m and a height of 4-5 m, and the second plugging wall has a width of 0.5-1 m and a height of 3-4 m.

[0014] The first and second plugging walls are concrete pouring walls, both sides of which are provided with composite baffle plates for closure, the first plugging wall has a width of 1-1.5 m and a height of 4-5 m, and the second plugging wall has a width of 0.5-1 m and a height of 3-4 m.

[0015] The limiting plate and the side wall of the diversion tunnel are filled with bagged cement, and the gap is stuffed with cotton wadding.

[0016] A method for plugging a diversion tunnel by using the temporary upstream plugging structure of the diversion tunnel, comprising the following steps,

[0017] S1. installing a scaffold inside the concrete structure of the diversion tunnel;

[0018] S2. installing a plugging door outside the shoulder of the upstream end of the concrete structure;

[0019] S21. installing five support beams, wherein the support beams are installed in two parts, the lower part is installed first, and then the upper part is connected and installed, and the upper and lower ends of the support beams extend into the rock mass;

[0020] S22. welding a limiting steel at a position 3.5 m away from the bottom surface of the concrete structure, stacking multiple plugging beams on the upper side of the limiting steel, and leaving a space for installing the diversion pipe on the lower side of the limiting steel;

[0021] S3. installing the diversion pipe, wherein the diversion pipe comprises multiple lower diversion pipes and multiple upper diversion pipes;

[0022] S31. installing 3-5 hoisting beams in the direction of water flow along the cross-sectional direction at a height of 1.6-2 m from the assembly platform of the scaffold;

[0023] S32. fixedly installing an upstream cross beam on the bottom surface of the upstream end of the diversion pipe and fixedly installing a downstream cross beam on the bottom surface of the downstream end of the diversion pipe, and the top parts of the upstream cross beam and the downstream cross beam are at the same height;

[0024] S33. aligning and welding the segmented lower diversion pipes on the assembly platform, and welding the limiting plates on the outer wall;

[0025] S34. hanging a hoist on each hoisting beam, and the hoist on each hoisting beam is aligned with the lower diversion pipes, after the hoist completely hoists the lower diversion pipes, the corresponding cross bar of the assembly platform is removed, and then the lower diversion pipes are hoisted into the water one by one;

[0026] S35. When the lower diversion pipe is lowered, the upstream limiting plate is clamped on the upstream side of the bottom upstream crossbeam, and the downstream limiting plate is clamped on the upstream side of the bottom downstream crossbeam. In order to prevent the lower diversion pipe from drifting downstream during the lowering process, two reinforcing bars are driven into the tunnel wall at the same elevation as the lower diversion pipe assembly platform on both sides. A steel crossbeam is connected to the two reinforcing bars. Diagonal bracing is set on both sides of the downstream side of the steel crossbeam. Four steel wire ropes are pulled out from the steel crossbeam, and each steel wire rope is pulled to hold one lower diversion pipe.

[0027] S35. Install the crossbars on the assembly platform, transport the upper guide pipes in sections to the assembly platform, align and weld them together, and weld the limiting plates on the outer wall.

[0028] S36. Install the upper-level diversion pipes one by one using the same method as hoisting the lower-level diversion pipes;

[0029] S37. A sealing plug is inserted between the lower and upper guide pipes located between adjacent limiting plates;

[0030] S4. Continue installing the sealing beam to close the space under the limiting steel section;

[0031] S41. Weld a suspension beam onto the support beam located above the limiting steel. Two second hoists are suspended on the suspension beam. The lower end of the second hoists is suspended from the sealing beam installed in S22. Then separate the limiting steel from the support beam, lower the second hoists, and place the sealing beam close to the upper side of the upper guide pipe.

[0032] S42. Then install the chute beams on both sides of the upstream side to form a chute, weld the sealing beam to the support beam, and then install and weld the remaining sealing beams in the upper part. The sealing beams need to be installed up to the top of the tunnel.

[0033] S5. Upstream and downstream water retention;

[0034] S51. The sidewalls of the limiting plate 33 and the diversion hole are filled with bagged cement and the gaps are sealed with cotton wool;

[0035] S52. Bamboo treads and geomembrane are inserted into the frame pipes at the upstream and downstream to form a composite partition for sealing. A concrete retaining wall is poured above the drainage pipe using a guide pipe to form the first sealing wall and the second sealing wall.

[0036] S6. Underwater concrete pouring;

[0037] S61. Underwater concrete pouring using the guide pipe method: In the gaps between adjacent guide pipes and between the guide pipes and the rock surface, multiple rows of steel pipes are placed underwater as guide pipes. The lower part of the steel pipes is 0.3m away from the bottom plate surface, and the upper part is connected to a funnel. If the concrete cannot spread during the pouring process, the steel pipes are raised.

[0038] S62. When the upper layer diversion pipe is ready to pass water, the temporary plugging upstream is completed.

[0039] The present application has the following advantages:

[0040] 1. By setting the diversion pipe, the upstream water is discharged through the diversion pipe, thereby providing conditions for pouring concrete above; setting the water-blocking limiting device not only blocks the turbulent water flow outside the diversion pipe, providing conditions for later underwater pouring, but also plays a limiting role on the diversion pipe, preventing it from being displaced by the water flow after installation is completed; the blocking door blocks the water flow from the upstream and provides installation protection for later construction. Since the blocking door cannot be completely sealed, the first plugging wall is needed to close the blocking door again, and the second plugging wall is set to block the downstream water flow, thereby facilitating the pouring of concrete between the first and second plugging walls. Through the above structure, the upstream of the diversion tunnel can be quickly temporarily plugged, providing construction conditions for downstream permanent plugging.

[0041] 2. The upstream water flow is preliminarily cut off between the limiting plates on adjacent diversion pipes, and there is still water flow in the gap between the limiting plates, which is closed by the I-shaped sealing insert.

[0042] 3. Two limiting plates are respectively arranged at the upstream and downstream ends, forming a filling cavity between the two limiting plates. After the sealing insert is installed, concrete or bagged cement can be poured in the filling cavity between the two limiting plates. The concrete or bagged cement is not easily washed away by water, and the sealing effect is better. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 It is a longitudinal section structure diagram of the diversion tunnel of the present application.

[0044] Figure 2 It is a top view structure diagram of the diversion tunnel of the present application.

[0045] Figure 3 It is a front view structure diagram of the present application for installing the blocking door.

[0046] Figure 4 It is a side view structure diagram of the present application for installing the blocking door.

[0047] Figure 5 It is a front view structure diagram of the present application for hoisting the diversion pipe.

[0048] Figure 6 It is a top view structure diagram of the present application for installing the sealing insert between the limiting plates of the diversion pipe.

[0049] Figure 7 It is a front view structure diagram of the present application after the blocking door is installed.

[0050] Figure 8 Structure diagram of the first embodiment of the first sealing wall of the present application.

[0051] Figure 9 Structure diagram of the second embodiment of the first sealing wall of the present application.

[0052] Figure 10 Structure diagram of the first sealing wall and the second sealing wall when pouring concrete.

[0053] Figure 11 Structure diagram of the present application when pouring concrete underwater.

[0054] Figure 12 Structure diagram of the present application when pouring concrete underwater and pumping up the steel pipe.

[0055] In the figure: concrete structure 10, shoulder 11, limiting beam 20, upstream cross beam 21, downstream cross beam 22, flow guide pipe 30, lower flow guide pipe 31, first valve 311, upper flow guide pipe 32, second valve 321, limiting plate 33, sealing insert 34, sealing band 341, sealing door 40, support beam 41, limiting profiled steel 412, sealing beam 42, sliding groove beam 43, suspension beam 44, second hoist 45, first sealing wall 50, partition plate 51, composite partition plate 52, steel pipe 53, second sealing wall 60, concrete 70, scaffold 80, assembly platform 81, hoisting beam 90, hoist 91. DETAILED DESCRIPTION

[0056] The embodiments of the present application will be further described below in conjunction with the accompanying drawings.

[0057] Embodiment 1:

[0058] Reference Figures 1-12, the upstream temporary blocking structure of the diversion tunnel comprises a concrete structure 10 of the diversion tunnel, a diversion pipe 30 is installed at the bottom of the upstream end of the concrete structure 10 along the water flow direction, the diversion pipe 30 is positioned with the concrete structure 10 through a water-blocking limiting device, a blocking door 40 is installed outside the shoulder 11 of the upstream end of the concrete structure 10, the upstream end of the diversion pipe 30 extends out of the blocking door 40, a first blocking wall 50 is arranged at the downstream side of the blocking door 40, a second blocking wall 60 is arranged at the downstream direction of the first blocking wall 50 and located at the tail end of the diversion pipe 30, and the concrete 70 is poured between the first blocking wall 50 and the second blocking wall 60. By arranging the diversion pipe 30, the upstream water is discharged through the diversion pipe 30, thereby providing conditions for pouring the concrete 70 above; the water-blocking limiting device not only blocks the turbulent water flow outside the diversion pipe 30 to provide conditions for underwater pouring in the later period, but also plays a limiting role on the diversion pipe 30 to prevent the diversion pipe 30 from being displaced by the water flow after the installation is completed; the blocking door 40 blocks the water flow from the upstream and provides installation protection for the later construction. Since the blocking door 40 cannot be completely sealed, the first blocking wall 50 is needed to reseal the blocking door 40, and the second blocking wall 60 is arranged to block the downstream water, thereby facilitating the pouring of the concrete 70 between the first blocking wall 50 and the second blocking wall 60.

[0059] Specifically, referring to Figure 3 , the diversion pipe 30 comprises four lower diversion pipes 31 and four upper diversion pipes 32, the lower diversion pipes 31 and the upper diversion pipes 32 are installed in layers, and the downstream ends of the lower diversion pipes 31 and the upper diversion pipes 32 are respectively provided with first valves 311 and second valves 321. The first valves 311 and the second valves 321 play a role in closing the lower diversion pipes 31 and the upper diversion pipes 32 in the later period, thereby facilitating the pouring of the concrete at the downstream end.

[0060] Specifically, referring to Figure 1 , 6The water blocking limiting device comprises a limiting beam 20 and a limiting plate 33. The limiting beam 20 comprises an upstream beam 21 located at the shoulder 11 and a downstream beam 22 located at the downstream end. The upstream beam 21 and the downstream beam 22 are respectively located at the bottom of the concrete structure 10 and fixedly connected with the concrete structure 10. The limiting plate 33 is installed on the outer wall of the diversion pipe 30 and corresponds to the positions of the upstream beam 21 and the downstream beam 22. The limiting plate 33 is located upstream of the upstream beam 21 and the downstream beam 22. A I-shaped sealing insert 34 is installed between the limiting plates 33 adjacent to the upstream beam 21 and the downstream beam 22. The limiting plates 33 between the adjacent diversion pipes 30 preliminarily cut off the upstream water flow. There is still water flow at the gap between the limiting plates 33. The water flow is closed by the I-shaped sealing insert 34. The installation is simple and convenient. During installation, the limiting plate 33 is clamped upstream of the upstream beam 21 and the downstream beam 22, thereby positioning the diversion pipe 30. Further, the sealing insert 34 is provided with a sealing band 341 on the side surface of the limiting plate 33. The sealing effect is better.

[0061] Referring to Figure 6 The limiting plate 33 is spaced apart and provided with two limiting plates upstream of the upstream beam 21 and the downstream beam 22. The sealing insert 34 is installed between the left and right adjacent limiting plates 33 and penetrates the limiting plates 33 arranged in layers. Two limiting plates 33 are respectively arranged at the upstream and downstream ends. A filling cavity is formed between the two limiting plates 33. After the sealing insert 34 is installed, concrete or bagged cement can be poured in the filling cavity between the two limiting plates 33. The concrete or bagged cement is not easy to be washed away by water. The sealing effect is better.

[0062] It should be noted that the limiting plate 33 close to the side wall of the diversion hole is spaced apart from the hole wall. This is convenient for later plugging.

[0063] Referring to Figures 2-4 , 7, the sealing door 40 comprises a support beam 41, a sealing beam 42 and a sliding groove beam 43. The support beam 41 is provided with a plurality of support beams 41. The support beams 41 are longitudinally spaced apart and installed on the outside of the shoulder 11 of the concrete structure 10. The upper and lower ends of the support beam 41 respectively extend into the rock mass. The sliding groove beam 43 is located on the upstream side of the support beam 41 and is installed on both sides of the diversion hole. The sliding groove beam 43 and the support beam 41 close to the side wall of the diversion hole form a limiting sliding groove for installing the sealing beam 42. The diversion pipe 30 is located below the sealing beam 42. The support beam 41 is used to support the structure of the entire sealing door 40. The sealing beam 42 is used to seal the hole. The sliding groove beam 43 and the support beam 41 close to the side wall of the diversion hole form a limiting sliding groove for installing the sealing beam 42. This is convenient for installing the upper sealing beam 42 and can clamp the sealing beam 42 from both sides, thereby improving the stability. Specifically, the gap between the upper and lower sealing beams 42 is fully welded. The sealing beam 42 is welded with the support beam 41.

[0064] In order to facilitate transportation and installation, in the preferred embodiment, the support beams 41, the blocking beams 42 and the chute beams 43 are all welded into two or more sections. In use, the short sections of the support beams 41, the blocking beams 42 and the chute beams 43 are transported to the installation location, and are welded into the required length during installation.

[0065] Referring to Figure 8 , the first blocking wall 50 and the second blocking wall 60 are bagged cement filling walls, both upstream and downstream sides of which are closed by the partition plates 51. The first blocking wall 50 has a width of 1-1.5 m and a height of 4-5 m (completely blocking the hole), and the second blocking wall 60 has a width of 0.5-1 m and a height of 3-4 m. The partition plates 51 can be bamboo treads or wooden formworks.

[0066] Referring to Figure 9 , in another embodiment, the first blocking wall 50 and the second blocking wall 60 are concrete pouring walls, both sides of which are closed by the composite partition plates 52. The first blocking wall 50 has a width of 1-1.5 m and a height of 4-5 m, and the second blocking wall 60 has a width of 0.5-1 m and a height of 3-4 m. The use of concrete pouring has higher strength and better sealing performance.

[0067] The limiting plate 33 is filled with bagged cement and is sealed with cotton wadding to the side wall of the diversion tunnel. The limiting plate 33 is underwater blocked with the side wall of the hole.

[0068] Embodiment Two:

[0069] Referring to Figures 1-12 , a method for blocking a diversion tunnel using the temporary upstream blocking structure of the diversion tunnel, comprising the following steps,

[0070] S1. Installing a scaffold 80 inside the concrete structure 10 of the diversion tunnel;

[0071] S2. Installing a blocking door 40 outside the shoulder 11 of the upstream end of the concrete structure 10;

[0072] S21. Installing five support beams 41, wherein the support beams 41 are installed in two parts, the lower part of the support beam 41 is installed first, and then the upper part of the support beam 41 is installed in a butt joint, and the upper and lower ends of the support beam 41 extend into the rock mass respectively;

[0073] S22. Welding a limiting steel 412 at a distance of 3.5 m from the bottom plate 3 of the concrete structure 10, and stacking a plurality of blocking beams 42 on the upper side of the limiting steel 412, and leaving a space for installing the diversion pipe 30 on the lower side of the limiting steel 412;

[0074] S3. Installing the diversion pipe 30, wherein the diversion pipe 30 includes four lower layer diversion pipes 31 and four upper layer diversion pipes 32;

[0075] S31. Install 3-5 hoisting beams 90 along the water flow direction in the cross-sectional direction at a height of 1.6-2 m from the assembly platform 811 of the scaffold 80;

[0076] S32. Fix the upstream cross beam 21 on the bottom surface of the upstream end of the flow guide pipe 30, and fix the downstream cross beam 22 on the bottom surface of the downstream end of the flow guide pipe 30. The top of the upstream cross beam 21 and the downstream cross beam 22 are at the same height;

[0077] S33. Align and weld the segmented lower layer flow guide pipe 31 on the assembly platform 81, and weld the limiting plate 33 on the outer wall;

[0078] S34. Hang a hoppet 91 on each hoisting beam 90, and the hoppet 91 on each hoisting beam 90 is aligned with the lower layer flow guide pipe 31. After the hoppet 91 completely hoists the lower layer flow guide pipe 31, the corresponding cross bar of the assembly platform 81 is removed, and then the lower layer flow guide pipe 31 is hoisted into the water one by one;

[0079] S35. When the lower layer flow guide pipe 31 is settled, the limiting plate 33 located upstream is clamped on the upstream side of the upstream cross beam 21 on the bottom, and the limiting plate 33 located downstream is clamped on the upstream side of the downstream cross beam 22 on the bottom. In order to prevent the lower layer flow guide pipe 31 from drifting downstream during the lowering process, two insertion bars are punched into the wall on both sides of the lower layer flow guide pipe 31 at the same height as the assembly platform, a profile steel is horizontally arranged on the two insertion bars, inclined braces are arranged on the downstream side of the profile steel, and four steel wires are pulled out from the profile steel, with each steel wire pulling one lower layer flow guide pipe 31;

[0080] S35. Install the cross bar on the recovered assembly platform 81, transport the upper layer flow guide pipe 32 to the assembly platform 81 in sections, align and weld, assemble and weld the limiting plate 33 on the outer wall;

[0081] S36. Install the upper layer flow guide pipe 32 one by one in the same way as hoisting the lower layer flow guide pipe 31;

[0082] S37. Insert the sealing plug 34 between the lower layer flow guide pipe 31 and the upper layer flow guide pipe 32 located between the adjacent limiting plates 33;

[0083] S4. Continue to install the blocking beam 42 to close the space below the limiting profile steel 412;

[0084] S41. Weld a suspension beam 44 on the support beam 41 located above the limiting profile steel 412, hang two second hoppets 45 on the suspension beam 44, and hang the second hoppet 45 at the lower end on the blocking beam 42 installed in S22. Then separate the limiting profile steel 412 from the support beam 41, lower the second hoppet 45, and drop the blocking beam 42 to tightly adhere to the upper side of the upper layer flow guide pipe 32;

[0085] S42. Install the chute beams 43 on both sides of the upstream, form the chute, and weld the blocking beams 42 and the support beams 41. Then, install and weld the remaining blocking beams 42 on the upper part. The blocking beams 42 need to be installed to the top of the hole;

[0086] S5. Block the upstream and downstream;

[0087] S51. Fill the gap between the limiting plate 33 and the side wall and bottom wall of the diversion tunnel with bagged cement, and plug the gap with cotton wool;

[0088] S52. Form the composite partition 52 by inserting bamboo steps into the pipe frame on the upstream and downstream, adding geotextile membrane, and adding bamboo steps. Use a conduit to pour concrete retaining wall above the drain pipe to form the first blocking wall 50 and the second blocking wall 60;

[0089] S6. Pouring concrete underwater;

[0090] S61. Use the conduit method to pour concrete underwater: place multiple rows of steel pipes 53 as conduits underwater in the gap between adjacent diversion pipes 30 and the gap between the diversion pipes 30 and the rock surface. The lower part of the steel pipe 53 is 0.3m away from the bottom plate, and the upper part is connected to the funnel. If the concrete cannot spread during pouring, the steel pipe 53 will be raised;

[0091] S62. When the upper diversion pipe 32 is overflown, the temporary blocking on the upstream is completed.

Claims

1. Temporary closure structure upstream of a diversion tunnel, comprising a concrete structure (10) of the diversion tunnel, characterized in that, The upstream end bottom of the concrete structure (10) is provided with a guide pipe (30) in the water flow direction, the guide pipe (30) is positioned with the concrete structure (10) through a water blocking limiting device, the shoulder (11) of the upstream end of the concrete structure (10) is provided with a blocking door (40) on the outside, the upstream end of the guide pipe (30) extends out of the blocking door (40), the downstream side of the blocking door (40) is provided with a first blocking wall (50), the downstream direction of the first blocking wall (50) is provided with a second blocking wall (60) at the tail end of the guide pipe (30), and the first blocking wall (50) and the second blocking wall (60) are poured with concrete (70) therebetween. The water blocking limiting device comprises a limiting beam (20) and a limiting plate (33), the limiting beam (20) comprises an upstream cross beam (21) at the shoulder (11) and a downstream cross beam (22) at the downstream end, the upstream cross beam (21) and the downstream cross beam (22) are respectively located at the bottom of the concrete structure (10) and are fixedly connected with the concrete structure (10), the limiting plate (33) is installed on the outer wall of the guide pipe (30) and corresponds to the positions of the upstream cross beam (21) and the downstream cross beam (22), the limiting plate (33) is located upstream of the upstream cross beam (21) and the downstream cross beam (22), and a sealing insert (34) in the shape of an I-beam is inserted between the limiting plates (33) adjacent to the upstream cross beam (21) and the downstream cross beam (22). The guide pipe (30) comprises a plurality of lower guide pipes (31) and a plurality of upper guide pipes (32), the lower guide pipes (31) and the upper guide pipes (32) are installed in layers, and the downstream ends of the lower guide pipes (31) and the upper guide pipes (32) are respectively provided with first valves (311) and second valves (321).

2. The temporary upstream closure structure of a diversion tunnel according to claim 1, characterized in that: The limiting plate (33) is provided with two limiting plates at the upstream of the upstream cross beam (21) and the downstream cross beam (22), and the sealing insert (34) is installed between the left and right adjacent limiting plates (33).

3. The temporary upstream closure structure of a diversion tunnel according to claim 1, characterized in that: The blocking door (40) comprises a support beam (41), a blocking beam (42) and a chute beam (43), the support beam (41) is provided with a plurality of support beams, the support beams (41) are longitudinally spaced and installed on the outside of the shoulder (11) of the concrete structure (10), the upper and lower ends of the support beam (41) extend into the rock mass respectively, the chute beam (43) is located on the upstream side of the support beam (41) and is installed on both sides of the guide hole, the limiting chute for installing the blocking beam (42) is formed between the chute beam (43) and the support beam (41) close to the side wall of the guide hole, and the guide pipe (30) is located on the lower side of the blocking beam (42).

4. The temporary upstream closure structure of a diversion tunnel according to claim 3, characterized in that: The support beam (41), the blocking beam (42) and the chute beam (43) are all welded from two or more sections.

5. The temporary upstream closure structure of a diversion tunnel according to claim 1, characterized in that: The first blocking wall (50) and the second blocking wall (60) are bagged cement filling walls, the upstream and downstream sides of the bagged cement filling walls are closed by the partition plates (51), the width of the first blocking wall (50) is 1-1.5 m, the height is 4-5 m, the width of the second blocking wall (60) is 0.5-1 m, and the height is 3-4 m.

6. The temporary upstream closure structure of a diversion tunnel according to claim 1, characterized in that: The first and second sealing walls (50, 60) are concrete pouring walls, both sides of the concrete pouring walls are closed by composite partition plates (52), the first sealing wall (50) has a width of 1-1.5 m and a height of 4-5 m, and the second sealing wall (60) has a width of 0.5-1 m and a height of 3-4 m.

7. The temporary upstream closure structure of a diversion tunnel according to claim 1, characterized in that: The limiting plates (33) are filled with bagged cement and are plugged with cotton wadding.

8. A method for conducting the closure of a diversion tunnel by using the temporary closure structure upstream of the diversion tunnel according to claim 3, characterized in that, The method comprises the following steps, S1. installing a scaffold (80) inside the concrete structure (10) of the diversion tunnel; S2. installing a sealing door (40) outside the shoulder (11) at the upstream end of the concrete structure (10); S21. installing five support beams (41), wherein the support beams (41) are installed in two parts, the lower part of the support beam (41) is installed first, and then the upper part of the support beam (41) is connected and installed, and the upper and lower ends of the support beam (41) extend into the rock mass; S22. welding a limiting profile steel (412) at a position 3.5 m away from the bottom surface of the concrete structure (10), stacking a plurality of sealing beams (42) on the upper side of the limiting profile steel (412), and leaving a space for installing the diversion pipe (30) on the lower side of the limiting profile steel (412); S3. installing the diversion pipe (30), wherein the diversion pipe (30) comprises a plurality of lower diversion pipes (31) and a plurality of upper diversion pipes (32); S31. installing 3-5 hoisting beams (90) in the direction of water flow in the cross-sectional direction at a height of 1.6-2 m from the assembly platform (81) of the scaffold (80); S32. fixing and installing an upstream cross beam (21) at the bottom surface of the upstream end of the diversion pipe (30) and a downstream cross beam (22) at the bottom surface of the downstream end of the diversion pipe (30), and the top parts of the upstream cross beam (21) and the downstream cross beam (22) are at the same height; S33. aligning and welding the segmented lower diversion pipes (31) on the assembly platform (81), and welding the limiting plates (33) on the outer wall; S34. suspending a number of hoists (91) equal to the number of the lower diversion pipes (31) on each hoisting beam (90), and aligning the hoists (91) on each hoisting beam (90) with the lower diversion pipes (31), respectively, after the lower diversion pipes (31) are completely hoisted by the hoists (91), the corresponding cross bars of the assembly platform (81) are removed, and then the lower diversion pipes (31) are hoisted into the water one by one; S35. When the lower diversion pipes (31) are settled, the limiting plates (33) located upstream are clamped on the upstream side of the upstream cross beam (21) at the bottom, and the limiting plates (33) located downstream are clamped on the upstream side of the downstream cross beam (22) at the bottom; wherein, in order to prevent the lower diversion pipes (31) from drifting downstream during the lowering process, two insertion bars are punched into the tunnel wall at the same elevation as the assembly platform of the lower diversion pipes (31) on both sides of the tunnel wall, a profile steel is horizontally arranged on the two insertion bars, inclined supports are arranged on the downstream side of the profile steel, the profile steel pulls out four steel wires, and each steel wire pulls one lower diversion pipe (31). S35. Install the crossbar on the assembling platform (81), and transport the upper diversion pipe (32) to the assembling platform (81) in sections, align and weld, and weld the limiting plate (33) on the outer wall; S36. Install the upper diversion pipe (32) one by one in the same way as the lower diversion pipe (31) is hoisted; S37. Insert the sealing insert (34) between the lower diversion pipe (31) and the upper diversion pipe (32) located between the adjacent limiting plates (33); S4. Continue to install the blocking beam (42) to close the space below the limiting profiled steel (412); S41. Weld the suspension beam (44) on the support beam (41) above the limiting profiled steel (412), and hang two second hoists (45) on the suspension beam (44), the lower end of the second hoist (45) is hung on the blocking beam (42) installed in S22, then separate the limiting profiled steel (412) from the support beam (41), lower the second hoist (45), and drop the blocking beam (42) to closely adhere to the upper side of the upper diversion pipe (32); S42. Install the chute beam (43) on the upstream two sides again to form a chute, weld the blocking beam (42) with the support beam (41), and then install and weld the remaining blocking beams (42) on the upper part, and the blocking beam (42) needs to be installed to the top of the hole; S5. Block the upstream and downstream; S51. Fill the gap between the limiting plate (33) and the side wall of the diversion tunnel with bagged cement, and use cotton wadding to seal the gap; S52. Form a composite partition (52) by inserting a bamboo tread plate into the pipe in the row frame on the upstream and downstream, adding a geotextile membrane, and adding a bamboo tread plate, and use a conduit to pour concrete on the drainage pipe to form a first blocking wall (50) and a second blocking wall (60); S6. Underwater concrete pouring; S61. Use the conduit method for underwater concrete pouring: place multiple rows of steel pipes (53) as conduits in the gap between adjacent diversion pipes (30) and the gap between the diversion pipe (30) and the rock surface, with the lower part of the steel pipe (53) being 0.3m away from the bottom surface and the upper part being connected to a funnel, and if the concrete cannot spread during pouring, the steel pipe (53) will be raised; S62. When the upper diversion pipe (32) is in flow, the temporary blocking on the upstream is completed.

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