Water intake structure for underwater rock plug blasting

Abstract

A water intake structure for underwater rock plug blasting comprises a slag collecting pit, the slag collecting pit comprises a slag collecting section, an inlet section and a transition section, the inlet section and the transition section are located at the two ends of the slag collecting section respectively, a rock plug is arranged at the end, away from the transition section, of the inlet section, and an inflation inlet is formed in the position, close to the rock plug, of the upper side of the inlet section. The air inflation opening is formed in the position, close to the rock plug, of the upper side of the inlet section, water is injected into the slag collecting pit before the rock plug is blasted, and after water injection is completed, air can be inflated into the slag collecting pit through the air inflation opening, so that the air pressure in the air cushion chamber is adjusted. Due to the fact that the air pressure in the air cushion chamber is increased, blasting impact towards the interior of the slag collecting pit can be relieved during blasting, and therefore blasting rock ballast can be effectively prevented from rushing out of the slag collecting pit and entering the diversion tunnel section.

Description

Technical Field

[0001] The utility model relates to the technical field of underwater rock plug blasting, in particular to a water intake structure used for underwater rock plug blasting. Background Art

[0002] As a special design and construction scheme, underwater rock plug blasting is to reserve a certain thickness of rock mass (i.e. rock plug) after the excavation of the water diversion tunnel is completed. After the downstream tunnel is completed, the reserved rock plug is blasted away at one time to connect the water diversion tunnel with the reservoir area. Underwater rock plug blasting has many influencing factors and is at the throat of the entire water diversion project. The success or failure of its blasting determines the success or failure of the entire water diversion project.

[0003] Chinese patent document CN115979084A, publication (announcement) date: 2023.04.18, discloses a method for underwater rock plug blasting in a tunnel waterway. This method is a commonly used method at present. Its advantages are: by forming an air cushion chamber at the top of the tunnel, blasting is carried out under the action of the air cushion chamber, and the blasting slag produced by the blasting is contained in the slag collection pit; its disadvantage is that: the air pressure in the air cushion chamber cannot be actively adjusted to increase, and during blasting, some blasting slag will rush out of the slag collection pit and enter the water diversion tunnel section. Utility Model Content

[0004] The utility model aims to provide a water intake structure for underwater rock plug blasting. By arranging an air filling port at a position close to the rock plug on the upper side of the inlet section, air can be filled into the slag collecting pit through the air filling port, thereby adjusting the air pressure in the air cushion chamber.

[0005] To achieve the above-mentioned purpose, the utility model provides a water intake structure for underwater rock plug blasting, including a slag collection pit, the slag collection pit includes a slag collection section, an inlet section and a gradient section, the inlet section and the gradient section are respectively located at the two ends of the slag collection section, the inlet section is provided with a rock plug at the end away from the gradient section, and an inflation port is provided on the upper side of the inlet section at a position close to the rock plug.

[0006] The water intake structure also includes a water diversion tunnel section and a gate well. An inflation pipe is arranged in the lining of the inlet section, slag gathering section, gradient section, water diversion tunnel section and gate well. One end of the inflation pipe is connected to the inflation port, and the other end extends out of the gate well.

[0007] The included angle between the center line of the rock plug and the horizontal line is 40°~50°.

[0008] The bottom of the gradient section is provided with a slag retaining pier at one end away from the inlet section.

[0009] At least one grouting hole is arranged on the lining top of the slag collection pit.

[0010] Water-stop copper sheets are installed between the slag gathering section and the inlet section, and between the slag gathering section and the gradient section.

[0011] The downstream end of the gate well is provided with a delivery pipeline, and a plug is arranged in the delivery pipeline during rock plug blasting.

[0012] Compared with the prior art, the utility model has the following technical effects:

[0013] The utility model provides an air filling port at the upper side of the inlet section near the rock plug, and water is injected into the slag collection pit before the rock plug is blasted. After the water injection is completed, air can be inflated into the slag collection pit through the air filling port, thereby adjusting the air pressure in the air cushion chamber. As the air pressure in the air cushion chamber increases, the blasting impact into the slag collection pit will be slowed down during blasting, thereby effectively preventing the blasting slag from rushing out of the slag collection pit and entering the water diversion tunnel section. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0015] Figure 1 It is a schematic cross-sectional view of the water intake structure of the utility model.

[0016] Figure 2 It is a schematic diagram of the cross-sectional structure of the slag collecting pit of the utility model.

[0017] Figure 3 for Figure 1 Schematic diagram of the AA section structure.

[0018] In the figure:

[0019] Slag collecting pit 10, grouting hole 101, water-stop copper sheet 102, slag collecting section 11, inlet section 12, gradient section 13, slag retaining pier 131, rock plug 20, center line 21, horizontal line 22, inflation port 30, inflation pipe 31, water diversion tunnel section 40, gate shaft 50, conveying pipe 60, plug 61. DETAILED DESCRIPTION

[0020] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0021] See also Figure 1-3A water intake structure for underwater rock plug blasting includes a slag collection pit 10, wherein the slag collection pit 10 includes a slag collection section 11, an inlet section 12 and a gradient section 13, wherein the inlet section 12 and the gradient section 13 are respectively located at two ends of the slag collection section 11, and a rock plug 20 is provided at one end of the inlet section 12 away from the gradient section 13, and an inflation port 30 is provided on the upper side of the inlet section 12 at a position close to the rock plug 20.

[0022] By setting an inflation port 30 at a position close to the rock plug 20 on the upper side of the inlet section 12, water is injected into the slag collecting pit 10 before the rock plug is blasted. After the water injection is completed, air can be inflated into the slag collecting pit 10 through the inflation port 30 to adjust the air pressure in the air cushion chamber.

[0023] As the air pressure in the air cushion chamber increases, during blasting, the blasting impact into the slag pit 10 will be slowed down, thereby effectively preventing the blasting slag from rushing out of the slag pit and entering the water diversion tunnel section. At the same time, the air cushion chamber also creates dry land conditions for detonation.

[0024] Specifically, the water intake structure also includes a water diversion tunnel section 40 and a gate well 50. An inflation pipe 31 is arranged in the lining of the inlet section 12, the slag gathering section 11, the gradient section 13, the water diversion tunnel section 40 and the gate well 50. One end of the inflation pipe 31 is connected to the inflation port 30, and the other end extends out of the gate well 50.

[0025] A Φ100 PVC inflation pipe is pre-buried on the top of the lining to connect the inflation port 30 with the top platform of the gate well 50. After the water filling is completed, air is inflated into the inlet section 12 through the inflation pipe 31 to form a pressurized air cushion chamber cavity.

[0026] The included angle between the center line 21 of the rock plug 20 and the horizontal line 22 is 40° to 50°, and by controlling the blasting impact direction, the blasting slag enters the slag gathering section 11. In this embodiment, the included angle is preferably 45°.

[0027] See also Figure 1 The bottom of the gradient section 13 is provided with a slag blocking pier 131 at one end away from the inlet section 12, further preventing blasting slag from entering the water diversion tunnel section 40. It can also be used to block mud and sand during later operation.

[0028] See also Figure 3 At least one grouting hole 101 is provided on the top of the lining of the slag collection pit 10. It is convenient to grout and fill the space between the outer wall of the slag collection pit 10 and the rock mass through the grouting hole 101 to prevent water from entering the outer wall of the slag collection pit 10 and causing water gushing accidents after the rock plug 20 is blasted.

[0029] Since the slag collecting pit 10 is cast in sections, in order to prevent leakage at the joints, water-stopping copper sheets 102 are installed between the slag collecting section 11 and the inlet section 12 , and between the slag collecting section 11 and the gradient section 13 .

[0030] See also Figure 1 In order to prevent the valve in the gate well 50 from being damaged during blasting, a plug 61 is provided in the delivery pipe 60 during rock plug blasting. The delivery pipe 60 is closed by the plug 61. The plug 61 is cast with concrete. After the blasting is completed, the valve in the gate well 50 is closed, the water in the delivery pipe 60 is pumped out, and the plug 61 is removed.

[0031] In a water diversion project, the water intake tunnel from the inlet control gate to the upstream is the gate well 50, the diversion tunnel section 40, the slag pit 10 and the rock plug. The gate well 50 has a rectangular excavation section of 6.6m×11m (width×length) and a depth of 85m; the diversion tunnel section 40 is a semicircular gate hole, 132.6m long, with a typical excavation section of 5.4m×6.1m (width×height), and a lining section of 4.0m×4.0m (width×height). The slag pit 10 is a semicircular gate hole type, with a typical excavation section of 7.0m×14.0m (width×height), a lining section of 4.8m×12.0m (width×height), and a length of 38.7m. The diversion tunnel section 40 enters from the gate well 50, with a length of 132.6m, including a horizontal section of 11m, an inclined section of 121.6m, and a bottom slope of 7%.

[0032] According to the topographic and geological conditions of the slope at the rock plug, and considering that the blasting slag of the rock plug body and the rocks dropped during operation can flow smoothly down to the slag gathering section 11, the angle between the center line of the rock plug and the horizontal line 22 is determined to be 45°.

[0033] In this embodiment, the slope of the bottom of the inlet section 12 is 1:0.5, and the slope of the top of the inlet section 12 is 1:1.16.

[0034] The working principle or action process of the utility model is as follows:

[0035] Before the rock plug is blasted, water is filled into the slag collecting pit 10, and an air compressor is connected to the inflation pipe 31. A valve is also provided on the inflation pipe 31. The valve is opened and air is inflated into the slag collecting pit 10 through the air compressor to form a pressurized air cushion chamber (air bag) between the bottom of the rock plug and the slag collecting pit. When the rock plug is blasted, the bottom of the rock plug is separated from the downstream water body. During blasting, the pressurized air cushion chamber can slow down the blasting impact into the slag collecting pit 10, thereby effectively preventing the blasting slag from rushing out of the slag collecting pit and entering the water diversion tunnel section.

Claims

1. A water intake structure for underwater rock plug blasting, comprising a slag collection pit (10), characterized in that: The slag collection pit (10) comprises a slag gathering section (11), an inlet section (12) and a gradient section (13); the inlet section (12) and the gradient section (13) are respectively located at two ends of the slag gathering section (11); a rock plug (20) is provided at one end of the inlet section (12) away from the gradient section (13); and an air filling port (30) is provided on the upper side of the inlet section (12) at a position close to the rock plug (20).

2. The water intake structure for underwater rock plug blasting according to claim 1, characterized in that: The water intake structure further comprises a water diversion tunnel section (40) and a gate well (50); an air charging pipe (31) is arranged in the lining of the inlet section (12), the slag gathering section (11), the gradient section (13), the water diversion tunnel section (40) and the gate well (50); one end of the air charging pipe (31) is connected to the air charging port (30), and the other end extends out of the gate well (50).

3. The water intake structure for underwater rock plug blasting according to claim 1, characterized in that: The included angle between the center line (21) of the rock plug (20) and the horizontal line (22) is between 40° and 50°.

4. The water intake structure for underwater rock plug blasting according to claim 1, characterized in that: A slag retaining pier (131) is provided at the bottom of the gradient section (13) at an end away from the inlet section (12).

5. The water intake structure for underwater rock plug blasting according to claim 1, characterized in that: At least one grouting hole (101) is provided on the top of the lining of the slag collection pit (10).

6. The water intake structure for underwater rock plug blasting according to claim 1, characterized in that: A water-stop copper sheet (102) is installed between the slag gathering section (11) and the inlet section (12), and between the slag gathering section (11) and the gradient section (13).

7. The water intake structure for underwater rock plug blasting according to claim 2, characterized in that: The downstream end of the gate well (50) is provided with a delivery pipeline (60). When the rock plug is blasted, a plug (61) is arranged in the delivery pipeline (60).

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