A method for controlling relatively concentrated water inrush in underground projects

Abstract

The present invention discloses a method for treating relatively concentrated water gushing in underground projects. The specific steps are: draining the underground project to expose the water outlet; cleaning the base of the underground project; trimming the water outlet and detecting the extension direction of the water outlet channel; using pipes to collect and guide water; extending the water guide pipes; flooding the underground space; raising the tail end of the water guide pipe to the water surface; using the water guide pipes to grout and pump out the accumulated water in the underground space. The core of the present invention is to use the water guide pipes to guide and collect water at the water outlet point, and then use the water from the underground project itself to flood the underground space. In this way, when using the water guide pipes for grouting treatment, the water accumulated in the underground space itself can be relied on to form a certain offset to the grouting pressure, relatively reducing the effect of the grouting pressure on the rock layer near the water outlet point. While ensuring the effective diffusion of the slurry, it can also prevent the damage to the base rock layer, so as to ensure the safety and effect of the treatment.

Description

Technical Field

[0001] The present invention relates to the field of groundwater treatment methods, and in particular to a method for treating relatively concentrated water gushing in underground projects. Background Art

[0002] When excavating deep foundation pits, tunnels, lanes, shafts, and basements, if water-rich rock layers are encountered, water inrush accidents may occur if detection and treatment are not timely, which may cause direct flooding of underground spaces or cause a large amount of energy waste and economic losses if long-term strong drainage is used. For example, in a deep foundation pit under construction on Line 4 of the Xuzhou Metro in Jiangsu Province, the water output from the limestone base reaches 1500m 3 / h, with a daily drainage of 36,000m 3 The daily drainage cost reached 36,000 yuan.

[0003] At present, there are generally the following ways to deal with large amounts of water gushing caused by the accidental exposure of water-bearing bodies in underground projects. One is to bury grouting pipes directly in the outlet and the channel. After the grouting pipes are solidified, grouting and sealing are performed directly through the grouting pipes. This method is suitable for water discharge from rock formations with low water pressure, regular water outlets, and high rock strength and stability. For working conditions with relatively low rock strength, once the grouting pipes are closed before grouting, as the water pressure at the water outlet rises, the grouting pipes may be directly loosened or even pulled out, and the rock formation may be damaged, resulting in new water outlets. The second is a method for sealing high-pressure and high-flow water inrush in mines, such as the Chinese patent application number 2019108697755. The method disclosed in the law is to first construct a drainage drill hole on the water outlet channel, and then grout the water outlet after the water is drained. This method requires a clear understanding of the grouting channel to implement; thirdly, if the Chinese patent application number is 2010106164844, the static water cement grouting pad construction method; the Chinese patent application number is 2015104209843, the inclined well underwater grouting pad construction method disclosed, if the underground project is flooded, a certain thickness of concrete water stop pad is poured underwater, and after the grouting pad is fully cured, the accumulated water is pumped out, and then grouting water stopping operations are performed on the grouting pad. This method is mainly suitable for underground projects with small bases. The cast grouting pad often needs to be thicker. After the grouting pad achieves the effect, the water outlet needs to be sealed in the later stage. Summary of the Invention

[0004] In response to the above-mentioned technical deficiencies, the purpose of the present invention is to provide a method for controlling relatively concentrated water gushing in underground projects, which fully considers the characteristics of the water outlet points, geological and hydrogeological conditions, and is mainly suitable for the control of water gushing points in underground projects with relatively concentrated water outlets, weak rock strata strength, large underground project bases, and relatively shallow burials. It has the characteristics of simple principle, safety, reliability, and easy operation.

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

[0006] The present invention provides a method for treating relatively concentrated water inrush in underground engineering, comprising the following steps:

[0007] S1. Drainage of underground projects to expose water outlets: Use the drainage system to continuously pump out the accumulated and gushing water in underground projects to fully expose the water outlets at the base;

[0008] S2. Cleaning the underground engineering base: During the continuous pumping of accumulated and gushing water to the base, personnel and machinery enter the underground engineering base to clean the water outlet points, clearing away surrounding debris and debris. All water outlet points are fully exposed, allowing the location, water volume, water outlet form, and outlet shape of all water outlet points to be observed;

[0009] S3. Adjust the outlet and detect the extension direction of the water outlet channel: Use a jackhammer, hammer, or steel chisel to make appropriate adjustments to the outlet. Use steel bars or wooden sticks to detect the extension direction of the water outlet channel from the outlet inward.

[0010] S4. Use pipes to collect and guide water: A water guide pipe with a certain depth and strength for guiding and collecting water is inserted from the water outlet. The outer diameter of the water guide pipe should match the water outlet as much as possible. Then, the gap between the water guide pipe and the water outlet is effectively filled to ensure that the gap is leak-proof and the water is completely concentrated in the water guide pipe for outflow. This step requires that all water outlet points be treated as water guides.

[0011] S5. Connecting water pipes: Connect the water pipes. The length of the water pipes should be greater than the burial depth of the underground engineering base and greater than the height of the water source. Connect the tail ends of all water pipes to the suspension ropes.

[0012] S6. Flooding the underground space: Stop draining the underground works and use the water from the underground works to gradually flood the underground space until the water level is completely stable.

[0013] S7. Lift the tail section of the water pipe out of the water: Use the suspension rope to lift the water pipe out of the water;

[0014] S8. Grouting using the water conduit: The water conduit is connected to the grouting pipeline for grouting. The slurry enters the water conduit channel through the water conduit, thereby sealing the water outlet and the water conduit channel.

[0015] S9. Pumping out water from underground spaces: After the slurry has fully solidified, pump out all water from underground spaces, cut off the water pipes, and complete the sealing of water gushing points in underground projects.

[0016] Preferably, in step S1, the actual drainage capacity of the drainage system must be greater than the water flow of the underground project, and the head must be greater than the burial depth of the underground project.

[0017] Preferably, in step S2, when the water outlet is corrected, it is corrected to a relatively regular shape as much as possible, such as an approximately circular or elliptical shape.

[0018] Preferably, in steps S4-S7, the water conduit is always in an open state.

[0019] Preferably, in step S4, cotton yarn or a woven bag stained with flocculation slurry is used to effectively fill the gap between the water conduit and the water outlet.

[0020] Preferably, in step S4, the flocculation slurry is cement-water glass two-liquid slurry or two-component urea-formaldehyde resin slurry.

[0021] Preferably, in step S8, ordinary cement slurry is preferably used for grouting. If the grouting amount is too large, water glass can be appropriately added to replace the grouting with cement-water glass double liquid slurry, or directly replace the grouting with chemical slurry.

[0022] The beneficial effects of the present invention are:

[0023] The core of the present invention is to use water pipes to guide and collect water at the water outlet point, and then use the underground project's own water to flood the underground space. In this way, when using the water pipes for grouting treatment, the underground space's own accumulated water can be relied upon to offset the grouting pressure to a certain extent, relatively reducing the effect of the grouting pressure on the rock formation near the water outlet point. While ensuring the effective diffusion of the slurry, it can also prevent the damage to the base rock formation, thereby ensuring the safety and effectiveness of the treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 A schematic diagram of a water outlet point exposed after drainage of an underground project provided by an embodiment of the present invention;

[0026] Figure 2 A schematic diagram of connecting water pipes provided in an embodiment of the present invention;

[0027] Figure 3 A schematic diagram of grouting a water guide pipe according to an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the underground space after water is pumped out according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] This embodiment provides a method for treating relatively concentrated water inrush in underground projects. The specific steps are as follows: ① Drain the underground project and expose the water point. Figure 1 →② Cleaning the underground engineering base →③ Repairing the water outlet and detecting the extension direction of the water outlet channel →④ Using pipes to collect and guide water →⑤ Connecting the water pipe (for installation of water pipe, refer to Figure 2 )→⑥Flood the underground space→⑦The tail end of the water pipe is raised to the surface→⑧Use the water pipe for grouting (see Figure 3 )→⑨ Pumping out water from underground space (see Figure 4 ).

[0031] Take the shield machine receiving and sending foundation pit at the intersection of Metro Line 4 in a certain city as an example. The depth is 30m, the length and width are 40m, the upper 10m is a loose layer, and the lower 20m is a limestone layer. The limestone layer is highly water-rich and has developed cracks. When the foundation pit was constructed to a depth of 30m, the base rock structure was poor, revealing three main water gushing points, all of which were wide cracks, approximately elliptical, with a total water gushing flow of 1500m. 3 / h, with a daily drainage of 36,000m 3 The daily drainage cost reached 36,000 yuan.

[0032] First, on the basis of pumping out the gushing and accumulating water in the foundation pit, personnel and machinery entered the base, surveyed the water outlet, and corrected the water outlet. The correction was mainly done with a jackhammer, and the outlet was corrected into an approximate circle. Steel bars were inserted into the outlet to explore the extension direction of the water outlet channel. It was found that the extension directions of the water outlet channels were different, but the overall shape was relatively regular and the channel was unobstructed.

[0033] A thick-walled corrugated pipe with a diameter roughly matching the outlet diameter was used as the water guide pipe. Corrugated pipes of corresponding diameters, 2.1m, 1.5m, and 1.4m deep, were lowered into the three outlet points. The gap between the corrugated pipe and the outlet was densely filled with discarded cement woven bags soaked in cement-water glass slurry to a depth exceeding 1.0m. The corrugated pipe was then connected to a length of 40m, and a steel wire rope was connected to the ground at the end of the corrugated pipe.

[0034] After stopping the foundation pit drainage for about 50 hours, the water level in the foundation pit was basically stable, and the water depth reached 25m. The end of the bellows was lifted out of the water surface by connecting the steel wire rope to the tail of the bellows, and fixed at the edge of the foundation pit. The grouting pump was connected to the bellows, and grouting was carried out on each bellows one by one (see Figure 3, grouting in the water pipe), initially inject single-liquid cement slurry, after deducting the volume of slurry in the corrugated pipe, the cement slurry consumption at a single water point reaches 15m 3 , then add about 5% of the volume of water glass to the cement slurry, but the water point has grouting up to 10m 3 After that, grouting was stopped, and it was predicted that the grouting would block the outlet channel for more than 20m;

[0035] See also Figure 4 48 hours after the grouting was completed, the slurry was fully solidified and the accumulated water in the foundation pit was drained. No water was found at the bottom of the well. The water-conducting bellows were cut off, and the treatment of multiple relatively concentrated water gushing at the bottom of the foundation pit was completed.

[0036] The present invention uses a water pipe to guide and collect water at the water outlet point, and then uses the underground project's own water to flood the underground space. In this way, when using the water pipe for grouting treatment, the underground space's own accumulated water can be relied upon to offset the grouting pressure to a certain extent, relatively reducing the effect of the grouting pressure on the rock formation near the water outlet point. While ensuring the effective diffusion of the slurry, it can also prevent the damage to the basement rock formation, thereby ensuring the safety and effectiveness of the treatment.

[0037] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A method for treating relatively concentrated water inrush in underground engineering, characterized in that: The following steps are involved: S1. Drainage of underground projects to expose water outlets: Use the drainage system to continuously pump out the accumulated and gushing water in underground projects to fully expose the water outlets at the base; S2. Cleaning the underground engineering base: After the accumulated water and gushing water are continuously pumped out to the base, the water outlet points of the underground engineering base are cleaned, and all water outlet points are completely exposed, so that the location, water volume, water outlet form and shape of all water outlet points can be observed; S3. Water outlet trimming and outlet channel extension direction detection: Make appropriate corrections to the water outlet and detect the extension direction of the outlet channel from the water outlet inward; S4. Use pipes to collect and guide water: Insert a water pipe of a certain depth from the water outlet to guide and accumulate water. The outer diameter of the water pipe should match the water outlet as much as possible. Then, effectively fill the gap between the water pipe and the water outlet to ensure that the gap is leak-proof and the water is completely collected in the water pipe for outflow. This step requires that all water outlet points be treated with water. S5. Connecting water pipes: Connect the water pipes. The length of the water pipes should be greater than the burial depth of the underground engineering base and greater than the height of the water source. Connect the tail ends of all water pipes to the suspension ropes. S6. Flooding the underground space: Stop draining the underground works and use the water from the underground works to gradually flood the underground space until the water level is completely stable. S7. Lift the tail section of the water pipe out of the water: Use the suspension rope to lift the water pipe out of the water; S8. Grouting using the water conduit: The water conduit is connected to the grouting pipeline for grouting. The slurry enters the water conduit channel through the water conduit, thereby sealing the water outlet and the water conduit channel. S9. Pumping out water from underground spaces: After the slurry has fully solidified, pump out all water from underground spaces, cut off the water pipes, and complete the sealing of water gushing points in underground projects.

2. A method for treating relatively concentrated water inrush in underground engineering according to claim 1, characterized in that: In step S1, the actual drainage capacity of the drainage system must be greater than the water flow of the underground project, and the head must be greater than the burial depth of the underground project.

3. A method for treating relatively concentrated water inrush in underground engineering according to claim 1, characterized in that: In step S2, when the water outlet is corrected, it is corrected into a circular or elliptical shape.

4. A method for treating relatively concentrated water inrush in underground engineering according to claim 1, characterized in that: In steps S4-S7, the water conduit is always in an open state.

5. The method for treating relatively concentrated water inrush in underground engineering according to claim 1, characterized in that: In step S4, cotton yarn or woven bags soaked in flocculation slurry are used to effectively fill the gap between the water pipe and the water outlet.

6. A method for treating relatively concentrated water inrush in underground engineering according to claim 5, characterized in that: In step S4, the flocculation slurry is a cement-water glass two-liquid slurry or a two-component urea-formaldehyde resin slurry.

7. A method for treating relatively concentrated water inrush in underground engineering according to claim 1, characterized in that: In step S8, ordinary cement slurry or cement-water glass double liquid slurry is used for grouting.

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