Monitoring and early warning system of soil-bentonite separating wall

Abstract

The invention relates to the technical field of underground pollution prevention and control construction, and discloses a monitoring and early warning system for a soil-bentonite separating wall. The system comprises a supporting frame, a monitoring device and a data processing module. The supporting frame comprises a first vertical pipe and a second vertical pipe which are located in the separating wall and the side, away from pollutants, of the separating wall correspondingly. The monitoring device comprises a main body monitoring module arranged on the first vertical pipe and an auxiliary monitoring module arranged on the second vertical pipe, and the main body monitoring module is used for collecting strain and pore pressure of each monitoring point position in real time during construction of the isolation wall. The acquisition module is also used for acquiring the resistivity and the water content of each monitoring point inside in real time after the construction of the isolation wall is finished; the auxiliary monitoring module is used for collecting the water level of the outflow side of the separation wall and the TDS value of each monitoring point position in real time after construction of the separation wall is finished; and the data processing module is used for carrying out early warning analysis on the isolation wall according to the collected data. According to the invention, real-time monitoring and timely early warning can be provided for the isolation wall.

Description

Technical Field

[0001] The invention relates to the technical field of underground pollution prevention and control construction, in particular to a monitoring and early warning system for a soil-bentonite isolation wall. Background Art

[0002] When developing mineral resources, tailings ponds can be used to store tailings generated during the smelting process, but tailings ponds will pollute groundwater and the surrounding environment. These sites have a large pollution range and complex pollutant forms. Vertical isolation wall technology is widely used in various underground pollution prevention and control projects due to its strong site adaptability and excellent pollution prevention and control performance. At present, according to the different types of materials, common isolation walls can be divided into soil-bentonite isolation walls, plastic concrete isolation walls, cement-bentonite isolation walls, ordinary concrete isolation walls, geomembrane-bentonite composite isolation walls, artificial frozen soil, steel sheet pile isolation walls, etc. Among them, the soil-bentonite vertical isolation wall is one of the most common types of vertical isolation walls in underground pollution prevention and control projects because of its simple construction and low cost.

[0003] Since pollutants degrade very slowly in their natural state, when the isolation wall is used to block pollutants in situ, it is required to have a long service life. The Chinese invention patent with application number 202111209281.8 discloses the structure and construction method of an activated carbon-modified soil-bentonite vertical anti-pollution isolation wall. By improving the isolation material, the structural strength and pollution isolation performance of the soil-bentonite vertical anti-pollution isolation wall are improved, and its service life is extended. However, in actual engineering applications, the improved soil-bentonite vertical isolation wall still faces the problem of weak corrosion resistance. Long-term exposure to chemical reactions can easily lead to performance degradation. At the same time, it is affected by external factors such as changes in complex geological conditions and construction quality. The service life of the isolation wall obtained by theoretical calculation is still uncertain, which will be directly related to the quality and safety of the surrounding water and soil environment. Therefore, how to monitor the performance status inside the isolation wall in real time and issue timely warnings is an urgent problem to be solved during the service life of the soil-bentonite isolation wall. Summary of the invention

[0004] In order to solve the technical problem in the prior art that it is difficult to provide real-time monitoring and timely warning for a soil-bentonite isolation wall in service, the present invention provides a monitoring and early warning system for a soil-bentonite isolation wall.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] The invention discloses a monitoring and early warning system for a soil-bentonite isolation wall, comprising a support frame, a monitoring device and a data processing module.

[0007] The support frame includes a first vertical pipe and a second vertical pipe; the first vertical pipe is arranged at the central axis position inside the isolation wall, and the second vertical pipe is arranged on the side outside the isolation wall away from the pollution source, i.e., the outflow side; the first vertical pipe and the second vertical pipe are both provided with multiple monitoring points along the depth direction, and the monitoring points on the two vertical pipes correspond one to one and have the same depth.

[0008] The monitoring device includes a main monitoring module arranged on the first vertical pipe and an auxiliary monitoring module arranged on the second vertical pipe; the main monitoring module is used to collect the strain and pore pressure of each internal monitoring point in real time during the construction of the isolation wall, and is also used to collect the resistivity and water content of each internal monitoring point in real time after the construction of the isolation wall is completed; the auxiliary monitoring module is used to collect the water level on the outflow side of the isolation wall and the TDS value of each monitoring point in real time after the construction of the isolation wall is completed.

[0009] The data processing module is used to: a. send the strain and pore pressure of each monitoring point inside the isolation wall during the construction period to an interactive end for feedback to adjust the on-site environmental conditions during the construction period; b. calculate the resistivity change ratio according to the real-time resistivity of each monitoring point, and generate a first warning signal when the resistivity change ratio of any monitoring point exceeds a preset first change ratio threshold; c. correct the wall permeability coefficient according to the real-time moisture content of each monitoring point, and calculate the permeability change ratio, and generate a second warning signal when the permeability change ratio of any monitoring point exceeds a preset second change ratio threshold; d. determine whether the water level on the outflow side of the isolation wall exceeds a preset water level threshold, and if so, generate a third warning signal; e. when the change amplitude of the water level per unit time exceeds the fluctuation range of the background value of the groundwater level of the site, calculate the TDS value change ratio according to the real-time TDS value of each monitoring point, and generate a fourth warning signal when the TDS value change ratio of any monitoring point exceeds the preset third change ratio threshold.

[0010] As a further improvement of the above scheme, the main monitoring module includes several groups of first data acquisition components distributed along the depth direction, and the auxiliary monitoring module includes several groups of second data acquisition components distributed along the depth direction; the number of first data acquisition components and second data acquisition components corresponds one to one and are respectively arranged at corresponding monitoring points; each group of first data acquisition components includes a strain sensor, a pore pressure sensor, a resistivity probe and a TDR sensor, which are respectively used to collect the strain, pore pressure, resistivity and water content of the corresponding monitoring point; each group of second data acquisition components includes a TDS sensor for collecting the TDS value of the corresponding monitoring point; the auxiliary monitoring module also includes a water level monitoring float for collecting the water level on the outflow side of the isolation wall.

[0011] As a further improvement of the above scheme, the calculation formula for calculating the resistivity change ratio according to the real-time resistivity of each monitoring point is:

[0012] N1=|ρ0-ρ i | / ρ0

[0013] Where N1 is the resistivity change ratio of a monitoring point; ρ0 is the resistivity reference value collected by the resistivity probe at the monitoring point within a preset period of time after the completion of the isolation wall construction; ρ i It is the real-time resistivity collected by the resistivity probe at the monitoring point.

[0014] As a further improvement of the above scheme, the calculation formula for correcting the wall permeability coefficient according to the real-time moisture content of each monitoring point is:

[0015]

[0016] Wherein, k is the permeability coefficient; FSI is the free expansion coefficient; e is the porosity; ω is the real-time water content of a monitoring point; A and B are constants fitted according to the bentonite material.

[0017] The calculation formula of permeability coefficient change ratio is:

[0018] M1=|k0-k i | / k0

[0019] Where M1 is the permeability coefficient change ratio of a monitoring point; within a preset period of time after the completion of the isolation wall, the moisture content baseline value collected by the TDR sensor at the monitoring point is ω0; k0 is the wall permeability coefficient corrected by ω0; k i It is the wall permeability coefficient corrected by the real-time moisture content of the monitoring point.

[0020] As a further improvement of the above scheme, the calculation formula for calculating the TDS value change ratio according to the real-time TDS value of each monitoring point is:

[0021] P1=|C0-C i | / C0

[0022] Where, P1 is the TDS value change ratio of a monitoring point; C0 is the TDS value baseline value collected by the TDS sensor at the monitoring point within a preset period of time after the isolation wall is completed; C i It is the real-time TDS value collected by the TDS sensor at the monitoring point.

[0023] As a further improvement of the above scheme, at each monitoring point of the first vertical pipe, the strain sensor, the pore pressure sensor, the resistivity probe and the TDR sensor are distributed circumferentially in the same horizontal plane and are fixedly connected to the outer edge circumference of the first vertical pipe; the second vertical pipe includes an outer pipe and an inner pipe which are coaxially arranged and form a sandwich, the water level monitoring float is arranged in the sandwich, the pipe wall of the outer pipe is evenly provided with a plurality of through holes connected to the sandwich, and the outer side of the outer pipe is wrapped with a geotextile, and at each monitoring point of the second vertical pipe, the TDS sensor is fixedly connected to the geotextile on the outer side of the second vertical pipe.

[0024] As a further improvement of the above scheme, the support frame also includes a transverse tube; the transverse tube is horizontally arranged on the top of the guide walls on both sides of the isolation wall, and the tops of the first vertical tube and the second vertical tube are fixedly connected to the transverse tube, forming a "T"-shaped structure in which the plane is perpendicular to the construction direction of the isolation wall.

[0025] As a further improvement of the above solution, the bottoms of the first vertical tube and the second vertical tube are both anchor ends, and the depth of the anchor ends is greater than the bottom depth of the isolation wall.

[0026] As a further improvement of the above solution, multiple groups of support frames are provided, and the multiple groups of support frames are distributed in sequence along the construction direction of the isolation wall; the number of monitoring devices is the same as the support frames and corresponds one to one.

[0027] As a further improvement of the above scheme, the number of monitoring points in each group of monitoring devices is not less than five, the spacing between adjacent monitoring points increases with increasing depth, and monitoring points are set at the interface between the permeable layer and the impermeable layer in the soil; when the construction direction of the isolation wall is straight, the number of support frames is not less than three groups, and the horizontal spacing between adjacent support frames is not more than 15m; when the construction direction of the isolation wall is non-straight, support frames are set at the turning points, and the support frames at other straight lines still refer to the setting principles of the straight construction direction.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention collects, processes and transmits data reflecting multiple indicators of the isolation wall by setting a support frame capable of installing a monitoring device inside and on the outflow side of the soil-bentonite isolation wall, and using a remotely set data processing module. On the one hand, by monitoring the conditions during the construction of the isolation wall, operators can adjust environmental conditions such as on-site temperature, humidity, wind speed, etc. to meet construction requirements, provide a basis and intervention for the construction of the isolation wall, and ensure construction quality. On the other hand, by evaluating the performance status of the wall during its service and generating early warning signals in a timely manner, it is helpful to timely analyze the causes of the phenomenon and formulate corresponding treatment measures, which has important engineering significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is an architecture diagram of the monitoring and early warning system for the soil-bentonite isolation wall in Example 1 of the present invention.

[0031] Figure 2 This is a schematic cross-sectional view of the monitoring and early warning system for the soil-bentonite isolation wall in Example 1 of the present invention installed underground (the arrow in the figure indicates the flow direction of groundwater).

[0032] Figure 3 for Figure 2 Schematic diagram of the perspective structure of the middle support frame.

[0033] Figure 4 It is a top view installation diagram of the first vertical tube and the first data acquisition assembly in Example 1 of the present invention.

[0034] Figure 5 This is a top view installation diagram of the second vertical tube and the second data acquisition assembly in Example 1 of the present invention.

[0035] Figure 6 It is a top view schematic diagram of the distribution of each support frame when the construction direction of the isolation wall in Example 2 of the present invention is a right-angle turn.

[0036] In the figure: 1. support frame; 11. first vertical pipe; 12. second vertical pipe; 13. horizontal pipe; 2. monitoring device; 21. first data acquisition component; 211. strain sensor; 212. pore pressure sensor; 213. resistivity probe; 214. TDR sensor; 22. second data acquisition component; 221. TDS sensor; 23. water level monitoring float; 3. isolation wall; 4. guide wall; 5. permeable layer; 6. impermeable layer; 7. covering layer; 8. groundwater. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Example 1

[0039] See also Figure 1 to Figure 5 This embodiment provides a monitoring and early warning system for a soil-bentonite isolation wall, including: a support frame 1, a monitoring device 2 and a data processing module.

[0040] The support frame 1 includes a first vertical pipe 11 and a second vertical pipe 12, and may also include a transverse pipe 13; the first vertical pipe 11 is arranged at the central axis position inside the isolation wall 3, and the second vertical pipe 12 is arranged on the side of the isolation wall 3 outside that is away from the pollution source, i.e., the outflow side; the first vertical pipe 11 and the second vertical pipe 12 are both provided with multiple monitoring points along the depth direction, and the monitoring points on the two vertical pipes correspond to each other and have the same depth. The transverse pipe 13 is horizontally arranged on the top of the guide wall 4 on both sides of the isolation wall 3, and the tops of the first vertical pipe 11 and the second vertical pipe 12 are fixedly connected to the transverse pipe 13, and form a "T"-shaped structure in which the plane is perpendicular to the construction direction of the isolation wall 3. The bottoms of the first vertical pipe 11 and the second vertical pipe 12 are both anchor ends, and the depth of the anchor ends is greater than the bottom depth of the isolation wall 3. It should be noted that the support frame 1 can be designed to be narrow to reduce the impact on the fluidity of the isolation wall 3.

[0041] There are multiple groups of support frames 1, and the multiple groups of support frames 1 are distributed in sequence along the construction direction of the isolation wall 3; the number of monitoring devices 2 is the same as the number of support frames 1 and corresponds one to one.

[0042] The construction direction of the isolation wall 3 can be straight, and there are no less than three groups of support frames 1, and the horizontal spacing between adjacent support frames 1 is no more than 15m. The number of monitoring points in each group of monitoring devices 2 is no less than five, and the spacing between adjacent monitoring points increases with the depth, and monitoring points are provided at the interface between the permeable layer 5 and the waterproof layer 6 in the soil. In this embodiment, the construction thickness of the isolation wall 3 is 0.6m, the total length is 50m, the depth of the permeable layer 5 is 19m, and there are a total of seven vertical points. The seven groups of data acquisition modules 211 of each group of monitoring components 21 are respectively arranged at 0m deep, 1m deep, 3m deep, 6m deep, 9m deep, 14m deep, and 19m deep underground, and the horizontal spacing between adjacent support devices 1 is 10m.

[0043] The monitoring device 2 includes a main monitoring module arranged on the first vertical pipe 11 and an auxiliary monitoring module arranged on the second vertical pipe 12 .

[0044] The main monitoring module is used to collect the strain and pore pressure of each internal monitoring point in real time during the construction of the isolation wall 3, and is also used to collect the resistivity and water content of each internal monitoring point in real time after the construction of the isolation wall 3 is completed. Among them, strain refers to the stress change at a certain position inside the isolation wall 3; pore pressure refers to the water pressure at a certain pore inside the isolation wall 3; resistivity refers to the resistance value at a certain position inside the isolation wall 3; water content refers to the volume water content at a certain position inside the isolation wall 3, which can be converted to obtain the water content.

[0045] The auxiliary monitoring module is used to collect the water level on the outflow side of the isolation wall 3 and the TDS value of each monitoring point in real time after the construction of the isolation wall 3 is completed. Among them, TDS (Total Dissolved Solids) refers to the total amount of soluble substances in water, including ions such as calcium, magnesium, sodium, potassium, and some organic and inorganic substances. These substances exist in the water in the form of ions or molecules, affecting the taste, color, turbidity, etc. of the water. Generally, a high TDS may be a sign of the presence of pollutants in the water, which may include heavy metals, organic matter, chemicals, etc.

[0046] In this embodiment, the main monitoring module includes several groups of first data acquisition components 21 distributed along the depth direction, and the auxiliary monitoring module includes several groups of second data acquisition components 22 distributed along the depth direction; the first data acquisition components 21 and the second data acquisition components 22 correspond in number to each other and are respectively arranged at corresponding monitoring points; each group of first data acquisition components 21 includes a strain sensor 211, a pore pressure sensor 212, a resistivity probe 213 and a TDR sensor 214, which are respectively used to collect strain, pore pressure, resistivity and water content of the corresponding monitoring point; each group of second data acquisition components 22 includes a TDS sensor 221, which is used to collect the TDS value of the corresponding monitoring point; the auxiliary monitoring module also includes a water level monitoring float 23, which is used to collect the water level on the outflow side of the isolation wall 3.

[0047] In this embodiment, at each monitoring point of the first vertical pipe 11 , the strain sensor 211 , the pore pressure sensor 212 , the resistivity probe 213 and the TDR sensor 214 are distributed circumferentially in the same horizontal plane and are fixedly connected to the outer circumference of the first vertical pipe 11 .

[0048] The second vertical pipe 12 includes an outer pipe and an inner pipe coaxially arranged to form a sandwich, a water level monitoring float 23 is arranged in the sandwich, a plurality of through holes connected to the sandwich are evenly opened on the wall of the outer pipe, and the outer side of the outer pipe is wrapped with a geotextile, which can prevent larger particles from entering the through holes while allowing water to enter, thereby ensuring that groundwater 8 can enter the sandwich, and the water level monitoring float 23 monitors the water level on the outflow side of the isolation wall 3 in real time. At each monitoring point of the second vertical pipe 12, the TDS sensor 221 is fixedly connected to the geotextile on the outer side of the second vertical pipe 12.

[0049] The data processing module is used to: a. send the strain and pore pressure of each monitoring point inside the isolation wall 3 during the construction to an interactive terminal for feedback to adjust the on-site environmental conditions during the construction, such as adjusting the on-site temperature, humidity, wind speed and other environmental conditions to meet the construction requirements.

[0050] The data processing module is also used for: b. calculating the resistivity change ratio according to the real-time resistivity of each monitoring point, and generating a first warning signal when the resistivity change ratio of any monitoring point exceeds a preset first change ratio threshold. The calculation formula for calculating the resistivity change ratio according to the real-time resistivity of each monitoring point is:

[0051] N1=|ρ0-ρ i | / ρ0

[0052] Wherein, N1 is the resistivity change ratio of a monitoring point; ρ0 is the resistivity reference value collected by the resistivity probe 213 at the monitoring point within a preset period of time after the isolation wall 3 is completed; ρ i It is the real-time resistivity collected by the resistivity probe 213 at the monitoring point.

[0053] The data processing module is also used for: c. correcting the wall permeability coefficient according to the real-time moisture content of each monitoring point, and calculating the permeability coefficient change ratio, and generating a second warning signal when the permeability coefficient change ratio of any monitoring point exceeds a preset second change ratio threshold. The calculation formula for correcting the wall permeability coefficient according to the real-time moisture content of each monitoring point is:

[0054]

[0055] Wherein, k is the permeability coefficient; FSI is the free expansion coefficient; e is the porosity; ω is the real-time moisture content of a monitoring point; A and B are constants fitted according to the bentonite material, which are fitted according to the properties of different bentonite materials indoors, and different materials have different values.

[0056] The calculation formula of permeability coefficient change ratio is:

[0057] M1=|k0-k i | / k0

[0058] Wherein, M1 is the permeability coefficient change ratio of a monitoring point; within a preset period of time after the isolation wall 3 is completed, the moisture content reference value collected by the TDR sensor 214 at the monitoring point is ω0; k0 is the wall permeability coefficient corrected by ω0; k i It is the wall permeability coefficient corrected by the real-time moisture content of the monitoring point.

[0059] In the present invention, the significance of the first and second warning signals is that when the resistivity changes beyond a threshold or the permeability coefficient predicted by the water content changes by an order of magnitude, they can be used as the main basis for judging whether the isolation wall 3 is broken through.

[0060] The data processing module is also used for: d. judging whether the water level on the outflow side of the isolation wall 3 exceeds a preset water level threshold, and if so, generating a third warning signal.

[0061] The data processing module is also used for: e. When the change range of the water level per unit time exceeds the fluctuation range of the groundwater level background value of the site, the TDS value change ratio is calculated according to the real-time TDS value of each monitoring point, and when the TDS value change ratio of any monitoring point exceeds the preset third change ratio threshold, a fourth warning signal is generated. Among them, the calculation formula for calculating the TDS value change ratio according to the real-time TDS value of each monitoring point is:

[0062] P1=|C0-C i | / C0

[0063] Wherein, P1 is the TDS value change ratio of a monitoring point; C0 is the TDS value reference value collected by the TDS sensor 221 at the monitoring point within a preset period of time after the isolation wall 3 is completed; C i It is the real-time TDS value collected by the TDS sensor 221 at the monitoring point.

[0064] It should be noted that the backfill material of the isolation wall 3 is designed to ensure its fluidity when its moisture content is designed. The long-term change in the water level of the groundwater 8 causes the isolation wall 3 to undergo a dry-wet cycle and there may be dry areas, but heavy metal corrosion itself is a convection diffusion process rather than under dry conditions. At this time, there is no need to consider the possibility of breakdown of the isolation wall, and there is no need to consider monitoring and early warning of changes in pollutant concentrations. When the water level increases significantly over time, turn on the TDS sensor to start monitoring the TDS value of the point. If the TDS value changes in multiples (the multiple size can be customized), it can be determined that the isolation wall is broken down.

[0065] The above operations a to e of the data processing module can be performed regularly, for example, once every hour, and the operation interval can be reasonably set according to the timeliness of the warning. The data processing module generates one or more of the above first warning signal, the second warning signal, the third warning signal, and the fourth warning signal, and sends the warning signal to the interactive terminal to remind the operation and maintenance personnel of the isolation wall 3, so as to judge whether the isolation wall 3 is at risk of being broken down as an auxiliary means, and take repair measures in time.

[0066] Example 2

[0067] See also Figure 6 This embodiment provides a monitoring and early warning system for a soil-bentonite isolation wall. The difference from the monitoring and early warning system in Embodiment 1 is that the construction direction of the isolation wall 3 is non-linear, that is, a right-angle turn composed of two straight lines. Of course, in other embodiments, other turning angles can also be set, and the number of turns can also be increased. In this embodiment, a support frame 1 is set at the turning point, and the support frames 1 and vertical points at other straight lines still refer to the setting principle of the straight line construction direction.

[0068] Specifically, the construction thickness of the isolation wall 3 of this embodiment is 0.6m, the total length is 50m, and it is divided into a 25m horizontal straight line construction part and a 25m longitudinal straight line construction part, with a turn in the middle. The design of monitoring points still follows the principle of close spacing of shallow points and loose spacing of deep points, and ensures that there must be points at the depth of the interface between the permeable layer 5 and the waterproof layer 6. The horizontal spacing of adjacent support frames 1 does not need to be exactly the same, but the spacing size should be close to ensure the accuracy of point data measurement.

[0069] Example 3

[0070] This embodiment provides a construction and monitoring method for the soil-bentonite isolation wall in Embodiment 1 or Embodiment 2, comprising the following steps:

[0071] S1. Construction of guide wall 4: Mark the construction position of isolation wall 3 according to the construction design drawing, determine the excavation area of ​​guide wall 4 on both sides, pour concrete after excavation to form guide wall 4, and set the curing time. The design thickness of guide wall 4 is 0.3m, the excavation depth is 0.5m, and the top of guide wall 4 is 0.2m above the ground; the curing time is 7 to 14 days; in step S2, the specified depth of water-proof layer 6 is 2m.

[0072] S2. Digging trenches: Dig downwards at the location where the isolation wall 3 is to be built, first penetrate the permeable layer 5 of the soil, then dig to the specified depth of the impermeable layer 6 at the bottom of the permeable layer 5 to form a trench, and remove the soil debris at the bottom of the trench.

[0073] S3. Build a monitoring and early warning system; wherein, the monitoring device 2 is pre-installed on the support frame 1 according to the layout design, and the breakdown direction of the pollutants is determined according to the flow direction of the groundwater 8, so that the main monitoring module on the support frame 1 is set inside the proposed isolation wall 3, and the auxiliary monitoring module on the support frame 1 is set on the side of the proposed isolation wall 3 away from the pollution source.

[0074] S4. Backfill wall material: Use the wall material obtained by evenly mixing silty clay and composite modified bentonite mud to protect the trench, and then fill the excavated trench to form the isolation wall 3.

[0075] S5, capping: laying in-situ foundation soil on the top of the isolation wall 3 and the guide wall 4 to form a covering soil layer 7 and compacting it.

[0076] S6. Utilize the data processing module to receive the monitoring data collected by the monitoring device 2 and regularly perform early warning analysis on the isolation wall 3.

[0077] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A monitoring and early warning system for a soil-bentonite isolation wall, characterized in that: include: A support frame (1) comprises a first vertical pipe (11) and a second vertical pipe (12); the first vertical pipe (11) is arranged at a central axis position inside a separation wall (3), and the second vertical pipe (12) is arranged on a side of the separation wall (3) that is away from a pollution source, i.e., an outflow side; the first vertical pipe (11) and the second vertical pipe (12) are both provided with a plurality of monitoring points along a depth direction, and the monitoring points on the two vertical pipes correspond to each other one by one and have the same depth; A monitoring device (2) comprises a main monitoring module arranged on a first vertical pipe (11) and an auxiliary monitoring module arranged on a second vertical pipe (12); the main monitoring module is used to collect the strain and pore pressure of each internal monitoring point in real time during the construction of the isolation wall (3), and is also used to collect the resistivity and water content of each internal monitoring point in real time after the construction of the isolation wall (3) is completed; the auxiliary monitoring module is used to collect the water level on the outflow side of the isolation wall (3) and the TDS value of each monitoring point in real time after the construction of the isolation wall (3) is completed; A data processing module is used to: a. send the strain and pore pressure of each monitoring point inside the isolation wall (3) during the construction period to an interactive terminal for feedback to adjust the on-site environmental conditions during the construction period; b. calculating the resistivity change ratio according to the real-time resistivity of each monitoring point, and generating a first warning signal when the resistivity change ratio of any monitoring point exceeds a preset first change ratio threshold; c. Correcting the wall permeability coefficient according to the real-time moisture content of each monitoring point, and calculating the permeability coefficient change ratio. When the permeability coefficient change ratio of any monitoring point exceeds a preset second change ratio threshold, a second warning signal is generated; d. determining whether the water level on the outflow side of the isolation wall (3) exceeds a preset water level threshold, and if so, generating a third warning signal; e. When the change in water level per unit time exceeds the fluctuation range of the background value of the groundwater level at the site, the TDS value change ratio is calculated based on the real-time TDS value of each monitoring point. When the TDS value change ratio of any monitoring point exceeds the preset third change ratio threshold, a fourth warning signal is generated.

2. A soil-bentonite isolation wall monitoring and early warning system according to claim 1, characterized in that: The main monitoring module comprises a plurality of groups of first data acquisition components (21) distributed along the depth direction, and the auxiliary monitoring module comprises a plurality of groups of second data acquisition components (22) distributed along the depth direction; the first data acquisition components (21) and the second data acquisition components (22) are in one-to-one correspondence and are respectively arranged at corresponding monitoring points; each group of first data acquisition components (21) comprises a strain sensor (211), a pore pressure sensor (212), a resistivity probe (213) and a TDR sensor (214), which are respectively used to collect strain, pore pressure, resistivity and water content at the corresponding monitoring point; each group of second data acquisition components (22) comprises a TDS sensor (221) for collecting the TDS value of the corresponding monitoring point; the auxiliary monitoring module also comprises a water level monitoring float (23) for collecting the water level at the outflow side of the isolation wall (3).

3. A soil-bentonite isolation wall monitoring and early warning system according to claim 2, characterized in that: The calculation formula for the resistivity change ratio based on the real-time resistivity of each monitoring point is: N1=|ρ0-ρ i | / p0 Wherein, N1 is the resistivity change ratio of a monitoring point; ρ0 is the resistivity reference value collected by the resistivity probe (213) at the monitoring point within a preset period of time after the isolation wall (3) is completed; ρ i It is the real-time resistivity collected by the resistivity probe (213) at the monitoring point.

4. A soil-bentonite isolation wall monitoring and early warning system according to claim 2, characterized in that: The calculation formula for correcting the wall permeability coefficient according to the real-time moisture content of each monitoring point is: Where, k is the permeability coefficient; FSI is the free expansion coefficient; e is the porosity; ω is the real-time water content of a monitoring point; A and B are constants fitted according to the bentonite material; The calculation formula of permeability coefficient change ratio is: M1=|k0-k i | / k0 Wherein, M1 is the permeability coefficient change ratio of a monitoring point; within a preset period of time after the isolation wall (3) is completed, the moisture content reference value collected by the TDR sensor (214) at the monitoring point is ω0; k0 is the wall permeability coefficient corrected by ω0; k i It is the wall permeability coefficient corrected by the real-time moisture content of the monitoring point.

5. The monitoring and early warning system for a soil-bentonite isolation wall according to claim 2 is characterized in that: The calculation formula for calculating the TDS value change ratio based on the real-time TDS value of each monitoring point is: P1=|C0-C i | / C0 In the formula, P1 is the TDS value change ratio of a monitoring point; C0 is the TDS value reference value collected by the TDS sensor (221) at the monitoring point within a preset period of time after the isolation wall (3) is completed; C i It is the real-time TDS value collected by the TDS sensor (221) at the monitoring point.

6. A soil-bentonite isolation wall monitoring and early warning system according to claim 2, characterized in that: At each monitoring point of the first vertical pipe (11), a strain sensor (211), a pore pressure sensor (212), a resistivity probe (213) and a TDR sensor (214) are distributed in a circumference in the same horizontal plane and are fixedly connected to the outer circumference of the first vertical pipe (11); the second vertical pipe (12) comprises an outer pipe and an inner pipe which are coaxially arranged to form a sandwich, a water level monitoring float (23) is arranged in the sandwich, a plurality of through holes which are evenly opened on the pipe wall of the outer pipe and are connected to the sandwich, and a geotextile is wrapped on the outer side of the outer pipe, and at each monitoring point of the second vertical pipe (12), a TDS sensor (221) is fixedly connected to the geotextile on the outer side of the second vertical pipe (12).

7. A soil-bentonite isolation wall monitoring and early warning system according to any one of claims 2 to 6, characterized in that: The support frame (1) also includes a transverse tube (13); the transverse tube (13) is horizontally arranged on the top of the guide walls (4) on both sides of the isolation wall (3); the tops of the first vertical tube (11) and the second vertical tube (12) are fixedly connected to the transverse tube (13), and form a "T"-shaped structure whose plane is perpendicular to the construction direction of the isolation wall (3).

8. A soil-bentonite isolation wall monitoring and early warning system according to claim 7, characterized in that: The bottoms of the first vertical tube (11) and the second vertical tube (12) are both anchor ends, and the depth of the anchor ends is greater than the bottom depth of the isolation wall (3).

9. A soil-bentonite isolation wall monitoring and early warning system according to claim 8, characterized in that: A plurality of groups of support frames (1) are provided, and the plurality of groups of support frames (1) are sequentially distributed along the construction direction of the isolation wall (3); the number of the monitoring devices (2) is the same as that of the support frames (1) and corresponds one to one.

10. A soil-bentonite isolation wall monitoring and early warning system according to claim 9, characterized in that: The number of monitoring points in each group of monitoring devices (2) is not less than five, the spacing between adjacent monitoring points increases with the depth, and monitoring points are provided at the interface between the permeable layer (5) and the waterproof layer (6) in the soil; when the construction direction of the isolation wall (3) is straight, the number of support frames (1) is not less than three groups, and the horizontal spacing between adjacent support frames (1) is not greater than 15m; when the construction direction of the isolation wall (3) is non-straight, support frames (1) are provided at the turning points, and the support frames (1) at other straight lines are still set according to the setting principle of the straight construction direction.

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