Testing device for measuring seepage-proofing effect of sequential hole grouting

Abstract

The utility model provides a testing device for measuring the grouting seepage-proofing effect of a sequential hole. The testing device comprises a grouting system, a model box and a water pressing testing system. Grouting holes are formed in the side surface, close to the bottom, of the grouting barrel; a grouting pipeline is arranged between the grouting opening and the grouting barrel, and a row of drainage holes are formed in the bottom of the plane side of the model box; the water injection pipe is connected with the grouting hole channel, and a hole packer is arranged in a gap between the water injection pipe and the grouting hole channel. According to the device, sequence hole grouting can be simulated by controlling the movement of the grouting pipe, the flowing, filling, displacement and solidification processes of grout in an underground soil layer can be observed in real time, and the permeability coefficient of a grouting body can be measured through a water pressing test, so that the grouting process is quantitatively observed, and the grouting effect is evaluated; according to the invention, the test simulation of construction conditions among different sequential holes can be carried out, key construction control factors such as cement slurry ratio, grouting process, grouting pressure and the like during grouting construction of different sequential holes can be determined, and the permeability of a grouting reinforcement body can be quantitatively evaluated, so that the aim of measuring the grouting seepage-proofing effect of the sequential holes can be achieved.

Description

Technical Field

[0001] The utility model relates to the field of tunnels and underground engineering, in particular to a test device for measuring the anti-seepage effect of sequential hole grouting. Background Art

[0002] Gravel strata are widely distributed across my country, and are increasingly being used in underground projects, with increasing demands for their utilization. However, due to the complexity and variability of gravel structures, their large pores provide a favorable conduit for groundwater, resulting in large water inrush rates and poor impermeability. This makes them prone to water inrush, leading to unstable structures and frequent accidents such as the collapse of bulk materials and large-scale landslides. Currently, grouting is commonly used to improve the impermeability of gravel layers to meet project requirements.

[0003] The grouting anti-seepage method is to inject cement-based slurry from the bottom up into the cracks, pores, voids and confined aquifers of the soil through a conduit or other device. After diffusion, hardening and solidification, the slurry fully fills the soil voids to reduce the permeability of the soil and form a cemented body of a certain thickness. At this time, the strength and stability of the soil are greatly enhanced, thereby achieving the goals of water blocking, reinforcement and anti-seepage. During the multi-porous sequential grouting process, engineering problems such as weakened reinforcement and unsatisfactory anti-seepage effect are prone to occur. During the grouting construction at the project site, the cement slurry ratio, grouting process, grouting pressure and other factors are key construction control factors, which directly determine the grouting effect such as the slurry diffusion range and the permeability of the grouting reinforcement.

[0004] Grouting holes are generally arranged in multiple rows with intervals. Grouting is not carried out sequentially along the direction of the drilling arrangement, but rather in intervals, i.e., skip-hole grouting. The odd-numbered holes are grouted first as the first-order holes, and then the remaining even-numbered holes are grouted as the second-order holes. This is called sequential hole grouting in engineering. Obviously, the first-order grouting in the sequential hole grouting process will form a "slurry curtain" around the grouting holes, affecting the diffusion of the slurry in the subsequent grouting holes, reducing the slurry diffusion, filling, displacement, and solidification effects of the subsequent grouting holes, and thus affecting the ultimate anti-seepage effect of the entire formation. Grouting is a complex system engineering. Because grouting projects are concealed projects, the diffusion process of the grouting material in the formation is concealed, and the diffusion pattern of the slurry is extremely complex. In order to determine the grouting construction parameters, simulated grouting experiments are required. Utility Model Content

[0005] The main purpose of the utility model is to provide a test device for measuring the anti-seepage effect of sequential hole grouting, hoping to effectively solve the problems in the background technology.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] A test device for measuring the anti-seepage effect of sequential hole grouting, comprising a grouting system, a model box, and a water pressure test system;

[0008] The grouting system includes an air compressor, an air pressure regulating valve, a grouting pipe, and a grouting bucket. The air compressor outlet is provided with an air pressure regulating valve, the top of the grouting bucket is provided with a first top plate, the first top plate is provided with a grouting valve, a grouting pipe is provided between the air pressure regulating valve and the grouting valve, and a grouting hole is provided on the side of the grouting bucket near the bottom;

[0009] The model box consists of a semi-cylinder with an open top and a second top plate. A grouting channel is provided at the center of the semi-circle of the model box. Grouting ports are provided at two trisection points on the grouting channel respectively. A grouting pipe is provided between the grouting port and the grouting bucket. A plurality of shower-shaped small holes are provided at the upper and lower trisections of the grouting channel. The second top plate is provided on the top of the semi-cylinder. A row of drainage holes is provided at the bottom of the flat side of the model box.

[0010] The water pressure test system is composed of a water supply pipeline, a water injection pump, a water injection meter, a one-way valve, a high-pressure hose, a valve, a second flow meter, a pressure gauge, and a water injection pipe in sequence. The water injection pipe is connected to the grouting channel, and a sealer is provided in the gap between the water injection pipe and the grouting channel.

[0011] While adopting the above technical solutions, the present invention may also adopt or combine the following technical solutions:

[0012] As an optimal technical solution of the present invention: the grouting pipe in the grouting system is a reinforced pumping pipe with a pressure resistance of more than 10 MPa.

[0013] As an optimal technical solution of the present invention: the plane of the model box is made of transparent material.

[0014] As a preferred technical solution of the present invention: a pressure gauge and a first flow meter are provided on the grouting pipe between the grouting port and the grouting bucket.

[0015] As a preferred technical solution of the present invention: the pressure gauge and the first flow meter are connected to a computer.

[0016] As an optimal technical solution of the present invention: a camera is provided on the outside of the plane side of the model box.

[0017] As a preferred technical solution of the present invention: the first top plate is connected to the grouting bucket by fine steel screws.

[0018] As a preferred technical solution of the present invention: the second top plates are connected to the model box via fine steel screws.

[0019] As an optimal technical solution of the present invention: a rubber pad is provided between the model box plates, and a rigid curing sealant is provided at the connection.

[0020] As an optimal technical solution of the present invention: the high-pressure hose in the water pressure test system is a transparent steel wire spiral reinforced hose with a pressure resistance of more than 4MPa.

[0021] The utility model provides a test device for measuring the anti-seepage effect of sequential hole grouting, which has the following beneficial effects: the device can simulate the sequential hole grouting by controlling the movement of the grouting pipe, can observe the flow, filling, displacement and solidification process of the slurry in the underground soil layer in real time, and can perform a water pressure test to measure the permeability coefficient of the grouting body, thereby quantitatively observing the grouting process and evaluating the grouting effect; the test simulation of the construction conditions between different sequential holes can be performed, and key construction control factors such as the cement slurry ratio, grouting process, grouting pressure, etc. during the grouting construction of different sequential holes can be determined, and the permeability of the grouting reinforcement body can be quantitatively evaluated, thereby achieving the purpose of measuring the anti-seepage effect of the sequential hole grouting. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of a test device for measuring the anti-seepage effect of sequential hole grouting provided by the present invention;

[0023] Figure 2 It is the main view of the model box;

[0024] Figure 3 is a top view of the model box;

[0025] Figure 4 is a schematic diagram of the grouting system;

[0026] Figure 5 It is a schematic diagram of the water pressure test system;

[0027] Figure 6 is a schematic diagram of an electric mixer;

[0028] In the figure: 1-air compressor; 2-air pressure regulating valve; 3-grouting bucket; 4-pressure gauge; 5-first flow meter; 6-computer; 7-camera; 8-model box; 9-grouting channel; 10-bolt hole; 11-grouting port; 12-drain hole; 13-electric mixer; 14-grouting valve; 15-grouting pipe; 16-fine steel screw; 17-grouting hole; 18-water injection pipe; 19-hole sealer; 20-pressure gauge; 21-second flow meter; 22-valve; 23-high-pressure hose; 24-check valve; 25-water injection meter; 26-water injection pump; 27-water supply pipeline. DETAILED DESCRIPTION

[0029] The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

[0030] like Figure 1-6As shown, a test device for measuring the anti-seepage effect of sequential hole grouting includes a grouting system, a model box 8, and a water pressure test system;

[0031] The grouting system includes an air compressor 1, an air pressure regulating valve 2, a grouting pipe 15, and a grouting bucket 3. The air compressor 1 is provided with an air pressure regulating valve 2 at its outlet. The grouting bucket 3 is provided with a first top plate on top, and a grouting valve 14 is provided on the first top plate. A grouting pipe 15 is provided between the air pressure regulating valve 2 and the grouting valve 14. A grouting hole 17 is provided on the side of the grouting bucket 3 near the bottom.

[0032] The model box 8 is composed of a semi-cylinder with an open top and a second top plate. A grouting channel 9 is provided at the center of the semicircle of the model box 8. Grouting ports 11 are provided at two trisection points on the grouting channel 9. A grouting pipe 15 is provided between the grouting port 11 and the grouting bucket 3. A plurality of small shower-like holes are provided at the upper and lower trisections of the grouting channel 9. The second top plate is provided at the top of the semi-cylinder. A row of drainage holes with an aperture of 20 mm is provided at the bottom of the plane side of the model box 8. The two grouting ports 11 can be regarded as the first sequence hole (lower grouting port) and the second sequence hole grouting for on-site sequential hole grouting. For the sequence hole (upper grouting port), first, the grouting pipe 15 (elastic and can be pressurized to the side wall) is placed at the lower grouting port 11, that is, the position of the first sequence hole. Then, the grouting pipe 15 is pressurized to block the hole so that the slurry can only be injected from the first sequence hole. When the lowest liquid level of the cement slurry is higher than that of the first sequence hole, the grouting is stopped. Then, the grouting pipe is pulled up and moved to the upper grouting port 11, that is, the second sequence hole. The above process is repeated, and the effect of the "slurry curtain" formed around the grouting hole by the first sequence grouting on the diffusion of the slurry in the subsequent sequence grouting holes can be observed.

[0033] The water pressure test system is composed of a water supply pipeline 27, a water injection pump 26, a water injection meter 25, a one-way valve 24, a high-pressure hose 23, a valve 22, a second flow meter 21, a pressure gauge 20, and a water injection pipe 18. The water injection pipe 18 is connected to the grouting channel 9. A sealer 19 is provided in the gap between the water injection pipe 18 and the grouting channel 9. The second flow meter 21 records flow changes every 5 minutes. The pressure gauge 20 is used to monitor the water injection pressure during the test.

[0034] The grouting pipe 15 in the grouting system is a reinforced pumping pipe with a pressure resistance of more than 10 MPa.

[0035] The plane of the model box 8 is a transparent acrylic plate, which can facilitate the observation of the slurry diffusion movement. The main body of the model box 8 is a 750mm semi-cylinder with a wall thickness of 20mm.

[0036] A pressure gauge 4 and a first flow meter 5 are provided on the grouting pipe 15 between the grouting port 11 and the grouting barrel 3 .

[0037] The pressure meter 4 and the first flow meter 5 are connected to the computer 6 .

[0038] A camera 9 is provided on the outside of the plane side of the model box 8. The camera 9 is used for PIV (particle image velocimetry) technology and can observe the slurry diffusion, displacement and solidification process in real time.

[0039] The first top plate is connected to the grouting bucket 3 via fine steel screws 16 .

[0040] The second top plate is connected to the model box 8 by fine steel screws 16. The size of the second top plate is a semicircle with a radius of 830mm, and a bolt hole 10 with a radius of 20mm is opened 30mm inward from the edge, and the spacing between the holes is 75mm.

[0041] Rubber pads are provided between the plates of the model box 8, and rigid curing sealant is provided at the joints to ensure the airtightness of the model box 8.

[0042] The high-pressure hose 23 in the water pressure test system is a transparent steel wire spiral reinforced hose with a pressure resistance of more than 4 MPa.

[0043] Specifically, the test device for measuring the anti-seepage effect of sequential hole grouting is implemented in the following manner:

[0044] S1: The soil samples brought back from the site will be screened to select sand and gravel with a particle size of 10-50 mm. An acrylic plate will be used as a second top plate at the open end of the model box 8, and a layer of rubber pad will be placed. After the screened sand and gravel soil samples are loaded into the model box, the second top plate will be covered on the open end of the model box 8 to seal it. Finally, the stainless steel screws 16 will be tightened on the bolt holes 10 to fix it. The rubber pad will be sandwiched between the plates of the model box 8 to increase the waterproof sealing performance. Rigid curing sealant will be applied to the joints of the plates inside the model box 8 to ensure that the injected water and slurry will not overflow from the joints.

[0045] S2: Put a certain proportion of lime and water into the grouting bucket 3, stir the cement slurry thoroughly and evenly with an electric mixer 13, and then seal the grouting bucket 3 and the mold box 8 in the same way;

[0046] S3: Prepare the grouting system. The grouting system can be connected to the grouting channel 9 through the grouting pipe 15. The prepared slurry is injected into different grouting ports 11 on the grouting channel 9 of the model box 8 in batches. First, the grouting pipe 15 is placed at the grouting port 11 at the bottom. Then, pressurize the grouting pipe 15 to expand the slurry to the side wall and start grouting. The time point for stopping injection at the grouting port 11 at the bottom is when the lowest liquid level of the cement slurry is above the grouting port 11, and the grouting pipe 15 starts to relieve pressure. Then, the grouting pipe 15 is pulled up and moved to the grouting port 11 above, and the above process is repeated. When the entire model box 8 is filled with cement slurry, the grouting is stopped, and the effect of the "slurry curtain" formed around the grouting hole by the previous grouting on the diffusion of the slurry in the subsequent grouting hole can be observed; during the grouting, the pressure gauge 4 and the first flow meter 5 are connected to the computer 6 to record the grouting construction parameters in real time. At the same time, the PIV technology is used to record the changes in the slurry parameters such as pressure over time and the changes in the diffusion range of the slurry;

[0047] S4: After the grouting is completed, the agglomerate is cured for 3d, 7d and 28d. During this period, water pressure tests are carried out respectively. The water injection pipe 18 of the water pressure test device is connected to the grouting hole 9 of the model box, and the water injection pipe 18 is sealed with a sealer 19 and close to the wall of the grouting hole 9. Then water is injected into the model box 8 from the water supply pipe 27. After the water is filled, the change of the pressure value of the pressure gauge 20 is manually observed; in the process of continuous decline of the water level, the flow in the pipeline is directly measured by observing the second flow meter 21. When the internal water level reaches the designed position, the distance from the third part of the upper end of the grouting channel 9 to the third part of the lower end of the grouting channel 9 is used as the water pressure test section for flow calculation, and then the loss time used for the water level to drop in the water pressure test section is recorded, and finally the permeability of the node agglomerates in different time periods is detected.

[0048] The above-mentioned specific implementation methods are used to explain the present invention and are only preferred embodiments of the present invention, rather than limiting the present invention. Within the spirit of the present invention and the scope of protection of the claims, any modifications, equivalent replacements, improvements, etc. made to the present invention shall fall within the scope of protection of the present invention.

Claims

1. A test device for measuring the anti-seepage effect of sequential hole grouting, characterized by: Including grouting system, model box, water pressure test system; The grouting system includes an air compressor, an air pressure regulating valve, a grouting pipe, and a grouting bucket. The air compressor outlet is provided with an air pressure regulating valve, the top of the grouting bucket is provided with a first top plate, the first top plate is provided with a grouting valve, a grouting pipe is provided between the air pressure regulating valve and the grouting valve, and a grouting hole is provided on the side of the grouting bucket near the bottom; The model box consists of a semi-cylinder with an open top and a second top plate. A grouting channel is provided at the center of the semi-circle of the model box. Grouting ports are provided at two trisection points on the grouting channel respectively. A grouting pipe is provided between the grouting port and the grouting bucket. A plurality of shower-shaped small holes are provided at the upper and lower trisections of the grouting channel. The second top plate is provided on the top of the semi-cylinder. A row of drainage holes is provided at the bottom of the flat side of the model box. The water pressure test system is composed of a water supply pipeline, a water injection pump, a water injection meter, a one-way valve, a high-pressure hose, a valve, a second flow meter, a pressure gauge, and a water injection pipe in sequence. The water injection pipe is connected to the grouting channel, and a sealer is provided in the gap between the water injection pipe and the grouting channel.

2. The test device for measuring the anti-seepage effect of sequential hole grouting according to claim 1, characterized in that: The grouting pipe in the grouting system is a reinforced pumping pipe with a pressure resistance of more than 10 MPa.

3. The test device for measuring the anti-seepage effect of sequential hole grouting according to claim 1, characterized in that: The plane of the model box is made of transparent material.

4. The test device for measuring the anti-seepage effect of sequential hole grouting according to claim 1, characterized in that: A pressure gauge and a first flow meter are provided on the grouting pipeline between the grouting port and the grouting barrel.

5. The test device for measuring the anti-seepage effect of sequential hole grouting according to claim 4, characterized in that: The pressure meter and the first flow meter are connected to a computer.

6. The test device for measuring the anti-seepage effect of sequential hole grouting according to claim 1, characterized in that: A camera is provided on the outside of the plane side of the model box.

7. The test device for measuring the anti-seepage effect of sequential hole grouting according to claim 1, characterized in that: The first top plate is connected to the grouting bucket through fine steel screws.

8. The test device for measuring the anti-seepage effect of sequential hole grouting according to claim 1, characterized in that: The second top plates are connected to the model box via fine steel screws.

9. The test device for measuring the anti-seepage effect of sequential hole grouting according to claim 1, characterized in that: A rubber pad is provided between the model box plates, and a rigid curing sealant is provided at the connection.

10. The test device for measuring the anti-seepage effect of sequential hole grouting according to claim 1, characterized in that: The high-pressure hose in the water pressure test system is a transparent steel wire spiral reinforced hose with a pressure resistance of more than 4MPa.

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