Front support grouting steel pipe precise grouting device based on double-air-bag positioning and construction method

Abstract

The invention relates to a front support grouting steel pipe precise grouting device based on double-air-bag positioning and a construction method. The device comprises a grouting steel pipe, a first air bag, a second air bag, a grouting pipe and an air supply device. A grouting section is arranged on the grouting steel pipe, and a plurality of first grouting holes are formed in the grouting section; the air supply device is provided with air supply pipes connected to the first air bag and the second air bag correspondingly, the first air bag is used for sealing the bottom of the corresponding grouting section in the grouting steel pipe after being inflated, the second air bag is an annular air bag, a through hole is formed in the middle, and the second air bag is used for sealing the top of the corresponding grouting section of the grouting steel pipe after being inflated. When the grouting pipe is used, the grouting pipe penetrates through the through hole to stretch into the grouting section of the grouting steel pipe and is used for grouting the grouting section. Through the synergistic effect of the first air bag and the second air bag, sealing isolation of the upper end and the lower end of the grouting section is achieved, it is ensured that grout is accurately injected into a target area, karst caves and silty clay are effectively avoided, the positioning precision of the grouting section is improved, and the grout utilization rate is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of construction engineering, and particularly to a precise grouting device and construction method for a front support grouting steel pipe based on double-airbag positioning. Background Technique

[0002] In traditional grouting processes, in complex geological conditions such as karst cave development areas, silt layers, and limestone where karst caves and loose structures are likely to occur, the positioning accuracy of the grouting section is insufficient, easily leading to the infiltration of grout into karst caves or non-target areas, resulting in material waste and construction risks. Especially in limestone formations, the distribution of karst caves is complex, and it is difficult for existing technologies to accurately isolate the grouting section. Summary of the Invention

[0003] In order to solve the deficiencies existing in the above-mentioned prior art, the present invention provides a precise grouting device for a front support grouting steel pipe based on double-airbag positioning, including a grouting steel pipe, a first airbag, a second airbag, a grouting pipe, and a gas supply device; a grouting section is provided on the grouting steel pipe, and a number of first grouting holes are provided at the grouting section; the gas supply device is provided with gas supply pipes respectively connected to the first airbag and the second airbag, the first airbag is used to seal the bottom of the corresponding grouting section inside the grouting steel pipe after inflation, the second airbag is an annular airbag with a through hole in the middle, and the second airbag is used to seal the top of the corresponding grouting section of the grouting steel pipe after inflation; the grouting pipe passes through the through hole and extends into the grouting section of the grouting steel pipe during use for grouting the grouting section.

[0004] During use, the first airbag is inflated to seal the bottom of the grouting section. After the grouting pipe passes through the through hole of the second airbag, the second airbag is inflated to seal the top of the grouting section, so that a grouting interval is formed in the preset grouting section, thereby accurately grouting the grouting section.

[0005] Further, the second airbag includes a number of airbag bags, and each airbag bag is connected; in the non-inflated state, each airbag bag is stacked, and in the inflated state, the edges of each airbag bag are closely attached to the inner wall of the grouting steel pipe. The second airbag adopts a multi-layer folding design, which can make the sealing effect better.

[0006] Further, the first airbag is a spherical airbag, and the first airbag cannot be recovered after grouting. Using a spherical airbag can reduce costs. The first airbag and the second airbag are made of elastic rubber with an expansion rate of not less than 200%.

[0007] Further, a compressive fiber layer is provided inside the first airbag and the second airbag to increase strength.

[0008] Further, a rubber skirt for connecting the grouting pipe is provided at the top of the second airbag, which is convenient for connecting the second airbag and the grouting pipe, making the process of laying the grouting pipe and the second airbag more convenient.

[0009] Further, the grouting pipe is a cylindrical hollow pipe, and a number of second grouting holes are evenly arranged on the pipe wall. The upper end of the grouting pipe is connected to a grouting pump.

[0010] Further, an outer wall of the grouting steel pipe in the grouting section is provided with a covering bladder, and upper and lower ends of the covering bladder are hermetically connected to the outer wall of the grouting steel pipe.

[0011] The present invention also provides a precise grouting construction method for a front support grouting steel pipe based on double - air - bag positioning, which is used for the device as described above, and includes the following steps: S1. Place the grouting steel pipe at a predetermined position, connect the first air - bag to an air - supply device through an air - supply pipe, and place the first air - bag at the bottom of the grouting section. Inflate it to 0.3 - 0.5 MPa to make the first air - bag expand and form a seal with the inner wall of the grouting steel pipe.

[0012] S2. Pass the grouting pipe through the through - hole of the second air - bag, place the second air - bag at the top of the grouting section, and inflate it to 0.3 - 0.5 MPa to make the second air - bag expand and form a seal with the inner wall of the grouting steel pipe and the outer wall of the grouting pipe, thus forming a grouting interval.

[0013] S3. Inject grout into the grouting interval through the grouting pipe, and stop grouting when the grouting pressure reaches 1.5 - 2.0 MPa.

[0014] S4. After grouting is completed, let it stand for 30 - 60 min, then release the air pressure of the air - bags, recover the second air - bag and clean the pipeline. At least the second air - bag and its air pipe can be completely recovered, which can reduce the construction cost.

[0015] Further, a rubber skirt is provided at the top of the second air - bag; in S2, use a clamp to fixedly connect the rubber skirt to the outer wall of the grouting pipe to connect the second air - bag and the grouting pipe, making the process of arranging the grouting pipe and the second air - bag more convenient.

[0016] Further, in S3, it also includes that during the grouting process, monitor the grouting pressure, and stop grouting when the grouting pressure drops to a first pressure threshold within a first time threshold to prevent the grout from infiltrating into the karst cave and causing waste.

[0017] Further, the first time threshold is taken from 0 - 2.0 s, and the first pressure threshold is taken from 0 - 1.0 MPa.

[0018] Through the synergistic effect of the first air - bag and the second air - bag, the present invention realizes the upper and lower end sealing and isolation of the grouting section, ensures that the grout is accurately injected into the target area, effectively avoids the karst cave and loose soil layer, reduces the risk of geological disasters, improves the positioning accuracy of the grouting section, and improves the utilization rate of the grout. The present invention can also be partially reused to save the construction cost. Description of the Drawings

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0020] Figure 1 is a schematic diagram of the use of the device of the present invention; Figure 2 is a schematic diagram of the second airbag of the present invention; Figure 3 is a schematic diagram of the covering bag of the present invention; Figure 4 is a schematic diagram of grouting in the method of the present invention; In the figure: 1. Second airbag; 2. First airbag; 3. Clamp; 4. Grouting pipe; 5. Air supply device; 6. Rubber skirt; 7. Air supply pipe; 8. Slurry; 9. Bag; 10. Covering bag; 11. Limestone layer; 12. Mucky soil layer; 13. Silty clay layer; 14. Karst cave; 15. Grouting steel pipe. Detailed implementation manners

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0022] Embodiment 1:

[0023] Refer to Figure 1 , the precise grouting device for the front support grouting steel pipe based on double airbag positioning in this embodiment includes a grouting steel pipe 15, a first airbag 2, a second airbag 1, a grouting pipe 4, and an air supply device 5. A grouting section is provided on the grouting steel pipe 15, and a number of first grouting holes are provided at the grouting section. The air supply device 5 is provided with air supply pipes 7 respectively connected to the first airbag 2 and the second airbag 1. The first airbag 2 is used to seal the bottom of the corresponding grouting section in the grouting steel pipe 15 after inflation. The second airbag 1 is an annular airbag with a through hole in the middle. The second airbag 1 is used to seal the top of the corresponding grouting section of the grouting pipe 4 after inflation. When in use, the grouting pipe 4 passes through the through hole and extends into the grouting section of the grouting steel pipe 15 for grouting the grouting section.

[0024] Refer to Figure 2, preferably, the second airbag 1 includes a plurality of air pockets 9 which are communicated with each other; in the non-inflated state, the air pockets 9 are stacked, and in the inflated state, the edges of the air pockets 9 are closely attached to the inner wall of the grouting steel pipe 15. The second airbag 1 adopts a multi-layer folding design, which can make the sealing effect better. The first airbag 2 is a spherical airbag, and the first airbag 2 cannot be recovered after grouting. Adopting a spherical airbag can reduce costs. The first airbag 2 and the second airbag 1 are made of elastic rubber with an expansion rate of not less than 200%, and a compressive fiber layer is provided inside the first airbag 2 and the second airbag 1 to increase strength.

[0025] Preferably, a rubber skirt 6 for connecting the grouting pipe 4 is provided at the top of the second airbag 1, which is convenient for connecting the second airbag 1 and the grouting pipe 4, making the process of laying the grouting pipe 4 and the second airbag 1 more convenient and facilitating the precise laying of the second airbag 1.

[0026] Preferably, the grouting pipe 4 is a cylindrical hollow pipe, and a plurality of second grouting holes are uniformly formed in the pipe wall. The upper end of the grouting pipe 4 is connected to a grouting pump.

[0027] See Figure 3 , preferably, a covering bag 10 is provided on the outer wall of the grouting steel pipe 15 in the grouting section. The upper end and the lower end of the covering bag 10 are hermetically connected to the outer wall of the grouting steel pipe 15. For example, the covering bag 10 is hermetically connected to the grouting steel pipe 15 by using a hoop. By providing the covering bag 10, the flow of the slurry during grouting is restricted, so that the slurry can only exist around the grouting section, which can effectively prevent slurry waste.

[0028] In this embodiment, taking the limestone layer 11, the silt layer 12 and the silty clay layer 13 from bottom to top as an example, where there is a karst cave 14 in the limestone layer 11, and the silt layer 12 needs to be grouted and reinforced during construction. When this embodiment is used, the grouting steel pipe 15 is fabricated, and the covering bag 10 is fixed on the outer wall of its grouting section. Then, the grouting section is placed in the silt layer 12, and the first airbag 2 is inflated to seal the bottom of the grouting section. After the grouting pipe 4 passes through the through hole of the second airbag 1, the rubber skirt 6 and the grouting pipe 4 are connected by a clamp 3, so that the second airbag 1 is fixed on the grouting pipe 4. The second airbag 1 is inflated to seal the top of the grouting section, so that a grouting interval is formed in the preset grouting section, and thus precise grouting of the grouting section is carried out.

[0029] Embodiment 2:

[0030] See Figure 4 , the precise grouting construction method of the front support grouting steel pipe based on double airbag positioning in this embodiment is used for the device in the above embodiment, and includes the following steps: S1. Place the grouting steel pipe 15 at a predetermined position, connect the first airbag 2 to the air supply device 5 through the air supply pipe 7, and place the first airbag 2 at the bottom of the grouting section, and inflate it to 0.3 - 0.5 MPa so that the first airbag 2 expands to form a seal with the inner wall of the grouting steel pipe 15.

[0031] S2. Pass the grouting pipe 4 through the through-hole of the second airbag 1, place the second airbag 1 at the top of the grouting section, inflate it to 0.3 - 0.5 MPa to make the second airbag 1 expand and form a seal with the inner wall of the grouting steel pipe 15 and the outer wall of the grouting pipe 4, thus forming a grouting interval. For the solution where the second airbag 1 is provided with a rubber skirt 6, use a clamp 3 to fixedly connect the rubber skirt 6 to the outer wall of the grouting pipe 4, and fixedly connect the second airbag 1 and the grouting pipe 4, making the process of laying the grouting pipe 4 and the second airbag 1 more convenient.

[0032] S3. Inject the grout 8 into the grouting interval through the grouting pipe 4, and control the grouting pressure to be 1.5 - 2.0 MPa.

[0033] S4. After the grouting is completed, let it stand for 30 - 60 min, then release the air pressure of the airbag, recover the second airbag and clean the pipeline. At least the second airbag 1 and its air pipe can be recovered completely, which can reduce the construction cost.

[0034] Preferably, for the scenario where it is not convenient to set the covering airbag 10, in order to prevent waste of grout, in S3, monitor the grouting pressure, and stop grouting when the grouting pressure drops to the first pressure threshold within the first time threshold. When the grouting pressure drops to the first pressure threshold within the first time threshold, it can be inferred that the grout 8 flows into the karst cave 14 or other soft areas. At this time, if the grouting pressure is maintained and continuous grouting is required, it is easy to cause waste of the grout 8. Preferably in this embodiment, the first time threshold is taken from 0 - 2.0 s, and the first pressure threshold is taken from 0 - 1.0 MPa.

[0035] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and its equivalent technologies, the present invention also intends to include these changes and modifications.

Claims

1. A precise grouting device for a front support grouting steel pipe based on double airbag positioning, characterized in that It includes a grouting steel pipe, a first airbag, a second airbag, a grouting pipe, and a gas supply device; a grouting section is provided on the grouting steel pipe, and a number of first grouting holes are provided at the grouting section; the gas supply device is provided with gas supply pipes respectively connected to the first airbag and the second airbag. The first airbag is used to seal the bottom corresponding to the grouting section inside the grouting steel pipe after inflation. The second airbag is an annular airbag with a through hole in the middle. The second airbag is used to seal the top corresponding to the grouting section of the grouting steel pipe after inflation; when in use, the grouting pipe passes through the through hole and extends into the grouting section of the grouting steel pipe for grouting into the grouting section.

2. The precise grouting device for the front support grouting steel pipe based on double-airbag positioning according to claim 1, wherein The second airbag includes a number of air pockets, and each air pocket is connected; in the non-inflated state, each air pocket is stacked, and in the inflated state, the edges of each air pocket are closely attached to the inner wall of the grouting steel pipe.

3. The precise grouting device for the front support grouting steel pipe based on double airbag positioning according to claim 2, characterized in that, The first airbag is a spherical airbag; the first airbag and the second airbag are made of elastic rubber with an expansion rate of not less than 200%; a compressive fiber layer is provided inside the first airbag and the second airbag.

4. The precise grouting device for the front strut grouting steel pipe based on double airbag positioning according to claim 2, wherein, A rubber skirt for connecting the grouting pipe is provided at the top of the second airbag.

5. The precise grouting device for front strut grouting steel pipes based on double-airbag positioning according to claim 1, wherein, The grouting pipe is a cylindrical hollow pipe, and a number of second grouting holes are evenly opened on the pipe wall. The upper end of the grouting pipe is connected to a grouting pump.

6. The precise grouting device for the front support grouting steel pipe based on double-airbag positioning according to claim 1, characterized in that A covering bag is provided on the outer wall of the grouting steel pipe at the grouting section, and the upper end and the lower end of the covering bag are hermetically connected to the outer wall of the grouting steel pipe.

7. A precise grouting construction method for a front support grouting steel pipe based on double airbag positioning, characterized in that, For the device as described in claim 1, it includes the following steps: S1. Place the grouting steel pipe at a predetermined position, connect the first airbag to the gas supply device through the gas supply pipe, and place the first airbag at the bottom of the grouting section, inflate it to 0.3 - 0.5 MPa to make the first airbag expand and form a seal with the inner wall of the grouting steel pipe; S2. Pass the grouting pipe through the through hole of the second airbag, place the second airbag at the top of the grouting section, inflate it to 0.3 - 0.5 MPa to make the second airbag expand and form a seal with the inner wall of the grouting steel pipe and the outer wall of the grouting pipe, forming a grouting interval; S3. Inject slurry into the grouting interval through the grouting pipe, and stop grouting when the grouting pressure reaches 1.5 - 2.0 MPa; S4. After grouting is completed, let it stand for 30 - 60 min, then release the air pressure of the airbag, recover the second airbag and clean the pipeline.

8. The precise grouting construction method of the front support grouting steel pipe based on double airbag positioning according to claim 7, characterized in that, A rubber skirt is provided at the top of the second airbag; in S2, use a clamp to fixedly connect the rubber skirt to the outer wall of the grouting pipe.

9. The precise grouting construction method of the front support grouting steel pipe based on double-airbag positioning according to claim 7, characterized in that, In S3, it also includes that during the grouting process, monitor the grouting pressure, and stop grouting when the grouting pressure drops to the first pressure threshold within the first time threshold.

10. The precise grouting construction method of the front support grouting steel pipe based on double airbag positioning according to claim 9, characterized in that, The first time threshold is taken from 0 - 2.0 s, and the first pressure threshold is taken from 0 - 1.0 MPa.

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