Cement slurry stability detection device and method

Abstract

The present invention discloses a cement slurry stability detection device, which includes a detection barrel, the upper end of the detection barrel is open, a plurality of pressure boxes are arranged on the inner wall of the detection barrel, a display screen is arranged on the outer wall of the detection barrel, and the pressure boxes and the display screen are electrically connected to a processor; a demoulding air hole is arranged at the bottom of the detection barrel. A method for cement slurry stability is provided, which includes: the pressure box collects the pressure value of solidified cement, draws a curve chart of the pressure value changing with the depth of the detection barrel, and calculates the stability deviation α between the depth change curve and the standard curve A , calculate the stability deviation α of another cement slurry B , and compare and analyze the results. This scheme is different from the previous method of using cement slurry bleeding rate to evaluate stability. This scheme uses a stability evaluation method with higher precision and more accuracy.

Description

Technical Field

[0001] The invention relates to the technical field of shield grouting, and in particular to a cement slurry stability detection device and method. Background Art

[0002] During the shield tunneling process, since the outer diameter of the shield cutterhead is larger than the outer diameter of the lining segment, and the shield shell has a certain thickness, in addition, there are phenomena such as over-excavation during the excavation process. After the shield tail is separated from the segment, an annular gap will appear between the segment and the stratum. At this time, the soil around the segment is in an unsupported state. This gap is the shield tail gap. If measures are not taken in time to deal with the shield tail gap, the segment may be deformed and dislocated due to lack of constraint under the action of the jack. In addition, the stratum deformation gradually increases, which will eventually lead to excessive surface settlement. Therefore, at the same time as the shield tail gap is formed, the synchronous grouting system is used to inject cement slurry materials with appropriate early strength and final strength from the grouting holes of the shield tail according to the specified grouting volume and grouting pressure to fill the shield tail gap, so that the soil around the segment can be supported in time, which can effectively prevent soil collapse and control surface settlement.

[0003] At present, the methods for evaluating the stability of cement slurry are relatively simple and only apply to single-liquid slurry. There are fewer methods for evaluating the stability of fast-setting slurries such as double-liquid slurry. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a cement slurry stability detection device and method which can realize stability evaluation of various cement slurries.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0006] A cement slurry stability detection device is provided, which comprises a detection barrel, the upper end of the detection barrel is open, a plurality of pressure boxes are arranged on the inner wall of the detection barrel, and the pressure boxes are embedded in the detection barrel; the plurality of pressure boxes are distributed in an S shape from top to bottom in the detection barrel, and the plurality of pressure boxes are evenly distributed, a display screen is arranged on the outer wall of the detection barrel, and the pressure boxes and the display screen are both electrically connected to a processor; and a demoulding air hole is arranged at the bottom of the detection barrel.

[0007] A method for evaluating cement slurry stability using a cement slurry stability detection device is provided, comprising the following steps:

[0008] S1: Pour cement slurry A into the detection barrel from the upper opening of the detection barrel, making sure that the cement slurry covers all the pressure boxes;

[0009] S2: Let the cement slurry A stand still to solidify, and the pressure box collects the pressure values ​​of the cement slurry A at different depths of the detection barrel after solidification;

[0010] S3: The pressure value collected by each pressure box is sent to the processor;

[0011] S4: The processor uses the depth of the detection barrel as the vertical coordinate and the pressure values ​​collected by each pressure box as the horizontal coordinate to draw a curve chart of the pressure value versus the depth of the detection barrel;

[0012] S5: Draw a standard curve of the lateral pressure and depth change of cement slurry A when it is absolutely stable in the test barrel;

[0013] S6: Calculate the stability deviation α between the depth change curve and the standard curve A :

[0014]

[0015] Among them, p bi is the pressure value of cement slurry A measured by the pressure box at a certain measuring point i, p ai is the lateral pressure at measuring point i when the cement slurry is absolutely stable, and n is the number of pressure cells;

[0016] S7: Take another test bucket, pour cement slurry B into the test bucket, repeat steps S1-S6, and calculate the stability deviation α of cement slurry B B ;

[0017] S8: Compare the deviation between cement slurry B and cement slurry A. If α B >α A , then cement slurry B is more stable. B <α A , then cement slurry A is more stable, otherwise, cement slurry B and cement slurry A have the same stability.

[0018] The beneficial effects of the present invention are as follows: the present invention is used to detect the stability of different types of cement slurries. By injecting cement slurries of different proportions into the detection barrel, the stability of the cement slurries as the depth changes can be detected. The detection device of the present invention has a simple structure and is easy to operate. It is not only suitable for the detection of a single type of cement slurry, but also for multiple cement slurries or quick-setting cement slurries. The present invention is different from the previous method of evaluating the stability by using the water seepage rate of cement slurry. The present invention adopts a stability evaluation method with higher precision and accuracy.

[0019] The detection barrel of this scheme has a simple structure. The pressure box can detect the lateral pressure of cement at different positions, and the lateral pressure is evenly distributed. The measurement result is accurate. The display screen is used to display the detected pressure value. The demoulding pores are convenient for removing the solidified cement after the detection is completed. The detection barrel can be recycled. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of a cement slurry stability detection device.

[0021] Figure 2 This is a structural diagram for detecting the bottom of the barrel.

[0022] Figure 3 It is a top view of the mobile seat.

[0023] Figure 4 This is a bottom view of the detection barrel.

[0024] Figure 5 This is a curve of the cement slurry side pressure changing with depth.

[0025] Among them, 1. demoulding pores, 2. detection barrel, 3. supporting feet, 4. sealing screws, 5. handles, 6. rubber pads, 7. pressure box, 8. display screen, 9. mobile seat, 10. casters, 11. placement slots, and 12. through holes. DETAILED DESCRIPTION

[0026] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0027] like Figures 1 to 4 As shown, the cement slurry stability detection device of the present scheme includes a detection barrel 2, the upper end of the detection barrel 2 is open, and a plurality of pressure boxes 7 are arranged on the inner wall of the detection barrel 2, and the pressure boxes 7 are embedded in the detection barrel 2; the plurality of pressure boxes 7 are distributed in an S shape from top to bottom in the detection barrel 2, and the plurality of pressure boxes 7 are evenly distributed, a display screen 8 is arranged on the outer wall of the detection barrel 2, and the pressure boxes 7 and the display screen 8 are both electrically connected to the processor; a demolding air hole 1 is arranged at the bottom of the detection barrel 2.

[0028] The detection barrel 2 of the present solution has a simple structure, the pressure box 7 can detect the lateral pressure of cement at different positions, and the lateral pressure is evenly distributed, the measurement result is accurate, the display screen 8 is used to display the detected pressure value, the demoulding pores 1 are convenient for removing the solidified cement after the detection is completed, and the detection barrel 2 can be recycled.

[0029] The detection barrel 2 is placed on the mobile seat 9. A placement groove 11 is provided at the upper end of the mobile seat 9. A through hole 12 is provided in the center of the placement groove 11. Casters 10 are provided on the four feet at the bottom of the mobile seat 9. The detection barrel 2 is placed on the mobile seat 9 for easy movement and transportation. At the same time, the placement groove 11 can ensure that the detection barrel 2 is stably placed on the mobile seat 9. Handles 5 are provided on both sides of the upper end of the detection barrel 2 to facilitate the detection barrel 2 to be lifted out of the mobile seat 9.

[0030] A circle of rubber pads 6 are fixed around the bottom of the placement groove 11. The rubber pads 6 can fill the gap between the detection barrel 2 and the placement groove 11, clamp the detection barrel 2, and further ensure stability. At the same time, it can reduce the collision between the detection barrel 2 and the moving seat 9, thereby reducing damage to the detection barrel 2 and the moving seat 9.

[0031] A threaded hole is provided at the lower end of the demoulding air hole 1, and a sealing screw 4 is provided in the threaded hole. The sealing screw 4 is threadedly connected to the threaded hole. During the inspection process, the sealing screw 4 blocks the demoulding air hole 1 to prevent cement slurry from flowing out of the demoulding air hole 1. After the inspection is completed, the sealing screw 4 is removed to facilitate demoulding.

[0032] A supporting foot 3 is provided at the bottom of the detection barrel 2 , and the supporting foot 3 can suspend the bottom of the detection barrel 2 to avoid damaging the bottom surface of the detection barrel 2 .

[0033] The method for evaluating the stability of cement slurry using the cement slurry stability detection device of the present scheme comprises the following steps:

[0034] S1: Pour cement slurry A into the detection barrel 2 from the upper opening of the detection barrel 2, ensuring that the cement slurry covers all the pressure boxes 7;

[0035] S2: Let the cement slurry A stand still until it solidifies, and the pressure box 7 collects the pressure values ​​of the cement slurry A at different depths of the detection barrel 2 after solidification;

[0036] S3: The pressure values ​​collected by each pressure box 7 are sent to the processor. In this solution, 12 pressure boxes 7 are arranged in the detection barrel 2;

[0037] S4: The processor uses the depth of the detection barrel 2 as the ordinate and the pressure values ​​collected by each pressure box 7 as the abscissa to draw a curve of the pressure value versus the depth of the detection barrel 2, such as Figure 5 As shown;

[0038] S5: draw a standard curve of the lateral pressure and depth change of cement slurry A when it is absolutely stable in the detection barrel 2;

[0039] S6: Calculate the stability deviation α between the depth change curve and the standard curve A :

[0040]

[0041] p ai =k ai γz

[0042] Among them, k ai is the lateral pressure of the water slurry at the measuring point i when it is absolutely stable, γ is the lateral pressure coefficient of the water slurry at the measuring point i when it is absolutely stable, z is the gravity of the water slurry at the measuring point i when it is absolutely stable, p biis the pressure value of cement slurry A measured by pressure cell 7 at a certain measuring point i, p ai is the lateral pressure at the measuring point i when the cement slurry is absolutely stable, and n is the number of pressure cells 7;

[0043] The smaller the deviation, the closer the curve of lateral pressure change with depth is to the standard curve, and the more stable the cement slurry is.

[0044] S7: Take another test bucket 2, pour cement slurry B into the test bucket 2, repeat steps S1-S6, and calculate the stability deviation α of cement slurry B B ;

[0045] S8: Compare the deviation between cement slurry B and cement slurry A. If α B >α A , then cement slurry B is more stable. B <α A , then cement slurry A is more stable, otherwise, cement slurry B and cement slurry A have the same stability.

[0046] The beneficial effects of the present invention are as follows: the present solution is used to detect the stability of different types of cement slurries. By injecting cement slurries of different proportions into the detection barrel 2, the stability of the cement slurries as the depth changes can be detected. The detection device of the present solution has a simple structure and is easy to operate. It is not only suitable for the detection of a single type of cement slurry, but also for multiple cement slurries or quick-setting cement slurries. The present solution is different from the previous method of evaluating stability by using the water seepage rate of cement slurry. The present solution uses a stability evaluation method with higher precision and more accuracy.

Claims

1. A method for evaluating cement slurry stability using a cement slurry stability detection device, the cement slurry stability detection device comprising a detection barrel (2), the upper end of the detection barrel (2) is open, a plurality of pressure boxes (7) are arranged on the inner wall of the detection barrel (2), and the pressure boxes (7) are embedded in the detection barrel (2); the plurality of pressure boxes (7) are distributed in an S shape from top to bottom in the detection barrel (2), and the plurality of pressure boxes (7) are evenly distributed; a display screen (8) is arranged on the outer wall of the detection barrel (2), and the pressure box (7) and the display screen (8) are both electrically connected to a processor; and a demoulding air hole (1) is arranged at the bottom of the detection barrel (2); The detection barrel (2) is placed on a movable seat (9), a placement groove (11) is provided at the upper end of the movable seat (9), a through hole (12) is provided at the center of the placement groove (11), and casters (10) are provided on the four feet at the bottom of the movable seat (9); Rubber pads (6) are arranged around the bottom of the placement groove (11); A threaded hole is provided at the lower end of the demoulding air hole (1), a sealing screw (4) is provided in the threaded hole, and the sealing screw (4) is threadedly connected to the threaded hole; Handles (5) are provided on both sides of the upper end of the detection barrel (2); The bottom of the detection barrel (2) is provided with supporting feet (3); It is characterized in that The following steps are involved: S1: Pour cement slurry A into the detection barrel (2) from the upper opening of the detection barrel (2), ensuring that the cement slurry covers all the pressure boxes (7); S2: standing still to wait for the cement slurry A to solidify, and the pressure box (7) collects the pressure values ​​of the cement slurry A at different depths of the detection barrel (2) after solidification; S3: The pressure values ​​collected by each pressure box (7) are sent to the processor; S4: The processor uses the depth of the detection barrel (2) as the ordinate and the pressure values ​​collected by each pressure box (7) as the abscissa to draw a curve of the pressure value versus the depth of the detection barrel (2); S5: drawing a standard curve of the lateral pressure and depth change of cement slurry A when it is absolutely stable in the detection barrel (2); S6: Calculate the stability deviation α between the depth change curve and the standard curve A : Among them, p bi is the pressure value of cement slurry A measured by the pressure cell (7) at a certain measuring point i, p ai is the lateral pressure at the measuring point i when the cement slurry is absolutely stable, and n is the number of pressure cells 7; S7: Take another test bucket (2), pour cement slurry B into the test bucket (2), repeat steps S1-S6, and calculate the stability deviation α of cement slurry B B ; S8: Compare the deviation between cement slurry B and cement slurry A. If α B >α A , then cement slurry B is more stable. B <α A , then cement slurry A is more stable, otherwise, the stability of cement slurry B and cement slurry A is the same.

2. The method for evaluating cement slurry stability by the cement slurry stability detection device according to claim 1, characterized in that: The side pressure p ai =k ai γz, where k ai is the lateral pressure when the water slurry at measuring point i is absolutely stable, γ is the lateral pressure coefficient when the water slurry at measuring point i is absolutely stable, and z is the gravity when the water slurry at measuring point i is absolutely stable.

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