A deep foundation pit combined grouting and plugging device and process

Abstract

The present invention discloses a deep foundation pit combined grouting and plugging device and process, characterized by comprising two sets of parallel and spaced steel pipes, the two sets of steel pipes being connected via multiple sets of connecting assemblies; the steel pipes comprising a first steel pipe and a second steel pipe, the first steel pipe having a grouting valve at its bottom and three sets of grouting valves on the second steel pipe, the three sets of grouting valves on the second steel pipe being spaced from bottom to top, the vertical spacing between the grouting valves of the first steel pipe and the grouting valve at the bottom of the second steel pipe being greater than or equal to 1 meter; the vertical spacing between adjacent grouting valves on the second steel pipe being greater than or equal to 1.5 meters; the outer surfaces of the grouting valves being provided with multiple sets of grouting holes, each set of grouting holes being coated with a set of elastic sealing rubber rings; and each set of grouting holes of the topmost set of grouting valves on the second steel pipe being coated with two sets of elastic sealing rubber rings. The present invention improves plugging efficiency and quality.

Description

Technical Field

[0001] The present invention relates to the field of foundation construction, and in particular to a deep foundation pit combined grouting and plugging device and process. Background Art

[0002] During construction, the more conventional method is to use deep foundation pits for piling. However, it is also common for deep foundation pits to leak. Conventional sealing methods generally use quick-setting cement for sealing. However, if it is simply sealed, after a period of leakage, there will be sediment loss, resulting in some holes and poor firmness. Generally, fillers are directly inserted into larger holes for filling, and other invisible places are generally not processed. Moreover, filling uses another set of equipment and another set of processes, which is very inconvenient. Summary of the Invention

[0003] The purpose of the present invention is to provide a deep foundation pit combined grouting and plugging device and process. By using this structure and process, the plugging efficiency and effect are improved. On the basis of plugging, reinforcement is further carried out to improve the safety of subsequent processing.

[0004] To achieve the above-mentioned object, the technical solution adopted by the present invention is: a deep foundation pit joint grouting and plugging device, comprising two groups of steel pipes arranged parallel to each other and spaced apart, the two groups of steel pipes being connected via multiple groups of connecting components; the steel pipes comprising a first steel pipe and a second steel pipe, the bottom of the first steel pipe being provided with a grouting valve, the second steel pipe being provided with three groups of grouting valves, the three groups of grouting valves on the second steel pipe being spaced apart from bottom to top, and one group of grouting valves being provided at the bottom of the second steel pipe, the vertical spacing between the grouting valve of the first steel pipe and the grouting valve at the bottom of the second steel pipe being greater than or equal to 1 meter; the vertical spacing between adjacent grouting valves on the second steel pipe being greater than or equal to 1.5 meters;

[0005] The outer surface of the grouting valve is provided with multiple groups of grouting holes, and each group of grouting holes is covered with a group of elastic sealing rubber rings; and each group of grouting holes of the grouting valve at the top of the second steel pipe is covered with two groups of elastic sealing rubber rings.

[0006] In the above technical solution, the grouting valve is a hollow structure with openings at both ends. A through groove is provided in the middle of the grouting valve, and the two ends of the through groove are respectively connected to the two ends of the grouting valve; and the outer surfaces of the two ends of the grouting valve are respectively provided with external threads.

[0007] In the above technical solution, a plurality of annular grooves are provided on the outer surface of the grouting valve from top to bottom, the grouting hole is provided on the outer wall of the annular groove, and the inner end of the grouting hole is connected to the through groove, and the elastic sealing rubber ring is provided in the annular groove.

[0008] In the above technical solution, the bottom of the grouting valve at the bottom of the first steel pipe and the second steel pipe is screwed with a plug.

[0009] In the above technical solution, the first steel pipe is arranged flush with the top of the second steel pipe, the second steel pipe includes an upper steel pipe, a middle steel pipe and a lower steel pipe, the lower steel pipe connects the two groups of grouting valves below, the middle steel pipe connects the top grouting valve with the middle grouting valve, and the bottom of the upper steel pipe is connected to the top grouting valve.

[0010] In the above technical solution, the wall thickness of the elastic sealing rubber ring is 2 mm.

[0011] In the above technical solution, multiple groups of connecting components are arranged at intervals from top to bottom, and the connecting components include a first ring and a second ring that are connected to each other. The middle part of the first steel pipe is inserted into the first ring, and the middle part of the second steel pipe is inserted into the second ring. The first steel pipe is welded to the second ring, and the second steel pipe is welded to the second ring.

[0012] To achieve the above object, the present invention adopts a deep foundation pit combined grouting and plugging process, the steps of which are as follows:

[0013] ① During the process of assembling the grouting pipe with the first steel pipe and the second steel pipe respectively, the first steel pipe and the second steel pipe are connected by using a connecting assembly;

[0014] ②Insert the first and second steel pipes into the leaking deep foundation pit until they reach the corresponding depth;

[0015] ③Inject water glass into the first steel pipe at a flow rate of 30L / min. The water glass flows out from the grouting holes of the grouting valve at the bottom of the first steel pipe and continues for 10 minutes. Then, while the first steel pipe continues to inject water glass, the second steel pipe injects cement slurry. The cement slurry flows out from the grouting holes of the two groups of grouting valves at the bottom of the second steel pipe. The injection flow rate of cement slurry is the same as that of water glass. Observe the leakage points inside the deep foundation pit until the leakage stops.

[0016] ④ After the leaking point stops leaking, continue to inject water glass and cement slurry at the same flow rate for 30 minutes, and then stop injecting water glass and cement slurry;

[0017] ⑤ After the injection of water glass and cement slurry stops for 10 minutes, inject clean water into the second steel pipe to open the second steel pipe filled with cement slurry;

[0018] ⑥ After the second steel pipe is opened, increase the water injection pressure and use clean water to open the grouting hole of the top grouting pipe, so that the clean water flows out from the grouting hole of the top grouting valve, and continue for 1 minute;

[0019] ⑦ Stop injecting clean water into the second steel pipe, and then inject cement slurry into the second steel pipe. The cement content in the injected cement slurry is 10t~50t. Use the cement slurry to reinforce the upper loose and hollow soil.

[0020] In the above technical solution, the ratio of water to cement in the cement slurry is 1:1.

[0021] In the above technical solution, the grouting hole of the top grouting valve of the second steel pipe is covered with two layers of elastic sealing rubber rings, and the grouting holes of the two groups of grouting valves at the bottom and the grouting valve at the bottom of the first steel pipe are covered with a layer of elastic sealing rubber ring. The grouting bearing pressure of the single-layer elastic sealing rubber ring is 0.15MPa, and the grouting bearing pressure of the double-layer elastic sealing rubber ring is 0.3MPa; in step ⑤, the water injection pressure is less than 0.3MPa, and in step ⑥, the water injection pressure is greater than 0.3MPa.

[0022] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0023] 1. The present invention adopts two sets of steel pipes for respectively injecting water glass and cement slurry, and there is a height difference between the bottoms of the two pipes. The water glass is injected in advance to find the leakage flow channel, and then the cement slurry is injected to mix the cement slurry with the water glass to form a quick-setting material to seal the leakage. Subsequently, grouting is performed again with high pressure, so that the grouting is sent out from the grouting valve at the top, and the loose and hollow soil is reinforced with cement slurry. The sealing and reinforcement processes can be completed at one time, with high efficiency and good quality, and can also improve the strength of the foundation pit and ensure the safety of subsequent construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural diagram of the first embodiment of the present invention;

[0025] Figure 2 This is a top view of the connection between the steel pipe and the connection assembly in Example 1 of the present invention;

[0026] Figure 3 1 is a cross-sectional view of the grouting valve at the bottom of the first steel pipe and the second steel pipe in Example 1 of the present invention;

[0027] Figure 4 It is a schematic cross-sectional structural diagram of a grouting valve at the top of a second steel pipe according to an embodiment of the present invention.

[0028] Among them: 1. Connecting assembly; 2. First steel pipe; 3. Second steel pipe; 4. Grouting valve; 5. Grouting hole; 6. Elastic sealing rubber ring; 7. Through groove; 8. Annular groove; 9. Plug; 10. Upper steel pipe; 11. Middle steel pipe; 12. Lower steel pipe; 13. First set of rings; 14. Second set of rings. DETAILED DESCRIPTION

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0030] Example 1: See Figures 1 to 4 As shown, a deep foundation pit combined grouting and plugging device includes two groups of steel pipes that are parallel to each other and arranged at intervals, and the two groups of steel pipes are connected via multiple groups of connecting components 1 respectively; the steel pipes include a first steel pipe 2 and a second steel pipe 3, a grouting valve 4 is provided at the bottom of the first steel pipe, and three groups of grouting valves are provided on the second steel pipe. The three groups of grouting valves on the second steel pipe are arranged at intervals from bottom to top, and one group of grouting valves is arranged at the bottom of the second steel pipe, and the vertical spacing between the grouting valve of the first steel pipe and the grouting valve at the bottom of the second steel pipe is 1 meter; the vertical spacing between adjacent grouting valves on the second steel pipe is 1.5 meters; the distance between the first steel pipe and the second steel pipe will be less than 20 mm.

[0031] A plurality of grouting holes 5 are provided on the outer surface of the grouting valve, and each group of grouting holes is covered with a group of elastic sealing rubber rings 6; and each group of grouting holes of the grouting valve at the top of the second steel pipe is covered with two groups of elastic sealing rubber rings.

[0032] To achieve the above object, the present invention adopts a deep foundation pit combined grouting and plugging process, the steps of which are as follows:

[0033] ① During the process of assembling the grouting pipe with the first steel pipe and the second steel pipe respectively, the first steel pipe and the second steel pipe are connected by using a connecting assembly;

[0034] ②Insert the first and second steel pipes into the leaking deep foundation pit until they reach the corresponding depth;

[0035] ③Inject water glass into the first steel pipe at a flow rate of 30L / min. The water glass flows out from the grouting holes of the grouting valve at the bottom of the first steel pipe and continues for 10 minutes. Then, while the first steel pipe continues to inject water glass, the second steel pipe injects cement slurry. The cement slurry flows out from the grouting holes of the two groups of grouting valves at the bottom of the second steel pipe. The injection flow rate of cement slurry is the same as that of water glass. Observe the leakage points inside the deep foundation pit until the leakage stops.

[0036] ④ After the leaking point stops leaking, continue to inject water glass and cement slurry at the same flow rate for 30 minutes, and then stop injecting water glass and cement slurry; among them, first inject water glass into the soil layer through the first steel pipe, and the water glass will automatically find the passage in the soil layer, and will also find the leaking point and the leaking channel, and then inject cement slurry. Since the distance between the first steel pipe and the second steel pipe is small, the cement slurry will first enter the soil layer when it is sent out, and will mix with the water glass, and flow along the flow direction of the water glass, thereby filling the pores in the soil layer and the leaking channel. Since the water glass and cement slurry have a quick-setting effect after mixing, after the leaking stops, continue to inject water glass and cement slurry to reinforce other places to prevent other leaks. Moreover, while the water glass and cement slurry are flowing, they will not solidify temporarily. Only the places where they no longer flow will solidify quickly.

[0037] ⑤ After the injection of water glass and cement slurry stops for 10 minutes, clean water is injected into the second steel pipe (the pressure will be less than 0.3Mpa) to open up the second steel pipe filled with cement slurry; in this process, after the injection of water glass and cement slurry stops for 10 minutes, the outside of the two groups of grouting pipes below the second steel pipe are filled with water glass and cement slurry, and the area is solidified, that is, the outside of the two groups of grouting pipes below are blocked, and clean water cannot be sent out from the two groups of grouting pipes below. However, there is only cement slurry in the second grouting pipe, which has not solidified, and clean water can open up the second grouting pipes;

[0038] ⑥ After the second steel pipe is opened, increase the water injection pressure (pressure greater than 0.3MPa), use clean water to open the grouting hole of the top grouting pipe, and make the clean water flow out from the grouting hole of the top grouting valve, and continue for 1 minute; in this way, the grouting outlet of the grouting hole above the top grouting valve is opened.

[0039] ⑦ Stop injecting clean water into the second steel pipe, and then inject cement slurry into the second steel pipe. The cement content of the injected cement slurry is 10t~50t. Use the cement slurry to reinforce the loose and hollow soil in the upper layer. The water-to-cement ratio in the cement slurry is 1:1.

[0040] The grouting holes of the top grouting valve of the second steel pipe are covered with two layers of elastic sealing rubber rings, and the grouting holes of the two groups of grouting valves at the bottom and the grouting holes of the grouting valve at the bottom of the first steel pipe are covered with a layer of elastic sealing rubber ring. The grouting bearing pressure of the single-layer elastic sealing rubber ring is 0.15MPa, and the grouting bearing pressure of the double-layer elastic sealing rubber ring is 0.3MPa; in step ⑤, the water injection pressure is less than 0.3MPa, and in step ⑥, the water injection pressure is greater than 0.3MPa.

[0041] In this embodiment, the grouting pressure in steps ③ and ④ is less than 0.3 MPa, but greater than 0.15 MPa. Thus, when the cement slurry is injected into the second steel pipe, the cement slurry will completely fill the second steel pipe. Since the grouting pressure of the single-layer elastic sealing rubber ring is 0.15 MPa, the cement slurry will overflow from the grouting holes of the two sets of grouting valves below, breaking through the seal of the single-layer elastic sealing rubber ring below. In this way, the cement slurry will be sent from the bottom of the second steel pipe into the soil layer, mixed with water glass, and quickly set. In step ⑦, the cement slurry is directly sent from the top grouting valve, breaking through the double-layer elastic sealing rubber ring, and the cement slurry enters the loose and porous soil and soil layer to fill and reinforce it. Among them, the use of double-layer elastic sealing rubber rings and single-layer elastic sealing rubber rings can distinguish different positions, prevent the subsequent cement slurry and water glass from mixing, and play a role in filling and reinforcing. Moreover, the same set of equipment can be used to achieve sealing and processing, which is efficient and cost-effective.

[0042] See also Figures 1 to 4 As shown, the grouting valve is a hollow structure with openings at both ends. A through groove 7 is provided in the middle of the grouting valve, and both ends of the through groove are respectively connected to the two ends of the grouting valve; and external threads are respectively provided on the outer surfaces of both ends of the grouting valve.

[0043] A plurality of annular grooves 8 are provided on the outer surface of the grouting valve from top to bottom. The grouting holes are provided on the outer walls of the annular grooves, and the inner ends of the grouting holes are connected to the through grooves. The elastic sealing rubber ring is provided in the annular grooves.

[0044] The bottom of the grouting valve at the bottom of the first steel pipe and the second steel pipe is screwed with a plug 9. The plug is screwed to the external thread at the bottom of the grouting valve.

[0045] The first and second steel pipes are flush with each other at the top. The second steel pipe comprises an upper steel pipe 10, a middle steel pipe 11, and a lower steel pipe 12. The lower steel pipe connects the two lower sets of grouting valves, the middle steel pipe connects the top and middle grouting valves, and the bottom of the upper steel pipe connects the top grouting valve. The second steel pipe adopts a multi-section structure to facilitate the installation of multiple sets of grouting valves. The lower, middle, and upper steel pipes are screwed to the corresponding external threads of the grouting valves.

[0046] The first steel pipe is used for injecting water glass, the second steel pipe is used for injecting cement slurry, and the bottom of the bottom grouting valve is sealed with a plug. This prevents the slurry from being sent out from the bottom of the grouting valve and can only break through the corresponding elastic sealing rubber ring and overflow from the grouting hole. In addition, the external thread on the through groove is used to connect the plug and the steel pipe. The annular groove facilitates the installation of the elastic sealing rubber ring. In this way, when the steel pipe and grouting valve are pressed into the soil layer, the elastic sealing rubber ring will be protected by the annular groove to prevent it from escaping from the grouting hole, thus protecting the grouting hole. At the same time, it also acts as a one-way valve, so that the slurry can only flow out of the soil layer after being pressurized from the inside of the grouting valve. The soil and other materials in the soil layer cannot enter the grouting hole from the edge of the elastic sealing rubber ring, thus achieving a one-way conveying effect and also a protective function.

[0047] The wall thickness of the elastic sealing rubber ring is 2 mm. This allows it to withstand a deformation pressure of 0.15 MPa, and the double-layer elastic sealing rubber ring can withstand a deformation pressure of 0.3 MPa. That is, when the pressure inside the steel pipe is less than 0.15 MPa, the slurry inside cannot break through the elastic strength of the single-layer elastic sealing rubber ring, and the grouting hole cannot be slurried. When the pressure exceeds 0.15 MPa, the pressure exerted by the grouting hole on the elastic sealing rubber ring will cause it to deform, so that the slurry can flow out of the grouting hole and out of the gap between the elastic sealing rubber ring and the grouting valve, completing the grouting work.

[0048] Among them, multiple groups of connecting components are arranged at intervals from top to bottom, and the connecting components include a first ring 13 and a second ring 14 that are connected to each other, the middle part of the first steel pipe is inserted into the first ring, the middle part of the second steel pipe is inserted into the second ring, and the first steel pipe is welded to the second ring, and the second steel pipe is welded to the second ring.

[0049] Among them, the outer surface of the first ring is welded and fixed to the outer surface of the second ring, or the first ring and the second ring are an integrally formed structure, which is used to connect the first steel pipe with the second steel pipe so that the two sets of steel pipes are parallel, so that the cement slurry can be smoothly mixed with the water glass when it is delivered.

Claims

1. A deep foundation pit combined grouting and plugging process, comprising the following steps: ① During the process of assembling the grouting pipe with the first steel pipe and the second steel pipe respectively, the first steel pipe and the second steel pipe are connected by using a connecting assembly; The first steel pipe and the second steel pipe are respectively connected via multiple groups of the connecting components. A grouting valve is provided at the bottom of the first steel pipe, and three groups of grouting valves are provided on the second steel pipe. The three groups of grouting valves on the second steel pipe are spaced apart from each other from bottom to top, and one group of grouting valves is provided at the bottom of the second steel pipe. The vertical spacing between the grouting valve of the first steel pipe and the grouting valve at the bottom of the second steel pipe is greater than or equal to 1 meter; the vertical spacing between adjacent grouting valves on the second steel pipe is greater than or equal to 1.5 meters. The outer surface of the grouting valve is provided with multiple groups of grouting holes, and each group of grouting holes is covered with a group of elastic sealing rubber rings; and each group of grouting holes of the grouting valve at the top of the second steel pipe is covered with two groups of elastic sealing rubber rings; ②Insert the first and second steel pipes into the leaking deep foundation pit until they reach the corresponding depth; ③Inject water glass into the first steel pipe at a flow rate of 30L / min. The water glass flows out from the grouting holes of the grouting valve at the bottom of the first steel pipe and continues for 10 minutes. Then, while the first steel pipe continues to inject water glass, the second steel pipe injects cement slurry. The cement slurry flows out from the grouting holes of the two groups of grouting valves at the bottom of the second steel pipe. The injection flow rate of cement slurry is the same as that of water glass. Observe the leakage points inside the deep foundation pit until the leakage stops. ④ After the leaking point stops leaking, continue to inject water glass and cement slurry at the same flow rate for 30 minutes, and then stop injecting water glass and cement slurry; ⑤ After the injection of water glass and cement slurry stops for 10 minutes, inject clean water into the second steel pipe to open the second steel pipe filled with cement slurry; ⑥ After the second steel pipe is opened, increase the water injection pressure and use clean water to open the grouting hole of the top grouting pipe, so that the clean water flows out from the grouting hole of the top grouting valve, and continue for 1 minute; ⑦ Stop injecting clean water into the second steel pipe, and then inject cement slurry into the second steel pipe. The cement content in the injected cement slurry is 10t~50t. Use the cement slurry to reinforce the upper loose and hollow soil.

2. The deep foundation pit combined grouting and plugging process according to claim 1, characterized in that: The ratio of water to cement in cement paste is 1:

1.

3. The deep foundation pit combined grouting and plugging process according to claim 1, characterized in that: The slurry discharge bearing pressure of the single-layer elastic sealing rubber ring is 0.15MPa, and the slurry discharge bearing pressure of the double-layer elastic sealing rubber ring is 0.3MPa; in step ⑤, the water injection pressure is less than 0.3MPa, and in step ⑥, the water injection pressure is greater than 0.3MPa.

4. The deep foundation pit combined grouting and plugging process according to claim 1, characterized in that: The grouting valve is a hollow structure with openings at both ends. A through groove is provided in the middle of the grouting valve, and both ends of the through groove are respectively connected to the two ends of the grouting valve; and external threads are respectively provided on the outer surfaces of the two ends of the grouting valve.

5. The deep foundation pit combined grouting and plugging process according to claim 4, characterized in that: A plurality of annular grooves are provided on the outer surface of the grouting valve from top to bottom, the grouting holes are provided on the outer walls of the annular grooves, and the inner ends of the grouting holes are connected to the through grooves, and the elastic sealing rubber ring is provided in the annular grooves.

6. The deep foundation pit combined grouting and plugging process according to claim 1, characterized in that: The bottom of the grouting valve at the bottom of the first steel pipe and the second steel pipe is screwed with a plug.

7. The deep foundation pit combined grouting and plugging process according to claim 1, characterized in that: The first steel pipe is arranged flush with the top of the second steel pipe. The second steel pipe includes an upper steel pipe, a middle steel pipe and a lower steel pipe. The lower steel pipe connects the two groups of grouting valves below. The middle steel pipe connects the top grouting valve with the middle grouting valve. The bottom of the upper steel pipe is connected to the top grouting valve.

8. The deep foundation pit combined grouting and plugging process according to claim 1, characterized in that: The wall thickness of the elastic sealing rubber ring is 2 mm.

9. The deep foundation pit combined grouting and plugging process according to claim 1, characterized in that: Multiple groups of connecting components are arranged at intervals from top to bottom, and the connecting components include a first ring and a second ring that are connected to each other. The middle part of the first steel pipe is inserted into the first ring, and the middle part of the second steel pipe is inserted into the second ring. The first steel pipe is welded to the second ring, and the second steel pipe is welded to the second ring.

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