Water conservancy project diversion tunnel blocking construction method

Abstract

The invention provides a water conservancy project diversion tunnel blocking construction method which comprises the following steps that a first diversion channel connected with a second diversion tunnel is formed in a first diversion tunnel, a first cofferdam is used for temporarily blocking a second water inlet, communicated with a water body, of the second diversion tunnel, and a first dry land construction area is formed; concrete is poured in the first dry land construction area, and the second water inlet is blocked; a second water diversion channel connected with the third diversion tunnel is formed in the first diversion tunnel, a second cofferdam is used for temporarily blocking a third water inlet, communicated with the water body, of the third diversion tunnel, and a second dry land construction area is formed; concrete is poured in the second dry land construction area, and the third water inlet is blocked; a third cofferdam is built between an inlet of the first water diversion channel and an inlet of the second water diversion channel, and a third dry land construction area is formed; and concrete is poured in the third dry land construction area, and the first water inlet is blocked. According to the method, plugging construction of the diversion tunnel can be achieved, the construction difficulty is low, and the cost is low.

Description

Technical Field

[0001] The invention relates to the technical field of water conservancy projects, and more specifically 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 a diversion tunnel with a larger span. In order to meet the needs of the diversion task, multiple diversion tunnels with small cross-sections are generally set up for diversion.

[0003] After the diversion tunnel has completed the task of diversion and water discharge, it is necessary to seal the diversion tunnel so that water can be stored and power generated faster to create higher benefits. The existing diversion tunnel is generally sealed by gates. The construction method of setting up a blocking gate is difficult, and this method requires concrete chamber operation, gate customization, installation, testing, acceptance and other work, which takes a long time and delays the time of water storage. In addition, the installation of the gate also requires diversion and interception work, which increases the construction cost and is not economical. Summary of the invention

[0004] 1. Technical issues to be resolved 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.

[0005] (II) Technical solution To achieve the above object, the technical solution adopted by the present invention is: The present invention provides a water conservancy project diversion hole plugging construction method, wherein at least three diversion holes are arranged along the flow direction of a water body, a first diversion hole is located between a second diversion hole and a third diversion hole, and the diversion hole is used to guide water flow from an upstream of a water body to a downstream of the water body. The water conservancy project diversion hole plugging construction method comprises the following steps: A first water diversion channel connected to the second diversion channel is opened in the first diversion tunnel, and a second water inlet of the second diversion tunnel connected to the water body is temporarily blocked by a first cofferdam to form a first dry land construction area between the outlet of the first water diversion channel and the second water inlet; pouring concrete in the first dry land construction area to block the second water inlet; A second water diversion channel connected to the third diversion channel is opened from the first diversion channel, and a third water inlet connecting the third diversion channel and the water body is temporarily blocked by a second cofferdam to form a second dry land construction area between the outlet of the second water 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, and forming a third dry land construction area at the place where the third cofferdam is away from the first water inlet of the first diversion tunnel; Concrete is poured in the third dry land construction area to block the first water inlet.

[0006] 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 block the water flowing out of the outlet of the first water diversion channel from moving in the direction of the second water inlet.

[0007] Preferably, the fourth cofferdam includes a first barrier and a second barrier disposed 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 water in the first water storage tank into the water body.

[0008] 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°.

[0009] 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°.

[0010] 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.

[0011] 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.

[0012] Preferably, pouring 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.

[0013] 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.

[0014] Preferably, the concrete is micro-expansive concrete.

[0015] (III) Beneficial effects The above technical solution of the present invention has at least the following advantages: 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 first diversion tunnel and the lower section of 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 blocking 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 blocking 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 to reduce the water pressure at the second cofferdam. The 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 the Bernoulli principle, the water will tend to flow out along the first water diversion channel and the second water diversion channel to reduce the water pressure at the third cofferdam, which is convenient for blocking the first water inlet in the third dry land construction area.

[0016] 2. The present invention only requires excavation work and construction of temporary cofferdams for plugging, and the construction difficulty is low. There is no need to use gates to plug the diversion tunnel, which reduces the construction cost investment and the construction process. It can improve the progress of diversion tunnel plugging construction, shorten the operation cycle, and efficiently complete the diversion tunnel plugging operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. 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 creative work.

[0018] Figure 1 It 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.

[0019] 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.

[0020] 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.

[0021] Figure 4 It 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.

[0022] 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.

[0023] 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.

[0024] Figure 7 is a schematic diagram of a blocking structure provided by an embodiment of the present invention.

[0025] 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.

[0026] Fig. 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.

[0027] The reference numerals in the figures are: 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

[0028] 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 in conjunction with 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.

[0029] 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.

[0030] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention, and do not indicate that a device or element must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0031] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating relative importance or indicating the number of technical features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. The specific implementation of the present invention is described in more detail below in conjunction with specific embodiments: like Figure 1 , Figure 2 and Figure 3 As shown, the arrow direction in the figure is the flow direction of the water body. The embodiment of the present invention provides a water conservancy project diversion hole plugging construction method, 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, and 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 water conservancy project diversion hole plugging construction method includes the following steps: A first water diversion channel 4 is opened from the first diversion tunnel 1 to connect with the second diversion tunnel 2, and a first cofferdam 5 is used to temporarily block the second water inlet 21 of the second diversion tunnel 2 connected with the water body, so as to form a first dry land construction area 22 between the outlet of the first water diversion channel 4 and the second water inlet 21; pouring concrete in the first dry land construction area 22 to block the second water inlet 21; A second water diversion channel 6 connected to the third diversion tunnel 3 is opened from the first diversion tunnel 1, and a third water inlet 31 connecting the third diversion tunnel 3 and the water body is temporarily blocked by a second cofferdam 7, so as to form a second dry land construction area 32 between the outlet of the second water diversion channel 6 and the third water inlet 31; pouring concrete in the second dry land construction area 32 to block the third water inlet 31; 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; Concrete is poured in the third dry land construction area 12 to block the first water inlet 11 .

[0032] Specifically, the first diversion tunnel 1 serves as a 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 flow in the water body flows through the first diversion tunnel 1 .

[0033] If the number of diversion holes is greater than three, such as Figure 5 and Figure 6 As shown, if there is still a fourth diversion tunnel 100, a third water diversion channel 110 connected to the fourth diversion tunnel 100 is opened from the second diversion tunnel 2, and a cofferdam is used to temporarily block the water inlet of the fourth diversion tunnel 100 connected to the water body, so as to form 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 there is still a fifth diversion tunnel 200, a fourth water diversion channel 210 connected to the fifth diversion tunnel 200 is opened from the third diversion tunnel 3, and a cofferdam is used to temporarily block the water inlet of the fifth diversion tunnel 200 connected to the water body, so as to form 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.

[0034] Preferably, a fourth cofferdam 9 is provided on a 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 in the direction of the second water inlet 21 .

[0035] Preferably, if Figure 4 As shown, the fourth cofferdam 9 includes a first barrier 91 and a second barrier 92 arranged at intervals, a first water storage tank 93 is dug between the first barrier 91 and the second barrier 92, a first water pump 94 is placed in the first water storage tank 93, and the first water pump 94 is used to pump the water in the first water storage tank 93 into the water body. The bottom surface of the first water storage tank 93 is lower than the bottom surface of the inner wall of the second diversion tunnel 2, so that the water flows into the first water storage tank 93 and is pumped out by the first water pump 94. By setting the first barrier 91 and the second barrier 92, the possibility of water flowing into the first dry land construction area 22 is further blocked. Even if water infiltrates, it will first flow into the first water storage tank 93 and then be pumped out by the first water pump 94, thereby ensuring the dryness of the construction ground in the first dry land construction area 22.

[0036] Preferably, if Figure 3As shown, there is a first preset angle A between the length direction of the first water diversion channel 4 and the flow direction of the water body, and the first preset angle A is 20° to 60°. The length direction of the first water diversion channel 4 is consistent with the flow direction of the water body, so that the water body flows smoothly along the length direction of the first water diversion channel 4.

[0037] Preferably, if Figure 3 As shown, there is a second preset angle B between the length 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°. The length direction of the second water diversion channel 6 is consistent with the flow direction of the water body, so that the water body flows smoothly along the length direction of the second water diversion channel 6.

[0038] Preferably, if Figure 8 As shown, the length direction of the first diversion tunnel 1 has a first inclination angle C with the horizontal plane, and the length direction of the second diversion tunnel 2 has 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 inclination of the second diversion tunnel 2 is relatively large. 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, the water flow is more inclined to enter the second diversion tunnel 2 along the first water diversion channel 4 and be discharged from the lower section of the second diversion tunnel 2 to avoid water backflow to the upper section of the second diversion tunnel 2, while reducing the drainage burden of the first diversion tunnel 1.

[0039] Preferably, if Fig. 9 As shown, the length direction of the first diversion tunnel 1 has a first inclination angle C with the horizontal plane, and the length direction of the third diversion tunnel 3 has 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 inclination of the second diversion tunnel 2 is relatively large. 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, the water flow is more inclined to enter the third diversion tunnel 3 along the second water diversion channel 6 and be discharged from the lower section of the third diversion tunnel 3 to avoid water backflow to the upper section of the third diversion tunnel 3, while reducing the drainage burden of the first diversion tunnel 1.

[0040] 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: 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 .

[0041] Preferably, if Figure 1 As shown, the first cofferdam 5 includes a third barrier 51 and a fourth barrier 52 arranged at intervals, and a second water storage tank 53 is dug between the third barrier 51 and the fourth barrier 52. A second water pump 54 is placed in the second water storage tank 53, and the second water pump 54 is used to pump the water in the second water storage tank 53 into the water body. The bottom surface of the second water storage tank 53 is lower than the bottom surface of the inner wall of the second diversion tunnel 2, so that the water flows into the second water storage tank 53 and is pumped out by the second water pump 54. By setting the third barrier 51 and the fourth barrier 52, the possibility of water flowing into the first dry land construction area 22 is further blocked. Even if water infiltrates, it will first flow into the second water storage tank 53 and then be pumped out by the second water pump 54, thereby ensuring the dryness of the construction ground in the first dry land construction area 22.

[0042] Preferably, the concrete is micro-expansive concrete. The expansion of micro-expansive concrete is required to be 120-150 microstrains, of which the minimum expansion required for crack prevention is 70-80 microstrains, and the remaining expansion produces a pre-compressive stress of about 0.6-0.7MPa on the constraint surface around the water inlet of the diversion tunnel, which correspondingly improves the bonding strength between the concrete and the wall of the diversion tunnel, and improves the shear strength of the bonding surface; if necessary, a trial mix of shrinkage compensating concrete is carried out according to the on-site raw materials to determine the physical and mechanical properties and mix ratio parameters.

[0043] 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 protection scope 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, the first diversion hole is located between the second diversion hole and the third diversion hole, and 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 diversion hole plugging construction method of the water conservancy project includes the following steps: A first water diversion channel connected to the second diversion channel is opened in the first diversion tunnel, and a second water inlet of the second diversion tunnel connected to the water body is temporarily blocked by a first cofferdam to form a first dry land construction area between the outlet of the first water diversion channel and the second water inlet; pouring concrete in the first dry land construction area to block the second water inlet; A second water diversion channel connected to the third diversion channel is opened from the first diversion channel, and a third water inlet connecting the third diversion channel and the water body is temporarily blocked by a second cofferdam to form a second dry land construction area between the outlet of the second water 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, and forming a third dry land construction area at the place where the third cofferdam is away from the first water inlet of the first diversion tunnel; Concrete is poured in the third dry land construction area to block the first water inlet.

2. The water conservancy project diversion tunnel plugging construction method according to claim 1, characterized in that: 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 in the direction of 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 that are spaced apart, 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 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 first cofferdam includes a third barrier and a fourth barrier that are spaced apart, 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.

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

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