A rock layer drainage device for an underground powerhouse of a pumped storage power station and a construction method thereof

Abstract

The present invention discloses a rock stratum drainage device for an underground powerhouse of a pumped-storage power station, comprising a plurality of drop-down pipes, a plurality of first drainage branches, a plurality of water collecting pipes and a plurality of second drainage branches; each first drainage branch pipe is laid on the outer wall of a water diversion steel branch pipe and the installation direction of the first drainage branch pipe is consistent with the direction of the corresponding water diversion steel branch pipe, the drainage end of the drop-down pipe extends into the underground powerhouse of the pumped-storage power station, the drainage outlets of at least three spaced-apart second drainage branches are connected to the corresponding drop-down pipes, the drainage ends of at least three spaced-apart water collecting pipes are respectively connected to a corresponding first drainage branch pipe; at least three spaced-apart first drainage branches are connected via the water inlet of a corresponding second drainage branch pipe. The present invention also discloses a construction method for a rock stratum drainage device for an underground powerhouse of a pumped-storage power station. The present invention avoids water seepage in the upstream side wall of the underground powerhouse and can keep the underground powerhouse dry.

Description

Technical Field

[0001] The invention relates to the technical field of underground powerhouse drainage of a pumped storage project, and in particular to a rock stratum drainage device for an underground powerhouse of a pumped storage power station and a construction method thereof. Background Art

[0002] The underground powerhouse of a pumped-storage power station generally has a drainage system installed in the water diversion steel branch pipe area of ​​the surrounding rock on the upstream side of the underground powerhouse to ensure the safety, dryness and suitable operating environment of the upstream side wall of the underground powerhouse and even the entire underground powerhouse area.

[0003] Conventional designs include steel pipe wall drainage systems and steel branch pipe rock wall drainage systems. These conventional drainage systems have the following shortcomings:

[0004] (1) There may be certain safety hazards. The steel pipe wall drainage system and the steel branch pipe rock wall drainage system are connected by longitudinal angle steel and longitudinal water collecting pipes. The water collecting pipes are used to lead out the water diversion steel branch pipe construction branch hole. There is a risk that the underground water in the underground powerhouse mountain will be led to the upstream side wall of the underground powerhouse along the loose circle of the surrounding rock of the water diversion steel branch pipe, the contact surface between the steel pipe and the backfill concrete outside the steel pipe, the contact surface between the backfill concrete and the surrounding rock, and the steel pipe external drainage system.

[0005] (2) The monitoring data is not intuitive and the treatment measures are limited in effect. The conventional drainage system water collection pipe is led out from the plug of the branch hole of the water diversion steel branch pipe. The pressure gauge and gate valve installed at the pipe mouth are far away from the upstream side wall of the underground powerhouse. The monitoring data cannot reflect its actual pressure, and the treatment measures of opening the gate valve to discharge water are limited in effect.

[0006] (3) Construction causes distortion of monitoring data and difficulty in daily maintenance. The longitudinal angle steel and rock drainage holes of the steel pipe wall drainage system and the steel branch pipe rock wall drainage system are easily blocked during the grouting construction process, resulting in distortion of monitoring data and difficulty in maintenance.

[0007] (4) When this conventional solution is used, water seepage often occurs on the upstream side wall of the plant during the actual water filling process. In order to block the water seepage channel, the passive treatment measure is to temporarily drill holes in the upstream side wall of the plant and fill them with grout. This construction plan is relatively cumbersome, and the treatment effect is not ideal, and water seepage often occurs repeatedly. Summary of the invention

[0008] In view of this, it is necessary to propose a rock drainage device and a construction method for the underground powerhouse of a pumped-storage power station to address the above-mentioned problems, so as to solve the shortcomings of the above-mentioned background technology, thereby solving the technical problem of how to avoid water seepage in the upstream side wall of the underground powerhouse of the pumped-storage power station and keep the powerhouse dry.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] The present invention provides a rock formation drainage device for an underground powerhouse of a pumped storage power station, which is applied to the rock formation upstream / above the underground powerhouse of the pumped storage power station, in which a water diversion steel branch pipe of the pumped storage power station is arranged, and the rock formation drainage device comprises a plurality of drop down pipes, a plurality of first drainage branch pipes, a plurality of water collecting pipes and a plurality of second drainage branch pipes;

[0011] Each first drainage branch pipe is laid on the outer wall of the water diversion steel branch pipe and the installation direction of the first drainage branch pipe is consistent with the direction of the corresponding water diversion steel branch pipe. The drainage end of the drop down pipe extends into the underground powerhouse of the pumped storage power station. The drop down pipe is connected to each drainage outlet respectively. The drainage ends of at least three spaced-apart water collecting pipes are connected to a corresponding first drainage branch pipe respectively; at least three spaced-apart first drainage branch pipes are connected through the water inlet of a corresponding second drainage branch pipe;

[0012] Each water collecting pipe and the corresponding first drainage branch pipe form an inverted T-shaped three-way water pipe structure, and each water collecting pipe extends into the corresponding drilled rock formation borehole channel;

[0013] The rock formation drilling channel is used to collect groundwater from the rock formation near the water diversion steel branch pipe;

[0014] The water collecting pipe is used to collect groundwater in the rock formation drilling channel;

[0015] The first drainage branch pipe is used to collect groundwater from a water collecting pipe connected to the first drainage branch pipe;

[0016] The second drainage branch pipe is used to collect groundwater from the first drainage branch pipe connected to the second drainage branch pipe;

[0017] The drop down pipe is used to collect groundwater in each second drainage branch pipe, and to drain the collected groundwater to the drainage channel of the underground powerhouse of the pumped storage power station by means of water level drop drainage.

[0018] Furthermore, the rock layer drainage device also includes a pressure gauge and a gate valve, and the pressure gauge and the gate valve are both connected in series to the drop down pipe extending into the underground powerhouse of the pumped storage power station.

[0019] Furthermore, the angle between the tangent line of the virtual intersection of the water collecting pipe and the corresponding first drainage branch pipe is in the range of 85°-90°.

[0020] Furthermore, each first drainage branch pipe is connected to three water collecting pipes.

[0021] Furthermore, the water collecting pipe is connected to the corresponding first drainage branch pipe via a tee.

[0022] Furthermore, each rock formation drilling channel is located in the rock formation near the outer wall of the water diversion steel branch pipe above the underground powerhouse of the pumped storage power station.

[0023] Furthermore, the water collecting pipe is a seamless metal pipe.

[0024] Furthermore, the gap between the opening of each rock formation drilling channel close to the first drainage branch pipe and the corresponding water collecting pipe is sealed by cement mortar.

[0025] The present invention also provides a construction method for the rock stratum drainage device of the underground powerhouse of the pumped storage power station as described above, comprising the following steps:

[0026] S1, drilling a number of rock formation drilling channels at the rock formation location corresponding to the water collecting pipe to be installed, and then executing S2;

[0027] S2, embedding the rock formation drilling channels into the water collecting pipe one by one, and then executing S3;

[0028] S3, plugging the gap between the opening of each rock formation drilling channel close to the first drainage branch pipe and the corresponding water collecting pipe with cement mortar, and then executing S4;

[0029] S4, connect the drainage ends of at least three water collecting pipes to the corresponding first drainage branch pipes, connect the second drainage branch pipes to the drainage ends of at least three corresponding separated water collecting pipes, connect the drainage outlets of at least three separated second drainage branch pipes to the corresponding drop down pipes, and extend the drainage ends of the drop down pipes into the underground powerhouse of the pumped storage power station.

[0030] Further, before S1 or after S4, the method further includes:

[0031] S100, the drainage end of the drop down pipe is arranged in the underground powerhouse of the pumped storage power station, and the pressure gauge and the gate valve are sequentially connected in series to the drop down pipe extending into the underground powerhouse of the pumped storage power station.

[0032] The beneficial effects of the present invention are:

[0033] The invention solves the problem of water seepage in the upstream side wall of the underground powerhouse of the pumped storage power station during the water filling process, and meets the requirements of the safety of the upstream side wall of the underground powerhouse of the pumped storage power station and the dry and suitable operating environment of the underground powerhouse of the pumped storage power station.

[0034] The present invention solves the problem that the monitoring data cannot reflect the real pressure value because the pressure gauge and the gate valve are far away from the upstream side wall of the underground powerhouse of the pumped storage power station, and the effect of the water discharge treatment measure of opening the gate valve is limited. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the cross-sectional structure of a rock stratum drainage device of an underground powerhouse of a pumped storage power station according to the present invention;

[0036] Figure 2 It is a structural schematic diagram of a rock formation drilling channel and a seamless metal pipe involved in the present invention;

[0037] Figure 3 It is a schematic diagram of the three-dimensional structure of a rock stratum drainage device of an underground powerhouse of a pumped storage power station according to the present invention;

[0038] Figure 4 for Figure 3 A-view enlarged schematic diagram;

[0039] Description of reference numerals:

[0040] Collecting pipe 1; first drainage branch pipe 2; drop down pipe 3; pressure gauge 4; gate valve 5; rock formation drilling channel 7; tee piece 1b; cement mortar 1c; underground powerhouse of pumped storage power station 8; water diversion steel branch pipe 9; drainage channel 6 in the lower floor of the powerhouse; second drainage branch pipe 10. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be further clearly and completely described in combination with the embodiments of the present invention. It should be noted that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0042] It should be understood that the directions or positional relationships indicated by terms such as "upper", "lower", "front", "back", "left", and "right" 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 simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present invention.

[0043] The terms "first", "second", "third", "fourth", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the definition of "first", "second", "third", "fourth" features may explicitly or implicitly include one or more of the features.

[0044] Example 1

[0045] like Figure 1-Figure 4 As shown:

[0046] This embodiment provides a rock formation drainage device for an underground powerhouse of a pumped storage power station, which is applied to the rock formation upstream / above the underground powerhouse 8 of the pumped storage power station, in which a water diversion steel branch pipe 9 of the pumped storage power station is arranged, and the rock formation drainage device includes a plurality of drop down pipes 3, a plurality of first drainage branch pipes 2, a plurality of water collecting pipes 1 and a plurality of second drainage branch pipes 10;

[0047] Each first drainage branch pipe 2 is laid on the outer wall of the water diversion steel branch pipe 9 and the installation direction of the first drainage branch pipe 2 is consistent with the direction of the corresponding water diversion steel branch pipe 9. The drainage end of the drop down pipe 3 extends into the underground powerhouse 8 of the pumped storage power station. The drop down pipe 3 is respectively connected with the drainage outlet of each first drainage branch pipe 2. The drainage ends of at least three spaced-apart water collecting pipes 1 are respectively connected with a corresponding first drainage branch pipe 2; at least three spaced-apart first drainage branch pipes 2 are connected through the water inlet of a corresponding second drainage branch pipe 10;

[0048] Each water collecting pipe 1 and the corresponding first drainage branch pipe 2 form an inverted T-shaped three-way water pipe structure, and each water collecting pipe 1 extends into the corresponding drilled rock formation borehole channel 7;

[0049] The rock formation drilling channel 7 is used to collect groundwater from the rock formation near the water diversion steel branch pipe 9;

[0050] The water collecting pipe 1 is used to collect groundwater in the rock formation drilling channel 7;

[0051] The first drainage branch pipe 2 is used to collect groundwater from the water collecting pipe 1 connected to the first drainage branch pipe 2;

[0052] The second drainage branch pipe 10 is used to collect groundwater from the first drainage branch pipe 2 which is connected to the second drainage branch pipe 10;

[0053] The drop down pipe 3 is used to collect groundwater in each second drainage branch pipe 10, and to drain the collected groundwater to the drainage channel of the underground powerhouse 8 of the pumped storage power station (i.e. Figure 3 The drainage channel on the lower floor of the factory building 6).

[0054] Preferably, three first drainage branch pipes 2 are arranged in a group at intervals from each other, and the rock formation drainage device may include multiple groups of first drainage branch pipes 2, and each group of first drainage branch pipes 2 is distributed at different positions on the outer wall of the water diversion steel branch pipe 9.

[0055] In this embodiment, the rock drainage device further includes a pressure gauge 4 and a gate valve 5, and the pressure gauge 4 and the gate valve 5 are both connected in series to the drop down pipe 3 extending into the underground powerhouse 8 of the pumped storage power station.

[0056] Specifically, the on-duty personnel can read the reading of the pressure gauge 4 at any time, intuitively monitor the groundwater situation on the upstream side wall of the underground powerhouse, and open the gate valve 5 to relieve the pressure. At the same time, the seepage volume can be measured, thereby ensuring the safety of the underground powerhouse. Such a design has the advantages of simple maintenance and cost saving during operation. Moreover, the pressure gauge 4 and the gate valve 5 at the pipe mouth do not need to be connected to the power supply, and only routine inspections during the operation period are required without adding other costs. In the actual water filling operation stage, through safety inspections during the water filling process, it was found that the reading of the pressure gauge 4 began to rise on the fifth day of water filling, and the gate valve 5 was opened in time to discharge water. The discharge flow rate ranged from 0.02 to 0.155 L / min, which effectively drained the seepage water and ensured that the upstream side wall of the underground powerhouse was dry and free of seepage.

[0057] Furthermore, in this embodiment, the angle range of the tangent of the virtual intersection between the water collecting pipe 1 and the corresponding first drainage branch pipe 2 is 85°-90° (the intersection is the virtual connection center intersection of the water collecting pipe 1 and the corresponding first drainage branch pipe 2); this angle range is beneficial to improving the water collection efficiency of the water collecting pipe 1 for the rock formation.

[0058] Preferably, the optimal value of the angle between the tangent line of the virtual intersection point between the water collecting pipe 1 and the corresponding first drainage branch pipe 2 is 90°.

[0059] Preferably, each first drainage branch pipe 2 is connected to the corresponding second drainage branch pipe 10 at an angle.

[0060] In this embodiment, each first drainage branch pipe 2 is connected to three water collecting pipes 1 .

[0061] In this embodiment, the water collecting pipe 1 is further connected to the corresponding first drainage branch pipe 2 via a tee piece 1b.

[0062] In this embodiment, each rock formation drilling channel 7 is located in the rock formation near the outer wall of the water diversion steel branch pipe 9 above the underground powerhouse 8 of the pumped storage power station.

[0063] In this embodiment, the water collecting pipe 1 is a seamless metal pipe.

[0064] In this embodiment, the gap between the opening of each rock formation drilling channel 7 close to the first drainage branch pipe 2 and the corresponding water collecting pipe 1 is sealed by cement mortar 1c.

[0065] This embodiment provides a construction method for a rock stratum drainage device of an underground powerhouse of a pumped storage power station as described above, comprising the following steps:

[0066] S1, drilling a plurality of rock formation drilling channels 7 at the rock formation position corresponding to the water collecting pipe 1 to be installed, and then executing S2;

[0067] S2, embed each rock formation drilling channel 7 into the water collecting pipe 1 one by one, and then execute S3;

[0068] S3, plugging the gap between the opening of each rock formation drilling channel 7 close to the first drainage branch pipe 2 and the corresponding water collecting pipe 1 with cement mortar 1c, and then executing S4;

[0069] S4, connect the drainage ends of at least three water collecting pipes 1 with the corresponding first drainage branch pipes 2 respectively, connect the second drainage branch pipes 10 with the corresponding drainage ends of at least three spaced-apart water collecting pipes 1 respectively, connect the drainage outlets of at least three spaced-apart second drainage branch pipes 10 with the corresponding drop down pipes 3, and extend the drainage ends of the drop down pipes 3 into the underground plant 8 of the pumped-storage power station.

[0070] Specifically, three rows of rock drilling channels 7 are drilled in the rock with a hand drill, a 1-meter water collecting pipe 1 (specifically a seamless carbon steel pipe) is inserted into each drainage hole, and the seams around the hole are sealed with cement mortar, and the first drainage branch pipe 2 is connected to the water collecting pipe 1 with a tee piece 1b; if there is still seeping groundwater in the area of ​​the water diversion steel branch pipe 9 upstream of the side wall of the underground powerhouse 8 of the pumped-storage power station, the three rows of rock drilling channels 7 can collect the seepage water and guide the seepage water into the water collecting pipe 1; the seepage water upstream of the side wall of the underground powerhouse of the pumped-storage power station is guided through the water collecting pipe 1 to the dischargeable area, that is, the drainage channel of the underground powerhouse 8 of the pumped-storage power station.

[0071] Example 2

[0072] Embodiment 2 is a further optimization of Embodiment 1;

[0073] like Figure 1-Figure 3 As shown:

[0074] This embodiment provides a construction method of a rock stratum drainage device for an underground powerhouse of a pumped storage power station as described in Embodiment 1, comprising the following steps:

[0075] S100, the drainage end of the drop down pipe 3 is arranged in the underground powerhouse 8 of the pumped storage power station, and the pressure gauge 4 and the gate valve 5 are sequentially connected in series to the drop down pipe 3 extending into the underground powerhouse 8 of the pumped storage power station, and then S1 is executed;

[0076] S1, drilling a plurality of rock formation drilling channels 7 at the rock formation position corresponding to the water collecting pipe 1 to be installed, and then executing S2;

[0077] S2, embed each rock formation drilling channel 7 into the water collecting pipe 1 one by one, and then execute S3;

[0078] S3, plugging the gap between the opening of each rock formation drilling channel 7 close to the first drainage branch pipe 2 and the corresponding water collecting pipe 1 with cement mortar 1c, and then executing S4;

[0079] S4, connect the drainage ends of at least three water collecting pipes 1 with the corresponding first drainage branch pipes 2 respectively, connect the second drainage branch pipes 10 with the corresponding drainage ends of at least three spaced-apart water collecting pipes 1 respectively, connect the drainage outlets of at least three spaced-apart second drainage branch pipes 10 with the corresponding drop down pipes 3, and extend the drainage ends of the drop down pipes 3 into the underground plant 8 of the pumped-storage power station.

[0080] Example 3

[0081] Embodiment 3 is a further optimization of Embodiment 1;

[0082] like Figure 1-Figure 3 As shown:

[0083] This embodiment provides a construction method of a rock stratum drainage device for an underground powerhouse of a pumped storage power station as described in Embodiment 1, comprising the following steps:

[0084] S1, drilling a plurality of rock formation drilling channels 7 at the rock formation position corresponding to the water collecting pipe 1 to be installed, and then executing S2;

[0085] S2, embed each rock formation drilling channel 7 into the water collecting pipe 1 one by one, and then execute S3;

[0086] S3, plugging the gap between the opening of each rock formation drilling channel 7 close to the first drainage branch pipe 2 and the corresponding water collecting pipe 1 with cement mortar 1c, and then executing S4;

[0087] S4, respectively connect the drainage ends of at least three water collecting pipes 1 with the corresponding first drainage branch pipes 2, respectively connect the second drainage branch pipes 10 with the corresponding drainage ends of at least three spaced-apart water collecting pipes 1, connect the drainage outlets of at least three spaced-apart second drainage branch pipes 10 with the corresponding drop down pipes 3, extend the drainage ends of the drop down pipes 3 into the underground powerhouse 8 of the pumped storage power station, and then execute S100;

[0088] S100, the drainage end of the drop down pipe 3 is arranged in the underground powerhouse 8 of the pumped storage power station, and the pressure gauge 4 and the gate valve 5 are sequentially connected in series to the drop down pipe 3 extending into the underground powerhouse 8 of the pumped storage power station.

[0089] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A rock stratum drainage device for an underground powerhouse of a pumped storage power station, applied to a rock stratum upstream / above an underground powerhouse (8) of a pumped storage power station, wherein a water diversion steel branch pipe (9) of the pumped storage power station is arranged in the rock stratum, characterized in that: The rock layer drainage device comprises a plurality of drop down pipes (3), a plurality of first drainage branch pipes (2), a plurality of water collecting pipes (1) and a plurality of second drainage branch pipes (10); Each first drainage branch pipe (2) is laid on the outer wall of the water diversion steel branch pipe (9) and the installation direction of the first drainage branch pipe (2) is consistent with the direction of the corresponding water diversion steel branch pipe (9). The drainage end of the drop down pipe (3) extends into the underground powerhouse (8) of the pumped storage power station. The drop down pipe (3) is respectively connected to the drainage outlet of each second drainage branch pipe (10). The drainage ends of at least three spaced-apart water collecting pipes (1) are respectively connected to a corresponding first drainage branch pipe (2); at least three spaced-apart first drainage branch pipes (2) are connected via the water inlet of a corresponding second drainage branch pipe (10); Each water collecting pipe (1) and the corresponding first drainage branch pipe (2) form an inverted T-shaped three-way water pipe structure, and each water collecting pipe (1) extends into a corresponding rock formation borehole channel (7); The rock formation drilling channel (7) is used to collect groundwater from the rock formation near the water diversion steel branch pipe (9); The water collecting pipe (1) is used to collect groundwater in the rock formation drilling channel (7); The first drainage branch pipe (2) is used to collect groundwater from the water collecting pipe (1) connected to the first drainage branch pipe (2); The second drainage branch pipe (10) is used to collect groundwater from the first drainage branch pipe (2) connected to the second drainage branch pipe (10); The drop down pipe (3) is used to collect groundwater in each second drainage branch pipe (10), and to drain the collected groundwater to the drainage channel of the underground powerhouse (8) of the pumped storage power station by means of water level drop drainage; Each rock formation drilling channel (7) is located in a rock formation near the outer wall of a water diversion steel branch pipe (9) above an underground powerhouse (8) of a pumped storage power station; The water collecting pipe (1) is a seamless metal pipe; the gap between the opening of each rock formation drilling channel (7) close to the first drainage branch pipe (2) and the corresponding water collecting pipe (1) is sealed by cement mortar (1c).

2. The rock layer drainage device for the underground powerhouse of a pumped storage power station according to claim 1, characterized in that: The rock layer drainage device also includes a pressure gauge (4) and a gate valve (5), and the pressure gauge (4) and the gate valve (5) are both connected in series to a drop down pipe (3) extending into an underground powerhouse (8) of a pumped storage power station.

3. The rock layer drainage device for the underground powerhouse of a pumped storage power station according to claim 1 or 2, characterized in that: The angle between the tangent line of the virtual intersection point between the water collecting pipe (1) and the corresponding first drainage branch pipe (2) is in the range of 85°-90°.

4. The rock layer drainage device for the underground powerhouse of a pumped storage power station according to claim 1 or 2, characterized in that: Each first drainage branch pipe (2) is connected to three water collecting pipes (1).

5. The rock layer drainage device for the underground powerhouse of a pumped storage power station according to claim 1 or 2, characterized in that: The water collecting pipe (1) is connected to the corresponding first drainage branch pipe (2) via a tee piece (1b).

6. A construction method for a rock stratum drainage device for an underground powerhouse of a pumped storage power station, characterized in that: The following steps are involved: S1, drilling a plurality of rock formation drilling channels (7) at the rock formation positions corresponding to the water collecting pipes (1) to be installed, and then executing S2; S2, embedding the rock formation drilling channels (7) into the water collecting pipe (1) one by one, and then executing S3; S3, plugging the gap between the opening of each rock formation drilling channel (7) close to the first drainage branch pipe (2) and the corresponding water collecting pipe (1) with cement mortar (1c), and then executing S4; S4, connecting the drainage ends of at least three water collecting pipes (1) to the corresponding first drainage branch pipes (2), connecting the second drainage branch pipes (10) to the drainage ends of at least three corresponding first drainage branch pipes (2) spaced apart, connecting the drainage outlets of the second drainage branch pipes (10) to the corresponding drop down pipes (3), at least three second drainage branch pipes (10) are spaced apart, and extending the drainage ends of the drop down pipes (3) into the underground powerhouse (8) of the pumped storage power station; The rock formation drainage device for the underground powerhouse of a pumped storage power station is applied to the rock formation upstream / above the underground powerhouse (8) of the pumped storage power station, in which a water diversion steel branch pipe (9) of the pumped storage power station is arranged, and the rock formation drainage device comprises a plurality of drop down pipes (3), a plurality of first drainage branch pipes (2), a plurality of water collecting pipes (1) and a plurality of second drainage branch pipes (10); Each first drainage branch pipe (2) is laid on the outer wall of the water diversion steel branch pipe (9) and the installation direction of the first drainage branch pipe (2) is consistent with the direction of the corresponding water diversion steel branch pipe (9). The drainage end of the drop down pipe (3) extends into the underground powerhouse (8) of the pumped storage power station. The drop down pipe (3) is respectively connected to the drainage outlet of each second drainage branch pipe (10). The drainage ends of at least three spaced-apart water collecting pipes (1) are respectively connected to a corresponding first drainage branch pipe (2); at least three spaced-apart first drainage branch pipes (2) are connected via the water inlet of a corresponding second drainage branch pipe (10); Each water collecting pipe (1) and the corresponding first drainage branch pipe (2) form an inverted T-shaped three-way water pipe structure, and each water collecting pipe (1) extends into a corresponding rock formation borehole channel (7); The rock formation drilling channel (7) is used to collect groundwater from the rock formation near the water diversion steel branch pipe (9); The water collecting pipe (1) is used to collect groundwater in the rock formation drilling channel (7); The first drainage branch pipe (2) is used to collect groundwater from the water collecting pipe (1) connected to the first drainage branch pipe (2); The second drainage branch pipe (10) is used to collect groundwater from the first drainage branch pipe (2) connected to the second drainage branch pipe (10); The drop down pipe (3) is used to collect groundwater in each second drainage branch pipe (10), and to drain the collected groundwater to the drainage channel of the underground powerhouse (8) of the pumped storage power station by means of water level drop drainage.

7. The construction method of the rock stratum drainage device of the underground powerhouse of a pumped storage power station according to claim 6, characterized in that: Before S1 or after S4, the method further includes S100: S100, the drainage end of the drop down pipe (3) is arranged in the underground powerhouse (8) of the pumped storage power station, and the pressure gauge (4) and the gate valve (5) are sequentially connected in series to the drop down pipe (3) extending into the underground powerhouse (8) of the pumped storage power station; Each of the rock formation drilling channels (7) is located in the rock formation near the outer wall of the water diversion steel branch pipe (9) above the underground powerhouse (8) of the pumped storage power station; The water collecting pipe (1) is a seamless metal pipe; The gap between the opening of each rock formation drilling channel (7) close to the first drainage branch pipe (2) and the corresponding water collecting pipe (1) is sealed with cement mortar (1c); The rock layer drainage device also includes a pressure gauge (4) and a gate valve (5), and the pressure gauge (4) and the gate valve (5) are both connected in series to a drop down pipe (3) extending into an underground powerhouse (8) of a pumped storage power station; The angle between the tangent line of the virtual intersection of the water collecting pipe (1) and the corresponding first drainage branch pipe (2) is in the range of 85°-90°; Each of the first drainage branch pipes (2) is connected to three water collecting pipes (1); The water collecting pipe (1) is connected to the corresponding first drainage branch pipe (2) via a tee piece (1b).

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