Deeply-buried hydraulic tunnel external water pressure reduction control device easy to disassemble and replace

Abstract

The invention discloses a deep-buried hydraulic tunnel external water pressure reduction control device easy to disassemble and replace. The deep-buried hydraulic tunnel external water pressure reduction control device comprises an outer cylinder, a piston, a spring and a bottom plate. The outer cylinder is embedded in a reinforced concrete lining, the piston and the spring are sequentially installed in the outer cylinder from the tail end of the outer cylinder, the two ends of the spring are connected with the piston and the bottom plate respectively, the bottom plate is fixedly connected to the end face of the tail end of the outer cylinder and pre-tightens the spring, and the pre-tightening force of the spring acts on the piston and enables the upper end of the piston to seal the open end of the head end of the outer cylinder. The piston bears the effects of internal water pressure and external water pressure at the same time, when the internal and external water pressure difference is larger than the starting pressure difference set by the piston, the device is started, the spring is compressed, external water is discharged, along with external water discharging, the pressure difference is reduced, 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, and accurate control is carried out. During replacement and maintenance, only the bottom plate needs to be detached, replacement is convenient, and the lining structure is not damaged.

Description

Technical Field

[0001] The invention relates to the field of engineering technology, and in particular to an easily disassembled and replaced external water pressure reduction control device for a deep-buried hydraulic tunnel. Background Art

[0002] Deep buried hydraulic tunnels often bring about the problem of high external water pressure, which brings great challenges to the design of concrete lining structures of pressurized hydraulic tunnels. When the external water pressure is too high, the force of the tunnel lining structure is mainly determined by the external water pressure it bears. High external water pressure leads to a significant increase in the thickness and reinforcement of the tunnel lining, which not only increases the project investment, but also fails to ensure the safety and stability of the lining structure. For deep buried tunnel structures, the current common design method is to use a composite load-bearing and anti-seepage structure formed by a consolidation grouting ring and a concrete lining. The consolidation grouting ring bears the huge external water pressure, while the concrete lining is generally limited by the size of the structure and has limited ability to resist external water pressure. Pressure relief holes are often arranged on the concrete lining according to the size of the external water pressure to ensure the safety of the lining structure against external pressure. The method of arranging pressure relief holes on the tunnel lining concrete structure to form a permeable lining is feasible in tunnel sections with high external water pressure. However, considering that the external water pressure may change due to the recharge situation after the tunnel is put into operation, when the internal water pressure is greater than the external water pressure, it will cause water in the pressurized water tunnel to seep out, causing 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 the groundwater level, bringing a series of ecological and environmental problems.

[0003] Based on the above analysis, the current underground water tunnel seepage and drainage systems have the following main problems: First, it is impossible to prevent internal water from seeping out and is difficult to repair and replace; second, it is impossible to accurately control the internal and external water pressure difference, which either leads to excessive discharge of external water, causing ecological and environmental problems, or causes structural safety problems due to the inability to discharge external water; third, the drainage system has a complex structure and high construction and maintenance costs. Summary of the invention

[0004] In view of this, the present invention provides an external water pressure reduction control device for a deep-buried hydraulic tunnel that is easily disassembled and replaced. When the external water pressure exceeds a set value, the external water pressure reduction device can discharge the external water into the tunnel, thereby achieving the purpose of reducing the external water pressure and controlling the external water discharge volume at the same time.

[0005] An easily disassembled and replaced external water pressure reduction control device for a deep-buried hydraulic tunnel comprises an outer cylinder, a piston, a spring and a bottom plate;

[0006] The outer cylinder is buried in the reinforced concrete lining, and the head and tail ends of the outer cylinder are in an open state; the piston and the spring are sequentially installed into the outer cylinder from the tail end of the 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 end surface of the tail end of the outer cylinder and pre-tightens the spring, and the pre-tightening force of the spring acts on the piston and causes the upper end of the piston to close the open end of the head end of the outer cylinder; the piston is subjected to the action of the internal water pressure and the external water pressure at the same time, and 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 the external water is discharged, and 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, and different device starting pressure differences are set by adjusting the initial compression amount of the spring for precise control.

[0007] Furthermore, the bottom plate is connected to a steel plate embedded in the reinforced concrete lining by self-tightening bolts, and the steel plate is connected to the lining stress-bearing steel bars by welding.

[0008] Furthermore, the bottom of the pressure reduction control device is arranged flush with the inner wall of the reinforced concrete lining, and the gap between the pressure reduction control device and the excavation surface is filled with filter material.

[0009] Furthermore, a gap is provided between the piston and the outer cylinder, a circle of small drainage holes is provided on the outer edge of the piston bottom plate, and a large drainage hole is provided on the bottom plate; when the piston moves downward, groundwater flows into the tunnel through the gap between the piston and the outer cylinder, the small drainage holes on the outer edge of the piston bottom plate, and the large drainage hole on the bottom plate.

[0010] Furthermore, the sum of the areas of the small drainage holes on the piston bottom plate and the bottom plate is equal to the area of ​​the large drainage holes.

[0011] Furthermore, a rubber water stop strip is provided on the side of the piston top plate.

[0012] Beneficial effects:

[0013] 1. The present invention sets an external water pressure reduction control device in the reinforced concrete lining. When the external water of the lining exceeds a preset pressure difference, the device is started, 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 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 compression 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 main structure of the external water pressure reduction control device of the present invention is composed of an independent outer cylinder and an internal piston and spring. The internal piston and spring can be installed, repaired and replaced separately, reducing the difficulty and economic cost of replacement.

[0015] 3. The present invention has a simple structure and reasonable design, and can be partially or completely installed, repaired and replaced. Replacement and repair only require disassembly of the bottom plate, which is convenient and does not damage the lining concrete structure.

[0016] 4. The gap between the pressure reduction control device of the present invention and the excavation surface is filled with filter material, which can effectively avoid clogging of the device. The bottom plate is connected to the steel pad embedded in the reinforced concrete lining by self-tightening bolts to avoid loosening of the bolts due to water flow agitation, device vibration, etc. during the operation of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the installation position 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 This is a cross-sectional view (AA) of the top plate of the outer cylinder of the device of the present invention in the initial state;

[0021] Figure 5 This is a cross-sectional view (BB) of the piston bottom plate of the device of the present invention in the initial state;

[0022] Figure 6 This is a cross-sectional view (CC) of the outer cylinder bottom plate of the device of the present invention in the initial state;

[0023] Figure 7 It is a top view of the steel pad of the device of the present invention;

[0024] Figure 8 This is a large-scale drawing of the connection between the outer cylinder bottom plate and the steel backing plate of the device of the present invention;

[0025] Fig. 9 It is a cross-sectional view of the outer cylinder in the present invention;

[0026] Fig.10 It is a cross-sectional view of the piston and the spring in the present invention;

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

[0028] Among them, 1-surrounding rock mass, 2-tunnel, 3-reinforced concrete lining, 4-outer cylinder, 5-piston, 6-water stop strip, 7-spring, 8-bottom plate, 9-filter material, 10-steel pad, 11-self-tightening bolt, 12-lining stress reinforcement, 13-small drainage hole, 14-large drainage hole. DETAILED DESCRIPTION

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

[0030] The present invention provides an easily disassembled and replaced external water pressure reduction control device for a deep-buried hydraulic tunnel, as shown in the attached Figure 1 As shown, the reinforced concrete lining 3 is buried inside the surrounding rock mass 1 , the space inside the reinforced concrete lining 3 is the tunnel 2 , and the pressure reduction control device of the present invention is arranged on the reinforced concrete lining 3 .

[0031] The pressure reduction control device comprises an outer cylinder 4, a piston 5, a water stop strip 6, a spring 7, a bottom plate 8, a filter material 9, a steel backing plate 10 and a self-tightening bolt 11; wherein, as shown in the attached Fig. 9 As shown, the outer tube 4 is composed of a conical section and a cylindrical section. The outer tube 4 is open at both ends. A conical hole is opened on the top plate of the conical section. The conical hole cooperates with the top plate of the piston 5 to achieve sealing of the head end.

[0032] As attached Figure 2 As shown, the outer tube 4 is buried in the reinforced concrete lining 3, the bottom plate 8 is installed close to the bottom of the outer tube 4, the bottom plate 8 is connected to the steel plate 10 embedded in the reinforced concrete lining by self-tightening bolts 11, and the steel plate 10 is welded to the lining stress steel bar 12, as shown in the attached Figure 8 The piston 5 is installed inside the valve body outer cylinder 4, and a gap is provided between the piston 5 and the outer cylinder 4. Figure 4 As shown, a rubber water stop strip 6 is provided on the side of the top plate of the piston 5, and the piston 5 can move up and down after being stressed. One end of the spring 7 is connected to the piston 5, and the other end is connected to the bottom plate of the outer cylinder 4. The bottom of the entire device is arranged flush with the inner wall of the reinforced concrete lining 3. The gap between the device and the excavation surface is filled with filter material 9 to avoid clogging of the device. Figure 5 As shown, a plurality of small drainage holes 13 are provided on the bottom plate of the piston 5. Figure 6 As shown, a large drainage hole 14 is set on the bottom plate 8, and the sum of the areas of all the small drainage holes 13 is equal to the area of ​​the large drainage hole 14. When the piston 5 moves downward, groundwater can flow into the tunnel through the gap between the piston 5 and the outer cylinder 4, the small drainage holes 13 on the outer edge of the bottom plate of the piston 5, and the large drainage hole 14 on the bottom plate 8.

[0033] The outer cylinder 4, piston 5, bottom plate 7, and steel pad 9 can be made of stainless steel or other materials with good durability and strength that meet the requirements. Before pouring the reinforced concrete lining 3, the outer cylinder 4 and steel pad 10 need to be pre-buried, and the steel pad 10 is welded to the lining force-bearing steel bar 12 to ensure the stability of the steel pad 10. After the outer cylinder 4 and the steel pad 10 are installed, the piston 5, the spring 7, and the bottom plate 8 can be installed in sequence. It should be noted that one end of the spring 7 is connected to the piston 5, and the other end is connected to the bottom plate 8. The bottom plate 8 is installed close to the bottom of the outer cylinder 4, and the bottom plate 8 is connected to the steel pad 10 by self-tightening bolts 11, which ensures that the outer cylinder 4 and the bottom plate 8 are fixed in the concrete lining 3. By using self-tightening bolts 11, the bolts are prevented from loosening due to water flow agitation, device vibration, etc. during the operation of the device.

[0034] As attached Figure 1 and 2 As shown, the piston 5 is subjected to the internal water pressure P1 and the external water pressure P2 at the same time, and the internal and external water pressure difference ΔP = P2-P1. Fig.11 As shown, assuming that the original height of the spring is h0, the height after installation is h1, and the initial compression is P is the set starting pressure difference, and k is the spring coefficient.

[0035] ① When the internal water pressure P1>external water pressure P2 and ΔP=P1-P2<the set device startup pressure difference P, the piston moves up, squeezes the top of the valve body outer cylinder 4, and the rubber water stop strip 6 seals and stops water to prevent the internal water from leaking out. Figure 2 ② When ΔP=P1-P2≥the set device starting pressure difference P, the piston 5 moves down, the spring 7 is compressed, and the external water is discharged. The state is as shown in the attached figure. Figure 3 As shown, water is discharged into the tunnel through the gap between the outer tube 4 and the piston 5, the small drainage holes on the outer edge of the bottom plate of the piston 5 and the large drainage holes on the bottom plate 8. As the groundwater is discharged, the external water pressure P2 gradually decreases. When the condition ① is met, the piston 6 moves up and the spring 7 returns to its initial compressed state.

[0036] The initial compression length of spring 6 is The initial compression of the spring can be adjusted to set different device starting pressure differences P for precise control.

[0037] Assuming that the tunnel diameter is D, the drainage hole area (the sum of the small drainage hole area and the large drainage hole area) is A, the average flow rate of external water in the drainage hole is v, and the number of devices arranged per linear meter of tunnel is b, then the groundwater flow rate per linear meter of tunnel is Q = b × v × A (m 3 / s). Through this device, the maximum external water head at the top of the tunnel can be effectively reduced by

[0038] After draining the water, you can repair and replace the equipment. Fig.10As shown, the piston 5, spring 7 and base plate 8 are independent parts, which can be partially or completely installed, repaired and replaced. The replacement is convenient without damaging the original lining concrete structure, thus reducing 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. An easily disassembled and replaced deep-buried hydraulic tunnel external water pressure reduction control device, characterized in that: It includes an outer cylinder, a piston, a spring and a base plate; The outer cylinder is buried in the reinforced concrete lining, and the head and tail ends of the outer cylinder are in an open state; the piston and the spring are sequentially installed into the outer cylinder from the tail end of the 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 end surface of the tail end of the outer cylinder and pre-tightens the spring, and the pre-tightening force of the spring acts on the piston and causes the upper end of the piston to close the open end of the head end of the outer cylinder; the piston is subjected to the action of the internal water pressure and the external water pressure at the same time, and 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 the external water is discharged, and 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, and different device starting pressure differences are set by adjusting the initial compression amount of the spring for precise control.

2. The easily disassembled and replaceable deep-buried hydraulic tunnel external water pressure reduction control device according to claim 1, characterized in that: The bottom plate is connected to a steel backing plate embedded in the reinforced concrete lining through self-tightening bolts, and the steel backing plate is connected to the lining stress-bearing steel bars by welding.

3. The easily disassembled and replaceable deep-buried hydraulic tunnel external water pressure reduction control device as claimed in claim 2, characterized in that: The bottom of the pressure reduction control device is arranged flush with the inner wall of the reinforced concrete lining, and the gap between the pressure reduction control device and the excavation surface is filled with filter material.

4. The easily disassembled and replaceable deep-buried hydraulic tunnel external water pressure reduction control device as claimed in claim 3, characterized in that: A gap is provided between the piston and the outer cylinder, a circle of small drainage holes is provided on the outer edge of the piston bottom plate, and a large drainage hole is provided on the bottom plate; when the piston moves downward, groundwater flows into the tunnel through the gap between the piston and the outer cylinder, the small drainage holes on the outer edge of the piston bottom plate, and the large drainage hole on the bottom plate.

5. The easily disassembled and replaceable deep-buried hydraulic tunnel external water pressure reduction control device as claimed in claim 4, characterized in that: The sum of the areas of the small drainage holes on the piston bottom plate and the bottom plate is equal to the area of ​​the large drainage holes.

6. An easily disassembled and replaceable deep-buried hydraulic tunnel external water pressure reduction control device as claimed in claim 4 or 5, characterized in that: A rubber water stop strip is arranged on the side of the piston top plate.

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