CN213709647U

CN213709647U - Be used for foundation ditch stagnant water curtain leakage detection device

Info

Publication number: CN213709647U
Application number: CN202021857235.XU
Authority: CN
Inventors: 马龙; 张辉; 刘国; 贾辉; 白朝旭; 高宏伟; 孙玉辉; 赵翔
Original assignee: BGI ENGINEERING CONSULTANTS Ltd
Current assignee: BGI ENGINEERING CONSULTANTS Ltd
Priority date: 2020-08-31
Filing date: 2020-08-31
Publication date: 2021-07-16
Anticipated expiration: 2030-08-31

Abstract

The utility model discloses a leakage detection device for a foundation pit waterproof curtain, which comprises a waterproof curtain, a drill hole, an instrument host, a power supply electrode A, a loop electrode B infinity and an observation electrode; and the drill holes are distributed along the circumferential direction of the waterproof curtain. Arranging observation electrodes along the waterproof curtain within 3m of the waterproof curtain; keeping the position of a loop electrode B infinity, moving a power supply electrode A from the bottom of a hole to an orifice in sequence, and respectively carrying out potential gradient observation until the waterproof curtain detection work of the whole foundation pit is completed; and processing and analyzing the observed data to determine the position and scale of the leakage of the waterproof curtain. The utility model has strong practicability; the number of drilled holes is reduced, so that the detection cost is reduced, and the structure of the waterproof curtain is prevented from being damaged; the detection sensitivity and precision are high.

Description

Be used for foundation ditch stagnant water curtain leakage detection device

Technical Field

The utility model relates to a be arranged in foundation ditch stagnant water curtain seepage detection device, but the wide application is in different forms's such as cement soil stirring wall, underground continuous wall, secant pile foundation ditch stagnant water curtain for detect the position and the scale that the seepage took place for the stagnant water curtain.

Background

The waterproof curtain is a main technical measure for controlling the underground water in the deep foundation pit engineering and is mainly used for preventing the underground water from flowing into the foundation pit from the side wall or the bottom of the foundation pit. However, in engineering practice, due to the reasons of insufficient investigation of hydrogeological conditions, improper selection of water-stopping schemes, poor control of construction quality and the like, the water-stopping curtain is ineffective sometimes, so that a lot of foundation pit engineering accidents are caused. Therefore, if the leakage can be judged before the foundation pit is excavated and the position where the leakage occurs can be accurately detected, reinforcing and leaking stoppage measures can be taken in advance, and various risks caused by leakage of the waterproof curtain during excavation are avoided.

In the current foundation pit waterproof curtain leakage detection, the most common methods mainly comprise a high-density electrical method for measuring the resistivity change of two sides of a curtain before and after precipitation, a cross-hole resistivity CT, a cross-hole sound wave CT, a cross-hole resistivity CT, a seepage field method (potential method) and the like, but each method has certain limitations, for example, the development of high-density electrical method detection work needs an open field capable of laying a measuring line, the field cannot be hardened, and the urban foundation pit field is often difficult to meet the conditions; the cross-hole CT method is high in precision, but more drill holes need to be arranged along the foundation pit, so that the detection cost is increased, and the waterproof curtain structure is damaged; although the seepage field method (potential method) can detect the position where the seepage occurs, the precision is low, and the precision repair is not favorable.

SUMMERY OF THE UTILITY MODEL

In order to overcome the technical problem in the background art, the utility model discloses a technical scheme be:

a leakage detection device for a waterproof curtain of a foundation pit comprises a waterproof curtain 1, a drill hole 2, an instrument host 3, a power supply electrode A4, a loop electrode B infinity 5 and an observation electrode 6; the drill holes 2 are arranged at the positions of the inner side or the outer side of the waterproof curtain 1 at proper distances, and the depth of each drill hole 2 is equal to the height of the waterproof curtain 1; the power supply electrode A4 is positioned in the drill hole 2, and the loop electrode B ∞ 5 is positioned outside the waterproof curtain 1; the observation electrode 6 is positioned at the inner side of the waterproof curtain 1 and is distributed along the circumferential direction of the waterproof curtain 1; the power feeding electrode A4, the return electrode B ∞ 5 and the observation electrode 6 are connected to the apparatus main unit 3.

Furthermore, the waterproof curtain is a cement soil mixing wall, an underground continuous wall or an occlusive pile and the like.

Further, the borehole 2 is required to be open hole and the open hole is filled with water or slurry.

Further, the instrument main unit 3 is an electrical method instrument.

Further, the feeding electrode a4 and the return electrode B ∞ 5 are copper electrodes, and the observation electrode 6 is a non-polarized electrode.

Further, a drill hole 2 is arranged at a proper position inside or outside the foundation pit, the drill hole 2 is required to be drilled to the depth of the bottom plate of the foundation pit, and the distance between the drill hole 2 and the waterproof curtain 1 is measured.

Further, the loop electrode B ∞ 5 is laid at a suitable position more than 5 times the length of the curtain 1 to be detected from the borehole 2.

Further, an observation electrode 6 (namely a potential gradient observation device MN) is arranged along the waterproof curtain within 3m from the waterproof curtain 1, and potential gradient changes in the direction parallel to the waterproof curtain 1 and the direction perpendicular to the waterproof curtain 1 are respectively observed and recorded;

further, while the position of the return electrode B ∞ 5 is kept unchanged, the power supply electrode a4 is sequentially moved from the bottom of the hole to the opening of the hole, and potential gradient observation is performed until the waterproof curtain detection work of the entire foundation pit is completed.

Furthermore, the observation data are processed and analyzed, and the position and the scale of the leakage of the waterproof curtain can be determined.

The utility model has the advantages that: (1) the detection conditions are few, and the practicability is strong; (2) the number of drilled holes is reduced, so that the detection cost is reduced, and the structure of the waterproof curtain is prevented from being damaged; (3) the detection sensitivity and precision are high.

Drawings

Fig. 1 is a schematic view of the observation device of the present invention.

Fig. 2 is a schematic plan view of the observation device of the present invention.

FIG. 3 is a diagram of the results of the seepage test of the cement-soil mixing wall.

In the figure: 1. a waterproof curtain; 2. drilling; 3. an instrument host; 4. a power feeding electrode A; 5. loop electrode B (∞); 6. and (6) observing the electrode.

Detailed Description

The present invention will be further explained by way of examples with reference to the accompanying drawings.

1-2, the device comprises a waterproof curtain 1, a drill hole 2, an instrument host 3, a power supply electrode A4, a loop electrode B ∞ 5 and an observation electrode 6; the borehole 2 is arranged at a proper position inside or outside the waterproof curtain 1, the depth of the borehole 2 is required to reach the bottom of the waterproof curtain 1, the power supply electrode A4 is positioned in the borehole 2, the loop electrode B infinity 5 is positioned at a proper position outside the waterproof curtain, which is more than 5 times the length of the waterproof curtain to be detected from the borehole 2, and the observation electrode 6 is positioned within 3m of the inner side of the waterproof curtain 1 and arranged along the waterproof curtain 1.

The utility model discloses a be used for foundation ditch stagnant water curtain seepage detection device, its concrete implementation process as follows: arranging a drill hole 2 at a proper position inside or outside the foundation pit, wherein the drill hole 2 is required to be drilled to the depth of the bottom plate of the foundation pit, and measuring the distance from the drill hole 2 to the waterproof curtain 1; a power supply electrode A4 is arranged at the bottom of the drill hole 2, and a loop electrode B ∞ 5 is arranged at a proper position which is more than 5 times the length of the curtain to be detected away from the drill hole; arranging a potential gradient observation device MN along the waterproof curtain within 3m from the waterproof curtain 1, respectively observing potential gradient changes in the direction parallel to the waterproof curtain and the direction vertical to the waterproof curtain, and recording; keeping the position of a loop electrode B infinity 5 unchanged, sequentially moving a power supply electrode A4 from the bottom of a hole to an orifice, and respectively carrying out potential gradient observation until the waterproof curtain detection work of the whole foundation pit is completed; and processing and analyzing the observed data to determine the position and scale of the leakage of the waterproof curtain.

Utilize the utility model provides a method and device detect a beijing certain foundation ditch cement soil mixing wall stagnant water curtain, and the detection effect is seen in figure 3, and is visible, and near the stagnant water curtain of south side wall stake number-1 m has the seepage, and this result is unanimous with the probing result.

Claims

1. The utility model provides a be used for foundation ditch stagnant water curtain seepage detection device which characterized in that: the device comprises a waterproof curtain (1), a drill hole (2), an instrument host (3), a power supply electrode A (4), a loop electrode B ∞ (5) and an observation electrode (6); the drill holes (2) are arranged on the inner side or the outer side of the waterproof curtain (1), and the depth of the drill holes (2) is equal to the height of the waterproof curtain (1); the power supply electrode A (4) is positioned in the drill hole (2), and the loop electrode B ∞ (5) is positioned outside the waterproof curtain (1); the observation electrode (6) is positioned on the inner side of the waterproof curtain (1) and is distributed along the circumferential direction of the waterproof curtain (1); the power supply electrode A (4), the loop electrode B ∞ (5) and the observation electrode (6) are all connected with the instrument host (3).

2. The device for detecting the leakage of the waterproof curtain of the foundation pit as claimed in claim 1, wherein: the waterproof curtain is a cement soil mixing wall, an underground continuous wall or an occlusive pile.

3. The device for detecting the leakage of the waterproof curtain of the foundation pit as claimed in claim 1, wherein: the drilling hole (2) is required to be an open hole, and the open hole is filled with water or slurry.

4. The device for detecting the leakage of the waterproof curtain of the foundation pit as claimed in claim 1, wherein: the instrument host (3) is an electrical method instrument.

5. The device for detecting the leakage of the waterproof curtain of the foundation pit as claimed in claim 1, wherein: the feeding electrode A (4) and the return electrode B ∞ (5) are copper electrodes, and the observation electrode (6) is a non-polarized electrode.

6. The device for detecting the leakage of the waterproof curtain of the foundation pit as claimed in claim 1, wherein: the observation electrode (6) respectively observes the potential gradient changes in the direction parallel to the waterproof curtain (1) and the direction vertical to the waterproof curtain (1).