A dynamic sequential grouting method for ultra-high temperature hot water tunnels

Abstract

The present invention discloses a method for dynamic sequential grouting in a super-high temperature hot water tunnel. The existing construction efficiency of super-high temperature hot water tunnels is low, and the gushing of super-high temperature hot water endangers the safety of operators. In the present invention, an advanced horizontal drill is constructed at the tunnel face for detection. Through the top water grouting of the horizontal drill, the total water output of the deepened blast holes at the face is tested. When the water-bearing operation standard is not met, sequential dynamic grouting is carried out. Grouting holes are constructed around the face, orifice pipes are set at the drilling positions, and water stoppers are installed at the ends of the grouting holes. The present invention uses the subsequent holes as the effect inspection of the pre-sequence grouting completion holes, which speeds up the grouting construction efficiency; during the drilling process, low-temperature cold water is injected through the ball valve to fuse the high-temperature hot water, reducing the hot water temperature in the tunnel drilling; after the drill tool is withdrawn, the high-temperature waterproof gate valve can be closed in time, and grouting is carried out through the wall ball valve in time to block water, speeding up the construction progress and ensuring complete construction.

Description

Technical Field

[0001] The present invention belongs to the technical field of ultra-high temperature tunnel engineering construction, and particularly relates to a dynamic sequential grouting method for ultra-high temperature hot water tunnels. Background Art

[0002] In ultra-high temperature hot water tunnels, when the surrounding rock temperature of the tunnel body is about 80 °C and the relative humidity reaches more than 80%, the high geothermal problem will become particularly prominent. The high temperature and humidity will deteriorate the construction environment in the tunnel, seriously threatening the health and safety of construction workers, affecting the tunnel construction progress, and increasing the tunnel construction safety risk.

[0003] Since the excavation of the tunnel will cause a certain degree of relaxation of the original stress of the surrounding rock or the surrounding rock itself has developed joints, the surrounding rock will deform and generate cracks. Groundwater and surface water follow the law of infiltration, replenishment, and drainage from high-pressure areas to low-pressure areas, and form a water flow seepage field and a circulation system along the cracks in the surrounding rock. Since the tunnel excavation space is at the center of the circulation system, conditions are created for tunnel leakage. The leakage phenomenon in ultra-high temperature hot water tunnels seriously affects the service life and safety of the tunnel. However, when using the conventional grouting method for plugging leakage in tunnels for drilling, generally full-face grouting is adopted, with extremely low construction efficiency and high cost; and when drilling, ultra-high temperature hot water gushes out, endangering the safety of operators. Summary of the Invention

[0004] In order to make up for the deficiencies of the prior art, the present invention provides a dynamic sequential grouting method for ultra-high temperature hot water tunnels, which has high construction efficiency, high safety, and good control of the tunnel environment.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A dynamic sequential grouting method for ultra-high temperature hot water tunnels includes the following steps:

[0007] Step 1: Conduct detection by constructing an advanced horizontal drill at the tunnel face, and the advanced horizontal drill is arranged at the center of the tunnel;

[0008] Step 2: When the water output and temperature of the advanced horizontal drill are greater than a certain heat energy, grout while pushing water through the advanced horizontal drill;

[0009] Step 3: After grouting while pushing water, continue to excavate the tunnel, and add deeper blast holes in front of the face first;

[0010] Step 4: Test the total water output of the deeper blast holes at the face. When the total water output of the deeper blast holes does not meet the standard for water-carrying operation, conduct sequential dynamic grouting, which specifically includes the following steps:

[0011] S4.1: Seal the face with concrete and build a drilling rig platform;

[0012] S4.2: Peripheral grouting holes are constructed on the heading face. An orifice pipe is set at the drilling position, and a water stop is installed at the end of the grouting hole.

[0013] S4.3: The subsequent grouting holes also serve as inspection holes for the previous grouting holes. When the water inflow during the drilling of the subsequent grouting holes meets the requirements of the inspection holes, the grouting construction is terminated until a closed reinforcement ring is formed.

[0014] Furthermore, the grouting holes are constructed in the order of "from outside to inside, first down then up, in sequences, and with interval skip holes", and are set within a range of 3 - 5 m outside the tunnel contour line.

[0015] It includes multiple grouting hole rings. The previous grouting hole rings are set on the outside of the subsequent grouting hole rings. The first - order grouting hole ring is set on the outermost layer of the grouting range. The second - order grouting hole ring is set inside the first - order grouting hole ring, and the third - order grouting hole ring is set inside the second - order grouting hole ring, and so on. The number of grouting hole rings is set according to the actual needs of the project. Multiple - order grouting holes are set on each grouting hole ring. Each order of grouting holes includes multiple grouting holes. The subsequent grouting holes are set at intervals between the previous grouting holes. The trajectory formed by the centers of the grouting holes on each grouting hole ring is consistent with the tunnel contour line.

[0016] Furthermore, the orifice pipe is fixedly installed at the grouting hole drilling position through a flange. The flange is fixedly connected to one end of the steel pipe. A ball valve is fixedly connected to the steel pipe body through a single - wire joint.

[0017] The drill bit to the drill pipe part of the water stop is set inside the steel pipe of the orifice pipe, and the drill bit is set at the end of the grouting hole.

[0018] A check valve is set at one end of the drill pipe connected to the drill bit. The other end of the drill pipe is connected to a pipe body through a flange, and the other end of the pipe body is connected to a three - way diverter through a flange.

[0019] A high - temperature and high - pressure gate valve is connected to the pipe body. An automatic control butterfly valve is connected to the three - way diverter, and a slag discharge port is set at the other end of the automatic control butterfly valve.

[0020] Furthermore, the deepening blast holes are set around the tunnel, with 10 holes, a length of 6 m, an outward - inclined angle of 10 degrees, and a drilling diameter of 64 mm.

[0021] Furthermore, the specific content of step S4.1 is as follows:

[0022] a) The heading face is closed and leveled by hanging a double - layer Φ8 steel mesh and spraying 30 cm thick C30 concrete, and the heading face bolts are connected to the steel mesh. The bolts are 3 m long and arranged in a 1.5 m diamond pattern.

[0023] b) The length of the drill rig platform is 9 m, and the top surface is 6 m away from the top of the primary support arch. The platform is cast with 10 cm thick C25 concrete.

[0024] Further, in the fourth step, the sequential dynamic grouting is carried out according to the constrained grouting. Combining the formation characteristics, the segmented progressive grouting is adopted to block water, and the size of the water inflow from the borehole is used as the segmentation standard: ① When the water inflow from the borehole is no more than 5 m 3 / h, grouting is carried out after the borehole reaches the end hole; ② When the water inflow from the borehole is 5 - 10 m 3 / h, the segmented distance is 10 - 15 m; ③ When the water inflow from the borehole is 10 - 30 m 3 / h, the segmented distance is 5 - 10 m; ④ When the water inflow from the borehole is greater than 30 m 3 / h, grouting is carried out immediately after stopping the drilling; specifically, it is determined according to the water inflow from the borehole on site.

[0025] Advantages of the present invention:

[0026] 1) The grouting holes of the present invention are constructed in sequence, and the subsequent holes are used to check the effect of the previously grouted holes, which improves the grouting construction efficiency;

[0027] 2) During the drilling process of the present invention, low-temperature cold water is injected through the ball valve to fuse with the high-temperature hot water, reducing the temperature of the hot water in the tunnel borehole; after the drill tool is withdrawn, the high-temperature waterproof gate valve can be closed in time, and grouting can be carried out in time through the ball valve on the pipe wall to block water, accelerating the construction progress; minimizing the contact between personnel and high-temperature hot water to ensure safe construction;

[0028] 3) The present invention automatically controls the remote switch of the butterfly valve to automatically control the discharge amount of high-temperature water in the borehole; the high-temperature hot water and drill cuttings generated during drilling are discharged to the hot water collection and slag collection pool in front of the face through the slag discharge port, and flow out of the tunnel through the hot water drainage ditch and drainage pipe; effectively sealing and controlling the heat source, reducing the environmental temperature, and preventing risks such as personnel burns caused by the gushing of high-temperature hot water;

[0029] 4) The present invention has high construction efficiency, short construction period and high safety. According to the water discharge segmentation standard during the hole-making process and the drainage requirements of the special drainage pipeline set in the tunnel in advance, the single-hole grouting section length of each sequence hole can be dynamically adjusted, with flexible operation and easier control of the grouting and water-blocking construction quality. Description of the Drawings

[0030] Figure 1 It is the longitudinal section diagram of the sequential dynamic grouting of the present invention;

[0031] Figure 2 It is the cross-sectional diagram of the sequential dynamic grouting of the present invention;

[0032] Figure 3 It is the structural diagram of the sequential dynamic grouting hole of the present invention;

[0033] Figure 4 It is the schematic diagram of the hole mouth pipe structure of the present invention;

[0034] Figure 5 This is the water stop device of the present invention;

[0035] In the figure, 1 - advanced horizontal drill, 2 - drill rig platform, 3 - heading face, 4 - heading face bolt, 5 - deepened blast hole, 6 - tunnel contour line, 7 - grouting hole, 701 - first - order grouting hole ring, 702 - second - order grouting hole ring, 8 - orifice pipe, 9 - water stop device, 10 - hot water collection and slag pool, 11 - hot water drainage ditch, 12 - hot water drain pipe, 801 - steel pipe, 802 - flange, 803 - single - wire joint, 804 - ball valve, 901 - drill bit, 902 - drill pipe, 903 - check valve, 904 - pipe body, 905 - three - way flow - guide device, 906 - high - temperature and high - pressure gate valve, 907 - automatic control butterfly valve, 908 - slag discharge port, 909 - sealing sleeve. Specific embodiments

[0036] The present invention will be described in detail below in conjunction with specific embodiments.

[0037] A dynamic sequential grouting method for ultra - high - temperature hot water tunnels includes the following steps:

[0038] Step 1: As Figure 1 shown, an advanced horizontal drill 1 is constructed at the tunnel heading face for detection. The advanced horizontal drill 1 is arranged at the center of the tunnel; the drilling length of the advanced horizontal drill 1 is 50 m, the diameter is 65 mm, and the external insertion angle and upward inclination angle are both 0 degrees;

[0039] Step 2: When the water output and temperature of the advanced horizontal drill 1 are greater than a certain heat energy, grouting is carried out by pushing water through the advanced horizontal drill 1;

[0040] Step 3: After pushing - water grouting, continue to excavate the tunnel. Before excavation, deepened blast holes 5 are added at the heading face first, as Figure 2 shown; the deepened blast holes 5 are arranged around the tunnel. 10 holes are set, the length is 6 m, the external insertion angle is 10 degrees, and the drilling diameter is 64 mm;

[0041] Step 4: Test the total water output of the deepened blast holes 5 at the heading face. When the total water output of the deepened blast holes 5 does not meet the standard of water - carrying operation and the heat energy released per hour is greater than 1000 kW, sequential dynamic grouting is carried out, which specifically includes the following steps:

[0042] S4.1: Seal the heading face 3 with concrete and build a drill rig platform 2, specifically:

[0043] a) The heading face 3 is sealed and leveled by hanging a double - layer Φ8 steel mesh and spraying 30 cm thick C30 concrete, and is connected to the steel mesh with heading face bolts 4. The bolts are 3 m long and arranged in a plum - blossom pattern with a spacing of 1.5 m;

[0044] b) The length of the drilling rig platform 2 is 9 m, and the height from the top surface to the top of the primary support arch is 6 m. The platform is cast with 10 cm thick C25 concrete, which is conducive to the movement and operation of the drilling rig and speeds up the construction progress;

[0045] S4.2: Grouting holes 7 are constructed around the tunnel face 3, an orifice pipe 8 is set at the drilling position, and a water stop 9 is installed at the end of the grouting hole 7;

[0046] a) Grouting holes

[0047] The grouting holes 7 are constructed in the order of "from outside to inside, first down then up, in sequence, and with staggered holes". Specifically, the construction shall be carried out according to the actual working conditions. Generally, the grouting reinforcement range is 20 - 30 m in front of the tunnel face 3, and the reinforcement thickness is 3 - 5 m outside the tunnel contour line 6;

[0048] It includes multiple grouting hole rings. The previous grouting hole rings are set on the outside of the subsequent grouting hole rings. The first - order grouting hole ring is set on the outermost layer of the grouting range. The second - order grouting hole ring is set inside the first - order grouting hole ring, and the third - order grouting hole ring is set inside the second - order grouting hole ring, and so on. The number of grouting hole rings is set according to the actual engineering needs; Multiple - order grouting holes are set on each grouting hole ring. Each order of grouting holes includes multiple grouting holes, and the subsequent grouting holes are staggered between the previous grouting holes; The trajectory formed by the centers of the grouting holes on each grouting hole ring is consistent with the tunnel contour line 6;

[0049] As Figure 3 shown, in this embodiment, it includes a first - order grouting hole ring 701 and a second - order grouting hole ring 702. The first - order grouting hole ring 701 is set on the outside of the second - order grouting hole ring 702;

[0050] On the first - order grouting hole ring 701, there are first - order grouting holes, second - order grouting holes, and third - order grouting holes; The first - order grouting holes include 5 grouting holes, and the grouting holes are staggered; The second - order grouting holes are staggered between the first - order grouting holes; The third - order grouting holes are staggered between the first - order grouting holes and the second - order grouting holes;

[0051] On the second - order grouting hole ring 702, there are fourth - order grouting holes and fifth - order grouting holes; The fourth - order grouting holes include 5 grouting holes, and the grouting holes are staggered; The fourth - order grouting holes are staggered between the fifth - order grouting holes.

[0052] b) Orifice pipe

[0053] The orifice pipe 8 is fixedly installed at the drilling position of the grouting hole through a flange 802. The part from the drill bit 901 to the drill pipe 902 of the water stop 9 is set inside the steel pipe 801 of the orifice pipe 8, and the drill bit 901 is set at the end of the grouting hole;

[0054] As Figure 4As shown in the figure, the orifice pipe 8 includes a steel pipe 801, a flange 802, a monofilament joint 803 and a ball valve 804. The flange 802 is fixedly connected to one end of the steel pipe 801, and the ball valve 804 is connected to the steel pipe 801 through the monofilament joint 803. The steel pipe 801 is made of seamless steel pipe with a diameter of Φ108mm and a wall thickness of 4.5mm. The monofilament joint 803 is welded to the steel pipe 801. The processing and welding quality of the orifice pipe must be stable and reliable to avoid safety incidents such as the explosion of the orifice pipe weld and injury to people under the working conditions of high-pressure grouting.

[0055] c) Water stopper

[0056] As Figure 5 shown in the figure, the water stopper 9 includes a drill bit 901 and a drill pipe 902. A check valve 903 is provided at one end of the drill pipe 902 connected to the drill bit 901. The other end of the drill pipe 902 is connected to a pipe body 904 through a flange. The other end of the pipe body 904 is connected to a three-way diverter 905 through a flange. A high-temperature and high-pressure gate valve 906 is connected to the pipe body 904.

[0057] A self-control butterfly valve 907 is connected to the three-way diverter 905, and a slag discharge port 908 is provided at the other end of the self-control butterfly valve 907.

[0058] The other end of the three-way diverter 905 is connected to other pipe bodies through a flange. A sealing sleeve 909 is provided on the pipe body, which effectively ensures the connection between the drill pipe and the external drilling rig and can control and block the outflow of groundwater at the same time. The self-control butterfly valve 907 has a remote control switch to automatically control the discharge amount of high-temperature water in the drill hole and effectively control the heat source.

[0059] The orifice pipe 8 adopts a pre-buried process method of wrapping with hemp rope + expansion bolts (chemical bolts or chemical anchor bolts) + cement-based materials at the front end, which ensures that the orifice pipe is firmly installed, dense and does not leak water or slurry. Before the orifice pipe 8 is buried, the cement-based anchoring agent should be filled into the entire pipe at least 0.5h in advance, and the hemp rope should be wrapped around the part about 50cm away from the pipe orifice. The water stopper 9 is installed at the end of the grouting hole, and the part from the drill bit to the drill pipe of the water stopper 9 is arranged in the orifice pipe. During the drilling process, low-temperature cold water is injected through the ball valve 804 to mix with the high-temperature hot water in the water stopper 9 to reduce the hot water temperature. After the drill tool is withdrawn, the high-temperature and high-pressure gate valve 906 can be closed in time, and grouting can be carried out through the ball valve 804 in time to block water, thus accelerating the construction progress.

[0060] High-temperature hot water and drilling slag flow through the three-way diverter 905, the automatic control butterfly valve 907, and the slag discharge port 908 and are discharged into the hot water collection and slag collection pool 10 in front of the heading face. The size of the collection pool is 40*40 cm, and it flows along the slope towards the side wall and flows out of the tunnel through the hot water drainage ditch 11 and the drainage pipe 12. The size of the drainage ditch is 30*30 cm, and the drainage pipe is a 150-mm insulation pipe; the water output sectional standard during the construction of this drainage system and the drilling process can dynamically adjust the sectional length of each single-hole grouting section of each sequence hole, with flexible operation and easier control of the grouting water plugging construction quality.

[0061] S4.3: The subsequent grouting holes also serve as inspection holes for the previous grouting holes. According to the water plugging situation revealed by the subsequent inspection holes, the plan is dynamically optimized; after the construction of the previous grouting holes is completed, inspection methods such as the drilling detection of the water inflow of the inspection holes, the analysis method of the slurry filling rate, and borehole imaging are used for inspection. When the water inflow during the drilling of the subsequent holes meets the requirements of the inspection holes, the grouting construction is terminated until a closed reinforcement ring is formed.

[0062] The sequential dynamic grouting is carried out according to the constrained grouting. Combining the formation characteristics, the sectional advancing grouting is used to plug water, and the water inflow of the drilling hole is used as the sectional standard: ① When the water inflow of the drilling hole is not more than 5m 3 / h, grout after the drilling reaches the bottom hole; ② When the water inflow of the drilling hole is 5-10m 3 / h, the sectional distance is 10-15m; ③ When the water inflow of the drilling hole is 10-30m 3 / h, the sectional distance is 5-10m; ④ When the water inflow of the drilling hole is more than 30m 3 / h, stop drilling and start grouting immediately. It is specifically determined according to the water inflow of the drilling hole on-site.

[0063] For the sequential dynamic grouting, the grouting material with better economy is used, mainly "ordinary cement single liquid slurry and supplemented by cement-sodium silicate double liquid slurry". The mixing ratios of the ordinary cement slurry single liquid slurry are 1.5:1, 1:1, and 0.6:1; the water-cement ratios of the ordinary cement double liquid slurry are 0.8:1 and 0.6:1, and the sodium silicate content is 15% (mass ratio). The grouting mixing ratio is determined according to the water output in the hole, and specific on-site tests are carried out for adaptive adjustment. The grouting pressure is controlled at 5-6 MPa. When the grouting pressure reaches the designed final grouting pressure and is maintained for 5-10 minutes, the grouting of this hole can be terminated.

[0064] After the grouting of all the sequential dynamic grouting holes 7 in each cycle is completed, inspection holes are set near the main water outlet points to detect the water inflow in the holes. It is required that the water inflow of the inspection holes does not exceed 1-2 L / m·min for the grouting to be qualified; otherwise, supplementary hole grouting should be carried out; the slurry filling rate is analyzed using the grouting P-Q-t curve, and the slurry filling rate above 80% is regarded as qualified for grouting; a borehole imaging instrument is used to observe the hole formation situation and the slurry distribution situation of the inspection holes.

[0065] In the description of the present invention, unless otherwise clearly defined and limited, the terms "arranged", "installed", "connected", "coupled", "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0066] The content of the present invention is not limited to the examples listed. Any equivalent transformation of the technical solution of the present invention made by those of ordinary skill in the art by reading the specification of the present invention is covered by the claims of the present invention.

Claims

1. A dynamic sequential grouting method for ultra-high temperature hot water tunnels, characterized in that: It includes the following steps: Step 1: Conduct detection by constructing an advanced horizontal drill (1) at the tunnel face. The advanced horizontal drill (1) is arranged at the center of the tunnel; Step 2: Inject grout with water through the advanced horizontal drill (1); Step 3: Continue to excavate the tunnel after injecting grout with water. Before excavation, additional deepening blast holes (5) are added at the face first; Step 4: Test the total water output of the deepening blast holes (5) at the face. When the total water output of the deepening blast holes (5) does not meet the standard for water-bearing operation, sequential dynamic grouting is carried out, which specifically includes the following steps: S4.1: Seal the face (3) with concrete and build a drilling rig platform (2); S4.2: Construct grouting holes (7) around the face (3). A hole mouth pipe (8) is set at the drilling position, and a water stop device (9) is installed at the end of the grouting hole (7); S4.3: The subsequent grouting holes also serve as inspection holes for the previous grouting holes. When the water output during drilling of the subsequent grouting holes meets the requirements of the inspection holes, the grouting construction is terminated until a closed reinforcement ring is formed; The grouting holes (7) are constructed in accordance with the principle of "from outside to inside, first down then up, sequential construction, and staggered holes at intervals", and are arranged within the range of 3 - 5 m outside the tunnel contour line (6); It includes multiple grouting hole rings. The previous grouting hole rings are arranged outside the subsequent grouting hole rings. The first - order grouting hole ring is arranged on the outermost layer of the grouting range. A second - order grouting hole ring is arranged inside the first - order grouting hole ring, and a third - order grouting hole ring is arranged inside the second - order grouting hole ring, and so on. The number of grouting hole rings is set according to the actual engineering needs; Multiple - order grouting holes are set on each grouting hole ring. Each order of grouting holes includes multiple grouting holes, and the subsequent grouting holes are arranged at intervals between the previous grouting holes; The trajectory formed by the centers of the grouting holes on each grouting hole ring is consistent with the tunnel contour line (6); The hole mouth pipe (8) is fixedly installed at the grouting hole drilling position through a flange plate (802). The flange plate (802) is fixedly connected to one end of a steel pipe (801); A ball valve (804) is fixedly connected to the pipe body of the steel pipe (801) through a single - wire joint (803); The drill bit (901) to the drill pipe (902) part of the water stop device (9) is arranged inside the steel pipe (801) of the hole mouth pipe (8), and the drill bit (901) is arranged at the end of the grouting hole; A check valve (903) is arranged at one end of the drill pipe (902) connected to the drill bit (901); The other end of the drill pipe (902) is flange - connected to a pipe body (904), and the other end of the pipe body (904) is flange - connected to a three - way diverter (905); A high - temperature and high - pressure gate valve (906) is connected to the pipe body (904); An automatic control butterfly valve (907) is connected to the three - way diverter (905), and a slag discharge port (908) is arranged at the other end of the automatic control butterfly valve (907); 2. The dynamic sequential grouting method for ultra-high temperature hot water tunnel according to claim 1, characterized in that: The deepening blast holes (5) are arranged around the tunnel, with 10 holes, a length of 6 m, an outward inclination angle of 10 degrees, and a drilling diameter of 64 mm; 3. The ultra-high temperature hot water tunnel dynamic sequential grouting method according to claim 2, characterized in that: Specifically, step S4.1 is as follows: a) The heading face (3) is closed and leveled by hanging a double-layer Φ8 steel mesh and spraying 30 cm thick C30 concrete, and is connected to the steel mesh by heading face bolts (4). The bolts are 3 m long and arranged in a diamond pattern with a spacing of 1.5 m. b) The drilling rig platform (2) is 9 m long, and the height from the top surface to the top of the primary support arch is 6 m. The platform is cast with 10 cm thick C25 concrete.

4. A dynamic sequential grouting method for ultra-high temperature hot water tunnels according to claim 3, characterized in that: In the fourth step, the sequential dynamic grouting is carried out according to the constrained grouting. Combining the formation characteristics, the sectional progressive grouting is adopted to stop water, and the water inflow of the borehole is used as the sectional standard: ① When the water inflow of the borehole is not more than 5m 3 / h, grouting is carried out after the borehole reaches the final depth; ② When the water inflow of the borehole is 5 - 10m 3 / h, the sectional distance is 10 - 15m; ③ When the water inflow of the borehole is 10 - 30m 3 / h, the sectional distance is 5 - 10m; ④ When the water inflow of the borehole is more than 30m 3 / h, grouting is carried out immediately after stopping drilling; it is specifically determined according to the water inflow of the borehole on site.

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