A method for sealing dynamic water by double-liquid water-soluble polyurethane ground grouting

Abstract

The present invention discloses a method for sealing dynamic water flow using dual-liquid water-soluble polyurethane ground grouting. The method comprises the following steps: A) drilling a ground tunnel through the tunnel; B) installing a dual-tube grouting device; C) pressing water before grouting; D) preparing a dual-liquid water-soluble polyurethane grouting solution; E) mixing the dual-liquid water-soluble polyurethane grouting solution through the dual-tube grouting device and then grouting the solution to the target location; and F) pressing water after grouting. This method is a more efficient, environmentally friendly, and economical solution for controlling water inrush, effectively enhancing the effectiveness of sealing dynamic water flow in complex underground environments, thereby ensuring the safety of construction and operation of deep-buried tunnels.

Description

Technical Field

[0001] The present invention relates to the technical field of deep-buried tunnel water gushing control, in particular to a method for blocking moving water by ground grouting using two-liquid water-soluble polyurethane. Background Art

[0002] In the technical field of deep-buried tunnel water inrush control, water inrush is a common and challenging problem. During the construction or operation of a tunnel, water inrush often occurs due to the influence of various factors such as groundwater pressure, geological conditions, and construction methods. Water inrush not only affects the safety and progress of tunnel construction, but may also have an adverse impact on the surrounding environment. Traditional water inrush control methods include drainage, precipitation, and plugging. Drainage and precipitation methods require large equipment and energy inputs, and may have an impact on groundwater resources. The plugging method usually uses materials such as concrete and cement, but these materials have a long solidification time and are not effective in blocking dynamic water. Patent CN113683369A adds polyacrylamide and the like to water to form a modified cement slurry as liquid A and polyurethane as liquid B. It utilizes the characteristic of water-based polyurethane to react with water to form a gel, and then mixes liquid A and liquid B and injects them into the target stratum to achieve dynamic water blocking. However, when this method is used for water inrush control in deep-buried tunnels, especially when the dynamic water flow rate is high, the mechanical strength and stability of the solidified body formed are difficult to achieve an ideal blocking effect. Summary of the Invention

[0003] To this end, the technical problem to be solved by the present invention is to provide a method for sealing dynamic water by two-liquid water-soluble polyurethane ground grouting, which is easy to operate, safe in process and reliable in effect, so as to solve the problem that the existing sealing materials and sealing methods have poor sealing effect when dealing with the dynamic water problem of deep buried tunnels, especially when the dynamic water flow rate is large, and the mechanical strength and stability of the formed solid body are poor.

[0004] The two-liquid water-soluble polyurethane grouting method proposed in the present invention has the advantages of short setting time, high strength, and good anti-seepage performance. It can quickly and effectively block dynamic water and is a relatively advanced method for water inrush control. The two-liquid water-soluble polyurethane ground grouting method for blocking dynamic water proposed in the present invention is a more efficient, environmentally friendly, and economical water inrush control solution. It can effectively enhance the management effect of dynamic water blocking in complex underground environments, thereby ensuring the construction and operation safety of deep buried tunnels.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A method for sealing moving water by two-liquid water-soluble polyurethane ground grouting comprises the following steps:

[0007] Step A: Ground tunnel drilling construction;

[0008] Step B, installing a double-tube grouting device;

[0009] Step C, pressurizing water before grouting;

[0010] Step D, preparing a two-liquid water-soluble polyurethane grouting liquid;

[0011] Step E: mixing the two-liquid water-soluble polyurethane grouting liquid through a double-tube grouting device and then grouting it to the target position;

[0012] Step F: Pressurize water after grouting.

[0013] The above-mentioned two-liquid water-soluble polyurethane ground grouting method for blocking moving water, in step D, the two-liquid water-soluble polyurethane grouting liquid is composed of liquid A and liquid B; liquid A is composed of 84-94 parts by weight of sodium silicate solution, 5-15 parts by weight of polyether polyol composite catalyst (polyether polyol composite catalyst refers to a catalyst that can be used to catalyze the foaming reaction of polyether polyol and polymethylene polyphenyl polyisocyanate, and can be a commercially available polyether polyol composite catalyst) and 0.1-1 parts by weight of an organosilicon foam stabilizer; the concentration of the sodium silicate solution is 40 degrees Baume (i.e., the solid content of sodium silicate is 35wt%);

[0014] Liquid B is a polymethylene polyphenyl polyisocyanate solution with a concentration of 20wt% to 35wt%, wherein the isocyanate content of the polymethylene polyphenyl polyisocyanate is greater than or equal to 30%; the solvent of the polymethylene polyphenyl polyisocyanate solution is chlorobenzene, o-dichlorobenzene or toluene.

[0015] In the above-mentioned method for sealing dynamic water by double-liquid water-soluble polyurethane ground grouting, in step B, the double-tube grouting device includes a first grouting pump, a second grouting pump, a first grouting pipe, a second grouting pipe, a casing, a bottom hole mixer and a fishtail drill bit; the fluid outlet end of the first grouting pump is fluidly connected to the fluid inlet end of the first grouting pipe, and the fluid outlet end of the second grouting pump is fluidly connected to the fluid inlet end of the second grouting pipe; the fluid outlet end of the first grouting pipe and the fluid outlet end of the second grouting pipe are both fluidly connected to the fluid inlet end of the bottom hole mixer; the fluid outlet end of the bottom hole mixer is fluidly connected to the fluid inlet end of the fishtail drill bit; the fluid inlet end of the first grouting pump is fluidly connected to the A liquid stirring barrel, and the fluid inlet end of the second grouting pump is fluidly connected to the B liquid stirring barrel;

[0016] The inner diameter of the first grouting pipe is larger than the outer diameter of the second grouting pipe; the fluid outlet end of the second grouting pipe extends from the fluid inlet end of the first grouting pipe to the fluid outlet end of the first grouting pipe, and the central axes of the first grouting pipe and the second grouting pipe coincide with each other; the inner diameter of the casing is larger than the outer diameter of the first grouting pipe; the fluid outlet end of the first grouting pipe extends from the ground end of the casing to the underground end of the casing, and the central axes of the first grouting pipe and the casing coincide with each other; the first grouting pipe is fixed to the casing by a flange; the casing is fixed in the grouting borehole by solid pipe cement slurry.

[0017] In the above-mentioned two-liquid water-soluble polyurethane ground grouting method for blocking moving water, the inner diameter of the first grouting pipe is 1.7 to 2.2 times the inner diameter of the second grouting pipe. When the inner diameters of the first and second grouting pipes are within this ratio, the delivered liquids A and B can be mixed more evenly in the bottom-hole mixer, and the two grouting liquids react more quickly and fully, thereby producing a consolidated body with better performance.

[0018] In the above-mentioned method of double-liquid water-soluble polyurethane ground grouting to block moving water, the first grouting pipe is a Φ89 drill tool, and the second grouting pipe is a Φ42 drill tool; since the amount of liquid A used is relatively large relative to the amount of liquid B, the present invention has found in repeated experiments that when the Φ89 drill tool and the Φ42 drill tool are used as grouting pipes for liquid A and liquid B respectively, the reaction of liquid A and liquid B after mixing is most sufficient, and basically no waste of materials will be caused; the outer diameter of the casing is 244.5mm, and the wall thickness is 8.94mm; the first grouting pump is an F260 grouting pump, and the second grouting pump is an NBB390 grouting pump. Before the installation of the one-way valve of the second grouting pipe, the one-way valve spring needs to be cut off one and a half turns to reduce the problem of excessive pipe resistance caused by the one-way valve. The pipe resistance of the double pipe (i.e., the first grouting pipe and the second grouting pipe) is controlled at a pump pressure of about 0.3MPa); the pump volume of the F260 grouting pump can be adjusted in the range of 0 to 40m 3 The maximum pump pressure can reach 15MPa, and the pump volume of NBB-390 grouting pump can be adjusted in five gears (1st gear 3.1m 3 / h, 2nd gear 5.4m 3 / h, 3rd gear 9.6m 3 / h, 4th gear 15m 3 / h, 5th gear 23.4m 3 / h), the maximum pump pressure can reach 8MPa.

[0019] In the above-mentioned two-liquid water-soluble polyurethane ground grouting method for blocking moving water, in step E, during grouting, the flow rates of liquid A and liquid B are controlled so that they are mixed in a bottom-hole mixer at a mass ratio of 1:(0.5-1.0). When liquid A and liquid B are mixed within the above-mentioned ratio range, they can react sufficiently and rapidly to form a solidified body with a stable structure and relatively ideal mechanical strength, resulting in high solidification efficiency, good grouting and water blocking effects, and the use of materials is extremely economical, without causing material waste.

[0020] In the above-mentioned method of two-liquid water-soluble polyurethane ground grouting to block moving water, in step E, during grouting, the flow rates of liquid A and liquid B are controlled so that they are mixed in the bottom hole mixer at a mass ratio of 1:1.

[0021] In the above-mentioned dual-liquid water-soluble polyurethane ground grouting method for blocking dynamic water flow, in step E, the flow rates of both Liquid A and Liquid B during grouting are 90 to 190 L / min. When the flow rates of Liquid A and Liquid B are within this range, the two liquids react fully, and the diffusion range formed when delivered to the bottom of the hole through the above-mentioned dual-tube grouting device meets the requirements for blocking dynamic water flow in deep tunnels, achieving a good dynamic water blocking effect.

[0022] In the above-mentioned two-component water-soluble polyurethane ground grouting method for blocking moving water, in step E, during grouting, the temperature of the two-component water-soluble polyurethane grouting liquid is controlled at 20-25°C; or, during grouting, the viscosity of the two-component water-soluble polyurethane grouting liquid is controlled at 60-80s. The grouting raw materials (two-component water-soluble polyurethane grouting liquid) are transported to an insulation room for preheating two days in advance. After the grouting drill is lowered into place and the double-tube grouting device is installed, and the water pressure test is normal, they are transported to the on-site grouting station.

[0023] In the above-mentioned method of ground grouting to block moving water by two-liquid water-soluble polyurethane, in step A, the ground construction is precisely drilled to 0.8 to 1.5 m below the bottom plate of the water-gushing tunnel, and the drilling deviation rate is less than or equal to 1‰. The purpose of ground construction through-tunnel drilling is to inject two-liquid water-soluble polyurethane into the moving water area to achieve the purpose of blocking. During the drilling process, it is necessary to select the appropriate drilling position, diameter and depth according to the actual situation (including the properties of the two-liquid water-soluble polyurethane, etc.), and use professional drilling equipment for operation. After the drilling is completed, the borehole should be cleaned and inspected to ensure that the drilling quality meets the requirements and provide protection for the subsequent grouting and blocking work;

[0024] In step B, before double-tube drilling, the mixer is checked and cleaned, and the one-way valve is installed; the bottom of the drill tool is connected to the bottom hole mixer, the lower part of the mixer is connected to the fishtail drill bit, and the bottom of the drill bit extends into the deep buried tunnel; after the double-tube drilling rig and the bottom hole mixer are lowered, the orifice grouting device is installed, the inner and outer pipe seals must be installed securely, and the sealing ring must be fully greased and squeezed tightly; during the grouting process, the drill tool is moved up and down based on the remaining water flow space, and the range of movement is 0.4 to 1.5 m (it can also be determined according to the bottom conditions of each borehole). If the range of movement of the drill tool is too large, it will affect the stability of the accumulation body generated at the bottom, thereby affecting the rapid accumulation of slurry; the grouting liquid is mixed at the bottom of the hole, and the slurry is not only drilled, but also flows into the tunnel through the fishtail drill bit; compared with other types of drill bits, the fishtail drill bit used in the present invention can make the grouting liquid better form a stable consolidation body at the target position;

[0025] In step C, a water pressure test is performed before grouting using clean water at a temperature of 20 to 25°C. During the water pressure test, the double tubes are first subjected to a water pressure test separately and then to a water pressure test on the double tubes simultaneously. The standard for the water pressure test is that the double tubes are not connected in series at the top of the bottom hole mixer and the water pressure of the single pipeline meets the pump pressure of 0.25 to 0.35 MPa (preferably 0.3 MPa).

[0026] In step D, personnel are arranged to carry liquid A and liquid B of the two-liquid water-soluble polyurethane grouting fluid that meet the temperature requirements and place them in two grouting mixing barrels (liquid A mixing barrel and liquid B mixing barrel) of the grouting station respectively. When the grouting pump is continuously grouting, materials are continuously taken and added, and the temperature of the two-liquid water-soluble polyurethane grouting fluid is maintained to facilitate the continuous grouting operation of the grouting pump. The technicians detect the temperature of the AB two-liquid water-soluble polyurethane grouting fluid in the mixing barrel at any time; during outdoor construction in winter, the grouting mixing barrel is wrapped with a heating tape for continuous heating and is covered with rubber and plastic insulation cotton. Before grouting is implemented, the temperature of the grouting mixing barrel is not lower than the temperature of the AB two-liquid water-soluble polyurethane grouting fluid; the grouting pipeline from the grouting pump to the drilling site is wrapped with a constant temperature heating tape and rubber and plastic insulation cotton, and is maintained at a constant temperature to ensure that the slurry does not increase in viscosity due to continuous cooling of the grouting pipeline during grouting;

[0027] Before grouting, technicians measure the temperature of the AB double-liquid water-soluble polyurethane grouting liquid after heating in real time. The heating temperature must be controlled above 20°C (preferably 20-25°C). After the technicians confirm that the heating of the A and B double-liquid water-soluble polyurethane grouting liquids meets the grouting requirements and the viscosity is reduced, they will notify the grouting personnel to proceed with the grouting construction;

[0028] In step E, during the dual-liquid grouting process, the pump pressure of the outer tube (first grouting tube) is about 0.3Mpa at 180L / min, and the pump pressure of the inner tube (second grouting tube) is about 0.2Mpa at 90L / min; during the grouting period, the grouting team leader monitors the dual-pump grouting pressure in real time. When the single-pump grouting pressure rises to 50% of the rated grouting pressure of the grouting pump, the grouting is immediately stopped and the single pump is staggered for 30s to pressurize the water (to flush the pipeline and clean the two materials remaining in the pipeline to avoid clogging the pipe and the hole). When the water pressure drops to the normal grouting pressure, the normal grouting work is resumed, and the process is repeated in sequence;

[0029] In step F, after grouting is completed, the two pumps are staggered for 30 seconds to perform post-injection water pressure. After water pressure, the double-tube drilling tool grouting pipeline at the orifice is disconnected, and the two-way drilling tools are simultaneously lifted up about 50 meters. Then, the drilling tools are lifted in the order of first lifting the inner tube and then the outer tube.

[0030] If a power outage occurs during grouting, stop grouting immediately. Place the outer grouting pump suction pipe in the clean water tank immediately, and continue to place the inner grouting pump suction pipe in the grouting liquid. Start the outer grouting pump immediately, and start the inner grouting pump after a delay of 10 seconds. Immediately pressurize the outer pipe and continue to pour grouting liquid into the inner pipe. Wait for 30 seconds for the outer pipe grouting pump to pressurize the water. After the inner and outer pipe grouting pumps have completed water pressurization, the grouting station immediately shuts down the grouting pump and starts the air pump to clean the grouting pipeline. At the same time, the drilling rig starts to pull out the dual-path grouting drill tool.

[0031] The technical solution of the present invention achieves the following beneficial technical effects:

[0032] 1. When Liquid A and Liquid B of the two-component water-soluble polyurethane grouting fluid are heated to 20-25°C, their viscosity is reduced to meet the requirements of self-priming grouting by an on-site grouting pump, and the foaming time after mixing the two liquids is accelerated. The two-component water-soluble polyurethane material of the present invention has excellent chemical stability, mechanical strength, and water resistance. It can quickly solidify in a dynamic water environment with a high dynamic water flow rate to form a watertight solid body, achieving the purpose of blocking dynamic water flow. While ensuring the treatment effect of deep buried tunnels, it also reduces the construction cost of the plugging.

[0033] 2. The two-liquid water-soluble polyurethane grouting material of the present invention has low viscosity after mixing with water and good groutability. Its solid body is non-toxic, non-polluting and harmless to the human body when immersed in water. It also has excellent corrosion resistance and water erosion resistance, and can maintain the waterproof and anti-seepage capabilities of the structure for a long time.

[0034] 3. The present invention's dual-liquid water-soluble polyurethane grouting method for ground grouting and blocking dynamic water, through innovative materials and processes, provides a new solution for treating water inrush in deep tunnels. This method not only broadens the range of treatment materials available but also optimizes the construction process, significantly improving treatment efficiency and success rate. The method is economical and practical, with an efficient construction process, simple operation steps, and low economic cost.

[0035] 4. The dual-liquid grouting device of the present invention inserts the second grouting pipe used for grouting the B liquid in the present invention into the first grouting pipe used for grouting the A liquid in the present invention, and installs a bottom hole mixer at the bottom of the double pipe. By selecting a drill bit with a specific inner diameter as the first grouting pipe and the second grouting pipe, the A liquid and the B liquid in the present invention can be quickly and fully mixed in the bottom hole mixer, which is conducive to a rapid reaction to generate a solid body with ideal mechanical strength. At the same time, by controlling the grouting flow rate of the A liquid and the B liquid, the grouting liquid has a suitable diffusion range, which can quickly form a solid body with good stability at the dynamic water position of the deep-buried tunnel where the dynamic water flow rate is large. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of a method for ground grouting and plugging dynamic water using a two-liquid water-soluble polyurethane grouting liquid according to an embodiment of the present invention;

[0037] Figure 2 Operation flow chart of the method for ground grouting and plugging dynamic water using a double-liquid water-soluble polyurethane grouting liquid according to an embodiment of the present invention;

[0038] Figure 3 A schematic diagram of a method for ground grouting and blocking dynamic water using a two-liquid water-soluble polyurethane grouting liquid in another embodiment of the present invention.

[0039] The reference numerals are as follows: 1-first grouting pump; 2-second grouting pump; 3-first grouting pipe; 4-second grouting pipe; 5-fastening bolts; 6-upper and lower flanges; 7-A liquid mixing barrel; 8-B liquid mixing barrel; 9-solid pipe cement slurry; 10-casing; 11-bottom hole mixer; 12-fishtail drill bit; 13-consolidation body; 14-water gushing direction. DETAILED DESCRIPTION

[0040] The method of double-liquid water-soluble polyurethane ground grouting to block dynamic water was tested in an engineering test. The operation process is shown in FIG. Figure 2 , specifically including the following steps:

[0041] Step A: Ground tunnel drilling: Ground tunnel drilling is performed to inject two-liquid water-soluble polyurethane into the moving water area to achieve the purpose of plugging. During the drilling process, it is necessary to select the appropriate drilling location, diameter, and depth based on the actual situation, and use professional drilling equipment for the operation. After drilling is completed, the borehole should be cleaned and inspected to ensure that the drilling quality meets the requirements and provide support for subsequent grouting and plugging work. The ground construction is accurately drilled to 1m below the bottom plate of the water-gushing tunnel, and the drilling deviation rate is less than or equal to 1‰.

[0042] Step B: Install the double-tube grouting device, lower the double-tube drilling tool and the bottom hole mixer;

[0043] The double-tube grouting device in this embodiment is as follows Figure 1 As shown, it includes a first grouting pump 1, a second grouting pump 2, a first grouting pipe 3, a second grouting pipe 4, a casing 10, a bottom hole mixer 11 and a fishtail drill bit 12; the fluid outlet end of the first grouting pump 1 is fluidly connected to the fluid inlet end of the first grouting pipe 3, and the fluid outlet end of the second grouting pump 2 is fluidly connected to the fluid inlet end of the second grouting pipe 4; the fluid outlet end of the first grouting pipe 3 and the fluid outlet end of the second grouting pipe 4 are both fluidly connected to the fluid inlet end of the bottom hole mixer 11; the fluid outlet end of the bottom hole mixer 11 is fluidly connected to the fluid inlet end of the fishtail drill bit 12; the fluid inlet end of the first grouting pump 1 is fluidly connected to the A liquid stirring barrel 7, and the fluid inlet end of the second grouting pump 2 is fluidly connected to the B liquid stirring barrel 8;

[0044] The inner diameter of the first grouting pipe 3 is larger than the outer diameter of the second grouting pipe 4; the fluid outlet end of the second grouting pipe 4 extends from the fluid inlet end of the first grouting pipe 3 to the fluid outlet end of the first grouting pipe 3, and the central axes of the first grouting pipe 3 and the second grouting pipe 4 coincide with each other; the inner diameter of the casing 10 is larger than the outer diameter of the first grouting pipe 3; the fluid outlet end of the first grouting pipe 3 extends from the ground end of the casing 10 to the underground end of the casing 10, and the central axes of the first grouting pipe 3 and the casing 10 coincide with each other; the first grouting pipe 3 is fixed to the casing 10 by a flange 6; the casing 10 is fixed in the grouting borehole by solid pipe cement slurry 9.

[0045] The first grouting pipe 3 is a Φ89 drill bit, and the second grouting pipe 4 is a Φ42 drill bit; the outer diameter of the casing 10 is 244.5 mm and the wall thickness is 8.94 mm; the first grouting pump 1 is an F260 grouting pump, and the second grouting pump 2 is an NBB390 grouting pump; the one-way valve spring of the second grouting pipe needs to be cut off one and a half turns before the one-way valve is installed to reduce the problem of excessive pipe resistance caused by the one-way valve. The pipe resistance of the double pipe (i.e., the first grouting pipe and the second grouting pipe) is controlled at a pump pressure of about 0.3 MPa); the pump volume of the F260 grouting pump can be adjusted from 0 to 40 m3 The maximum pump pressure can reach 15MPa, and the pump volume of NBB-390 grouting pump can be adjusted in five gears (1st gear 3.1m 3 / h, 2nd gear 5.4m 3 / h, 3rd gear 9.6m 3 / h, 4th gear 15m 3 / h, 5th gear 23.4m 3 / h), the maximum pump pressure can reach 8MPa;

[0046] Before lowering the double-tube drill, inspect and clean the mixer and install the one-way valve. Connect the bottom of the drill string to the bottom-hole mixer, which is then connected to the fishtail drill bit. The bottom of the drill bit extends into the deep-buried tunnel. The Φ89 drill string is used for grouting with Liquid A, and the Φ42 drill string is used for grouting with Liquid B. After the double-tube drill string and the bottom-hole mixer are lowered, install the orifice grouting device. Ensure that the inner and outer tube seals are securely installed, and the sealing rings are fully greased and squeezed tightly.

[0047] During the grouting process, the drill tool is moved up and down based on the remaining water flow space, with a range of 0.4 to 1.5 meters (which can also be determined according to the bottom conditions of each borehole). The grouting liquid is mixed at the bottom of the hole. As the hole is drilled, the grouting liquid flows into the tunnel through the fishtail drill bit. Before drilling the double pipes (the first grouting pipe and the second grouting pipe), the mixer is inspected and cleaned, and the one-way valve is installed. During the double-liquid grouting process, the pump pressure of the outer pipe is about 0.3 MPa at 180 L / min, and the pump pressure of the inner pipe is about 0.2 MPa at 90 L / min.

[0048] Step C, water pressure before grouting; before grouting, water pressure test is carried out using clean water with a temperature of 20-25°C. During the water pressure test, the double tubes are first subjected to water pressure test separately and then to water pressure test on the double tubes simultaneously; the standard of the water pressure test is: the double tubes are not connected in series on the upper part of the bottom hole mixer and the water pressure of the single pipeline meets the pump pressure of 0.3MPa.

[0049] Step D, preparing a two-liquid water-soluble polyurethane grouting liquid; the two-liquid water-soluble polyurethane grouting liquid consists of liquid A and liquid B; liquid A consists of 45 kg of sodium silicate solution, 4.75 kg of polyether polyol composite catalyst and 0.25 kg of organosilicon foam stabilizer; the concentration of the sodium silicate solution is 40 degrees Baume, that is, the content of sodium silicate is 35wt%; liquid B is 50 kg of a 35% concentration of polymethylene polyphenyl polyisocyanate solution, the solvent is toluene, and the isocyanate content of the polymethylene polyphenyl polyisocyanate is 40%.

[0050] Liquid A and liquid B of the two-liquid water-soluble polyurethane grouting fluid that meet the temperature requirements are placed in two grouting stirring barrels (liquid A stirring barrel and liquid B stirring barrel) of the grouting station respectively. When the grouting pump is continuously grouting, the material is continuously taken and added, and the temperature of the two-liquid water-soluble polyurethane grouting fluid is maintained, so as to facilitate the continuous grouting operation of the grouting pump. The technicians detect the temperature of the AB two-liquid water-soluble polyurethane grouting fluid in the stirring barrel at any time. Since the present embodiment is constructed outdoors in winter, the grouting stirring barrel is wrapped with a heating tape for continuous heating and is covered with rubber and plastic thermal insulation cotton. Before grouting is implemented, the temperature of the grouting stirring barrel is higher than or equal to the temperature of the two-liquid water-soluble polyurethane grouting fluid. The grouting pipeline from the grouting pump to the drilling site is wrapped with a constant temperature heating tape and rubber and plastic thermal insulation cotton and is maintained at a constant temperature.

[0051] The grouting raw materials (two-liquid water-soluble polyurethane grouting liquid) are transported to the insulation room for preheating two days in advance. After the grouting drill is lowered into place and the double-tube grouting device is installed and the water pressure test is normal, they are transported to the on-site grouting station. Before grouting, the technicians measure the temperature of the AB two-liquid water-soluble polyurethane grouting liquid after heating in real time. The heating temperature must be controlled above 20°C (preferably 20-25°C). After the technicians confirm that the heating of the A and B two-liquid water-soluble polyurethane grouting liquids meets the grouting requirements and the viscosity is reduced, they notify the grouting personnel to proceed with the grouting construction;

[0052] Step E: Mix the two-liquid water-soluble polyurethane grouting liquid through a double-tube grouting device and inject it into the target location. During grouting, control the flow rate of liquid A and liquid B so that they are mixed in a bottom-hole mixer at a mass ratio of 1:1. During grouting, control the temperature of the two-liquid water-soluble polyurethane grouting liquid to 20-25°C.

[0053] In this embodiment, the flow rates of liquid A and liquid B are both 160 L / min. During grouting, the grouting pressure of the dual pumps is monitored in real time. When the grouting pressure of a single pump rises to 50% of the rated grouting pressure of the grouting pump, the grouting is immediately stopped and the single pump is staggered for 30 seconds to pressurize the water. When the pressurized water drops to the normal grouting pressure, the normal grouting work is resumed, and this process is repeated in sequence.

[0054] Step F: Post-grouting water pressure. After grouting, stagger the two pumps for 30 seconds to perform post-grouting water pressure. After water pressure, disconnect the double-tube drilling tool grouting pipeline at the orifice. Lift the two-tube drilling tools simultaneously by about 50 meters. Then, lift the inner tube first and then the outer tube in the order of lifting the drilling tools.

[0055] If a power outage occurs during grouting, stop grouting immediately. Place the outer grouting pump suction pipe in the clean water tank immediately, and continue to place the inner grouting pump suction pipe in the grouting liquid. Start the outer grouting pump immediately, and start the inner grouting pump after a delay of 10 seconds. Immediately pressurize the outer pipe and continue to pour grouting liquid into the inner pipe. Wait for 30 seconds for the outer pipe grouting pump to pressurize the water. After the inner and outer pipe grouting pumps have completed water pressurization, the grouting station immediately shuts down the grouting pump and starts the air pump to clean the grouting pipeline. At the same time, the drilling rig starts to pull out the dual-path grouting drill tool.

[0056] The dynamic water flow rate of the deep buried tunnel in this embodiment is 1000m 3 / h. The above construction method can achieve rapid blocking of dynamic water within 72 hours, and the formed stone consolidation body has good mechanical strength (24h compressive strength 38MPa, greater than 30MPa, shear strength 13MPa, greater than 10MPa, tensile strength 7MPa, greater than 5MPa), and the blocking effect is sustained and stable.

[0057] In other embodiments, the following may also be used: Figure 3 The double-tube grouting device shown in the embodiment is used to perform the double-liquid water-soluble polyurethane ground grouting to block the dynamic water in the above embodiment, but its blocking effect is relatively poor compared with the above embodiment (dynamic water flow rate 900m 3 / h, plugging was achieved in 82H, and the formed solid body had a compressive strength of 25MPa, shear strength of 8MPa, and tensile strength of 4.5MPa in 24h. This may be because when the first grouting pipe and the second grouting pipe were filled according to Figure 3 When installed in this manner, the mixing efficiency and mixing effect of liquid A and liquid B are not as good as the case where the second grouting pipe is set inside the first grouting pipe in the above embodiment, thereby affecting the reaction rate and reaction sufficiency of liquid A and liquid B.

[0058] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the claims of this patent application.

Claims

1. A method for sealing dynamic water by two-liquid water-soluble polyurethane ground grouting, characterized in that: The steps include: Step A: Surface tunnel drilling: Drill accurately to a point 0.8 to 1.5 meters below the bottom plate of the water-gushing tunnel, with a drilling deviation rate of less than or equal to 1‰; Step B: Install the double-tube grouting device; during the grouting process, the drill bit is moved up and down based on the remaining water flow space, with a range of 0.4 to 1.5 meters, and the grouting does not stop at the drilling hole; The double-tube grouting device comprises a first grouting pump (1), a second grouting pump (2), a first grouting pipe (3), a second grouting pipe (4), a casing (10), a bottom hole mixer (11) and a fishtail drill bit (12); the fluid outlet end of the first grouting pump (1) is in fluid communication with the fluid inlet end of the first grouting pipe (3), and the fluid outlet end of the second grouting pump (2) is in fluid communication with the fluid inlet end of the second grouting pipe (4); the fluid outlet end of the first grouting pipe (3) and the fluid outlet end of the second grouting pipe (4) are both in fluid communication with the fluid inlet end of the bottom hole mixer (11); the fluid outlet end of the bottom hole mixer (11) is in fluid communication with the fluid inlet end of the fishtail drill bit (12); the fluid inlet end of the first grouting pump (1) is in fluid communication with the A liquid stirring barrel (7), and the fluid inlet end of the second grouting pump (2) is in fluid communication with the B liquid stirring barrel (8); Step C, water pressure before grouting; before grouting, water pressure is tested using clean water at a temperature of 20 to 25°C. During the water pressure test, the first grouting pipe (3) and the second grouting pipe (4) are respectively subjected to water pressure tests, and then the first grouting pipe (3) and the second grouting pipe (4) are simultaneously subjected to water pressure tests; the standard of the water pressure test is that the first grouting pipe (3) and the second grouting pipe (4) are not connected in series at the top of the bottom hole mixer (11) and the water pressure of the single-channel pipeline meets the pump pressure of 0.25 to 0.35 MPa; Step D, preparing a two-liquid water-soluble polyurethane grouting liquid; during outdoor construction in winter, the grouting mixing barrel is wrapped with a heating tape for continuous heating, and is covered with rubber and plastic thermal insulation cotton. Before grouting, the temperature of the grouting mixing barrel is higher than or equal to the temperature of the two-liquid water-soluble polyurethane grouting liquid; the grouting pipeline from the grouting pump to the drilling site is wrapped with a constant temperature heating tape and rubber and plastic thermal insulation cotton, and is maintained at a constant temperature by heating; Step E, mixing the dual-liquid water-soluble polyurethane grouting liquid through a dual-tube grouting device and then grouting it to the target position; during the dual-liquid grouting process, when the flow rate of the first grouting pipe (3) is 180L / min, the pump pressure is 0.3Mpa, and when the flow rate of the second grouting pipe (4) is 90L / min, the pump pressure is 0.2Mpa; during the grouting process, the dual-pump grouting pressure is monitored in real time, and when the single-pump grouting pressure rises to 50% of the rated grouting pressure of the grouting pump, the grouting is immediately stopped and the single pump is staggered for 30s to pressurize the water, and when the water pressure drops to the normal grouting pressure, the normal grouting work is resumed, and the process is repeated in sequence; Step F: Post-grouting water pressure: After grouting, the two pumps are staggered for 30 seconds to perform post-grouting water pressure. After water pressure, the double-tube drilling tool grouting pipelines at the orifice are disconnected, and the two-way drilling tools are simultaneously lifted up about 50m. Then, the drilling tools are lifted in the order of first lifting the inner tube and then the outer tube; When a sudden power outage occurs during grouting, grouting is stopped immediately. The suction pipe of the first grouting pump (1) is immediately placed in the clean water tank, and the suction pipe of the second grouting pump (2) continues to be placed in the grouting liquid B. The first grouting pump (1) is immediately started, and the second grouting pump (2) is started after a delay of 10 seconds. The first grouting pipe (3) is immediately pressurized with water, and the second grouting pipe (4) immediately continues to be filled with grouting liquid B. When the first grouting pump (1) pressurizes water for 30 seconds, the second grouting pump (2) pressurizes water. After the first grouting pump (1) and the second grouting pump (2) have completed pressurizing water, the grouting station immediately shuts down the two grouting pumps and starts the air pump to clean the grouting pipeline. At the same time, the drilling rig is started to pull out the first grouting pipe (3) and the second grouting pipe (4).

2. The method for sealing dynamic water by two-liquid water-soluble polyurethane ground grouting according to claim 1, characterized in that: In step D, the two-liquid water-soluble polyurethane grouting liquid is composed of liquid A and liquid B; liquid A is composed of 84 to 94 parts by weight of a sodium silicate solution, 5 to 15 parts by weight of a polyether polyol composite catalyst, and 0.1 to 1 part by weight of an organosilicon foam stabilizer; the concentration of the sodium silicate solution is 40 degrees Baume; Liquid B is a polymethylene polyphenyl polyisocyanate solution with a concentration of 20 wt % to 35 wt %, and the isocyanate content of the polymethylene polyphenyl polyisocyanate is greater than or equal to 30%.

3. The method for sealing dynamic water by two-liquid water-soluble polyurethane ground grouting according to claim 2, characterized in that: In step B, the inner diameter of the first grouting pipe (3) is larger than the outer diameter of the second grouting pipe (4); the fluid outlet end of the second grouting pipe (4) extends from the fluid inlet end of the first grouting pipe (3) to the fluid outlet end of the first grouting pipe (3), and the central axes of the first grouting pipe (3) and the second grouting pipe (4) coincide with each other; the inner diameter of the casing (10) is larger than the outer diameter of the first grouting pipe (3); the fluid outlet end of the first grouting pipe (3) extends from the ground end of the casing (10) to the underground end of the casing (10), and the central axes of the first grouting pipe (3) and the casing (10) coincide with each other; the first grouting pipe (3) is fixed to the casing (10) by a flange (6); and the casing (10) is fixed in the grouting borehole by a pipe-fixing cement slurry (9).

4. The method for sealing dynamic water by two-liquid water-soluble polyurethane ground grouting according to claim 3, characterized in that: The inner diameter of the first grouting pipe (3) is 1.7 to 2.2 times the inner diameter of the second grouting pipe (4).

5. The method for sealing dynamic water by two-liquid water-soluble polyurethane ground grouting according to claim 4, characterized in that: The first grouting pipe (3) is a Φ89 drilling tool, and the second grouting pipe (4) is a Φ42 drilling tool; the outer diameter of the casing (10) is 244.5 mm, and the wall thickness is 8.94 mm; the first grouting pump (1) is an F260 grouting pump, and the second grouting pump (2) is an NBB390 grouting pump.

6. The method for sealing dynamic water by two-liquid water-soluble polyurethane ground grouting according to claim 2, characterized in that: In step E, during grouting, the flow rates of liquid A and liquid B are controlled so that the mass ratio of the two is 1:(0.5-1.0).

7. The method for sealing dynamic water by two-liquid water-soluble polyurethane ground grouting according to claim 6, characterized in that: In step E, during grouting, the flow rates of liquid A and liquid B are controlled so that the mass ratio of the two is 1:

1.

8. The method for sealing dynamic water by two-liquid water-soluble polyurethane ground grouting according to claim 7, characterized in that: In step E, during grouting, the flow rates of liquid A and liquid B are both 90 to 190 L / min.

9. The method for sealing dynamic water by two-liquid water-soluble polyurethane ground grouting according to claim 2, characterized in that: In step E, during grouting, the temperature of the two-liquid water-soluble polyurethane grouting liquid is controlled to be 20-25° C.; or during grouting, the viscosity of the two-liquid water-soluble polyurethane grouting liquid is controlled to be 60-80s.

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