Non-excavation anti-sedimentation well lid height difference regulation method and system

Abstract

The invention relates to a non-excavation anti-sedimentation well lid height difference regulation method and system. Comprising the following steps: performing field investigation and data acquisition, and preparing a corresponding tool according to the acquired data; installing a well mouth gas insulation airbag, monitoring the concentration of combustible materials in the well lid in real time, and predicting the time when the concentration of the combustible materials reaches a safety threshold value; after the concentration of the combustible gas reaches a safety threshold value, a high-frequency coil is installed, and the high-frequency coil is controlled to heat and soften wellhead asphalt through fuzzy PID; physically separating the well lid; heating asphalt around the well lid opening by adopting far infrared heating, and constructing a heat conduction model to predict the temperature condition of the surrounding asphalt until the asphalt is heated to a preset temperature; according to the non-excavation technology provided by the invention, the pavement repairing time can be shortened, the single-point operation time is shortened to be within 3 hours, the influence on traffic is reduced, and compared with a traditional excavation maintenance method, the cost can be saved by 40%, and the carbon emission is reduced by 75%.

Description

Technical Field

[0001] The present invention relates to the field of magnetic gradient measurement technology, and in particular to a method and system for regulating the height difference of a trenchless anti-subsidence manhole cover. Background Art

[0002] Traditional anti-subsidence manhole cover installation techniques (such as loose-lay installation and reverse excavation) suffer from insufficient asphalt compaction around the flange, leading to high manhole cover settlement rates and frequent repairs. Existing technologies rely on cutting and excavation, resulting in long construction cycles, high costs, and significant carbon emissions. A breakthrough in trenchless technology is urgently needed.

[0003] The patent disclosed as: CN200910194107.3 discloses a microwave heating repair method for asphalt mixture pavement around the manhole ring, including the following steps: 1. Transport the microwave heater to the road surface to be repaired, open the manhole cover, and detect the concentration of combustible gas in the well; 2. Place the manhole cover protective cover on the wellhead, place an appropriate amount of new asphalt mixture cold material on the manhole cover protective cover, and place the microwave heater on the wellhead; 3. Start the manhole cover repair mode of the microwave heater, heat the asphalt mixture around the outer edge of the manhole ring for a period of time, and then heat the asphalt mixture cold material in the manhole cover protective cover; 4. Heat the asphalt mixture around the outer edge of the manhole ring and the asphalt mixture cold material in the manhole cover protective cover to the construction temperature; 5. If the asphalt concrete around the outer edge of the original manhole ring is contaminated and cannot be reused, it can be cleaned and the heated asphalt mixture in the manhole cover protective cover can be poured around the manhole ring, and then spread and compacted. There are also the following defects:

[0004] 1. Although the document mentions detecting combustible gas concentrations in the well, it is only a simple detection. It does not mention safety measures such as real-time monitoring of combustible gas concentrations and prediction of when the safety threshold is reached. Heating in the presence of combustible gas in the well poses a safety hazard.

[0005] 2. Using a manhole cover to place cold material before heating requires heating the original pavement and the new cold material twice, resulting in low energy efficiency and long heating times. Furthermore, this method involves pouring the cold material around the manhole for paving and compaction, lacking any regeneration of the original pavement asphalt.

[0006] 3. The proposal only mentions heating the asphalt mixture to the construction temperature, but does not mention the use of precise temperature control methods, which may lead to excessive aging of the asphalt or insufficient heating.

[0007] 4. Cast iron manhole covers will reflect microwaves and cause arc discharge;

[0008] To this end, the present invention proposes a trenchless anti-subsidence manhole cover height difference regulation method and system. Summary of the Invention

[0009] The present invention aims to solve the technical problems existing in the prior art and provides a method and system for regulating the height difference of a trenchless anti-subsidence manhole cover.

[0010] The present invention solves the above-mentioned technical problems with the following technical solutions: a method and system for regulating the height difference of a trenchless anti-settling manhole cover; comprising the following steps:

[0011] S1: Conduct on-site surveys and data collection, and prepare corresponding tools based on the collected data;

[0012] S2: Install a wellhead air barrier to monitor the concentration of combustibles in the manhole cover in real time and predict the time when it reaches the safety threshold;

[0013] S3: After the combustible gas concentration reaches the safety threshold, a high-frequency coil is installed and the fuzzy PID control is used to heat and soften the wellhead asphalt.

[0014] S4: Physical separation of manhole covers;

[0015] S5: Use far-infrared heating to heat the asphalt around the manhole cover, and build a heat conduction model to predict the temperature of the surrounding asphalt until it is heated to the preset temperature;

[0016] S6: Add asphalt regeneration agent and then add new materials to repair the road surface.

[0017] Furthermore, in the trenchless anti-settling manhole cover height difference regulation method, the data collection includes:

[0018] Manhole cover settlement: Use tools such as a level and laser rangefinder to measure the height difference between the manhole cover and the surrounding road surface, and record the settlement at different locations.

[0019] Subsidence area: measure the scope of the subsidence area and draw a sketch of the subsidence area;

[0020] Asphalt pavement condition: observe the pavement condition, assess the degree of pavement aging, and take samples for indoor testing to determine the asphalt penetration, softening point, and ductility.

[0021] Underground combustible gas: Use a combustible gas detector to measure the concentration of methane and hydrogen sulfide gas in the well;

[0022] Manhole cover size: Measure the diameter of the inner tube and flange of the manhole cover, and select the appropriate high-frequency heating coil and limit steel mold.

[0023] Furthermore, the trenchless anti-subsidence manhole cover height difference treatment method includes, in S2: predicting the change of the combustible concentration in the manhole cover through time series;

[0024] Time series decomposition: decompose historical gas concentration data into trend terms, seasonal terms, and residual terms;

[0025] External factor regression: Use regression model to establish the relationship between external factors and residual terms;

[0026] Hybrid forecast: Combine the results of trend item forecast, seasonal item forecast and external factor regression forecast to obtain the final gas concentration forecast;

[0027] Time series decomposition:

[0028] Y(t)=T(t)+S(t)+R(t);

[0029] Where Y(t) is the gas concentration at time t, T(t) is the trend term at time t, S(t) is the seasonal term at time t, and R(t) is the residual term at time t;

[0030] External factors regression:

[0031] R(t)=β0+β1*x1(t)+β2*x2(t)+...+β n x n (t)+ε(t);

[0032] Among them, x1(t),x2(t),...,x n (t) is the external factor at time t, β1,β2,...,β n is the regression coefficient, ε(t) is the error term;

[0033] Hybrid Forecast:

[0034] Y(t+h)=T(t+h)+S(t+h)+R(t+h);

[0035] Where Y(t+h) is the gas concentration at time t+h, T(t+h) is the trend term at time t+h, S(t+h) is the seasonal term at time t+h, and R(t+h) is the residual term at time t+h.

[0036] Furthermore, the trenchless anti-subsidence manhole cover height difference treatment method includes in S3: quickly softening the asphalt around the manhole cover by high-frequency electromagnetic induction heating to reduce the adhesion between the manhole cover and the road surface; wherein the fuzzy PID control includes:

[0037] Determine input and output:

[0038] Input: Deviation e = set temperature - actual temperature, deviation change rate ec = (et - et - 1) / Δt;

[0039] Output: PID parameter adjustment ΔKp, ΔKi, ΔKd;

[0040] Fuzzification: fuzzify the input variables, i.e. map them to fuzzy sets;

[0041] Establish fuzzy rules: establish a fuzzy rule base to describe the relationship between input and output;

[0042] If e is positive and large and ec is zero, then ΔKp is positive and large, ΔKi is negative and small, and ΔKd is zero;

[0043] Fuzzy reasoning: Based on the fuzzy rule base and the fuzzy values ​​of the input variables, fuzzy reasoning is performed to obtain the fuzzy values ​​of the output variables.

[0044] Defuzzification: Defuzzify the fuzzy value of the output variable to obtain the adjustment amount of PID parameters ΔKp, ΔKi, ΔKd;

[0045] Update PID parameters: Update PID parameters using adjustment values:

[0046] Kp=Kp+ΔKp;

[0047] Ki=Ki+ΔKi;

[0048] Kd=Kd+ΔKd;

[0049] Calculate the control quantity: Use the updated PID parameters to calculate the control quantity:

[0050] Control quantity = Kp*e+Ki*∫edt+Kd*de / dt;

[0051] Repeat the above steps: Repeat the above steps until the wellhead asphalt is softened.

[0052] Furthermore, in the trenchless anti-settling manhole cover height difference regulation method, the heat conduction model includes:

[0053] Radiative heat transfer:

[0054] q_rad=ε*σ*(T_heater^4-T_surface^4);

[0055] Where q_rad is the radiative heat flux, ε is the emissivity of the heating plate, σ is the Stefan-Boltzmann constant, T_heater is the surface temperature of the heating plate, and T_surface is the surface temperature of the asphalt pavement. Radiative heat transfer is proportional to the fourth power of temperature.

[0056] Heat conduction inside asphalt:

[0057]

[0058] ρ is the density of asphalt mixture (kg / m 3 ), c is the specific heat capacity of asphalt mixture, t is time, x is depth, is the partial derivative of temperature with respect to time, is the second-order partial derivative of temperature with respect to depth, and q is the heat source term;

[0059] During the asphalt heating process, q mainly comes from radiation heat transfer, and boundary conditions are used to introduce radiation heat flux into the heat conduction equation;

[0060]

[0061] It represents the heat flux transferred from the inside of the pavement to the surface through heat conduction, and the negative sign indicates that heat flows from the high-temperature area to the low-temperature area; q_rad represents the radiation heat flux; h represents the surface heat transfer coefficient, which describes the efficiency of heat exchange between the pavement surface and the surrounding air through convection; T_surface represents the temperature of the asphalt pavement surface; and T_ambient represents the ambient temperature.

[0062] Furthermore, the trenchless anti-subsidence manhole cover height difference treatment method performs gradient heating strategy optimization based on the heat conduction model, and predicts the heating time based on a fixed heating distance;

[0063] The gradient heating strategy includes:

[0064] To find the best gradient heating strategy, a mathematical model was established to describe the temperature distribution between the upper and lower layers of the asphalt pavement:

[0065] The one-dimensional unsteady heat conduction equation can approximately describe the change of pavement temperature with time and depth:

[0066]

[0067] ρ is the density of asphalt, c is the specific heat capacity of asphalt, T(x, t) is the temperature at depth x and time t, k is the thermal conductivity of asphalt, and Q(x, t) is the heat source intensity at depth x and time t;

[0068] Objective function: The optimization goal is to minimize the heating time and temperature error while satisfying the constraints;

[0069] J=w_t*t_heating+w_e*∫0L(T(x,t_heating)-T_target(x)) 2 dx;

[0070] Where: t_heating is the heating time, T_target(x) is the target temperature at depth x, w_t and w_e are weight coefficients used to balance the heating time and temperature error, and L is the road surface depth;

[0071] Constraints: Maximum surface temperature constraint: T(0, t) ≤ T_max;

[0072] Target temperature range of each layer: T_min(x)≤T(x, t_heating)≤T_max(x).

[0073] A trenchless anti-settling manhole cover height difference regulation system is applied to any of the trenchless anti-settling manhole cover height difference regulation methods described above, the system comprising:

[0074] Wellhead safety and explosion-proof unit: includes high-temperature resistant rubber airbags, screw nuts, plane bearings, upper and lower steel plates and inner cylinder, aerogel blanket insulation layer, and combustible gas monitoring module, used to isolate combustible gases in the well and prevent heat leakage;

[0075] High-frequency heating unit: It consists of a high-frequency electromagnetic induction coil and an infrared temperature control system. It is used to quickly and directionally heat the anti-subsidence manhole cover to 160-180°C. The heat is transferred to the asphalt pavement interface with the anti-subsidence manhole cover at a depth of 10-20mm, so that the asphalt bonded to the manhole cover reaches a softening temperature of 100°C. The temperature of the inner cylinder of the anti-subsidence manhole cover is controlled to be ≤180°C, and the temperature of the flange is 120°C.

[0076] Lifting device unit: including screw jack, I-beam support frame and L-shaped hook plate, used for non-destructive separation of anti-settlement manhole cover and asphalt pavement;

[0077] Asphalt in-situ heating unit: It consists of a modular graphene far-infrared heating plate and a PID temperature control system, supports gradient heating control, and is equipped with an aluminum foil reflective layer and an aerogel blanket insulation layer to improve energy efficiency.

[0078] Furthermore, in the described trenchless anti-subsidence manhole cover height difference control system, the induction coil of the high-frequency heating unit is a spiral ring structure, the inner diameter of which matches the diameter of the anti-subsidence manhole cover limiting cylinder, and the electromagnetic power is dynamically adjusted through the PID algorithm to achieve precise decoupling of the anti-subsidence manhole cover-asphalt interface.

[0079] Furthermore, in the described trenchless anti-subsidence manhole cover height difference improvement system, the modular graphene far-infrared heating plate of the asphalt in-situ heating unit is spliced ​​into a heating trolley by two sub-units, the heating plate is fixed to the mobile trolley with a snap, and each sub-unit is equipped with an independent temperature control circuit, and the PID algorithm dynamically adjusts the power; it is wrapped with an aerogel blanket to reduce heat loss.

[0080] The beneficial effects of the present invention are:

[0081] The present invention proposes a combination of high-frequency electromagnetic induction heating and far-infrared in-situ heating: it is used to quickly and directionally heat the manhole cover body, soften the asphalt around the manhole cover, reduce the adhesion between the manhole cover and the road surface, and facilitate the lossless separation of the manhole cover; far-infrared heating is used to heat the asphalt around the manhole cover opening, realize in-situ thermal regeneration and repair of the asphalt pavement, and improve the repair quality.

[0082] The trenchless technology proposed in this invention can speed up road repair time, shorten single-point operation time to less than 3 hours, reduce the impact on traffic, and save 40% of costs and reduce carbon emissions by 75% compared to traditional excavation repair methods.

[0083] The heat conduction model proposed in the present invention predicts the internal temperature distribution of asphalt, optimizes the heating time and temperature, achieves efficient heating and avoids asphalt aging. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] Figure 1 It is a flow chart of a trenchless anti-subsidence manhole cover height difference regulation method;

[0085] Figure 2 This is a cross-sectional view of the sealing structure of the wellhead explosion-proof unit;

[0086] Figure 3 is a cross-sectional view of the wellhead air barrier airbag structure 200 in an embodiment;

[0087] Figure 4 It is the layout diagram of the high-frequency electromagnetic induction coil;

[0088] Figure 5 This is a schematic diagram of the anti-subsidence manhole cover lifting device unit;

[0089] Figure 6 It is a schematic diagram of a graphene far-infrared heating plate;

[0090] Figure 7 It is the graphene heating plate trolley module intention;

[0091] Figure 8 is a schematic diagram of construction steps in one embodiment.

[0092] Among them, anti-subsidence manhole cover-100: 101-anti-subsidence manhole cover inner tube, 102-anti-subsidence manhole cover flange, 103-anti-subsidence manhole cover, 104-reinforced concrete manhole ring;

[0093] Wellhead air barrier airbag structure-200: 201-airbag (outer diameter 650mm), 202-airbag upper steel plate (inner diameter 550mm*thickness 5mm), 203-airbag upper inner tube, 204-plane bearing (25*52*18mm), 205-hexagonal nut 31*22mm, 206-screw 207 airbag lower steel plate (inner diameter 550mm*thickness 5mm), 208 airbag lower inner cylinder; by tightening 205, 202 and 207 move towards each other and compress 201 airbag, 207 and 203 constrain 201 to expand outward;

[0094] High frequency heating unit - 300: 301-coil, 302-insulated handle for holding;

[0095] Pavement structure - 600: 601-Asphalt pavement upper layer (usually modified asphalt), 60-Asphalt pavement lower layer (usually ordinary asphalt), 603-Cement stabilized upper base, 604-Cement stabilized lower base, 605-Graded crushed stone cushion, 60-Soil subgrade;

[0096] Lifting device-400: 401-lifting plate, 402-lifting ring 403-8# I-steel, 404-screw jack 16t;

[0097] Far-infrared heating plate unit-500: 501-far-infrared heating plate, 5012-heating plate support beam, 5011-insulating ceramic terminal, 503-trolley, 5031-folding universal wheel; 5021-far-infrared emitted heat, 5022-heat emitted but not absorbed by the road surface, 5023-heat absorbed by the road surface, 5024-aerogel blanket to constrain heat, 504-aerogel blanket heat insulation cover. DETAILED DESCRIPTION

[0098] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0099] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the described features. In the description of this application, "plurality" means two or more, unless otherwise specifically specified.

[0100] In the description of this application, the term "for example" is used to mean "used as an example, illustration or explanation". Any embodiment described as "for example" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is given to enable any person skilled in the art to implement and use the present invention. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art will recognize that the present invention can be implemented without using these specific details. In other examples, well-known structures and processes will not be elaborated in detail to avoid obscuring the description of the present invention with unnecessary details. Therefore, the present invention is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles and features disclosed in this application.

[0101] In one embodiment, a trenchless anti-settling manhole cover height difference control method includes the following steps:

[0102] S1: Conduct on-site surveys and data collection, and prepare corresponding tools based on the collected data;

[0103] S2: Install a wellhead air barrier to monitor the concentration of combustibles in the manhole cover in real time and predict the time when it reaches the safety threshold;

[0104] S3: After the combustible gas concentration reaches the safety threshold, a high-frequency coil is installed and the fuzzy PID control is used to heat and soften the wellhead asphalt.

[0105] S4: Physical separation of manhole covers;

[0106] S5: Use far-infrared heating to heat the asphalt around the manhole cover, and build a heat conduction model to predict the temperature of the surrounding asphalt until it is heated to the preset temperature;

[0107] S6: Add asphalt regeneration agent and then add new materials to repair the road surface.

[0108] The data collection includes:

[0109] Manhole cover settlement: Use tools such as a level and laser rangefinder to measure the height difference between the manhole cover and the surrounding road surface, and record the settlement at different locations.

[0110] Subsidence area: measure the scope of the subsidence area and draw a sketch of the subsidence area;

[0111] Asphalt pavement condition: observe the pavement condition, assess the degree of pavement aging, and take samples for indoor testing to determine the asphalt penetration, softening point, and ductility.

[0112] Underground combustible gas: Use a combustible gas detector to measure the concentration of methane and hydrogen sulfide gas in the well;

[0113] Manhole cover size: Measure the diameter of the inner tube and flange of the manhole cover, and select the appropriate high-frequency heating coil and limit steel mold.

[0114] In one embodiment, S2 includes: predicting the change of the concentration of combustibles in the manhole cover through time series;

[0115] Time series decomposition: decompose historical gas concentration data into trend terms, seasonal terms, and residual terms;

[0116] External factor regression: Use regression model to establish the relationship between external factors and residual terms;

[0117] Hybrid forecast: Combine the results of trend item forecast, seasonal item forecast and external factor regression forecast to obtain the final gas concentration forecast;

[0118] Time series decomposition:

[0119] Y(t)=T(t)+S(t)+R(t);

[0120] Where Y(t) is the gas concentration at time t, T(t) is the trend term at time t, S(t) is the seasonal term at time t, and R(t) is the residual term at time t;

[0121] External factors regression:

[0122] R(t)=β0+β1*x1(t)+β2*x2(t)+...+β n x n (t)+ε(t);

[0123] Among them, x1(t),x2(t),...,x n (t) is the external factor at time t, β1,β2,...,β n is the regression coefficient, ε(t) is the error term;

[0124] Hybrid Forecast:

[0125] Y(t+h)=T(t+h)+S(t+h)+R(t+h);

[0126] Where Y(t+h) is the gas concentration at time t+h, T(t+h) is the trend term at time t+h, S(t+h) is the seasonal term at time t+h, and R(t+h) is the residual term at time t+h.

[0127] In this embodiment, when performing manhole cover maintenance operations, especially those involving heating, combustible gases (such as methane) may be present underground, and safety issues are of paramount importance. Relying solely on real-time detection may have a lag and cannot predict concentration changes in advance. Therefore, using time series prediction technology, gas concentrations over a period of time can be predicted, allowing more effective safety measures to be taken. For example, the methane concentration in the well may vary.

[0128] Case 1: The amount of methane is fixed, and we just need to wait for it to diffuse and overflow;

[0129] Case 2: The amount of methane is not fixed and is constantly leaking out at a certain rate.

[0130] In case 1, a time series model is used to predict the time of the release. The time series model analyzes the rate of decrease in methane concentration in the past and uses this rate to predict the future. For example, if the methane concentration has decreased by an average of 0.1% per minute over the past 10 minutes, the model may predict a similar decrease in the next period.

[0131] According to scenario 2, there is a continuous methane leakage source in the well, and methane is leaking out at a relatively constant rate. This will cause the methane concentration at the wellhead to remain at a high level for a period of time, and may even slowly increase;

[0132] In this case, the time series model should not only predict the concentration, but more importantly, the trend of concentration change. If the model predicts that methane concentration will increase at a rate of 0.05% per minute, then the risks associated with this upward trend need to be carefully assessed.

[0133] In one embodiment, S3 includes: rapidly softening the asphalt around the manhole cover by high-frequency electromagnetic induction heating to reduce the adhesion between the manhole cover and the road surface; wherein the fuzzy PID control includes:

[0134] Determine input and output:

[0135] Input: Deviation e = set temperature - actual temperature, deviation change rate ec = (et - et - 1) / Δt;

[0136] Output: PID parameter adjustment ΔKp, ΔKi, ΔKd;

[0137] Fuzzification: fuzzify the input variables, i.e. map them to fuzzy sets;

[0138] Establish fuzzy rules: establish a fuzzy rule base to describe the relationship between input and output;

[0139] If e is positive and large and ec is zero, then ΔKp is positive and large, ΔKi is negative and small, and ΔKd is zero;

[0140] Fuzzy reasoning: Based on the fuzzy rule base and the fuzzy values ​​of the input variables, fuzzy reasoning is performed to obtain the fuzzy values ​​of the output variables.

[0141] Defuzzification: Defuzzify the fuzzy value of the output variable to obtain the adjustment amount of PID parameters ΔKp, ΔKi, ΔKd;

[0142] Update PID parameters: Update PID parameters using adjustment values:

[0143] Kp=Kp+ΔKp;

[0144] Ki=Ki+ΔKi;

[0145] Kd=Kd+ΔKd;

[0146] Calculate the control quantity: Use the updated PID parameters to calculate the control quantity:

[0147] Control quantity = Kp*e+Ki*∫edt+Kd*de / dt;

[0148] Repeat the above steps: Repeat the above steps until the wellhead asphalt is softened.

[0149] In a specific embodiment, it is necessary to quickly soften the asphalt around the manhole cover in this scenario. The target temperature is set to 170°C (±5°C fluctuation range), and the heat conduction depth is controlled to 10-20mm, while avoiding overheating of the manhole cover itself (≤180°C).

[0150] enter:

[0151] Deviation e = set temperature (170°C) - actual temperature (surface temperature of the manhole cover monitored in real time by an infrared thermometer, for example, 150°C);

[0152] Deviation change rate ec = (et - et - 1) / Δt;

[0153] et: the temperature deviation at the current moment (e.g., 170°C - 150°C = 20°C);

[0154] et-1: temperature deviation at the previous moment (for example, if the temperature at the previous moment is 145°C, then et-1 = 170°C - 145°C = 25°C);

[0155] Δt: time interval (e.g., 1 second);

[0156] ec = (20°C - 25°C) / 1 second = -5°C / second;

[0157] Output:

[0158] PID parameter adjustment: ΔKp, ΔKi, ΔKd (these adjustment amounts will affect the power output of the high-frequency heating unit);

[0159] Fuzzification:

[0160] Map the input variables (e and ec) to fuzzy sets; for example, as shown in Table 1:

[0161] Fuzzy set name Deviation (E) range (℃) Deviation change rate (EC) range (℃ / second) Negative Big (NB) e<-10 ec<-5 Negative Middle (NM) -10≤e<-3 -5≤ec<-1 Negative Small (NS) -3≤e<0 -1≤ec<0 Zero (ZE) -0.5≤e≤0.5 -0.1≤ec≤0.1 Small (PS) 0<e≤3 0<ec≤1 Middle (PM) 3<e≤10 1<ec≤5 CP Group (PB) e>10 ec>5

[0162] Table 1

[0163] Example: For e=20°C and ec=-5°C / second calculated above, e belongs to the "positive large (PB)" fuzzy set and ec belongs to the "negative medium (NM)" fuzzy set.

[0164] The fuzzy rule base (partial examples) is shown in Table 2:

[0165] E EC ΔKP ΔKI ΔKD PB PB PS NB ZE PB PM PS NM ZE PB PS PM NS PS PM PB PS NM ZE ... ... ... ... ... ZE ZE ZE ZE ZE ... ... ... ... ... NB NB NS PB ZE

[0166] Table 2

[0167] Explanation: "If e is positive large (PB) and ec is negative medium (NM), then ΔKp is positive small (PS), ΔKi is negative medium (NM), and ΔKd is zero (ZE)"

[0168] Here, PS, NS, ZE, etc. also need to be quantified, for example, PS can be +0.1, NS is -0.1, ZE is 0, etc.

[0169] Fuzzy reasoning: Determine the fuzzy value of the output variable based on the fuzzy set to which the input variable belongs and the fuzzy rule base.

[0170] Example: Based on the above example (e is PB, ec is NM), we can see from the table that ΔKp is PS, ΔKi is NM, and ΔKd is ZE.

[0171] Defuzzification: Convert the fuzzy values ​​of the output variables to concrete numerical values. This is usually done using the centroid method or other defuzzification methods.

[0172] Example: Assume that after quantization, PS corresponds to +0.1, NM corresponds to -0.05, and ZE corresponds to 0.

[0173] Update PID parameters:

[0174] Kp = Kp + ΔKp (e.g., Kp = 0.5 + 0.1 = 0.6)

[0175] Ki=Ki+ΔKi (for example, Ki=0.01+(-0.05)=-0.04)

[0176] Kd = Kd + ΔKd (e.g., Kd = 0.2 + 0 = 0.2)

[0177] The initial Kp, Ki, and Kd values ​​need to be pre-set based on experience or experiments.

[0178] Calculate the control quantity:

[0179] Control quantity = Kp*e+Ki*∫edt+Kd*de / dt

[0180] The integral term ∫edt can be approximated by the sum of the accumulated deviations.

[0181] The differential term de / dt can be approximately calculated using (et-et-1) / Δt.

[0182] Example:

[0183] Assume ∫edt = 50 (cumulative deviation)

[0184] de / dt=(20-25) / 1=-5

[0185] Control amount = 0.6*20+(-0.04)*50+0.2*(-5)=12-2-1=9

[0186] The control quantity is mapped to the power output:

[0187] The calculated control amount is mapped to the power output percentage of the high frequency heating unit. For example, a control amount of 9 corresponds to a power output of 50%.

[0188] Repeat the above steps:

[0189] At regular intervals (e.g., 1 second), the above PID control steps are repeated, and the power output of the high-frequency heating unit is dynamically adjusted according to the actual temperature deviation until the surface temperature of the manhole cover stabilizes at around 170°C.

[0190] In another embodiment, the PID control strategy can also be applied to far-infrared heating in subsequent steps.

[0191] In one embodiment, the heat conduction model includes:

[0192] Radiative heat transfer:

[0193] q_rad=ε*σ*(T_heater^4-T_surface^4);

[0194] Where q_rad is the radiative heat flux, ε is the emissivity of the heating plate, σ is the Stefan-Boltzmann constant, T_heater is the surface temperature of the heating plate, and T_surface is the surface temperature of the asphalt pavement. Radiative heat transfer is proportional to the fourth power of temperature.

[0195] Heat conduction inside asphalt:

[0196]

[0197] ρ is the density of asphalt mixture (kg / m 3 ), c is the specific heat capacity of asphalt mixture, t is time, x is depth, is the partial derivative of temperature with respect to time, is the second-order partial derivative of temperature with respect to depth, and q is the heat source term;

[0198] During the asphalt heating process, q mainly comes from radiation heat transfer, and boundary conditions are used to introduce radiation heat flux into the heat conduction equation;

[0199]

[0200] It represents the heat flux transferred from the inside of the pavement to the surface through heat conduction, and the negative sign indicates that heat flows from the high-temperature area to the low-temperature area; q_rad represents the radiation heat flux; h represents the surface heat transfer coefficient, which describes the efficiency of heat exchange between the pavement surface and the surrounding air through convection; T_surface represents the temperature of the asphalt pavement surface; and T_ambient represents the ambient temperature.

[0201] Based on the heat conduction model, a gradient heating strategy is optimized to predict the heating time based on a fixed heating distance.

[0202] The gradient heating strategy includes:

[0203] To find the best gradient heating strategy, a mathematical model was established to describe the temperature distribution between the upper and lower layers of the asphalt pavement:

[0204] The one-dimensional unsteady heat conduction equation can approximately describe the change of pavement temperature with time and depth:

[0205]

[0206] ρ is the density of asphalt, c is the specific heat capacity of asphalt, T(x, t) is the temperature at depth x and time t, k is the thermal conductivity of asphalt, and Q(x, t) is the heat source intensity at depth x and time t;

[0207] Objective function: The optimization goal is to minimize the heating time and temperature error while satisfying the constraints;

[0208] J=w_t*t_heating+w_e*∫0L(T(x,t_heating)-T_target(x)) 2 dx;

[0209] Where: t_heating is the heating time, T_target(x) is the target temperature at depth x, w_t and w_e are weight coefficients used to balance the heating time and temperature error, and L is the road surface depth;

[0210] Constraints: Maximum surface temperature constraint: T(0, t) ≤ T_max;

[0211] Target temperature range of each layer: T_min(x)≤T(x, t_heating)≤T_max(x).

[0212] In a specific embodiment, it is explained based on some existing data:

[0213] Asphalt pavement parameters:

[0214] Density (ρ): 2400 kg / m 3 (Common asphalt mixture density);

[0215] Specific heat capacity (c): 920 J / (kg·K) (Typical specific heat capacity of asphalt mixture);

[0216] Thermal conductivity (k): 1.2 W / (m·K) (Thermal conductivity of asphalt mixture);

[0217] Initial temperature: 25 °C (Ambient temperature);

[0218] Pavement depth (L): 0.05 m (5 cm);

[0219] Target temperature of the upper layer (0 - 2 cm): 160 °C (Modified asphalt target);

[0220] Target temperature of the lower layer (2 - 5 cm): 140 °C (Modified asphalt target);

[0221] T_target(x): A function that describes the target temperature at different depths x. For example, it can be defined piecewise as follows:

[0222] If 0 ≤ x ≤ 0.02 m: T_target(x) = 160 + 273.15 (converted to Kelvin);

[0223] If 0.02 m < x ≤ 0.05 m: T_target(x) = 140 + 273.15 (converted to Kelvin);

[0224] Heating equipment parameters (Graphene far-infrared heating panel):[[ID=三十三]]

[0225] Surface temperature of the heating panel (T_heater): Adjustable, for example, in the range of 250 °C - 400 °C;

[0226] Emissivity (ε): 0.9 (Typical emissivity of graphene coating);

[0227] Surface heat transfer coefficient (h): 10 W / (m 2 ·K) (In the case of natural convection);

[0228] Ambient temperature (T_ambient): 25 °C;

[0229] Other parameters:

[0230] Stefan-Boltzmann constant (σ): 5.67x10 -8 W / (m 2 ·K 4 );

[0231] Maximum surface temperature constraint (T_max): 200°C (to prevent asphalt aging);

[0232] Calculate the radiation heat flux through the heat conduction model;

[0233] Using the radiation heat transfer formula:

[0234] Assume that the heating plate temperature (T_heater) is 350°C (623.15K) and the asphalt surface temperature (T_surface) is 25°C (298.15K).

[0235] q_rad=0.9*5.67x10 -8 *(623.15 4 -298.15 4 )≈7800W / m 2

[0236] Numerical simulation of temperature distribution inside asphalt;

[0237] Using the one-dimensional unsteady heat conduction equation:

[0238] Where Q(x,t) is the heat source term, which mainly comes from radiation heat transfer;

[0239] using numerical methods (e.g., finite difference methods) to solve the equation;

[0240] Discretize the asphalt pavement into several small intervals along the depth direction (for example, one node per millimeter);

[0241] Discretize time into small time steps (e.g., one step per second);

[0242] Use difference schemes to approximate partial derivatives and transform partial differential equations into a system of algebraic equations;

[0243] At each time step, a system of algebraic equations is solved to update the temperature value at each node.

[0244] Boundary conditions:

[0245] x=0 (road surface):

[0246] x = L (bottom of the road): adiabatic boundary condition (assuming that the heat loss at the bottom is small), that is,

[0247] Initial conditions: The temperature of all nodes is the initial temperature of 25℃.

[0248] Optimize gradient heating strategy;

[0249] Objective function:

[0250] J=w_t*t_heating+w_e*∫0L(T(x,t_heating)-T_target(x)) 2 dx

[0251] Set the weight coefficients, for example, w_t = 0.6, w_e = 0.4 (giving more importance to heating time, but also taking temperature accuracy into consideration).

[0252] Constraints:

[0253] T(0,t)≤200+273.15 (surface maximum temperature constraint)

[0254] T_min(x)≤T(x,t_heating)≤T_max(x) (target temperature range of each layer)

[0255] For example, the target temperature range of the upper layer is: 155℃-165℃

[0256] For example, the target temperature range of the following layer is: 135℃-145℃

[0257] Parameterized Heating Strategies: Here, only the heating time (t_heating) is optimized, assuming a fixed heating plate temperature. More complex strategies can be parameterized, such as a time-varying heating plate temperature.

[0258] Select an optimization algorithm: You can use gradient descent, genetic algorithms, and other optimization algorithms. Here, we simplify and use an exhaustive method. For example, within the range of 1 minute to 30 minutes, try a heating time every 30 seconds.

[0259] Numerical simulation: For each heating time, a heat conduction model is used to perform numerical simulation and obtain T(x,t_heating).

[0260] Calculate the objective function: Calculate the value of the objective function J based on the numerical simulation results.

[0261] Select the optimal solution: Select the heating time that minimizes the objective function J; at the same time, check whether the constraints are met; if all constraints are met, the solution is the optimal solution.

[0262] In one embodiment, a trenchless anti-settling manhole cover height difference regulation system is applied to any of the trenchless anti-settling manhole cover height difference regulation methods described above, the system comprising:

[0263] Wellhead safety and explosion-proof unit: includes high-temperature resistant rubber airbags, screw nuts, plane bearings, upper and lower steel plates and inner cylinder, aerogel blanket insulation layer, and combustible gas monitoring module, used to isolate combustible gases in the well and prevent heat leakage;

[0264] High-frequency heating unit: It consists of a high-frequency electromagnetic induction coil and an infrared temperature control system. It is used to quickly and directionally heat the anti-subsidence manhole cover to 160-180°C. The heat is transferred to the asphalt pavement interface with the anti-subsidence manhole cover at a depth of 10-20mm, so that the asphalt bonded to the manhole cover reaches a softening temperature of 100°C. The temperature of the inner cylinder of the anti-subsidence manhole cover is controlled to be ≤180°C, and the temperature of the flange is 120°C.

[0265] Lifting device unit: including screw jack, I-beam support frame and L-shaped hook plate, used for non-destructive separation of anti-settlement manhole cover and asphalt pavement;

[0266] Asphalt in-situ heating unit: It consists of a modular graphene far-infrared heating plate and a PID temperature control system, supports gradient heating control, and is equipped with an aluminum foil reflective layer and an aerogel blanket insulation layer to improve energy efficiency.

[0267] In this embodiment, far-infrared heating uses a graphene far-infrared heating plate, and electrical energy is directly converted into far-infrared rays, with almost no energy waste. It saves 30-50% of electricity compared to gas heating and is easy to achieve precise temperature control.

[0268] Furthermore, the induction coil of the high-frequency heating unit is a spiral ring structure, the inner diameter of which matches the diameter of the anti-subsidence manhole cover limiting cylinder. The electromagnetic power is dynamically adjusted through the PID algorithm to achieve precise decoupling of the anti-subsidence manhole cover-asphalt interface.

[0269] Furthermore, the combustible gas monitoring module of the wellhead safety and explosion-proof unit is linked to the rubber airbag. When it is detected that the methane concentration exceeds a threshold, the air compressor is automatically triggered to replenish the pressure of the airbag and supply air to the wellhead.

[0270] Furthermore, the modular graphene far-infrared heating plate of the asphalt in-situ heating unit is spliced ​​into a heating trolley by two sub-units. The heating plate is fixed to the mobile trolley with a snap, and each sub-unit is equipped with an independent temperature control circuit. The PID algorithm dynamically adjusts the power; it is wrapped with an aerogel blanket to reduce heat loss.

[0271] In a specific construction embodiment;

[0272] Step 1: Preparation.

[0273] 1) Investigate and number the defects of manhole covers on the road surface, mark the asphalt pavement boundary around the manhole covers that need repair on site, measure and record the settlement and volume around the manhole covers, and the height difference between the manhole covers and the road surface;

[0274] 2) Handle the application procedures for the maintenance of anti-subsidence manhole covers;

[0275] 3) After the procedures are approved, organize the corresponding road maintenance workers and provide pre-job training;

[0276] 4) Organize 380v / 100KW vehicle-mounted diesel generator, air-isolating airbags, high-frequency equipment and coils, graphene far-infrared heating trolley, anti-subsidence manhole cover lifting device, asphalt hot material, 13t double steel wheels, adjustable diameter limit steel molds, temporary safety isolation guardrails, traffic reflective cones, lane occupation warning signs, traffic signs, etc.

[0277] Step 2: Installation of temporary fences in the work area (estimated time: 30 minutes);

[0278] 1) According to the plan approved by the municipal management unit, temporary road barriers will be installed, and traffic warning signs such as traffic signs will be set up 50 meters in front of the vehicle entering the work area;

[0279] 2) Install sight-inducing day and night flashing lights on the outside of the temporary enclosure;

[0280] Step 3: Install the Wellhead Air Barrier-200 (estimated time: 5 minutes)

[0281] 1) Based on the investigated data on the damage of anti-subsidence manhole covers, number and review the measurement data on site;

[0282] 2) Mark the perimeter of the settlement on the asphalt pavement;

[0283] 3) Open the anti-settling manhole cover 103 and apply a circle of silicone glue on the inside of the wellhead. The glue application area should be more than 500mm away from the bottom of the anti-settling manhole cover inner tube 101.

[0284] 4) Install the air barrier airbag 200. Use an electric wrench to drive the 31*22 nut 205 downward along the screw 206 of the airbag 22. The 25*52*18 plane bearing 204 forces the airbag upper steel plate 202, the airbag upper inner cylinder 203, and the airbag lower steel plate 207, and the airbag lower inner cylinder to squeeze each other, forcing the airbag 201 to expand toward the wellhead. 203 / 208 restrain the airbag from expanding and displacing inward.

[0285] 5) After the airbag 201 is inflated, the friction between it and the inner wall of the wellhead is greater than 50 kg. Check that the airbag 201 can bear a weight of 50 kg. Apply another circle of silicone glue along the contact point between 201 and the well body.

[0286] 6) Laying a 10 mm thick aerogel blanket on the air barrier airbag device 200 for heat insulation;

[0287] 7) Use a blower to supply air to the wellhead and place a combustible gas monitor to monitor whether there is any combustible gas escaping from the well;

[0288] Step 4: Install the High-Frequency Coil-300 (estimated time: 5 minutes)

[0289] 1) Ensure that no flammable gas escapes from the wellhead;

[0290] 2) Place the entire high-tech coil assembly 300 inside the wellhead

[0291] 3) The outer diameter of the inner cylinder high-frequency coil 301 is 50mm smaller than the inner diameter of the anti-sinking manhole cover inner cylinder 101; the high-frequency coil 302 is the anti-sinking manhole cover flange heating coil, with an outer diameter of 750mm, which heats the flange in a directional and rapid manner;

[0292] Step 5: Energize the coil to heat the anti-settling manhole cover (estimated time: 5 minutes)

[0293] 1) Turn on the high-frequency output device for 60 seconds;

[0294] 2) The infrared thermometer monitors the temperature of the inner tube 101 of the manhole cover. The temperature must not exceed 180°C. If it exceeds 180°C, the high-frequency output will be immediately turned off.

[0295] 3) The infrared thermometer monitors the temperature of the anti-settling manhole cover flange 102. When the temperature reaches 120°C, the high-frequency output can be stopped;

[0296] 4) The purpose of rapid heating is to soften the asphalt 601 / 602 in contact with the dustproof manhole cover 101 / 102 quickly, with heat conduction not exceeding 10-20mm, and the lifting process of 101 will not damage the original wellhead asphalt pavement;

[0297] Step 6: Install the manhole cover lifting device-400 (estimated time 10 minutes)

[0298] 1) Place the screw jack 404 and put the lifting ring 402 on the I-beam 403; place the I-beam 403 on the jack 404;

[0299] 2) Hook the lower end of 101 on the hanging plate 401, and hook the upper end of 401 on 402;

[0300] 3) Shake 404 to raise the top column of 404 and lift the anti-settling manhole cover;

[0301] 4) There are two sets of lifting devices 400, four hook points, and four 404s are lifted synchronously;

[0302] 5) The anti-subsidence manhole cover 101 / 102 is decoupled from the asphalt pavement 601 / 602;

[0303] Step 7: Install the adjustable diameter limit steel mold-700 (estimated time 10 minutes)

[0304] 1) After the anti-settling manhole cover is removed, the wellhead adjustable diameter limit steel mold-700 is installed to prevent the heated asphalt edge of the wellhead from collapsing and falling onto the airbag device-200 at the wellhead;

[0305] 2) Use a pick to buckle out the four support ears and adjust the diameter of the limit steel membrane to match the anti-settling manhole cover -101; the steel mold cover is 10cm lower than the asphalt around the wellhead;

[0306] Step 8: Graphene Far Infrared Heating Cart-500 in Place (estimated time: 10 minutes)

[0307] 1) Move the far-infrared heating trolley 500 to the designated position;

[0308] 2) Generally, the asphalt settlement around the anti-subsidence manhole cover is within the range of 1500*1500mm (the anti-subsidence manhole cover of the original newly paved asphalt pavement is installed by traditional method 1: reverse excavation method, and the asphalt around the manhole cover is manually compacted, resulting in insufficient compaction; traditional method 2: Matsuura installs the anti-subsidence manhole cover simultaneously, the adjustment time is too long, the compaction temperature is missed, resulting in insufficient compaction, the bottom asphalt is paved with steel plates at the wellhead, and after the paver passes, the hot asphalt on the wellhead steel plate is dug out. During the rolling process, the roller is eccentric, resulting in the bottom asphalt at the wellhead being sunken, resulting in the wellhead of the upper asphalt being too thick, and the compaction stroke is inconsistent with the road surface thickness, resulting in insufficient compaction). It is equipped with 4 graphene far-infrared heating trolleys 500, which are spliced ​​and arranged;

[0309] 3) The graphene far-infrared heating trolley 500 is composed of a stainless steel trolley 503, a graphene far-infrared heating plate 501, and an aerogel blanket 504.

[0310] 4) The height of the graphene far-infrared heating plate 501 from the asphalt road surface is 30-50 mm; the heating plate trolley should cover a marking range of 200 mm in width;

[0311] Step 9: Turn on the graphene far-infrared heating plate for heating (estimated time: 10 minutes)

[0312] 1) After ensuring that 504 is fully covered, power on the heating plate. The input voltage of the heating plate of this technology is 220V;

[0313] 2) 501 generates heat and conducts far-infrared heat to the road surface through a path 5021 , the original road surface 501 / 602 absorbs energy 5023 , and part of the energy 5022 is reflected, and the aerogel blanket insulates and retains the reflected energy 5024 ;

[0314] Step 10: Detecting the original road surface temperature (estimated time: 10 minutes)

[0315] 1) The graphene far-infrared heating plate is powered on for 10 minutes, the heating trolley is removed 500 degrees, and the temperature of the original asphalt pavement at 0-20mm and 20-50 degrees is measured using a mercury thermometer + an electronic thermometer. When the temperature reaches 160±5°C and 140±5°C respectively, heating can be stopped. The temperature of the graphene far-infrared heating plate is controlled by an independent temperature control unit PID, and the surface temperature shall not exceed 180°C.

[0316] 2) The original pavement should be fully heated. The aggregate should not be damaged during loosening due to insufficient heating temperature, nor should the asphalt be excessively aged due to excessive heating temperature.

[0317] 3) If the specified temperature is not reached after testing, extend the heating time;

[0318] 4) If the original road surface investigation shows that the lower asphalt layer also has insufficient compaction, resulting in a depression in the wellhead road surface, and the base layer is not damaged, extend the heating time and then transfer it to the lower asphalt layer;

[0319] Step 11: Spray the regeneration agent on the original road surface, harrow and mix it (according to Article 8.3.2 and 8.3.3 of the Technical Specification for Highway Asphalt Pavement Regeneration JTG / T5521-2019) (estimated time: 10 minutes)

[0320] 1) After the original road surface is heated to the predetermined temperature, the trolley is removed;

[0321] 2) Spraying regeneration agent;

[0322] 3) Manually rake the original road surface 601 to a depth of 50 cm. The rake depth should be uniform, and the rake depth should gradually change 200 mm inward from the maintenance mark (rake depth 0 mm at the connection point to -50 cm 200 mm inward).

[0323] 4) The raking surface should have a good roughness. After raking, spray the regeneration agent and then raking and mixing. After raking and mixing, the temperature of the loose asphalt material shall not be lower than 130℃. If it is lower than this temperature, use the far infrared heating trolley for secondary heating.

[0324] 5) The surface temperature before scarification should be no higher than 185°C for ordinary asphalt pavement and no higher than 200°C for modified asphalt pavement. The surface temperature after scarification should be no higher than 85°C for ordinary asphalt pavement and no higher than 100°C for modified asphalt pavement.

[0325] Step 12: Add new hot ingredients (10 minutes)

[0326] 1) Calculate the weight of new hot mix asphalt to be added based on the previous pavement survey data, the settlement amount and area of ​​the original pavement;

[0327] 2) Spread evenly and then mix evenly with the recycled material; the hot material temperature should not be lower than 140℃;

[0328] Step 13: Double steel wheel rolling (according to the Technical Specifications for Highway Asphalt Pavement Maintenance JTG5142-2019, Article 6.6.3, and the Technical Specifications for Highway Asphalt Pavement Construction JTGF40-2004, Article 5.7.4) (estimated time: 15 minutes)

[0329] 1) Use double steel wheels to repeatedly compact from the edge to the middle to achieve the required compaction degree. After compaction is completed, spray an appropriate amount of emulsified asphalt on the newly repaired road surface.

[0330] 2) Initially roll 3 times, starting from the marked boundary position, rolling towards the edge of the maintenance range and towards the center, with the steel wheel spanning 200mm from the edge within the maintenance range, and gradually rolling inward; the roller rolls directly across the wellhead limit steel film;

[0331] 3) Re-press 5 times, following the same route as the initial press;

[0332] Step 14: Remove the adjustable diameter limit steel mold-700 (estimated time 5 minutes)

[0333] 1) Reduce the diameter of the limiting steel film, remove the limiting steel film, and manually shovel hot materials to fill the gaps in the steel support ears of the upper paving steel mold. The filling height should be slightly higher than the road surface by 1-2 cm. Use 13t double steel wheels to compact the asphalt material at the filling location of the inspection well mouth: Use a pickaxe to dig out the asphalt at the inspection well mouth to set the position of the hinge axis of the anti-subsidence manhole cover.

[0334] Step 15: Install anti-settling manhole covers, manhole covers and road surface final pressure (estimated time 5 minutes)

[0335] 1) Install the anti-subsidence manhole cover on the inspection well mouth according to the preset hinge axis position of the anti-subsidence manhole cover, manually fill the modified asphalt hot material under the anti-subsidence manhole cover flange and the inner wall of the manhole cover, with a filler thickness of about 1cm; a dedicated person directs the 13t double steel wheel to statically pressurize the anti-subsidence manhole cover to a fixed position, with a rolling speed not exceeding 2km / h, and vibrate the anti-subsidence manhole cover until the road surface is basically level, manually spread fine material to fill the rough surface around the flange, and direct the 13t double steel wheel to vibrate the anti-subsidence manhole cover with high frequency and low amplitude until the height difference between the manhole cover and the road surface is about 0-3mm;

[0336] 2) Finally, press 3-5 times to collect the light until there is no wheel mark;

[0337] Step 16: Open to traffic (estimated time: 30 minutes)

[0338] 1) After the regenerated road surface is rolled, the road surface temperature is less than 50°C, and watering can be used to cool down busy sections;

[0339] 2) Evacuate relevant equipment and remove the wellhead airbag 200;

[0340] 3) Evacuate temporary fences and traffic signs, etc.;

[0341] 4) Open traffic.

[0342] In another embodiment, the time required for each process can be predicted according to the above method, so as to predict the working time before repair, thereby further reducing the occurrence of traffic jams.

[0343] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0344] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A trenchless anti-settlement manhole cover height difference treatment method, characterized in that: The following steps are involved: S1: Conduct on-site surveys and data collection, and prepare corresponding tools based on the collected data; S2: Install a wellhead air barrier to monitor the concentration of combustibles in the manhole cover in real time and predict the time when it reaches the safety threshold; S3: After the combustible gas concentration reaches the safety threshold, a high-frequency coil is installed and the fuzzy PID control is used to heat and soften the wellhead asphalt. S4: Physical separation of manhole covers; S5: Use far-infrared heating to heat the asphalt around the manhole cover, and build a heat conduction model to predict the temperature of the surrounding asphalt until it is heated to the preset temperature; S6: Add asphalt regeneration agent and then add new materials to repair the road surface.

2. A trenchless anti-settling manhole cover height difference treatment method according to claim 1, characterized in that: The data collection includes: Manhole cover settlement: Use tools such as a level and laser rangefinder to measure the height difference between the manhole cover and the surrounding road surface, and record the settlement at different locations. Subsidence area: measure the scope of the subsidence area and draw a sketch of the subsidence area; Asphalt pavement condition: observe the pavement condition, assess the degree of pavement aging, and take samples for indoor testing to determine the asphalt penetration, softening point, and ductility. Underground combustible gas: Use a combustible gas detector to measure the concentration of methane and hydrogen sulfide gas in the well; Manhole cover size: Measure the diameter of the inner tube and flange of the manhole cover, and select the appropriate high-frequency heating coil and limit steel mold.

3. A trenchless anti-settling manhole cover height difference control method according to claim 1, characterized in that: S2 includes: predicting the change of combustible concentration in the manhole cover through time series; Time series decomposition: decompose historical gas concentration data into trend terms, seasonal terms, and residual terms; External factor regression: Use regression model to establish the relationship between external factors and residual terms; Hybrid forecast: Combine the results of trend item forecast, seasonal item forecast and external factor regression forecast to obtain the final gas concentration forecast; Time series decomposition: Y(t)=T(t)+S(t)+R(t); Where Y(t) is the gas concentration at time t, T(t) is the trend term at time t, S(t) is the seasonal term at time t, and R(t) is the residual term at time t; External factors regression: R(t)=β0+β1*x1(t)+β2*x2(t)+...+β n x n (t)+ε(t); Among them, x1(t),x2(t),...,x n (t) is the external factor at time t, β1,β2,...,β n is the regression coefficient, ε(t) is the error term; Hybrid Forecast: Y(t+h)=T(t+h)+S(t+h)+R(t+h); Where Y(t+h) is the gas concentration at time t+h, T(t+h) is the trend term at time t+h, S(t+h) is the seasonal term at time t+h, and R(t+h) is the residual term at time t+h.

4. A trenchless anti-settling manhole cover height difference control method according to claim 1, characterized in that: S3 includes: using high-frequency electromagnetic induction heating to quickly soften the asphalt around the manhole cover and reduce the adhesion between the manhole cover and the road surface; the fuzzy PID control includes: Determine input and output: Input: Deviation e = set temperature - actual temperature, deviation change rate ec = (et - et - 1) / Δt; Output: PID parameter adjustment ΔKp, ΔKi, ΔKd; Fuzzification: fuzzify the input variables, i.e. map them to fuzzy sets; Establish fuzzy rules: establish a fuzzy rule base to describe the relationship between input and output; If e is positive and large and ec is zero, then ΔKp is positive and large, ΔKi is negative and small, and ΔKd is zero; Fuzzy reasoning: Based on the fuzzy rule base and the fuzzy values ​​of the input variables, fuzzy reasoning is performed to obtain the fuzzy values ​​of the output variables. Defuzzification: Defuzzify the fuzzy value of the output variable to obtain the adjustment amount of PID parameters ΔKp, ΔKi, ΔKd; Update PID parameters: Update PID parameters using adjustment values: Kp=Kp+ΔKp; Ki=Ki+ΔKi; Kd=Kd+ΔKd; Calculate the control quantity: Use the updated PID parameters to calculate the control quantity: Control quantity = Kp*e+Ki*∫edt+Kd*de / dt; Repeat the above steps: Repeat the above steps until the wellhead asphalt is softened.

5. The method for regulating the height difference of a trenchless anti-settling manhole cover according to claim 1, characterized in that: The heat conduction model includes: Radiative heat transfer: q_rad=ε*σ*(T_heater^4-T_surface^4); Where q_rad is the radiative heat flux, ε is the emissivity of the heating plate, σ is the Stefan-Boltzmann constant, T_heater is the surface temperature of the heating plate, and T_surface is the surface temperature of the asphalt pavement. Radiative heat transfer is proportional to the fourth power of temperature. Heat conduction inside asphalt: ρ is the density of asphalt mixture (kg / m 3 ), c is the specific heat capacity of asphalt mixture, t is time, x is depth, is the partial derivative of temperature with respect to time, is the second-order partial derivative of temperature with respect to depth, and q is the heat source term; During the asphalt heating process, q mainly comes from radiation heat transfer, and boundary conditions are used to introduce radiation heat flux into the heat conduction equation; It represents the heat flux transferred from the inside of the pavement to the surface through heat conduction, and the negative sign indicates that heat flows from the high-temperature area to the low-temperature area; q_rad represents the radiation heat flux; h represents the surface heat transfer coefficient, which describes the efficiency of heat exchange between the pavement surface and the surrounding air through convection; T_surface represents the temperature of the asphalt pavement surface; and T_ambient represents the ambient temperature.

6. A trenchless anti-settling manhole cover height difference control method according to claim 5, characterized in that: Based on the heat conduction model, a gradient heating strategy is optimized to predict the heating time based on a fixed heating distance. The gradient heating strategy includes: To find the best gradient heating strategy, a mathematical model was established to describe the temperature distribution between the upper and lower layers of the asphalt pavement: The one-dimensional unsteady heat conduction equation can approximately describe the change of pavement temperature with time and depth: ρ is the density of asphalt, c is the specific heat capacity of asphalt, T(x, t) is the temperature at depth x and time t, k is the thermal conductivity of asphalt, and Q(x, t) is the heat source intensity at depth x and time t; Objective function: The optimization goal is to minimize the heating time and temperature error while satisfying the constraints; Where: t_heating is the heating time, T_target(x) is the target temperature at depth x, w_t and w_e are weight coefficients used to balance the heating time and temperature error, and L is the road surface depth; Constraints: Maximum surface temperature constraint: T(0, t) ≤ T_max; Target temperature range of each layer: T_min(x)≤T(x, t_heating)≤T_max(x).

7. A trenchless anti-settlement manhole cover height difference regulation system, applied to a trenchless anti-settlement manhole cover height difference regulation method according to any one of claims 1 to 6, characterized in that: The system comprises: Wellhead safety and explosion-proof unit: includes high-temperature resistant rubber airbags, screw nuts, plane bearings, upper and lower steel plates and inner cylinder, aerogel blanket insulation layer, and combustible gas monitoring module, used to isolate combustible gases in the well and prevent heat leakage; High-frequency heating unit: It consists of a high-frequency electromagnetic induction coil and an infrared temperature control system. It is used to quickly and directionally heat the anti-subsidence manhole cover to 160-180°C. The heat is transferred to the asphalt pavement interface with the anti-subsidence manhole cover at a depth of 10-20mm, so that the asphalt bonded to the manhole cover reaches a softening temperature of 100°C. The temperature of the inner cylinder of the anti-subsidence manhole cover is controlled to be ≤180°C, and the temperature of the flange is 120°C. Lifting device unit: including screw jack, I-beam support frame and L-shaped hook plate, used for non-destructive separation of anti-settlement manhole cover and asphalt pavement; Asphalt in-situ heating unit: consists of a modular graphene far-infrared heating plate and a PID temperature control system, supports gradient heating control, and is equipped with an aluminum foil reflective layer and an aerogel blanket insulation layer to improve energy efficiency.

8. The trenchless anti-settling manhole cover height difference control system according to claim 7, characterized in that: The induction coil of the high-frequency heating unit is a spiral ring structure, and its inner diameter matches the diameter of the anti-subsidence manhole cover limiting cylinder. The electromagnetic power is dynamically adjusted through the PID algorithm to achieve precise decoupling of the anti-subsidence manhole cover-asphalt interface.

9. The trenchless anti-settling manhole cover height difference control system according to claim 7, characterized in that: The modular graphene far-infrared heating plate of the asphalt in-situ heating unit is spliced ​​into a heating trolley by two sub-units. The heating plate is fixed to the mobile trolley with a buckle, and each sub-unit is equipped with an independent temperature control circuit. The PID algorithm dynamically adjusts the power; it is wrapped with an aerogel blanket to reduce heat loss.

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