Apparatus for maintaining water pressure in a blind tunnel and preventing air ingress and method of use

Abstract

The utility model relates to a device for keeping water pressure in a tunnel blind pipe and preventing air from entering and an application method, which comprises a connecting device and a pressure-keeping and air-preventing device. The connecting device comprises a pre-buried pipe, a fixing ring, a fixing steel bar and a flange. The pressure-keeping and air-preventing device comprises a water delivery pipe, an expansion tank, a water sealing plate and a spring. The front wall of the expansion tank is provided with three square openings from bottom to top, and each square opening is provided with a water sealing plate. The spring is hung on the lower part of the water sealing plate and the side wall of the expansion tank, and the opening and closing of the water sealing plate are controlled by the pushing force of the water pressure on the water sealing plate and the pulling force of the spring on the water sealing plate. The water sealing plates are opened in sequence from bottom to top according to the water pressure. The application method comprises the following steps: (1) reserving a space for installing the connecting device in the lining; (2) installing the connecting device, and filling the reserved space with concrete after the installation; (3) installing the pressure-keeping and air-preventing device, and opening the water sealing plates during the process; and (4) closing the water sealing plates, and starting the device.

Description

Technical Field

[0001] This invention relates to crystallization control technology within tunnel blind pipes. Background Technology

[0002] In tunnel structures, the primary function of blind drains is to collect and drain water accumulated in the surrounding rock after tunnel lining, ensuring the safe operation of the tunnel. However, in actual engineering, when water is about to be drained from the blind drain, air entering the drain causes certain ions in the water to react chemically with certain components in the air, forming crystals. Simultaneously, the reduced water pressure causes some crystals originally dissolved in the water to precipitate. These crystals accumulate in the blind drain, leading to poor drainage or even blockage, creating significant water pressure on the tunnel lining. In severe cases, this can even cause cracking or deformation of the tunnel lining, affecting its normal use.

[0003] To reduce drainage problems caused by water crystallization in blind pipes, the following measures are currently mainly adopted: (1) Injecting acidic solution into the blind pipe to clean the crystals. Although this method can remove some of the crystals, the acidic solution will corrode the concrete surface in the tunnel after being discharged from the blind pipe, making it unsuitable for on-site application. (2) Although methods to prevent air from entering the blind pipe are also used, the devices used in this method are large, inconvenient to use, and expensive, making it difficult to promote on-site. Therefore, a device that can effectively maintain water pressure in the blind pipe while preventing air from entering is urgently needed on-site. Summary of the Invention

[0004] The purpose of this invention is to provide a device and application method for maintaining water pressure inside a tunnel blind pipe and preventing air from entering.

[0005] This invention relates to a device and application method for maintaining water pressure inside a tunnel blind pipe and preventing air ingress. The device comprises a connecting device 1 and a pressure-maintaining and air-proofing device 2. The connecting device 1 includes four parts: a pre-embedded pipe 3, a fixing ring 4, a fixing steel bar 5, and a flange 6. The inner diameter of the pre-embedded pipe 3 is slightly larger than the outer diameter of the blind pipe 7, allowing it to fit over the blind pipe 7. The other end of the pre-embedded pipe is equipped with a flange 6, which has bolt holes 8. The pre-embedded pipe 3, the fixing ring 4, and the fixing steel bar 5 are fixed together. The pressure-holding and air-proof device 2 consists of four parts: a water supply pipe 10, an expansion box 11, a water sealing plate 12, and a spring 13. One end of the water supply pipe 10 is fixed to the expansion box 11, and the other end is connected to the pre-embedded pipe 3 through a flange 6. The expansion box 11 is a square box, and the rear wall 14 of the expansion box is fixed to the water supply pipe 10. The front wall 15 of the expansion box has three square openings 16 from bottom to top. Each square opening 16 is equipped with a water sealing plate 12. The three square openings 16 have the same structure and size, and the three water sealing plates 12 have the same structure and size.

[0006] The application method of the device for maintaining water pressure and preventing air ingress in a tunnel blind pipe according to the present invention comprises the following steps:

[0007] Step (1) During the construction of lining 9, a reserved space 23 is installed at the end of blind pipe 7 for the installation of connecting device 1;

[0008] Step (2) Install the connecting device 1 at the reserved space 23 at the end of the blind pipe 7, and put the pre-embedded pipe 3 over the blind pipe 7;

[0009] Step (3) Overlap the fixed steel bar 5 of the connecting device 1 with the pre-embedded steel bar 24 in the tunnel lining, and connect the fixed steel bar 5 and the pre-embedded steel bar 24 in the lining by welding, and fill the reserved space 23 with concrete.

[0010] Step (4) During the above process, pay attention to clearing and protecting the water flowing out of the blind pipe 7 to avoid affecting the construction; Step (5) After the concrete strength reaches the design requirements, install the pressure holding and air prevention device 2;

[0011] During installation, the water sealing plate 12 should be kept open to ensure that the water in the blind pipe 7 is drained.

[0012] After the pressure holding and anti-air device 2 is installed in step (6), close the water sealing plate 12 and the whole equipment will start working.

[0013] The beneficial effects of this invention are: the device can control the opening and closing of the sealing plate according to the water pressure, thus ensuring water pressure. Simultaneously, when the water pressure is high enough to open the sealing plate, the device is always full of water, preventing air from entering during water discharge, thus preventing air ingress. These two functions effectively prevent water crystallization within the blind pipe and prevent blockage. The device has a simple structure and strong applicability. It ensures both project quality and drainage efficiency without polluting the environment, resulting in significant economic benefits and good application value. Attached Figure Description

[0014] Figure 1 This is an overall diagram of the equipment used to maintain water pressure inside the blind tunnel and prevent air from entering. Figure 2 This is an overall diagram of the connecting device. Figure 3 This is a 3D diagram showing how to maintain water pressure inside the tunnel blind pipe and prevent air from entering the equipment. Figure 4 This is section view I-I. Figure 5 This is section view II-II. Figure 6 This is a diagram of the front wall of the expansion tank (with a water sealing plate). Figure 7 This is a diagram of the front wall of the expansion tank (without a water seal plate). Figure 8 This is a 3D diagram of the water sealing plate (without connecting shafts). Figure 9 This is a 3D diagram of the water sealing plate (with connecting shafts). Figure 10 This is section III-III. Figure 11 This is section IV-IV. Figure 12 This is a structural dimension drawing based on section III-III. Figure 13 It is a structural dimension drawing based on section V-V. Figure 14 This is a schematic diagram of the longitudinal section of the connecting device installation. Detailed Implementation

[0015] This invention relates to a device and application method for maintaining water pressure and preventing air ingress within a tunnel blind pipe. The device comprises a connecting device 1 and a pressure-maintaining and air-preventing device 2. The connecting device 1 includes four parts: a pre-embedded pipe 3, a fixing ring 4, a fixing steel bar 5, and a flange 6. The inner diameter of the pre-embedded pipe 3 is slightly larger than the outer diameter of the blind pipe 7, allowing it to fit over the blind pipe 7. The other end of the pre-embedded pipe is equipped with a flange 6, which has bolt holes 8. The pre-embedded pipe 3, the fixing ring 4, and the fixing steel bar 5 are fixed together. Together; the pressure holding and air-proof device 2 includes four parts: water supply pipe 10, expansion box 11, sealing plate 12, and spring 13; one end of the water supply pipe 10 is fixed together with the expansion box 11, and the other end is connected to the pre-embedded pipe 3 through flange 6; the expansion box 11 is a square box, the rear wall 14 of the expansion box is fixed together with the water supply pipe 10, and the front wall 15 of the expansion box has three square openings 16 from bottom to top; each square opening 16 is equipped with a sealing plate 12; the three square openings 16 have the same structure and size, and the three sealing plates 12 have the same structure and size.

[0016] The device described above has a rotating hole 17 on the upper part of the water sealing plate 12, and a connecting shaft 18 connects the rotating hole 17 of the water sealing plate 12 to the reserved hole 19 on the side of the square opening 16; the water sealing plate 12 can rotate around the connecting shaft 18; there are baffles 20 on the top, bottom and sides of the square opening 16.

[0017] The device described above has a ring 21 at each end of the lower part of the water sealing plate 12 to hold the spring 13. The other end of the spring 13 is hung on the ring 21 on the side wall 22 of the expansion tank. When the water sealing plate 12 is opened to release water, the lower water sealing plate A12-1 is opened first to release water. If the water pressure continues to rise, the middle water sealing plate B12-2 is opened to release water. If the water pressure still continues to rise, the upper water sealing plate C12-3 is opened to release water. The control force for opening the water sealing plate 12 is provided by the tension of the spring 13. The tension of the three sets of springs 13 from bottom to top is also different, with two springs in each set. The three sets of springs 13 are of the same length. From bottom to top, the three sets of springs 13 are spring A13-1, spring B13-2, and spring C13-3, with elastic coefficients k1, k2, and k3, respectively. <k2<k3。

[0018] The opening and closing of the lower sealing plate A12-1, which is used to maintain water pressure and prevent air from entering the tunnel blind pipe, as described above, is calculated using the following formula (the calculation formula is the same for other sealing plates, only the spring constant is taken as a different value):

[0019] Water pressure-bearing area of ​​sealing plate A12-1: s=b1×h2

[0020] The pressure on the sealing plate A12-1 is: f1 = p1 × s = p1 × b1 × h2

[0021] The torque exerted by the water pressure on the sealing plate A12-1 on its connecting shaft 18 is: f1×(h2 / 2+h3)=p1×b1×h2×(h2 / 2+h3)

[0022] The tension in a spring A13-1 is: f2 = k1 × Δl1

[0023] The torque exerted by the tension of spring group A13-1 on the connecting shaft 18 of water sealing plate A12-1 is (one set of springs A13-1 consists of two springs):

[0024] 2×f2×h1=2×k1×Δl1×h1

[0025] When the torque generated by the tension of spring A13-1 on the sealing plate A12-1 is not less than the torque generated by the water pressure on the sealing plate A12-1, the formula is satisfied:

[0026] p1×b1×h2×(h2 / 2+h3)≤2×k1×Δl1×h1 (1)

[0027] When the water seal plate A12-1 is in a certain condition, it will not open; otherwise, it will open to release water.

[0028] Where: b1 - width of the sealing plate A12-1 under water pressure; h1 - distance from the center of spring A13-1 to the center of the connecting shaft 18 of the sealing plate A12-1; h2 - height of the sealing plate A12-1 under water pressure; h3 - distance from the edge of the baffle 20 to the center of the connecting shaft 18; p1 - minimum pressure to prevent water from crystallizing, determined by experimental measurements and engineering experience; Δl1 - elongation of spring A13-1, calculated by Δl1 = l1 - l0, where: l1 - actual length of spring A13-1, l0 - initial length of spring A13-1; k1 - elastic coefficient of spring A13-1;

[0029] When the lower water sealing plate A12-1 is fully opened, the water pressure continues to increase. When it increases to p2 (50% of the maximum water pressure that the tunnel lining can withstand), the middle water sealing plate B12-2 is opened to release water. At this time, the elastic coefficient k2 of the spring B13-2 can be calculated and determined by formula (1), and the pressure is taken as p2.

[0030] When the pressure increases to p3, which is 80% of the maximum water pressure that the tunnel lining can withstand, the upper water sealing plate C12-3 opens to release water. At this time, the elastic coefficient k3 of the spring C13-3 can be calculated and determined by formula (1), and the pressure is taken as p3.

[0031] The application method of the device for maintaining water pressure and preventing air ingress in a tunnel blind pipe according to the present invention comprises the following steps:

[0032] Step (1) During the construction of lining 9, a reserved space 23 is installed at the end of blind pipe 7 for the installation of connecting device 1;

[0033] Step (2) Install the connecting device 1 at the reserved space 23 at the end of the blind pipe 7, and put the pre-embedded pipe 3 over the blind pipe 7;

[0034] Step (3) Overlap the fixed steel bar 5 of the connecting device 1 with the pre-embedded steel bar 24 in the tunnel lining, and connect the fixed steel bar 5 and the pre-embedded steel bar 24 in the lining by welding, and fill the reserved space 23 with concrete.

[0035] Step (4) During the above process, pay attention to clearing and protecting the water flowing out of the blind pipe 7 to avoid affecting the construction; Step (5) After the concrete strength reaches the design requirements, install the pressure holding and air prevention device 2;

[0036] During installation, the water sealing plate 12 should be kept open to ensure that the water in the blind pipe 7 is drained.

[0037] After the pressure holding and anti-air device 2 is installed in step (6), close the water sealing plate 12 and the whole equipment will start working.

[0038] The invention will be further elaborated below with reference to the accompanying drawings:

[0039] like Figure 1 As shown, this invention is a device for maintaining water pressure inside a tunnel blind pipe and preventing air from entering, comprising two parts: a connecting device 1 and a pressure-maintaining and air-preventing device 2. Figure 2 , Figure 3 As shown, the connecting device 1 comprises four parts: a pre-embedded pipe 3, a fixing ring 4, a fixing reinforcing bar 5, and a flange 6. The inner diameter of the pre-embedded pipe 3 is slightly larger than the outer diameter of the blind pipe 7, allowing it to be fitted over the blind pipe 7. The other end of the pre-embedded pipe is equipped with a flange 6, which has bolt holes 8. The pre-embedded pipe 3, the fixing ring 4, and the fixing reinforcing bar 5 are fixed together to secure the pre-embedded pipe 3 within the tunnel lining 9, thereby enhancing the connection performance between the entire device and the tunnel lining 9.

[0040] like Figures 3-7 As shown, the pressure-maintaining and air-prevention device 2 comprises four parts: a water supply pipe 10, an expansion tank 11, a water-sealing plate 12, and a spring 13. One end of the water supply pipe 10 is fixed to the expansion tank 11, and the other end is connected to the pre-embedded pipe 3 via a flange 6. The expansion tank 11 is a square box, with its rear wall 14 fixed to the water supply pipe 10. The front wall 15 of the expansion tank has three square openings 16 from bottom to top. Each square opening 16 is equipped with a water-sealing plate 12 to maintain water pressure and prevent air from entering. The three square openings 16 have the same structure and dimensions, as do the three water-sealing plates 12.

[0041] like Figures 8-11 As shown, the water-sealing plate 12 has a rotating hole 17 on its upper part. A connecting shaft 18 connects the rotating hole 17 of the water-sealing plate 12 to the reserved hole 19 on the side of the square opening 16. The water-sealing plate 12 can rotate around the connecting shaft 18 to achieve the purpose of opening and closing. There are baffles 20 on the top, bottom and sides of the square opening 16, which can fix the position of the water-sealing plate 12, balance the tension of the spring 13, and also play a sealing role to prevent water leakage when the water-sealing plate 12 is not opened.

[0042] like Figure 4 , Figure 5As shown, a ring 21 is provided at each of the lower ends of the water sealing plate 12 to hold the spring 13. The other end of the spring 13 is hung on the ring 21 on the side wall 22 of the expansion tank. The opening and closing of the water sealing plate 12 is controlled by the magnitude of the pushing force of the water pressure on the water sealing plate 12 and the pulling force of the spring 13 on the water sealing plate 12. When the water sealing plate 12 is opened to release water, the lower water sealing plate A12-1 is opened first to release water; if the water pressure continues to rise, the middle water sealing plate B12-2 is opened to release water; if the water pressure still continues to rise, the upper water sealing plate C12-3 is opened to release water. The control force when the water sealing plate 12 is opened is mainly provided by the pulling force of the spring 13, and the pulling force of the three sets of springs 13 from bottom to top is also different (two springs in each set). The three sets of springs 13 are of the same length. From bottom to top, the three sets of springs 13 are spring A13-1, spring B13-2, and spring C13-3, with spring constants k1, k2, and k3, respectively. <k2<k3。

[0043] like Figure 12 , Figure 13 As shown, the opening and closing of the water seal plate 12 is calculated using the following formula: Taking the lower layer water seal plate A12-1 as an example:

[0044] Water pressure-bearing area of ​​sealing plate A12-1: s=b1×h2

[0045] The pressure on the sealing plate A12-1 is: f1 = p1 × s = p1 × b1 × h2

[0046] The torque exerted by the water pressure on the sealing plate A12-1 on its connecting shaft 18 is:

[0047] f1×(h2 / 2+h3)=p1×b1×h2×(h2 / 2+h3)

[0048] The tension in a spring A13-1 is: f2 = k1 × Δl1

[0049] The torque exerted by the tension of spring group A13-1 on the connecting shaft 18 of water sealing plate A12-1 is (one set of springs A13-1 consists of two springs):

[0050] 2×f2×h1=2×k1×Δl1×h1

[0051] When the torque generated by the tension of spring A13-1 on the sealing plate A12-1 is not less than the torque generated by the water pressure on the sealing plate A12-1, the formula is satisfied:

[0052] p1×b1×h2×(h2 / 2+h3)≤2×k1×Δl1×h1 (1)

[0053] When the water seal plate A12-1 is open, it will not open; otherwise, it will open to release water.

[0054] Wherein: b1 - the width of the water-sealing plate A12-1 under water pressure; h1 - the distance from the center of the spring A13-1 to the center of the connecting shaft 18 of the water-sealing plate A12-1; h2 - the height of the water-sealing plate A12-1 under water pressure; h3 - the distance from the edge of the baffle 20 to the center of the connecting shaft; p1 - the minimum pressure to prevent water from crystallizing, which is determined by experimental measurements and engineering experience.

[0055] Δl1 - the elongation of spring A13-1, calculated by Δl1 = l1 - l0, where: l1 - the actual length of spring A13-1, l0 - the initial length of spring A13-1; k1 - the elastic coefficient of spring A13-1.

[0056] After the lower water sealing plate A12-1 is fully opened, the water pressure continues to increase. When it increases to p2 (50% of the maximum water pressure that the tunnel lining can withstand), the middle water sealing plate B12-2 opens to release water. At this time, the elastic coefficient k2 of the spring B13-2 can be calculated and determined by formula (1) (the pressure is taken as p2). When it increases to p3 (80% of the maximum water pressure that the tunnel lining can withstand), the upper water sealing plate C12-3 opens to release water. At this time, the elastic coefficient k3 of the spring C13-3 can be calculated and determined by formula (1) (the pressure is taken as p3).

Claims

1. Equipment for maintaining water pressure in a blind tunnel and preventing air from entering, comprising two parts, a connecting device (1) and a pressure-maintaining and air-preventing device (2), characterised in that The connecting device (1) comprises a pre-buried pipe (3), a fixing ring (4), a fixing steel bar (5) and a flange plate (6). The inner diameter of the pre-buried pipe (3) is slightly larger than the outer diameter of the blind pipe (7) so that the pre-buried pipe (3) can be sleeved on the blind pipe (7). The other end of the pre-buried pipe (3) is provided with the flange plate (6) which is provided with bolt holes (8). The pre-buried pipe (3), the fixing ring (4) and the fixing steel bar (5) are fixed together. The pressure maintaining and air preventing device (2) comprises a water delivery pipe (10), an expansion tank (11), a water sealing plate (12) and a spring (13). One end of the water delivery pipe (10) is fixed with the expansion tank (11), and the other end is connected with the pre-buried pipe (3) through the flange plate (6). The expansion tank (11) is a square tank. The rear wall (14) of the expansion tank is fixed with the water delivery pipe (10), and the front wall (15) of the expansion tank is provided with three square openings (16) which are opened from bottom to top. Each square opening (16) is provided with a water sealing plate (12). The three square openings (16) have the same structure and size, and the three water sealing plates (12) have the same structure and size. The upper part of the water sealing plate (12) is provided with a rotating hole (17). A connecting shaft (18) is used to connect the rotating hole (17) of the water sealing plate (12) and the reserved hole (19) on the side of the square opening (16). The water sealing plate (12) can rotate around the connecting shaft (18). The square opening (16) is provided with a blocking strip (20) on the top, the bottom and the two sides. The lower part of the water sealing plate (12) is provided with a circular ring (21) at each end for hanging the spring (13). The other end of the spring (13) is hung on the circular ring (21) on the side wall (22) of the expansion tank. When the water sealing plate (12) is opened to release water, the lower water sealing plate A (12-1) is opened first to release water. If the water pressure continues to rise, the middle water sealing plate B (12-2) is opened to release water. If the water pressure continues to rise, the upper water sealing plate C (12-3) is opened to release water. The control force when the water sealing plate (12) is opened is provided by the tension of the spring (13). The tension of the three groups of springs (13) from bottom to top is different, and each group has two springs. The lengths of the three groups of springs (13) are the same. The three groups of springs (13) are spring A (13-1), spring B (13-2) and spring C (13-3) from bottom to top. The elastic coefficients of the three groups of springs (13) are k1, k2 and k3, and k1 < k2 < k3. The opening and closing of the water sealing plate (12) is calculated by the following formula. The following formula is used to calculate the lower water sealing plate A (12-1). The calculation formula of other water sealing plates is the same, except that the elastic coefficient of the spring is different. The water pressure area of the water sealing plate A (12-1) is s = b1 × h2. The pressure of the water sealing plate A (12-1) is f1 = p1 × s = p1 × b1 × h2. The moment of the water pressure of the water sealing plate A (12-1) on the connecting shaft (18) is f1 × (h2 / 2 + h3) = p1 × b1 × h2 × (h2 / 2 + h3). The tension of a spring A (13-1) is f2 = k1 × Δl1. The moment of the tension of a group of spring A (13-1) on the connecting shaft (18) is ​ 2 x f2 x h1 = 2 x k1 x Δl1 x h1 When the moment of the pulling force of spring A (13-1) on the water sealing plate A (12-1) is not less than the moment of the water pressure on the water sealing plate A (12-1), i.e. when the formula (1) is satisfied, the water sealing plate A (12-1) will not open; otherwise, the water sealing plate will open to release water; Wherein: b1 - the width of the water sealing plate A (12-1) under the water pressure; h1 - the distance from the center of the spring A (13-1) to the center of the connecting shaft (18) of the water sealing plate A (12-1); h2 - the height of the water sealing plate A (12-1) under the water pressure; h3 - the distance from the edge of the blocking strip (20) to the center of the connecting shaft (18); p1 - the minimum pressure to prevent the water from crystallizing, which is determined by test and engineering experience; Δl1 - the elongation of the spring A (13-1), which is calculated by Δl1 = l1 - l0, wherein: l1 - the actual length of the spring A (13-1), l0 - the initial length of the spring A (13-1); k1 - the elastic coefficient of the spring A (13-1); When the lower water sealing plate A (12-1) is completely opened, the water pressure continues to increase to 50% of the maximum water pressure that the tunnel lining can bear, the middle water sealing plate B (12-2) opens to release water, at this time the elastic coefficient k2 of the spring B (13-2) can be determined by the formula (1), and the pressure is taken as p2. When it increases to p3, i.e. 80% of the maximum water pressure that the tunnel lining can bear, the upper water sealing plate C (12-3) opens to release water, at this time the elastic coefficient k3 of the spring C (13-3) can be determined by the formula (1), and the pressure is taken as p3. The steps are as follows:

2. The method of using the apparatus for maintaining water pressure in a blind tunnel and preventing air from entering according to claim 1, wherein, Step (1) when the lining (9) is constructed, a reserved space (23) is provided at the end of the blind pipe (7) for installing the connecting device (1); Step (2) the connecting device (1) is installed at the reserved space (23) at the end of the blind pipe (7), and the embedded pipe (3) is sleeved outside the blind pipe (7); Step (3) the fixing steel bars (5) of the connecting device (1) are overlapped with the embedded steel bars (24) in the tunnel lining, and the fixing steel bars (5) and the embedded steel bars (24) in the lining are connected by welding, and the reserved space (23) is filled with concrete; Step (4) during the above process, the water flowing out of the blind pipe (7) is dredged and protected to avoid affecting the construction; Step (5) after the concrete strength reaches the design requirement, the pressure maintaining and airproof device (2) is installed; During the installation process, the water sealing plate (12) is in the open state to ensure that the water in the blind pipe (7) is discharged; Step (6) after the pressure maintaining and airproof device (2) is installed, the water sealing plate (12) is closed, and the whole device starts to work. ​

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