Pressure relief device for reducing water pressure outside underground cavern

Abstract

The invention discloses a pressure relief device for reducing water pressure outside an underground cavern. The pressure relief device comprises an outer cylinder, a steel base plate, a hinge, a spring and a bottom plate. The outer cylinder and the steel base plate are pre-buried in the reinforced concrete lining, the steel base plate is located on the outer edge of the open end of the outer cylinder, the two hinges are symmetrically installed in the outer cylinder through the springs, the bottom plate is fixedly connected with the steel base plate, and the drainage hole is formed in the bottom plate. The two hinges divide the interior of the outer barrel into an upper closed part and a lower closed part under the combined action of inner water pressure, outer water pressure and spring tension, when the inner water pressure difference and the outer water pressure difference are larger than the starting pressure difference set between the hinges, the device is started, and the spring is stretched; outer water enters from the upper end of the outer cylinder and then is discharged into the reinforced concrete lining through the water outlet holes through the gaps between the hinges, the hinges are reset and the device returns to the closed state along with the discharging of the outer water, the pressure difference is reduced, the spring contracts to enable the device to return to the closed state, different device starting pressure differences are set by adjusting the initial stretching amount of the spring, and the inner and outer water pressure difference is accurately controlled.

Description

Technical Field

[0001] The invention relates to the field of engineering technology, and in particular to a pressure relief device for reducing the water pressure outside an underground cave. Background Art

[0002] Cavern structures buried deep underground are usually lined with reinforced concrete. Due to the presence of groundwater in the rock strata, especially in areas with deep caverns and high groundwater levels, the stress on the lining structure is mainly determined by the external water pressure acting on the outside of the structure. Excessive external water pressure will lead to a significant increase in the amount of lining concrete and structural steel bars, which will not only increase project investment, but also pose challenges to the safety of the structure.

[0003] At present, the commonly used methods for dealing with high external water pressure in deep-buried caverns are consolidation grouting of the rock layers around the surrounding rock and setting shallow drainage holes on the concrete lining. Through the consolidation grouting of the surrounding rock, the surrounding rock can better share the load acting on the lining structure, and the external water head can be effectively reduced by setting drainage holes. The combined use of these two treatment methods is effective in dealing with high external water pressure outside the lining. However, for some underground caverns with special functions, such as hydraulic tunnels and surge chambers, setting shallow drainage holes poses the risk of internal water seepage, causing water loss and affecting project benefits. At the same time, due to the requirements of ecological and environmental protection, excessive discharge of external water pressure will lead to a series of ecological and environmental problems. At present, there are also some devices and structures that can drain external water, but the discharge volume is difficult to control, installation and disassembly are inconvenient, installation and disassembly damage the concrete structure, and occupy the cavern section. Summary of the invention

[0004] In view of this, the present invention provides a pressure relief device for reducing the external water pressure of an underground cavern. When the external water pressure is too high, the device automatically starts and the external water is discharged into the cavern, thereby achieving the purpose of reducing the external water pressure and controlling the external water discharge volume.

[0005] A pressure relief device for reducing the water pressure outside an underground cavern, comprising an outer cylinder, a steel pad, a hinge, a spring and a bottom plate;

[0006] One end of the outer tube is closed while the other end is open, and a drainage hole is provided on the closed end; the outer tube and the steel pad are pre-buried inside the reinforced concrete lining, and the steel pad is located at the outer edge of the open end of the outer tube;

[0007] Two hinges are symmetrically installed inside the outer tube, two ends of the spring are connected to the inner wall of the outer tube and the upper surface of the hinge respectively, the bottom plate is installed at the bottom of the outer tube to close the open end, the bottom plate is fixedly connected to the steel pad, and a drainage hole is arranged on the bottom plate; the upper and lower surfaces of the hinge bear the external water pressure and the internal water pressure respectively, and the two hinges separate the inside of the outer tube into two closed upper and lower parts under the joint action of the internal water pressure, the external water pressure and the spring tension. When the pressure difference between the inside and outside water is greater than the starting pressure difference set between the hinges, the device starts, the spring stretches, and the external water enters from the upper end of the outer tube and is discharged into the reinforced concrete lining from the water outlet through the gap between the hinges. As the external water is discharged, the pressure difference decreases, the spring contracts to reset the hinge, and the device returns to the initial closed state. By adjusting the initial stretching amount of the spring to set different device starting pressure differences, the internal and external water pressure differences are precisely controlled.

[0008] Furthermore, a water stop strip is provided at the end of each hinge, and the two hinges are sealed watertightly by the water stop strip.

[0009] Furthermore, the gap between the pressure relief device and the reinforced concrete lining excavation surface is filled with filter material.

[0010] Furthermore, the hinge end is bent upward at an angle so that when the two hinge end surfaces are completely in contact with each other to achieve a closed state, the contact surface remains perpendicular to the horizontal plane.

[0011] Furthermore, the outer cylinder, hinge, bottom plate and steel backing plate are made of stainless steel or other materials with good durability and strength that meet requirements.

[0012] Beneficial effects:

[0013] 1. The present invention sets a pressure relief device in the reinforced concrete lining. When the external water of the lining exceeds the preset pressure difference, the hinge downward flipping device is activated, and the external water is discharged into the tunnel. As the external water is discharged, the pressure difference decreases, the spring stretches, the hinge is flipped up and reset, and the device returns to the initial closed state, which can effectively prevent the internal water from seeping out. At the same time, different device starting pressure differences can be set by adjusting the initial stretching amount of the spring, so as to achieve precise control of the device starting pressure, effectively solving the problem of external water discharge and prevention of internal water seepage under high external water pressure in deep underground tunnels.

[0014] 2. The bottom plate of the present invention is installed close to the bottom of the outer tube and is connected and fixed to the steel pad pre-buried in the reinforced concrete lining by bolts, which can prevent the bottom plate from falling during operation and does not occupy the cross section of the cavern.

[0015] 3. The present invention provides a water stop strip at the end of the hinge. After installation, the two hinges are sealed by the water stop strip, which can prevent the internal water from seeping out and the external water from being discharged excessively.

[0016] 4. The pressure relief device of the present invention is divided into an independent outer cylinder and an internal structure. The internal structure can be installed, repaired and replaced separately, reducing the difficulty and economic cost of replacement. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the installation of the device of the present invention;

[0018] Figure 2 is a cross-sectional view of the device of the present invention (initial state);

[0019] Figure 3 is a cross-sectional view of the device of the present invention (start-up state);

[0020] Figure 4 It is a cross-sectional view of the outer cylinder in the present invention;

[0021] Figure 5 It is a cross-sectional view (AA) of the initial state of the device of the present invention;

[0022] Figure 6 It is a side view of the hinge of the device of the present invention;

[0023] Figure 7 This is a hinge expansion diagram of the device of the present invention;

[0024] Figure 8 A top view of the bottom plate of the device of the present invention;

[0025] Fig. 9 It is a top view of the steel pad of the device of the present invention;

[0026] Fig.10 This is a large-scale drawing of the connection between the bottom plate and the steel backing plate of the device of the present invention;

[0027] Fig.11 It is a schematic diagram of the length of the spring in different states in the present invention.

[0028] Among them, 1-reinforced concrete lining, 2-outer tube, 3-drainage hole, 4-hinge, 401-water stop strip, 5-bolt, 6-spring, 7-bottom plate, 8-drainage hole, 9-steel pad, 10-bolt, 11-lining stress steel bar, 12-filter material. DETAILED DESCRIPTION

[0029] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0030] The present invention provides a pressure relief device for reducing the water pressure outside the underground cavern. Figure 1 As shown, the reinforced concrete lining 1 is buried in the surrounding rock, the annular space inside the reinforced concrete lining 1 is the tunnel, the pressure relief device of the present invention is arranged on the reinforced concrete lining 1, and the reinforced concrete lining 1 bears the internal and external water pressures P1 and P2.

[0031] As attached Figure 2 and 3 As shown in FIG. 1 , the pressure relief device includes an outer cylinder 2, a steel backing plate 9, a hinge 4, a spring 6, a filter material 12 and a bottom plate 7. Figure 4 As shown, the outer cylinder 2 is a rectangular structure as a whole, with a closed upper end and an open lower end, and a drainage hole 3 is provided on the closed end.

[0032] When pouring reinforced concrete lining 1, the outer tube 2 and steel plate 9 are pre-buried. Fig.10 As shown, the steel plate 9 is welded to the lining stress-bearing steel bars 11 and fixed in the concrete lining 1 . The steel plate 9 is located at the outer edge of the open end of the outer tube 2 .

[0033] Two hinges 4 are symmetrically installed inside the outer tube 2, two ends of the spring 6 are connected to the inner wall of the outer tube 2 and the upper surface of the hinge 4 respectively, the bottom plate 7 is installed at the bottom of the outer tube to close the open end, the bottom plate 7 is fixedly connected to the steel pad 9, and a drainage hole 8 is arranged on the bottom plate; the upper and lower surfaces of the hinge 4 bear the external water pressure and the internal water pressure respectively, and the two hinges 4 separate the interior of the outer tube 2 into two closed upper and lower parts under the joint action of the internal water pressure, the external water pressure and the tension of the spring 6, the drainage holes 3 on the top plate of the outer tube 2 and the drainage holes 8 on the bottom plate 7 ensure that the internal water and the external water can flow freely and act on the hinge 4; the gap between the device and the excavation surface is filled with anti-filter material 12 to avoid clogging of the device. When the pressure difference between the internal and external water is greater than the starting pressure difference set between the hinges, the device starts, the spring 6 stretches, and the external water enters from the upper end of the outer tube 2 and is discharged into the reinforced concrete lining 1 through the gap between the hinges 4 from the water outlet. As the external water is discharged, the pressure difference decreases, the spring 6 contracts, and the hinge 4 is reset, and the device returns to the initial closed state. By adjusting the initial stretching amount of the spring 6 to set different starting pressure differences of the device, the internal and external water pressure difference can be accurately controlled.

[0034] The outer tube 2, hinge 4, bottom plate 7, and steel pad 9 are made of stainless steel or other materials with good durability and strength that meet the requirements. In order to avoid safety accidents caused by the bottom plate 7 falling during normal operation, the outer tube 2 and steel pad 9 need to be pre-buried when pouring the reinforced concrete lining 1. The steel pad 9 is welded and connected to the lining stress steel bar 11 to ensure the stability of the steel pad 9. After the outer tube 2 and the steel pad 9 are installed, the hinge 4, spring 6, and bottom plate 7 can be installed in sequence. It should be noted that one end of the spring 6 is connected to the outer wall of the outer tube 2, and the other end is connected to the hinge 4. The bottom plate 7 is installed close to the bottom of the outer tube 2, and the bottom plate 7 is connected to the steel pad 9 by bolts 10, which ensures that the outer tube 2 and the bottom plate 7 are fixed in the concrete lining 1.

[0035] During normal operation, the upper part of the device is connected to the external water, and the lower part is connected to the internal water. Therefore, the hinge 4 is subjected to the internal water pressure P1 and the external water pressure P2 at the same time. The internal and external water pressure difference ΔP1 = P2-P1. Since one end of the spring 6 is connected to the outer wall of the outer tube 2 and the other end is connected to the hinge 4, the pressure difference on the hinge 4 is transmitted to the spring 6, and the pressure difference decomposed to the axial direction of the spring 6 is ΔP2.

[0036] ① When the internal water pressure P1 is greater than the external water pressure P2 and ΔP2 is less than the set device startup pressure difference P, the hinge 4 is closed and the water stop strip 401 is sealed to stop water and prevent the internal water from seeping out; ② When ΔP2 is greater than or equal to the set device startup pressure difference P, the hinge 4 rotates downward, the spring 6 is stretched, and the external water is discharged into the cave through the gap between the two hinges and the drainage hole 8 on the bottom plate 7. As the groundwater is discharged, the external water pressure P2 gradually decreases. When the condition of ① is met, the hinge 4 rotates upward, the water stop strip 401 is sealed to stop water, and the device returns to its initial state.

[0037] The initial stretched length of spring 6 is The initial extension of the spring can be adjusted to set different device starting pressure differences P for precise control.

[0038] After draining the water, the equipment can be inspected and replaced. The hinge 4, spring 6 and bottom plate 7 are independent parts, which can be installed, repaired and replaced in part or in whole. The replacement is convenient without damaging the original lining concrete structure, which reduces the difficulty and economic cost of replacement.

[0039] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A pressure relief device for reducing the water pressure outside an underground cavern, characterized in that: It includes an outer cylinder, a steel backing plate, a hinge, a spring and a bottom plate; One end of the outer tube is closed while the other end is open, and a drainage hole is provided on the closed end; the outer tube and the steel pad are pre-buried inside the reinforced concrete lining, and the steel pad is located at the outer edge of the open end of the outer tube; Two hinges are symmetrically installed inside the outer tube, two ends of the spring are connected to the inner wall of the outer tube and the upper surface of the hinge respectively, the bottom plate is installed at the bottom of the outer tube to close the open end, the bottom plate is fixedly connected to the steel pad, and a drainage hole is arranged on the bottom plate; the upper and lower surfaces of the hinge bear the external water pressure and the internal water pressure respectively, and the two hinges separate the inside of the outer tube into two closed upper and lower parts under the joint action of the internal water pressure, the external water pressure and the spring tension. When the pressure difference between the inside and outside water is greater than the starting pressure difference set between the hinges, the device starts, the spring stretches, and the external water enters from the upper end of the outer tube and is discharged into the reinforced concrete lining from the water outlet through the gap between the hinges. As the external water is discharged, the pressure difference decreases, the spring contracts to reset the hinge, and the device returns to the initial closed state. By adjusting the initial stretching amount of the spring to set different device starting pressure differences, the internal and external water pressure differences are precisely controlled.

2. The pressure relief device for reducing the water pressure outside the underground cave as claimed in claim 1, characterized in that: A water stop strip is arranged at the end of each hinge, and the two hinges are sealed by the water stop strip.

3. The pressure relief device for reducing the water pressure outside the underground cave as claimed in claim 2, characterized in that: The gap between the pressure relief device and the reinforced concrete lining excavation surface is filled with filter material.

4. The pressure relief device for reducing the water pressure outside the underground cave as claimed in claim 3, characterized in that: The hinge end is bent upward at an angle so that when the two hinge end surfaces are completely in contact with each other to achieve a closed state, the contact surface remains perpendicular to the horizontal plane.

5. The pressure relief device for reducing the water pressure outside the underground cave as claimed in claim 3 or 4, characterized in that: The outer cylinder, hinge, bottom plate and steel pad are made of stainless steel metal material.

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