CN-122016163-A - Foundation pit groundwater leakage path detection and restoration effect detection method

CN122016163ACN 122016163 ACN122016163 ACN 122016163ACN-122016163-A

Abstract

The invention provides a method for detecting a leakage path of underground water of a foundation pit and detecting a repairing effect, which is characterized by comprising the steps of S1, detecting an out-of-pit leakage path, S2, installing a leakage path detection system, S3, confirming a leakage path in the pit, S4, repairing the leakage, repeating S1, detecting the repairing effect, and repeating S2-S4 until the leakage detection result is qualified. The invention uses the pre-buried inclinometer pipe as a detection tool, and on the basis of not affecting the original strength of the underground diaphragm wall, the leakage joint is rapidly judged by detecting the leakage path inside and outside the pit, the accurate positioning is carried out on the leakage path and the leakage point position, and the rapid detection of the leakage blocking effect is realized.

Inventors

CHENG ZICONG
CHEN FENGJUN
WANG QILING
ZHOU QUANJI

Assignees

上海建工集团股份有限公司

Dates

Publication Date: 20260512
Application Date: 20251231

Claims (14)

1. A method for detecting the leakage path of foundation pit underground water and the repairing effect is characterized in that, S1, detecting an out-pit leakage path; s2, installing a leakage path detection system; s3, confirming a seepage path in the pit; S4, performing leakage repair, repeating the step S1 to perform repair effect detection, and repeating the step S2-S4 if the leakage detection result is not qualified, until the leakage detection result is qualified.
2. The method for detecting and repairing the leakage path of foundation pit groundwater according to claim 1, wherein S1 further comprises a foundation pit excavation stage, wherein different color water bodies are injected into a plurality of preset inclinometer pipes, the colors of groundwater in a precipitation well outside the pit are observed after a plurality of times, the inclinometer pipes are positioned in a foundation pit wall joint, and holes are formed in the pipe body of the inclinometer pipes; When the water color of the dewatering well near the inclinometer pipe is unchanged, the joint where the inclinometer pipe is positioned is not provided with an out-of-pit seepage path, and S2-S4 are not needed; when the water in the dewatering well near the inclinometer pipe changes to a specific color, judging that leakage exists at the joint of the inclinometer pipe injected into the water body with the specific color, and performing S2-S4.
3. The method for detecting and repairing the underground water leakage path of the foundation pit according to claim 1, wherein the leakage path detection system in the step S2 comprises an iron nail, an electrode sensor, a moving device, an antiwear hydraulic line, an electric signal receiver, a power supply, an inclinometer and a current detection device, wherein the iron nail is driven into soil bodies in the inner side of the surrounding walls at two sides of a joint and in pits at the periphery of the joint, the iron nail is connected with the electrode sensor, the moving device is provided with the electric signal receiver, the electrode sensor is connected with the electric signal receiver through the antiwear hydraulic line, the power supply is arranged near the joint to be detected, two wires are connected to the outside, one wire is connected into the inclinometer at the joint, the other wire is connected with the current detection device, the electric signal receiver is connected with the current detection device, and a hole is formed in the pipe body of the inclinometer.
4. The method for detecting the leakage path of the foundation pit groundwater and detecting the repairing effect according to claim 3, wherein if the excavation depth of the foundation pit is more than or equal to 3 meters, the iron nails are driven into the maintenance wall to a depth of 2-3cm, and the depth of the driven iron nails into the soil body of the foundation pit is more than or equal to 5cm.
5. A method for detecting a leakage path of foundation pit groundwater and detecting a repairing effect according to claim 3, wherein if the excavation depth of the foundation pit is less than 3 meters, the iron nails only need to be driven into soil in the pit around the joint, and the driving depth of the iron nails is 3-8cm.
6. The method for detecting and repairing the underground water leakage path of the foundation pit according to claim 3, wherein the iron nails are arranged in soil bodies at two sides of the joint, 2 rows are respectively arranged on enclosure walls at two sides of the joint, the height and the width of the iron nails are arranged at intervals of 2m, the distance between the top of each row of enclosure walls is 0.8-1.2m, the soil bodies in the foundation pit along the enclosure direction and the vertical enclosure direction are arranged at intervals of 1.5m, and the two sides of the joint are respectively arranged at intervals of 3 rows.
7. The method for detecting and repairing the leakage path of foundation pit groundwater according to claim 6, wherein the iron nails are arranged in soil bodies at two sides of the joint, and are preferentially arranged at the wet points.
8. A method for detecting a leakage path of foundation pit groundwater and detecting a repairing effect according to claim 3, wherein the current detecting means is an electrometer type current measuring instrument.
9. The method for detecting and repairing a foundation pit groundwater leakage path according to claim 3, wherein in S3, electrolyte brine is added into the inclinometer pipe, or the color water of S1 contains electrolyte salt.
10. The method for detecting a leakage path and repairing effect of foundation pit groundwater according to claim 3, wherein S3 further comprises: S3-1, connecting all electrode sensors on the soil body in the enclosure wall and the pit with an electric signal receiver, if current exists, leaking, and performing S3-2; S3-2, disconnecting all the electrical signal receiver from the soil electrode sensor in the pit, and if current exists, leaking the enclosure wall, S3-3, and if no current exists, no leakage exists in the enclosure wall, S3-4; S3-3, disconnecting the electrode sensors on the enclosure walls, selecting one enclosure wall electrode sensor to be connected with the electric signal receiver, removing the connection after recording the current value, and then connecting the next enclosure wall electrode sensor with the electric signal receiver until all the enclosure wall electrode sensors are connected with the electric signal receiver in sequence, wherein the current detection device in the leakage path detection system has current passing, the corresponding point position of the electrode sensor is the leakage path passing point, the electrode sensor point position corresponding to the maximum value of the current is the center leakage position; S3-4, all electrode sensors on the enclosure wall are disconnected, one pit soil electrode sensor is selected to be connected with an electric signal receiver, the connection is disconnected after the current value is recorded, then the next pit soil electrode sensor is connected with the electric signal receiver until the pit soil electrode sensor is connected with the electric signal receiver in sequence, when the current detection device in the leakage path detection system has current passing, the electrode sensor corresponding point position is the leakage path passing point, and the electrode sensor point position corresponding to the current maximum value is the center leakage position.
11. The method for detecting and repairing a seepage path of foundation pit groundwater according to claim 3, wherein S3 further comprises connecting electrode sensors with the electric signal receiver one by one, confirming whether current passes through and recording the current value, and finding out the electrode sensor point position corresponding to the maximum value of the current, namely the seepage position.
12. The method for detecting and repairing the leakage path of foundation pit groundwater according to any one of claims 10 to 11, wherein the area leakage is repaired by taking the electrode sensor point corresponding to the maximum value of current as the center and covering all the leakage path passing points.
13. The method for detecting the leakage path of foundation pit groundwater and detecting the repairing effect according to claim 2, wherein in the construction stage of the diaphragm wall, the inclinometer pipes are additionally fixed in advance at the joint positions of the two ends of the reinforcement cage, so that the inclinometer pipes are ensured to be positioned at the joint positions of the two ends of the diaphragm wall after the diaphragm wall is poured.
14. The method for detecting the leakage path and the repairing effect of the foundation pit groundwater according to claim 2, wherein the diameter of the hole of the inclinometer pipe body is 1.5-2mm, 6 holes are uniformly distributed along the radial circumference of the pipe body, and the distribution interval of each layer is 0.8-1.2m.

Description

Foundation pit groundwater leakage path detection and restoration effect detection method Technical Field The invention belongs to the technical field of detection of building construction engineering, and particularly relates to a rapid detection and repair quality rapid inspection method for a foundation pit excavation stage underground water leakage path. Background Foundation pit engineering is more and more, and because of the restriction of geology and foundation conditions, many foundation pits have certain geological disaster risks, such as ground subsidence, soil erosion, rock stratum collapse and the like. Therefore, in order to ensure construction safety and smooth progress of other related projects, the foundation pit needs to be monitored when the foundation pit is excavated, and the foundation pit is generally arranged at joints and representative positions in side slopes of the foundation pit and enclosure (pile) walls, buried in soil bodies with a certain depth (generally 1.5-2 times of the depth of the foundation pit), and symmetrically distributed at two sides of the foundation pit according to a design drawing in quantity and interval, but at least 1 inclinometer is arranged at each side, wherein the inclinometer is used for measuring geological survey of relative trend and movement of a geological structure. Meanwhile, in order to avoid geological disasters, supporting structures such as a diaphragm wall (a diaphragm wall, an underground diaphragm wall) or a retaining wall are arranged before the foundation pit is excavated, joints exist in the diaphragm wall due to sectional construction, the joints are the places where the construction quality problem is most likely to occur, holes appear in the joints of the diaphragm wall due to the fact that concrete is not poured in place, and underground water leaks from the outside of the foundation pit to the inside of the pit at the joint part of the diaphragm wall after the foundation pit is excavated. The leakage water weakens the bearing capacity and rigidity of the underground continuous wall, so that the deformation of the foundation pit supporting system is increased, the inclination of the wall, the cracking or the local collapse of joints can be caused, the construction safety is seriously threatened, and if the leakage point is enlarged, piping or sand flow can be formed, the soil loss of the side wall of the foundation pit is further aggravated, and the whole supporting structure is invalid. At present, although the leakage prediction condition of a group well precipitation test can be developed before the foundation pit is excavated, the following problems exist: 1) Because the underground water leakage in the excavation process cannot be completely and truly simulated in the non-excavation state, the situation that the precipitation test is not leaked and the leakage occurs in the excavation process frequently occurs; 2) Even if a leak is found, it is only known that the leak occurs, and the specific leak joints and leak paths are not clear because groundwater can permeate over long distances; When leakage is found, the prior art can perform leakage blocking through grouting, but the leakage blocking effect needs to be confirmed through a water pumping test again, the result can be known only after 2-3 days, and the result can not be obtained in the same day. Disclosure of Invention The invention designs a detection method for a leakage path of underground water of a foundation pit and a detection method for a repair effect, which are used for quickly finding leakage points of a joint of a diaphragm wall and visually judging a leakage blocking effect by bidirectional accurate positioning of external leakage and internal leakage of the foundation pit by utilizing a pre-buried inclinometer technology. The technical scheme of the invention is as follows: A method for detecting the leakage path of foundation pit groundwater and the repairing effect, S1, detecting an out-pit leakage path; s2, installing a leakage path detection system; s3, confirming a seepage path in the pit; S4, performing leakage repair, repeating the step S1 to perform repair effect detection, and repeating the step S2-S4 if the leakage detection result is not qualified, until the leakage detection result is qualified. In the foundation pit excavation stage, different color water bodies are injected into a plurality of preset inclinometer pipes, the colors of the groundwater in the dewatering well outside the pit are observed after a plurality of times for judging whether leakage occurs, the inclinometer pipes are positioned in a foundation pit underground wall joint, and the pipe body of each inclinometer pipe is provided with holes; When the water color of the dewatering well near the inclinometer pipe is unchanged, the joint at the inclinometer pipe is free from an out-of-pit seepage path, and S2-S4 are not needed; when the water in the dewatering well near the in