A waterproofing construction pretreatment method for a high-water-content mucky clay base surface

Abstract

The application discloses a kind of high water content silt clay surface waterproof construction pretreatment methods, belong to civil engineering waterproof construction technical field.The method includes: S1, electrolytic catalytic dehydration, electrode array is laid on the base surface and is injected into catalytic electrolyte, and step voltage is applied to carry out electroosmotic dehydration;S2, spray strengthening, first non-continuous strip spraying and second continuous full coverage spraying are used to form waterproof film;S3, monitoring system integration, when coating surface dries, strain sensing node hydraulic implantation is implanted below the base surface and initial reference value is recorded;S4, feedback repair early warning, when strain change rate exceeds threshold value, alarm and record abnormal coordinates to guide repair.The application realizes the integration of efficient controllable dehydration of high water content silt clay surface, high-strength spraying of wet base surface, non-destructive intelligent monitoring and early warning feedback repair, and is suitable for waterproof engineering construction in coastal beach, reclamation area and soft soil area.

Description

Technical Field

[0001] This invention belongs to the field of waterproofing construction technology in civil engineering, specifically, it relates to a pretreatment method for waterproofing construction of silty clay base with high water content. Background Technology

[0002] In the field of waterproofing construction in civil engineering, waterproofing treatment of silty clay foundations with high water content has been a long-standing technical challenge. With the rapid development of infrastructure construction in coastal mudflats, reclamation areas, and soft soil areas, how to achieve a reliable and durable waterproof layer on silty clay foundations with a natural water content close to or exceeding the liquid limit (usually ≥50%) has become a key bottleneck restricting project quality and progress.

[0003] In existing technologies, the pretreatment of waterproofing for soft soil surfaces with high moisture content mainly faces the following technical problems: 1. Energy consumption and controllability issues of electroosmotic dehydration process Electroosmosis is a common method for reducing the moisture content of soft soil, but traditional electroosmosis processes suffer from drawbacks such as severe electrode polarization, high energy consumption, and a significant decrease in dehydration efficiency over time. Some improved solutions employ intermittent energization or reverse electric field techniques, but these often require complex control strategies and lack clear criteria for terminating dehydration. More importantly, the determination of the electroosmosis endpoint in existing technologies largely relies on subjective experience (such as visually inspecting surface cracks or listening to sounds upon tapping), making it difficult to achieve standardized and repeatable operations on-site. This leads to unstable dehydration quality, which in turn affects the bonding reliability of subsequent waterproofing layers.

[0004] 2. Application compatibility issues of waterproof coatings on damp substrates On silty clay substrates that have undergone dehydration but still retain a relatively high moisture content (approximately 20%), conventional waterproofing coatings face problems such as poor wetting properties, low adhesion strength, and susceptibility to blistering and peeling. Especially in low-temperature environments, the curing speed of most waterproofing materials decreases significantly, and the adhesion strength deteriorates severely. Although some studies have attempted to improve interfacial adhesion through nano-modification or plasma treatment, these methods often require specialized equipment or complex on-site processes, and the problem of uneven dispersion of nanomaterials has not been fundamentally solved. Furthermore, waterproofing construction is inevitably interrupted due to weather, equipment failure, or other reasons. After interruption, the activity of the coating surface is rapidly lost. Current technologies lack feasible solutions for effectively resuming work without removing the entire coating.

[0005] 3. The integration challenge of structural health monitoring and waterproofing layer To assess the long-term stability of soft soil foundations, strain and settlement sensors are often installed during construction. Traditionally, these sensors are drilled and installed separately before or after the waterproofing layer is applied. This not only damages the existing waterproofing layer but also results in low sensor positioning accuracy and susceptibility to signal interference. Some technologies attempt to integrate sensors with waterproofing membranes, but these are difficult to apply to on-site spray-applied waterproofing systems. More importantly, existing monitoring systems are mostly open-loop designs, meaning they only collect data without linking it to construction and maintenance decisions, failing to provide timely warnings and repair guidance for abnormal deformation.

[0006] In summary, there is an urgent need for a pretreatment method that can systematically solve the entire chain of problems, including "efficient and controllable dehydration, high-strength spraying on damp substrates, non-destructive intelligent monitoring, and early warning feedback repair," in order to truly meet the engineering requirements for waterproofing construction on silty clay substrates with high moisture content. Summary of the Invention

[0007] The purpose of this invention is to provide a pretreatment method for waterproofing construction on a silty clay substrate with high water content, aiming to solve the problems mentioned in the background art.

[0008] The objective of this invention can be achieved through the following technical solutions: A pretreatment method for waterproofing a silty clay substrate with high moisture content includes the following steps: S1. Electrolytic catalytic dehydration: An electrode array is deployed on the silty clay substrate, a catalytic electrolyte is injected, and a stepped voltage is applied for electroosmotic dehydration until the average moisture content of the surface soil drops to ≤20%, and the energy consumption increment for dehydration within 30 minutes is ≤10 W·h / m². 2 ; S2. Spraying reinforcement: On the base surface after dehydration meets the standards, a layered spraying process is used to apply a waterproof adhesive to form a continuous waterproof membrane. The first spraying is a non-continuous strip spraying, and the second spraying is a continuous full-coverage spraying. If the spraying interruption time exceeds the threshold, the surface film is removed mechanically first, and then an interface revitalizer is applied to restore the coating activity before continuing the construction. S3. Monitoring system integration: After spraying is completed and the coating is in a surface-dry state, the strain sensor node is implanted into the stable soil layer below the base surface through guide holes and hydraulic pressing, and the initial strain reference value is recorded. S4. Feedback Repair Early Warning: Based on the real-time strain data obtained by the monitoring system, when the strain change rate of adjacent monitoring cycles exceeds the set threshold, an alarm signal is triggered, and the coordinates of abnormal points are automatically recorded to guide local grouting or secondary spraying repair.

[0009] In step S1, the electrode array is arranged in an equilateral triangular grid, and the electrode spacing is based on the soil plasticity index. Calculate using the following empirical formula:

[0010] Where D is the spacing in meters, and k is a coefficient ranging from 0.5 to 1.2; the specific value is determined by a small-scale electroosmosis test on site.

[0011] The catalytic electrolyte comprises: 5-8 wt% chitosan hydrochloride, 0.8-1.2 wt% sodium chloride, and the balance being water; the injection process employs three-stage pressure control. Initial penetration phase: pressure 0.15±0.02 MPa, ends when the injection pressure shows no decreasing trend for 5 minutes; Accelerated migration phase: pressure 0.22±0.03 MPa, ends when the soil resistivity between electrodes drops below 60% of the initial value; Steady-state dehydration stage: pressure 0.25±0.03 MPa, continuing until overflow from the orifice.

[0012] The stepped voltage control method is as follows: The initial voltage should be ≤3V; if the real-time calculated dehydration rate (average moisture content decrease per 30 minutes) is less than 0.8% / h for two consecutive cycles, increase the voltage by 0.5V; after each voltage increase, maintain the voltage for at least 30 minutes before proceeding to the next round of judgment; the maximum voltage should not exceed 6V. When the detected current density is >0.5 A / m 2 When this occurs, the voltage is automatically reduced by 10% and electrode cooling is activated.

[0013] In step S2: First coat: 0.3–0.5 kg / m² 2 The coating is applied in strip spraying, with the spray gun applied along a main direction at intervals of 40-50 cm, forming a grid-like coating that is not completely covered. First coat: 0.5–0.7 kg / m² 2 Use spiral spray guns or cross-spraying to ensure that the overlap rate of the spray trajectory is ≥1 / 3 of the gun width, forming a continuous and dense waterproof membrane; The interval between two sprayings should be 3 to 10 minutes, and the first coat should be applied until the surface is matte and free of flow.

[0014] The waterproof adhesive is a polyurethane-modified epoxy resin-based material.

[0015] The interruption timeout threshold is 2 hours; the post-interruption and pre-resumption procedures include: Scraping procedure: Use a wire brush to scrape off the formed conjunctiva in a crisscross pattern, with a scraping depth of ≤1 mm; Revitalizing agent application: Apply an 8% (w / w) polyetheramine aqueous solution at a dosage of 0.15–0.20 kg / m². 2Apply the coating until the substrate has a uniform reflective finish; before resuming work, the moisture content of the substrate must be retested to ensure it is still ≤20%.

[0016] In step S3, the surface dry state is defined as follows: when you lightly press the coating surface with your finger, there is no paint transfer, the touch is rough, and it is not sticky; this state is reached 15 to 20 minutes after the second coat of spraying under standard environmental conditions of 25°C and RH 60%; the waiting time should be adjusted according to the temperature and humidity of the site during construction.

[0017] In step S3, the method for implanting the sensor node includes: Pre-drilling of guide holes: Drill holes at preset coordinate points using a tool with a drill bit diameter of 8 mm and a rotation speed of ≤300 rpm. The hole depth is 2 / 3 of the base thickness or a fixed value of 80 mm. Hydraulic implantation: Place the sensor at the orifice and press it in with a pressure of 0.5 to 0.8 MPa until the top of the sensor is flush with the base surface or reaches the preset depth mark; Sealing treatment: Immediately after implantation, apply a sealant compatible with the original waterproof layer around the sensor to prevent moisture from seeping in along the interface.

[0018] In step S4, the strain change rate threshold is set to 10% to 20%, and the specific value is determined by field tests based on the engineering safety level and soil creep characteristics. After the alarm is triggered, the system automatically prints or stores the GIS coordinates of the abnormal point and issues an audible and visual alarm. At the same time, triple redundancy backup of data is initiated.

[0019] The anode used in step S1 is a soluble sacrificial anode made of Mg-Al-Zn-Mn alloy with an aluminum content of 6.0±0.2 wt%; the cathode is a titanium alloy plate with a surface area not less than 1.5 times the total surface area of ​​the anode; after the dehydration operation is completed, the anode needs to be immersed in a regeneration solution containing 2.5 wt% sodium citrate and 1 wt% sodium molybdate for electrochemical regeneration treatment at pH 8.5 to 9.0.

[0020] The beneficial effects of this invention are: I. This invention employs a bio-based catalytic electrolyte containing chitosan hydrochloride and sodium chloride. By optimizing the double-layer structure of clay particles, it significantly reduces the interfacial resistance during electroosmosis, thereby suppressing electrode polarization and improving current efficiency. Combined with a step-by-step dynamic voltage regulation strategy (automatically increasing voltage based on the real-time dehydration rate and automatically decreasing voltage during current overload), closed-loop control of the dehydration process is achieved. More importantly, this invention proposes a dual-condition dehydration termination criterion: the average moisture content of the surface soil ≤20% and the increase in dehydration energy consumption ≤10 W·h / m³ within 30 consecutive minutes. 2This criterion is quantifiable and reproducible, completely eliminating the subjective experience-based judgments such as "listening to the sound and looking at the water spots" in traditional methods, and ensuring the consistency of dehydration effects under different construction teams and environmental conditions.

[0021] II. This invention employs a layered spraying strategy of "discontinuous strip spraying + continuous full spraying": the first strip spray forms a grid-like "keel," controlling the amount used per coat and providing physical anchoring points for the second coat, significantly reducing the risk of paint running on damp substrates. More importantly, this invention is the first to propose a solution for resuming work after spraying interruptions. When work stoppage exceeds 2 hours, a combination of mechanical scraping to remove the film and application of a polyetheramine interface reactivator allows the cured coating surface to regain chemical reactivity, thus ensuring the interlayer adhesion strength between the old and new coatings. Tests show that after treatment with the reactivator of this invention, the interlayer pull-out strength can be restored to over 85% of the original continuous spraying state, while conventional sanding only restores about 50%. This technology solves the problem of large-scale rework caused by uncontrollable factors such as weather and equipment failure during on-site construction, significantly improving construction efficiency and economy.

[0022] Third, this invention precisely controls the timing of sensor implantation when the waterproof coating is surface dry (feeling slightly rough but not sticky, with no coating transfer). At this point, the coating has sufficient mechanical strength to resist the risk of tearing during drilling; simultaneously, the coating is not yet fully cured, allowing the sealant to form a chemical bond with the coating after implantation, effectively sealing seepage channels. The implantation method employs a "guide hole + hydraulic pressing" approach, avoiding disturbance to the coating and soil caused by hammer vibration. Immediate sealing is performed after implantation, truly achieving integrated non-destructive monitoring. Furthermore, this invention specifies a quantitative standard for sensor implantation depth (2 / 3 of the base layer thickness or a fixed 80mm) and ensures a positioning error ≤0.5m through GPS coordinate verification, providing a reliable benchmark for spatial analysis of subsequent long-term monitoring data.

[0023] Fourth, when the strain change rate of adjacent monitoring cycles exceeds the preset threshold (10%~20%), the system automatically triggers an audible and visual alarm and records the GIS coordinates of the abnormal points, guiding engineers to carry out targeted local grouting or secondary spraying repairs. This closed-loop design extends the invention beyond pre-treatment during the construction phase to structural health management during the operational phase, significantly improving the reliability of waterproofing projects throughout their entire lifecycle. Data fault tolerance mechanisms (heartbeat packets sent by sub-nodes every 6 hours, triple backup by the master node) and electrical protection measures (fuse ejection for 5 seconds during 120% overcurrent) further ensure the stable operation of the monitoring system in harsh environments. Attached Figure Description

[0024] The present invention will now be further described with reference to the accompanying drawings.

[0025] Figure 1 This is a schematic diagram of the process of the present invention. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1

[0028] Project Background: A road construction project in a coastal reclamation area requires the application of a waterproof layer on a silty clay substrate with a natural moisture content of 68%, a liquid limit moisture content of 52%, and a plasticity index (Ip) of 24. The substrate treatment area is approximately 200 m². 2 The treatment requires that the surface soil moisture content be ≤20%, and long-term strain monitoring nodes be installed.

[0029] Construction process (see) Figure 1 ): S1, Electrolytic catalytic dehydration S101, Electrode Layout Based on the plasticity index Ip=24, and taking the coefficient k=0.8, the electrode spacing is determined to be 0.19 m according to the formula (rounded down for ease of construction).

[0030] An equilateral triangular array was used to arrange the anode (Mg-Al-Zn-Mn soluble anode, with a measured Al content of 6.05 wt%) and titanium alloy cathode plate (the total area of ​​the cathode plate is approximately 1.6 times the total surface area of ​​the anode).

[0031] The construction team used a torque wrench to tighten the electrode connector to the set torque (hearing two "clicks" to confirm tightening), and sprayed red marker paint on the positioning point.

[0032] S102, Catalyst injection Catalytic solution preparation: Add chitosan hydrochloride (6.2 wt%) and sodium chloride (1.0 wt%) to the mixing tank, with the remainder being tap water. After stirring evenly, use a Baumé meter to check the concentration to confirm that it meets the requirements.

[0033] Three-stage pressurized injection: Initial infiltration stage: Start the pump and maintain a pressure of 0.15 MPa. After 8 minutes of injection, the injection pressure stabilized and stopped decreasing (indicating that the surface soil was saturated with the catalyst), thus ending this stage.

[0034] Accelerated migration phase: The pressure is increased to 0.22 MPa and injection continues for 35 minutes. During this period, the soil resistivity between the electrodes is measured using a resistivity monitor. The initial value is 120 Ω·m, which decreases to 68 Ω·m (approximately 57% of the initial value). This phase ends when the ≤60% condition is met.

[0035] Steady-state dehydration stage: Pressurize to 0.25 MPa and continue injection until clear liquid overflows from each injection port, then stop injection. A total of 480 L of catalyst solution has been injected.

[0036] S103, Power-on control and dynamic voltage regulation Connect the electrode cables in the order of red, blue, and yellow, and set the initial voltage to 2.5 V.

[0037] The dehydration rate is automatically calculated every 30 minutes (based on the average value of the buried moisture content sensors).

[0038] In the first 30 minutes: the moisture content dropped from 68% to 62%, and the dehydration rate was 12% / h (far above the threshold). Second 30 minutes: Reduced to 57%, rate 10% / h; The third 30-minute period: decreased to 53%, rate 8% / h; Fourth 30-minute period: dropped to 49%, rate 8% / h (still higher than 0.8% / h); The fifth 30-minute period: decreased to 47%, rate 4% / h; The sixth 30-minute period: decreased to 44.5%, rate 2.5% / h; The seventh 30-minute period: decreased to 43%, rate 1.5% / h; Eighth 30-minute mark: Reduced to 42%, rate 1.0% / h; Ninth 30-minute interval: dropped to 41.2%, rate 0.8% / h (first time below the threshold).

[0039] Triggering voltage boost: When the dehydration rates are 0.8% / h and 0.7% / h for two consecutive cycles (i.e., the 9th and 10th 30-minute cycles, respectively) (both <0.8% / h), the control system automatically increases the voltage by 0.5 V to 3.0 V.

[0040] Overcurrent protection: 15 minutes after voltage boost, a local current density increase to 0.52 A / m was detected. 2 (Threshold 0.5 A / m) 2 The system automatically reduced the voltage by 10% (to 2.7 V) and activated the cooling fan to cool the electrodes. After 5 minutes, the current density recovered to 0.46 A / m. 2 .

[0041] The pressure is then increased again based on the dehydration rate, with the highest voltage reaching 4.5 V.

[0042] S104, Termination Decision (Dual Conditions) Condition 1: After 22 hours of operation, the average moisture content measured by the multi-point needle moisture meter (insertion depth 5 cm) is 19.3% ≤ 20%.

[0043] Condition 2: From hour 21.5 to hour 22, the energy consumption increment is 7.6 W·h / m 2 ≤10 W·h / m 2 Furthermore, the energy consumption increment over the following 30 minutes is 5.2 W·h / m³. 2 All of them meet the requirements.

[0044] Termination of operation: The control system automatically cuts off the power and issues an audible and visual prompt, "Dehydration complete." The construction personnel recorded the total energy consumption as 478 W·h / m³. 2 This is in line with expectations.

[0045] Electrode regeneration (as a equipment maintenance step, performed after S1 and before moving to the next construction section): Immerse the pulled-out anode in a regeneration solution tank (2.5 wt% sodium citrate + 1 wt% sodium molybdate, pH=8.7).

[0046] The titanium alloy cathode plate is 8 cm away from the anode. After 15 minutes of regeneration, the anode is removed and dripped with water for 10 seconds before being put into use. When the pH of the regeneration solution rises to 9.1, the solution is automatically drained and replenished with fresh solution.

[0047] S2, Spray coating reinforcement S201, Construction Preparation After confirming that the S1 dehydration standard was met, the area was cleared and a warning tape was set up at the boundary. The moisture content of the base surface was retested and found to be 19.0%, which meets the requirements.

[0048] S202, Layered spraying (The waterproof adhesive used in this embodiment is the epoxy resin waterproof coating of Shandong Lanmeng Anticorrosion Technology Co., Ltd., model DH1900) First coat: 0.42 kg / m² 2 The spray gun operator applies the coating in strips spaced 45 cm apart (each strip approximately 15-18 cm wide) along an east-west direction, creating a partially covered grid-like coating. After spraying, allow the coating to stand for 4 minutes to observe a matte finish and no flow.

[0049] Second coat: 0.63 kg / m² 2 Starting from the center point, use a spiral gun to check the overlap rate of the trajectory, which should be approximately 35% (≥1 / 3 of the gun width), to ensure the formation of a continuous and dense waterproof membrane.

[0050] S203, Emergency Interruption Handling (Simulating Work Stoppage Due to Strong Winds) When the second coat of paint was about 60% complete, a level 7 gust of wind forced a work stoppage of 2 hours and 30 minutes (exceeding the 2-hour threshold).

[0051] Pre-resumption procedures: Scraping operation: Use a hard steel wire brush to scrape off the cured surface film in a cross shape, with a scratch depth of about 0.7 mm (≤1 mm).

[0052] Revitalizing agent application: Dip a brush in an 8 wt% polyetheramine aqueous solution and apply it evenly to the area to be treated using a longitudinal-then-transverse pattern. The application rate is 0.18 kg / m². 2 After application, the substrate exhibits a uniform reflective sheen.

[0053] Retested moisture content: The moisture content of the base surface measured by a needle moisture meter is still 18.5% (≤20%), which meets the conditions for resuming work.

[0054] Continue with the remaining coats to complete the final waterproof membrane, ensuring a continuous appearance without any delamination.

[0055] S3, Monitoring System Integration S301, Window Control (Table Status Determination) After all coats of paint have been applied, wait 18 minutes in a standard environment (22°C, RH 65%). Gently press the coating surface with your finger: if there is no paint transfer and the surface feels slightly rough and not sticky, it is considered to be surface dry, and sensor implantation can begin immediately.

[0056] S302, Sensor Implantation Operation Pre-fabrication of guide holes: According to the design coordinates (one node per 10 m × 10 m grid), use an 8 mm drill bit and control the rotation speed at 280 rpm to drill holes. The hole depth is 2 / 3 of the base thickness (base thickness 150 mm, hole depth 100 mm).

[0057] Hydraulic implantation: Place the strain sensor node at the orifice and slowly press it in using a hydraulic indenter at a pressure of 0.65 MPa until the top of the sensor is flush with the base surface. Confirm that the depth mark is in place.

[0058] Sealing treatment: Immediately after implantation, apply a two-component polysulfide sealant compatible with the original waterproof layer around the sensor, with an edge width of about 20 mm, to ensure no water seepage channels.

[0059] S303, Function Activation and Baseline Calibration Positioning verification: Using a GPS surveying instrument to navigate around each node, the maximum planar error is 0.3 m (<0.5 m), which meets the requirements.

[0060] Strain reference calibration: After standing for 1 hour, read the initial strain value of each sensor and record it as the reference (the initial strain value of node #03 is 0.15%).

[0061] S4. Feedback and Repair Warning (System Configuration and Simulation) S401, Threshold Setting Based on the safety level (Level II) of the project, the strain change rate threshold is set at 15%. That is, if the strain change rate exceeds 15% over an adjacent 7-day period, the system will trigger an alarm.

[0062] S402, Data Fault Tolerance and Electrical Protection Monitoring system settings: Child nodes actively send heartbeat data packets to the master node every 6 hours. If the master node fails to receive a heartbeat from a child node twice consecutively, it will trigger a local indicator light flashing alarm and initiate data retransmission.

[0063] Electrical protection: Each sensor node circuit has a built-in fuse with a rated current of 0.5 A. In actual testing, when a node experiences a short circuit current of 0.62 A (124% of the rated value) due to moisture and this current remains for 5 seconds, the fuse ejects a red indicator rod, prompting maintenance personnel to replace it.

[0064] S403, Early Warning Simulation (Feedback Repair) During the routine system analysis on the 45th day after construction, it was found that the strain change rate of node #03 was +17.2% (from 0.15% to 0.176%) in the two weeks following construction, exceeding the 15% threshold.

[0065] The system automatically triggered an audible and visual alarm and printed a GIS location bar for the abnormal point: "Node #03, coordinates (X:32566.2, Y: 89733.5), change rate 17.2%, verification recommended." Based on the location, on-site engineers performed grouting reinforcement around the node and locally recoated the waterproof layer. Subsequent monitoring after treatment showed that the strain tended to stabilize, indicating a successful repair.

[0066] Those skilled in the art will understand that the above embodiments are merely exemplary descriptions and are not intended to limit the scope of protection of the present invention. The following situations all constitute equivalent substitutions or obvious modifications of the present invention: The concentrations of chitosan hydrochloride and sodium chloride in the catalyst solution can be adjusted within the ranges of 5~8 wt% and 0.8~1.2 wt%, respectively, as long as the effect of promoting double-layer compression and reducing electroosmotic energy consumption is achieved.

[0067] The electrode spacing coefficient k can be selected between 0.5 and 1.2 based on the results of small-scale electroosmosis tests in the field. The higher the plasticity index of the soil, the smaller the spacing should be.

[0068] The maximum value of the stepped voltage can be set according to the project scale and power supply capacity, but it should not exceed 6V to avoid excessive electrolysis and heat generation.

[0069] The interruption timeout threshold can be adjusted appropriately according to the ambient temperature and coating formulation. For example, it can be extended to 3 hours in low-temperature environments, but the effect of the reviving agent needs to be re-verified.

[0070] The strain rate threshold can be selected within the range of 10% to 20% depending on the importance of the project; a lower value is recommended for important bridges or sensitive buildings.

[0071] The above detailed embodiments provide a specific description of the analytical methods involved in this invention. It should be noted that the above description is only intended to help those skilled in the art better understand the methods and ideas of this invention, and is not intended to limit the scope of the invention. Without departing from the principles of this invention, those skilled in the art can make appropriate adjustments or modifications to this invention, and such adjustments and modifications should also fall within the protection scope of this invention.

Claims

1. A pretreatment method for waterproofing a silty clay substrate with high moisture content, characterized in that, Includes the following steps: S1. Electrolytic catalytic dehydration: An electrode array is deployed on the silty clay substrate, a catalytic electrolyte is injected, and a stepped voltage is applied for electroosmotic dehydration until the average moisture content of the surface soil is reduced to ≤20%, and the energy consumption increment for dehydration within 30 minutes is ≤10 W·h / m 2 ; S2. Spraying reinforcement: On the substrate after dehydration, a layered spraying process is used to apply a waterproof adhesive to form a continuous waterproof membrane; S3. Monitoring system integration: When the spraying is completed and the coating is in a surface-dry state, the strain sensor node is implanted into the stable soil layer below the base surface through guide holes and hydraulic pressing, and the initial strain reference value is recorded. S4. Feedback Repair Early Warning: Based on the real-time strain data obtained by the monitoring system, when the strain change rate of adjacent monitoring cycles exceeds the set threshold, an alarm signal is triggered, and the coordinates of abnormal points are automatically recorded to guide local grouting or secondary spraying repair.

2. The pretreatment method for waterproofing a high-moisture-content silty clay substrate according to claim 1, characterized in that, In step S1, the electrode array is arranged in an equilateral triangular grid, and the electrode spacing is based on the soil plasticity index. Calculate using the following empirical formula: Where D is the spacing in meters, and k is a coefficient ranging from 0.5 to 1.2; the specific value is determined by a small-scale electroosmosis test on site.

3. The pretreatment method for waterproofing a high-moisture-content silty clay substrate according to claim 1, characterized in that, The catalytic electrolyte comprises: 5-8 wt% chitosan hydrochloride, 0.8-1.2 wt% sodium chloride, and the balance being water; The injection process employs a three-stage pressure control: Initial penetration phase: pressure 0.15±0.02 MPa, ends when the injection pressure shows no decreasing trend for 5 minutes; Accelerated migration phase: pressure 0.22±0.03 MPa, ends when the soil resistivity between electrodes drops below 60% of the initial value; Steady-state dehydration stage: pressure 0.25±0.03 MPa, continuing until overflow from the orifice.

4. The pretreatment method for waterproofing a high-moisture-content silty clay substrate according to claim 1, characterized in that, The stepped voltage control method is as follows: Power is applied using a voltage of ≤3V as the starting voltage. The dehydration rate of the current cycle is calculated in real time, which is the average moisture content decrease every 30 minutes, with each monitoring cycle lasting 30 minutes. When the dehydration rate of two consecutive monitoring cycles is lower than 0.8% / h, the current voltage is increased by 0.5V. After each voltage increase, the voltage is maintained for at least 30 minutes before the next voltage increase is performed. The maximum voltage applied does not exceed 6V. During the energizing process, when a current density > 0.5 A / m is detected... 2 When this happens, the current voltage will be automatically reduced by 10%, and the electrode cooling device will be activated.

5. The pretreatment method for waterproofing a high-moisture-content silty clay substrate according to claim 1, characterized in that, The anode used in step S1 is a soluble sacrificial anode made of Mg-Al-Zn-Mn alloy with an aluminum content of 6.0±0.2 wt%; the cathode is a titanium alloy plate with a surface area not less than 1.5 times the total surface area of ​​the anode; after the dehydration operation is completed, the anode is immersed in a regeneration solution containing 2.5 wt% sodium citrate and 1 wt% sodium molybdate, and electrochemical regeneration is carried out under pH 8.5 to 9.0 conditions.

6. The pretreatment method for waterproofing a high-moisture-content silty clay substrate according to claim 1, characterized in that, Step S2, the layered spraying process, includes a first coat and a second coat: First coat: 0.3–0.5 kg / m² 2 The coating is applied in strip spraying, with the spray gun applied along a main direction at intervals of 40-50 cm, forming a grid-like coating that is not completely covered. First coat: 0.5–0.7 kg / m² 2 Use spiral spray guns or cross-spraying to ensure that the overlap rate of the spray trajectory is ≥1 / 3 of the gun width, forming a continuous and dense waterproof membrane; The interval between two coats is 3 to 10 minutes. The second coat should be applied when the surface of the first coat is matte and free of flow.

7. The pretreatment method for waterproofing a high-moisture-content silty clay substrate according to claim 1, characterized in that, If the spraying interruption time in step S2 exceeds the preset 2-hour threshold, the handling before resuming work after the interruption includes: Scraping procedure: Use a wire brush to scrape off the formed conjunctiva in a crisscross pattern, with a scraping depth of ≤1 mm; Interface revitalizer application: Apply an 8% (w / w) polyetheramine aqueous solution at a dosage of 0.15–0.20 kg / m². 2 Apply until the base surface has a uniform reflective finish; Moisture content retest: The moisture content of the base surface is retested before resuming work. Construction can only continue after it is confirmed to be ≤20%.

8. The pretreatment method for waterproofing a high-moisture-content silty clay substrate according to claim 1, characterized in that, In step S3, the surface dry state is defined as: when you lightly press the coating surface with your finger, there is no paint transfer, the touch is slightly rough, and it is not sticky; This state is achieved 15-20 minutes after the second coat of spraying under standard environmental conditions of 25°C and 60% RH. During construction, the waiting time should be adjusted according to the actual temperature and relative humidity on site to achieve the surface-dry state.

9. The pretreatment method for waterproofing a high-moisture-content silty clay substrate according to claim 1, characterized in that, In step S3, the method for implanting the strain sensing node includes: Pre-drilling of guide holes: Drill holes at preset coordinate points using a tool with a drill bit diameter of 8 mm and a rotation speed of ≤300 rpm. The hole depth is 2 / 3 of the base thickness or a fixed value of 80 mm. Hydraulic implantation: Place the sensor at the orifice and press it in with a pressure of 0.5 to 0.8 MPa until the top of the sensor is flush with the base surface or reaches the preset depth mark; Sealing treatment: Immediately after implantation, apply a sealant compatible with the original waterproof layer around the sensor to prevent moisture from seeping in along the interface.

10. The pretreatment method for waterproofing a high-moisture-content silty clay substrate according to claim 1, characterized in that, In step S4, the strain change rate threshold is set to 10% to 20%, and the specific value is determined by field tests based on the engineering safety level and soil creep characteristics. When an alarm signal is triggered, the system automatically prints or stores the GIS coordinates of the abnormal location and issues an audible and visual alarm; at the same time, it initiates triple redundancy data backup.

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