Method for Detecting Sealing Performance at Joints of Cut-off Walls

Abstract

The present invention is a method for detecting the sealing performance at the connection of cut-off walls, characterized in that a water stop strip is arranged in the cavity at the connection end within the cut-off wall. The water stop strip is electrically connected to the positive pole of the detection end through a first conducting wire. The negative pole of the detection end is connected to the top end of a second conducting wire. The bottom end of the second conducting wire is connected to a heavy hammer and descends to the top position of the sealant. The detection end is signal-connected to the display end. The detection end provides a constant current. The display end collects the negative voltage value corresponding to each tap position of the negative cable of the second conducting wire. When the resistance value decreases, the negative voltage value collected by the display end also decreases, thereby determining that the connection end at this place is in an unclosed state. The present invention overcomes the limitations of traditional methods for detecting sealing performance and provides a detection method for realizing multi-frequency, efficient, and accurate detection of the sealing performance at the connection of ultra-long flexible vertical cut-off walls in a narrow-spacing and ultra-deep mud environment.

Description

Technical Field

[0001] The present invention relates to a method for detecting the sealing performance at the connection of cut-off walls. Background Art

[0002] For the treatment project of contaminated sites, especially for contaminated sites where the pollution source cannot be removed, since it is difficult to carry out the bottom horizontal anti-pollution construction subsequently, constructing a vertical cut-off wall around the site will become the main choice at this time. Among them, whether there are leakage points at the connection of the cut-off wall actually affects the anti-seepage effect. The method for detecting the sealing performance at the connection of the cut-off wall is of great significance to the integrity of the flexible vertical cut-off wall (HDPE membrane) and the prevention of pollutant leakage.

[0003] Currently, the methods that can be used to detect the sealing performance include the water gun method, the electric spark method, the high-density resistivity method, etc. Such detection methods are mainly applied to the HDPE membrane anti-seepage structure on a plane. The detection process requires achieving the conductivity of the membrane surface by sprinkling water under a high-voltage electric field, and determining the sealing performance at the connection of the membrane surface by using the electrical and physical parameters of the detection area.

[0004] The above detection methods are mostly used for detecting the sealing performance at the connection of the HDPE membrane laid on a plane. However, in the process of detecting the sealing performance at the connection of the flexible vertical cut-off wall, there are certain limitations in the implementation of some detection processes, and it is difficult to perform multiple detections. Especially in the ultra-deep mud environment where the groove width is only 600 - 800 mm and the length of the connection of the HDPE membrane is 60 m, at this time, how to detect the sealing performance at the connection of the flexible vertical cut-off wall in the narrow-distance ultra-deep mud environment is a key problem. Summary of the Invention

[0005] The present invention provides a method for detecting the sealing performance at the connection of cut-off walls, which overcomes the limitations of the traditional methods for detecting the sealing performance, and provides a detection method for achieving multiple, efficient, and accurate detections of the sealing performance at the connection of the ultra-long flexible vertical cut-off wall in the narrow-distance ultra-deep mud environment.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A method for detecting the sealing performance at the connection of cut-off walls, characterized by comprising the following steps:

[0008] Step 1: The connection position of the first anti-seepage membrane and the second anti-seepage membrane in the cut-off wall is the connection end. A water-stop strip is arranged in the cavity at the connection end. The water column formed after the water-stop strip swells in the cavity is used as the positive electrode cable, and the water-stop strip is electrically connected to the positive electrode of the detection end through a first wire.

[0009] Step 2: The negative electrode of the detection end is connected to the top end of a second wire. The bottom end of the second wire is connected to a weight, and the weight is pulled down to the top position of the sealant through a nylon rope.

[0010] Step 3: The detection end can also be connected to the display end in a signal connection. Start the detection end. The detection end provides a constant current, and the display end collects the negative voltage values corresponding to each detection position on the negative electrode cable of the second wire.

[0011] Step 4: According to Ohm's law U = IR, in the case of a constant current, when the resistance value at the connection end decreases, the negative voltage value collected by the display end also decreases, and thus it can be determined that the connection end here is in a leak point state, so as to detect the sealing performance of the connection end.

[0012] For the method for detecting the sealing performance of the connection of the impervious wall, wherein: the male locking buckle of the first impervious membrane is fixedly connected to the female locking buckle of the second impervious membrane by snap connection. The fixed position of the male locking buckle and the female locking buckle is the connection end, and a water stop strip is arranged in the cavity of the female locking buckle.

[0013] For the method for detecting the sealing performance of the connection of the impervious wall, wherein: the bottom inside the impervious wall is backfilled and blocked by the sealant, and then mud is poured into the impervious wall. The first impervious membrane and the second impervious membrane are immersed in the mud, and the depth of the mud is ≤ 60m.

[0014] For the method for detecting the sealing performance of the connection of the impervious wall, wherein: the width of the impervious wall is 600 - 800 mm, and the depth of the sealant is 5 - 10 m.

[0015] The beneficial effects of the present invention: It overcomes the limitations of the traditional method for detecting the sealing performance, and provides a detection method for realizing multi - frequency, efficient and accurate detection of the sealing performance of the connection of the ultra - long flexible vertical impervious wall in a narrow - spacing and ultra - deep mud environment. Description of the Drawings

[0016] Figure 1 It is a structural diagram of the connection method for the method for detecting the sealing performance of the connection of the impervious wall.

[0017] Figure 2 It is a front - view structural diagram of the connection method for the method for detecting the sealing performance of the connection of the impervious wall.

[0018] Figure 3 It is a top - view structural diagram of the connection method for the method for detecting the sealing performance of the connection of the impervious wall.

[0019] Figure 4 It is a structural diagram of the connection end.

[0020] Figure 5 It is an embodiment of the detection result for the method for detecting the sealing performance of the connection of the impervious wall.

[0021] Figure 6 Another embodiment of the test result for the method of detecting the sealing performance at the connection of the impervious wall.

[0022] Explanation of reference numerals: 1 - detection end; 2 - display end; 3 - impervious wall; 4 - first conductive wire; 5 - second conductive wire; 6 - water stop strip; 7 - sealant; 8 - connection end; 9 - slurry; 10 - first impervious membrane; 11 - second impervious membrane; 12 - male locking buckle; 13 - female locking buckle. Detailed implementation manner

[0023] As Figures 1 to 6 shown, a method for detecting the sealing performance at the connection of the impervious wall is characterized by including the following steps:

[0024] Step 1: The connection position of the first impervious membrane 10 and the second impervious membrane 11 in the impervious wall 3 is the connection end 8. A water stop strip 6 is arranged in the cavity of the connection end 8. The water column formed after the water stop strip 6 swells when encountering water in the cavity serves as the positive electrode cable, and the water stop strip 6 is electrically connected to the positive electrode of the detection end 1 through the first conductive wire 4;

[0025] Step 2: The negative electrode of the detection end 1 is connected to the top end of the second conductive wire 5. The bottom end of the second conductive wire 5 is connected to a plumb bob and is pulled down to the top position of the sealant 7 through a nylon rope;

[0026] Step 3: The detection end 1 can also be signal - connected to the display end 2. When the detection end 1 is started, the detection end 1 provides a constant current, and the display end 2 collects the negative electrode voltage values corresponding to each detection position on the negative electrode cable of the second conductive wire 5;

[0027] Step 4: According to Ohm's law U = IR, in the case of a constant current, when the resistance value at the connection end 8 decreases, the negative electrode voltage value collected by the display end 2 also decreases. Thus, it can be judged that the connection end 8 here is in a leakage point state, and the sealing performance of the connection end 8 is detected accordingly.

[0028] The bottom inside the impervious wall 3 is backfilled and blocked by the sealant 7, and then slurry 9 is poured into the impervious wall 3. The first impervious membrane 10 and the second impervious membrane 11 are immersed in the slurry 9. The width of the impervious wall 3 is 600 - 800 mm, the depth of the sealant 7 is 5 - 10 m, the depth of the slurry 9 is ≤60 m. The male locking buckle 12 of the first impervious membrane 10 is snap - fixed to the female locking buckle 13 of the second impervious membrane 11. The fixing position of the male locking buckle 12 and the female locking buckle 13 is the connection end 8, and the water stop strip 6 is arranged in the cavity of the female locking buckle 13.

[0029] In the embodiment, in order to detect whether the connection end 8 in the cutoff wall 3 is sealed, a water stop strip 6 is arranged in the cavity of the connection end 8. The water stop strip 6 is electrically connected to the positive electrode of the detection end 1 through a first conductive wire 4. The negative electrode of the detection end 1 is electrically connected to the top end of a second conductive wire 5. The bottom end of the second conductive wire 5 is connected to a plumb bob and is pulled down by a nylon rope to the top position of the sealant 7. The detection end 1 is also signal-connected to a display end 2. When the detection end 1 is started, the detection end 1 provides a constant current. The current flows out from the positive electrode of the detection end 1, flows into the water stop strip 6, then flows into the second conductive wire 5 through the slurry 9, and finally flows into the negative electrode of the detection end 1 to form an electrical circuit. According to Ohm's law U = IR, in the state of constant current, if the connection end 8 is in a leakage point state, at this time, the resistance value decreases, and then the negative voltage value collected by the display end 2 also decreases accordingly. It can be judged that the connection end 8 at the detection position is in a leakage point state by the decrease of the voltage value.

[0030] Through the comparison of the detection results of the sealing performance of the connection end 8 of the cutoff wall 3 by this detection method, Figure 5 the electrode number 1 shown corresponds to the bottom of the cutoff wall 3, the electrode number 40 corresponds to the top of the cutoff wall 3, the sampling value is the voltage value, the voltage value from the bottom to the top of the cutoff wall 3 shown in the figure is stable, and the display result is closed. Figure 6 The voltage value at the part with the electrode number 34 of the cutoff wall 3 shown drops sharply, and the display result is that there is a leakage point and it is not sealed well, providing an indication for the subsequent leakage point blocking work.

[0031] Advantages of the present invention:

[0032] It overcomes the limitations of the traditional method for detecting sealing performance and provides a detection method for realizing multi-frequency, efficient, and accurate detection of the sealing performance of the joints of an ultra-long flexible vertical cutoff wall in a narrow-spacing ultra-deep slurry environment.

[0033] The above description is illustrative rather than restrictive to the present invention. Those of ordinary skill in the art understand that many modifications, changes or equivalents can be made without departing from the spirit and scope defined by the claims, and all of them will fall within the protection scope of the present invention.

Claims

1. A method for detecting the sealing performance at the connection of cut-off walls, characterized in that It includes the following steps: Step 1: The connection position of the first anti-seepage membrane (10) and the second anti-seepage membrane (11) in the anti-seepage wall (3) is the connection end (8). A water-stop strip (6) is arranged in the cavity of the connection end (8). The water column formed after the water-stop strip (6) swells in the cavity serves as the positive cable, and the water-stop strip (6) is electrically connected to the positive electrode of the detection end (1) through the first conductive wire (4); Step 2: The negative electrode of the detection end (1) is connected to the top end of the second conductive wire (5). The bottom end of the second conductive wire (5) is connected to a plumb bob and is pulled down to the top position of the sealant (7) by a nylon rope; Step 3: The detection end (1) can also be signal-connected to the display end (2). When the detection end (1) is started, the detection end (1) provides a constant current, and the display end (2) collects the negative voltage values corresponding to each detection position on the negative cable of the second conductive wire (5); Step 4: According to Ohm's law U = IR, in the case of a constant current, the resistance value at the connection end (8) decreases, and the negative voltage value collected by the display end (2) also decreases accordingly. Then it is judged that the connection end (8) here is in a leak point state, so as to detect the sealing performance of the connection end (8).

2. The method for detecting the sealing performance at the connection of the cut-off wall according to claim 1, wherein: The male lock catch (12) of the first anti-seepage membrane (10) is snap-fixedly connected to the female lock catch (13) of the second anti-seepage membrane (11). The fixed position of the male lock catch (12) and the female lock catch (13) is the connection end (8), and the water-stop strip (6) is arranged in the cavity of the female lock catch (13).

3. The method for detecting the sealing performance at the connection of the impervious wall according to claim 1, characterized in that: The bottom inside the anti-seepage wall (3) is backfilled and blocked by the sealant (7), and then slurry (9) is poured into the anti-seepage wall (3). The first anti-seepage membrane (10) and the second anti-seepage membrane (11) are immersed in the slurry (9), and the depth of the slurry (9) is ≤ 60m.

4. The method for detecting the sealing performance at the connection of the cut-off wall according to claim 1, wherein: The width of the anti-seepage wall (3) is 600 - 800mm, and the depth of the sealant (7) is 5 - 10m.

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