Construction method for plugging diversion tunnels in water conservancy projects

Abstract

The present invention provides a method for sealing diversion tunnels in a water conservancy project, comprising the following steps: opening a first diversion channel connecting a second diversion channel from a first diversion channel, temporarily blocking a second water inlet connecting the second diversion channel to a water body using a first cofferdam, thereby forming a first dry land construction area; pouring concrete in the first dry land construction area to block the second water inlet; opening a second diversion channel connecting a third diversion channel from the first diversion channel, temporarily blocking a third water inlet connecting the third diversion channel to a water body using a second cofferdam, thereby forming a second dry land construction area; pouring concrete in the second dry land construction area to block the third water inlet; constructing a third cofferdam between the entrances of the first diversion channel and the second diversion channel, thereby forming a third dry land construction area; and pouring concrete in the third dry land construction area to block the first water inlet. The present invention can achieve the sealing construction of diversion tunnels with low construction difficulty and low cost.

Description

Technical Field

[0001] The present invention relates to the technical field of water conservancy projects, and more particularly to a construction method for plugging a diversion tunnel in a water conservancy project. Background Art

[0002] During the construction of water conservancy and hydropower projects, in some construction scenarios, due to geological conditions or other factors, it is not suitable to open diversion tunnels with larger spans. In order to meet the needs of diversion tasks, multiple diversion tunnels with small cross-sections are generally set up for diversion.

[0003] After the constructed diversion tunnel has completed its task of diverting and releasing water, it is necessary to seal the diversion tunnel to accelerate water storage and power generation, thereby creating higher benefits. Existing diversion tunnel sealing methods generally use gates. This method of installing a blocking gate is difficult to construct and requires a long process of concrete chamber construction, gate customization, installation, testing, and acceptance, delaying the time it takes to close the gate and store water. Furthermore, gate installation requires diversion and interception work, increasing construction costs and making it uneconomical. Summary of the Invention

[0004] (1) Technical issues to be resolved

[0005] The technical problem to be solved by the present invention is that the existing blocking construction method of setting a blocking gate has the problems of great construction difficulty, long construction period and high construction cost.

[0006] (2) Technical solution

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] The present invention provides a construction method for plugging diversion holes in a water conservancy project. At least three diversion holes are provided along the flow direction of a water body. The first diversion hole is located between the second diversion hole and the third diversion hole. The diversion hole is used to guide water flow from the upstream of the water body to the downstream of the water body. The construction method for plugging diversion holes in a water conservancy project comprises the following steps:

[0009] A first diversion channel is opened from the first diversion tunnel to the second diversion tunnel, and a first cofferdam is used to temporarily block the second water inlet of the second diversion tunnel connected to the water body, so as to form a first dry land construction area between the outlet of the first diversion channel and the second water inlet;

[0010] pouring concrete in the first dry land construction area to block the second water inlet;

[0011] A second diversion channel is opened from the first diversion tunnel to the third diversion tunnel, and a second cofferdam is used to temporarily block the third water inlet connecting the third diversion tunnel to the water body, so as to form a second dry land construction area between the outlet of the second diversion channel and the third water inlet;

[0012] pouring concrete in the second dry land construction area to block the third water inlet;

[0013] Building a third cofferdam between the entrance of the first water diversion channel and the entrance of the second water diversion channel, forming a third dry land construction area at the location of the third cofferdam away from the first water inlet of the first diversion tunnel;

[0014] Concrete is poured in the third dry land construction area to seal the first water inlet.

[0015] Preferably, a fourth cofferdam is provided on a side of the outlet of the first water diversion channel close to the second water inlet, and the fourth cofferdam is used to prevent the water flowing out of the outlet of the first water diversion channel from moving toward the second water inlet.

[0016] Preferably, the fourth cofferdam includes a first barrier and a second barrier arranged at intervals, a first water storage tank is dug between the first barrier and the second barrier, a first water pump is placed in the first water storage tank, and the first water pump is used to pump the water in the first water storage tank into the water body.

[0017] Preferably, there is a first preset angle between the length direction of the first water diversion channel and the flow direction of the water body, and the first preset angle is 20° to 60°.

[0018] Preferably, there is a second preset angle between the length direction of the second water diversion channel and the flow direction of the water body, and the second preset angle is 20° to 60°.

[0019] Preferably, the length direction of the first diversion hole has a first inclination angle with the horizontal plane, the length direction of the second diversion hole has a second inclination angle with the horizontal plane, and the second inclination angle is greater than the first inclination angle.

[0020] Preferably, the length direction of the first diversion hole has a first inclination angle with the horizontal plane, the length direction of the third diversion hole has a third inclination angle with the horizontal plane, and the third inclination angle is greater than the first inclination angle.

[0021] Preferably, pouring concrete in the first dry land construction area to block the second water inlet specifically includes the following steps:

[0022] A crushed stone layer is laid in the first dry land construction area to cover the wet soil ground in the first dry land construction area, a cushion layer with a preset thickness is laid on the crushed stone layer, and then a concrete layer is poured on the cushion layer.

[0023] Preferably, the first cofferdam includes a third barrier and a fourth barrier arranged at intervals, a second water storage tank is dug between the third barrier and the fourth barrier, a second water pump is placed in the second water storage tank, and the second water pump is used to pump the water in the second water storage tank into the water body.

[0024] Preferably, the concrete is slightly expansive concrete.

[0025] (3) Beneficial effects

[0026] The above technical solution of the present invention has at least the following advantages:

[0027] 1. The present invention uses a first cofferdam to temporarily block the second water inlet connected to the water body by the second diversion tunnel, and sets a first water diversion channel to connect the lower sections of the first diversion tunnel and the second diversion tunnel, so that a first dry land construction area is formed between the outlet of the first water diversion channel and the second water inlet. The ground in the first dry land construction area is relatively dry, which is convenient for pouring concrete and achieving the blocking of the second water inlet; the first water diversion channel can enable the second diversion tunnel to still achieve the diversion function during the blocking construction process, so as to reduce the water pressure at the first cofferdam; similarly, the present invention uses a second cofferdam to temporarily block the third water inlet connected to the water body by the third diversion tunnel, and sets a second water diversion channel to connect the first diversion tunnel and the third diversion tunnel The lower section of the flow tunnel forms a second dry land construction area between the outlet of the second water diversion channel and the third water inlet. The ground in the second dry land construction area is relatively dry, which is convenient for pouring concrete and achieving the blocking of the third water inlet. The second water diversion channel can enable the third diversion tunnel to still achieve the diversion function during the blocking construction process, thereby reducing the water pressure at the second cofferdam. A third cofferdam is built between the entrance of the first water diversion channel and the entrance of the second water diversion channel. When water flows into the first diversion tunnel, according to Bernoulli's principle, the water will tend to flow out along the first water diversion channel and the second water diversion channel, thereby reducing the water pressure at the third cofferdam and facilitating the blocking of the first water inlet in the third dry land construction area.

[0028] 2. The present invention only requires excavation work and construction of cofferdams for temporary blocking, with low construction difficulty. There is no need to use gates to block the diversion tunnel, which reduces construction cost investment and construction procedures. It can improve the construction progress of the diversion tunnel blocking, shorten the operation cycle, and efficiently complete the diversion tunnel blocking operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 This is one of the construction flow charts of the water conservancy project diversion tunnel plugging construction method provided by the embodiment of the present invention.

[0031] Figure 2 This is the second construction flow chart of the water conservancy project diversion tunnel plugging construction method provided by the embodiment of the present invention.

[0032] Figure 3 This is the third construction flow chart of the water conservancy project diversion tunnel plugging construction method provided by the embodiment of the present invention.

[0033] Figure 4 This is one of the construction flow charts of a water conservancy project diversion tunnel plugging construction method provided by another embodiment of the present invention.

[0034] Figure 5 This is the second construction flow chart of the water conservancy project diversion tunnel plugging construction method provided by another embodiment of the present invention.

[0035] Figure 6 This is the third construction flow chart of the water conservancy project diversion tunnel plugging construction method provided by another embodiment of the present invention.

[0036] Figure 7 Schematic diagram of a blocking structure provided by an embodiment of the present invention.

[0037] Figure 8 It is a schematic diagram of the setting angles of the first diversion hole and the second diversion hole provided in an embodiment of the present invention.

[0038] Figure 9 It is a schematic diagram of the setting angles of the first diversion hole and the third diversion hole provided in an embodiment of the present invention.

[0039] The reference numerals in the figures are:

[0040] 1. First diversion tunnel; 2. Second diversion tunnel; 3. Third diversion tunnel; 4. First water diversion channel; 5. First cofferdam; 6. Second water diversion channel; 7. Second cofferdam; 8. Third cofferdam; 9. Fourth cofferdam; 11. First water inlet; 12. Third dry land construction area; 21. Second water inlet; 22. First dry land construction area; 31. Third water inlet; 32. Second dry land construction area; 51. Third barrier; 52. Fourth barrier; 53. Second water storage tank; 54. Second water pump; 91. First barrier; 92. Second barrier; 93. First water storage tank; 94. First water pump; 221. Gravel layer; 222. Cushion layer; 223. Concrete layer. DETAILED DESCRIPTION

[0041] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0042] It should be noted that when an element is referred to as being “fixed to” or “disposed on” another element, it may be directly located on the other element or indirectly located on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0043] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate that the device or element must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0044] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating relative importance or the number of technical features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined. The following is a more detailed description of the specific implementation of the present invention in conjunction with specific embodiments:

[0045] like Figure 1 、 Figure 2 and Figure 3 As shown, the arrow direction in the figure indicates the flow direction of the water body. An embodiment of the present invention provides a construction method for plugging a diversion hole in a water conservancy project. At least three diversion holes are provided along the flow direction of the water body. The first diversion hole 1 is located between the second diversion hole 2 and the third diversion hole 3. The diversion hole is used to guide the water flow from the upstream of the water body to the downstream of the water body. The construction method for plugging a diversion hole in a water conservancy project includes the following steps:

[0046] A first diversion channel 4 is opened from the first diversion tunnel 1 to the second diversion tunnel 2. A first cofferdam 5 is used to temporarily block the second water inlet 21 of the second diversion tunnel 2 from the water body, thereby forming a first dry land construction area 22 between the outlet of the first diversion channel 4 and the second water inlet 21.

[0047] Concrete is poured in the first dry land construction area 22 to block the second water inlet 21;

[0048] A second diversion channel 6 is opened from the first diversion tunnel 1 to the third diversion tunnel 3. A second cofferdam 7 is used to temporarily block the third water inlet 31 connecting the third diversion tunnel 3 to the water body, thereby forming a second dry land construction area 32 between the outlet of the second diversion channel 6 and the third water inlet 31.

[0049] Pour concrete in the second dry land construction area 32 to block the third water inlet 31;

[0050] A third cofferdam 8 is constructed between the entrance of the first water diversion channel 4 and the entrance of the second water diversion channel 6, and a third dry land construction area 12 is formed at the third cofferdam 8 away from the first water inlet 11 of the first diversion tunnel 1;

[0051] Concrete is poured in the third dry land construction area 12 to block the first water inlet 11 .

[0052] Specifically, the first diversion tunnel 1 serves as the main diversion tunnel, and its diameter can be set to be larger than the diameter of the second diversion tunnel 2 / the third diversion tunnel 3 to ensure that most of the water in the water body flows through the first diversion tunnel 1.

[0053] If the number of diversion holes is greater than three, such as Figure 5 and Figure 6 As shown, if a fourth diversion tunnel 100 is also present, a third water diversion channel 110 is opened from the second diversion tunnel 2 to connect with the fourth diversion tunnel 100, and a cofferdam is used to temporarily block the water inlet of the fourth diversion tunnel 100 connected to the water body, thereby forming a fourth dry land construction area between the outlet of the third water diversion channel 110 and the water inlet of the fourth diversion tunnel 100; concrete is poured in the fourth dry land construction area to block the water inlet of the fourth diversion tunnel 100; similarly, if a fifth diversion tunnel 200 is also present, a fourth water diversion channel 210 is opened from the third diversion tunnel 3 to connect with the fifth diversion tunnel 200, and a cofferdam is used to temporarily block the water inlet of the fifth diversion tunnel 200 connected to the water body, thereby forming a fifth dry land construction area between the outlet of the fourth water diversion channel 210 and the water inlet of the fifth diversion tunnel 200; concrete is poured in the fifth dry land construction area to block the water inlet of the fifth diversion tunnel 200.

[0054] Preferably, a fourth cofferdam 9 is provided on the side of the outlet of the first water diversion channel 4 close to the second water inlet 21 , and the fourth cofferdam 9 is used to block the water flowing out of the outlet of the first water diversion channel 4 from moving toward the second water inlet 21 .

[0055] Preferably, if Figure 4 As shown, the fourth cofferdam 9 includes a first barrier 91 and a second barrier 92 spaced apart. A first water tank 93 is excavated between the first barrier 91 and the second barrier 92. A first water pump 94 is placed within the first water tank 93, which is used to pump water from the first water tank 93 into the water body. The bottom of the first water tank 93 is lower than the bottom of the inner wall of the second diversion tunnel 2, allowing water to flow into the first water tank 93 and be pumped out by the first water pump 94. The first barrier 91 and the second barrier 92 further prevent water from flowing into the first dry land construction area 22. Even if water does infiltrate, it will first flow into the first water tank 93 and then be pumped out by the first water pump 94, thus ensuring that the construction surface in the first dry land construction area 22 remains dry.

[0056] Preferably, if Figure 3 As shown, a first preset angle A is formed between the length direction of the first water diversion channel 4 and the flow direction of the water body. The first preset angle A is 20° to 60°. This makes the length direction of the first water diversion channel 4 and the flow direction of the water body aligned, so that the water body flows smoothly along the length direction of the first water diversion channel 4.

[0057] Preferably, if Figure 3 As shown, a second preset angle B is formed between the longitudinal direction of the second water diversion channel 6 and the flow direction of the water body, and the second preset angle B is 20° to 60°. This makes the longitudinal direction of the second water diversion channel 6 and the flow direction of the water body aligned, so that the water body flows smoothly along the longitudinal direction of the second water diversion channel 6.

[0058] Preferably, if Figure 8 As shown, the length direction of the first diversion tunnel 1 forms a first inclination angle C with the horizontal plane, and the length direction of the second diversion tunnel 2 forms a second inclination angle D with the horizontal plane, and the second inclination angle D is greater than the first inclination angle C. Through the above technical solution, the second diversion tunnel 2 has a larger inclination. Under the action of gravity, the flow rate of water in the second diversion tunnel 2 will be greater than the flow rate of water in the first diversion tunnel 1. According to Bernoulli's principle, the greater the flow rate, the lower the pressure. Under the action of the pressure difference, water is more likely to flow along the first water diversion channel 4 into the second diversion tunnel 2 and be discharged from the lower section of the second diversion tunnel 2, thereby preventing water from flowing back to the upper section of the second diversion tunnel 2 and reducing the drainage burden of the first diversion tunnel 1.

[0059] Preferably, if Figure 9As shown, the length direction of the first diversion tunnel 1 forms a first inclination angle C with the horizontal plane, and the length direction of the third diversion tunnel 3 forms a third inclination angle E with the horizontal plane, and the third inclination angle E is greater than the first inclination angle C. Through the above technical solution, the second diversion tunnel 2 has a greater inclination. Under the action of gravity, the flow rate of water in the third diversion tunnel 3 will be greater than the flow rate of water in the first diversion tunnel 1. According to Bernoulli's principle, the greater the flow rate, the lower the pressure. Under the action of the pressure difference, water is more likely to flow along the second water diversion channel 6 into the third diversion tunnel 3 and be discharged from the lower section of the third diversion tunnel 3, thereby preventing water from flowing back to the upper section of the third diversion tunnel 3 and reducing the drainage burden of the first diversion tunnel 1.

[0060] Preferably, if Figure 7 As shown, pouring concrete in the first dry land construction area 22 to block the second water inlet 21 specifically includes the following steps:

[0061] A crushed stone layer 221 is laid in the first dry land construction area 22 to cover the wet soil surface in the first dry land construction area 22 , a cushion layer 222 with a preset thickness is laid on the crushed stone layer 221 , and then a concrete layer 223 is poured on the cushion layer 222 .

[0062] Preferably, if Figure 1 As shown, the first cofferdam 5 includes a third barrier 51 and a fourth barrier 52 spaced apart. A second water tank 53 is excavated between the third and fourth barriers 51, 52. A second water pump 54 is placed within the second water tank 53, which is used to pump water from the second water tank 53 into the water body. The bottom of the second water tank 53 is lower than the bottom of the inner wall of the second diversion tunnel 2, allowing water to flow into the second water tank 53 and be pumped out by the second water pump 54. The third and fourth barriers 51, 52 further prevent water from flowing into the first dry land construction area 22. Even if water does infiltrate, it will first flow into the second water tank 53 and then be pumped out by the second water pump 54, thus ensuring that the construction surface in the first dry land construction area 22 remains dry.

[0063] Preferably, the concrete is micro-expansive concrete. The expansion of micro-expansive concrete is required to be 120 to 150 microstrains, of which the minimum expansion required to prevent cracking is 70 to 80 microstrains. The remaining expansion generates a pre-compressive stress of approximately 0.6 to 0.7 MPa on the restraining surface around the water inlet of the diversion tunnel, which correspondingly improves the bond strength between the concrete and the diversion tunnel wall and the shear strength of the bond surface. If necessary, a trial mix of shrinkage-compensating concrete should be conducted based on the on-site raw materials to determine the physical and mechanical properties and mix ratio parameters.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A construction method for plugging a diversion tunnel in a water conservancy project, characterized in that: At least three diversion holes are provided along the flow direction of the water body, wherein the first diversion hole is located between the second diversion hole and the third diversion hole. The diversion hole is used to guide the water flow from the upstream of the water body to the downstream of the water body. The construction method for plugging the diversion hole of the water conservancy project includes the following steps: A first diversion channel is opened from the first diversion tunnel to the second diversion tunnel, and a first cofferdam is used to temporarily block the second water inlet of the second diversion tunnel connected to the water body, so as to form a first dry land construction area between the outlet of the first diversion channel and the second water inlet; pouring concrete in the first dry land construction area to block the second water inlet; A second diversion channel is opened from the first diversion tunnel to the third diversion tunnel, and a second cofferdam is used to temporarily block the third water inlet connecting the third diversion tunnel to the water body, so as to form a second dry land construction area between the outlet of the second diversion channel and the third water inlet; pouring concrete in the second dry land construction area to block the third water inlet; Building a third cofferdam between the entrance of the first water diversion channel and the entrance of the second water diversion channel, forming a third dry land construction area at the location of the third cofferdam away from the first water inlet of the first diversion tunnel; pouring concrete in the third dry land construction area to block the first water inlet; The first cofferdam includes a third barrier and a fourth barrier spaced apart from each other, a second water storage tank is dug between the third barrier and the fourth barrier, a second water pump is placed in the second water storage tank, and the second water pump is used to pump the water in the second water storage tank into the water body.

2. The water conservancy project diversion tunnel plugging construction method according to claim 1, characterized in that: A fourth cofferdam is provided on the side of the outlet of the first water diversion channel close to the second water inlet, and the fourth cofferdam is used to prevent the water flowing out of the outlet of the first water diversion channel from moving toward the second water inlet.

3. The water conservancy project diversion tunnel plugging construction method according to claim 2, characterized in that: The fourth cofferdam includes a first barrier and a second barrier arranged at intervals, a first water storage tank is dug between the first barrier and the second barrier, a first water pump is placed in the first water storage tank, and the first water pump is used to pump the water in the first water storage tank into the water body.

4. The water conservancy project diversion tunnel plugging construction method according to claim 1, characterized in that: There is a first preset angle between the length direction of the first water diversion channel and the flow direction of the water body, and the first preset angle is 20° to 60°.

5. The water conservancy project diversion tunnel plugging construction method according to claim 1, characterized in that: There is a second preset angle between the length direction of the second water diversion channel and the flow direction of the water body, and the second preset angle is 20° to 60°.

6. The water conservancy project diversion tunnel plugging construction method according to claim 1, characterized in that: The length direction of the first diversion hole has a first inclination angle with the horizontal plane, the length direction of the second diversion hole has a second inclination angle with the horizontal plane, and the second inclination angle is greater than the first inclination angle.

7. The water conservancy project diversion tunnel plugging construction method according to claim 1, characterized in that: The length direction of the first diversion hole has a first inclination angle with the horizontal plane, the length direction of the third diversion hole has a third inclination angle with the horizontal plane, and the third inclination angle is greater than the first inclination angle.

8. The water conservancy project diversion tunnel plugging construction method according to claim 1, characterized in that: The pouring of concrete in the first dry land construction area to block the second water inlet specifically includes the following steps: A crushed stone layer is laid in the first dry land construction area to cover the wet soil ground in the first dry land construction area, a cushion layer with a preset thickness is laid on the crushed stone layer, and then a concrete layer is poured on the cushion layer.

9. The water conservancy project diversion tunnel plugging construction method according to claim 1, characterized in that: The concrete is slightly expansive concrete.

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