A method for treating water leakage in subway station structures by negative pressure traction grouting

Abstract

The present invention relates to the technical field of rail transit structural defect repair, and in particular to a method for treating water leakage in a subway station structure by negative pressure traction grouting. The method comprises the following steps: Step 1: Arranging grouting holes and negative pressure holes: Setting grouting holes at the leakage location for grouting and plugging the leakage location, and setting a plurality of negative pressure holes around the grouting holes; Step 2: Equipment installation: Connecting the grouting port of the grouting equipment with the opened grouting holes, and connecting the negative pressure equipment to the negative pressure holes; Step 3: Starting negative pressure traction: Starting the negative pressure equipment to pump water from the negative pressure holes, and starting step 4 when the pumped leakage water contains impurities; Step 4: Grouting: Maintaining negative pressure traction, starting the grouting equipment; When the negative pressure hole starts to flow out grouting liquid, reducing the traction power of the negative pressure equipment; Then, when the grouting liquid stably flows out of the negative pressure hole, turning off the negative pressure traction; Finally, continuing grouting until the slurry overflows from the defective part.

Description

Technical Field

[0001] The invention relates to the technical field of rail transit structure defect repair, in particular to a method for treating water leakage in a subway station structure through negative pressure traction grouting. Background Art

[0002] In recent years, with the continuous rise of groundwater levels in some cities, the external environment of some stations has changed from a water-free state to a water-rich state. As a result, water leakage in stations has increased significantly. If not handled promptly and effectively, it will not only affect equipment operation and passenger travel, but in serious cases, it will even affect structural safety and reduce service life. Therefore, when water leakage occurs in subway underground stations, relevant agencies will take appropriate measures;

[0003] At present, grouting is the main method for treating structural water leakage. Generally, high-pressure grouting equipment is used to forcibly inject slurry into the diseased area to form a water-stopping barrier. It has the advantages of simple operation, strong applicability, and good treatment effect. Although this method can quickly treat structural water leakage, it still has obvious shortcomings in treating structural water leakage in a water-rich environment: the water-rich environment causes pore water pressure inside the leakage area of ​​the structure. The existing grouting method relies on the reaction of grouting liquid with water to reduce part of the water pressure on the one hand, and relies on grouting pressure to squeeze out the water on the other hand. This makes it impossible for the grouting liquid to enter the tiny main cracks in a short time. The grouting pressure has reached the limit value and the grouting needs to be terminated, resulting in reduced grouting quality. The formed waterproof barrier is small in area and prone to leakage again. It cannot completely solve the problem of structural leakage. At the same time, in order to achieve the grouting effect, it is usually necessary to arrange multiple grouting holes, which causes certain damage to the structure. Summary of the Invention

[0004] The invention discloses an anti-leakage negative pressure traction grouting method.

[0005] The technical problem to be solved is: when the underground structure surface is leaking in the ascites state, it is difficult to inject the grouting liquid for repairing the leakage into the tiny cracks at the leakage site by simply using pressure grouting, resulting in incomplete leakage repair.

[0006] In order to solve the above technical problems, the present invention provides an anti-leakage negative pressure traction grouting method, which adopts the following scheme.

[0007] A leakage-proof negative pressure traction grouting method is used to grout and seal structural leakage in a water-rich state on an underground structural surface. The method comprises the following steps:

[0008] Step 1: Arrange grouting holes and negative pressure holes: Set grouting holes at the leakage location to grout and seal the leakage, and set several negative pressure holes around the grouting holes;

[0009] Step 2 Equipment installation: Connect the grouting port of the grouting equipment to the opened grouting hole, and connect the negative pressure equipment to the negative pressure hole.

[0010] Step 3: Start negative pressure traction: Start the negative pressure equipment to pump water from the negative pressure hole. When the pumped out leaking water contains impurities, start step 4.

[0011] Step 4: Grouting: Maintain negative pressure traction and start the grouting equipment; when the grouting liquid begins to flow out of the negative pressure hole, reduce the traction power of the negative pressure equipment; then when the grouting liquid flows steadily out of the negative pressure hole, turn off the negative pressure traction; finally, continue grouting until the slurry overflows from the diseased area.

[0012] Preferably, before step 1, the leakage location is first checked and marked; the leakage inspection can be performed by manual observation and / or address radar equipment.

[0013] Preferably, after the grouting holes and negative pressure holes are arranged in step 1 and before the equipment is installed in step 2, the grouting holes and negative pressure holes are cleaned by using a high-pressure air gun or a high-pressure water gun to clean the inside of the grouting holes and negative pressure holes.

[0014] Preferably, the leakage includes point leakage, linear leakage and surface leakage;

[0015] For point leakage, 3-6 negative pressure holes are set in a circular pattern with the leakage point as the center, and the negative pressure holes are 20-50 cm away from the leakage point;

[0016] For linear leakage, a grouting hole is set in the middle of the main crack or several grouting holes are set at intervals along the main crack; several negative pressure holes are set at intervals along the main crack on both sides of the main crack, with the spacing between adjacent negative pressure holes on the same side being 15-50 cm, and the distance between the negative pressure holes and the main crack being 15-50 cm; negative pressure holes are set 15-50 cm outside each end of the main crack;

[0017] For surface leakage, a grouting hole is set in the middle of the surface leakage, or multiple grouting holes are set in a grid pattern inside the surface leakage; multiple negative pressure holes are set around the surface leakage at intervals, and the spacing between the negative pressure holes is 10-30cm.

[0018] Preferably, in step 3, the negative pressure device is turned on to simultaneously pump air / water from all negative pressure holes;

[0019] Leakage includes point leakage, linear leakage and surface leakage;

[0020] For negative pressure holes with point leakage, pump at a power of 0.8-1.2 L / s for 1-3 minutes;

[0021] For negative pressure holes with line leakage, pump at a power of 1.2-1.6 L / s for 2-3 minutes;

[0022] For negative pressure holes with surface leakage, pump at a power of 0.3-0.7 L / s for 1.8-2.2 minutes.

[0023] Preferably, in step 4, the leakage includes point leakage, linear leakage and surface leakage; for point leakage, start pressure grouting while maintaining the power of negative pressure traction at 1L / s, and maintain the grouting pressure at 0.1-0.3MPa. When the grouting liquid begins to flow out of the negative pressure hole, reduce the power of the negative pressure equipment to 20-50%. When the grouting liquid flows stably out of the negative pressure hole, turn off the negative pressure traction and continue grouting until the slurry overflows from the diseased part.

[0024] Preferably, in step 4, for line leakage, maintain the power of negative pressure traction at 1.2-1.6 L / s while starting pressure grouting, and maintain the grouting pressure at 0.1-0.3 MPa. When slurry flows out of one or all of the negative pressure holes, first reduce the power of the negative pressure equipment on both sides of the main crack to 40-60%;

[0025] Continue grouting until the slurry stably flows out of the negative pressure holes at both ends of the main crack, reduce the power of the negative pressure equipment at both ends of the main crack to 20-40%, and at the same time reduce the power of the negative pressure equipment on both sides of the main crack to 20-40%;

[0026] When the grouting is completed and the slurry is stably flowing out from all the negative pressure holes, turn off the negative pressure traction and continue grouting until the slurry is stably overflowing from the main cracks.

[0027] Preferably, in step 4, for surface leakage, pressure grouting is started while maintaining the power of negative pressure traction at 0.3-0.6L / s, and the grouting pressure is maintained at 0.1-0.3MPa. When all negative pressure holes begin to flow out of grouting liquid, the power of the negative pressure equipment is reduced to 20-40%, and grouting is continued until the slurry flows out stably from any negative pressure hole, and then the negative pressure traction is turned off, and grouting is continued until the grouting liquid overflows in a point-like manner in the leakage area.

[0028] Preferably, in step 4, for planar leakage, after the grouting is completed, the injected grouting liquid is waited for initial solidification and shrinkage, and then secondary grouting is performed.

[0029] Preferably, after the grouting in step 4 is completed, surface treatment is performed, the grouting equipment and negative pressure equipment are removed, and after the grouting liquid is completely solidified, the water stop needles are removed and the surface is cleaned and treated to restore the original state.

[0030] Compared with the prior art, the anti-leakage negative pressure traction grouting method of the present invention has the following beneficial effects:

[0031] The water-rich environment at the leaking site creates numerous tiny cracks within the site. The water trapped within these cracks creates a barrier, hindering the grouting solution needed to repair the leak from entering the cracks. Therefore, prior to grouting, the present invention applies negative pressure to the leaking site to extract the water and slurry from the cracks, temporarily freeing the leaking site from its water-rich state. This allows the grouting solution to flow smoothly into the cracks.

[0032] And during the grouting process, negative pressure traction is continuously carried out, the grouting holes are squeezed with high pressure, and the negative pressure holes are pulled with negative pressure. On the one hand, it allows the grouting liquid to flow into the cracks that cannot be flowed by relying solely on high-pressure grouting, and on the other hand, it allows the grouting liquid to flow into the cracks faster. At the same time, in order to prevent the grouting liquid from being extracted by the negative pressure traction equipment, the power of the negative pressure equipment is first reduced when the grouting liquid begins to flow out of the negative pressure hole, and then the negative pressure traction is turned off until the grouting liquid flows out of the negative pressure hole stably. And the grouting pressure is maintained until the grouting liquid overflows from the diseased area. This indicates that the grouting liquid has filled the surrounding cracks. At the same time, it can avoid the secondary damage to the structure that may be caused by the local grouting mass pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of a leakage-proof negative pressure traction grouting method for point leakage according to the present invention;

[0034] Figure 2 It is a schematic diagram of the present invention for linear leakage;

[0035] Figure 3 It is a schematic diagram of the present invention for planar leakage.

[0036] Explanation of the accompanying numbers: 1-structure surface, 2-leakage point, 3-crack, 4-damaged part, 5-grouting hole, 6-negative pressure hole. DETAILED DESCRIPTION

[0037] The following describes the specific embodiments of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0038] In the present invention, unless otherwise stated, directional words such as "up, down, left, right" generally refer to the directions in the attached drawings. Figure 1 The upper, lower, left and right shown in the figure; "inside" and "outside" refer to the inside and outside relative to the outline of each component itself. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0039] In order to solve the problem of structural leakage of underground structural surfaces in the ascites state, it is difficult to inject the grouting liquid for repairing the leakage into the tiny cracks 3 at the leakage site by pressure grouting alone, resulting in the problem of poor leakage repair. The present invention proposes a leakage-proof negative pressure traction grouting method.

[0040] A leakage-proof negative pressure traction grouting method is used to grout and seal structural leakage in a water-rich underground structure. The method comprises the following steps:

[0041] Step 1: Arrange grouting holes 5 and negative pressure holes 6: Arrange grouting holes 5 at the leakage location to grout and seal the leakage, and arrange several negative pressure holes 6 around the grouting holes 5;

[0042] Step 2 Equipment installation: Connect the grouting port of the grouting equipment to the opened grouting hole 5, and connect the negative pressure equipment to the negative pressure hole 6.

[0043] Step 3: Start negative pressure traction: Start the negative pressure equipment to pump water from the negative pressure hole 6. When the pumped leaked water contains impurities, start step 4.

[0044] Step 4: Grouting: Maintain negative pressure traction and start the grouting equipment; when the grouting liquid begins to flow out of the negative pressure hole 6, reduce the traction power of the negative pressure equipment; then when the grouting liquid flows steadily out of the negative pressure hole 6, turn off the negative pressure traction; finally, continue grouting until the slurry overflows from the diseased part 6.

[0045] The grouting equipment is no different from the traditional grouting and leak-proof equipment. During installation, the grouting water-stop needle is installed in the grouting hole 5 and the grouting equipment is connected. The negative pressure equipment is a water pump. The surface seal of the negative pressure equipment and the negative pressure hole 6 needs to be set to avoid air leakage. In step 3, the negative pressure equipment will pump air outward while pumping water, and the water pumped out at the beginning is the water stored in the rear crack 3, which is generally clear. When impurities such as mud, sand, and small stones begin to appear in the water, it means that the water stored in the crack 3 is basically drained, and the crack 3 is mainly air.

[0046] In step 4, due to the traction of the negative pressure device, the injected grouting liquid will first flow from the injection hole through the crack 3 to the negative pressure hole 6. When the grouting liquid begins to flow out of the negative pressure hole 6, the traction power of the negative pressure device should be reduced to prevent a large amount of grouting liquid from being drawn to the negative pressure hole 6, resulting in the cracks 3 in other locations not being effectively filled. Then, when the negative pressure hole 6 begins to steadily flow out of the grouting liquid, the negative pressure device should be turned off. This continues until the grouting is completed, that is, the grouting liquid overflows from the defective location.

[0047] Before step 1, the leakage location should be checked and marked. The leakage inspection can be carried out by manual observation and / or address radar equipment.

[0048] After the grouting holes 5 and the negative pressure holes 6 are laid out in step 1, and before the equipment is installed in step 2, the grouting holes 5 and the negative pressure holes 6 are cleaned by using a high-pressure air gun or a high-pressure water gun to clean the inside of the grouting holes 5 and the negative pressure holes 6.

[0049] In step 3, the negative pressure device is turned on to simultaneously pump air / water from all the negative pressure holes 6 .

[0050] After the grouting is completed in step 4, the surface treatment is carried out, the grouting equipment and the negative pressure equipment are removed, and after the grouting liquid is completely solidified, the water stop needle is removed and the surface is cleaned and treated to restore the original state. If the grouting liquid fails to completely and effectively block the grouting hole 5 and the negative pressure hole 6 due to flow or shrinkage problems, the grouting hole 5 and the negative pressure landfill need to be sealed by surface treatment.

[0051] like Figures 1 to 3 As shown in , leakage includes point leakage, linear leakage and surface leakage.

[0052] For point leakage Figure 1 :

[0053] In step 1, 3-6 negative pressure holes 6 are arranged in a circular pattern with the leakage point 2 as the center, and the negative pressure holes 6 are distributed in a cross shape around the grouting hole 5. The pressure holes are 220-50 cm away from the leakage point, preferably 30 cm.

[0054] In step 3, the negative pressure hole 6 is pumped at a power of 0.8-1.2 L / s for 1-3 minutes.

[0055] In step 4, pressure grouting is started while maintaining the power of negative pressure traction at 1 L / s. The grouting pressure is maintained at 0.1-0.3 MPa. When the grouting liquid begins to flow out of the negative pressure hole 6, the power of the negative pressure equipment is reduced to 20-50%. When the grouting liquid flows steadily out of the negative pressure hole 6, the negative pressure traction is turned off and grouting is continued until the slurry overflows from the diseased part 6.

[0056] For surface leakage Figure 2 :

[0057] In step 1, a grouting hole 5 is set in the middle of the main crack or several grouting holes 5 are set at intervals along the main crack. The number and spacing of the grouting holes 5 can be calculated based on the actual main crack width and length. Several negative pressure holes 6 are set at intervals along the main crack on both sides of the main crack, with the spacing between adjacent negative pressure holes 6 on the same side being 15-50 cm, and the distance between the negative pressure holes 6 and the main crack being 15-50 cm. Negative pressure holes 6 are set at 15-50 cm outside the two ends of the main crack.

[0058] In step 3, for the negative pressure hole 6 with line leakage, pump at a power of 1.2-1.6 L / s for 2-3 minutes.

[0059] In step 4, first, maintain the power of negative pressure traction at 1.2-1.6 L / s while starting pressure grouting, and maintain the grouting pressure at 0.1-0.3 MPa. When slurry flows out of one or all of the negative pressure holes 6, first reduce the power of the negative pressure equipment on both sides of the main crack to 40-60%;

[0060] Continue grouting until the slurry stably flows out of the negative pressure holes 6 at both ends of the main crack, reduce the power of the negative pressure equipment at both ends of the main crack to 20-40%, and at the same time reduce the power of the negative pressure equipment on both sides of the main crack to 20-40%;

[0061] When the grouting is continued until the slurry stably flows out from all the negative pressure holes 6, the negative pressure traction is turned off and the grouting is continued until the slurry stably overflows from the main cracks.

[0062] For surface leakage Figure 3 :

[0063] In step 1, a grouting hole 5 is set in the middle of the surface leakage, or multiple grouting holes 5 are set in a grid pattern inside the surface leakage; multiple negative pressure holes 6 are set around the surface leakage at intervals, and the spacing between the negative pressure holes 6 is 10-30 cm.

[0064] In step 3, for the negative pressure hole 6 of the surface leak, pump at a power of 0.3-0.7 L / s for 1.8-2.2 minutes.

[0065] In step 4, pressure grouting is started while maintaining the power of negative pressure traction at 0.3-0.6L / s, and the grouting pressure is maintained at 0.1-0.3MPa. When all negative pressure holes 6 begin to flow out of the grouting liquid, the power of the negative pressure equipment is reduced to 20-40%, and grouting is continued until the slurry stably flows out from any negative pressure hole 6. Then, the negative pressure traction is turned off and the grouting is continued until the grouting liquid overflows in the leakage area. After the grouting is completed, wait for the injected grouting liquid to initially solidify and shrink, and then perform secondary grouting. Secondary grouting can be used to seal the gaps that are not tightly plugged due to the shrinkage of the grouting liquid after the first grouting.

[0066] Figure 1 The structural surface 1 is generally the surface of the concrete wall of an underground station or a tunnel. The diseased area 4 is the area where moisture is caused by leakage.

[0067] The embodiments described above are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A method for preventing leakage by negative pressure traction grouting, which is used to grout and seal structural leakage in a water-rich underground structure, comprising the following steps: Step 1: Arrange grouting holes (5) and negative pressure holes (6): Arrange grouting holes (5) at the leakage location for grouting and plugging the leakage location, and arrange a number of negative pressure holes (6) around the grouting holes (5); Step 2: Equipment installation: connect the grouting port of the grouting equipment to the opened grouting hole (5), and connect the negative pressure equipment to the negative pressure hole (6); Step 3: Start negative pressure traction: Start the negative pressure equipment to pump water from the negative pressure hole (6), and start step 4 when the pumped out leaking water contains impurities; Step 4: Grouting: Maintain negative pressure traction and start the grouting equipment; when the grouting liquid begins to flow out of the negative pressure hole (6), reduce the traction power of the negative pressure equipment; then, when the grouting liquid stably flows out of the negative pressure hole (6), turn off the negative pressure traction; finally, continue grouting until the grouting liquid overflows from the diseased part (4); Leakage includes point leakage, linear leakage and surface leakage; In step 4, for point leakage, start pressure grouting while maintaining the power of negative pressure traction at 1L / s, and keep the grouting pressure at 0.1-0.3MPa. When the grouting liquid starts to flow out of the negative pressure hole (6), reduce the power of the negative pressure equipment to 20-50%. When the grouting liquid flows out stably from the negative pressure hole (6), turn off the negative pressure traction and continue grouting until the grouting liquid overflows from the diseased part (4); In step 4, for line leakage, maintain the power of negative pressure traction at 1.2-1.6L / s while starting pressure grouting, and keep the grouting pressure at 0.1-0.3MPa. When slurry flows out of one or all of the negative pressure holes (6), first reduce the power of the negative pressure equipment on both sides of the main crack to 40-60%; Continue grouting until the slurry stably flows out from the negative pressure holes (6) at both ends of the main crack (3), reduce the power of the negative pressure equipment at both ends of the main crack (3) to 20-40%, and at the same time reduce the power of the negative pressure equipment on both sides of the main crack (3) to 20-40%; When the grouting is continued until the slurry stably flows out from all the negative pressure holes (6), the negative pressure traction is turned off and the grouting is continued until the slurry stably overflows from the main crack (3).

2. The anti-leakage negative pressure traction grouting method according to claim 1, characterized in that: Before step 1, first check the leakage location and mark it; Leak detection can be carried out by manual observation and / or geological radar equipment.

3. The anti-leakage negative pressure traction grouting method according to claim 1, characterized in that: After the grouting holes (5) and negative pressure holes (6) are laid out in step 1, and before the equipment is installed in step 2; The grouting hole (5) and the negative pressure hole (6) are cleaned by using a high-pressure air gun or a high-pressure water gun to clean the inside of the grouting hole (5) and the negative pressure hole (6).

4. The anti-leakage negative pressure traction grouting method according to claim 1, characterized in that: Leakage includes point leakage, linear leakage and surface leakage; For point leakage, 3-6 negative pressure holes (6) are arranged in a circular pattern with the leakage point (2) as the center, and the negative pressure holes (6) are 20-50 cm away from the leakage point (2); For linear leakage, a grouting hole (5) is set in the middle of the main crack or several grouting holes (5) are set at intervals along the main crack; several negative pressure holes (6) are set at intervals along the main crack on both sides of the main crack, with the spacing between adjacent negative pressure holes (6) on the same side being 15-50 cm, and the distance between the negative pressure holes (6) and the main crack being 15-50 cm; and negative pressure holes (6) are set at 15-50 cm outside the two ends of the main crack; For surface leakage, a grouting hole (5) is provided in the middle of the surface leakage, or a plurality of grouting holes (5) are provided in a grid pattern within the surface leakage; and a plurality of negative pressure holes (6) are provided at intervals around the surface leakage, with the spacing between the negative pressure holes (6) being 10-30 cm.

5. The anti-leakage negative pressure traction grouting method according to claim 1, characterized in that: In step 3, the negative pressure device is turned on to simultaneously pump air / water from all negative pressure holes (6); Leakage includes point leakage, linear leakage and surface leakage; For point-like leakage of negative pressure holes (6), pump at a power of 0.8-1.2 L / s for 1-3 minutes; For the negative pressure hole (6) with line leakage, pump at a power of 1.2-1.6 L / s for 2-3 minutes; For the negative pressure hole (6) with surface leakage, pump at a power of 0.3-0.7 L / s for 1.8-2.2 minutes.

6. The anti-leakage negative pressure traction grouting method according to claim 1, characterized in that: Leakage includes point leakage, linear leakage and surface leakage; In step 4, for surface leakage, pressure grouting is started while maintaining the power of negative pressure traction at 0.3-0.6L / s, and the grouting pressure is maintained at 0.1-0.3MPa. When all negative pressure holes (6) begin to flow out grouting liquid, the power of the negative pressure equipment is reduced to 20-40%, and grouting is continued until the slurry flows out stably from any negative pressure hole (6). Then, the negative pressure traction is turned off and grouting is continued until the grouting liquid overflows in a point-like manner in the leakage area.

7. The anti-leakage negative pressure traction grouting method according to claim 6, characterized in that: In step 4, for surface leakage, after the grouting is completed, wait for the injected grouting liquid to initially solidify and shrink, and then perform secondary grouting.

8. The anti-leakage negative pressure traction grouting method according to claim 1, characterized in that: After the grouting in step 4 is completed, the surface treatment is carried out. Remove the grouting equipment and negative pressure equipment, wait for the grouting liquid to completely solidify, remove the water stop needle and clean the surface to restore it to its original state.

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