Drilling and blasting method subsea tunnel waterproof and drainage system and implementation method thereof

Abstract

The invention provides a drilling and blasting method subsea tunnel waterproof and drainage system and an implementation method thereof.The waterproof and drainage system comprises an annular drainage mechanism, a water drainage mechanism and a water drainage mechanism, the longitudinal drainage mechanism comprises longitudinal drainage pipes and tunnel drainage ditches, and the longitudinal drainage pipes are arranged at the wall feet of the two side edges of the tunnel lining; the tunnel drainage ditch is arranged at a tunnel inverted arch; the transverse drainage mechanism comprises two transverse water guide pipes arranged on the section and on the left side and the right side of the tunnel, one ends of the two transverse water guide pipes are connected with the annular drainage pipe and the longitudinal drainage pipe respectively, and the other ends of the two transverse water guide pipes are connected with a tunnel drainage ditch; the water pressure sensing and overpressure drainage mechanism comprises a water pressure gauge and an overpressure drainage device, and the water pressure gauge is used for measuring the water pressure at the bottom of the tunnel; and the overpressure drainage device is connected with the end part of the transverse water conduit and is used for timely draining underground water when a preset water pressure value is exceeded. According to the method, accurate control over drainage in the operation period of the subsea tunnel through the drilling and blasting method can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of submarine tunnel engineering, and in particular to a drill-and-blast submarine tunnel drainage system and an implementation method thereof. Background Art

[0002] At present, there are more and more submarine tunnels under construction and planning in my country, and there is a trend towards high water pressure and long distance. For example, the second submarine tunnel in Jiaozhou Bay under construction has a maximum water head of 114m and is 13.5km long. The planned major projects such as the Qiongzhou Strait Cross-sea Channel and the Bohai Strait Cross-sea Channel will have higher water pressure and longer distance. For long-distance, high-water-pressure submarine tunnels, the key to ensuring the safety, economy and rationality of tunnel construction and operation is to reasonably control the water pressure behind the lining and the amount of water inflow in the tunnel. At present, the drainage system of the submarine tunnel using the drilling and blasting method is divided into "fully enclosed mode", "fully drained mode" and "limited drained mode". The second lining of the tunnel in the "fully enclosed mode" needs to withstand all water pressure, which is generally suitable for tunnels with relatively small water heads. As for the submarine tunnel with high water pressure of 100 meters, the "fully enclosed mode" cannot be used. The secondary lining of the tunnel in the "full drainage mode" basically does not bear water pressure, but its corresponding tunnel drainage volume is large, especially for long-distance submarine tunnels, the drainage cost during the operation period is very high; currently, the drainage cost is generally reduced by local grouting of water-rich surrounding rock sections to reduce the amount of water gushing behind the lining, but large-scale grouting is expensive, and the long-term durability of submarine tunnel grouting is also difficult to guarantee. For long-distance and high-water-pressure submarine tunnels, the drainage volume during the operation period is still large. The "limited drainage mode" is a solution between the "full closure mode" and the "full drainage mode". At present, relevant research is still insufficient, especially in the water pressure sensing and overpressure automatic control drainage technology and devices behind the tunnel secondary lining, there is a lack of relevant results.

[0003] With the development of intelligent construction and smart operation and maintenance technologies in my country in recent years, as well as the rapidly growing construction demand for high-water-pressure and long-distance submarine tunnels, the development of a drill-and-blast submarine tunnel drainage system with water pressure sensing and overpressure drainage capabilities is of great significance for ensuring the structural safety of high-water-pressure and long-distance submarine tunnels and reducing operating costs.

[0004] After searching, it was found that the Chinese invention patent with application publication number CN118757223A discloses a subsea tunnel drainage partition wall structure based on water pressure perception, including a longitudinal drainage ditch, in which a group of drainage partition walls are arranged, and the drainage partition walls divide the longitudinal drainage ditch into different partition intervals; a group of water pressure sensing drain valves are arranged in the longitudinal drainage ditch, and the drain valves are mainly composed of pressure control valves. Each pressure control valve is connected to its corresponding drain pipe, and the other end of the pipe passes through the tunnel lining structure through the drain hole and extends into the grouting layer. When the water pressure of the grouting layer reaches the water pressure sensing range, the corresponding pressure control valve opens, and the water enters the longitudinal drainage ditch to unload the excess water pressure around the main structure. The problem solved by this prior art is to have the ability to respond to emergencies when the drainage and drainage of the subsea tunnel fails or an emergency occurs. That is, it adds an emergency measure on the basis of the currently widely used drilling and blasting method subsea tunnel drainage and drainage system to prevent the lining from being subjected to excessive water pressure when the drainage and drainage system fails, and does not solve the above technical problems. Summary of the invention

[0005] In view of the defects in the prior art, the object of the present invention is to provide a drill and blast submarine tunnel drainage system and an implementation method thereof.

[0006] According to one aspect of the present invention, there is provided a drilling and blasting submarine tunnel waterproofing and drainage system, comprising:

[0007] The annular drainage mechanism includes an annular drainage pipe, wherein the annular drainage pipe is arranged in an annular direction on the initial support surface;

[0008] The longitudinal drainage mechanism includes a longitudinal drainage pipe and a tunnel drainage ditch. The longitudinal drainage pipe is arranged at the foot of the side walls on both sides of the tunnel lining and runs through the entire tunnel; the tunnel drainage ditch is arranged at the tunnel invert and runs through the entire tunnel;

[0009] A transverse drainage mechanism, comprising two transverse water diversion pipes respectively arranged on the left and right sides of the tunnel at the cross section, wherein one end of the two transverse water diversion pipes is respectively connected to the annular drainage pipe and the longitudinal drainage pipe, and the other end is connected to the tunnel drainage ditch;

[0010] The water pressure sensing and overpressure drainage mechanism comprises a water pressure gauge and an overpressure drainage device, wherein the water pressure gauge is used to measure the water pressure at the bottom of the tunnel, and the water pressure gauge is integrated on the overpressure drainage device; the overpressure drainage device is located between the two sections of the transverse water diversion pipe; the overpressure drainage device is connected to the end of the transverse water diversion pipe, and the overpressure drainage device is used to discharge groundwater in time when the water pressure exceeds a preset value.

[0011] Optionally, the annular drainage pipe adopts a single-wall perforated corrugated pipe, the annular drainage pipe is wrapped with a layer of geotextile, and the distance between two adjacent annular drainage pipes is 5 to 20m.

[0012] Optionally, the annular drainage mechanism further includes a composite waterproof layer, and the composite waterproof layer is arranged between the initial support and the secondary lining.

[0013] Optionally, the longitudinal drainage pipe is a double-wall perforated corrugated pipe, and the longitudinal drainage pipe is wrapped with a layer of geotextile.

[0014] Optionally, the tunnel drainage ditch uses a prefabricated concrete pipe, and the concrete pipe is partially opened with holes to be connected to the lateral water diversion pipe.

[0015] Optionally, the overpressure drainage device has a drainage hole. When the internal pressure of the lateral water diversion pipe is lower than a preset pressure relief value, the drainage hole is closed, and when the internal pressure of the lateral water diversion pipe is higher than the preset pressure relief value, the drainage hole is opened.

[0016] Optionally, the overpressure drainage device comprises:

[0017] An inner steel cylinder, the drainage hole is arranged on the inner steel cylinder, and a fixing bracket is arranged on the outer wall of the inner steel cylinder;

[0018] A round steel plate is located inside the inner steel cylinder, and the diameter of the round steel plate matches the inner diameter of the inner steel cylinder;

[0019] A spring, one end of which is connected to the circular steel plate;

[0020] A fixing rod is fixed to the open end of the inner steel cylinder, and the other end of the spring is connected to the fixing rod; the water pressure gauge is fixed to the fixing rod;

[0021] An outer steel cylinder is sleeved on the outside of the inner steel cylinder, and the outer steel cylinder is connected to the inner steel cylinder through the fixing bracket;

[0022] An external steel casing has one end fixedly connected to the end of the outer steel cylinder and the other end connected to the transverse water diversion pipe.

[0023] Optionally, the end of the transverse water diversion pipe is provided with a thread, and the thread is used to connect with the external steel casing of the overpressure drainage device.

[0024] Optionally, the distance between adjacent water pressure sensing and overpressure drainage mechanisms is 5 to 20 m.

[0025] According to another aspect of the present invention, there is provided a method for implementing the above-mentioned drill and blast method submarine tunnel waterproofing and drainage system, the method comprising:

[0026] According to the geological conditions and overall design of the tunnel, the water inflow is predicted in sections, and the preset water pressure value behind the lining is determined by combining the capacity of the tunnel water collection tank, the predicted water inflow of the tunnel and the structural calculation;

[0027] According to the preset water pressure value of the tunnel, a water pressure sensing and overpressure drainage mechanism is prefabricated, and threads are left at the ends of the overpressure drainage device to be connected to the lateral water diversion pipe;

[0028] According to the surrounding rock conditions of the tunnel, annular drainage pipes are laid on the initial support surface at intervals along the longitudinal direction of the tunnel;

[0029] Longitudinal drainage pipes are installed at the foot of the side walls on both sides of the tunnel lining in the longitudinal direction and connected to the annular drainage pipes with tees;

[0030] When pouring the tunnel invert, a transverse water diversion pipe is pre-buried, and the transverse water diversion pipe is connected to the longitudinal drainage pipe pre-buried at the foot of the side wall by a tee pipe;

[0031] Before backfilling the invert, the longitudinal tunnel drainage ditch and the water pressure sensing and overpressure drainage mechanism are pre-buried, and the tunnel drainage ditch is connected to the overpressure drainage device through a transverse water diversion pipe;

[0032] Connect the water pressure gauge cable to the tunnel monitoring system; when the monitored water pressure at a certain point in the tunnel exceeds the preset control water pressure value, repair it in time.

[0033] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0034] The drill-and-blast submarine tunnel drainage system provided by the present invention can automatically sense the water pressure behind the tunnel lining by setting a water pressure sensing and overpressure drainage mechanism, and can automatically drain water at overpressure when the water pressure exceeds a preset value. The drainage system has water pressure sensing and overpressure drainage capabilities, and can achieve limited discharge of groundwater in the drill-and-blast submarine tunnel, so that the water pressure behind the lining is always maintained within the preset water pressure range, and the tunnel drainage volume is reduced under the premise of ensuring the safety of the tunnel structure, so as to achieve precise control of the drainage during the operation period of the drill-and-blast submarine tunnel. In addition, by allowing the tunnel lining to withstand a certain water pressure, the pressure difference between the water pressure behind the lining and the external water head is reduced, the water seepage in the submarine tunnel is significantly reduced, and the drainage cost during the operation period is greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0036] Figure 1 It is a schematic cross-sectional structure diagram of a subsea tunnel drainage system using a drill and blast method with water pressure sensing and overpressure drainage capabilities in one embodiment of the present invention;

[0037] Figure 2 It is a structural schematic diagram of a water pressure sensing and overpressure drainage device in one embodiment of the present invention;

[0038] In the figure: 1 is the initial support, 2 is the annular drainage pipe, 3 is the composite waterproof layer, 4 is the secondary lining, 5 is the longitudinal drainage pipe, 6 is the transverse water diversion pipe, 7 is the tunnel drainage ditch, 8 is the overpressure drainage device, 9 is the external steel casing, 10 is the outer steel cylinder, 11 is the inner steel cylinder, 12 is the fixing rod, 13 is the spring, 14 is the round steel plate, 15 is the fixing bracket, 16 is the drainage hole, 17 is the water pressure gauge, 18 is the cable, and 19 is the embedded steel pipe. DETAILED DESCRIPTION

[0039] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0040] Reference Figure 1 , is a schematic diagram of the cross-sectional structure of a subsea tunnel waterproofing and drainage system using a drill and blast method provided by an embodiment of the present invention, wherein the dotted line in the figure indicates the tunnel centerline, and the waterproofing and drainage system includes an annular drainage mechanism, a longitudinal drainage mechanism, a transverse drainage mechanism, and a water pressure sensing and overpressure drainage mechanism, wherein: the annular drainage mechanism includes an annular drainage pipe 2, which is arranged annularly on the surface of the initial support 1; the longitudinal drainage mechanism includes a longitudinal drainage pipe 5 and a tunnel drainage ditch 7, the longitudinal drainage pipe 5 is arranged at the foot of the side walls on both sides of the tunnel lining, and the entire tunnel is connected; the tunnel drainage ditch 7 is arranged at the tunnel invert, and the entire tunnel is connected; the transverse drainage mechanism includes four sections of transverse water diversion pipes 6, which are respectively two sections of transverse water diversion pipes 6 arranged on the left and right sides of the tunnel at the section, and one end of the two sections of transverse water diversion pipes 6 is connected to the annular drainage pipe 2 and the longitudinal drainage pipe 5 through a three-way joint. The water pressure sensing and overpressure drainage mechanism comprises a water pressure gauge 17 and an overpressure drainage device 8. The water pressure gauge 17 is used to measure the water pressure at the bottom of the tunnel. The water pressure gauge 17 is integrated in the overpressure drainage device 8. The cable 18 of the water pressure gauge 17 is led out through the pre-buried steel pipe 19 and connected to the tunnel monitoring system. The overpressure drainage device 8 is located between two sections of transverse water diversion pipes 6, that is, overpressure drainage devices 8 are respectively provided between the two sections of transverse water diversion pipes 6 on the left side of the tunnel and between the two sections of transverse water diversion pipes 6 on the right side. The water pressure sensing and overpressure drainage mechanism comprises 2 water pressure gauges 17 and 2 sets of overpressure drainage devices 8, which are arranged throughout the tunnel. The overpressure drainage device 8 is connected to the end of the transverse water diversion pipe 6. The overpressure drainage device 8 is used to discharge groundwater in time when the water pressure exceeds the preset value, and does not drain water within the preset pressure value range.

[0041] In the embodiment of the present invention, the whole tunnel is connected in the length direction of the tunnel. The annular drainage pipe 2, the longitudinal drainage pipe 5 and the transverse water diversion pipe 6 are connected by a three-way joint. When the groundwater flows in the transverse water diversion pipe 6, it will pass through the overpressure drainage device 8. When the preset pressure relief value is exceeded, the overpressure drainage device 8 has a drainage hole. When the internal pressure of the transverse water diversion pipe is lower than the preset pressure relief value, the drainage hole is closed. When the internal pressure of the transverse water diversion pipe is higher than the preset pressure relief value, the drainage hole is opened, and the pipe body is unobstructed, thereby diverting water to the tunnel drainage ditch 7.

[0042] In the embodiment of the present invention, the overpressure drainage device 8 cooperates with the longitudinal drainage pipe 5, the transverse water diversion pipe 6, and the tunnel drainage ditch 7 to realize the drainage process. The specific process is as follows: the groundwater behind the lining is first drained to the longitudinal drainage pipe 5 through the annular drainage pipe 2, and the water is drained to the transverse water diversion pipe 6 through the longitudinal drainage pipe 5, and the transverse water diversion pipe 6 then drains the water to the tunnel drainage ditch 7.

[0043] The diameter and spacing of the annular drainage pipe 2 are determined according to the degree of crushing of the tunnel surrounding rock and the enrichment of groundwater. In some embodiments, the annular drainage pipe 2 adopts a single-wall perforated corrugated pipe, which is fixed on the initial support 1. For example, a Φ50HDPE single-wall perforated corrugated pipe is used, and the annular drainage pipe 2 is wrapped with a layer of geotextile. The spacing between two adjacent annular drainage pipes 2 is 5 to 20m. The horizontal water diversion pipe 6 has the same spacing as the annular drainage pipe 2, which is determined according to the geological conditions of the tunnel. It can be appropriately increased in the surrounding rock crushing section or water-rich section, and can be appropriately reduced in the surrounding rock section or water-poor section. In this way, the groundwater can be discharged smoothly.

[0044] In some embodiments, the annular drainage mechanism further includes a composite waterproof layer 3, which is disposed between the primary support 1 and the secondary lining 4. Exemplarily, the composite waterproof layer 3 includes a waterproof board and a non-woven fabric, which are adhered to each other and installed between the primary support 1 and the secondary lining 4.

[0045] In order to guide the water of the annular drainage pipe 2 into the transverse water diversion pipe 6 until it is discharged from the tunnel drainage ditch 7, in some embodiments, the longitudinal drainage pipe 5 is a double-wall perforated corrugated pipe. For example, one Φ110 HDPE double-wall perforated corrugated pipe is arranged along the longitudinal direction of the tunnel. Figure 1 There is a first longitudinal drainage pipe located on one side of the tunnel and a second longitudinal drainage pipe located on the other side, and the longitudinal drainage pipe 5 is wrapped with a layer of geotextile.

[0046] In some embodiments, the tunnel drainage ditch 7 is made of prefabricated concrete pipes, and one or two pipes can be appropriately selected according to the drainage volume of the tunnel, such as Figure 1The first tunnel drainage ditch on one side of the tunnel and the second tunnel drainage ditch on the other side are partially perforated with concrete pipes to connect with the transverse water diversion pipe 6. Inspection ports are set every 100m along the longitudinal direction of the tunnel to facilitate regular dredging and inspection of the tunnel drainage ditch 7.

[0047] In some embodiments, the transverse water diversion pipe 6 is a double-wall corrugated pipe. For example, the entire tunnel is provided with transverse Φ110HDPE double-wall corrugated pipes with a spacing of 5 to 20 m. The transverse water diversion pipe 6 is connected to the Φ110HDPE longitudinal double-wall perforated corrugated pipe pre-buried at the foot of the side wall by a tee, which connects the annular drain pipe 2, the longitudinal drain pipe 5 and one end of the transverse water diversion pipe 6, connecting the longitudinal drain pipe 5, the water pressure sensing and overpressure drainage mechanism, and the tunnel drainage ditch 7.

[0048] Reference Figure 2 In some embodiments, the overpressure drainage device 8 includes an external steel casing 9, an inner steel cylinder 11, an outer steel cylinder 10, a spring 13, a fixing rod 12, a fixing bracket 15, a round steel plate 14, and a drainage hole 16. The inner steel cylinder 11 is provided with a drainage hole 16, and the outer wall of the inner steel cylinder 11 is provided with a fixing bracket 15; the round steel plate 14 is located inside the inner steel cylinder 11, and the diameter of the round steel plate 14 matches the inner diameter of the inner steel cylinder 11; one end of the spring 13 is connected to the round steel plate 14; the fixing bracket 15 is provided on the outer wall of the inner steel cylinder 11; the round steel plate 14 is located inside the inner steel cylinder 11, and the diameter of the round steel plate 14 matches the inner diameter of the inner steel cylinder 11; one end of the spring 13 is connected to the round steel plate 14; The fixed rod 12 is fixed to the open end of the inner steel cylinder 11, and the other end of the spring 13 is connected to the fixed rod 12; the water pressure gauge 17 is fixed to the fixed rod 12; the outer steel cylinder 10 is sleeved on the outside of the inner steel cylinder 11, and the outer steel cylinder 10 is connected to the inner steel cylinder 11 through a fixed bracket 15. The outer steel cylinder 10 is provided with a wiring hole for the cable 18 of the water pressure gauge 17 to pass through; one end of the external steel casing 9 is fixedly connected to the end of the outer steel cylinder 10, and the other end is connected to the horizontal water diversion pipe 6.

[0049] The manufacturing process of the overpressure drainage device 8 is as follows: (1) a drainage hole 16 is opened at a specified position on the inner steel cylinder 11, and a fixing bracket 15 is welded on the inner steel cylinder 11; (2) the fixing rod 12, the spring 13, and the round steel plate 14 are made into a whole and placed in the inner steel cylinder 11, and the fixing rod 12 and the inner steel cylinder 11 are welded and fixed; the water pressure gauge 17 is fixed on the fixing rod 12; (3) a wiring hole is reserved on the outer steel cylinder 10 (for the cable 18 of the water pressure gauge 17 to pass through); the inner steel cylinder 11 and the outer steel cylinder 10 are welded and fixed by the fixing bracket 15; the external steel casing 9 is welded to the outer steel cylinder 10; (4) the horizontal water pipe 6 is connected to the external steel casing.

[0050] In the above-mentioned embodiment of the present invention, groundwater enters the water pressure sensing and overpressure drainage mechanism through the transverse water diversion pipe 6, and the water pressure acts on the built-in circular steel plate 14; when the water pressure is greater than the preset pressure relief value, the circular steel plate 14 will slide along the inner steel cylinder 11 under the action of the water pressure, and the greater the water pressure, the longer the sliding distance; within the sliding corresponding range, that is, the opening range, the inner steel cylinder 11 is provided with a drainage hole 16, and the overpressure water is discharged to the outer steel cylinder 10 through the drainage hole 16, and the range and size of the drainage hole 16 are determined according to the preset pressure relief value, the predicted water gushing amount, the stiffness of the spring 13, etc.; then the overpressure water is led to the transverse water diversion pipe 6 through the external steel casing 9 until it reaches the tunnel drainage ditch 7.

[0051] In some embodiments, the end of the transverse water diversion pipe 6 is provided with threads, and the threads are used to connect with the external steel casing 9 of the overpressure drainage device 8.

[0052] The water pressure sensing and overpressure drainage mechanisms correspond to the positions of the transverse water diversion pipes 6 along the length of the tunnel. In some embodiments, the spacing between adjacent water pressure sensing and overpressure drainage mechanisms is 5 to 20 m.

[0053] The drainage system for the drill-and-blast submarine tunnel provided by the above-mentioned embodiment of the present invention can automatically sense the water pressure behind the tunnel lining by setting a water pressure sensing and overpressure drainage mechanism, and can automatically drain water at overpressure when the water pressure exceeds a preset value. The drainage system has the ability to sense water pressure and drain water at overpressure, and can achieve limited discharge of groundwater in the drill-and-blast submarine tunnel, so that the water pressure behind the lining is always maintained within the preset water pressure range, reduce the tunnel drainage volume while ensuring the safety of the tunnel structure, and achieve precise control of the drainage during the operation period of the drill-and-blast submarine tunnel, thereby reducing the drainage costs during the operation period. In addition, by allowing the tunnel lining to withstand a certain water pressure, the pressure difference between the water pressure behind the lining and the external water head is reduced, the water seepage in the submarine tunnel is significantly reduced, and the drainage costs during the operation period are greatly reduced.

[0054] The above-mentioned embodiment of the present invention constructs a new type of drilling and blasting submarine tunnel waterproofing and drainage system, which can achieve the following objectives:

[0055] (1) By allowing the tunnel lining to withstand a certain amount of water pressure, the pressure difference between the water pressure behind the lining and the external water head can be reduced, which can significantly reduce the amount of water seepage in the submarine tunnel and greatly reduce the drainage costs during the operation period; it can also reduce the grouting range and reduce the grouting costs.

[0056] (2) By using the overpressure drainage device 8 to achieve overpressure drainage, the limited discharge of groundwater in the drill-and-blast submarine tunnel can be achieved, so that the water pressure behind the lining is always kept within the preset water pressure range; that is, when the water pressure behind the lining at a certain point is lower than the preset pressure relief value, it can be ensured that no drainage is done; when it is higher than the preset pressure relief value, the overpressure drainage device 8 at the corresponding position automatically discharges the pressurized water exceeding the preset pressure, ensuring that the water pressure is always controlled within a certain range during operation;

[0057] (3) The environment of submarine tunnels is complex. The traditional mode of reducing water inflow by grouting and blocking water has the risk of grout being corroded by seawater and lost, resulting in increased tunnel drainage. The waterproofing and drainage system in the above embodiment of the present invention can effectively reduce this risk.

[0058] (4) The water pressure gauge 17 can be used to automatically sense the water pressure behind the lining, and the overpressure drainage device 8 can be replaced and repaired when an abnormality occurs.

[0059] Based on the same inventive concept, another embodiment of the present invention provides an implementation method of the above-mentioned drilling and blasting method submarine tunnel waterproofing and drainage system, the method comprising:

[0060] S1. According to the geological conditions and overall design of the tunnel, the water inflow is predicted in sections, and the capacity of the tunnel water collection pool, the predicted water inflow of the tunnel and the structural calculation are comprehensively considered to determine the preset water pressure value behind the lining, which serves as a prerequisite for the subsequent prefabrication of water pressure sensing and overpressure drainage mechanisms. For example, the opening range of the drainage holes and the stiffness of the springs are determined accordingly.

[0061] S2. Prefabricate a batch of water pressure sensing and overpressure drainage mechanisms according to the preset water pressure value of the tunnel, and leave threads at the ends of the overpressure drainage devices to connect with the lateral water diversion pipes;

[0062] S3. According to the surrounding rock conditions of the tunnel, an annular drainage pipe is laid on the initial support surface at intervals along the longitudinal direction of the tunnel; for example, an annular Φ50 HDPE single-wall perforated corrugated pipe is laid on the initial support surface at intervals of 5 to 20 m along the longitudinal direction of the tunnel;

[0063] S4. Longitudinal drainage pipes (such as Φ110 HDPE double-wall perforated corrugated pipes) are installed at the foot of the side walls on both sides of the tunnel lining, and connected to the annular drainage pipes with tees;

[0064] S5. When pouring the tunnel invert, a double-wall corrugated pipe (such as Φ110 HDPE double-wall corrugated pipe) is pre-buried as a transverse water diversion pipe, and the transverse water diversion pipe is connected to the longitudinal drainage pipe pre-buried at the foot of the side wall with a tee pipe;

[0065] S6. Before backfilling the invert, the longitudinal tunnel drainage ditch and the water pressure sensing and overpressure drainage mechanism are pre-buried, and the tunnel drainage ditch is connected to the overpressure drainage device through a transverse water diversion pipe;

[0066] S7. Lead the cables of the water pressure gauges in the water pressure sensing and overpressure drainage mechanism through the pre-buried steel pipe and connect them to the tunnel monitoring system; when the monitored water pressure at a certain point in the tunnel exceeds the preset control water pressure value, repair it in time.

[0067] In some embodiments, after step S4, the method further includes: between the initial lining support and the secondary lining, except for the invert, the entire area is fully covered with a composite waterproof layer. Exemplarily, the composite waterproof layer is a waterproof board with non-woven fabric.

[0068] It should be noted that the method in the embodiment of the present invention and the system embodiment are based on the same inventive concept, and the specific process is detailed in the system embodiment. The method embodiment has the same beneficial effects as the system embodiment, which will not be repeated here.

[0069] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various modifications or variations within the scope of the claims, which does not affect the essence of the present invention. The above preferred features can be used in any combination without conflicting with each other.

Claims

1. A drilling and blasting submarine tunnel drainage system, characterized in that: include: The annular drainage mechanism includes an annular drainage pipe, wherein the annular drainage pipe is arranged in an annular direction on the initial support surface; The longitudinal drainage mechanism includes a longitudinal drainage pipe and a tunnel drainage ditch. The longitudinal drainage pipe is arranged at the foot of the side walls on both sides of the tunnel lining and runs through the entire tunnel; the tunnel drainage ditch is arranged at the tunnel invert and runs through the entire tunnel; A transverse drainage mechanism, comprising two transverse water diversion pipes respectively arranged on the left and right sides of the tunnel at the cross section, wherein one end of the two transverse water diversion pipes is respectively connected to the annular drainage pipe and the longitudinal drainage pipe, and the other end is connected to the tunnel drainage ditch; The water pressure sensing and overpressure drainage mechanism comprises a water pressure gauge and an overpressure drainage device, wherein the water pressure gauge is used to measure the water pressure at the bottom of the tunnel, and the water pressure gauge is integrated on the overpressure drainage device; the overpressure drainage device is located between the two sections of the lateral water diversion pipes, and the overpressure drainage device is connected to the ends of the lateral water diversion pipes, and the overpressure drainage device is used to discharge groundwater in time when the water pressure exceeds a preset value.

2. The drill-and-blast submarine tunnel drainage system according to claim 1 is characterized in that: The annular drainage pipe adopts a single-wall perforated corrugated pipe, and a layer of geotextile is wrapped outside the annular drainage pipe. The distance between two adjacent annular drainage pipes is 5 to 20 meters.

3. The drill-and-blast submarine tunnel drainage system according to claim 1 is characterized in that: The annular drainage mechanism also includes a composite waterproof layer, which is arranged between the initial support and the secondary lining.

4. The drill-and-blast submarine tunnel drainage system according to claim 1, characterized in that: The longitudinal drainage pipe is a double-wall perforated corrugated pipe, and the longitudinal drainage pipe is wrapped with a layer of geotextile.

5. The drill-and-blast submarine tunnel drainage system according to claim 1, characterized in that: The tunnel drainage ditch adopts prefabricated concrete pipes, and the concrete pipes are partially opened to connect with the transverse water diversion pipes.

6. The drill-and-blast submarine tunnel drainage system according to claim 1, characterized in that: The overpressure drainage device has a drainage hole. When the internal pressure of the lateral water diversion pipe is lower than the preset pressure relief value, the drainage hole is closed. When the internal pressure of the lateral water diversion pipe is higher than the preset pressure relief value, the drainage hole is opened.

7. The drill-and-blast submarine tunnel drainage system according to claim 6, characterized in that: The overpressure drainage device comprises: An inner steel cylinder, the drainage hole is arranged on the inner steel cylinder, and a fixing bracket is arranged on the outer wall of the inner steel cylinder; A round steel plate is located inside the inner steel cylinder, and the diameter of the round steel plate matches the inner diameter of the inner steel cylinder; A spring, one end of which is connected to the circular steel plate; A fixing rod is fixed to the open end of the inner steel cylinder, and the other end of the spring is connected to the fixing rod; the water pressure gauge is fixed to the fixing rod; An outer steel cylinder is sleeved on the outside of the inner steel cylinder, and the outer steel cylinder is connected to the inner steel cylinder through the fixing bracket; An external steel casing has one end fixedly connected to the end of the outer steel cylinder and the other end connected to the transverse water diversion pipe.

8. The drill-and-blast submarine tunnel drainage system according to claim 7, characterized in that: The end of the transverse water diversion pipe is provided with a thread, and the thread is used to be connected to the external steel casing of the overpressure drainage device.

9. The drill-and-blast submarine tunnel drainage system according to claim 1, characterized in that: The distance between adjacent water pressure sensing and overpressure drainage mechanisms is 5 to 20 meters.

10. A method for implementing the drill-and-blast submarine tunnel drainage system according to any one of claims 1 to 9, characterized in that: include: According to the geological conditions and overall design of the tunnel, the water inflow is predicted in sections, and the preset water pressure value behind the lining is determined by combining the capacity of the tunnel water collection tank, the predicted water inflow of the tunnel and the structural calculation; According to the preset water pressure value of the tunnel, a water pressure sensing and overpressure drainage mechanism is prefabricated, and threads are left at the ends of the overpressure drainage device to be connected to the lateral water diversion pipe; According to the surrounding rock conditions of the tunnel, annular drainage pipes are laid on the initial support surface at intervals along the longitudinal direction of the tunnel; Longitudinal drainage pipes are installed at the foot of the side walls on both sides of the tunnel lining in the longitudinal direction and connected to the annular drainage pipes with tees; When pouring the tunnel invert, a transverse water diversion pipe is pre-buried, and the transverse water diversion pipe is connected to the longitudinal drainage pipe pre-buried at the foot of the side wall by a tee pipe; Before backfilling the invert, the longitudinal tunnel drainage ditch and the water pressure sensing and overpressure drainage mechanism are pre-buried, and the tunnel drainage ditch is connected to the overpressure drainage device through a transverse water diversion pipe; Connect the water pressure gauge to the tunnel monitoring system; when the monitored water pressure at a certain point in the tunnel exceeds the preset control water pressure value, repair it in time.

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