Wading underground cavern pressure difference control device based on double-layer outer cylinder

Abstract

The invention discloses a wading underground cavern pressure difference control device based on a double-layer outer barrel. The wading underground cavern pressure difference control device comprises a valve body outer barrel, a piston, a spring and a bottom plate. The valve body outer cylinder is of a double-layer structure, an annular gap is formed in the upper end of the valve body outer cylinder, a water outlet hole is machined in the lower end of the valve body outer cylinder, the valve body outer cylinder is embedded in a reinforced concrete lining, the piston and the spring are sequentially installed in the valve body outer cylinder, and the two ends of the spring are connected with the piston and the bottom plate respectively. When the pressure difference between the inside water and the outside water is larger than the starting pressure difference set by the piston, the device is started, the spring is compressed, the outside water is discharged into the reinforced concrete lining from the water outlet through the annular gap of the outer cylinder of the valve body, the pressure difference is reduced along with discharging of the outside water, the spring extends, the piston moves upwards and then resets, and the device returns to the initial state. Different device starting pressure differences are set by adjusting the initial compression amount of the spring, internal water leakage can be effectively prevented, and meanwhile the internal and external water pressure difference can be accurately controlled.

Description

Technical Field

[0001] The invention relates to the field of engineering technology, and in particular to a water-wading underground cavern pressure difference control device based on a double-layer outer cylinder. Background Art

[0002] High external water pressure is one of the problems often encountered in the design and construction of deep-buried water-related caverns. When the external water pressure is too high, the force of the cavern lining structure is mainly determined by the external water pressure it bears. High external water pressure often leads to excessive thickness of the cavern lining and increased use of steel bars, which not only increases the project investment, but also fails to ensure the safety and stability of the lining structure. To solve this problem, the project usually adopts the method of surrounding rock consolidation grouting and setting shallow drainage holes on the lining. The surrounding rock is reinforced by consolidation grouting, the integrity of the surrounding rock is improved, and the surrounding rock shares more external water pressure. At the same time, the external water pressure acting on the lining is released in conjunction with shallow drainage holes. For most water-related caverns, this method can have a significant effect, but for underground caverns with special functions, such as hydraulic tunnels, surge tanks, etc., directly drilling drainage holes on the lining to reduce the external water pressure will cause the problem of internal water seepage, resulting in water loss and affecting the project benefits. At the same time, for long-distance tunnels that pass through complex geological conditions, the distribution of groundwater cannot be surveyed in detail. Although conventional seepage and drainage measures can remove external water and reduce external water pressure, excessive external water discharge will cause a sharp drop in groundwater levels, bringing about a series of ecological and environmental problems. Based on the above analysis, conventional underground water-related cavern seepage and drainage systems mainly have the following problems:

[0003] First, the seepage and drainage system cannot prevent internal water from seeping out; second, it cannot accurately control the pressure difference between internal and external water, which either leads to excessive discharge of external water and causes ecological and environmental problems, or causes structural safety problems due to the inability to discharge external water; third, the seepage and drainage structure is consolidated with the concrete lining, making it difficult to repair and replace. Summary of the invention

[0004] In view of this, the present invention provides a pressure difference control device for a water-related underground cavern based on a double-layer outer tube. When the external water pressure is lower than the internal water pressure, it can effectively prevent the internal water from seeping out. When the external water pressure exceeds the set value, the pressure difference control device can discharge the external water into the tunnel, thereby achieving the purpose of reducing the external water pressure. At the same time, the pressure difference between the internal and external water can be accurately controlled.

[0005] A pressure difference control device for a water-carrying underground cavern based on a double-layer outer cylinder, comprising a valve body outer cylinder, a piston, a spring and a bottom plate;

[0006] The outer shape of the valve body outer cylinder is composed of two cylindrical sections with different diameters. The large-diameter cylindrical section is a double-layer structure with both ends open. One end of the large-diameter cylindrical section forms an annular gap through the height difference between the inner and outer double-layer structures. A water outlet hole is processed on the bottom surface of the other end of the large-diameter cylindrical section. The small-diameter cylindrical section is a single-layer structure, and the front end of the small-diameter cylindrical section has a stop structure.

[0007] The valve body outer cylinder is buried in the reinforced concrete lining, and the piston and spring are sequentially installed into the interior of the valve body outer cylinder from the lower end of the valve body outer cylinder, and the two ends of the spring are respectively connected to the piston and the bottom plate, and the bottom plate is fixedly connected to the lower end of the valve body outer cylinder to close the open end and pre-tighten the spring at the same time. The pre-tightening force of the spring acts on the piston and makes the upper end of the piston cooperate with the stop structure to close the open end above the valve body outer cylinder; the piston is subjected to the action of internal water pressure and external water pressure at the same time. When the internal and external water pressure difference is greater than the starting pressure difference set by the piston, the device is started, the spring is compressed, and external water enters from the upper end of the valve body outer cylinder and is discharged into the interior of the reinforced concrete lining from the water outlet through the annular gap. As the external water is discharged, the pressure difference decreases, the spring stretches, the piston moves up and then resets, and the device returns to the initial state. Different device starting pressure differences are set by adjusting the initial compression amount of the spring to accurately control the internal and external water pressure differences.

[0008] Furthermore, the outer tube of the valve body includes an outer wall, an inner wall and a connecting plate. The outer wall and the bottom of the inner wall are connected into one by the connecting plate. The height difference between the outer wall and the inner wall forms an annular gap-shaped water outlet, and a water outlet hole is processed on the connecting plate.

[0009] Furthermore, the bottom of the pressure difference control device is arranged flush with the inner wall of the reinforced concrete lining, and the gap between the pressure difference control device and the excavation surface of the reinforced concrete lining is filled with filter material.

[0010] Furthermore, the piston is composed of a piston body and a water stop strip, and the water stop strip is embedded in the top of the piston body and at a position corresponding to the stop of the outer cylinder of the valve body.

[0011] Furthermore, the piston body is composed of a sealing part and a supporting part. The middle section of the sealing part adopts an inwardly concave structure, and the disc structures at the upper and lower ends cooperate with the inner wall of the outer tube of the valve body to achieve sealing. The supporting part is located below the sealing part, and the supporting part is used to fit the spring.

[0012] Beneficial effects:

[0013] 1. The present invention arranges a pressure difference control device in the reinforced concrete lining. When the water outside the lining exceeds a preset pressure difference, the device starts and the external water is discharged into the tunnel. As the external water is discharged, the pressure difference decreases, the spring stretches, the piston moves up and resets, and the device returns to its 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 compression amount of the spring, so as to achieve precise control of the device starting pressure, effectively solving the problem of discharging external water and preventing internal water from seeping out under high external water pressure in deep underground tunnels.

[0014] 2. The outer cylinder of the valve body of the present invention adopts an inner and outer double-layer structure. After the external water is discharged, it is discharged into the reinforced concrete lining through the annular gap and the water outlet hole. During this process, the external water does not contact the spring in the device, avoiding the corrosion caused by the long-term contact between the spring and water, and effectively extending the replacement cycle of parts and the service life of the device.

[0015] 3. The structure of the present invention is divided into an independent outer cylinder and an internal structure (spring and piston). The internal structure can be installed, repaired and replaced separately, which is easy to operate and has low maintenance costs. When replacing and repairing, it only requires dismantling the bottom plate, which is convenient to replace and does not damage the lining concrete structure.

[0016] 4. The piston body of the present invention is composed of a sealing part and a supporting part. The middle section of the sealing part adopts a concave structure, and the disc structures at the upper and lower ends cooperate with the inner wall of the outer tube of the valve body to achieve sealing. The concave structure can reduce the contact area between the piston and the inner wall and reduce the friction resistance, so that the starting pressure difference of the device can be controlled more accurately. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0019] Figure 3 It is a cross-sectional view of the pressure difference control device of the present invention (starting state);

[0020] Figure 4 A top view of the pressure difference control device of the present invention;

[0021] Figure 5 It is a cross-sectional view of the outer cylinder of the valve body in the differential pressure control device of the present invention;

[0022] Figure 6 It is a cross-sectional view of the piston and spring in the pressure difference control device of the present invention.

[0023] Among them, 1-reinforced concrete lining, 2-valve body outer cylinder, 2-1-outer wall, 2-2-inner wall, 2-3-connecting plate, 2-4-water outlet, 3-piston, 3-1-piston body, 3-2-water stop strip, 4-spring, 5-bottom plate, 6-filter material. DETAILED DESCRIPTION

[0024] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0025] The present invention provides a pressure difference control device for a water-carrying underground cavern based on a double-layer outer cylinder, as shown in the attached Figure 1As shown, the reinforced concrete lining 1 is buried inside the surrounding rock mass, and the annular space inside the reinforced concrete lining 1 is the tunnel. The pressure difference control device of the present invention is arranged on the reinforced concrete lining 1, and the reinforced concrete lining 1 is subjected to internal and external water pressures P1 and P2.

[0026] As attached Figure 2 As shown, the pressure difference control device includes a valve body outer cylinder 2, a piston 3, a spring 4, a bottom plate 5 and an anti-filter material 6. The valve body outer cylinder 2 is buried in the reinforced concrete lining 1 and is closely connected to the reinforced concrete lining 1. The piston 3 is installed inside the valve body outer cylinder 2, and the piston 3 can move up and down after being subjected to force. One end of the spring 4 is connected to the piston 3, and the other end is connected to the bottom plate 5. The bottom plate 5 is connected and fixed to the bottom of the valve body outer cylinder 2 by bolts. The bottom of the entire device is arranged flush with the inner wall of the lining, and the gap between the device and the excavation surface is filled with an anti-filter material 6 to avoid clogging of the device.

[0027] As attached Figure 4 and 5 As shown, the outer tube 2 of the valve body includes an outer wall 2-1, an inner wall 2-2 and a connecting plate 2-3. The bottom of the outer wall 2-1 and the inner wall 2-2 are connected as a whole through the connecting plate 2-3. The height difference between the outer wall 2-1 and the inner wall 2-2 forms an annular gap-shaped water outlet. A water outlet hole 2-4 is processed on the connecting plate. After the upper end of the outer wall 2-1 shrinks inward, the inner diameter is consistent with the inner diameter of the inner wall 2-2. The end face forms a stop structure that cooperates with the piston to achieve sealing of the upper end of the valve body outer tube 2.

[0028] As attached Figure 6 As shown, the piston 3 is composed of a piston body 3-1 and a water stop strip 3-2. The water stop strip 3-2 is embedded in the top of the piston body 3-1 and at a position corresponding to the stop of the outer tube 2 of the valve body. The piston body 3-1 is composed of a sealing part and a supporting part. The middle section of the sealing part adopts an inner concave structure, and the disc structure at the upper and lower ends cooperates with the inner wall of the outer tube of the valve body to achieve sealing. The supporting part is located below the sealing part, and the supporting part is used to cover the spring 4.

[0029] The outer cylinder 2 of the valve body and the piston 3 are made of stainless steel or other materials with good durability and strength that meet the requirements. Before pouring the reinforced concrete lining 1, the outer cylinder 2 of the valve body needs to be embedded. To ensure that the outer cylinder 2 of the valve body is firmly embedded in the reinforced concrete lining 1, it can be fixed by embedding a steel pad or welding with the lining steel bars. After the outer cylinder 2 of the valve body is installed, the piston 3, the spring 4 and the bottom plate 5 can be installed in sequence. It should be noted that one end of the spring 4 is connected to the piston 3 and the other end is connected to the bottom plate 5. When installing the bottom plate 5, it needs to be connected and fixed with the outer cylinder connecting plate 2-3 by bolts.

[0030] The height of the water outlet between the outer wall 2-1 and the inner wall 2-2 of the valve body outer tube 2 can be determined according to the specific groundwater conditions, but the height of the gap must not exceed the thickness of the disc structure of the piston body 3-1 to prevent the piston 3 from tilting as a whole when it moves up and down under force.

[0031] As attached Figure 2 As shown, when the internal water pressure P1>external water pressure P2 and ΔP=P1-P2<set pressure difference P, the piston 3 moves upward, squeezing the stop at the top of the valve body outer tube 2, and the rubber water stop strip 3-2 seals and stops water to prevent internal water from seeping out.

[0032] As attached Figure 3 As shown, when ΔP=P1-P2≥the set pressure difference P, the piston 3 moves downward and the spring 4 is compressed. When the top plate of the piston 3 moves downward below the water outlet, external water enters the outer tube 2 of the valve body, and the water is discharged into the cavern through the water outlet and the water outlet holes 2-3 at the bottom of the outer tube. As the groundwater is discharged, the external water pressure P2 gradually decreases. When the conditions of the internal water pressure P1>external water pressure P2 and ΔP=P1-P2<the set pressure difference P are reached, the piston 3 moves upward and the spring 4 returns to its initial compression state.

[0033] Initial compression length of spring 4 Where P is the preset internal and external water pressure difference, which can be precisely controlled by adjusting the initial compression length of the spring 4 to meet the internal and external water pressure difference requirements of different projects.

[0034] After draining the water, the equipment can be inspected and replaced. The piston 3, spring 4 and bottom plate 5 are independent parts, which can be installed, repaired and replaced partially or as a whole. The replacement is convenient without damaging the original lining concrete structure, reducing the difficulty and economic cost of replacement.

[0035] 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 difference control device for a water-carrying underground cavern based on a double-layer outer cylinder, characterized in that: It includes a valve body outer cylinder, a piston, a spring and a bottom plate; The outer shape of the valve body outer cylinder is composed of two cylindrical sections. The large-diameter cylindrical section is a double-layer structure with both ends open. One end of the large-diameter cylindrical section forms an annular gap through the height difference between the inner and outer double-layer structures, and a water outlet hole is processed on the bottom surface of the other end; the front end of the small-diameter cylindrical section with a single-layer structure has a stop structure; The outer cylinder of the valve body is buried in the reinforced concrete lining, and the piston and spring are successively installed into the inner part of the outer cylinder of the valve body from the lower end of the outer cylinder of the valve body, and the two ends of the spring are respectively connected with the piston and the bottom plate, and the bottom plate is fixedly connected to the lower end of the outer cylinder of the valve body to close the open end and pre-tighten the spring at the same time. The pre-tightening force of the spring acts on the piston and makes the upper end of the piston cooperate with the stop structure to close the open end above the outer cylinder of the valve body; the piston is subjected to the action of the internal water pressure and the external water pressure at the same time. When the pressure difference between the internal and external water is greater than the starting pressure difference set by the piston, the device is started, the spring is compressed, and the external water enters from the upper end of the outer cylinder of the valve body and is discharged into the inner part of the reinforced concrete lining through the annular gap from the water outlet. As the external water is discharged, the pressure difference decreases, the spring stretches, the piston moves up and resets, and the device returns to the initial state. By adjusting the initial compression of the spring to set different starting pressure differences of the device, the pressure difference between the internal and external water is precisely controlled.

2. The pressure difference control device for a water-carrying underground cavern based on a double-layer outer cylinder according to claim 1, characterized in that: The outer cylinder of the valve body includes an outer wall, an inner wall and a connecting plate. The outer wall and the bottom of the inner wall are connected into one body through the connecting plate. The height difference between the outer wall and the inner wall forms an annular gap-shaped water outlet, and a water outlet hole is processed on the connecting plate.

3. The pressure difference control device for a water-carrying underground cavern based on a double-layer outer cylinder according to claim 2, characterized in that: The bottom of the pressure difference control device is arranged flush with the inner wall of the reinforced concrete lining, and the gap between the pressure difference control device and the excavation surface of the reinforced concrete lining is filled with filter material.

4. The pressure difference control device for a water-carrying underground cavern based on a double-layer outer cylinder according to claim 3 is characterized in that: The piston is composed of a piston body and a water stop strip, wherein the water stop strip is embedded in the top of the piston body and in a position corresponding to the stop of the outer cylinder of the valve body.

5. The pressure difference control device for a water-carrying underground cavern based on a double-layer outer cylinder according to claim 3 or 4, characterized in that: The piston body is composed of a sealing part and a supporting part. The middle section of the sealing part adopts a concave structure, and the disc structures at the upper and lower ends cooperate with the inner wall of the outer cylinder of the valve body to achieve sealing. The supporting part is located below the sealing part, and the supporting part is used to fit the spring.

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