High-precision foundation pit support leakage potential measurement system and method

Abstract

The invention discloses a high-precision foundation pit support leakage potential measurement system and method, an electrode matrix, an electric field establishment module, a reference electrode, a multi-channel electric signal parallel measurement device and a data processing terminal are arranged in a foundation pit, and the outer side of a non-polarized electrode of the electrode matrix is filled with bentonite slurry; the bentonite slurry can infiltrate the contact part of the non-polarized electrode and a foundation pit soil body so as to change the property of the soil body, so that the contact potential of the electrode matrix and the soil body is controlled, the measurement error is reduced, meanwhile, an ion concentration meter and a temperature sensor are arranged in the non-polarized electrode and the reference electrode of the electrode matrix respectively, and the measurement accuracy is improved. The data processing terminal can correct the potential difference according to the electrode temperature and the ion concentration of the non-polarized electrode and the reference electrode temperature and the reference ion concentration of the reference electrode to calibrate the electrode range caused by the temperature and the ion concentration, so that the real potential difference of the foundation pit is obtained, and the measurement precision is effectively improved. And the accuracy and reliability of a foundation pit leakage detection result are improved.

Description

Technical Field

[0001] The invention relates to the technical field of foundation pit retaining, and in particular to high-precision foundation pit retaining leakage detection. Background Art

[0002] As the construction scale of underground projects develops towards deeper and larger dimensions, the risks faced by foundation pit construction are also gradually increasing. Among them, leakage of foundation pit retaining structures is a risk that occurs more frequently, seriously threatening the construction safety of the foundation pit and even causing the collapse of the retaining structure. The existing method for detecting foundation pit leakage is the electrical method, which determines the leakage point by establishing an artificial current field and using non-polarized electrodes to detect potential abnormalities.

[0003] A Chinese patent with announcement number CN 218240441 U discloses a device for detecting leakage hazards of foundation pit retaining structures, comprising: at least two special protective pipes, the special protective pipes are arranged on the periphery of the ground wall structure; an electric field establishment device, the electric field establishment device establishes a stable electric field in the foundation pit, the electric field establishment device comprises: a first power supply electrode; a second power supply electrode; a power supply source, the power supply source comprises: a power output end, the power output end is connected to the first power supply electrode and the second power supply electrode; a potential measuring device, the potential measuring device comprises: a potential gradient observation control analyzer; at least two potential gradient measurement lines, one end of the potential gradient measurement line is connected to the potential gradient observation control analyzer, and the other end is placed at the bottom of the special protective pipe; at least two potential measurement sensors, the potential measurement sensors are arranged in series in the special protective pipe through the potential gradient measurement lines.

[0004] However, the existing method of using non-polarized electrodes for foundation pit leakage detection requires that the non-polarized electrodes be directly buried in the earth's soil and fully contact the earth to sense and transmit the earth's electric field information. The acquisition accuracy has a great impact on the detection results. However, the foundation pit site environment is complex. The foundation pit temperature, the potential difference of the electrode pair itself (i.e., the extreme difference), the contact potential between the electrode and the soil, and the stray current will cause serious interference to the measured potential data, which will bring difficulties to the post-processing and inversion interpretation of the potential data, resulting in large errors in the measurement accuracy and unreliable foundation pit seepage detection results.

[0005] Therefore, how to effectively improve the accuracy of potential measurement and the reliability of foundation pit leakage detection results has become an urgent problem to be solved in this field. Summary of the invention

[0006] In view of the defects of the prior art, the purpose of the present invention is to provide a high-precision foundation pit retaining wall leakage potential measurement system and method, so as to improve the potential measurement accuracy and foundation pit leakage detection results.

[0007] In order to achieve the above-mentioned purpose, the high-precision foundation pit enclosure leakage potential measurement system provided by the present invention is used to cooperate with the enclosure structure of the foundation pit, including an electrode matrix and an electric field establishment module, and also includes a reference electrode, a multi-channel electrical signal parallel measurement device and a data processing terminal.

[0008] The electrode matrix is ​​arranged inside the enclosure structure, and is composed of a plurality of non-polarized electrode arrays distributed and connected in series. The outside of the non-polarized electrode is filled with bentonite slurry, and an ion concentration meter and a temperature sensor are arranged in the non-polarized electrode. The bentonite slurry is configured to be released to infiltrate the contact portion between the non-polarized electrode and the foundation pit soil.

[0009] The electric field establishment module is configured to emit current signals along different depths of the foundation pit to establish a current field in the foundation pit.

[0010] The reference electrode is arranged inside the enclosure structure and away from the electrode matrix and the electric field establishment module, and a reference ion concentration meter and a reference temperature sensor are arranged in the reference electrode.

[0011] The multi-channel electrical signal parallel measurement device is configured to synchronously collect the potential difference between all non-polarizable electrodes and the reference electrode in the electrode matrix,

[0012] The data processing terminal can control the release state of the bentonite slurry in the electrode matrix, obtain the electrode temperature and ion concentration of all non-polarizable electrodes in the electrode matrix and the reference electrode temperature and reference ion concentration of the reference electrode, and correct the potential difference collected by the multi-channel electrical signal parallel measurement device to generate the real potential difference of the foundation pit and determine the leakage abnormal points of the surrounding structure.

[0013] Furthermore, the electrode matrix is ​​arranged in parallel with the enclosure structure, and a plurality of non-polarized electrodes are arranged equidistantly in a mesh at a spacing of 0.5-2 m, and the spacing between the first row of non-polarized electrodes and the enclosure structure is 0.5 m.

[0014] Furthermore, the non-polarizable electrode is composed of a Pb-PbCl2 non-polarizable electrode, and the ion concentration meter is composed of a lead ion concentration meter.

[0015] Furthermore, the non-polarizable electrode comprises a shell, the bentonite slurry is distributed in the upper area outside the shell, and an electric gate valve for connecting and cooperating with the data processing terminal is provided at the bottom of the bentonite slurry.

[0016] Furthermore, the depth at which the non-polarizable electrode is inserted into the foundation pit soil is matched with the height at which the electric gate valve is arranged on the shell.

[0017] Furthermore, the proportion of bentonite in the bentonite slurry is 5%-8%.

[0018] Furthermore, an electrode launching shaft is provided outside the enclosure structure, the launching electrode is built into the electrode launching shaft, the distance between the electrode launching shaft and the enclosure structure is 3-10m, and the depth of the electrode launching shaft is greater than the foundation pit depth of 5m.

[0019] Furthermore, the electric field establishing module includes a digitally controlled current transmitting device, a transmitting electrode and a receiving electrode, the transmitting electrode is arranged on the outside of the enclosure structure, and the receiving electrode is arranged on the inside of the enclosure structure and away from the electrode matrix, and the digitally controlled current transmitting device is configured to control the transmitting electrode to transmit current signals along different depths of the foundation pit so that the receiving electrode can receive the current signals.

[0020] In order to achieve the above-mentioned object, the present invention provides a high-precision foundation pit enclosure leakage potential measurement method, based on the high-precision foundation pit enclosure leakage potential measurement system, the measurement method comprises:

[0021] Measurement preparation: lay out the electric field establishment module in the foundation pit, and lay out the electrode matrix and reference electrode inside the enclosure structure.

[0022] On-site measurement, the data processing terminal controls the release state of the bentonite slurry in the electrode matrix to wet the contact part between the non-polarized electrodes of the electrode matrix and the foundation pit soil. The electric field establishment module transmits current signals along different depths of the foundation pit to establish a current field in the foundation pit.

[0023] At the same time, the multi-channel electrical signal parallel measurement device synchronously collects the potential difference between all non-polarized electrodes and the reference electrode in the electrode matrix, and the data processing terminal obtains the electrode temperature and ion concentration of all non-polarized electrodes in the electrode matrix and the reference electrode temperature and reference ion concentration of the reference electrode in real time.

[0024] Data processing: The data processing terminal receives the potential difference collected by the multi-channel electrical signal parallel measurement device and performs correction processing to obtain the real potential difference of the foundation pit and determine the leakage abnormal point of the enclosure structure. The real potential difference E is

[0025]

[0026] Where:

[0027] R is the gas constant of the gas in the foundation pit,

[0028] T i is the electrode temperature of different non-polarizable electrodes in the electrode matrix,

[0029] M i is the ion concentration of different non-polarizable electrodes in the electrode matrix,

[0030] n is the valence of the metal cations of the different non-polarizable electrodes in the electrode matrix,

[0031] F is Faraday's constant,

[0032] T n is the reference electrode temperature of the reference electrode,

[0033] M n is the reference ion concentration of the reference electrode.

[0034] Furthermore, the electric field establishing modules are lifted equidistantly from the bottom to the top of the foundation pit at intervals of 0.5-2 m, and emit current signals at corresponding depths of the foundation pit.

[0035] The high-precision foundation pit retaining leakage potential measurement system and method provided by the present invention respectively arrange an electrode matrix, an electric field establishment module, a reference electrode, a multi-channel electrical signal parallel measurement device and a data processing terminal in the foundation pit, and fill the outside of the non-polarized electrode of the electrode matrix with bentonite slurry, so that the bentonite slurry can infiltrate the contact part between the non-polarized electrode and the foundation pit soil. Since the contact potential between the electrode matrix and the soil is related to the ion composition and concentration of the soil, the bentonite slurry can effectively change the soil properties, thereby controlling the contact potential between the electrode matrix and the soil, reducing the measurement error and improving the measurement accuracy.

[0036] At the same time, the non-polarizable electrode and the reference electrode of the electrode matrix are respectively provided with an ion concentration meter and a temperature sensor, so that the data processing terminal can correct the potential difference between the non-polarizable electrode and the reference electrode according to the electrode temperature and ion concentration of the non-polarizable electrode, and the reference electrode temperature and reference ion concentration of the reference electrode, so as to calibrate the electrode extreme difference caused by temperature and ion concentration, thereby obtaining the true potential difference after correction of the foundation pit, so as to effectively improve the measurement accuracy and improve the accuracy and reliability of the foundation pit leakage detection results. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0038] Figure 1 The overall schematic diagram of the high-precision foundation pit enclosure leakage potential measurement system provided by the present invention;

[0039] Figure 2 It is a schematic diagram of the structure of the non-polarizable electrode in the present invention. Description of the drawings:

[0041] 100. Electrode matrix; 110. Non-polarizable electrode; 111. Housing; 112. Insulation cap; 113. Cork; 114. Electrolyte; 115. Lead wire; 116. Copper wire; 117. Bentonite slurry; 118. Electric valve; 119. Ion concentration meter; 120. Temperature sensor; 121. Battery;

[0042] 200. Electric field establishment module; 210. Digitally controlled current transmitting device; 220. Transmitting electrode; 230. Receiving electrode; 240. Electrode transmitting well;

[0043] 300. reference electrode; 310. reference ion concentration meter; 320. temperature sensor;

[0044] 400. Multi-channel electrical signal parallel measurement equipment;

[0045] 500. Data processing terminal;

[0046] 600. Foundation pit; 610. Retaining structure; 620. Soil. DETAILED DESCRIPTION

[0047] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below with reference to specific diagrams.

[0048] See also Figure 1 , which shows an example of the high-precision foundation pit retaining leakage potential measurement system provided by the present invention.

[0049] As can be seen from the figure, the high-precision foundation pit retaining leakage potential measurement system of this example is used to cooperate with the retaining structure 610 of the foundation pit 600, and mainly includes an electrode matrix 100, an electric field establishment module 200, a reference electrode 300, a multi-channel electrical signal parallel measurement device 400 and a data processing terminal 500.

[0050] The electrode matrix 100 is arranged on the inner side of the enclosure structure 610, and is composed of a plurality of non-polarized electrodes 110 distributed in an array and connected in series. The outer side of the non-polarized electrode 110 is filled with bentonite slurry, so that the bentonite slurry can infiltrate the contact portion between the non-polarized electrode 110 and the foundation pit soil 620, so as to effectively control the contact potential between the electrode matrix 600 and the soil 620, reduce the measurement error, and improve the measurement accuracy. The non-polarized electrode 110 is also provided with an ion concentration meter and a temperature sensor.

[0051] The electric field establishing module 200 includes a digitally controlled current transmitting device 210 , a transmitting electrode 220 and a receiving electrode 230 , and can transmit current signals along different depths of the foundation pit 600 , thereby establishing an electric field in the foundation pit 600 .

[0052] The reference electrode 300 is arranged inside the enclosure structure 610 and away from the electrode matrix 100 and the receiving electrode 230 . The reference electrode 300 is provided with a reference ion concentration meter and a reference temperature sensor to provide reference correction data for the real potential difference of the foundation pit 600 .

[0053] The multi-channel electrical signal parallel measurement device 400 is configured to synchronously collect the potential differences between all the non-polarizable electrodes 110 and the reference electrode 300 in the electrode matrix 100 .

[0054] The data processing terminal 500 can control the release state of the bentonite slurry in the electrode matrix 100, obtain the electrode temperature and ion concentration of all non-polarizable electrodes 110 in the electrode matrix 100 and the reference electrode temperature and reference ion concentration of the reference electrode 300, and correct the potential difference collected by the multi-channel electrical signal parallel measurement device 400 to generate the real potential difference of the foundation pit 600, and determine the leakage abnormal point of the retaining structure 610, so as to calibrate the electrode extreme difference caused by temperature and ion concentration, control the contact potential between the non-polarizable electrode 110 and the soil 620, and improve the measurement accuracy and detection precision of the foundation pit retaining leakage potential.

[0055] Among them, the electrode matrix 100 is arranged on the inner side of the enclosure structure 610 and parallel to the enclosure structure 610. The plurality of non-polarized electrodes 110 are preferably arranged equidistantly in a grid with a spacing of 0.5-2m, so that the non-polarized electrodes 110 will not interfere with each other, and the distribution spacing can accurately reflect the potential difference distribution of the enclosure structure 610. Among them, the first row of non-polarized electrodes 110 matched with the enclosure structure 610 is preferably configured to have a spacing of 0.5m with the enclosure structure 610 to ensure that the enclosure structure does not interfere with the non-polarized electrodes 110, thereby improving the measurement accuracy.

[0056] Furthermore, several non-polarizable electrodes 110 are connected in series through cables and are respectively connected to the multi-channel electrical signal parallel measurement device 400, so that the multi-channel electrical signal parallel measurement device 400 can synchronously obtain the potential difference between each non-polarizable electrode 110 and the reference electrode 300, so as to quickly detect the potential data of all non-polarizable electrodes 110 and avoid the influence of random factors such as stray current on the measurement of potential difference.

[0057] Here, the non-polarizable electrode 110 is preferably composed of a Pb-PbCl2 non-polarizable electrode, which has a very small range and a long stabilization time, and can effectively ensure the accuracy of the measurement results.

[0058] Combination Figure 2Specifically, the non-polarizable electrode 110 includes a shell 111, an insulating cap 112 and a cork 113 are respectively provided at both ends of the shell 111, the shell 111 is filled with an electrolyte 114, and the electrolyte 114 is preferably composed of lead chloride powder. A lead wire 115 is also provided in the shell 111, and the lead wire 115 extends to the end of the insulating cap 112 and is connected to a copper wire 116 placed outside the insulating cap 112, so that the non-polarizable electrode 110 is connected to the cable through the copper wire 116, thereby connecting to the multi-channel electrical signal parallel measurement device 400.

[0059] In order to correct the potential difference, a bentonite slurry 117 is provided in the upper area outside the shell 111 of the non-polarizable electrode 110, and an electric valve 118 is provided at the bottom of the bentonite slurry 117. The electric valve 118 is connected to the data processing terminal 500, so that before the measurement starts, the data processing terminal 500 can control the working state of the electric valve 118. When the electric valve 118 is opened, the bentonite slurry 117 can be released to allow the bentonite slurry 117 to infiltrate the contact part between the shell 111 of the non-polarizable electrode 110 and the soil 620 of the foundation pit 600, thereby changing the properties of the soil 620.

[0060] Preferably, the data processing terminal 500 controls the electric valve 118 to open for 10 seconds to ensure that the bentonite slurry 117 can fully infiltrate the contact portion between the shell 111 of the non-polarizable electrode 110 and the soil 620 of the foundation pit 600, effectively changing the properties of the soil 620.

[0061] Since the contact potential between the non-polarizable electrode 110 and the soil 620 is related to the ion composition and concentration of the soil 620, changing the properties of the soil 620 through the bentonite slurry 117 can effectively control the contact potential between the non-polarizable electrode 110 and the soil 620 to reduce the measurement error of the potential difference.

[0062] Furthermore, the depth of the non-polarizable electrode 110 inserted into the foundation pit soil 620 is adapted to the height at which the electric gate valve 118 is set on the outer shell 111, so that when the non-polarizable electrode 110 is inserted into the soil 620, the electric gate valve 118 is placed above the soil 620. At this time, the electric gate valve 118 is opened, and the bentonite slurry 117 can be quickly released to effectively infiltrate the contact part between the outer shell 111 and the soil 620, thereby quickly changing the properties of the soil 620 and preventing the potential difference measurement from being affected.

[0063] Preferably, the proportion of bentonite in the bentonite slurry 117 is 5% to 8%, which can be adaptively adjusted according to specific applications to effectively change the properties of the soil 620 and control the contact potential between the non-polarizable electrode 110 and the soil 620 .

[0064] Furthermore, an ion concentration meter 119 and a temperature sensor 120 are also provided in the housing 111 of the non-polarizable electrode 110. The ion concentration meter 119 is composed of a lead ion concentration meter to effectively detect the lead ion concentration in the Pb-PbCl2 non-polarizable electrode. Correspondingly, the temperature sensor 120 can detect the electrode temperature of the non-polarizable electrode 110 in real time. The ion concentration meter 119 and the temperature sensor 120 are respectively connected to the data processing terminal 500, and can transmit the detected ion concentration and electrode temperature to the data processing terminal 500 in real time, so as to provide correction data for the calibration of the potential difference, so as to improve the measurement accuracy.

[0065] In coordination therewith, a battery 121 is also provided on the top of the bentonite slurry 117 of the non-polarizable electrode 110, so that the battery 121 can provide driving power to the electric valve 118, the ion concentration meter 119 and the temperature sensor 120 respectively, to ensure that the electric valve 118, the ion concentration meter 119 and the temperature sensor 120 can work stably.

[0066] The array of non-polarizable electrodes 110 thus formed is distributed to form an electrode matrix 100, and the contact potential between the soil 620 and the non-polarizable electrode 110 is effectively controlled through the cooperation of bentonite slurry 117, electric valve 118, ion concentration meter 119 and temperature sensor 120, and the ion concentration and electrode temperature of the non-polarizable electrode 110 are transmitted to the data processing terminal 500 in real time, providing correction data for the calibration of the potential difference, so as to improve the measurement accuracy.

[0067] Combination Figure 1 Furthermore, the electric field establishing module 200 includes a digitally controlled current transmitting device 210, a transmitting electrode 220 and a receiving electrode 230. The digitally controlled current transmitting device 210 can control the transmitting electrode 220 to transmit current signals along different depths of the foundation pit 600 so that the receiving electrode 230 can receive the current signals.

[0068] Specifically, the transmitting electrode 220 is arranged outside the enclosure structure 610 and is connected to the multi-channel electrical signal parallel measurement device 400 through a cable. An electrode transmitting well 240 is provided outside the enclosure structure 610. The transmitting electrode 220 is built into the electrode transmitting well 240, and the distance between the electrode transmitting well 240 and the enclosure structure 610 is preferably configured to be 3-10m. Controlling the distance between the electrode transmitting well 240 and the enclosure structure 610 within an appropriate range can effectively control the influence range of the current field, thereby controlling the measurement effect.

[0069] Furthermore, the depth of the electrode transmitting well 240 is greater than 5 m of the depth of the foundation pit 600, so that the transmitting electrode 220 can transmit current signals at multiple depths of the foundation pit 600, so that the electrode matrix 100 can provide multiple corresponding potential difference data, thereby improving the measurement accuracy.

[0070] At the same time, a sieve tube is provided in the electrode transmitting well 240, and plum blossom holes are arranged on the outside of the sieve tube. The outside of the sieve tube is covered with a filter membrane and filled with a coarse sand layer, so that the plum blossom holes, the filter membrane and the coarse sand layer can cooperate to protect the transmitting electrode 220 from the influence of the external environment and prevent impurities from entering the transmitting electrode 220. At the same time, it can also improve the distribution uniformity and transmission stability of the current signal emitted by the transmitting electrode 220.

[0071] In coordination therewith, the receiving electrode 230 is arranged on the inner side of the enclosure structure 610 and away from the electrode matrix 100 to prevent the receiving electrode 230 from interfering with the electrode matrix 100. The receiving electrode 230 can be composed of polarized electrodes such as copper electrodes and steel electrodes, and is connected to the multi-channel electrical signal parallel measurement device 400 through a cable, so that the receiving electrode 230 can receive the current signal emitted by the transmitting electrode 220.

[0072] Furthermore, the digitally controlled current transmitting device 210 is preferably composed of a programmable high-voltage direct current transmitter, so that the digitally controlled current transmitting device 210 can be programmed to transmit a voltage of any waveform, and the adjustable voltage range is preferably configured to be 0 to 500 V. The digitally controlled current transmitting device 210 is bidirectionally connected to the multi-channel electrical signal parallel measuring device 400, and is configured to be able to program the voltage according to the instructions of the data processing terminal 500, and transmit the voltage to the transmitting electrode 220 through the multi-channel electrical signal parallel measuring device 400, so that the transmitting electrode 220 transmits the current signal, and the receiving electrode 230 receives the current signal, thereby establishing a current field in the foundation pit.

[0073] Correspondingly, the numerically controlled current transmitting device 210 can also control the transmitting electrode 220 to be lifted equidistantly from the bottom to the top of the foundation pit 600 at a spacing of 0.5-2m, and transmit current signals at corresponding depths of the foundation pit 600 to form an equidistant current field, so that the electrode matrix 100 can provide potential difference data corresponding to equidistant depths of the foundation pit 600, thereby determining the depth position and horizontal position of the abnormal leakage point in the retaining structure 610.

[0074] The electric field establishment module 200 thus constructed can establish a current field in the foundation pit 600 through the cooperation between the digitally controlled current transmitting device 210, the transmitting electrode 220 and the receiving electrode 230.

[0075] Combination Figure 1 In coordination therewith, the reference electrode 300 is arranged on the inner side of the enclosure structure 610 and away from the electrode matrix 100 and the receiving electrode 230 to prevent the reference electrode 300, the electrode matrix 100 and the receiving electrode 230 from interfering with each other, and is connected to the multi-channel electrical signal parallel measuring device 400 via a cable, so that the multi-channel electrical signal parallel measuring device 400 can obtain the potential data of the reference electrode 300, and measure the potential difference between the non-polarized electrodes 110 at different distribution positions in the electrode matrix 100 and the reference electrode 300.

[0076] Furthermore, combined with Figure 2 The reference electrode 300 is also composed of a non-polarized electrode, and is provided with a reference ion concentration meter 310 and a reference temperature sensor 320. The reference ion concentration meter 310 and the reference temperature sensor 320 are respectively connected to the data processing terminal 500, and can detect the reference electrode temperature and reference ion concentration of the reference electrode 300, and transmit the measured values ​​to the data processing terminal 500 in real time, providing reference data for the calibration of the potential difference.

[0077] The reference electrode 300 thus constructed can cooperate with the electrode matrix 100. The electrode matrix 100 is arranged between the transmitting electrode 220 and the receiving electrode 230. The electrode matrix 100 can reflect the change of the current signal. The reference electrode 300 is far away from the electrode matrix 100. The multi-channel electrical signal parallel measurement device 400 can reflect the abnormal leakage of the enclosure structure 610 by measuring the potential difference between the non-polarized electrodes 110 at different distribution positions in the electrode matrix 100 and the reference electrode 300.

[0078] Specifically, the multi-channel electrical signal parallel measurement device 400 is composed of a potential measurement device, and is configured to synchronously measure all non-polarized electrodes 110M1, M2, M3 ... M in the electrode matrix 100. i The potential difference between the electrode and the reference electrode N is measured and the potential difference is transmitted to the data processing terminal 500 in real time so that the data processing terminal 500 can perform potential difference correction processing.

[0079] Here, by synchronously and parallelly measuring the potential differences of all the non-polarizable electrodes 110, all the potential difference data can be detected within 1 second, so as to effectively avoid the influence of random factors such as stray current and improve the measurement accuracy.

[0080] In coordination therewith, the data processing terminal 500 is configured to control the working state of the electric valve 118 before the measurement starts, so as to control the release state of the bentonite slurry 117 , thereby changing the properties of the soil 620 and reducing the contact potential between the electrode matrix 100 and the soil 620 .

[0081] Furthermore, the data processing terminal 500 can also control the transmitting electrode 220 to transmit current signals through the digitally controlled current transmitting device 210 to establish a current field in the foundation pit 600, and obtain in real time the potential difference between all non-polarized electrodes 110 and the reference electrode in the electrode matrix 100, the electrode temperature and ion concentration of all non-polarized electrodes 110 in the electrode matrix 100, and the reference electrode temperature and reference ion concentration of the reference electrode 300, and can process these data, correct the potential difference, and generate the real potential difference of the foundation pit 600, thereby improving the measurement accuracy and the detection accuracy of foundation pit enclosure leakage.

[0082] Specifically, the real potential difference E of the foundation pit 600 is

[0083]

[0084] Where:

[0085] R is the gas constant of the gas in the pit 600, and its value is about 8.314;

[0086] T i is the electrode temperature of different non-polarized electrodes 110 in the electrode matrix 100,

[0087] M i is the ion concentration of different non-polarizable electrodes 110 in the electrode matrix 100,

[0088] n is the valence of the metal cations of the different non-polarizable electrodes 110 in the electrode matrix 100. The non-polarizable electrodes 110 are composed of Pb-PbCl2 non-polarizable electrodes. The valence of the metal cations is P b =2,

[0089] F is Faraday's constant, which is approximately 96485;

[0090] T n is the reference electrode temperature of the reference electrode 300,

[0091] M n is the reference ion concentration of the reference electrode 300 .

[0092] As shown in the above formula, the data processing terminal 500 converts the potential difference E between the non-polarized electrode 110 and the reference electrode 300 in the electrode matrix 100 measured by the multi-channel electrical signal parallel measurement device 400 into: i Subtracting the error effects of electrode temperature and ion concentration on the potential difference can effectively calibrate the electrode extreme difference caused by temperature and ion concentration, thereby correcting the potential difference, obtaining the true potential difference E, and effectively improving the measurement accuracy.

[0093] Furthermore, the data processing terminal 500 draws a two-dimensional contour map and a three-dimensional contour surface map of the potential of the foundation pit 600 at different depths of the transmitting electrode 220 according to the distribution positions of all non-polarized electrodes 110 in the electrode matrix 100, the true potential difference E, and the depth position of the transmitting electrode 220, so as to determine the position of the abnormal leakage point of the enclosure structure 610.

[0094] Thus, the high-precision foundation pit enclosure leakage potential measurement system provided by the present invention is formed.

[0095] The present invention also provides a high-precision foundation pit enclosure leakage potential measurement method, based on the high-precision foundation pit enclosure leakage potential measurement system constructed by the above scheme, the measurement method comprises:

[0096] Measurement preparation: an electric field establishment module 200 is arranged in the foundation pit 600 , and an electrode matrix 100 and a reference electrode 300 are arranged inside the enclosure structure 610 .

[0097] The electrode matrix 100 is arranged inside the enclosure structure 610 and parallel to the enclosure structure 610. The plurality of non-polarizable electrodes 110 are preferably arranged equidistantly in a grid with a spacing of 0.5-2 m, and are connected in series with the multi-channel electrical signal parallel measurement device 400 through cables. The spacing between the first row of non-polarizable electrodes 110 and the enclosure structure 610 is preferably configured to be 0.5 m.

[0098] The non-polarizable electrode 110 is a Pb-PbCl2 non-polarizable electrode, and the depth of the non-polarizable electrode 110 inserted into the foundation pit soil 620 matches the height of the electric gate valve 118 set on the shell 111 to arrange the electrode matrix 100.

[0099] Next, the transmitting electrode 220 of the electric field establishment module 200 is set outside the enclosure structure 610, built into the electrode transmitting well 240 and connected to the multi-channel electrical signal parallel measurement device 400 through a cable. The distance between the electrode transmitting well 240 and the enclosure structure 610 is preferably configured to be 3-10m, the depth of the electrode transmitting well 240 is greater than the depth of the foundation pit 600 by 5m, and a screen pipe is arranged in the electrode transmitting well 240, and plum blossom holes are arranged on the outside of the screen pipe. The outside of the screen pipe is covered with a filter membrane and filled with a coarse sand layer.

[0100] Meanwhile, the receiving electrode 230 is arranged inside the enclosure structure 610 and away from the electrode matrix 100 , and is connected to the multi-channel electrical signal parallel measurement device 400 via a cable.

[0101] Accordingly, the digitally controlled current transmitting device 210 is preferably composed of a programmable high-voltage direct current transmitter, and is bidirectionally connected to the multi-channel electrical signal parallel measuring device 400 to deploy the electric field establishing module 200 .

[0102] Next, the reference electrode 300 is disposed inside the enclosure 610 and away from the electrode matrix 100 and the receiving electrode 230 , is composed of a non-polarized electrode, and is connected to the multi-channel electrical signal parallel measurement device 400 via a cable to deploy the reference electrode 300 .

[0103] On-site measurement: First, before the measurement begins, the data processing terminal 500 controls the release state of the bentonite slurry 117 in the electrode matrix 100 to infiltrate the contact portion between the non-polarizable electrodes 110 of the electrode matrix 100 and the foundation pit soil 620 .

[0104] The data processing terminal 500 controls the electric valve 118 to open for 10 seconds, so that the bentonite slurry 117 can fully infiltrate the contact part between the shell 111 of the non-polarizable electrode 110 and the soil 620 of the foundation pit 600, effectively changing the properties of the soil 620, thereby controlling the contact potential between the non-polarizable electrode 110 and the soil 620 to reduce the measurement error of the potential difference.

[0105] Next, the digitally controlled current transmitting device 210 controls the transmitting electrode 220 to transmit the current signal along different depths of the foundation pit 600 , so that the receiving electrode 230 can receive the current signal.

[0106] The data processing terminal 500 issues instructions to the digitally controlled current transmitting device 210, so that the digitally controlled current transmitting device 210 programs the voltage according to the instructions, and transmits the voltage to the transmitting electrode 220 through the multi-channel electrical signal parallel measurement device 400, so that the transmitting electrode 220 transmits the current signal and the receiving electrode 230 receives the current signal, thereby establishing a current field in the foundation pit.

[0107] Furthermore, the numerically controlled current transmitting device 210 controls the transmitting electrode 220 to be lifted equidistantly from the bottom to the top of the foundation pit 600 at intervals of 0.5-2 m, and transmits current signals at corresponding depths of the foundation pit 600 to form an equidistant current field to detect the potential of the foundation pit at different depths.

[0108] At the same time, the multi-channel electrical signal parallel measurement device 400 synchronously collects the non-polarized electrodes 110M1, M2, M3...M in the electrode matrix 100 i The potential difference between the electrode 300N and the reference electrode 300N is transmitted to the data processing terminal 500 in real time so that the data processing terminal 500 can perform potential difference correction processing.

[0109] At the same time, the data processing terminal 500 acquires in real time the electrode temperature and ion concentration of all the non-polarizable electrodes 110 in the electrode matrix 100 and the reference electrode temperature and reference ion concentration of the reference electrode 300 .

[0110] Data processing: The data processing terminal 500 receives the potential difference collected by the multi-channel electrical signal parallel measurement device and performs correction processing to obtain the real potential difference of the foundation pit. The real potential difference E is

[0111]

[0112] Where:

[0113] R is the gas constant of the gas in the pit 600, and its value is about 8.314;

[0114] T i is the electrode temperature of different non-polarized electrodes 110 in the electrode matrix 100,

[0115] M i is the ion concentration of different non-polarizable electrodes 110 in the electrode matrix 100,

[0116] n is the valence of the metal cations of the different non-polarizable electrodes 110 in the electrode matrix 100. The non-polarizable electrodes 110 are composed of Pb-PbCl2 non-polarizable electrodes. The valence of the metal cations is P b =2,

[0117] F is Faraday's constant, which is approximately 96485;

[0118] T n is the reference electrode temperature of the reference electrode 300,

[0119] M n is the reference ion concentration of the reference electrode 300 .

[0120] As a result, the data processing terminal 500 generates the potential difference E i Subtracting the error effects of electrode temperature and ion concentration on the potential difference can effectively calibrate the electrode extreme difference caused by temperature and ion concentration, thereby correcting the potential difference, obtaining the true potential difference E, and effectively improving the measurement accuracy.

[0121] Furthermore, the data processing terminal 500 determines the leakage abnormal point of the enclosure structure.

[0122] The data processing terminal 500 draws a two-dimensional contour map and a three-dimensional contour surface map of the potential of the foundation pit 600 at different depths of the transmitting electrode 220 according to the distribution positions of all non-polarized electrodes 110 in the electrode matrix 100, the real potential difference E, and the depth position of the transmitting electrode 220, so as to determine the position of the leakage abnormal point of the enclosure structure 610.

[0123] This completes the measurement and detection of the leakage potential of the foundation pit retaining wall.

[0124] The high-precision foundation pit enclosure leakage potential measurement system and method provided by the present invention can calibrate the electrode extreme difference caused by temperature and ion concentration, control the contact potential between the electrode and the soil, and the random error through the cooperation of the electrode matrix 100, the electric field establishment module 200, the reference electrode 300, the multi-channel electrical signal parallel measurement device 400 and the data processing terminal 500, thereby effectively improving the foundation pit enclosure leakage potential measurement accuracy and detection precision.

[0125] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A high-precision foundation pit enclosure leakage potential measurement system, used to cooperate with the enclosure structure of the foundation pit, including an electrode matrix and an electric field establishment module, characterized in that: It also includes reference electrodes, multi-channel electrical signal parallel measurement equipment and data processing terminals. The electrode matrix is ​​arranged inside the enclosure structure, and is composed of a plurality of non-polarized electrode arrays distributed and connected in series. The outside of the non-polarized electrode is filled with bentonite slurry, and an ion concentration meter and a temperature sensor are arranged in the non-polarized electrode. The bentonite slurry is configured to be released to infiltrate the contact portion between the non-polarized electrode and the foundation pit soil. The electric field establishment module is configured to emit current signals along different depths of the foundation pit to establish a current field in the foundation pit. The reference electrode is arranged inside the enclosure structure and away from the electrode matrix and the electric field establishment module, and a reference ion concentration meter and a reference temperature sensor are arranged in the reference electrode. The multi-channel electrical signal parallel measurement device is configured to synchronously collect the potential difference between all non-polarizable electrodes and the reference electrode in the electrode matrix, The data processing terminal can control the release state of the bentonite slurry in the electrode matrix, obtain the electrode temperature and ion concentration of all non-polarizable electrodes in the electrode matrix and the reference electrode temperature and reference ion concentration of the reference electrode, and correct the potential difference collected by the multi-channel electrical signal parallel measurement device to generate the real potential difference of the foundation pit and determine the leakage abnormal points of the surrounding structure.

2. The high-precision foundation pit protection leakage potential measurement system according to claim 1 is characterized in that: The electrode matrix is ​​arranged in parallel with the enclosure structure, and a plurality of non-polarized electrodes are arranged in a mesh with an interval of 0.5-2 m, and the interval between the first row of non-polarized electrodes and the enclosure structure is 0.5 m.

3. The high-precision foundation pit protection leakage potential measurement system according to claim 2 is characterized in that: The non-polarizable electrode is composed of a Pb-PbCl2 non-polarizable electrode, and the ion concentration meter is composed of a lead ion concentration meter.

4. The high-precision foundation pit protection leakage potential measurement system according to claim 2 is characterized in that: The non-polarizable electrode comprises a shell, the bentonite slurry is distributed in the upper area outside the shell, and an electric gate valve for connecting and cooperating with the data processing terminal is arranged at the bottom of the bentonite slurry.

5. The high-precision foundation pit protection leakage potential measurement system according to claim 4 is characterized in that: The depth of the non-polarizable electrode inserted into the foundation pit soil is matched with the height at which the electric gate valve is arranged on the shell.

6. The high-precision foundation pit protection leakage potential measurement system according to claim 4 is characterized in that: The proportion of bentonite in the bentonite slurry is 5%-8%.

7. The high-precision foundation pit protection leakage potential measurement system according to claim 1 is characterized in that: The electric field establishing module includes a digitally controlled current transmitting device, a transmitting electrode and a receiving electrode. The transmitting electrode is arranged on the outside of the enclosure structure, and the receiving electrode is arranged on the inside of the enclosure structure and away from the electrode matrix. The digitally controlled current transmitting device is configured to control the transmitting electrode to transmit current signals along different depths of the foundation pit so that the receiving electrode can receive the current signals.

8. The high-precision foundation pit protection leakage potential measurement system according to claim 7 is characterized in that: An electrode launching shaft is arranged outside the enclosure structure, and the launching electrode is built in the electrode launching shaft. The distance between the electrode launching shaft and the enclosure structure is 3-10m, and the depth of the electrode launching shaft is greater than the foundation pit depth of 5m.

9. A high-precision method for measuring leakage potential of foundation pit enclosure, characterized in that: Based on the high-precision foundation pit enclosure leakage potential measurement system according to any one of claims 1 to 8, the measurement method comprises: Measurement preparation: lay out the electric field establishment module in the foundation pit, and lay out the electrode matrix and reference electrode inside the enclosure structure. On-site measurement, the data processing terminal controls the release state of the bentonite slurry in the electrode matrix to wet the contact part between the non-polarized electrodes of the electrode matrix and the foundation pit soil. The electric field establishment module transmits current signals along different depths of the foundation pit to establish a current field in the foundation pit. At the same time, the multi-channel electrical signal parallel measurement device synchronously collects the potential difference between all non-polarized electrodes and the reference electrode in the electrode matrix, and the data processing terminal obtains the electrode temperature and ion concentration of all non-polarized electrodes in the electrode matrix and the reference electrode temperature and reference ion concentration of the reference electrode in real time. Data processing: The data processing terminal receives the potential difference collected by the multi-channel electrical signal parallel measurement device and performs correction processing to obtain the real potential difference of the foundation pit and determine the leakage abnormal point of the enclosure structure. The real potential difference E is Where: R is the gas constant of the gas in the foundation pit, T i is the electrode temperature of different non-polarizable electrodes in the electrode matrix, M i is the ion concentration of different non-polarizable electrodes in the electrode matrix, n is the valence of the metal cations of the different non-polarizable electrodes in the electrode matrix, F is Faraday's constant, T n is the reference electrode temperature of the reference electrode, M n is the reference ion concentration of the reference electrode.

10. The high-precision foundation pit enclosure leakage potential measurement method according to claim 9 is characterized in that: The electric field establishing modules are lifted equidistantly from the bottom to the top of the foundation pit at intervals of 0.5-2 m, and emit current signals at corresponding depths of the foundation pit.

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